阅读说明：本技术 氟聚合物水性分散液的制造方法和氟聚合物水性分散液 (Method for producing aqueous fluoropolymer dispersion and aqueous fluoropolymer dispersion ) 是由 林忠雄 平良隆博 吉田裕俊 奥井千亚纪 山中拓 加藤丈人 于 2020-04-27 设计创作，主要内容包括：一种精制氟聚合物水性分散液的制造方法,其特征在于,其包括使利用烃系表面活性剂得到的氟聚合物水性分散液与阴离子交换树脂A或合成吸附剂接触的工序A,上述阴离子交换树脂A具有下述通式(A1)：-N～(+)R～(1)R～(2)R～(3)X～(-)(式中,R～(1)、R～(2)和R～(3)相同或不同地为氢原子或有机基团,R～(1)、R～(2)和R～(3)中的至少1个是碳原子数为3以上的有机基团。X为抗衡离子。)所表示的离子交换基、或下述通式(A2)：-NR～(4)R～(5)(式中,R～(4)和R～(5)相同或不同地为氢原子或有机基团,R～(4)和R～(5)中的至少1个是碳原子数为2以上的有机基团。)所表示的离子交换基。(A process for producing a purified aqueous fluoropolymer dispersion, which comprises a step A of bringing an aqueous fluoropolymer dispersion obtained using a hydrocarbon surfactant into contact with an anion exchange resin A or a synthetic adsorbent, wherein the anion exchange resin A has the following general formula (A1): -N + R 1 R 2 R 3 X ‑ (in the formula, R 1 、R 2 And R 3 Identically or differently hydrogen atoms or organic radicals, R 1 、R 2 And R 3 At least 1 of them is an organic group having 3 or more carbon atoms. X is a counter ion. ) An ion exchange group represented by the following general formula (A2): -NR 4 R 5 (in the formula, R 4 And R 5 Identically or differently hydrogen atoms or organic radicals, R 4 And R 5 At least 1 of them is an organic group having 2 or more carbon atoms. ) The ion exchange groups are shown.)

1. A process for producing a purified aqueous fluoropolymer dispersion, which comprises a step A of bringing an aqueous fluoropolymer dispersion obtained using a hydrocarbon surfactant into contact with an anion exchange resin A or a synthetic adsorbent,

the anion exchange resin A has an ion exchange group represented by the following general formula (A1) or an ion exchange group represented by the following general formula (A2),

General formula (a 1): -N⁺R¹R²R³X^-

In the formula, R¹、R²And R³Identically or differently hydrogen atoms or organic radicals, R¹、R²And R³At least 1 of which is an organic group having 3 or more carbon atoms, X is a counter ion,

general formula (a 2): -NR⁴R⁵

In the formula, R⁴And R⁵Identically or differently hydrogen atoms or organic radicals, R⁴And R⁵At least 1 of them is an organic group having 2 or more carbon atoms.

2. The production process according to claim 1, wherein in the general formula (A1), R¹、R²And R³At least 1 of them is an organic group having 4 or more carbon atoms.

3. The production process according to claim 1 or 2, wherein in the general formula (A1), R¹、R²And R³Is an organic group having 2 or more carbon atoms.

4. The production process according to any one of claims 1 to 3, wherein the synthetic adsorbent has a pore volume of 0.6cm³/g～2.5cm³/g。

5. The production method according to any one of claims 1 to 4, wherein the step A is performed 2 or more times.

6. The production process according to any one of claims 1 to 5, further comprising a step B of bringing the aqueous fluoropolymer dispersion into contact with an anion exchange resin B,

the anion exchange resin B is different from the anion exchange resin A.

7. The production process according to claim 6, wherein the anion exchange resin B has an ion exchange group represented by the following general formula (B1) or an ion exchange group represented by the following general formula (B2),

General formula (B1): -N⁺(CH₃)₃X^-

Wherein X represents a counter ion,

general formula (B2): -N⁺(CH₃)₂(C₂H₄OH)X^-

Wherein X represents a counter ion.

8. The production method according to claim 6 or 7, wherein the step B is performed before the step A.

9. The production process according to any one of claims 1 to 8, further comprising a step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion having undergone the step A and performing phase separation and concentration.

10. The production method according to claim 9, wherein the step C is performed 2 or more times.

11. The process according to claim 10, wherein the phase separation and concentration in the 1 st step C comprises heating the aqueous fluoropolymer dispersion at a temperature 5 ℃ or higher than the cloud point of the nonionic surfactant, and then allowing the heated aqueous fluoropolymer dispersion to stand to separate into a supernatant phase and a concentrated phase.

12. The process according to claim 10 or 11, wherein the phase separation and concentration in the 2 nd step C is carried out by heating the aqueous fluoropolymer dispersion at a temperature 5 ℃ or higher than the cloud point of the nonionic surfactant and then allowing the heated aqueous fluoropolymer dispersion to stand to separate into a supernatant phase and a concentrated phase.

13. An aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that,

Which comprises a compound represented by the following general formula (1), wherein the total content of the compound represented by the following general formula (1) is 1000ppb or less relative to the fluoropolymer,

general formula (1): (H- (CF)₂)_m-COO)_pM¹

Wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, p is 1 or 2, R⁵The same or different, and is H or an organic group having 1 to 10 carbon atoms.

Technical Field

The present invention relates to a method for producing an aqueous fluoropolymer dispersion and an aqueous fluoropolymer dispersion.

Background

In the case of producing a fluoropolymer by emulsion polymerization, a fluorinated anionic surfactant is used. Recently, it has been proposed to use a hydrocarbon surfactant instead of a fluorinated anionic surfactant (see, for example, patent documents 1 to 3).

Documents of the prior art

Patent document

Patent document 1: specification of U.S. Pat. No. 9255164

Patent document 2: specification of U.S. Pat. No. 8563670

Patent document 3: specification of U.S. Pat. No. 9074025

Disclosure of Invention

Problems to be solved by the invention

The present invention provides a method for producing an aqueous fluoropolymer dispersion, which can reduce the amount of a specific fluorine-containing compound even when obtained using a hydrocarbon surfactant. Further, the present invention provides a novel aqueous fluoropolymer dispersion having a reduced amount of a specific fluorine-containing compound.

Means for solving the problems

The present invention relates to a method for producing a purified aqueous fluoropolymer dispersion, which comprises a step A of bringing an aqueous fluoropolymer dispersion obtained using a hydrocarbon surfactant into contact with an anion exchange resin A or a synthetic adsorbent, wherein the anion exchange resin A has the following general formula (A1):

-N⁺R¹R²R³X^-

(in the formula, R¹、R²And R³Identically or differently hydrogen atoms or organic radicals, R¹、R²And R³At least 1 of them is an organic group having 3 or more carbon atoms. X is a counter ion. ) An ion exchange group represented by the following general formula (A2):

-NR⁴R⁵

(in the formula, R ⁴And R⁵Identically or differently hydrogen atoms or organic radicals, R⁴And R⁵At least 1 of them is an organic group having 2 or more carbon atoms. ) The ion exchange groups are shown.

In the general formula (A1), R is preferred¹、R²And R³At least 1 of them is an organic group having 4 or more carbon atoms. In addition, in the general formula (A1), R is also preferable¹、R²And R³Is an organic group having 2 or more carbon atoms.

The pore volume of the synthetic adsorbent is preferably 0.6-2.5 cm³/g。

In the production method of the present invention, the step a is preferably performed 2 or more times.

The production method of the present invention preferably further comprises a step B of bringing the aqueous fluoropolymer dispersion into contact with an anion exchange resin B different from the anion exchange resin a.

The above anion exchange resin B preferably has the following general formula (B1):

-N⁺(CH₃)₃X^-

(wherein X represents a counter ion.) or an ion exchange group represented by the following general formula (B2):

-N⁺(CH₃)₂(C₂H₄OH)X^-

(wherein X represents a counter ion.) or a salt thereof.

The step B is preferably performed before the step a.

The production method of the present invention preferably further comprises a step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion after the step a to perform phase separation and concentration, and more preferably, the step C is performed 2 or more times.

In the 1 st step C, the phase separation and concentration is preferably carried out by heating the aqueous fluoropolymer dispersion at a temperature 5 ℃ or higher than the cloud point of the nonionic surfactant, and then allowing the heated aqueous fluoropolymer dispersion to stand to separate into a supernatant phase and a concentrated phase.

In the 2 nd step C, the aqueous fluoropolymer dispersion is preferably heated at a temperature 5 ℃ or higher than the cloud point of the nonionic surfactant and then allowed to stand to separate into a supernatant phase and a concentrated phase.

The present invention also relates to an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the aqueous fluoropolymer dispersion contains a compound represented by the following general formula (1), and the total content of the compounds represented by the following general formula (1) is 1000ppb or less relative to the fluoropolymer.

General formula (1): (H- (CF)₂)_m-COO)_pM¹

(wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

ADVANTAGEOUS EFFECTS OF INVENTION

The production method of the present invention, which has the above-described configuration, can provide an aqueous fluoropolymer dispersion in which the amount of the specific fluorine-containing compound is reduced even when the aqueous fluoropolymer dispersion is obtained using a hydrocarbon surfactant.

Detailed Description

Before explaining the present invention in detail, several terms used in the present specification are defined or explained.

In the present specification, the fluororesin is a partially crystalline fluoropolymer and is a fluoroplastic. The fluororesin has a melting point and is thermoplastic, and may be melt-processable or non-melt-processable.

In the present specification, melt processability means that a polymer can be melted and processed using existing processing equipment such as an extruder and an injection molding machine. Therefore, the melt flow rate of the melt-processable fluororesin is usually 0.01 to 500g/10 min as measured by the measurement method described later.

In the present specification, the fluororubber is an amorphous fluoropolymer. The term "amorphous" means that the size of a melting peak (. DELTA.H) appearing in differential scanning calorimetry [ DSC ] (temperature rising rate of 10 ℃ C./min) or differential thermal analysis [ DTA ] (temperature rising rate of 10 ℃ C./min) of a fluoropolymer is 4.5J/g or less. Fluororubbers exhibit elastomeric properties by undergoing crosslinking. The elastomer properties refer to the following properties: the polymer can be stretched and can retain its original length when the force required to stretch the polymer is no longer applied.

In the present specification, the partially fluorinated rubber means the following fluoropolymer: comprises a fluoromonomer unit, has a content of a perfluoromonomer unit of less than 90 mol% relative to the total polymerized units, has a glass transition temperature of 20 ℃ or less, and has a melting peak (. DELTA.H) of 4.5J/g or less.

In the present specification, the perfluororubber (perfluoroelastomer) refers to the following fluoropolymer: the perfluoromonomer unit is contained in an amount of 90 mol% or more based on the total polymerized units, has a glass transition temperature of 20 ℃ or less, has a melting peak (. DELTA.H) of 4.5J/g or less, and has a fluorine atom concentration of 71 mass% or more in the fluoropolymer. In the present specification, the concentration of fluorine atoms contained in a fluoropolymer is calculated from the type and content of each monomer constituting the fluoropolymer to obtain the concentration (% by mass) of fluorine atoms contained in the fluoropolymer.

In the present specification, the perfluoro monomer means a monomer having no carbon atom-hydrogen atom bond in the molecule. The above-mentioned perfluoromonomer may be a monomer having, in addition to carbon atoms and fluorine atoms, some of the fluorine atoms bonded to the carbon atoms substituted with chlorine atoms; the monomer may have a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a boron atom, or a silicon atom in addition to a carbon atom. The perfluoro monomer is preferably a monomer in which all hydrogen atoms are substituted by fluorine atoms. The above-mentioned perfluoromonomers do not contain a monomer providing a crosslinking site.

The monomer providing the crosslinking site is a monomer (curing site monomer) having a crosslinkable group providing the crosslinking site for forming crosslinking by the curing agent to the fluoropolymer.

In the present specification, the content of each monomer constituting the fluoropolymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of the monomer.

In the present specification, the term "organic group" refers to a group containing 1 or more carbon atoms or a group formed by removing 1 hydrogen atom from an organic compound.

Examples of the "organic group" include

An alkyl group which may or may not have 1 or more substituents,

An alkenyl group which may have 1 or more substituents,

An alkynyl group which may have 1 or more substituents,

Cycloalkyl group which may have 1 or more substituents,

Cycloalkenyl having or not having 1 or more substituents,

A cycloalkadienyl group which may or may not have 1 or more substituents,

An aryl group which may or may not have 1 or more substituents,

An aralkyl group which may or may not have 1 or more substituents,

A non-aromatic heterocyclic group which may have 1 or more substituents,

A heteroaryl group which may or may not have 1 or more substituents,

A cyano group,

Formyl, methyl,

RaO-、

RaCO-、

RaSO₂-、

RaCOO-、

RaNRaCO-、

RaCONRa-、

RaOCO-、

RaOSO₂-and

RaNRbSO₂-

(in the formulae, Ra is independently

An alkyl group which may or may not have 1 or more substituents,

An alkenyl group which may have 1 or more substituents,

An alkynyl group which may have 1 or more substituents,

Cycloalkyl group which may have 1 or more substituents,

Cycloalkenyl having or not having 1 or more substituents,

A cycloalkadienyl group which may or may not have 1 or more substituents,

An aryl group which may or may not have 1 or more substituents,

An aralkyl group which may or may not have 1 or more substituents,

A non-aromatic heterocyclic group which may have 1 or more substituents, or

A heteroaryl group with or without 1 or more substituents,

rb is independently H or alkyl with or without 1 or more substituents).

The organic group is preferably an alkyl group having 1 or more substituents.

In the present specification, the term "substituent" refers to a group which can be substituted. Examples of the "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl oxy group, a sulfamoyl group, an aliphatic sulfonamide group, an aromatic sulfonamide group, a heterocyclic sulfonamide group, an amino group, an aliphatic amino group, an aromatic amino group, a heterocyclic amino group, an aliphatic oxycarbonylamino group, an aromatic oxycarbonylamino group, a heterocyclic oxycarbonylamino group, an aliphatic sulfinyl group, an aromatic sulfinyl group, an aliphatic thio group, an aromatic thio group, a hydroxyl group, a cyano group, a sulfo group, a carboxyl group, an aliphatic oxyamino group, an aromatic oxyamino group, a carbamoylamino group, Sulfamoylamino, a halogen atom, sulfamoylcarbamoyl, carbamoylsulfamoyl, dialiphatic oxyphosphinyl and diaromatic oxyphosphinyl.

The aliphatic group may be saturated or unsaturated, and may have a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the aliphatic group include alkyl groups having 1 to 8, preferably 1 to 4, total carbon atoms, such as methyl, ethyl, vinyl, cyclohexyl, and carbamoylmethyl groups.

The aromatic group may have, for example, a nitro group, a halogen atom, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the aromatic group include aryl groups having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms in total, such as phenyl, 4-nitrophenyl, 4-acetylaminophenyl, 4-methylsulfonylphenyl and the like.

The heterocyclic group may have a halogen atom, a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group or the like. Examples of the heterocyclic group include 5-to 6-membered heterocyclic rings having 2 to 12, preferably 2 to 10, total carbon atoms, for example, 2-tetrahydrofuranyl group, 2-pyrimidinyl group and the like.

The acyl group may have an aliphatic carbonyl group, an arylcarbonyl group, a heterocyclic carbonyl group, a hydroxyl group, a halogen atom, an aromatic group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the acyl group include acyl groups having 2 to 8, preferably 2 to 4, total carbon atoms, such as an acetyl group, a propionyl group, a benzoyl group, and a 3-pyridinecarbonyl group.

The acylamino group may have an aliphatic group, an aromatic group, a heterocyclic group, etc., and may have, for example, an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propionylamino group, etc. Examples of the acylamino group include acylamino groups having 2 to 12, preferably 2 to 8, total carbon atoms, alkylcarbonylamino groups having 2 to 8 total carbon atoms, for example, acetylamino group, benzoylamino group, 2-pyridinecarbonylamino group, propionylamino group and the like.

The aliphatic oxycarbonyl group may be saturated or unsaturated, and may have a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the aliphatic oxycarbonyl group include an alkoxycarbonyl group having 2 to 8, preferably 2 to 4, total carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a tert-butoxycarbonyl group.

The carbamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, or the like. Examples of the carbamoyl group include an unsubstituted carbamoyl group and an alkylcarbamoyl group having 2 to 9 total carbon atoms, and preferable examples thereof include an unsubstituted carbamoyl group and an alkylcarbamoyl group having 2 to 5 total carbon atoms, such as an N-methylcarbamoyl group, an N, N-dimethylcarbamoyl group and an N-phenylcarbamoyl group.

The aliphatic sulfonyl group may be saturated or unsaturated, and may have a hydroxyl group, an aromatic group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the aliphatic sulfonyl group include alkylsulfonyl groups having 1 to 6 total carbon atoms, preferably 1 to 4 total carbon atoms, for example, methylsulfonyl group and the like.

The aromatic sulfonyl group may have a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group or the like. Examples of the aromatic sulfonyl group include arylsulfonyl groups having 6 to 10 total carbon atoms, for example, benzenesulfonyl groups.

The amino group may have an aliphatic group, an aromatic group, a heterocyclic group, or the like.

The acylamino group may have, for example, acetylamino group, benzoylamino group, 2-pyridinecarbonylamino group, propionylamino group, etc. Examples of the acylamino group include acylamino groups having 2 to 12 total carbon atoms, preferably 2 to 8 total carbon atoms, more preferably alkylcarbonylamino groups having 2 to 8 total carbon atoms, for example acetylamino group, benzoylamino group, 2-pyridinecarbonylamino group, propionylamino group and the like.

The aliphatic sulfonamide group, the aromatic sulfonamide group and the heterocyclic sulfonamide group may be, for example, a methanesulfonamide group, a benzenesulfonamide group or a 2-pyridinesulfonamide group.

The sulfamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, or the like. The sulfamoyl group includes a sulfamoyl group, an alkylsulfamoyl group having 1 to 9 total carbon atoms, a dialkylsulfamoyl group having 2 to 10 total carbon atoms, an arylsulfamoyl group having 7 to 13 total carbon atoms, and a heterocyclic sulfamoyl group having 2 to 12 total carbon atoms, and more preferably includes a sulfamoyl group, an alkylsulfamoyl group having 1 to 7 total carbon atoms, a dialkylsulfamoyl group having 3 to 6 total carbon atoms, an arylsulfamoyl group having 6 to 11 total carbon atoms, and a heterocyclic sulfamoyl group having 2 to 10 total carbon atoms, such as a sulfamoyl group, a methylsulfamoyl group, an N, N-dimethylsulfamoyl group, a phenylsulfamoyl group, and a 4-pyridinesulfamoyl group.

The aliphatic oxy group may be saturated or unsaturated, and may have methoxy, ethoxy, isopropoxy, cyclohexyloxy, methoxyethoxy, or the like. Examples of the aliphatic oxy group include alkoxy groups having 1 to 8, preferably 1 to 6, total carbon atoms, for example, methoxy group, ethoxy group, isopropoxy group, cyclohexyloxy group, methoxyethoxy group, and the like.

The aromatic amino group and the heterocyclic amino group may have an aliphatic group, an aliphatic oxy group, a halogen atom, a carbamoyl group, a heterocyclic group condensed with the aryl group, and an aliphatic oxycarbonyl group, and preferably may have an aliphatic group having 1 to 4 total carbon atoms, an aliphatic oxy group having 1 to 4 total carbon atoms, a halogen atom, a carbamoyl group having 1 to 4 total carbon atoms, a nitro group, and an aliphatic oxycarbonyl group having 2 to 4 total carbon atoms.

The aliphatic thio group may be saturated or unsaturated, and examples thereof include alkylthio groups having 1 to 8 total carbon atoms, more preferably 1 to 6 total carbon atoms, such as methylthio, ethylthio, carbamoylmethylthio, and tert-butylthio.

The carbamoylamino group may have an aliphatic group, an aryl group, a heterocyclic group or the like. The carbamoylamino group includes a carbamoylamino group, an alkylcarbamoylamino group having 2 to 9 total carbon atoms, a dialkylcarbamoylamino group having 3 to 10 total carbon atoms, an arylcarbamoylamino group having 7 to 13 total carbon atoms, and a heterocyclic carbamoylamino group having 3 to 12 total carbon atoms, and preferably includes a carbamoylamino group, an alkylcarbamoylamino group having 2 to 7 total carbon atoms, a dialkylcarbamoylamino group having 3 to 6 total carbon atoms, an arylcarbamoylamino group having 7 to 11 total carbon atoms, a heterocyclic carbamoylamino group having 3 to 10 total carbon atoms, for example, a carbamoylamino group, a methylcarbamoylamino group, an N, N-dimethylcarbamoylamino group, a phenylcarbamoylamino group, a 4-pyridinecarbamoylamino group, and the like.

In the present specification, the range represented by the endpoints includes all the numerical values contained in the range (for example, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

In the present specification, a description of "at least 1" includes all numerical values of 1 or more (for example, at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, and the like).

In the present specification, unless otherwise specified, ppm and ppb mean values obtained by mass conversion.

Next, the production process of the present invention and the aqueous fluoropolymer dispersion of the present invention will be specifically described.

The process for producing a purified aqueous fluoropolymer dispersion according to the present invention comprises a step A of bringing an aqueous fluoropolymer dispersion obtained using a hydrocarbon surfactant into contact with an anion exchange resin A or a synthetic adsorbent, wherein the anion exchange resin A has the following general formula (A1):

-N⁺R¹R²R³X^-

(in the formula, R¹、R²And R³Identically or differently hydrogen atoms or organic radicals, R¹、R²And R³At least 1 of them is an organic group having 3 or more carbon atoms. X represents a counter ion. ) An ion exchange group represented by the following general formula (A2):

-NR⁴R⁵

(in the formula, R⁴And R⁵Identically or differently hydrogen atoms or organic radicals, R ⁴And R⁵At least 1 of them is an organic group having 2 or more carbon atoms. ) The ion exchange groups are shown. By bringing the aqueous fluoropolymer dispersion into contact with the above-mentioned specific anion exchange resin or synthetic adsorbent, it is possible to efficiently remove the specific fluorine-containing compound from the aqueous fluoropolymer dispersion.

In the production method of the present invention, the "purified aqueous fluoropolymer dispersion" is not limited as long as it is an aqueous fluoropolymer dispersion obtained through at least the step a.

In the present specification, unless otherwise specified, the term "aqueous fluoropolymer dispersion" refers to an aqueous fluoropolymer dispersion to be subjected to the above-mentioned step a (and further, if necessary, to the steps B, C, etc., described later).

In the general formula (A1), R¹、R²And R³Identical or different are hydrogen atoms or organic groups. R¹、R²And R³All of them may be organic groups, or 1 hydrogen atom and 2 organic groups may be used. Further, 2 may be hydrogen atoms and 1 may be an organic group. The organic group has 1 or more carbon atoms. The organic group preferably has 2 or more carbon atoms. R is as defined above¹、R²And R³An organic group having 2 or more carbon atoms is one of the preferred embodiments.

In the general formula (A1), R is as defined above¹、R²And R³At least 1 of them is an organic group having 3 or more carbon atoms. R¹、R²And R³In (3), 1 organic group having 3 or more carbon atoms and 2 organic groups having 1 or 2 hydrogen atoms or carbon atoms may be used. In addition, 2 organic groups having 3 or more carbon atoms and 1 organic group having 1 or 2 hydrogen atoms or carbon atoms may be used. R¹、R²And R³All of the organic groups may be organic groups having 3 or more carbon atoms.

R is as defined above¹、R²And R³In the above, the number of carbon atoms of the organic group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The organic group may have 5 or less carbon atoms.

In the general formula (A1), R is preferred¹、R²And R³At least 1 of them is an organic group having 4 or more carbon atoms. By adopting such a constitution, the specific fluorine-containing compound can be more efficiently removed.

R is as defined above¹、R²And R³The organic group in (2) is preferably an alkyl group, an alkanol group or an alkenyl group, more preferably an alkyl group or an alkanol group, and still more preferably an alkyl group.

In the present specification, "alkyl" is a general term for a group remaining after removing 1 hydrogen atom from an aliphatic saturated hydrocarbon, and includes both a linear or branched alkyl group having 1 or more carbon atoms and a cyclic alkyl group having 3 or more carbon atoms.

In the present specification, the term "alkanol group" refers to a general term for a group remaining after removing 1 hydrogen atom from an alkanol, and includes both straight-chain or branched alkanol groups having 1 or more carbon atoms and cyclic alkanol groups having 3 or more carbon atoms.

Preferably R is as defined above¹、R²And R³Is alkyl with more than 2 carbon atoms or alkanol with more than 1 carbon atom, and R¹、R²And R³At least 1 of them is an alkyl group having 3 or more carbon atoms.

R is as defined above¹、R²And R³Is alkyl with more than 2 carbon atoms or alkanol with more than 2 carbon atoms, and R is¹、R²And R³At least 1 of them is an alkyl group having 3 or more carbon atoms, which is one of more preferable embodiments.

In addition, the above R¹、R²And R³Is alkyl with more than 2 carbon atoms or alkanol with more than 1 carbon atom, and R is¹、R²And R³At least 1 of them is an alkyl group having 4 or more carbon atoms.

In addition, the above R¹、R²And R³Is alkyl with more than 2 carbon atoms or alkanol with more than 2 carbon atoms, and R is¹、R²And R³At least 1 of them is an alkyl group having 4 or more carbon atoms.

The number of carbon atoms of the alkyl group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The alkyl group may have 5 or less carbon atoms.

The number of carbon atoms of the alkanol group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The number of carbon atoms of the alkanol group may be 5 or less.

In the general formula (A1), X is a counter ion. Examples of X include Cl, OH, Br, I and NO₃、SO₄Etc., preferably Cl or OH. It is to be noted that in the case of SO₄In the case of such a 2-valent anion, 1 counter ion is coordinated to 2 repeating units of the general formula (a 1).

In the above general formula (A2), R⁴And R⁵Identically or differently hydrogen atoms or organic radicals, R⁴And R⁵At least 1 of them is an organic group having 2 or more carbon atoms.

R⁴And R⁵May be all organic groups. Further, 1 may be a hydrogen atom and 1 may be an organic group.

In the general formula (A2), R is as defined above⁴And R⁵At least 1 of them is an organic group having 2 or more carbon atoms.

R⁴And R⁵In (3), 1 organic group having 2 or more carbon atoms, and 1 organic group having 1 hydrogen atom or carbon atom may be used. In addition, R⁴And R⁵Both of them may be organic groups having 2 or more carbon atoms.

R is as defined above⁴And R⁵At least 1 of them may be an organic group having 3 or more carbon atoms, or an organic group having 4 or more carbon atoms.

In addition, the above R⁴And R⁵Also preferred is an organic group having 2 or more carbon atoms.

R is as defined above⁴And R⁵In the above, the number of carbon atoms of the organic group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The organic group may have 5 or less carbon atoms.

R is as defined above⁴And R⁵The organic group in (2) is preferably an alkyl group, an alkanol group or an alkenyl group, more preferably an alkyl group or an alkanol group, and still more preferably an alkyl group.

R is as defined above⁴And R⁵Identically or differently, alkyl or alkanol radicals, R mentioned above⁴And R⁵At least 1 of them is an alkyl group having 2 or more carbon atoms or an alkanol group having 2 or more carbon atoms, which is one of more preferable embodiments.

The number of carbon atoms of the alkyl group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The alkyl group may have 5 or less carbon atoms.

The number of carbon atoms of the alkanol group is preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. The number of carbon atoms of the alkanol group may be 5 or less.

The anion exchange resin a is preferably a resin having a group represented by the general formula (a1) or a group represented by the general formula (a2) bonded to a resin matrix. Examples of the anion exchange resin a include resins in which a group represented by the general formula (a1) or a group represented by the general formula (a2) is bonded to a resin matrix composed of a styrene-based or acrylic polymer. The styrenic or acrylic polymer as the resin matrix is not limited, and for example, a resin matrix used in a known anion exchange resin can be used. The resin matrix of the anion exchange resin a is preferably styrene, from the viewpoint of the removal efficiency of the fluorine-containing compound.

The basicity of the anion exchange resin a can be variously set depending on the polymer backbone and/or the kind of the ion exchange group.

The pore diameter of the anion exchange resin A is preferably set to be in the range ofFrom the viewpoint of removal efficiency, the pore diameter is preferably set to be smallAbove, more preferablyThe above is more preferableThe above. In addition, can beAs above, the above may beThe above. In addition, the pore diameter may beThe following. The pore diameter can be calculated by measuring the specific surface area and the total pore volume by a gas adsorption method, for example.

From the viewpoint of removal efficiency, the total exchange capacity of the anion exchange resin A is preferably 0.1 eq/L-resin or more. More preferably 0.3 eq/L-resin or more, still more preferably 0.5 eq/L-resin or more, and particularly preferably 0.7 eq/L-resin or more. The upper limit is preferably 5.0 eq/L-resin or less, more preferably 2.0 eq/L-resin or less, and particularly preferably 1.5 eq/L-resin or less.

The water content of the anion exchange resin a is preferably 20% by mass or more, more preferably 30 to 70% by mass, and further preferably 35 to 65% by mass. By setting the moisture content of the anion exchange resin a to 30% by mass or more, the fluorine-containing compound can be efficiently removed. Further, the fluorine-containing compound is easily diffused into the particles of the anion exchange resin A. When the moisture content of the anion exchange resin a is 70% by mass or less, the decrease in the particle strength of the anion exchange resin a due to insufficient crosslinking can be suppressed.

The moisture content can be measured by the following method.

First, 10mL of a sample prepared in a standard shape was accurately weighed using a measuring cylinder, the resin was wrapped in a cloth and centrifuged to remove attached water, and then the mass of the resin was measured quickly. Subsequently, the resin was dried in a thermostatic dryer at 105 ℃ for 4 hours, then naturally cooled in a dryer for 30 minutes, and the mass of the dried resin was weighed to calculate the moisture content by the following formula.

Moisture content (% by mass) is (mass (g) of resin before drying — mass (g) of resin after drying))/mass (g) of resin before drying × 100

The anion exchange resin A is usually spherical. The average particle diameter of the anion exchange resin A is preferably 0.1 to 5mm, more preferably 0.2 to 2mm, and particularly preferably 0.3 to 1.5 mm. When the average particle diameter of the anion exchange resin a is within the above range, the packed column of the anion exchange resin is less likely to be clogged. The average particle diameter is a value obtained by a sieving method. Specifically, first, the anion exchange resin a was taken into a sieve shaker, and the particle size distribution was measured by sieving. Then, the diameter of the mesh corresponding to 50% of the residual classifier was obtained and used as the average particle diameter.

As the anion exchange resin A, commercially available products can be used, and examples thereof include PFA694E and A592E manufactured by Purolite corporation.

The synthetic adsorbent is a porous resin having no ion exchange group, and a known synthetic adsorbent can be used. Examples of the ion exchange group include an amino group, a quaternary ammonium group, a carboxylic acid group, and a sulfonic acid group. Specific examples of the synthetic adsorbent include styrene resins such as styrene-divinylbenzene copolymers, acrylic resins such as (meth) acrylate-ethylene glycol dimethacrylate copolymers, methacrylic resins, polyvinyl resins, and dextran resins. Examples of commercially available synthetic adsorbents include, specifically, styrene resins such as Diaion HP10, Diaion HP20, Diaion HP21, Diaion HP40, Diaion HP50, SEPABEADS SP207, SEPABEADS SP70, SEPABEADS SP825, SEPABEADS SP850, SEPABEADS SP207 (manufactured by mitsubishi chemical corporation, supra), Amberlite XAD1180N, Amberlite XAD2000, Amberlite XAD4, and Amberlite FPX66 (manufactured by dupont corporation, supra); examples of the acrylic resin include Diaion HP2MG (manufactured by Mitsubishi chemical corporation) and Amberlite HXAD-7HP (manufactured by DuPont corporation).

The pore size of the synthetic adsorbent is preferablyFrom the viewpoint of removal efficiency, the pore diameter is preferably set to be smallAbove, more preferablyThe above is more preferableThe above. In addition, can beAs above, the above may beThe above. In addition, the pore diameter may beHereinafter, the following may beThe following. The pore diameter can be calculated by measuring the specific surface area and the total pore volume by a gas adsorption method, for example.

The specific surface area of the synthetic adsorbent is preferably 300m²More than g. The specific surface area is more preferably 400m²A total of 500m or more²(ii) at least g, particularly preferably 600m²More than g. The upper limit of the specific surface area is not limited, and may be 2000m, for example²(ii) less than g, and may be 1500m²A ratio of 1000m or less per gram²The ratio of the carbon atoms to the carbon atoms is less than g. The preferred pore volume of the synthetic adsorbent is 0.6-2.5 cm³(ii) in terms of/g. More preferably 0.9 to 2.3cm³(ii) g, more preferably 1.1 to 2.1cm³A specific preferred concentration is 1.3 to 2.0cm³(ii) in terms of/g. Pore volume is less than 0.6cm³At the time of the reaction,/g, the adsorption of the fluorine-containing compound may be decreased to more than 2.5cm³At/g, the adsorbent may break. The pore volume is a value measured by a nitrogen method.

The synthetic adsorbent preferably contains water from the viewpoint of improving the removal efficiency of the fluorine-containing compound. The water content is preferably 20 to 80% by mass, more preferably 40 to 75% by mass, and particularly preferably 50 to 70% by mass. When the water content of the synthetic adsorbent is less than 20% by mass, the removal efficiency of the fluorine-containing compound may be lowered, and when it exceeds 80% by mass, weighing may become unstable.

Synthetic adsorbents are typically spherical. The average particle size of the synthetic adsorbent is preferably 0.1 to 2.0mm, more preferably 0.2 to 1.5mm, and particularly preferably 0.3 to 1.0 mm. When the average particle diameter of the synthetic adsorbent is less than 0.1mm, separation may be difficult after contact with the aqueous fluoropolymer dispersion, and when it exceeds 2.0mm, the removal efficiency of the fluorine-containing compound may be lowered. The average particle diameter of the synthetic adsorbent means a 50% mass value obtained by plotting the integrated mass after classification with a sieve.

The temperature in the step A is not particularly limited, and may be, for example, 0 to 50 ℃. From the viewpoint of improving the removal efficiency, it is preferably 5 ℃ or higher. Further, it is preferably 40 ℃ or lower, more preferably 35 ℃ or lower. Further, the temperature may be 20 ℃ or lower.

The pressure in the step a is not particularly limited, and may be, for example, 0.1 to 10 atmospheres, and may be carried out under normal pressure (about 1 atmosphere).

The contact time in the step a is not particularly limited, and may be 0.1 second to 100 hours, 1 second to 50 hours, or 1 second to 10 hours. Further, the time may be 1 second to 1 hour.

In the step A, the amount of the anion exchange resin A or the synthetic adsorbent to the aqueous fluoropolymer dispersion is not limited, and may be, for example, 0.01 to 1000g per 1000g of the aqueous fluoropolymer dispersion. The amount of the aqueous fluoropolymer dispersion is preferably 0.1g or more, more preferably 1g or more, and still more preferably 5g or more, per 1000g of the aqueous fluoropolymer dispersion. Further, it is preferably 500g or less.

The step a may be a step of: after the aqueous fluoropolymer dispersion is brought into contact with the anion exchange resin A or the synthetic adsorbent, the aqueous fluoropolymer dispersion is separated from the anion exchange resin A or the synthetic adsorbent, and the aqueous fluoropolymer dispersion (purified aqueous fluoropolymer dispersion) is recovered, and the anion exchange resin A or the synthetic adsorbent is recovered.

In the production method of the present invention, the contact in the step a may be a batch type or a flow type.

The step a may be performed 1 time or repeated 2 or more times. The step a is preferably performed 2 or more times, because the fluorine-containing compound can be further reduced. The upper limit of the number of times is not limited, and may be, for example, 10 times or less.

As a method for bringing the aqueous fluoropolymer dispersion into contact with the anion exchange resin a or the synthetic adsorbent, a conventionally employed method can be employed. For example, the dispersion can be carried out by a method of adding the anion exchange resin a or the synthetic adsorbent to the aqueous fluoropolymer dispersion and stirring the mixture, a column method of injecting the aqueous fluoropolymer dispersion into a column packed with the anion exchange resin a or the synthetic adsorbent, or the like. The packed column used in the column method may be any of a moving type, a fixed bed type, or a fluidized bed type.

When a method of adding the anion exchange resin a or the synthetic adsorbent to the aqueous fluoropolymer dispersion and stirring the mixture is used, it is preferable to include a separation step of separating the anion exchange resin a or the synthetic adsorbent from the aqueous fluoropolymer dispersion after the step a. The method for separating the anion exchange resin a or the synthetic adsorbent from the aqueous fluoropolymer dispersion after step a is not limited, and for example, filtration or the like can be used.

The production method of the present invention preferably further comprises a step B of bringing the aqueous fluoropolymer dispersion into contact with the anion exchange resin B.

The anion exchange resin B may be the same as or different from the anion exchange resin a, and is preferably different from the anion exchange resin a.

The anion exchange resin B preferably has an ion exchange group (excluding the group represented by the general formula (a1) and the group represented by the general formula (a 2)), and for example, preferably has an amino group and/or a quaternary ammonium group. As the above ion exchange group, the following general formula (B1) is preferred:

-N⁺(CH₃)₃X^-

(wherein X represents a counter ion.) or a group represented by the following general formula (B2):

-N⁺(CH₃)₂(C₂H₄OH)X^-

(wherein X represents a counter ion.) is used. Examples of X in the general formulae (B1) and (B2) include Cl, OH, Br, I, and NO ₃、SO₄Etc., preferably Cl or OH. It is to be noted that in the case of SO₄In the case of such a 2-valent anion, 1 counter ion is coordinated to 2 repeating units of the general formula (a 1).

The anion exchange resin B is preferably a resin having the ion exchange group bonded to a resin matrix, and examples of the resin matrix include styrene-based or acrylic polymers. The styrenic or acrylic polymer as the resin matrix is not limited, and for example, a resin matrix used in a known anion exchange resin can be used. The resin matrix of the anion exchange resin B is preferably styrene, from the viewpoint of the removal efficiency of the fluorine-containing compound.

The anion exchange resin B may be either weakly basic or strongly basic. Strongly basic anion exchange resins are preferred.

The basicity of the anion exchange resin B can be variously set depending on the kind of the polymer backbone and/or the ion exchange group.

The pore diameter of the anion exchange resin B is preferably set to be the same as that of the anion exchange resin BFrom the viewpoint of removal efficiency, the pore diameter is preferably set to be smallAbove, more preferablyThe above is more preferableThe above. In addition, can beAs above, the above may be The above. In addition, the pore diameter may beThe following. The pore diameter can be calculated by measuring the specific surface area and the total pore volume by a gas adsorption method, for example.

From the viewpoint of removal efficiency, the total exchange capacity of the anion exchange resin B is preferably 0.1 eq/L-resin or more. More preferably 0.3 eq/L-resin or more, still more preferably 0.5 eq/L-resin or more, and particularly preferably 0.7 eq/L-resin or more. The larger the total exchange capacity, the better, but for example, the upper limit is preferably 5.0 eq/L-resin, more preferably 2.0 eq/L-resin or less, and particularly preferably 1.5 eq/L-resin or less.

The water content of the anion exchange resin B is preferably 20% by mass or more, more preferably 30 to 70% by mass, and further preferably 35 to 65% by mass. By setting the moisture content of the anion exchange resin B to 30% by mass or more, the fluorine-containing compound can be efficiently removed. Further, the fluorine-containing compound is easily diffused into the particles of the anion exchange resin B. When the moisture content of the anion exchange resin B is 70% by mass or less, the decrease in the particle strength of the anion exchange resin B due to insufficient crosslinking can be suppressed.

The moisture content can be measured by the same method as that for the anion exchange resin a.

The anion exchange resin B is usually spherical. The average particle diameter of the anion exchange resin B is preferably 0.1 to 5mm, more preferably 0.2 to 2mm, and particularly preferably 0.3 to 1.5 mm. When the average particle diameter of the anion exchange resin B is within the above range, the packed column of the anion exchange resin is less likely to be clogged. The average particle diameter is a value obtained by a sieving method. Specifically, first, the anion exchange resin B was taken into a sieve shaker, and the particle size distribution was measured by sieving. Then, the diameter of the mesh corresponding to 50% of the residual classifier was obtained and used as the average particle diameter.

As the anion exchange resin B, commercially available products can be used, and examples thereof include Diaion (trademark) SA series manufactured by Mitsubishi chemical corporation, Amberlite (trademark) series manufactured by DuPont, such as A400 and A300 manufactured by Purolite corporation, and Amberjet (trademark) series such as IRA4002 OH.

The step B may be carried out before the step A or after the step A, and is preferably carried out before the step A because the removal efficiency of the fluorine-containing compound is improved.

The production process of the present invention preferably comprises a step B of bringing an aqueous fluoropolymer dispersion obtained from a hydrocarbon surfactant into contact with an anion exchange resin B, and a step A of bringing an aqueous fluoropolymer dispersion obtained after the step B into contact with an anion exchange resin A or a synthetic adsorbent.

The temperature in the step B is not limited, and may be, for example, 0 to 50 ℃. From the viewpoint of improving the removal efficiency, it is preferably 5 ℃ or higher. Further, it is preferably 40 ℃ or lower, more preferably 35 ℃ or lower. Further, the temperature may be 20 ℃ or lower.

The pressure in the step B is not particularly limited, and may be, for example, 0.1 to 10 atmospheres, and may be carried out under normal pressure (about 1 atmosphere).

The contact time in the step B is not particularly limited, and may be 0.1 second to 100 hours, 1 second to 50 hours, or 1 second to 10 hours. Further, the time may be 1 second to 1 hour.

The contact in the step B may be a batch type or a flow type. The step B may be performed 1 time or repeated 2 or more times.

In the step B, the amount of the anion exchange resin B to the aqueous fluoropolymer dispersion is not limited, and may be, for example, 0.01 to 1000g per 1000g of the aqueous fluoropolymer dispersion. The amount of the aqueous fluoropolymer dispersion is preferably 0.1g or more, more preferably 1g or more, and still more preferably 5g or more, per 1000g of the aqueous fluoropolymer dispersion. Further, it is preferably 500g or less.

The method for bringing the aqueous fluoropolymer dispersion into contact with the anion exchange resin B may be a method conventionally used, and the method described in the step a may be suitably used. For example, a method of adding the anion exchange resin B to the aqueous fluoropolymer dispersion and stirring the mixture can be mentioned.

When a method of adding the anion exchange resin B to the aqueous fluoropolymer dispersion and stirring the mixture is used, it is preferable to separate the anion exchange resin B from the aqueous fluoropolymer dispersion after the step B in the step B after bringing the aqueous fluoropolymer dispersion into contact with the anion exchange resin B. The method for separating the anion exchange resin B from the aqueous fluoropolymer dispersion is not limited, and for example, filtration or the like may be used. The step B may be a step of recovering the anion exchange resin B after bringing the aqueous fluoropolymer dispersion into contact with the anion exchange resin B.

The anion exchange resins a and B and the synthetic adsorbent used in the steps a and B may be reused by eluting the adsorbed fluorine-containing compound by treatment with an alkali solution containing water and an organic solvent. As the base, hydroxide of an alkali metal such as NaOH or KOH, or NH may be used₄OH and the like. Further, the eluted fluorine-containing compound can be recovered.

The production method of the present invention preferably includes a step of adding a nonionic surfactant to the aqueous fluoropolymer dispersion before step a. The aqueous fluoropolymer dispersion obtained using the hydrocarbon surfactant usually contains the hydrocarbon surfactant, but the amount of the hydrocarbon surfactant may be reduced in the step a, and the stability of the aqueous dispersion may be reduced. By adding the nonionic surfactant before the step A, the stability of the aqueous fluoropolymer dispersion after the step A can be improved. The amount of the nonionic surfactant added is not particularly limited, and may be an amount capable of maintaining the stability of the aqueous fluoropolymer dispersion. For example, the content is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more, relative to the fluoropolymer contained in the aqueous fluoropolymer dispersion.

When the step B is performed before the step a, it is preferable to include a step of adding a nonionic surfactant to the aqueous fluoropolymer dispersion before the step B.

In the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, examples of the nonionic surfactant include those represented by the following general formula (i)

R⁶-O-A¹-H(i)

(in the formula, R⁶Is a linear or branched primary or secondary alkyl group having 8 to 18 carbon atoms, A¹Is a polyoxyalkylene chain. ) The compounds represented.

R⁶The number of carbon atoms of (A) is preferably 10 to 16, more preferably 12 to 16. R⁶When the number of carbon atoms of (2) is 18 or less, the aqueous dispersion liquid tends to have good dispersion stability. In addition, R⁶When the number of carbon atoms exceeds 18, the fluidity temperature is high, and the handling is difficult. R⁶When the number of carbon atoms of (2) is less than 8, the surface tension of the aqueous dispersion increases, and the permeability and wettability tend to decrease.

The polyoxyalkylene chain may be composed of an oxyethylene group and an oxypropylene group. The polyoxyalkylene chain is preferably a polyoxyalkylene chain composed of an oxyethylene group having an average repeating number of 5 to 20 and an oxypropylene group having an average repeating number of 0 to 2, and is a hydrophilic group. The oxyethylene unit number may comprise any of a broad or narrow monomodal distribution as commonly provided, or a broader distribution or a bimodal distribution obtained by blending. When the average repeating number of the oxypropylene group is greater than 0, the oxyethylene group and the oxypropylene group in the polyoxyalkylene chain may be arranged in a block form or may be arranged in a random form.

The polyoxyalkylene chain preferably has an average repeating number of 7 to 12 from the viewpoint of viscosity and stability of the aqueous dispersionA polyoxyalkylene chain comprising an oxyethylene group and an oxypropylene group having an average repetition number of 0 to 2. In particular in A¹The propylene oxide having an average propylene oxide content of 0.5 to 1.5 is preferable because low foaming properties are good.

More preferably, R⁶Is (R ') (R') HC-, wherein R 'and R' are the same or different linear, branched or cyclic alkyl groups, and the total number of carbon atoms is at least 5, preferably 7 to 17. Preferably, at least one of R 'or R' is a branched or cyclic hydrocarbon group.

Specific examples of the compound (polyoxyethylene alkyl ether) represented by the general formula (i) include C₁₃H₂₇-O-(C₂H₄O)₁₀-H、C₁₃H₂₇-O-(C₂H₄O)₈-H、C₁₂H₂₅-O-(C₂H₄O)₁₀-H、C₁₀H₂₁CH(CH₃)CH₂-O-(C₂H₄O)₉-H、C₁₃H₂₇-O-(C₂H₄O)₉-(CH(CH₃)CH₂O)-H、C₁₆H₃₃-O-(C₂H₄O)₁₀-H、HC(C₅H₁₁)(C₇H₁₅)-O-(C₂H₄O)₉-H, etc. Commercially available products of the compound (polyoxyethylene alkyl ether) represented by the general formula (i) include, for example, Genapol X080 (product name, manufactured by Clariant corporation), NOIGEN TDS series (first Industrial pharmaceutical Co., Ltd.) such as NOIGEN TDS-80 (product name), LEOCOL TD series (manufactured by LeOCOL Wang Gong Co., Ltd.) such as LEOCOL TD-90 (product name), LIONOL (registered trademark) TD series (manufactured by Leo Wang Gong Co., Ltd.), T-Det A series (manufactured by Harcross Chemicals) such as T-Det A138 (product name), and Tergitol (registered trademark) 15-S series (manufactured by Tao chemical Co., Ltd.).

The above nonionic surfactant is also preferably an ethoxylate of 2,6, 8-trimethyl-4-nonanol having an average of from about 4 to about 18 ethylene oxide units, an ethoxylate of 2,6, 8-trimethyl-4-nonanol having an average of from about 6 to about 12 ethylene oxide units, or a mixture thereof. Such nonionic surfactants are also commercially available as TERGITOL TMN-6, TERGITOL TMN-10 and TERGITOL TMN-100X (both product names, manufactured by the Dow chemical company).

In addition, the hydrophobic group of the nonionic surfactant may be any of an alkylphenol group, a straight-chain alkyl group, and a branched-chain alkyl group.

For example, examples of the polyoxyethylene ether alkylphenyl ether nonionic compound include those represented by the following general formula (ii)

R⁷-C₆H₄-O-A²-H(ii)

(in the formula, R⁷Is a linear or branched primary or secondary alkyl group having 4 to 12 carbon atoms, A²Is a polyoxyalkylene chain. ) The compounds shown. Specific examples of the polyoxyethylene ether alkylphenyl ether nonionic compound include TRITON (registered trademark) X-100 (trade name, manufactured by Dow chemical Co., Ltd.).

Examples of the nonionic surfactant include polyhydric alcohol compounds. Specifically, there are polyol compounds described in international publication No. 2011/014715, and the like.

As a typical example of the polyol compound, a compound having 1 or more sugar units as a polyol unit can be cited. The saccharide units may be modified to contain at least 1 long chain. Preferred polyol compounds containing at least 1 long chain moiety include, for example, alkyl glucosides, modified alkyl glucosides, sugar esters, and combinations thereof. Examples of the sugar include, but are not limited to, monosaccharide, oligosaccharide, and sorbitan. Examples of the monosaccharide include a five-carbon sugar and a six-carbon sugar. Typical examples of the monosaccharide include ribose, glucose, galactose, mannose, fructose, arabinose, and xylose. The oligosaccharide may be an oligomer of 2 to 10 identical or different monosaccharides. Examples of oligosaccharides include, but are not limited to, sucrose, maltose, lactose, raffinose, and isomaltose.

Typically, as the sugar suitable for use as the polyol compound, there may be mentioned a five-membered ring compound containing 4 carbon atoms and 1 hetero atom (typically oxygen or sulfur, preferably oxygen atom), or a six-membered ring compound containing 5 carbon atoms and the above-mentioned 1 hetero atom, preferably oxygen atom. These sugars further contain at least 2 or at least 3 hydroxyl groups (-OH groups) bonded to a carbon ring atom. Typically, sugars are modified in the following respects: more than 1 of the hydrogen atoms of the hydroxyl (and/or hydroxyalkyl) groups bonded to the carbon ring atoms are substituted with long chain residues to make ether or ester linkages between the long chain residues and the sugar moieties.

The sugar-based polyol may contain 1 sugar unit or 2 or more sugar units. 1 sugar unit or 2 or more sugar units may be modified in the above-mentioned long chain portion. Specific examples of the sugar-based polyol compound include glucoside, sugar ester, sorbitan ester, and mixtures and combinations thereof.

A preferred class of polyol compounds is alkyl glucosides or modified alkyl glucosides. These classes of surfactants contain at least 1 glucose moiety.

Can give

[ solution 1]

(wherein x represents 0, 1, 2, 3, 4 or 5, and R¹And R²Independently represents H or a long chain unit containing at least 6 carbon atoms, wherein R¹And R²At least 1 of which is not H). As R¹And R²As a typical example of (A), an aliphatic alcohol residue can be mentioned. Examples of the aliphatic alcohol include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), eicosanoic acid, and combinations thereof.

The above formula shows a specific example of an alkylpolyglucoside of glucose showing the pyranose form, but it will be appreciated that other sugars or sugars of different mirror image isomers or diastereoisomeric forms of the same sugar may also be used.

Alkyl glucosides can be obtained, for example, by acid-catalyzed reaction of glucose, starch or n-butyl glucoside with aliphatic alcohols, from which, in the typical case, mixtures of various alkyl glucosides are obtained (Alkylpolyglycylcoside, Rompp, Lexikon Chemie, Version 2.0, Stuttgart/New York, Georg Thieme Verlag, 1999). Examples of the aliphatic alcohol include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), eicosanoic acid, and combinations thereof. In addition, alkyl glucosides are commercially available from Cognis GmbH, Dusseldorf, Germany under the trade name GLUCOPON or DISPONIL.

Examples of the other nonionic surfactants include bifunctional block copolymers supplied by BASF as Pluronic (registered trademark) R series, tridecanol alkoxylates supplied by BASF as Iconol (registered trademark) TDA series, and hydrocarbon-containing silicone surfactants.

The nonionic surfactant is preferably a nonionic surfactant containing no aromatic moiety.

The production method of the present invention preferably includes a step of concentrating the aqueous fluoropolymer dispersion having undergone step a after step a.

Examples of the concentration method include phase separation concentration, ion exchanger method, membrane concentration, and the like. The phase separation concentration, the ion exchanger method and the membrane concentration can be carried out by conventionally known treatment conditions, and are not particularly limited, and can be carried out by methods described in the pamphlet of International publication No. 2004/050719, Japanese patent application laid-open No. 2002-532583 and Japanese patent application laid-open No. 55-120630.

Among the above-mentioned concentration methods, phase separation concentration is preferable. Phase separation concentration is usually performed by adding a nonionic surfactant. The production method of the present invention preferably further comprises a step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion after the step a to perform phase separation and concentration.

The above-mentioned phase separation concentration is carried out, for example, by the following manner: the aqueous dispersion to which the nonionic surfactant is added is heated to separate into a fluoropolymer-free phase (supernatant phase) and a fluoropolymer-containing phase (concentrated phase), and the fluoropolymer-free phase is removed to recover the fluoropolymer-containing phase.

The phase separation and concentration can be carried out by leaving the mixture at a temperature 10 ℃ or higher lower than the cloud point of the nonionic surfactant to be used. The phase separation and concentration may be performed by leaving the mixture at a temperature 10 ℃ or lower than the cloud point.

The nonionic surfactant used in the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, which is performed before the step B, can be used.

The nonionic surfactant is preferably a nonionic surfactant containing no aromatic moiety.

In the phase separation concentration, the amount of the nonionic surfactant added is not limited, and may be added in an amount of preferably 50% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less, based on 100% by mass of the fluoropolymer. The amount of the above-mentioned additive may be in the above-mentioned range, and for example, may be 0.1% by mass or more based on 100% by mass of the fluoropolymer.

In the production method of the present invention, the step C is preferably performed 2 or more times. The step C is more preferably carried out 3 times or more. The upper limit of the number of times is not limited, and may be, for example, 10 times or less.

When the step C is carried out 2 or more times, the phase separation and concentration in the step C1 is preferably carried out by heating at a temperature 5 ℃ or more lower than the cloud point of the nonionic surfactant, then leaving the mixture to stand, and separating the mixture into a supernatant phase and a concentrated phase. The heating temperature is more preferably 3 ℃ or higher lower than the cloud point, still more preferably at least the cloud point, and particularly preferably at a temperature exceeding the cloud point.

In addition, in the phase separation and concentration in the 2 nd or subsequent step C, it is preferable that the mixture is heated at a temperature 5 ℃ or higher than the cloud point of the nonionic surfactant and then allowed to stand to separate into a supernatant phase and a concentrated phase. The heating temperature is more preferably 3 ℃ or higher lower than the cloud point, and particularly preferably up to the cloud point.

The production process of the present invention can efficiently remove the following fluorine-containing compound from the aqueous fluoropolymer dispersion to obtain a purified aqueous fluoropolymer dispersion in which the amount of the following fluorine-containing compound is reduced. The aqueous fluoropolymer dispersion to be treated preferably contains a fluorine-containing compound represented by the following general formula (1) or (2).

General formula (1): (H- (CF)₂)_m-COO)_pM¹

(wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

General formula (2): (H- (CF)₂)_n-SO₃)_qM²

(wherein n is 4 to 20. M)²Is H, a metal atom, NR⁵ ₄(R⁵The same as above), imidazolium with or without a substituent, pyridinium with or without a substituent, or phosphonium with or without a substituent. q is 1 or 2. )

Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1) and an alkaline earth metal (group 2), and specifically, Na, K, Li, and the like.

As the above-mentioned R⁵4 of R⁵May be the same or different. As R⁵The organic group may be H or an organic group having 1 to 10 carbon atoms, and may be H or an organic group having 1 to 4 carbon atoms. In one embodiment, the alkyl group has 1 to 10 carbon atoms and 1 to 4 carbon atoms. All of R described below⁵The above-mentioned specifications can be applied.

In the general formula (1), m may be 5 to 11.

In the general formula (2), n may be 6 to 12.

The aqueous fluoropolymer dispersion may contain the fluorine-containing compound represented by the general formula (1) but not the fluorine-containing compound represented by the general formula (2), may contain the fluorine-containing compound represented by the general formula (2) but not the fluorine-containing compound represented by the general formula (1), or may contain both the fluorine-containing compound represented by the general formula (1) and the fluorine-containing compound represented by the general formula (2).

The fluorine-containing compound may include 2 or more kinds of the fluorine-containing compounds represented by the general formula (1), may include 2 or more kinds of the fluorine-containing compounds represented by the general formula (2), and may include 2 or more kinds of the compounds represented by the general formula (1) and 2 or more kinds of the fluorine-containing compounds represented by the general formula (2), and is not limited.

For example, there may be mentioned an embodiment comprising a fluorine-containing compound of the general formula (1) wherein m is 6 and a fluorine-containing compound of the general formula (12), an embodiment comprising a fluorine-containing compound of the general formula (2) wherein n is 6 and a fluorine-containing compound of the general formula (12), and the like. The fluorine-containing compound represented by the general formula (1) and the compound represented by the general formula (2) may contain 2 or more species, 3 or more species, or 4 or more species, as long as they contain at least 1 species.

In the fluorine-containing compounds contained in the general formula (1), the fluorine-containing compounds in which m is 3, 5, 7, 9, 11, 13, 15, 17, and 19 may be contained instead of the fluorine-containing compounds in which m is 4, 6, 8, 10, 12, 14, 16, and 18, the fluorine-containing compounds in which m is 4, 6, 8, 10, 12, 14, 16, 18, and 20 may be contained instead of the fluorine-containing compounds in which m is 3, 5, 7, 9, 11, 13, 15, 17, and 19, or all the fluorine-containing compounds in which m is 3 to 19 may be contained.

In the fluorine-containing compounds contained in the general formula (2), the fluorine-containing compounds in which n is 5, 7, 9, 11, 13, 15, 17 or 19 may be contained without the fluorine-containing compounds in which n is 4, 6, 8, 10, 12, 14, 16, 18 or 20, the fluorine-containing compounds in which n is 4, 6, 8, 10, 12, 14, 16, 18 or 20 may be contained without the fluorine-containing compounds in which n is 5, 7, 9, 11, 13, 15, 17 or 19, or all the fluorine-containing compounds in which n is 4 to 20 may be contained.

In the production method of the present invention, the concentration of the fluorine-containing compound represented by the general formula (1) or (2) in the aqueous fluoropolymer dispersion to be treated is not particularly limited, and any concentration of the aqueous fluoropolymer dispersion may be treated.

The total content of the compounds represented by the above general formulae (1) and (2) in the aqueous fluoropolymer dispersion to be treated is more than 1ppm, may be 2ppm or more, may be 5ppm or more, may be 10ppm or more, and may be 50ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (1) or (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

In addition, the total content of the fluorine-containing compounds represented by the general formulae (1) and (2) in the aqueous fluoropolymer dispersion to be treated may be 30000ppm or less, may be 10000ppm or less, may be 5000ppm or less, may be 2000ppm or less, may be 1000ppm or less, may be 500ppm or less, and may be 200ppm or less, relative to the fluoropolymer. By setting the total amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved. The total content is the sum of the content of all fluorine-containing compounds contained in the general formula (1) and the content of all fluorine-containing compounds contained in the general formula (2).

The aqueous fluoropolymer dispersion may be an aqueous fluoropolymer dispersion obtained by polymerizing a fluoropolymer as it is, or may be an aqueous fluoropolymer dispersion obtained by diluting or concentrating an aqueous fluoropolymer dispersion produced by polymerizing a fluoropolymer so that the total amount of the fluorine-containing compounds represented by the general formulae (1) and (2) falls within the above range.

In the present specification, ppm is a value obtained in terms of mass unless otherwise specified.

The amount of at least 1 kind of fluorine-containing compounds of the above general formula (1) wherein m is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19 may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, more than 1ppm, 5ppm or more, and 10ppm or more, respectively, relative to the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of at least 1 kind of fluorine-containing compounds of the above general formula (1) wherein m is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19 may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less, respectively, relative to the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 3 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 3 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m 4 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 4 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, and 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 5 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 5 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 6 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 6 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 7 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 7 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 8 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 8 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 9 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 9 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 10 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 10 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 11 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 11 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 12 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 12 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m 13 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 13 m in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 14 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 14 m in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 15 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 15 m in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 16 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 16 m in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 17 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 17 m in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 18 in the above general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 18 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having m of 19 in the general formula (1) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer.

When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having m of 19 in the general formula (1) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of at least 1 kind of fluorine-containing compounds of the general formula (2) wherein n is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, or 10ppm or more, respectively, relative to the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of at least 1 kind of fluorine-containing compounds of the general formula (2) wherein n is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less, respectively, relative to the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 4 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 4 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 5 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 5 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 6 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 6 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 7 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 7 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 8 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 8 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 9 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 9 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 10 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 10 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 11 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 11 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 12 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 12 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 13 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 13 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 14 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 14 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having 15 n in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 15 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having 16 n in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 16 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 17 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 17 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 18 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 18 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 19 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having n of 19 in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The amount of the fluorine-containing compound having n of 20 in the general formula (2) may be 0.01ppm or more, 0.1ppm or more, 0.5ppm or more, 1ppm or more, 5ppm or more, and 10ppm or more based on the fluoropolymer. When the concentration of the fluorine-containing compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is not less than the predetermined concentration as described above, higher removal efficiency can be exhibited.

The amount of the fluorine-containing compound having 20 n in the general formula (2) may be 10000ppm or less, 5000ppm or less, 2000ppm or less, 1000ppm or less, 500ppm or less, or 200ppm or less based on the fluoropolymer. When the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion is in the above range, the removal efficiency can be further improved.

The aqueous fluoropolymer dispersion preferably contains at least a fluorine-containing compound having m of 7 or more in the general formula (1) or a fluorine-containing compound having n of 8 or more in the general formula (2).

The aqueous fluoropolymer dispersion preferably contains a fluorine-containing compound of the general formula (1) in which m is 9 or more or a fluorine-containing compound of the general formula (2) in which n is 10 or more, and more preferably contains a fluorine-containing compound of the general formula (1) in which m is 11 or more or a fluorine-containing compound of the general formula (2) in which n is 12 or more.

The aqueous fluoropolymer dispersion preferably contains a compound represented by the general formula (1). The production method of the present invention is particularly effective when the compound represented by the general formula (1) is contained. In particular, it is effective when the fluorine-containing compound of the general formula (1) in which m is 7 or more, more preferably 9 or more, and still more preferably 11 or more is contained.

In the aqueous fluoropolymer dispersion, the concentration of the fluoropolymer in the aqueous fluoropolymer dispersion is 10 to 90% by mass. The lower limit of the concentration of the fluoropolymer is preferably 15% by mass, the higher limit thereof is preferably 20% by mass, the higher limit thereof is preferably 80% by mass, and the higher limit thereof is preferably 70% by mass.

The aqueous fluoropolymer dispersion generally contains an aqueous medium such as water. In the present specification, the term "aqueous medium" refers to water and a mixed medium containing water and a water-soluble organic solvent (for example, alcohols such as methanol, ethanol, and propanol, esters such as methyl acetate, ketones such as acetone, and ethers such as dimethyl ether).

The aqueous fluoropolymer dispersion may have a pH of, for example, 1.5 to 13.5, and may have a pH of 2 to 13, and is not particularly limited. For example, the aqueous fluoropolymer dispersion in the steps A and B may have a pH of 2 to 12, or 2 to 11.

As a method for adjusting the pH of the aqueous fluoropolymer dispersion, a method of adjusting the pH by adding an acid or a base before the step a or the step B can be mentioned.

For example, when the step B and the step a are performed in this order, the pH of the aqueous fluoropolymer dispersion in the step B may be acidic, and the aqueous fluoropolymer dispersion to be supplied to the step a may be basic.

The aqueous fluoropolymer dispersion containing the fluorine-containing compound represented by the general formula (1) or the general formula (2) can be obtained by polymerization using a hydrocarbon surfactant.

The aqueous fluoropolymer dispersion is obtained by using a hydrocarbon surfactant. More specifically, the aqueous fluoropolymer dispersion is preferably obtained by polymerizing a fluoromonomer in an aqueous medium in the presence of a hydrocarbon surfactant.

The production method of the present invention preferably further comprises a step of polymerizing a fluoromonomer in an aqueous medium in the presence of a hydrocarbon surfactant to obtain an aqueous fluoropolymer dispersion.

As the above-mentioned fluoromonomer, a fluoromonomer having at least 1 double bond is preferable.

The fluorine monomer is preferably selected from the group consisting of tetrafluoroethylene [ TFE ]]Hexafluoropropylene [ HFP ]]Chlorotrifluoroethylene [ CTFE ]]Vinyl fluoride, vinylidene fluoride [ VDF ]]Trifluoroethylene, fluoroalkyl vinyl ether, fluoroalkyl ethylene, fluoroalkyl allyl ether, trifluoropropene, pentafluoropropene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, general formula (100): CHX¹⁰¹＝CX¹⁰²Rf¹⁰¹(in the formula, X¹⁰¹And X¹⁰²One of them is H, the other is F, Rf¹⁰¹A linear or branched fluoroalkyl group having 1 to 12 carbon atoms), a fluorinated vinyl heterocyclic compound, and a monomer providing a crosslinking site.

The fluoroalkyl vinyl ether is preferably selected from the group consisting of

General formula (110): CF (compact flash)₂＝CF-ORf¹¹¹

(wherein Rf¹¹¹Represents a perfluoroorganic group. ) The fluorine monomer represented by,

General formula (120): CF (compact flash)₂＝CF-OCH₂-Rf¹²¹

(wherein Rf¹²¹A perfluoroalkyl group having 1 to 5 carbon atoms) and a polymerization initiator,

General formula (130): CF (compact flash)₂＝CFOCF₂ORf¹³¹

(wherein Rf¹³¹The perfluoroalkyl group is a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, or a linear or branched perfluorooxyalkyl group having 1 to 3 oxygen atoms and having 2 to 6 carbon atoms. ) The fluorine monomer represented by,

General formula (140): CF (compact flash)₂＝CFO(CF₂CF(Y¹⁴¹)O)_m(CF₂)_nF

(in the formula, Y¹⁴¹Represents a fluorine atom or a trifluoromethyl group. m is an integer of 1 to 4. n is an integer of 1 to 4. ) Fluoromonomers represented by the formula and

general formula (150): CF (compact flash)₂＝CF-O-(CF₂CFY¹⁵¹-O)_n-(CFY¹⁵²)_m-A¹⁵¹

(in the formula, Y¹⁵¹Represents a fluorine atom, a chlorine atom or-SO₂F groups or perfluoroalkyl groups. The perfluoroalkyl group may contain etheric oxygen and-SO₂And F group. n represents an integer of 0 to 3. n number of Y¹⁵¹May be the same or different. Y is¹⁵²Represents a fluorine atom, a chlorine atom or-SO₂And F group. m represents an integer of 1 to 5. m number of Y¹⁵²May be the same or different. A. the¹⁵¹represents-SO₂X¹⁵¹、-COZ¹⁵¹or-POZ¹⁵²Z¹⁵³。X¹⁵¹Represents F, Cl, Br, I, -OR¹⁵¹or-NR¹⁵²R¹⁵³。Z¹⁵¹、Z¹⁵²And Z¹⁵³Identically or differently representing-NR¹⁵⁴R¹⁵⁵OR-OR¹⁵⁶。R¹⁵¹、R¹⁵²、R¹⁵³、R¹⁵⁴、R¹⁵⁵And R¹⁵⁶The same or different represents H, ammonium, an alkali metal, an alkyl group which may or may not contain a fluorine atom, an aryl group or a sulfonyl group-containing group. ) The fluorine monomer

At least 1 of the group consisting of.

In the present specification, the "perfluoro organic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced with fluorine atoms. The perfluoro organic group may have an etheric oxygen.

Rf is an example of the fluorine monomer represented by the general formula (110)¹¹¹A fluorine monomer which is a perfluoroalkyl group having 1 to 10 carbon atoms. The perfluoroalkyl group preferably has 1 to 5 carbon atoms.

Examples of the perfluoroorganic group in the general formula (110) include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

The fluoromonomer represented by the general formula (110) may further include Rf in the general formula (110)¹¹¹Fluorine monomer which is C4-9 perfluoro (alkoxyalkyl), Rf¹¹¹Is of the formula:

[ solution 2]

(wherein m represents 0 or an integer of 1 to 4.) a group represented by¹¹¹Is of the formula:

[ solution 3]

(wherein n represents an integer of 1 to 4.) and the like.

As the fluoromonomer represented by the general formula (110), among them, preferred is

General formula (160): CF (compact flash)₂＝CF-ORf¹⁶¹

(wherein Rf¹⁶¹Represents a perfluoroalkyl group having 1 to 10 carbon atoms. ) The fluoromonomer is shown. Rf¹⁶¹Preferably a perfluoroalkyl group having 1 to 5 carbon atoms.

The fluoroalkyl vinyl ether is preferably at least 1 selected from the group consisting of fluorine monomers represented by general formulae (160), (130), and (140).

The fluoromonomer represented by general formula (160) is preferably at least 1 selected from the group consisting of perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), and perfluoro (propyl vinyl ether), and more preferably at least 1 selected from the group consisting of perfluoro (methyl vinyl ether) and perfluoro (propyl vinyl ether).

The fluorine monomer represented by the general formula (130) is preferably selected from the group consisting of CF₂＝CFOCF₂OCF₃、CF₂＝CFOCF₂OCF₂CF₃And CF₂＝CFOCF₂OCF₂CF₂OCF₃At least 1 of the group consisting of.

The fluorine monomer represented by the general formula (140) is preferably selected from the group consisting of CF₂＝CFOCF₂CF(CF₃)O(CF₂)₃F、CF₂＝CFO(CF₂CF(CF₃)O)₂(CF₂)₃F and CF₂＝CFO(CF₂CF(CF₃)O)₂(CF₂)₂F, at least 1 of the group.

The fluorine monomer represented by the general formula (150) is preferably selected from the group consisting of CF₂＝CFOCF₂CF₂SO₂F、CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂SO₂F、CF₂＝CFOCF₂CF(CF₂CF₂SO₂F)OCF₂CF₂SO₂F and CF₂＝CFOCF₂CF(SO₂F)₂At least 1 of the group consisting of.

As the fluorine monomer represented by the general formula (100), Rf is preferable¹⁰¹Fluoromonomers which are linear fluoroalkyl groups, more preferably Rf¹⁰¹A fluoromonomer that is a linear perfluoroalkyl group. Rf¹⁰¹The number of carbon atoms of (C) is preferably 1 to 6. Examples of the fluoromonomer represented by the general formula (100) include CH₂＝CFCF₃、CH₂＝CFCF₂CF₃、CH₂＝CFCF₂CF₂CF₃、CH₂＝CFCF₂CF₂CF₂H、CH₂＝CFCF₂CF₂CF₂CF₃、CHF＝CHCF₃(E-form), CHF ═ CHCF₃(Z form), etc., wherein CH is preferred₂＝CFCF₃2,3,3, 3-tetrafluoropropene is shown.

As the fluoroalkylethylene, preferred is

General formula (170): CH (CH)₂＝CH-(CF₂)_n-X¹⁷¹

(in the formula, X¹⁷¹Is H or F, and n is an integer of 3-10. ) The fluoroalkyl vinyl is more preferably selected from the group consisting of CH₂＝CH-C₄F₉And CH₂＝CH-C₆F₁₃At least 1 of the group consisting of.

Examples of the fluoroalkyl allyl ether include

General formula (180): CF (compact flash)₂＝CF-CF₂-ORf¹¹¹

(wherein Rf¹¹¹Represents a perfluoroorganic group. ) The fluoromonomer is shown.

Rf of the formula (180)¹¹¹And Rf of the formula (110)¹¹¹The same is true. As Rf¹¹¹Preferably a C1-10 perfluoroalkyl group or a C1-10 perfluoroalkoxyalkyl group. The fluoroalkyl allyl ether represented by the general formula (180) is preferably selected from the group consisting of CF₂＝CF-CF₂-O-CF₃、CF₂＝CF-CF₂-O-C₂F₅、CF₂＝CF-CF₂-O-C₃F₇And CF₂＝CF-CF₂-O-C₄F₉At least 1 of the group consisting of CF, more preferably CF₂＝CF-CF₂-O-C₂F₅、CF₂＝CF-CF₂-O-C₃F₇And CF₂＝CF-CF₂-O-C₄F₉At least 1 of the group consisting of, more preferably CF₂＝CF-CF₂-O-CF₂CF₂CF₃。

Examples of the fluorinated vinyl heterocyclic compound include compounds represented by the general formula (230):

[ solution 4]

(in the formula, X²³¹And X²³²Independently F, Cl, methoxy or fluoromethoxy, Y²³¹Is of the formula Y²³²Or formula Y²³³。

[ solution 5]

FC＝CF(Y²³2)

(in the formula, Z²³¹And Z²³²Independently F or a fluorinated alkyl group having 1 to 3 carbon atoms. ) Fluorinated vinyl heterocycles).

As the monomer providing the crosslinking site, it is preferably selected from the group consisting of

General formula (180): CX¹⁸¹ ₂＝CX¹⁸²-R_f ¹⁸¹CHR¹⁸¹X¹⁸³

(in the formula, X¹⁸¹And X¹⁸²Independently a hydrogen atom, a fluorine atom or CH ₃，R_f ¹⁸¹Is a fluoroalkylene, perfluoroalkylene, fluoro (poly) oxyalkylene or perfluoro (poly) oxyalkylene radical, R¹⁸¹Is a hydrogen atom or CH₃，X¹⁸³Is an iodine atom or a bromine atom. ) The fluorine monomer represented by,

General formula (190): CX¹⁹¹ ₂＝CX¹⁹²-R_f ¹⁹¹X¹⁹³

(in the formula, X¹⁹¹And X¹⁹²Independently of one another, a hydrogen atom, a fluorine atomSon or CH₃，R_f ¹⁹¹Is a fluoroalkylene, perfluoroalkylene, fluoropolyoxyalkylene or perfluoropolyoxyalkylene radical, X¹⁹³Is an iodine atom or a bromine atom. ) The fluorine monomer represented by,

General formula (200): CF (compact flash)₂＝CFO(CF₂CF(CF₃)O)_m(CF₂)_n-X²⁰¹

(wherein m is an integer of 0 to 5, n is an integer of 1 to 3, and X is²⁰¹Is cyano, carboxyl, alkoxycarbonyl, an iodine atom, a bromine atom or-CH₂I. ) Fluoromonomers represented by the formula and

general formula (210): CH (CH)₂＝CFCF₂O(CF(CF₃)CF₂O)_m(CF(CF₃))_n-X²¹¹

(wherein m is an integer of 0 to 5, n is an integer of 1 to 3, and X is²¹¹Is cyano, carboxyl, alkoxycarbonyl, an iodine atom, a bromine atom or-CH₂And (5) OH. ) Fluoromonomers represented by the formula and

general formula (220): CR²²¹R²²²＝CR²²³-Z²²¹-CR²²⁴＝CR²²⁵R²²⁶

(in the formula, R²²¹、R²²²、R²²³、R²²⁴、R²²⁵And R²²⁶The same or different are hydrogen atoms or alkyl groups having 1 to 5 carbon atoms. Z²²¹Is a linear or branched C1-18 alkylene group with or without oxygen atom, a C3-18 cycloalkylene group, an at least partially fluorinated C1-10 alkylene or oxyalkylene group, or

-(Q)_p-CF₂O-(CF₂CF₂O)_m(CF₂O)_n-CF₂-(Q)_p-

(wherein Q is an alkylene group or oxyalkylene group, p is 0 or 1. m/n is 0.2 to 5.) and a (per) fluoropolyoxyalkylene group having a molecular weight of 500 to 10000. ) The monomer represented

At least 1 of the group consisting of.

X¹⁸³And X¹⁹³Preferably an iodine atom. R_f ¹⁸¹And R_f ¹⁹¹Preferably a C1-5 perfluoroalkylene group. R¹⁸¹Preferably a hydrogen atom. X²⁰¹Preferably a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom or-CH₂I。X²¹¹Preferably a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom or-CH₂OH。

As the monomer providing the crosslinking site, it is preferably selected from the group consisting of CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂CN、CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOH、CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂CH₂I、CF₂＝CFOCF₂CF₂CH₂I、CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃)CN、CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃)COOH、CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃)CH₂OH、CH₂＝CHCF₂CF₂I、CH₂＝CH(CF₂)₂CH＝CH₂、CH₂＝CH(CF₂)₆CH＝CH₂And CF₂＝CFO(CF₂)₅CN, more preferably selected from the group consisting of CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂CN and CF₂＝CFOCF₂CF₂CH₂I, at least 1 of the group consisting of I.

In the above polymerization, the fluorine-containing monomer and the non-fluorine-containing monomer may be polymerized. Examples of the non-fluorine-containing monomer include hydrocarbon monomers reactive with the fluorine monomer. Examples of the hydrocarbon monomer include olefins such as ethylene, propylene, butylene, and isobutylene; alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, and cyclohexyl vinyl ether; vinyl esters such as vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl valerate, vinyl pivalate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl neodecanoate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl benzoate, vinyl p-tert-butylbenzoate, vinyl cyclohexanecarboxylate, vinyl monochloroacetate, vinyl adipate, vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl cinnamate, vinyl undecylenate, vinyl hydroxyacetate, vinyl hydroxypropionate, vinyl hydroxybutyrate, vinyl hydroxyvalerate, vinyl hydroxyisobutyrate, and vinyl hydroxycyclohexanecarboxylate; alkylallyl ethers such as ethylallyl ether, propylallyl ether, butylallyl ether, isobutylallyl ether, and cyclohexylallyl ether; and alkylallyl esters such as ethylallyl ester, propylallyl ester, butylallyl ester, isobutylallyl ester, and cyclohexylallyl ester.

The non-fluorine-containing monomer may be a hydrocarbon-based monomer having a functional group (excluding a monomer for providing a crosslinking site). Examples of the functional group-containing hydrocarbon monomer include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyisobutyl vinyl ether and hydroxycyclohexyl vinyl ether; non-fluorine-containing monomers having a carboxyl group such as itaconic acid, succinic anhydride, fumaric acid, fumaric anhydride, crotonic acid, maleic anhydride, and perfluorocrotonic acid; non-fluorine-containing monomers having a glycidyl group such as glycidyl vinyl ether and glycidyl allyl ether; non-fluorine-containing monomers having an amino group such as aminoalkyl vinyl ether and aminoalkyl allyl ether; and non-fluorine-containing monomers having an amide group such as (meth) acrylamide and methylolacrylamide.

In the above polymerization, by polymerizing 1 or 2 or more kinds of the above fluoromonomers, an aqueous dispersion of particles containing a desired fluoropolymer (aqueous fluoropolymer dispersion) can be obtained.

The above polymerization is also preferably carried out in the presence of a nonionic surfactant. The nonionic surfactant is preferably selected from

General formula (240): rf²⁴¹-(X²⁴¹)_n-Y²⁴¹

(wherein Rf²⁴¹Is a partially fluorinated alkyl group or a fully fluorinated alkyl group having 1 to 12 carbon atoms, n is 0 or 1, X²⁴¹is-O-, -COO-or-OCO-, Y²⁴¹Is- (CH)₂)_pH、-(CH₂)_pOH OR- (OR)²⁴¹)_q(OR²⁴²)_rOH, p is an integer of 1 to 12, q is an integer of 1 to 12, R is an integer of 0 to 12, R²⁴¹And R²⁴²Is an alkylene group having 2 to 4 carbon atoms. Wherein R is²⁴¹And R²⁴²Are different from each other. ) A compound represented by,

General formula (250): h (OR)²⁵¹)_u(OR²⁵²)_vOH

(in the formula, R²⁵¹And R²⁵²Is an alkylene group having 1 to 4 carbon atoms, and u and v are integers of 1 to 5. Wherein R is²⁵¹And R²⁵²Are different from each other. ) The block polymer represented by,

Nonionic polymer having in the molecule a hydrophobic group comprising a hydrocarbon group having 8 to 20 carbon atoms and a hydrophilic group comprising a polyalkylene oxide, and

general formula (260): r²⁶¹ _m-Si-(OR²⁶²)_4-m

(in the formula, R²⁶¹Is an alkyl group having 1 to 12 carbon atoms, R²⁶²Is an alkyl group having 1 to 4 carbon atoms, and m is an integer of 1 to 3. ) Silicon compound represented by

At least 1 of the group consisting of.

Specific examples of the block polymer represented by the general formula (250) include block polymers composed of at least 2 segments selected from the group consisting of polyoxyethylene, polyoxypropylene, and polyoxybutylene groups. Among them, polyoxyethylene-polyoxypropylene block polymers and polyoxyethylene-polyoxybutylene block polymers are exemplified, and a block polymer of not only a-B type but also a-B-a type is preferably exemplified. Further, it is preferable to use a polyoxyethylene-polyoxypropylene block polymer or a polyoxypropylene-polyoxyethylene-polyoxypropylene block polymer, whereby a stable fluoropolymer dispersion can be prepared at a high concentration. Further, when the polyoxyethylene segment content is 10 to 50%, it is considered that generation of flocs due to re-coagulation is small, and therefore, it is preferable, and further, when it is 20 to 40%, a low-viscosity fluoropolymer dispersion can be prepared, and therefore, it is preferable. The molecular weight is not particularly limited, and may be 1000 to 7000g/mol, and particularly 2500 to 6500g/mol, a dispersion having a low viscosity and excellent dispersibility can be prepared.

In the above polymerization, a nucleating agent may be used. The preferable amount of the nucleating agent is appropriately selected depending on the kind of the nucleating agent, and is, for example, 1000ppm or less, more preferably 500ppm or less, further preferably 100ppm or less, particularly preferably 50ppm or less, and particularly preferably 10ppm or less with respect to the aqueous medium.

By using the above nucleating agent, a fluoropolymer having a smaller primary particle size can be obtained than if the polymerization is carried out in the absence of the above nucleating agent.

Examples of the nucleating agent include dicarboxylic acids, perfluoropolyether (PFPE) acids or salts thereof, and hydrocarbon surfactants. The nucleating agent preferably does not contain an aromatic ring, and is preferably an aliphatic compound.

The nucleating agent is preferably added before or simultaneously with the addition of the polymerization initiator, but the particle size distribution may be adjusted by adding the nucleating agent during the polymerization.

The amount of the dicarboxylic acid is preferably 1000ppm or less, more preferably 500ppm or less, and still more preferably 100ppm or less, based on the aqueous medium.

The perfluoropolyether (PFPE) acid or a salt thereof may have any chain structure in which oxygen atoms in the main chain of the molecule are separated by saturated carbon fluoride groups having 1 to 3 carbon atoms. In addition, 2 or more kinds of carbon fluoride groups may be present in the molecule. Representative structures have repeating units represented by the formula:

(-CFCF₃-CF₂-O-)_n(VII)

(-CF₂-CF₂-CF₂-O-)_n(VIII)

(-CF₂-CF₂-O-)_n-(-CF₂-O-)_m(IX)

(-CF₂-CFCF₃-O-)_n-(-CF₂-O-)_m(X)

These structures are described by Kasai in j.appl.polymersci.57,797 (1995). As disclosed in this document, the above-mentioned PFPE acid or salt thereof may have a carboxylic acid group or salt thereof at one terminal or both terminals. The PFPE acid or a salt thereof may have a sulfonic acid group, a phosphonic acid group, or a salt thereof at one end or both ends. In addition, the above-mentioned PFPE acid or a salt thereof may have different groups at each terminal. For monofunctional PFPE, the other end of the molecule is typically perfluorinated, but may also contain a hydrogen or chlorine atom. The above-mentioned PFPE acid or a salt thereof has at least 2 etheric oxygens, preferably at least 4 etheric oxygens, and more preferably at least 6 etheric oxygens. Preferably at least 1 of the carbon fluoride groups separating the etheric oxygen, more preferably at least 2 of such carbon fluoride groups have 2 or 3 carbon atoms. Even more preferably, at least 50% of the carbon fluoride groups separating the etheric oxygen have 2 or 3 carbon atoms. In addition, the above-mentioned PFPE acid or salt thereof preferably has at least 15 carbon atoms in total, and for example, a preferred minimum value of n or n + m in the above-mentioned repeating unit structure is at least 5. The above-mentioned PFPE acid having 2 or more acid groups at one or both terminals or a salt thereof can be used in the production method of the present invention. The above-mentioned PFPE acid or salt thereof preferably has a number average molecular weight of less than 6000 g/mole.

The amount of the hydrocarbon surfactant used as the nucleating agent is preferably 40ppm or less, more preferably 30ppm or less, and still more preferably 20ppm or less, based on the aqueous medium. The amount in ppm of the lipophilic nucleation sites present in the aqueous medium is presumed to be less than the above-mentioned amount. Therefore, the amounts of the lipophilic nucleation sites are less than 50ppm, 40ppm, 30ppm and 20ppm, respectively, as described above. Since the lipophilic nucleation sites are thought to exist in molecular form, a large number of lipophilic nucleation sites can be formed even with a very small amount of the hydrocarbon-containing surfactant. Therefore, even if the hydrocarbon-containing surfactant is added to the aqueous medium only in an amount of about 1ppm, advantageous effects can be obtained. The lower limit is preferably 0.01ppm, more preferably 0.1 ppm.

The above-mentioned hydrocarbon surfactants include nonionic surfactants and cationic surfactants, and include silicone surfactants such as surfactants disclosed in U.S. Pat. No. 7,897,682 (Brothers et al) and U.S. Pat. No. 7,977,438 (Brothers et al).

The hydrocarbon surfactant is preferably a nonionic surfactant. That is, as the nucleating agent, a nonionic surfactant is preferable. The nonionic surfactant may not contain an aromatic moiety.

The nonionic surfactant used in the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, which is carried out before the step B, can be the nonionic surfactant described above.

In the above polymerization, in addition to the hydrocarbon surfactant and other compounds having surface active energy used as desired, additives may be used in order to stabilize the respective compounds. Examples of the additives include a buffer, a pH adjuster, a stabilizing aid, and a dispersion stabilizer.

The stabilizing aid is preferably paraffin, a fluorine-based oil, a fluorine-based solvent, silicone oil, or the like. The stabilizing aids may be used singly or in combination of 1 or more. As the stabilizing aid, paraffin wax is more preferable. The paraffin wax may be liquid, semisolid, or solid at room temperature, but is preferably a saturated hydrocarbon having 12 or more carbon atoms. The melting point of the paraffin wax is preferably 40 to 65 ℃ and more preferably 50 to 65 ℃.

The amount of the stabilizing aid used is preferably 0.1 to 12% by mass, more preferably 0.1 to 8% by mass, based on the mass of the aqueous medium used. The stabilizing aid is preferably sufficiently hydrophobic and is not a contaminant component because it is completely separated from an aqueous fluoropolymer dispersion such as an aqueous PTFE emulsion after emulsion polymerization of a fluoromonomer such as TFE.

The above polymerization was carried out as follows: the aqueous medium, the hydrocarbon surfactant, the monomer, and other additives as needed are charged into a polymerization reactor, the contents of the reactor are stirred while the reactor is maintained at a predetermined polymerization temperature, and then a predetermined amount of a polymerization initiator is added to initiate a polymerization reaction. After the polymerization reaction is started, a monomer, a polymerization initiator, a chain transfer agent, a hydrocarbon surfactant, and the like may be added additionally according to the purpose. The hydrocarbon surfactant may be added after the polymerization reaction is started.

In the above polymerization, the polymerization temperature is usually 5 to 120 ℃ and the polymerization pressure is usually 0.05 to 10 MPaG. The polymerization temperature and polymerization pressure are appropriately determined depending on the kind of the monomer to be used, the molecular weight of the target fluoropolymer, and the reaction rate.

For example, the polymerization temperature is more preferably 30 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is more preferably 120 ℃ or lower, and still more preferably 100 ℃ or lower.

The polymerization pressure is more preferably 0.3MPaG or more, still more preferably 0.5MPaG or more, and still more preferably 5.0MPaG or less, still more preferably 3.0MPaG or less. In particular, from the viewpoint of increasing the yield of the fluoropolymer, it is preferably 1.0MPaG or more, more preferably 1.2MPaG or more, still more preferably 1.5MPaG or more, and particularly preferably 2.0MPaG or more.

The hydrocarbon surfactant is preferably added in an amount of 0.0001 to 10% by mass based on 100% by mass of the aqueous medium in total. The lower limit is more preferably 0.001 mass%, and the upper limit is more preferably 1 mass%. When the amount is less than 0.0001% by mass, the dispersing power may be insufficient, and when it exceeds 10% by mass, the effect corresponding to the amount added may not be obtained, and the polymerization rate may be lowered or the reaction may be stopped. The amount of the compound to be added is appropriately determined depending on the kind of the monomer to be used, the molecular weight of the target fluoropolymer, and the like.

The polymerization is preferably carried out in the substantial absence of a fluorosurfactant.

In the present specification, "under the condition that the fluorosurfactant is substantially not present" means that the fluorosurfactant is 10ppm or less, preferably 1ppm or less, more preferably 100ppb or less, further preferably 10ppb or less, further more preferably 1ppb or less with respect to the aqueous medium.

Examples of the fluorinated surfactant include anionic fluorinated surfactants.

The anionic fluorosurfactant may be a surfactant containing fluorine atoms, for example, in which the total carbon number of the portion other than the anionic groups is 20 or less.

The above-mentioned fluorine-containing surfactant may be a surfactant containing fluorine having an anionic moiety with a molecular weight of 800 or less.

The "anionic moiety" refers to a moiety other than the cation of the above-mentioned fluorosurfactant. For example, F (CF) represented by the following formula (I)₂)_n1COOM is "F (CF)₂)_n1COO'.

The above-mentioned fluorosurfactant includes a fluorosurfactant having a LogPOW of 3.5 or less. The LogPOW is a partition coefficient between 1-octanol and water and is represented by LogP [ where P represents a ratio of a concentration of a fluorine-containing surfactant in octanol/a concentration of a fluorine-containing surfactant in water when a mixed solution of octanol/water (1: 1) containing a fluorine-containing surfactant is phase-separated ].

The LogPOW above is calculated as follows: in the column: TOSOHOODS-120T column (Manufactured by tokyo corporation), eluent: acetonitrile/0.6 mass% HClO₄Water 1/1 (vol/vol%), flow rate: 1.0 ml/min, sample size; 300. mu.L, column temperature: detection at 40 ℃ light: HPLC was performed under UV210nm conditions on standard substances (heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid) having known octanol/water partition coefficients, to prepare a standard curve of each dissolution time and the known octanol/water partition coefficient, and based on the standard curve LogPOW was calculated from the elution time of HPLC in the sample solution.

Specific examples of the above-mentioned fluorosurfactant include U.S. patent application publication No. 2007/0015864, U.S. patent application publication No. 2007/0015865, U.S. patent application publication No. 2007/0015866, U.S. patent application publication No. 2007/0276103, U.S. patent application publication No. 2007/0117914, U.S. patent application publication No. 2007/142541, U.S. patent application publication No. 2008/0015319, U.S. patent application publication No. 3250808, U.S. patent application publication No. 3271341, Japanese patent laid-open No. 2003-119204, International publication No. 2005/042593, International publication No. 2008/060461, International publication No. 2007/046377, International publication No. 2007/119526, International publication No. 2007/046482, International publication No. 2007/046345, And fluorosurfactants described in U.S. patent application publication No. 2014/0228531, international publication No. 2013/189824, and international publication No. 2013/189826.

Examples of the anionic fluorosurfactant include those represented by the following general formula (N)⁰)：

Xⁿ⁰-Rfⁿ⁰-Y⁰(N⁰)

(in the formula, X ⁿ⁰H, Cl or F. Rfⁿ⁰The alkylene group may contain 1 or more ether bonds and may have a C3-20 chain, branched or cyclic structure in which some or all of H is substituted with F, and some of H may be substituted with Cl. Y is⁰Is an anionic group. ) The compounds represented.

Y⁰The anionic group of (A) may be-COOM, -SO₂M or-SO₃M, which may be-COOM or-SO₃M。

M is H, a metal atom, NR⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁷Is H or an organic group.

Examples of the metal atom include alkali metals (group 1), alkaline earth metals (group 2), and the like, and examples thereof include Na, K, and Li.

As R⁷May be H or C_1-10The organic group of (A) may be H or C_1-4The organic group of (A) may be H or C_1-4Alkyl group of (1).

M may be H, a metal atom or NR⁷ ₄May be H, alkali metal (group 1), alkaline earth metal (group 2) or NR⁷ ₄May be H, Na, K, Li or NH₄。

Rf aboveⁿ⁰More than 50% of the H may be substituted by fluorine.

As the above general formula (N)⁰) Examples of the compounds include

The following general formula (N)¹)：

Xⁿ⁰-(CF₂)_m1-Y⁰(N¹)

(in the formula, Xⁿ⁰H, Cl and F, m1 is an integer of 3-15, Y⁰As defined above. ) A compound represented by the following general formula (N) ²)：

Rfⁿ¹-O-(CF(CF₃)CF₂O)_m2CFXⁿ¹-Y⁰(N²)

(wherein Rfⁿ¹Is a perfluoroalkyl group having 1 to 5 carbon atoms, m2 is an integer of 0 to 3, Xⁿ¹Is F or CF₃，Y⁰As defined above. ) A compound represented by the following general formula (N)³)：

Rfⁿ²(CH₂)_m3-(Rfⁿ³)_q-Y⁰(N³)

(wherein Rfⁿ²Is a partially or fully fluorinated alkyl group having 1 to 13 carbon atoms and containing an ether bond, m3 is an integer of 1 to 3, Rfⁿ³Is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, q is 0 or 1, Y⁰As defined above. ) A compound represented by the following general formula (N)⁴)：

Rfⁿ⁴-O-(CYⁿ¹Yⁿ²)_pCF₂-Y⁰(N⁴)

(wherein Rfⁿ⁴A linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms and containing an ether bond, Yⁿ¹And Yⁿ²Identically or differently H or F, p is 0 or 1, Y⁰As defined above. ) A compound represented by the formula (N)⁵)：

[ solution 6]

(in the formula, Xⁿ²、Xⁿ³And Xⁿ⁴H, F or a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms and containing an ether bond. Rfⁿ⁵Is a linear or branched partially or fully fluorinated alkylene group having 1 to 3 carbon atoms and containing an ether bond, L is a linking group, Y is⁰As defined above. Wherein, Xⁿ²、Xⁿ³、Xⁿ⁴And Rfⁿ⁵The total number of carbon atoms of (2) is 18 or less. ) The compounds represented.

As the above general formula (N)⁰) More specifically, the compound represented by the formula (I) includes a perfluorocarboxylic acid (I) represented by the following formula (I), an ω -H perfluorocarboxylic acid (II) represented by the following formula (II), a perfluoropolyether carboxylic acid (III) represented by the following formula (III), a perfluoroalkylalkylalkylene carboxylic acid (IV) represented by the following formula (IV), a perfluoroalkoxyfluorocarboxylic acid (V) represented by the following formula (V), a perfluoroalkylsulfonic acid (VI) represented by the following formula (VI), an ω -H perfluorosulfonic acid (VII) represented by the following formula (VII), a perfluoroalkylalkylalkylene sulfonic acid (VIII) represented by the following formula (VIII), an alkylalkylalkylene carboxylic acid (IX) represented by the following formula (IX), a fluorocarboxylic acid (X) represented by the following formula (X), an alkoxyfluorosulfonic acid (XI) represented by the following formula (XI), and a perfluoroalkylfluorosulfonic acid (VIII) represented by the following formula (XI), A compound (XII) represented by the following general formula (XII), a compound (XIII) represented by the following general formula (XIII), and the like.

The above-mentioned perfluorocarboxylic acid (I) is represented by the following general formula (I)

F(CF₂)_n1COOM (I)

(wherein n1 is an integer of 3 to 14, and M isH. Metal atom, NR⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁷Is H or an organic group. ) The indicated substances.

The omega-H perfluorocarboxylic acid (II) is represented by the following general formula (II)

H(CF₂)_n2COOM (II)

(wherein n2 is an integer of 4 to 15, and M is as defined above).

The above perfluoropolyether carboxylic acid (III) is represented by the following general formula (III)

Rf¹-O-(CF(CF₃)CF₂O)_n3CF(CF₃)COOM(III)

(wherein Rf¹Is a perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer of 0 to 3, and M is as defined above. ) The indicated substances.

The perfluoroalkyl alkylene carboxylic acid (IV) is represented by the following general formula (IV)

Rf²(CH₂)_n4Rf³COOM (IV)

(wherein Rf²Is a C1-5 perfluoroalkyl group, Rf³Is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, n4 is an integer of 1 to 3, and M is as defined above. ) The indicated substances.

The alkoxy fluorocarboxylic acid (V) is represented by the following general formula (V)

Rf⁴-O-CY¹Y²CF₂-COOM (V)

(wherein Rf⁴A linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms and containing an ether bond, Y¹And Y²Identically or differently, H or F, M being as defined above. ) The indicated substances.

The above perfluoroalkylsulfonic acid (VI) is represented by the following general formula (VI)

F(CF₂)_n5SO₃M (VI)

(wherein n5 is an integer of 3 to 14, and M is as defined above).

The omega-H perfluorosulfonic acid (VII) is represented by the following general formula (VII)

H(CF₂)_n6SO₃M (VII)

(wherein n6 is an integer of 4 to 14, and M is as defined above).

The above perfluoroalkyl alkylene sulfonic acid (VIII) is represented by the following general formula (VIII)

Rf⁵(CH₂)_n7SO₃M (VIII)

(wherein Rf⁵Is a perfluoroalkyl group having 1 to 13 carbon atoms, n7 is an integer of 1 to 3, and M is as defined above. ) The indicated substances.

The above-mentioned alkyl alkylene carboxylic acid (IX) is represented by the following general formula (IX)

Rf⁶(CH₂)_n8COOM (IX)

(wherein Rf⁶Is a linear or branched partially or fully fluorinated alkyl group having 1 to 13 carbon atoms and containing an ether bond, n8 is an integer of 1 to 3, and M is as defined above. ) The indicated substances.

The fluorocarboxylic acid (X) is represented by the following general formula (X)

Rf⁷-O-Rf⁸-O-CF₂-COOM (X)

(wherein Rf⁷Is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms and containing an ether bond, Rf⁸Is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and M is as defined above. ) The indicated substances.

The above alkoxy fluorosulfonic acid (XI) is represented by the following general formula (XI)

Rf⁹-O-CY¹Y²CF₂-SO₃M (XI)

(wherein Rf⁹A linear or branched C1-12 alkyl group which may contain an ether bond and may contain chlorine and may be partially or completely fluorinated, and Y ¹And Y²Identically or differently, H or F, M being as defined above. ) The indicated substances.

The above compound (XII) is represented by the following general formula (XII):

[ solution 7]

In the formula, X¹、X²And X³H, F are the same or different, and are a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms and containing an ether bond, Rf¹⁰Is C1-3 perfluoroalkylene, L is a linking group, Y⁰Is an anionic group. ) The indicated substances.

Y⁰Can be-COOM, -SO₂M or-SO₃M, may be-SO₃M or COOM (wherein M is as defined above).

Examples of L include a single bond, a partially or fully fluorinated alkylene group having 1 to 10 carbon atoms and containing an ether bond.

The above compound (XIII) is represented by the following general formula (XIII):

Rf¹¹-O-(CF₂CF(CF₃)O)_n9(CF₂O)_n10CF₂COOM (XIII)

(wherein Rf¹¹A C1-5 fluoroalkyl group containing chlorine, n9 is an integer of 0-3, n10 is an integer of 0-3, and M is as defined above. ) The indicated substances. As the compound (XIII), CF is mentioned₂ClO(CF₂CF(CF₃)O)_n9(CF₂O)_n10CF₂COONH₄(a mixture of average molecular weights 750; where n9 and n10 are as defined above).

As described above, examples of the anionic fluorosurfactant include a carboxylic acid surfactant and a sulfonic acid surfactant.

The polymerization initiator is not particularly limited as long as it can generate radicals in the above polymerization temperature range, and a known oil-soluble and/or water-soluble polymerization initiator can be used. The polymerization may be further initiated in a redox form in combination with a reducing agent or the like. The concentration of the polymerization initiator is appropriately determined depending on the kind of the monomer, the molecular weight of the target fluoropolymer, and the reaction rate.

As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, and examples thereof include the following peroxides: dialkyl peroxycarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate; peroxyesters such as tert-butyl peroxyisobutyrate and tert-butyl peroxypivalate; dialkyl peroxides such as di-tert-butyl peroxide; and di (omega-hydro-dodecafluoroheptanoyl) peroxide, di (omega-hydro-tetradecafluoroheptanoyl) peroxide, di (omega-hydro-hexadecafluorononoyl) peroxide, di (perfluorobutanoyl) peroxide, di (perfluoropentanoyl) peroxide, di (perfluorohexanoyl) peroxide, di (perfluoroheptanoyl) peroxide, di (perfluorooctanoyl) peroxide, di (perfluorononanoyl) peroxide, di (omega-chloro-hexafluorobutanoyl) peroxide, di (omega-chloro-decafluorohexanoyl) peroxide, di (omega-chloro-tetradecafluorooctanoyl) peroxide, omega-hydro-dodecafluoroheptanoyl-omega-hydroxyhexadecafluorononoyl-peroxide, omega-chloro-hexafluorobutanoyl-omega-chloro-decafluorohexanoyl-peroxide, di (omega-chloro-tetradecafluorooctanoyl) peroxide, omega-hydro-dodecafluoroheptanoyl-omega-hydroxyhexadecafluorononyl-peroxide, omega-chloro-decafluorohexanoyl-peroxide, Di [ perfluoro (or fluorochloro) acyl ] peroxides such as ω -hydroxydodecafluoroheptanoyl-perfluorobutanoyl-peroxide, di (dichloropentafluorobutanoyl) peroxide, di (trichlorooctafluorohexanoyl) peroxide, di (tetrachloroundecanooctanoyl) peroxide, di (pentachlorotridecanoyl) peroxide, and di (undecanoyl-triacontadoxodidodecanoyl) peroxide; and the like.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples thereof include ammonium salts such as persulfuric acid, perchloric acid and percarbonic acid, potassium salts, sodium salts, organic peroxides such as disuccinic acid peroxide and dipentanedioic acid peroxide, t-butyl peroxymaleate, t-butyl hydroperoxide, and the like. The reducing agent can also be contained, and the dosage of the reducing agent is 0.1-20 times of that of the peroxide.

For example, when the polymerization is carried out at a low temperature of 30 ℃ or lower, a redox initiator in which an oxidizing agent and a reducing agent are combined is preferably used as the polymerization initiator. Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, cerium ammonium nitrate, and the like. Examples of the reducing agent include bromate, diimine, and oxalic acid. Examples of the persulfate include ammonium persulfate and potassium persulfate. In order to increase the decomposition rate of the initiator, it is also preferable to add a copper salt or an iron salt to the combination of the redox initiators. Copper salt may be copper (II) sulfate, and iron salt may be iron (II) sulfate.

Examples of the redox initiator include potassium permanganate/oxalic acid, ammonium persulfate/bisulfite/iron (II) sulfate, ammonium persulfate/sulfite, ammonium persulfate/iron (II) sulfate, manganese triacetate/oxalic acid, cerium ammonium nitrate/oxalic acid, bromate/sulfite, bromate/bisulfite, and the like, with potassium permanganate/oxalic acid, and ammonium persulfate/sulfite/iron (II) sulfate being preferred. In the case of using a redox initiator, either an oxidizing agent or a reducing agent may be charged into a polymerization vessel in advance, and then the other may be continuously or intermittently added to initiate polymerization. For example, in the case of using potassium permanganate/oxalic acid, it is preferable to charge oxalic acid to the polymerization vessel and continuously add potassium permanganate thereto.

The amount of the polymerization initiator to be added is not particularly limited, and may be added at once, or sequentially, or continuously in the initial stage of the polymerization in an amount (for example, several ppm with respect to the concentration of water) or more to such an extent that the polymerization rate is not significantly lowered. The upper limit is a range in which the heat of polymerization reaction can be removed from the apparatus surface and the reaction temperature can be increased, and the more preferable upper limit is a range in which the heat of polymerization reaction can be removed from the apparatus surface.

The aqueous medium refers to a liquid containing water as a reaction medium for allowing polymerization to proceed. The aqueous medium is not particularly limited as long as it contains water, and may contain water and a non-fluorine-containing organic solvent such as an alcohol, an ether, or a ketone and/or a fluorine-containing organic solvent having a boiling point of 40 ℃ or lower.

In the above polymerization, a known chain transfer agent, radical scavenger or decomposer may be added to adjust the polymerization rate or molecular weight, depending on the purpose.

Examples of the chain transfer agent include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, and dimethyl succinate, and halogenated hydrocarbons such as isopentane, methane, ethane, propane, methanol, isopropanol, acetone, mercaptans, and carbon tetrachloride, and cyclohexane.

As the chain transfer agent, a bromine compound or an iodine compound can be used. Examples of the polymerization method using a bromine compound or an iodine compound include a method of polymerizing a fluoromonomer in an aqueous medium in the presence of a bromine compound or an iodine compound in a substantially oxygen-free state (iodine transfer polymerization method). Representative examples of the bromine compound or iodine compound to be used include compounds represented by the general formula:

R^aI_xBr_y

(wherein x and y are each an integer of 0 to 2 and satisfy 1. ltoreq. x + y. ltoreq.2, R^aIs a saturated or unsaturated fluorocarbon group or chlorofluorocarbon group having 1 to 16 carbon atoms or a hydrocarbon group having 1 to 3 carbon atoms, R^aMay contain an oxygen atom). By using a bromine compound or an iodine compound, iodine or bromine is introduced into the polymer to function as a crosslinking point.

Examples of the bromine compound and iodine compound include 1, 3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1, 3-diiodo-2-chloroperfluoropropane, 1, 4-diiodoperfluorobutane, 1, 5-diiodo-2, 4-dichloroperfluoropentane, 1, 6-diiodoperfluorohexane, 1, 8-diiodoperfluorooctane, 1, 12-diiodoperfluorododecane, 1, 16-diiodoperfluorohexadecane, diiodomethane, 1, 2-diiodoethane, 1, 3-diiodo-n-propane, CF ₂Br₂、BrCF₂CF₂Br、CF₃CFBrCF₂Br、CFClBr₂、BrCF₂CFClBr、CFBrClCFClBr、BrCF₂CF₂CF₂Br、BrCF₂CFBrOCF₃1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutaneAn alkane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluoro-1-butene, 2-bromo-4-iodoperfluoro-1-butene, a monoiodomonobromo substituent of benzene, a diiodomonobromo substituent, and a (2-iodoethyl) and (2-bromoethyl) substituent, and the like, and these compounds may be used alone or in combination with each other.

Among these, 1, 4-diiodoperfluorobutane, 1, 6-diiodoperfluorohexane and 2-iodoperfluoropropane are preferably used from the viewpoints of polymerization reactivity, crosslinking reactivity, availability and the like.

The amount of the chain transfer agent is usually 1 to 50,000ppm, preferably 1 to 20,000ppm, based on the total amount of the fluorine monomer to be supplied.

The chain transfer agent may be added to the reaction vessel at a time before the start of polymerization, may be added at a time after the start of polymerization, may be added in several portions during polymerization, or may be continuously added during polymerization.

The radical scavenger is a compound that does not have a capability of reinitiation after addition or chain transfer to a radical in the polymerization system. Specifically, a compound having the following functions is used: easily undergo a chain transfer reaction with a primary radical or a propagating radical, and then generate a stable radical which does not react with a monomer; alternatively, it is easy to generate a stable radical by addition reaction with a primary radical or a propagating radical.

The activity of a substance generally called a chain transfer agent is characterized by a chain transfer constant and a reinitiation efficiency, and a substance having a reinitiation efficiency of almost 0% among the chain transfer agents is called a radical scavenger.

The radical scavenger is, for example, a compound having a chain transfer constant to the fluoromonomer at the polymerization temperature higher than the polymerization rate constant and having a reinitiation efficiency of substantially 0%. "the reinitiation efficiency is substantially 0%" means that the radical scavenger is a stable radical by the generated radical.

Preferably, the chain transfer constant (Cs) to the fluoromonomer at the polymerization temperature (k) is greater than 0.1, and the chain transfer constant (Cs) of the above compound is more preferably 0.5 or more, still more preferably 1.0 or more, still more preferably 5.0 or more, and particularly preferably 10 or more.

The radical scavenger in the present invention is preferably selected from the group consisting of aromatic hydroxy compounds, aromatic amines, N-diethylhydroxylamine, quinone compounds, terpenes, thiocyanates and copper chloride (CuCl)₂) At least 1 of the group consisting of.

Examples of the aromatic hydroxy compound include unsubstituted phenol, polyhydric phenol, salicylic acid, m-or p-salicylic acid, gallic acid, naphthol, and the like.

Examples of the unsubstituted phenol include o-nitrophenol, m-nitrophenol, p-nitrophenol, o-aminophenol, m-aminophenol, p-aminophenol, and p-nitrosophenol. Examples of the polyhydric phenol include catechol, resorcinol, hydroquinone, pyrogallol, phloroglucinol, and m-naphthalenediol.

Examples of the aromatic amines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and benzidine.

Examples of the quinone compound include o-benzoquinone, m-benzoquinone, p-benzoquinone, 1, 4-naphthoquinone, and alizarin.

The thiocyanate may be ammonium thiocyanate (NH)₄SCN), potassium thiocyanate (KSCN), sodium thiocyanate (NaSCN), and the like.

Among these, aromatic hydroxy compounds are preferable, unsubstituted phenols or polyhydric phenols are more preferable, and hydroquinone is further preferable.

The amount of the radical scavenger added is preferably 3 to 500% (on a molar basis) based on the concentration of the polymerization initiator, from the viewpoint of reducing the standard specific gravity. The lower limit is more preferably 5% (on a molar basis), still more preferably 8% (on a molar basis), still more preferably 10% (on a molar basis), still more preferably 13% (on a molar basis) or 15% (on a molar basis), particularly preferably 20% (on a molar basis), particularly preferably 25% (on a molar basis), particularly preferably 30% (on a molar basis), and particularly preferably 35% (on a molar basis). The upper limit is more preferably 400% (on a molar basis), still more preferably 300% (on a molar basis), still more preferably 200% (on a molar basis), and particularly preferably 100% (on a molar basis).

The decomposition agent of the polymerization initiator may be any compound that can decompose the polymerization initiator used, and is preferably at least 1 selected from the group consisting of sulfite, bisulfite, bromate, diimine salt, oxalic acid, oxalate, copper salt, and iron salt, for example. Examples of the sulfite include sodium sulfite and ammonium sulfite. Copper salt may be copper (II) sulfate, and iron salt may be iron (II) sulfate.

The amount of the decomposition agent added to the polymerization initiator (redox initiator) is in the range of 3 to 300 mass% based on the amount of the oxidizing agent combined with the polymerization initiator. Preferably 3 to 150 mass%, and more preferably 15 to 100 mass%.

The amount of the above-mentioned decomposition agent for the polymerization initiator is preferably an amount corresponding to 3 to 500% (on a molar basis) of the concentration of the polymerization initiator, from the viewpoint of reducing the standard specific gravity. The lower limit is more preferably 5% (on a molar basis), still more preferably 8% (on a molar basis), still more preferably 10% (on a molar basis), yet more preferably 13% (on a molar basis), and yet more preferably 15% (on a molar basis). The upper limit is more preferably 400% (on a molar basis), still more preferably 300% (on a molar basis), still more preferably 200% (on a molar basis), and particularly preferably 100% (on a molar basis).

In the polymerization of the fluoromonomer, it is preferable to add the radical scavenger or the decomposition agent of the polymerization initiator when the concentration of the fluoropolymer formed in the aqueous medium (concentration based on the total of the aqueous medium and the fluoropolymer) is 5% by mass or more. More preferably 8% by mass or more, and still more preferably 10% by mass or more.

It is also preferable to add the fluoropolymer when the concentration of the fluoropolymer formed in the aqueous medium is 40% by mass or less. More preferably 35% by mass or less, and still more preferably 30% by mass or less.

In the polymerization of the fluoromonomer, a radical scavenger or a decomposer of a polymerization initiator may be continuously added. In the polymerization of the fluoromonomer, the radical scavenger or the decomposition agent of the polymerization initiator may be added not at once but intermittently or separately over time.

The production method of the present invention may comprise a step (I) of polymerizing the fluoromonomer in an aqueous medium in the presence of a hydrocarbon surfactant to produce an aqueous dispersion of fluoropolymer (a) particles, and a step (II) of polymerizing (seed-polymerizing) the fluoromonomer into the fluoropolymer (a) particles in the aqueous dispersion of fluoropolymer (a) particles.

Examples of the fluoropolymer include a TFE polymer in which TFE is the monomer having the largest mole fraction of monomers in the polymer (hereinafter referred to as the "largest monomer"), a VDF polymer in which VDF is the largest monomer, and a CTFE polymer in which CTFE is the largest monomer.

Further, as the fluoropolymer, (I) a non-melt-processible fluororesin, there may be mentioned a tetrafluoroethylene polymer [ TFE Polymer (PTFE) ], as (II) a melt-processible fluororesin, there may be mentioned an ethylene/TFE copolymer [ ETFE ], a TFE/HFP copolymer [ FEP ], a TFE/perfluoro (alkyl vinyl ether) copolymer [ PFA, MFA, etc. ], a TFE/perfluoroallyl ether copolymer, a TFE/VDF copolymer, an electrolyte polymer precursor, as (III) a fluororubber, there may be mentioned a TFE/propylene copolymer, a TFE/propylene/3 rd monomer copolymer (the 3 rd monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ethers, etc.), a copolymer composed of TFE and fluoroalkyl vinyl ethers; HFP/ethylene copolymers, HFP/ethylene/TFE copolymers; PVDF; thermoplastic elastomers such as VDF/HFP copolymer, HFP/ethylene copolymer, VDF/TFE/HFP copolymer; and a fluorine-containing segmented polymer described in Japanese patent publication No. 61-49327.

The TFE polymer is preferably a TFE homopolymer, and may be a copolymer composed of (1) TFE, (2) 1 or 2 or more fluorine-containing monomers other than TFE having 2 to 8 carbon atoms, particularly VDF, HFP, or CTFE, and (3) other monomers. Examples of the other monomer (3) include fluorine (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; fluoro-1, 3-dioxole; a perfluoroalkylethylene; omega-hydrogen perfluoroolefins, and the like.

The TFE polymer may be a copolymer of TFE and 1 or 2 or more types of non-fluorine-containing monomers. Examples of the non-fluorine-containing monomer include olefins such as ethylene and propylene; vinyl esters; vinyl ethers. The TFE polymer may be a copolymer of TFE, 1 or 2 or more fluorine-containing monomers having 2 to 8 carbon atoms, and 1 or 2 or more non-fluorine-containing monomers.

The VDF polymer may preferably be a VDF homopolymer [ PVDF ], or a copolymer composed of (1) VDF, (2) a fluoroolefin other than 1 or 2 or more VDFs having 2 to 8 carbon atoms, particularly TFE, HFP, or CTFE, and (3) perfluoro (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms.

The CTFE polymer may preferably be a CTFE homopolymer, or may be a copolymer composed of (1) CTFE, (2) a fluoroolefin other than 1 or 2 or more CTFE having 2 to 8 carbon atoms, particularly TFE or HFP, and (3) perfluoro (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms.

The CTFE polymer may be a copolymer of CTFE and 1 or 2 or more types of non-fluorine-containing monomers, and examples of the non-fluorine-containing monomers include olefins such as ethylene and propylene; vinyl esters; vinyl ethers, and the like.

The fluoropolymer may be glassy, plastic or elastomeric. These fluoropolymers are amorphous or partially crystalline and can be used in compression-firing processes, melt processes or non-melt processes.

In the above polymerization, for example, a tetrafluoroethylene polymer [ TFE Polymer (PTFE) ] as a non-melt-processable fluororesin (I), an ethylene/TFE copolymer [ ETFE ], a TFE/HFP copolymer [ FEP ], a TFE/perfluoro (alkyl vinyl ether) copolymer [ PFA, MFA, etc. ], a TFE/perfluoroallyl ether copolymer, a TFE/VDF copolymer, an electrolyte polymer precursor, a TFE/propylene copolymer as a (III) fluororubber, a TFE/propylene/3 rd monomer copolymer (the 3 rd monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ethers, etc.), a copolymer composed of TFE and fluoroalkyl vinyl ethers; HFP/ethylene copolymers, HFP/ethylene/TFE copolymers; PVDF; thermoplastic elastomers such as VDF/HFP copolymer, HFP/ethylene copolymer, VDF/TFE/HFP copolymer; and a fluorine-containing segmented polymer described in Japanese patent publication No. 61-49327.

The fluoropolymer is preferably a fluororesin, more preferably a fluororesin having a fluorine substitution rate of 50% or more, further preferably a fluororesin having a fluorine substitution rate of more than 50%, further more preferably a fluororesin having a fluorine substitution rate of 55% or more, further more preferably a fluororesin having a fluorine substitution rate of 60% or more, further more preferably a fluororesin having a fluorine substitution rate of 75% or more, particularly preferably a fluororesin having a fluorine substitution rate of 80% or more, and most preferably a fluororesin having a fluorine substitution rate of 90 to 100%, that is, a perfluororesin.

(formula (II))

The fluorine substitution rate (%)/((number of hydrogen atoms bonded to carbon atoms constituting the fluoropolymer) + (number of fluorine atoms and chlorine atoms bonded to carbon atoms constituting the fluoropolymer)) × 100

The perfluoro resin is preferably a fluororesin having a fluorine substitution rate of 95 to 100%, more preferably PTFE, FEP, PFA, particularly preferably PTFE, and most preferably high molecular weight PTFE.

The fluoropolymer may have a core-shell structure. Examples of the fluoropolymer having a core-shell structure include PTFE in which a core of PTFE having a high molecular weight and a shell of PTFE having a lower molecular weight or modified PTFE are contained in particles. Examples of such PTFE include PTFE described in japanese unexamined patent publication No. 2005-527652.

The core-shell structure may have the following structure.

And (3) nucleus: TFE homopolymer shell: TFE homopolymers

And (3) nucleus: modified PTFE shell: TFE homopolymers

And (3) nucleus: modified PTFE shell: modified PTFE

And (3) nucleus: TFE homopolymer shell: modified PTFE

And (3) nucleus: low molecular weight PTFE shell: high molecular weight PTFE

And (3) nucleus: high molecular weight PTFE shell: low molecular weight PTFE

In the fluoropolymer having a core-shell structure, the lower limit of the proportion of the core is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the proportion of the core is preferably 99.5% by mass, more preferably 99.0% by mass, still more preferably 98.0% by mass, still more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

In the fluoropolymer having a core-shell structure, the lower limit of the proportion of the shell is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the proportion of the shell is preferably 99.5% by mass, more preferably 99.0% by mass, still more preferably 98.0% by mass, still more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

In the fluoropolymer having a core-shell structure, the core or the shell may have a structure of 2 or more layers. For example, the fluoropolymer may have a 3-layer structure including a core center portion of modified PTFE, a core outer layer portion of TFE homopolymer, and a shell of modified PTFE.

Further, as the fluoropolymer having the core-shell structure, there can be mentioned a fluoropolymer in which 1 particle of the fluoropolymer has a plurality of cores.

The above-mentioned (I) non-melt-processable fluororesin, (II) melt-processable fluororesin, and (III) fluororubber are preferably produced in the following manner.

(I) Non-melt-processable fluororesin

In the production method of the present invention, polymerization of TFE is usually carried out at a polymerization temperature of 10 to 150 ℃ and a polymerization pressure of 0.05 to 5 MpaG. For example, the polymerization temperature is more preferably 30 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is more preferably 120 ℃ or lower, and still more preferably 100 ℃ or lower. The polymerization pressure is more preferably 0.3MPaG or more, further preferably 0.5MPaG or more, and still more preferably 5.0MPaG or less, further preferably 3.0MPaG or less. In particular, from the viewpoint of increasing the yield of the fluoropolymer, it is preferably 1.0MPaG or more, more preferably 1.2MPaG or more, still more preferably 1.5MPaG or more, and still more preferably 2.0MPaG or more.

In one embodiment, in the above polymerization, pure water is charged into a pressure-resistant reaction vessel equipped with a stirrer, TFE is charged after deoxygenation, the temperature is adjusted to a predetermined temperature, and a polymerization initiator is added to initiate the reaction. When the pressure decreases as the reaction proceeds, additional TFE is continuously or intermittently additionally supplied to maintain the initial pressure. When a predetermined amount of TFE was supplied, the supply was stopped, and TFE in the reaction vessel was purged to return the temperature to room temperature, thereby terminating the reaction. Additional TFE may be continuously or intermittently additionally supplied so as not to decrease the pressure.

In the production of the above-mentioned TFE Polymer (PTFE), various known modified monomers may be used in combination. In the present specification, the TFE polymer is a concept including not only a TFE homopolymer but also a non-melt-processable material (hereinafter, referred to as "modified PTFE") which is a copolymer of TFE and a modified monomer.

Examples of the modified monomer include: perhaloolefins such as HFP and CTFE; a fluorine (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; cyclic fluorinated monomers such as fluoro-1, 3-dioxole; perhaloalkylethylenes; omega-hydrogenated perhaloolefins, and the like. The modified monomer may be supplied in an initial stage by one-shot addition or continuously or intermittently by divided addition depending on the purpose and the supply of TFE.

When the TFE polymer is Polytetrafluoroethylene (PTFE), various conventionally known modified monomers other than TFE may be used in combination. In the present specification, the PTFE is a concept including not only a TFE homopolymer but also a non-melt-processable material (hereinafter referred to as "modified PTFE") which is a copolymer of TFE and a modified monomer.

The total amount of the modified monomer unit is preferably in the range of 0.00001 to 1.0 mass% relative to the total polymerized units of PTFE. The lower limit of the total amount is more preferably 0.0001% by mass, still more preferably 0.001% by mass, and yet more preferably 0.005% by mass. The upper limit is preferably 0.90 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.05 mass% in this order.

In the present specification, the modified monomer unit refers to a portion derived from a modified monomer as a part of the molecular structure of the TFE polymer.

Examples of the modifying monomer include perhaloolefins such as HFP, CTFE, and perfluorovinyl ether; a fluorine (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; cyclic fluorinated monomers such as fluoro-1, 3-dioxole; perhaloalkylethylenes such as (perfluoroalkyl) ethylenes; omega-hydrogenated perhaloolefins, and the like. The modified monomer may be supplied in an initial stage by one-shot addition or continuously or intermittently by divided addition depending on the purpose and the supply of TFE.

The modifying monomer is not particularly limited as long as it is copolymerizable with TFE, and examples thereof include fluorine monomers and fluorine-free monomers. The modifying monomer used may be 1 type or plural types.

The fluorine-free monomer is not particularly limited, and examples thereof include those represented by the general formula:

CH₂＝CR^Q1-LR^Q2

(in the formula, R^Q1Represents a hydrogen atom or an alkyl group. L represents a single bond, -CO-O-, -O-CO-, or-O-. Is represented by the formula^Q2The bonding position of (2). R^Q2Represents a hydrogen atom, an alkyl group or a nitrile group. ) The monomers indicated.

Examples of the fluorine-free monomer include methacrylic acid esters, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, vinyl acetate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, ethyl vinyl ether, cyclohexyl vinyl ether and the like. Among the fluorine-free monomers, butyl methacrylate, vinyl acetate and acrylic acid are preferable.

Examples of the fluoromonomer include perfluoroolefins such as hexafluoropropylene [ HFP ]; hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride [ VDF ]; perhaloolefins such as chlorotrifluoroethylene; a perfluorovinyl ether; (perfluoroalkyl) ethylene; perfluoroallyl ether, and the like.

The perfluorovinyl ether is not particularly limited, and examples thereof include the following general formula (3A):

CF₂＝CF-ORf (3A)

and (wherein Rf represents a perfluoroorganic group) a perfluorounsaturated compound. In the present specification, the "perfluoro organic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced with fluorine atoms. The perfluoro organic group may have an etheric oxygen.

Examples of the perfluorovinyl ether include perfluoro (alkyl vinyl ether) [ PAVE ] in which Rf in the general formula (3A) is a perfluoroalkyl group having 1 to 10 carbon atoms. The perfluoroalkyl group preferably has 1 to 5 carbon atoms.

Examples of the perfluoroalkyl group in PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

The perfluorovinyl ether may further include those having a C4-9 perfluoro (alkoxyalkyl) group as Rf in the general formula (3A), and having the following formula:

[ solution 8]

(wherein m represents 0 or an integer of 1 to 4.) and Rf is represented by the formula:

[ solution 9]

(wherein n represents an integer of 1 to 4.) and the like.

As the hydrogen-containing fluoroolefin, CH may be mentioned ₂＝CF₂、CFH＝CH₂、CFH＝CF₂、CF₂＝CFCF₃、CH₂＝CFCF₃、CH₂＝CHCF₃、CHF＝CHCF₃(E-form), CHF ═ CHCF₃(Z body), etc.

The (perfluoroalkyl) ethylene (PFAE) is not particularly limited, and examples thereof include (perfluorobutyl) ethylene (PFBE), and (perfluorohexyl) ethylene.

Examples of the perfluoroallyl ether include

A compound of the general formula: CF (compact flash)₂＝CF-CF₂-ORf

(wherein Rf represents a perfluoroorganic group.) or a fluorinated monomer.

Rf in the above formula is the same as Rf in the formula (A). Rf is preferably a C1-10 perfluoroalkyl group or a C1-10 perfluoroalkoxyalkyl group. As the perfluoroallyl ether, it is preferably selected from the group consisting of CF₂＝CF-CF₂-O-CF₃、CF₂＝CF-CF₂-O-C₂F₅、CF₂＝CF-CF₂-O-C₃F₇And CF₂＝CF-CF₂-O-C₄F₉At least 1 of the group consisting of CF, more preferably CF₂＝CF-CF₂-O-C₂F₅、CF₂＝CF-CF₂-O-C₃F₇And CF₂＝CF-CF₂-O-C₄F₉At least 1 of the group consisting of, more preferably CF₂＝CF-CF₂-O-CF₂CF₂CF₃。

When PTFE, which is a fluoropolymer, is produced using TFE as a fluoromonomer, an aqueous PTFE dispersion can be produced that has high stability to the extent that subsequent processability, moldability, and the like are not impaired, and that can give a molded article having high heat resistance, by including (polyfluoroalkyl) ethylene and/or a comonomer (3) having a monomer reactivity ratio rTFE of 0.1 to 8 in copolymerization with TFE in the polymerization system at the start of polymerization of TFE so as to be 0.001 to 0.01 mass% relative to the amount of PTFE produced at the end.

Here, the monomer reactivity ratio in copolymerization with TFE means a value obtained by dividing a rate constant at the time when the propagating radical reacts with TFE by a rate constant at the time when the propagating radical reacts with TFE, when the propagating radical is smaller than the repeating unit based on TFE. The lower the value, the higher the reactivity of the comonomer with TFE. The reactivity ratio can be calculated as follows: the composition of the polymer formed immediately after the initiation of copolymerization of a comonomer with TFE was determined at various feed compositions, and the reactivity ratio was calculated from the above composition by Fineman-Ross equation.

The copolymerization was carried out in a stainless steel autoclave having an internal volume of 6.0L using 3600g of deionized and degassed water, 1000ppm of ammonium perfluorooctanoate relative to the water, and 100g of paraffin wax under a pressure of 0.78MPaG at a temperature of 70 ℃. Into the reactor were charged 0.05g, 0.1g, 0.2g, 0.5g and 1.0g of a comonomer, respectively, and 0.072g of ammonium persulfate (20 ppm relative to water) was charged, and TFE was continuously supplied so as to maintain a polymerization pressure of 0.78 MpaG. When the amount of TFE fed reached 1000g, the stirring was stopped and the pressure was released until the reactor reached atmospheric pressure. After cooling, the paraffin wax was separated, thereby obtaining an aqueous dispersion containing the resulting polymer. The resulting aqueous dispersion was stirred to coagulate the polymer, and dried at 150 ℃. The composition of the resulting polymer was calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of the monomer.

The modified monomer is preferably a comonomer (3) having a monomer reactivity ratio of 0.1 to 8. By the presence of the comonomer (3), PTFE particles having a small particle diameter can be obtained, and an aqueous dispersion having high dispersion stability can be obtained.

The comonomer (3) having a monomer reactivity ratio of 0.1 to 8 is preferably at least 1 selected from the group consisting of comonomers represented by the formulae (3a) to (3 d). CH (CH)₂＝CH-Rf¹ (3a)

(in the formula, wherein,Rf¹is a perfluoroalkyl group having 1 to 10 carbon atoms. )

CF₂＝CF-O-Rf² (3b)

(wherein Rf²Is a perfluoroalkyl group having 1 to 2 carbon atoms. )

CF₂＝CF-O-(CF₂)_nCF＝CF₂ (3c)

(wherein n is 1 or 2.)

[ solution 10]

(in the formula, X³And X⁴F, Cl or methoxy, Y is of formula Y1 or Y2. )

[ solution 11]

-CF＝CF- (Y1)

(in the formula Y2, Z and Z' are F or a fluorinated alkyl group having 1 to 3 carbon atoms.)

The content of the comonomer (3) unit is preferably in the range of 0.0001 to 1.0 mass% with respect to the total polymerized units of PTFE. The lower limit is more preferably 0.0001% by mass, still more preferably 0.0005% by mass, yet more preferably 0.001% by mass, and particularly preferably 0.005% by mass. The upper limit is preferably 0.90 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.08 mass%, 0.05 mass%, 0.01 mass%.

The above-mentioned modifying monomer is preferably at least 1 selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, perfluoro (alkyl vinyl ether), (perfluoroalkyl) ethylene, and a modifying monomer having a functional group capable of reacting in radical polymerization and a hydrophilic group, for the reason that an aqueous dispersion having a small average primary particle diameter, a small aspect ratio of primary particles, and excellent stability can be obtained. By using the modified monomer, an aqueous dispersion of PTFE having a small average primary particle diameter, a small aspect ratio of primary particles, and excellent dispersion stability can be obtained.

From the viewpoint of reactivity with TFE, the above-mentioned modifying monomer preferably contains at least 1 selected from the group consisting of hexafluoropropylene, perfluoro (alkyl vinyl ether), and (perfluoroalkyl) ethylene.

More preferably at least 1 selected from the group consisting of hexafluoropropylene, perfluoro (methyl vinyl ether), perfluoro (propyl vinyl ether), (perfluorobutyl) ethylene, (perfluorohexyl) ethylene and (perfluorooctyl) ethylene.

The total amount of the hexafluoropropylene unit, perfluoro (alkyl vinyl ether) unit, and (perfluoroalkyl) ethylene unit is preferably 0.00001 to 1.0 mass% based on the total polymerized units of PTFE. The lower limit of the total amount is more preferably 0.0001% by mass, still more preferably 0.0005% by mass, yet more preferably 0.001% by mass, particularly preferably 0.005% by mass, and particularly preferably 0.009% by mass. The upper limit is preferably 0.9 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.08 mass%, 0.05 mass%, 0.01 mass%.

The above-mentioned modifying monomer also preferably contains a modifying monomer having a functional group capable of reacting in radical polymerization and a hydrophilic group (hereinafter referred to as "modifying monomer (a)").

The presence of the modified monomer (a) can provide PTFE particles having a small primary particle diameter, and can provide an aqueous dispersion having high dispersion stability. In addition, the aspect ratio of the primary particles can be reduced.

The amount of the modifying monomer (A) used is preferably an amount exceeding 0.1ppm, more preferably an amount exceeding 0.5ppm, still more preferably an amount exceeding 1.0ppm, even more preferably 5ppm or more, and particularly preferably 10ppm or more based on the aqueous medium. When the amount of the modified monomer (A) is too small, the particle diameter of the resulting PTFE may not decrease.

The amount of the modifying monomer (A) may be in the above range, and for example, the upper limit may be 5000 ppm. In the above production method, the modifying monomer (a) may be added to the system during the reaction in order to improve the stability of the aqueous dispersion during or after the reaction.

Since the water solubility of the modifying monomer (a) is high, even if the unreacted modifying monomer (a) remains in the aqueous dispersion, it can be easily removed by the concentration step or the condensation/washing step.

The modified monomer (a) is incorporated into the resulting polymer during the polymerization, but the concentration of the modified monomer (a) in the polymerization system is low and the amount of the modified monomer (a) incorporated into the polymer is small, and therefore, there is no problem that the heat resistance of PTFE is lowered or coloring after firing occurs.

Examples of the hydrophilic group in the modified monomer (A) include-NH₂、-PO₃M、-P(O)(OM)₂、-OPO₃M、-OP(O)(OM)₂、-SO₃M、-OSO₃M and-COOM (in the formula, M is H, metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r⁷Are H or organic radicals, which may be identical or different. Any 2 of them may be bonded to each other to form a ring. ). As the hydrophilic group. Among them, preferred is-SO₃M or-COOM.

As R⁷The organic group in (1) is preferably an alkyl group. As R⁷Preferably H or C_1-10More preferably H or C_1-4Further preferably H or C_1-4Alkyl group of (1).

Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li.

Examples of the "functional group capable of reacting in radical polymerization" in the modified monomer (a) include groups having an ethylenically unsaturated bond such as a vinyl group and an allyl group. The group having an ethylenically unsaturated bond may be represented by the formula:

CX₁X₃＝CX₂R-

(in the formula, X₁、X₂And X₃Each independently of the other is F, Cl, H, CF₃、CF₂H、CFH₂Or CH₃(ii) a R is a linking group. ) And (4) showing. Examples of the linking group of R include the following R^aA linking group of (a).

Preferably, the group-CH ═ CH₂、-CF＝CH₂、-CH＝CF₂、-CF＝CF₂、-CH₂-CH＝CH₂、-CF₂-CF＝CH₂、-CF₂-CF＝CF₂、-(C＝O)-CH＝CH₂、-(C＝O)-CF＝CH₂、-(C＝O)-CH＝CF₂、-(C＝O)-CF＝CF₂、-(C＝O)-C(CH₃)＝CH₂、-(C＝O)-C(CF₃)＝CH₂、-(C＝O)-C(CH₃)＝CF₂、-(C＝O)-C(CF₃)＝CF₂、-O-CH₂-CH＝CH₂、-O-CF₂-CF＝CH₂、-O-CH₂-CH＝CF₂、-O-CF₂-CF＝CF₂And the like having an unsaturated bond.

Since the modified monomer (a) has a functional group capable of reacting in radical polymerization, it is presumed that the modified monomer (a) reacts with a fluorine-containing monomer at the initial stage of polymerization reaction to form particles having a hydrophilic group derived from the modified monomer (a) and high stability when used in the polymerization. Therefore, it is considered that the number of particles increases when the polymerization is carried out in the presence of the modified monomer (A).

In the above polymerization, the modified monomer (a) may be present in 1 kind, or may be present in 2 or more kinds.

In the above polymerization, as the modifying monomer (a), a compound having an unsaturated bond can be used.

The modifying monomer (a) is preferably at least 1 selected from the group consisting of compounds represented by the general formula (4A).

CX¹X³＝CX²R^a-(CZ¹Z²)_k-Y³ (4A)

(in the formula, X¹、X²And X³Each independently of the others being F, Cl, H or CF₃；Y³Is a hydrophilic group; r^aIs a linking group; z¹And Z²Each independently H, F or CF₃K is 0 or 1)

Examples of the hydrophilic group include-NH₂、-PO₃M、-P(O)(OM)₂、-OPO₃M、-OP(O)(OM)₂、-SO₃M、-OSO₃M and-COOM (in the formula, M is H, metal atom, NR) ⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r⁷Are H or organic radicals, which may be identical or different. Any 2 of them may be bonded to each other to form a ring. ). As the above hydrophilic group, among them, -SO is preferred₃M or-COOM. As R⁷Preferably H or C_1-10More preferably H or C_1-4Further preferably H or C_1-4Alkyl group of (1).

Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li.

By using the modified monomer (a), an aqueous dispersion having a smaller average primary particle diameter and more excellent stability can be obtained. In addition, the aspect ratio of the primary particles can be made smaller.

R is as defined above^aIs a linking group. In the present specification, "linking group" means a divalent linking group. The linking group may be a single bond, preferably contains at least 1 carbon atom, and the number of carbon atoms may be 2 or more, may be 4 or more, may be 8 or more, may be 10 or more, and may be 20 or more. The upper limit is not limited, and may be, for example, 100 or less, or 50 or less.

The linking group may have a chain or branched chain structure, a cyclic or acyclic structure, a saturated or unsaturated structure, a substituted or unsubstituted structure, and may desirably include 1 or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen, and may desirably include 1 or more functional groups selected from the group consisting of esters, amides, sulfonamides, carbonyls, carbonates, carbamates, ureas, and carbamates (carbamates). The linking group does not contain carbon atoms and may be a catenary heteroatom such as oxygen, sulfur, or nitrogen.

R is as defined above^aFor example, a catenary heteroatom such as oxygen, sulfur, nitrogen, or a 2-valent organic group is preferable.

R^aIn the case of a 2-valent organic group, the hydrogen atom bonded to the carbon atom may be substituted with a halogen other than fluorine, for example, chlorine, and may or may not contain a double bond. In addition, R^aThe polymer may be either a linear or branched one, or a cyclic or acyclic one. In addition, R^aFunctional groups (e.g., esters, ethers, ketones, amines, halides, etc.) may be included.

In addition, R^aMay be a fluorine-free 2-valent organic group, or may be a partially fluorinated or perfluorinated 2-valent organic group.

As R^aExamples of the hydrocarbon group include a hydrocarbon group having no fluorine atom bonded to a carbon atom, a hydrocarbon group having a part of hydrogen atoms bonded to a carbon atom substituted with a fluorine atom, a hydrocarbon group having all hydrogen atoms bonded to a carbon atom substituted with a fluorine atom, and a hydrocarbon group containing- (C ═ O) -, - (C ═ O) -O-or- (C ═ O) -, and these hydrocarbon groups may contain an oxygen atom, a double bond, or a functional group.

R^aThe organic solvent is preferably a hydrocarbon group having 1 to 100 carbon atoms, which may or may not contain- (C ═ O) -, - (C ═ O) -O-, or an ether bond, and which may or may not contain- (C ═ O) -, and hydrogen atoms bonded to carbon atoms of the hydrocarbon group may be partially or completely substituted with fluorine.

As R^aPreferably selected from- (CH)₂)_a-、-(CF₂)_a-、-O-(CF₂)_a-、-(CF₂)_a-O-(CF₂)_b-、-O(CF₂)_a-O-(CF₂)_b-、-(CF₂)_a-[O-(CF₂)_b]_c-、-O(CF₂)_a-[O-(CF₂)_b]_c-、-[(CF₂)_a-O]_b-[(CF₂)_c-O]_d-、-O[(CF₂)_a-O]_b-[(CF₂)_c-O]_d-、-O-[CF₂CF(CF₃)O]_a-(CF₂)_b-、-(C＝O)-、-(C＝O)-O-、-(C＝O)-(CH₂)_a-、-(C＝O)-(CF₂)_a-、-(C＝O)-O-(CH₂)_a-、-(C＝O)-O-(CF₂)_a-、-(C＝O)-[(CH₂)_a-O]_b-、-(C＝O)-[(CF₂)_a-O]_b-、-(C＝O)-O[(CH₂)_a-O]_b-、-(C＝O)-O[(CF₂)_a-O]_b-、-(C＝O)-O[(CH₂)_a-O]_b-(CH₂)_c-、-(C＝O)-O[(CF₂)_a-O]_b-(CF₂)_c-、-(C＝O)-(CH₂)_a-O-(CH₂)_b-、-(C＝O)-(CF₂)_a-O-(CF₂)_b-、-(C＝O)-O-(CH₂)_a-O-(CH₂)_b-、-(C＝O)-O-(CF₂)_a-O-(CF₂)_b-、-(C＝O)-O-C₆H₄-and combinations thereof.

Wherein a, b, c and d are independently at least 1 or more. a. b, c and d may be independently 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. a. The upper limit of b, c and d is, for example, 100.

As R^aSpecific preferred example of (A) includes-CF₂-O-、-CF₂-O-CF₂-、-CF₂-O-CH₂-、-CF₂-O-CH₂CF₂-、-CF₂-O-CF₂CF₂-、-CF₂-O-CF₂CH₂-、-CF₂-O-CF₂CF₂CH₂-、-CF₂-O-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-、-CF₂-O-CF(CF₃)CF₂-O-、-CF₂-O-CF(CF₃)CH₂-、-(C＝O)-、-(C＝O)-O-、-(C＝O)-(CH₂)-、-(C＝O)-(CF₂)-、-(C＝O)-O-(CH₂)-、-(C＝O)-O-(CF₂)-、-(C＝O)-[(CH₂)₂-O]_n-、-(C＝O)-[(CF₂)₂-O]_n-、-(C＝O)-O[(CH₂)₂-O]_n-、-(C＝O)-O[(CF₂)₂-O]_n-、-(C＝O)-O[(CH₂)₂-O]_n-(CH₂)-、-(C＝O)-O[(CF₂)₂-O]_n-(CF₂)-、-(C＝O)-(CH₂)₂-O-(CH₂)-、-(C＝O)-(CF₂)₂-O-(CF₂)-、-(C＝O)-O-(CH₂)₂-O-(CH₂)-、-(C＝O)-O-(CF₂)₂-O-(CF₂)-、-(C＝O)-O-C₆H₄-and the like. Wherein R is as defined above^aParticularly preferred is-CF₂-O-、-CF₂-O-CF₂-、-CF₂-O-CF₂CF₂-、-CF₂-O-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-、-CF₂-O-CF(CF₃)CF₂-O-、-(C＝O)-、-(C＝O)-O-、-(C＝O)-(CH₂)-、-(C＝O)-O-(CH₂)-、-(C＝O)-O[(CH₂)₂-O]_n-、-(C＝O)-O[(CH₂)₂-O]_n-(CH₂)-、-(C＝O)-(CH₂)₂-O-(CH₂) -or- (C ═ O) -O-C₆H₄-。

In the formula, n is an integer of 1 to 10.

as-R in the above general formula (4A)^a-(CZ¹Z²)_kpreferably-CF₂-O-CF₂-、-CF₂-O-CF(CF₃)-、-CF₂-O-C(CF₃)₂-、-CF₂-O-CF₂-CF₂-、-CF₂-O-CF₂-CF(CF₃)-、-CF₂-O-CF₂-C(CF₃)₂-、-CF₂-O-CF₂CF₂-CF₂-、-CF₂-O-CF₂CF₂-CF(CF₃)-、-CF₂-O-CF₂CF₂-C(CF₃)₂-、-CF₂-O-CF(CF₃)-CF₂-、-CF₂-O-CF(CF₃)-CF(CF₃)-、-CF₂-O-CF(CF₃)-C(CF₃)₂-、-CF₂-O-CF(CF₃)-CF₂-、-CF₂-O-CF(CF₃)-CF(CF₃)-、-CF₂-O-CF(CF₃)-C(CF₃)₂-、-CF₂-O-CF(CF₃)CF₂-CF₂-、-CF₂-O-CF(CF₃)CF₂-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-C(CF₃)₂-、-CF₂-O-CF(CF₃)CF₂-O-CF₂-、-CF₂-O-CF(CF₃)CF₂-O-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-O-C(CF₃)₂-、-(C＝O)-、-(C＝O)-O-、-(C＝O)-(CH₂)-、-(C＝O)-(CF₂)-、-(C＝O)-O-(CH₂)-、-(C＝O)-O-(CF₂)-、-(C＝O)-[(CH₂)₂-O]_n-(CH₂)-、-(C＝O)-[(CF₂)₂-O]_n-(CF₂)-、-(C＝O)-[(CH₂)₂-O]_n-(CH₂)-(CH₂)-、-(C＝O)-[(CF₂)₂-O]_n-(CF₂)-(CF₂)-、-(C＝O)-O[(CH₂)₂-O]_n-(CF₂)-、-(C＝O)-O[(CH₂)₂-O]_n-(CH₂)-(CH₂)-、-(C＝O)-O[(CF₂)₂-O]_n-(CF₂)-、-(C＝O)-O[(CF₂)₂-O]_n-(CF₂)-(CF₂)-、-(C＝O)-(CH₂)₂-O-(CH₂)-(CH₂)-、-(C＝O)-(CF₂)₂-O-(CF₂)-(CF₂)-、-(C＝O)-O-(CH₂)₂-O-(CH₂)-(CH₂)-、-(C＝O)-O-(CF₂)₂-O-(CF₂)-(CF₂)-、-(C＝O)-O-(CH₂)₂-O-(CH₂)-C(CF₃)₂-、-(C＝O)-O-(CF₂)₂-O-(CF₂)-C(CF₃)₂-or- (C ═ O) -O-C₆H₄-C(CF₃)₂-, more preferably-CF₂-O-CF(CF₃)-、-CF₂-O-CF₂-CF(CF₃)-、-CF₂-O-CF₂CF₂-CF(CF₃)-、-CF₂-O-CF(CF₃)-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-CF(CF₃)-、-CF₂-O-CF(CF₃)CF₂-O-CF(CF₃)-、-(C＝O)-、-(C＝O)-O-(CH₂)-、-(C＝O)-O-(CH₂)-(CH₂)-、-(C＝O)-O[(CH₂)₂-O]_n-(CH₂)-(CH₂)-、-(C＝O)-O-(CH₂)₂-O-(CH₂)-C(CF₃)₂-or- (C ═ O) -O-C₆H₄-C(CF₃)₂-。

In the formula, n is an integer of 1 to 10.

Specific examples of the compound represented by the general formula (4A) include

[ solution 12]

(in the formula, X^jAnd Y³As described above. n is an integer of 1 to 10. ) And the like.

As R^aPreferably, the following general formula (r 1):

-(C＝O)_h-(O)_i-CF₂-O-(CX⁶ ₂)_e-{O-CF(CF₃)}_f-(O)_g- (r1)

(in the formula, X⁶Each independently H, F or CF₃E is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1), and the following general formula (r2) is further preferable:

-(C＝O)_h-(O)_i-CF₂-O-(CX⁷ ₂)_e-(O)_g- (r2) (formula, X)⁷Each independently H, F or CF₃E is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1. ) The 2-valent radical as shown.

Further, R in the above general formula (4A)^a-(CZ¹Z²)_kAlso preferred is the following formula (t 1):

-(C＝O)_h-(O)_i-CF₂-O-(CX⁶ ₂)_e-{O-CF(CF₃)}_f-(O)_g-CZ¹Z²-(t1)

(in the formula, X⁶Each independently H, F or CF₃E is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, Z¹And Z²Each independently is F or CF₃) The 2-valent group represented by the formula (t1), Z is more preferably Z¹And Z²One is F and the other is CF₃。

In the above general formula (4A), the group represented by the formula-R^a-(CZ¹Z²)_kAlso preferred is the following formula (t 2):

-(C＝O)_h-(O)_i-CF₂-O-(CX⁷ ₂)_e-(O)_g-CZ¹Z²- (t2)

(in the formula, X⁷Each independently H, F or CF₃E is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, Z¹And Z²Each independently H, F or CF₃) The 2-valent group represented by the formula (t2), Z is more preferably Z¹And Z²One is F and the other is CF₃。

The compound represented by the general formula (4A) is also preferably selected from the hydrophilic group (Y)³) And has no C-H bond other than the C-F bond. That is, in the general formula (4A), X is preferableⁱ、X^jAnd X^kAll are F, R^aIs a perfluoroalkylene group having 1 or more carbon atoms, and the perfluoroalkylene group may be either a linear or branched chain, either a cyclic or acyclic, or both Comprising at least 1 catenary heteroatom. The number of carbon atoms of the perfluoroalkylene group may be 2 to 20, or 4 to 18.

The compound represented by the general formula (4A) may be partially fluorinated. That is, the compound represented by the general formula (4A) is also preferably selected from the hydrophilic group (Y)³) And has at least 1 hydrogen atom bonded to a carbon atom and has at least 1 fluorine atom bonded to a carbon atom.

The compound represented by the general formula (4A) is preferably a compound represented by the following formula (4A).

CF₂＝CF-O-Rf⁰-Y³ (4a)

(in the formula, Y³Being a hydrophilic group, Rf⁰A perfluorinated divalent linking group which is perfluorinated, may have a chain or branched structure, a cyclic or acyclic structure, saturated or unsaturated, substituted or unsubstituted, and optionally additionally contains 1 or more heteroatoms selected from the group consisting of sulfur, oxygen and nitrogen. )

The compound represented by the general formula (4A) is preferably a compound represented by the following formula (4 b).

CH₂＝CH-O-Rf⁰-Y³ (4b)

(in the formula, Y³Being a hydrophilic group, Rf⁰Is a per-fluorinated divalent linking group as defined in formula (4 a). )

In the general formula (4A), Y³is-OSO₃M is one of the preferred modes. Y is³is-OSO₃In the case of M, CF is exemplified as the compound represented by the general formula (4A)₂＝CF(OCF₂CF₂CH₂OSO₃M)、CH₂＝CH((CF₂)₄CH₂OSO₃M)、CF₂＝CF(O(CF₂)₄CH₂OSO₃M)、CF₂＝CF(OCF₂CF(CF₃)CH₂OSO₃M)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂CH₂OSO₃M)、CH₂＝CH((CF₂)₄CH₂OSO₃M)、CF₂＝CF(OCF₂CF₂SO₂N(CH₃)CH₂CH₂OSO₃M)、CH₂＝CH(CF₂CF₂CH₂OSO₃M)、CF₂＝CF(OCF₂CF₂CF₂CF₂SO₂N(CH₃)CH₂CH₂OSO₃M)、CH₂＝CH(CF₂CF₂CH₂OSO₃M), and the like. In the above formula, M is the same as described above.

In the general formula (4A), Y ³is-SO₃M is also one of the preferred modes. Y is³is-SO₃In the case of M, CF is exemplified as the compound represented by the general formula (4A)₂＝CF(OCF₂CF₂SO₃M)、CF₂＝CF(O(CF₂)₄SO₃M)、CF₂＝CF(OCF₂CF(CF₃)SO₃M)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂SO₃M)、CH₂＝CH(CF₂CF₂SO₃M)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂CF₂CF₂SO₃M)、CH₂＝CH((CF₂)₄SO₃M)、CH₂＝CH(CF₂CF₂SO₃M)、CH₂＝CH((CF₂)₃SO₃M), and the like. In the above formula, M is the same as described above.

In the general formula (4A), Y³It is also one of the preferred modes to be-COOM. Y is³In the case of-COOM, CF is exemplified as the compound represented by the general formula (4A)₂＝CF(OCF₂CF₂COOM)、CF₂＝CF(OCF₂CF₂CF₂COOM)、CF₂＝CF(O(CF₂)₅COOM)、CF₂＝CF(OCF₂CF(CF₃)COOM)、CF₂＝CF(OCF₂CF(CF₃)O(CF₂)_nCOOM) (n is more than 1), CH₂＝CH(CF₂CF₂COOM)、CH₂＝CH((CF₂)₄COOM)、CH₂＝CH(CF₂CF₂COOM)、CH₂＝CH((CF₂)₃COOM)、CF₂＝CF(OCF₂CF₂SO₂NR’CH₂COOM)、CF₂＝CF(O(CF₂)₄SO₂NR’CH₂COOM)、CF₂＝CF(OCF₂CF(CF₃)SO₂NR’CH₂COOM)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂SO₂NR’CH₂COOM)、CH₂＝CH(CF₂CF₂SO₂NR’CH₂COOM)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂CF₂CF₂SO₂NR’CH₂COOM)、CH₂＝CH((CF₂)₄SO₂NR’CH₂COOM)、CH₂＝CH(CF₂CF₂SO₂NR’CH₂COOM)、CH₂＝CH((CF₂)₃SO₂NR’CH₂COOM), and the like. In the above formula, R' is H or C_1-4Alkyl, M are the same as described above.

In the general formula (4A), Y³is-OPO₃M or-OP (O) (OM)₂Is also one of the preferred modes. Y is³is-OPO₃M or-OP (O) (OM)₂In the case (4), CF is an example of the compound represented by the general formula (4A)₂＝CF(OCF₂CF₂CH₂OP(O)(OM)₂)、CF₂＝CF(O(CF₂)₄CH₂OP(O)(OM)₂)、CF₂＝CF(OCF₂CF(CF₃)CH₂OP(O)(OM)₂)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂CH₂OP(O)(OM)₂)、CF₂＝CF(OCF₂CF₂SO₂N(CH₃)CH₂CH₂OP(O)(OM)₂)、CF₂＝CF(OCF₂CF₂CF₂CF₂SO₂N(CH₃)CH₂CH₂OP(O)(OM)₂)、CH₂＝CH(CF₂CF₂CH₂OP(O)(OM)₂、CH₂＝CH((CF₂)₄CH₂OP(O)(OM)₂)、CH₂＝CH(CF₂CF₂CH₂OP(O)(OM)₂)、CH₂＝CH((CF₂)₃CH₂OP(O)(OM)₂) And the like. In the above formula, M is the same as described above.

In the general formula (4A), Y³is-PO₃M or-P (O) (OM)₂Is also one of the preferred modes. Y is³is-PO₃M or-P (O) (OM)₂In the case (4), CF is an example of the compound represented by the general formula (4A)₂＝CF(OCF₂CF₂P(O)(OM)₂)、CF₂＝CF(O(CF₂)₄P(O)(OM)₂)、CF₂＝CF(OCF₂CF(CF₃)P(O)(OM)₂)、CF₂＝CF(OCF₂CF(CF₃)OCF₂CF₂P(O)(OM)₂)、CH₂＝CH(CF₂CF₂P(O)(OM)₂)、CH₂＝CH((CF₂)₄P(O)(OM)₂)、CH₂＝CH(CF₂CF₂P(O)(OM)₂)、CH₂＝CH((CF₂)₃P(O)(OM)₂) And the like, wherein M is the same as described above.

The compound represented by the above general formula (4A) is preferably selected from the compounds represented by the following general formula (5A):

CX₂＝CY(-CZ₂-O-Rf-Y³) (5A)

(wherein X is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, and Z is-H, -F, alkyl or fluoroalkyl, and Rf is a fluoroalkylene group having 1 to 40 carbon atoms or a fluoroalkylene group having an ether bond and having 2 to 100 carbon atoms ³As described above. ) The monomer represented by the following general formula (6A):

CX₂＝CY(-O-Rf-Y³) (6A)

(wherein X is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, and Rf is C1-40A fluorinated alkylene group or a fluorinated alkylene group having 2 to 100 carbon atoms and an ether bond. Y is³As described above. ) A monomer represented by the following general formula (7A):

CX₂＝CY(-Rf-Y³) (7A)

(wherein X is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, Rf is C1-40 fluoroalkylene or C2-100 fluoroalkylene having ether bond; Y is the same or different³As described above. ) At least 1 of the group consisting of the monomers represented.

In the general formula (5A), X is-H or-F. X may be both-H, both may be-F, or at least 1 may be-H. For example, one may be-F and the other may be-H, or both may be-H.

In the general formula (5A), Y is-H, -F, alkyl or fluoroalkyl.

The alkyl group is an alkyl group containing no fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

The fluoroalkyl group may contain at least 1 fluorine atom, and may contain 1 or more carbon atoms. The number of carbon atoms of the fluoroalkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

As Y, preferred is-H, -F or-CF₃And more preferably-F.

In the above general formula (5A), Z is-H, -F, alkyl or fluoroalkyl, which may be the same or different.

The alkyl group is an alkyl group containing no fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

The fluoroalkyl group may contain at least 1 fluorine atom, and may contain 1 or more carbon atoms. The number of carbon atoms of the fluoroalkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

As the above Z, preferred is-H, -F or-CF₃And more preferably-F.

In the general formula (5A), it is preferable that at least 1 of X, Y and Z is a fluorine atom. For example, X may be-H, Y and Z may be-F.

In the general formula (5A), Rf is a C1-40 fluoroalkylene group or a C2-100 fluoroalkylene group having an ether bond.

The number of carbon atoms of the fluorinated alkylene group is preferably 2 or more. Further, it is preferably 30 or less, more preferably 20 or less, and further preferably 10 or less. Examples of the fluoroalkylene group include-CF₂-、-CH₂CF₂-、-CF₂CF₂-、-CF₂CH₂-、-CF₂CF₂CH₂-、-CF(CF₃)-、-CF(CF₃)CF₂-、-CF(CF₃)CH₂-and the like. The above-mentioned fluoroalkylene group is preferably a perfluoroalkylene group.

The number of carbon atoms of the fluorinated alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms of the fluorinated alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, and still more preferably 12 or less.

As the fluorine-containing alkylene group having an ether bond, for example, the following formula is also preferable:

[ solution 13]

(in the formula, Z¹Is F or CF₃；Z²And Z³Are H or F respectively; z⁴Is H, F or CF₃(ii) a p1+ q1+ r1 is an integer of 0-10; s1 is 0 or 1; t1 is an integer of 0 to 5).

Specific examples of the fluorinated alkylene group having an ether bond include-CF (CF)₃)CF₂-O-CF(CF₃)-、-(CF(CF₃)CF₂-O)_n-CF(CF₃) - (wherein n is an integer of 1 to 10), -CF (CF)₃)CF₂-O-CF(CF₃)CH₂-、-(CF(CF₃)CF₂-O)_n-CF(CF₃)CH₂- (wherein n is an integer of 1 to 10), -CH₂CF₂CF₂O-CH₂CF₂CH₂-、-CF₂CF₂CF₂O-CF₂CF₂-、-CF₂CF₂CF₂O-CF₂CF₂CH₂-、-CF₂CF₂O-CF₂-、-CF₂CF₂O-CF₂CH₂-and the like. The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

In the above general formula (5A), Y³preferably-COOM, -SO₃M or-OSO₃M (M is H, metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r⁷Are H or organic radicals, which may be identical or different. Any 2 of them may be bonded to each other to form a ring. ).

As R⁷The organic group in (1) is preferably an alkyl group. As R⁷Preferably H or C_1-10More preferably H or C _1-4Further preferably H or C_1-4Alkyl group of (1).

Examples of the metal atom include alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable.

As the above M, preferred is-H, a metal atom or-NR⁷ ₄More preferably-H, alkali metal (group 1), alkaline earth metal (group 2) or-NR⁷ ₄Further, it is preferably-H, -Na, -K, -Li or-NH₄Further more preferably-Na, -K or-NH₄Particularly preferred is-Na or-NH₄Most preferably-NH₄。

As the above Y³preferably-COOM or-SO₃M, more preferably-COOM.

The monomer represented by the general formula (5A) is preferably a monomer (5A) represented by the following general formula (5A).

CH₂＝CF(-CF₂-O-Rf-Y³)(5a)

(wherein Rf and Y³As described above. )

Specific examples of the monomer represented by the general formula (5a) include

[ solution 14]

(in the formula, Z¹Is F or CF₃；Z²And Z³Are H or F respectively; z⁴Is H, F or CF₃(ii) a p1+ q1+ r1 is an integer of 0-10; s1 is 0 or 1; t1 is an integer of 0 to 5, Y³As described above. Wherein Z is³And Z⁴P1+ q1+ r1+ s1 is not 0) in the case of all H. More specifically, preferred examples thereof include

[ solution 15]

Etc. in which

[ solution 16]

Is preferred.

As the monomer represented by the above general formula (5a), Y in the formula (5a)³Is preferably-COOM, particularly preferably selected from the group consisting of CH ₂＝CFCF₂OCF(CF₃) COOM and CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃) COOM (wherein M is as defined above). ) At least 1 of the group consisting of, more preferably CH₂＝CFCF₂OCF(CF₃)COOM。

The monomer represented by the general formula (5A) is preferably a monomer (5b) represented by the following general formula (5 b).

CX² ₂＝CFCF₂-O-(CF(CF₃)CF₂O)_n5-CF(CF₃)-Y³ (5b)

(in the formula, each X²The same indicates F or H. n5 represents 0 or an integer of 1 to 10, Y³As defined above. )

In the formula (5b), n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, from the viewpoint of stability of the aqueous dispersion obtained. Y is above³The preferred one is-COOM in view of obtaining appropriate water solubility and stability of the aqueous dispersion, and H or NH in view of preventing the M from remaining as an impurity and improving the heat resistance of the resulting molded article₄。

Examples of the perfluorovinyl alkyl compound represented by the formula (5b) include CH₂＝CFCF₂OCF(CF₃)COOM、CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃) COOM (wherein M is as defined above). ).

Further, examples of the monomer represented by the general formula (5A) include a monomer represented by the following general formula (5 c).

CF₂＝CFCF₂-O-Rf-Y³ (5c)

(wherein Rf and Y³Same as above)

More specifically, there may be mentioned

[ solution 17]

And the like.

In the general formula (6A), X is-H or-F. X may be both F or at least 1X may be H. For example, one may be-F and the other may be-H, or both may be-H.

In the general formula (6A), Y is-H, -F, alkyl or fluoroalkyl.

The alkyl group is an alkyl group containing no fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

The fluoroalkyl group may contain at least 1 fluorine atom, and may contain 1 or more carbon atoms. The number of carbon atoms of the fluoroalkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less.

As Y, preferred is-H, -F or-CF₃And more preferably-F.

In the general formula (6A), it is preferable that at least 1 of X and Y is a fluorine atom. For example, X may be-H, Y and Z may be-F.

In the general formula (6A), Rf is a C1-40 fluoroalkylene group or a C2-100 fluoroalkylene group having an ether bond.

The number of carbon atoms of the fluorinated alkylene group is preferably 2 or more. The number of carbon atoms of the fluorinated alkylene group is preferably 30 or less, more preferably 20 or less, and still more preferably 10 or less. Examples of the fluoroalkylene group include-CF₂-、-CH₂CF₂-、-CF₂CF₂-、-CF₂CH₂-、-CF₂CF₂CH₂-、-CF(CF₃)-、-CF(CF₃)CF₂-、-CF(CF₃)CH₂-and the like. The above-mentioned fluoroalkylene group is preferably a perfluoroalkylene group.

In the above general formula (6A), Y³preferably-COOM, -SO ₃M or-OSO₃M (M is H, metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r⁷Are H or organic radicals, which may be identical or different. Any 2 of them may be bonded to each other to form a ring. ).

As R⁷The organic group of (2) is preferably an alkyl group. As R⁷Preferably H or C_1-10More preferably H or C_1-4Further preferably H or C_1-4Alkyl group of (1).

Examples of the metal atom include alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable.

As the above M, preferred are-H and a metalAtom or-NR⁷ ₄More preferably-H, alkali metal (group 1), alkaline earth metal (group 2) or-NR⁷ ₄Further, it is preferably-H, -Na, -K, -Li or-NH₄Further more preferably-Na, -K or-NH₄Particularly preferred is-Na or-NH₄Most preferably-NH₄。

As the above Y³preferably-COOM or-SO₃M, more preferably-COOM.

The monomer represented by the above general formula (6A) is preferably at least 1 selected from the group consisting of monomers represented by the following general formulae (6A), (6b), (6c), (6d) and (6 e).

CF₂＝CF-O-(CF₂)_n1-Y³ (6a)

(wherein n1 represents an integer of 1 to 10, and Y represents³As defined above. )

CF₂＝CF-O-(CF₂C(CF₃)F)_n2-Y³ (6b)

(wherein n2 represents an integer of 1 to 5, and Y represents ³As defined above. )

CF₂＝CF-O-(CFX¹)_n3-Y³ (6c)

(in the formula, X¹Represents F or CF₃N3 represents an integer of 1 to 10, Y³As defined above. )

CF₂＝CF-O-(CF₂CFX¹O)_n4-(CF₂)_n6-Y³ (6d)

(wherein n4 represents an integer of 1 to 10, n6 represents an integer of 1 to 3, and Y represents³And X¹As defined above. )

CF₂＝CF-O-(CF₂CF₂CFX¹O)_n5-CF₂CF₂CF₂-Y³ (6e)

(wherein n5 represents an integer of 0 to 10, and Y represents³And X¹As defined above. )

In the formula (6a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. Y is above³From is availablepreferably-COOM in terms of appropriate water solubility and stability of the aqueous dispersion, and preferably H or NH in terms of difficulty in remaining as impurities and improvement in heat resistance of the resulting molded article₄。

Examples of the monomer represented by the formula (6a) include CF₂＝CF-O-CF₂COOM、CF₂＝CF(OCF₂CF₂COOM)、CF₂＝CF(OCF₂CF₂CF₂COOM) (wherein M is as defined above. ).

In the above formula (6b), n2 is preferably an integer of 3 or less, and Y is preferably an integer of 3 or less from the viewpoint of stability of the aqueous dispersion obtained³The preferred one is-COOM in view of obtaining appropriate water solubility and stability of the aqueous dispersion, and the preferred one is H or NH in view of preventing M from remaining as an impurity and improving heat resistance of the resulting molded article₄。

In the formula (6c), n3 is preferably an integer of 5 or less, and Y is preferably an integer of 5 or less from the viewpoint of water solubility ³The preferable range is-COOM in that appropriate water solubility and stability of the aqueous dispersion can be obtained, and the preferable range of M is H or NH in that dispersion stability is good₄。

In the above formula (6d), the X is a group represented by the formula¹preferably-CF₃In view of water solubility, n4 is preferably an integer of 5 or less, and Y is an integer of 5 or less in view of obtaining appropriate water solubility and stability of the aqueous dispersion³preferably-COOM, and the above M is preferably H or NH₄。

Examples of the monomer represented by the formula (6d) include CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOM、CF₂＝CFOCF₂CF(CF₃)OCF₂COOM、CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂CF₂OOM (wherein M represents H, NH₄Or an alkali metal. ).

In the general formula (6e), n5 is n5 in view of water solubilityPreferably an integer of 5 or less, and Y is an integer of 5 or less, from the viewpoint of obtaining an appropriate water solubility and excellent sedimentation stability of the composition³preferably-COOM, and the above M is preferably H or NH₄。

Examples of the monomer represented by the general formula (6e) include CF₂＝CFOCF₂CF₂CF₂COOM (wherein M represents H, NH)₄Or an alkali metal. ).

In the general formula (7A), Rf is preferably a C1-40 fluoroalkylene group. In the general formula (7A), it is preferable that at least 1 of X and Y is a fluorine atom.

The monomer represented by the above general formula (7A) is preferably selected from the group consisting of the following general formula (7A):

CF₂＝CF-(CF₂)_n1-Y³ (7a)

(wherein n1 represents an integer of 1 to 10, and Y represents³As defined above. ) A monomer represented by the following general formula (7 b):

CF₂＝CF-(CF₂C(CF₃)F)_n2-Y³ (7b)

(wherein n2 represents an integer of 1 to 5, and Y represents³As defined above. ) At least 1 of the group consisting of the monomers represented.

Y is above³Is preferably-SO₃M or-COOM, M preferably being H, a metal atom, NR⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. R is as defined above⁷Represents H or an organic group.

In the formula (7a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. Y is above³The preferred one is-COOM in view of obtaining appropriate water solubility and stability of the aqueous dispersion, and the preferred one is H or NH in view of preventing M from remaining as an impurity and improving heat resistance of the resulting molded article₄。

The perfluorovinyl alkyl compound represented by the formula (7a) includes, for example, CF₂＝CFCF₂COOM (wherein M is as defined above)The same is true. ).

In the above formula (7b), n2 is preferably an integer of 3 or less, and Y is preferably an integer of 3 or less from the viewpoint of stability of the aqueous dispersion obtained³The preferred one is-COOM in view of obtaining appropriate water solubility and stability of the aqueous dispersion, and the preferred one is H or NH in view of preventing M from remaining as an impurity and improving heat resistance of the resulting molded article ₄。

The modifying monomer preferably contains the modifying monomer (a), preferably contains at least 1 selected from the group consisting of compounds represented by general formula (5a), general formula (5b), general formula (6a), general formula (6b), general formula (6c), and general formula (6d), and more preferably contains a compound represented by general formula (5a) or general formula (5 b).

The content of the modifying monomer (a) is preferably in the range of 0.00001 to 1.0 mass%. The lower limit is more preferably 0.0001% by mass, still more preferably 0.001% by mass, and yet more preferably 0.005% by mass. The upper limit is preferably 0.90 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.08 mass%, 0.05 mass%, 0.01 mass%.

In the production of the TFE polymer, the hydrocarbon surfactant may be used in the above range. The concentration of the hydrocarbon surfactant is not particularly limited as long as it is within the above range, and is usually added at the Critical Micelle Concentration (CMC) or less at the start of polymerization. When the amount of the surfactant is large, needle-like particles having a large aspect ratio are formed, and the aqueous dispersion is in the form of a gel, which deteriorates stability. The lower limit of the amount of the hydrocarbon surfactant to be used is preferably 0.0001% by mass, more preferably 0.001% by mass, even more preferably 0.01% by mass, and particularly preferably 0.1% by mass, based on the aqueous medium. The upper limit of the amount of the hydrocarbon surfactant to be used is preferably 10% by mass, more preferably 5% by mass, even more preferably 3% by mass, and particularly preferably 2% by mass, based on the aqueous medium.

The hydrocarbon surfactant may be added to the reaction vessel at a time before the start of polymerization, may be added at a time after the start of polymerization, may be added in several portions during polymerization, or may be continuously added during polymerization.

In the production of the TFE polymer, a persulfate (e.g., ammonium persulfate), disuccinic acid peroxide, dipentanedioic acid peroxide, or other organic peroxide can be used alone or as a mixture thereof as a polymerization initiator. Further, it may be used as a redox system in combination with a reducing agent such as sodium sulfite. Further, a radical scavenger such as hydroquinone or catechol, or a decomposition agent for peroxide such as ammonium sulfite may be added during the polymerization to adjust the radical concentration in the system.

As the redox-type polymerization initiator, a redox initiator in which an oxidizing agent and a reducing agent are combined is preferably used. Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, cerium ammonium nitrate, and the like. Examples of the reducing agent include sulfite, bisulfite, bromate, diimine, oxalic acid, and the like. Examples of the persulfate include ammonium persulfate and potassium persulfate. Examples of the sulfite include sodium sulfite and ammonium sulfite. In order to increase the decomposition rate of the initiator, it is also preferable to add a copper salt or an iron salt to the combination of the redox initiators. Copper salt may be copper (II) sulfate, and iron salt may be iron (II) sulfate.

Examples of the redox initiator include potassium permanganate/oxalic acid, ammonium persulfate/bisulfite/ferric sulfate, manganese triacetate/oxalic acid, cerium ammonium nitrate/oxalic acid, bromate/bisulfite, and the like, with potassium permanganate/oxalic acid being preferred. In the case of using a redox initiator, either an oxidizing agent or a reducing agent may be charged into a polymerization vessel in advance, and then the other may be continuously or intermittently added to initiate polymerization. For example, in the case of using potassium permanganate/oxalic acid, it is preferable to charge oxalic acid to the polymerization vessel and continuously add potassium permanganate thereto.

In the production of the TFE polymer, a known chain transfer agent can be used as the chain transfer agent, and examples thereof include saturated hydrocarbons such as methane, ethane, propane, and butane, halogenated hydrocarbons such as methyl chloride, methylene chloride, and difluoroethane, alcohols such as methanol, ethanol, and isopropyl alcohol, and hydrogen, and preferably a chain transfer agent in a gaseous state at normal temperature and pressure.

The amount of the chain transfer agent is usually 1 to 10000ppm, preferably 1 to 5000ppm, based on the total amount of TFE supplied.

In the production of the TFE polymer, a saturated hydrocarbon having 12 or more carbon atoms, which is substantially inert in the reaction and is liquid under the reaction conditions, may be used as a dispersion stabilizer for the reaction system in an amount of 2 to 10 parts by mass based on 100 parts by mass of the aqueous medium. As a buffer for adjusting the pH during the reaction, ammonium carbonate, ammonium phosphate, or the like may be added.

At the time of terminating the polymerization of the TFE polymer, an aqueous dispersion containing a TFE polymer having a solid content of 1.0 to 70 mass% and an average primary particle diameter of 50 to 500nm can be obtained. The aqueous dispersion liquid contains the hydrocarbon surfactant and a fluoropolymer. Further, by using the above-mentioned hydrocarbon surfactant, an aqueous dispersion of particles composed of a TFE polymer having a fine particle diameter of 0.5 μm or less can be obtained.

The lower limit of the solid content concentration is preferably 5% by mass, and more preferably 8% by mass. The upper limit is not particularly limited, and may be 40 mass% or 35 mass%.

The lower limit of the average primary particle diameter is preferably 100nm, and more preferably 150 nm. The upper limit is preferably 400nm, more preferably 350 nm.

Fine powder can be produced by condensing the aqueous dispersion of the TFE polymer obtained in the production process of the present invention. The aqueous dispersion of the above-mentioned TFE polymer is coagulated, washed and dried to obtain a fine powder which can be used for various purposes. When the aqueous dispersion of the TFE polymer is coagulated, an aqueous dispersion obtained by polymerization such as a polymer emulsion is usually diluted with water to a polymer concentration of 5 to 20 mass%, and after adjusting the pH to neutral or alkaline according to circumstances, the aqueous dispersion is stirred in a vessel with a stirrer more vigorously than during the reaction. In the above condensation, the water-soluble organic compound such as methanol or acetone, an inorganic salt such as potassium nitrate or ammonium carbonate, an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, or the like may be added as a flocculant while stirring. The condensation may be continuously performed by using a line mixer or the like.

From the viewpoint of productivity, the concentration of the non-coagulated TFE polymer in the wastewater produced by the flocculation is preferably low, more preferably less than 0.4 mass%, and particularly preferably less than 0.3 mass%.

Before or during the above-mentioned coagulation, a pigment for coloring or various fillers for improving mechanical properties are added to obtain a fine powder of a TFE polymer containing a pigment or a filler, which is uniformly mixed with the pigment or the filler.

The wet powder obtained by condensing the aqueous dispersion of TFE polymer is usually dried by vacuum, high frequency, hot air, or other means while keeping the wet powder in a state where it hardly flows, preferably in a state where it is left to stand. Friction between powders, particularly at high temperatures, often adversely affects TFE polymers in the form of fine powders. This is because such particles composed of TFE polymer have a property of being easily fibrillated even by a small shearing force to lose the state of the originally stable particle structure.

The drying is carried out at a drying temperature of 10 to 300 ℃ (10 to 250 ℃), preferably 100 to 300 ℃ (100 to 200 ℃).

The obtained TFE polymer fine powder is preferably used for molding, and suitable applications include pipes for hydraulic systems and fuel systems of aircrafts, automobiles, and the like, and flexible hoses for reagents, steam, and the like, and electric wire coating applications, and the like.

In addition, it is also preferable that an aqueous dispersion of TFE polymer is stabilized by adding a nonionic surfactant, and further concentrated, and an organic or inorganic filler is added according to the purpose to prepare a composition, which is used for various applications. The composition can be coated on a substrate made of metal or ceramic to form a coating film surface having non-tackiness, a low coefficient of friction, gloss, smoothness, abrasion resistance, weather resistance and heat resistance, and is suitable for coating of a roll, a cooking utensil or the like, impregnation of a glass cloth, or the like.

Organosols of TFE polymers can also be prepared from aqueous dispersions of TFE polymers. The organosol may contain the TFE polymer and an organic solvent, and examples of the organic solvent include ether solvents, ketone solvents, alcohol solvents, amide solvents, ester solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and halogenated hydrocarbon solvents, and N-methyl-2-pyrrolidone, dimethylacetamide, and the like can be preferably used. The preparation of the organosol can be carried out, for example, by the method described in international publication No. 2012/002038.

An aqueous dispersion of TFE polymer or TFE polymer fine powder obtained from the aqueous dispersion is also preferably used as a processing aid. When used as a processing aid, the aqueous dispersion or the fine powder is mixed with a host polymer or the like, whereby the melt strength of the host polymer during melt processing can be improved, and the mechanical strength, electrical characteristics, flame retardancy, dripping resistance during combustion, and sliding properties of the obtained polymer can be improved.

The aqueous dispersion of the above-mentioned TFE polymer or the above-mentioned fine powder of TFE polymer is also preferably used as a binder for batteries and dust-proofing purposes.

The aqueous dispersion of the TFE polymer or the fine powder of the TFE polymer is preferably compounded with a resin other than the TFE polymer and then used as a processing aid. The aqueous dispersion or the fine powder is suitable as a raw material for PTFE described in, for example, Japanese patent application laid-open Nos. 11-49912, 5804654, 11-29679 and 2003-2980. The processing aid using the aqueous dispersion or the fine powder is also comparable to the processing aids described in the above publications.

The aqueous dispersion of TFE polymer is preferably mixed with an aqueous dispersion of a melt-processable fluororesin and coagulated to form a coagulated powder. The above-described cocoagulated powder is suitable as a processing aid.

Examples of the melt-processable fluororesin include FEP, PFA, TFE/perfluoroallyl ether copolymer, ETFE, ethylene/TFE/HFP copolymer [ EFEP ], and the like, and FEP is preferable.

The non-fluorine-containing resin to which the above-mentioned co-coagulated powder is added may be in the form of powder, granule or emulsion. From the viewpoint of sufficiently mixing the respective resins, it is preferable to perform the addition while applying a shearing force by a known method such as extrusion kneading or roll kneading.

The aqueous dispersion preferably further contains the melt-processable fluororesin. Examples of the melt-processable fluororesin include FEP, PFA, TFE/perfluoroallyl ether copolymer, ETFE, and EFEP. An aqueous dispersion of the TFE polymer containing the melt-processable fluororesin may be used as a coating material. The melt-processable fluororesin can sufficiently fuse the particles of the TFE polymer, and thus can improve the film-forming property and give a gloss to the obtained film.

The use of the aqueous dispersion is not particularly limited, and examples of the use of the aqueous dispersion as it is include: coating by applying the coating to a substrate, drying the coating, and then firing the coating as needed; impregnation by impregnating a porous support such as a nonwoven fabric or a resin molded article with the resin, drying the impregnated support, and then preferably firing the dried support; examples of the application include a cast film formed by coating a substrate such as glass on the substrate, drying the substrate, immersing the substrate in water if necessary, and peeling the substrate to obtain a thin film, and examples of the application include an aqueous dispersion type paint, a tent film, a conveyor belt, a printed circuit board (CCL), an electrode binder, and an electrode water repellent.

The aqueous dispersion of TFE polymer is also preferably used as a dust-suppressing treatment agent. The dust-suppressing treatment agent can be used in the following method: a method in which a TFE polymer is fibrillated by mixing the TFE polymer with a dusting substance and applying a compression-shearing action to the mixture at a temperature of 20 to 200 ℃ to suppress dust of the dusting substance; for example, Japanese patent No. 2827152 and Japanese patent No. 2538783.

The aqueous dispersion of TFE polymer can be suitably used in, for example, a dust-inhibiting treatment agent composition described in international publication No. 2007/004250, and can also be suitably used in a dust-inhibiting treatment method described in international publication No. 2007/000812.

The dust-inhibiting agent is suitably used for dust-inhibiting treatment in the fields of building materials, soil stabilizers, solidification materials, fertilizers, incineration ash, and filling treatment of harmful substances, explosionproof, cosmetics, and pet litter including cat litter.

The aqueous Dispersion of TFE polymer is preferably used as a raw material for obtaining TFE polymer fibers by a Dispersion Spinning method (Dispersion Spinning method). The dispersion spinning method is a method comprising: the aqueous dispersion of the TFE polymer is mixed with an aqueous dispersion of a matrix polymer, the mixture is extruded to form an intermediate fiber structure, and the intermediate fiber structure is fired to decompose the matrix polymer and sinter the TFE polymer particles, thereby obtaining a TFE polymer fiber.

High molecular weight PTFE can also be made using the surfactants described above. That is, in the production method of the present invention using the above surfactant, surprisingly, PTFE having a molecular weight equivalent to that in the production method using the conventional fluorosurfactant can be produced without using the conventional fluorosurfactant.

The high molecular weight PTFE powder obtained by polymerization has stretchability and non-melt processability, and is also useful as a raw material for a stretched body (porous body).

When the stretched product is a film (stretched PTFE film or porous PTFE membrane), stretching can be performed by a known PTFE stretching method. By stretching, the high molecular weight PTFE is easily fibrillated to form a PTFE porous body (film) composed of nodules and fibers.

The paste extrudate in the form of a sheet or a rod is preferably roll-stretched in the extrusion direction, whereby a uniaxially stretched film can be obtained.

It is also possible to obtain a biaxially stretched film by further stretching in the width direction with a tenter or the like.

It is also preferable to perform a semi-firing treatment before stretching.

The stretched PTFE body is a porous body having a high porosity,

can be suitably used as a filter medium for various precision filtration filters such as air filters and reagent filters, a support material for polymer electrolyte membranes, and the like.

Further, the resin composition is also useful as a material for products used in the fields of fibers, medical treatment, electrochemistry, sealing materials, air filtration, ventilation/internal pressure control, liquid filtration, general consumables, and the like.

The following illustrates a specific use.

Field of electrochemistry

Dielectric prepreg, EMI shielding material, heat transfer material, and the like. More specifically, there are a printed circuit board, an electromagnetic shielding material, an insulating heat transfer material, an insulating material, and the like.

Field of sealing materials

Gaskets, pump diaphragms, pump pipes, aircraft seals, and the like.

The field of air filtration

ULPA filters (for semiconductor manufacturing), HEPA filters (for hospital and semiconductor manufacturing), cylindrical cartridge filters (for industrial use), bag filters (for industrial use), heat-resistant bag filters (for exhaust gas treatment), heat-resistant pleated filters (for exhaust gas treatment), SINBRAN filters (for industrial use), catalytic filters (for exhaust gas treatment), filters with adsorbents (for HDD assembly), breather filters (for HDD assembly and the like), filters for vacuum cleaners (for vacuum cleaners), general-purpose multilayer felt materials, cartridge filters for GT (for GT compatible interchange), cooling filters (for electronic equipment housings), and the like.

Ventilation/internal pressure regulation field

A material for freeze drying such as a freeze drying container, a ventilation material for automobiles suitable for an electronic circuit or a lamp, a container suitable for container use such as a container cover, a protective ventilation use suitable for electronic equipment including a small terminal such as a tablet terminal or a mobile phone terminal, a medical ventilation use, and the like.

Field of liquid filtration

A filter for semiconductor liquid filtration (for semiconductor production), a hydrophilic PTFE filter (for semiconductor production), a filter suitable for chemicals (for reagent treatment), a filter for a pure water production line (for pure water production), a backwashing type liquid filtration filter (for industrial wastewater treatment), and the like.

Field of general consumable

Clothing, cable guide tubes (suitable for movable wires for motorcycles), clothing for motorcycles, cast padding (medical protectors), dust collector filters, horns (musical instruments), cables (signal cables for guitars, etc.), strings (for string instruments), and the like.

Field of fiber

PTFE fibers (fibrous materials), sewing threads (fabrics), knitting threads (fabrics), ropes, and the like.

Medical field

In vivo implants (stretchings), artificial blood vessels, catheters, general surgery (tissue reinforcement), head and neck products (dura mater substitutes), oral health (tissue regeneration medicine), plastic surgery (taping), and the like.

The use of the surfactant enables production of low-molecular-weight PTFE.

The low molecular weight PTFE can be produced by polymerization, or the high molecular weight PTFE obtained by polymerization can be produced by reducing the molecular weight thereof by a known method (thermal decomposition, radiation decomposition, or the like).

Low molecular weight PTFE (also referred to as PTFE fine powder) having a molecular weight of 60 ten thousand or less is excellent in chemical stability, extremely low in surface energy, and less prone to fibrillation, and is therefore suitable for the production of plastics, inks, cosmetics, paints, greases, office automation equipment parts, toners, and the like as an additive for the purpose of improving sliding properties, texture of the surface of a coating film, and the like (see, for example, japanese patent application laid-open No. 10-147617).

Further, low molecular weight PTFE can be obtained by further dispersing a polymerization initiator and the above surfactant in an aqueous medium in the presence of a chain transfer agent to polymerize TFE, or by polymerizing TFE with a monomer copolymerizable with TFE.

When the low molecular weight PTFE obtained by the polymerization is used as a powder, the aqueous dispersion is coagulated to prepare powder particles.

In the present invention, high molecular weight PTFE means PTFE having non-melt processability and fibrillating properties. On the other hand, low molecular weight PTFE refers to PTFE having melt processability and no fibrillation.

The above non-melt processability means that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point according to astm D1238 and D2116.

The presence or absence of fibrillation can be judged by "paste extrusion", which is a typical method for molding "high molecular weight PTFE powder" as a powder made from a polymer of TFE. In general, paste extrusion is possible because high molecular weight PTFE has fibrillating properties. When the green molded product obtained by paste extrusion has no substantial strength or elongation, for example, when the elongation is 0% and the molded product is broken during stretching, it is considered that the molded product has no fibrillation property.

The Standard Specific Gravity (SSG) of the high molecular weight PTFE is preferably 2.130 to 2.280. The standard specific gravity was measured by the water displacement method according to ASTM D792 using a sample molded according to ASTM D4895-89. In the present invention, "high molecular weight" means that the standard specific gravity is within the above range.

The low molecular weight PTFE has a complex viscosity of 1X 10 at 380 deg.C²～7×10⁵Pa · s. In the present invention, "low molecular weight" means that the complex viscosity is in the above range.

The complex viscosity of the high molecular weight PTFE is extremely high as compared with the low molecular weight PTFE, and it is difficult to measure the complex viscosity accurately. On the other hand, the complex viscosity of the low molecular weight PTFE can be measured, but it is difficult to obtain a molded article useful for measuring a standard specific gravity from the low molecular weight PTFE, and it is difficult to measure an accurate standard specific gravity. Therefore, in the present invention, the standard specific gravity is used as an index of the molecular weight of the high molecular weight PTFE, and the complex viscosity is used as an index of the molecular weight of the low molecular weight PTFE. In addition, a measurement method capable of directly determining the molecular weight of either the high molecular weight PTFE or the low molecular weight PTFE is not known.

The peak temperature of the high molecular weight PTFE is preferably 333 to 347 ℃, more preferably 335 to 345 ℃. The peak temperature of the low molecular weight PTFE is preferably 322 to 333 ℃, more preferably 324 to 332 ℃. The peak temperature is a temperature corresponding to the maximum value in the heat of fusion curve when the temperature of PTFE, which does not have a history of being heated to 300 ℃ or higher, is raised at a rate of 10 ℃/min using a differential scanning calorimeter [ DSC ]. The peak temperature can be determined as a temperature corresponding to a maximum value appearing in a Differential Thermal (DTA) curve obtained by heating PTFE, which does not have a history of being heated to a temperature of 300 ℃ or higher, using TG/DTA (differential thermogravimetric simultaneous measurement apparatus) under a condition of 10 ℃/min.

The high molecular weight PTFE preferably has at least 1 endothermic peak in the range of 333 to 347 ℃ in a heat of fusion curve when the temperature is raised at a rate of 10 ℃/min using a differential scanning calorimeter [ DSC ] for PTFE which does not have a history of being heated to a temperature of 300 ℃ or higher, and the heat of fusion at 290 to 350 ℃ calculated from the heat of fusion curve is 62mJ/mg or more.

An unfired tape (raw tape) can also be obtained from the PTFE fine powder obtained by using the surfactant.

The surfactant, the decomposed product or by-product of the surfactant by-product by the surfactant, and the residual monomer can be reused by recovering the surfactant, the decomposed product or by-product of the surfactant by-product by the surfactant, and the residual monomer from the waste water produced by the condensation or washing and/or the exhaust gas produced by the drying step and purifying the recovered surfactant. The method for recovering and purifying is not particularly limited, and the recovery and purification can be carried out by a known method. For example, the method can be performed by the method described in Japanese patent publication No. 2011-520020.

(II) melt-processable fluororesin

(1) In the production method of the present invention, polymerization of FEP is preferably carried out at a polymerization temperature of 10 to 150 ℃ and a polymerization pressure of 0.3 to 6.0 MpaG.

The preferred monomer composition (mass%) of FEP is TFE: HFP (60-98): (2-40), more preferably (60-95): (5-40), more preferably (85-92): (8-15). Further, as the FEP, perfluoro (alkyl vinyl ether) may be used as the component 3, and the modification may be carried out in a range of 0.1 to 2 mass% based on the total monomers.

In the polymerization of the FEP, the surfactant may be used in the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 10% by mass based on 100% by mass of the aqueous medium.

In the polymerization of FEP, cyclohexane, methanol, ethanol, propanol, ethane, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, methyl chloride, etc. are preferably used as the chain transfer agent, and ammonium carbonate, disodium hydrogen phosphate, etc. are preferably used as the pH buffer.

The aqueous dispersion of FEP obtained by the production method of the present invention is subjected to post-treatment such as concentration, and then dried to be powdered, and then melt-extruded to be made into pellets. The aqueous medium in the aqueous dispersion of FEP may contain additives such as nonionic surfactants, and may or may not contain a water-soluble organic solvent such as a water-soluble alcohol, as necessary.

The melt extrusion may be carried out under any extrusion conditions that can be generally used for producing pellets, and the extrusion conditions may be appropriately set.

In the production method of the present invention, the FEP obtained may have-CF at a position of at least one of the polymer main chain and the polymer side chain ₃、-CF₂H, etc., but preferably-COOH, -CH₂OH、-COF、-CF＝CF-、-CONH₂、-COOCH₃And the like, are low in content or are absent.

The unstable terminal group is unstable in chemical properties, and therefore, not only does the heat resistance of the resin decrease, but also it causes an increase in the attenuation of the obtained electric wire.

In the production process of the present invention, it is preferable to use an unstable terminal group and-CF₂The combined number of H end groups is 1X 10⁶The polymer at the time of termination of polymerization was produced so that the number of carbon atoms was 50 or less. More preferably 1X 10⁶The number of carbon atoms is less than 20, and more preferably 5 or less. The above-mentioned unstable terminal groups and-CF may also be absent₂H end groups and all being-CF₃A terminal group.

Unstable terminal group and-CF₂The H end groups can be converted to-CF by fluorination₃End groups to stabilize it. The fluorination treatment method is not particularly limited, and a method of exposing the polymer to a fluorine radical source that generates fluorine radicals under fluorination treatment conditions may be mentioned. Examples of the fluorine radical source include fluorine gas and CoF₃、AgF₂、UF₆、OF₂、N₂F₂、CF₃OF and halogen fluoride (e.g. IF)₅、ClF₃) And the like. Among these, a method of directly contacting the FEP obtained by the production method of the present invention with a fluorinated gas is preferable, and from the viewpoint of reaction control, the contacting is preferably performed using a diluted fluorine gas having a fluorine gas concentration of 10 to 50 mass%. The diluted fluorine gas can be obtained by diluting the fluorine gas with an inert gas such as nitrogen gas or argon gas. The fluorine gas treatment may be carried out at a temperature of 100 to 250 ℃. The treatment temperature is not limited to the above range, and may be set as appropriate according to the situation. The fluorine gas treatment is preferably carried out by supplying diluted fluorine gas into the reactor continuously or intermittently. The fluorination treatment may be performed on dried powder after polymerization or on melt-extruded pellets.

The FEP produced by the production method of the present invention has good moldability, is less likely to cause molding defects, and has good heat resistance, chemical resistance, solvent resistance, insulation properties, electrical properties, and the like.

The method for producing the FEP powder is a method for obtaining a powder by drying and powdering the FEP-containing aqueous fluoropolymer dispersion obtained by the production method of the present invention.

The above-mentioned powders may be fluorinated. The method for producing the fluorinated powder is a method for obtaining a fluorinated powder by supplying fluorine gas to the powder obtained by the method for producing a powder and fluorinating the powder.

The method for producing the FEP pellet is a method for obtaining a pellet by pelletizing the FEP obtained by the production method of the present invention.

The above pellets may be fluorinated. The method for producing fluorinated pellets is a method for obtaining fluorinated pellets by supplying fluorine gas to the pellets obtained by the method for producing pellets and fluorinating the fluorine gas.

Therefore, this FEP can be used for the production of various molded articles such as a coating material for electric wires, foamed electric wires, cables, and wires, and pipes, films, sheets, and filaments.

(2) In the production method of the present invention, it is generally preferable that polymerization of a TFE/perfluoro (alkyl vinyl ether) copolymer such as PFA or MFA and a TFE/perfluoroallyl ether copolymer is carried out at a polymerization temperature of 10 to 100 ℃ and a polymerization pressure of 0.3 to 6.0 MPaG.

The preferred monomer composition (mol%) of the TFE/perfluoro (alkyl vinyl ether) copolymer is TFE: perfluoro (alkyl vinyl ether) ═ 90 to 99.7: (0.3-10), more preferably (97-99): (1-3). As the above perfluoro (alkyl vinyl ether), the formula: CF (compact flash)₂＝CFORf⁴(wherein Rf⁴A perfluoroalkyl group having 1 to 6 carbon atoms).

The preferred monomer composition (mol%) of the TFE/perfluoroallyl ether copolymer is TFE: perfluoro allyl ether ═ (90-99.7): (0.3-10), more preferably (97-99): (1-3). As the above-mentioned perfluoroallyl ether, the compound of the formula: CF (compact flash)₂＝CFCF₂ORf⁴(wherein Rf⁴A perfluoroalkyl group having 1 to 6 carbon atoms).

In the polymerization of the TFE/perfluoro (alkyl vinyl ether) copolymer and the TFE/perfluoroallyl ether copolymer, the surfactant may be used in the range used in the production method of the present invention, and is preferably added in an amount of 0.0001 to 10% by mass, based on 100% by mass of the aqueous medium.

In the polymerization of the TFE/perfluoro (alkyl vinyl ether) copolymer and the TFE/perfluoroallyl ether copolymer, cyclohexane, methanol, ethanol, propanol, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, methyl chloride, methane, ethane, etc. are preferably used as the chain transfer agent, and ammonium carbonate, disodium hydrogen phosphate, etc. are preferably used as the pH buffer.

The aqueous dispersion of the TFE/perfluoro (alkyl vinyl ether) copolymer and TFE/perfluoroallyl ether copolymer obtained by the production method of the present invention, such as PFA and MFA, is subjected to post-treatment such as concentration, and then dried to obtain powder, followed by melt extrusion to obtain pellets. The aqueous medium in the aqueous dispersion may contain an additive such as a nonionic surfactant, and may or may not contain a water-soluble organic solvent such as a water-soluble alcohol.

The melt extrusion may be carried out under any extrusion conditions that can be generally used for producing pellets, and the extrusion conditions may be appropriately set.

The copolymer is preferably treated with a fluorine gas in order to improve its heat resistance and further enhance the effect of suppressing the permeation of a reagent into a molded article.

The fluorine gas treatment is performed by contacting the fluorine gas with a reagent permeation inhibitor. However, since the reaction with fluorine is very exothermic, it is preferable to dilute fluorine with an inert gas such as nitrogen. The amount of fluorine in the fluorine gas/inert gas mixture is 1 to 100 wt%, preferably 10 to 25 wt%. The treatment temperature is 150 to 250 ℃, preferably 200 to 250 ℃, and the fluorine gas treatment time is 3 to 16 hours, preferably 4 to 12 hours. The gas pressure for the fluorine gas treatment is in the range of 1 to 10 atmospheres, and atmospheric pressure is preferably used. When the reactor is used under atmospheric pressure, the fluorine gas/inert gas mixture may be continuously passed through the reactor. As a result, of the above-mentioned copolymer Conversion of unstable terminal to-CF₃Terminal, stable to heat.

As a method for molding the copolymer and the composition thereof, molding methods such as compression molding, transfer molding, extrusion molding, injection molding, blow molding and the like can be applied in the same manner as conventional PFA.

The molding method can provide a desired molded article, and examples of the molded article include a sheet, a film, a gasket, a round bar, a square bar, a tube blank, a tube, a round groove, a square groove, a can, a wafer carrier, a wafer cassette, a beaker, a filter housing, a flowmeter, a pump, a valve, a cock, a socket, a nut, a wire, and a heat-resistant wire.

Among these, the present invention can be suitably used for pipes, tube blanks, tanks, connectors, and the like used in various chemical reaction apparatuses, semiconductor manufacturing apparatuses, acid-based or alkali-based reagent supply apparatuses, and the like, which require impermeability to reagents.

The primer composition can be obtained by further adding a nonionic surfactant to an aqueous dispersion of a TFE/perfluoro (alkyl vinyl ether) copolymer such as PFA or MFA and a TFE/perfluoroallyl ether copolymer, and if necessary, dissolving or dispersing polyethersulfone, polyamideimide and/or polyimide, and metal powder in an organic solvent. It can also be used for the following coating method for coating a metal surface with a fluororesin: the primer composition is applied to a metal surface, a melt-processable fluororesin composition is applied to the primer layer thus formed, and the melt-processable fluororesin composition layer is fired together with the primer layer.

(3) In the production method of the present invention, it is preferable that the polymerization of ETFE is carried out at a polymerization temperature of 10 to 100 ℃ and a polymerization pressure of 0.3 to 2.0 MPaG.

The preferred monomer composition (mol%) of ETFE is TFE: ethylene (50-99): (50-1). Further, the ETFE may be modified by using a 3 rd monomer in an amount of 0 to 20 mass% based on the total monomers. Preferably, TFE: ethylene: a 3 rd monomer ═ (63-94): (27-2): (1-10). As the above-mentioned 3 rd monomer, perfluorobutylethylene, perfluorohexylethylene, 3,4,4,5,5,6,6,7,7,8,8, 8-tridecafluoro-1-octene, 2,3,3,4,4,5, 5-heptafluoro-1-pentene (CH)₂＝CFCF₂CF₂CF₂H) 2-trifluoromethyl-3, 3, 3-trifluoropropene ((CF)₃)₂C＝CH₂)。

In the polymerization of ETFE, the surfactant may be used in the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 10% by mass based on 100% by mass of the aqueous medium.

In the polymerization of ETFE, cyclohexane, methanol, ethanol, propanol, ethane, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, methylene chloride, methyl chloride, or the like is preferably used as a chain transfer agent.

The aqueous dispersion of ETFE obtained by the production method of the present invention may be subjected to post-treatment such as concentration, and then dried to obtain powder, and then melt-extruded to obtain pellets. The aqueous medium in the aqueous dispersion may contain an additive such as a nonionic surfactant, and may or may not contain a water-soluble organic solvent such as a water-soluble alcohol.

The melt extrusion may be carried out under any extrusion conditions that can be generally used for producing pellets, and the extrusion conditions may be appropriately set.

The ETFE sheet may be formed by extrusion molding. That is, ETFE powder or pellets may be melted, continuously extruded through a die, and cooled to obtain a sheet-like molded article. An additive may be added to ETFE.

As the additive, known additives can be suitably used. Specific examples thereof include ultraviolet absorbers, light stabilizers, antioxidants, infrared absorbers, flame retardants, flame-retardant fillers, organic pigments, inorganic pigments, and dyes. From the viewpoint of excellent weather resistance, inorganic additives are preferred.

The content of the additive in the ETFE sheet is preferably 20 mass% or less, and particularly preferably 10 mass% or less, based on the total mass of the ETFE sheet.

Since the ETFE sheet is excellent in mechanical strength and appearance, it is suitable as a film material (such as a roofing material, a ceiling material, an outer wall material, an inner wall material, and a coating material) for a membrane structure building (such as a sports facility, a gardening facility, and an atrium).

In addition, not only the film material of the film structure building, but also the following materials are useful, for example: outdoor use panels (sound-insulating wall, wind fence, wave barrier, garage top, shopping center, pedestrian side wall, roof material), glass scattering prevention film, heat-resistant and water-resistant sheet, building materials (tent material in tent warehouse, film material for sunshade, partial roof material for lighting, window material for glass replacement, film material for fire-proof partition, curtain, outer wall reinforcement, waterproof film, smoke-proof film, flame-retardant transparent partition, road reinforcement, interior decoration (lighting, wall surface, louver, etc.), exterior decoration (screen, signboard, etc.), living and leisure goods (fishing rod, racket, golf club, screen, etc.), automobile materials (hood, damping material, car body, etc.), aircraft materials, ship materials, home appliance exterior, storage tank, container inner wall, filter, construction film material, electronic materials (printed substrate, wiring substrate, etc.), and the like, Insulating film, release film, etc.), a surface material of a solar cell module, a mirror protective material for solar power generation, a surface material of a solar water heater, etc.

(4) The electrolyte polymer precursor can also be produced using the production method of the present invention. In the production method of the present invention, the polymerization of the electrolyte polymer precursor is preferably carried out at a polymerization temperature of 10 to 100 ℃ and a polymerization pressure of 0.1 to 2.0 MPaG. The electrolyte polymer precursor is a substance that contains a vinyl ether monomer as shown below and can be converted into an ion-exchange polymer by hydrolysis treatment.

Examples of the vinyl ether monomer used in the electrolyte polymer precursor include

General formula (150): CF (compact flash)₂＝CF-O-(CF₂CFY¹⁵¹-O)_n-(CFY¹⁵²)_m-A¹⁵¹

(in the formula, Y¹⁵¹Represents a fluorine atom, a chlorine atom or-SO₂F groups or perfluoroalkyl groups. The perfluoroalkyl group may contain etheric oxygen and-SO₂And F group. n tableRepresents an integer of 0 to 3. n number of Y¹⁵¹May be the same or different. Y is¹⁵²Represents a fluorine atom, a chlorine atom or-SO₂And F group. m represents an integer of 1 to 5. m number of Y¹⁵²May be the same or different. A. the¹⁵¹represents-SO₂X¹⁵¹、-COZ¹⁵¹or-POZ¹⁵²Z¹⁵³。X¹⁵¹Represents F, Cl, Br, I, -OR¹⁵¹or-NR¹⁵²R¹⁵³。Z¹⁵¹、Z¹⁵²And Z¹⁵³Identically or differently representing-NR¹⁵⁴R¹⁵⁵OR-OR¹⁵⁶。R¹⁵¹、R¹⁵²、R¹⁵³、R¹⁵⁴、R¹⁵⁵And R¹⁵⁶The same or different represent H, ammonium, an alkali metal, an alkyl group which may contain a fluorine atom, an aryl group or a sulfonyl group-containing group. ) The fluoromonomer is shown. The preferred monomer composition (mol%) of the electrolyte polymer precursor is TFE: vinyl ether (50-99): (50-1), more preferably TFE: vinyl ether (50-93): (50-7).

The electrolyte polymer precursor may be modified with the 3 rd monomer in a range of 0 to 20 mass% of the total monomers. Examples of the 3 rd monomer include polyfunctional monomers such as CTFE, vinylidene fluoride, perfluoroalkyl vinyl ether, and divinylbenzene.

The electrolyte polymer precursor thus obtained can be subjected to hydrolysis with an alkaline solution and treatment with an inorganic acid after being formed into a film shape, for example, and used as a polymer electrolyte membrane for fuel cells, electrolysis devices, redox flow batteries, and the like.

In addition, an electrolyte polymer dispersion can be obtained by performing hydrolysis with an alkali solution while maintaining the dispersion state of the electrolyte polymer precursor.

Then, the mixture is heated to 120 ℃ or higher in a pressurized container and dissolved in, for example, a water/alcohol mixed solvent to be able to be brought into a solution state.

The solution thus obtained can be used as, for example, a binder for an electrode, or can be compounded with various additives and cast into a film for use in, for example, an antifouling coating film, an organic actuator, or the like.

(5) TFE/VDF copolymers

In the production method of the present invention, the polymerization temperature of the TFE/VDF copolymer is not particularly limited, and may be 0 to 100 ℃. The polymerization pressure is appropriately set in accordance with other polymerization conditions such as polymerization temperature, and may be usually 0 to 9.8 MPaG.

The preferred monomer composition (mol%) of the TFE/VDF copolymer is TFE: VDF ═ (5-90): (95-10). The TFE/VDF copolymer may be modified with the use of the 3 rd monomer in a range of 0 to 50 mol% based on the total amount of the monomers. Preferably, TFE: ethylene: a 3 rd monomer ═ (30-85): (10-69.9): (0.1-10).

As the above-mentioned 3 rd monomer, preferred is

Formula (II): CX¹¹X¹²＝CX¹³(CX¹⁴X¹⁵)_n11X¹⁶

(in the formula, X¹¹～X¹⁶The same or different represent H, F or Cl, and n11 represents an integer of 0 to 8. With TFE and VDF excluded. ) The monomer shown, or

Formula (II): CX²¹X²²＝CX²³-O(CX²⁴X²⁵)_n21X²⁶

(in the formula, X²¹～X²⁶The same or different represent H, F or Cl, and n21 represents an integer of 0 to 8. ) Monomers are shown.

In addition, the 3 rd monomer may be a non-fluorine-containing ethylenic monomer. The non-fluorine-containing ethylenic monomer is preferably selected from ethylenic monomers having 6 or less carbon atoms in view of maintaining heat resistance and chemical resistance. Examples thereof include ethylene, propylene, 1-butene, 2-butene, vinyl chloride, vinylidene chloride, alkyl vinyl ethers (methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, etc.), maleic acid, itaconic acid, 3-butenoic acid, 4-pentenoic acid, vinylsulfonic acid, acrylic acid, methacrylic acid, and the like.

In the polymerization of the TFE/VDF copolymer, the surfactant can be used in the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 5% by mass relative to 100% by mass of the aqueous medium.

The amidation treatment may be performed by contacting the TFE/VDF copolymer obtained by polymerization with aqueous ammonia, ammonia gas, or a nitrogen compound that can generate ammonia.

The TFE/VDF copolymer obtained by the above method is preferably used as a raw material for obtaining a TFE/VDF copolymer fiber by a spin draw method. The spinning and drawing method is as follows: a TFE/VDF copolymer was melt-spun, cooled and solidified to obtain an undrawn yarn, and the undrawn yarn was drawn by running through a heated cylindrical body to obtain a TFE/VDF copolymer fiber.

The TFE/VDF copolymer may be dissolved in an organic solvent to obtain a solution of the TFE/VDF copolymer. Examples of the organic solvent include nitrogen-containing organic solvents such as N-methyl-2-pyrrolidone, N-dimethylacetamide, and dimethylformamide; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as tetrahydrofuran and dioxane; and low-boiling-point general-purpose organic solvents such as mixed solvents thereof. The solution can be used as a binder for a battery.

It is also preferable to use a composite porous film obtained by coating an aqueous dispersion of the TFE/VDF copolymer on a porous substrate made of a polyolefin resin. It is also preferable to use a composite porous film obtained by dispersing inorganic particles and/or organic particles in an aqueous dispersion and coating the dispersion on a porous substrate. The composite porous film thus obtained can be used as a separator for a lithium secondary battery or the like.

The powder of the melt-processable fluororesin is suitably used as a powder coating material. When the powder coating material comprising the melt-processable fluororesin powder is applied to a substrate, a coating having a smooth surface can be obtained. The melt-processable fluororesin powder having an average particle diameter of 1 to less than 100 μm is particularly suitable as a powder coating material for use in electrostatic coating, and the melt-processable fluororesin powder having an average particle diameter of 100 to 1000 μm is particularly suitable as a powder coating material for use in spin coating or spin molding.

The melt-processable fluororesin powder can be produced by a method in which an aqueous dispersion of the melt-processable fluororesin obtained by the production method of the present invention is dried to obtain a powder. The method for producing the melt-processable fluororesin powder is also one aspect of the present invention.

(III) fluororubber

In the production method of the present invention, the polymerization of the fluororubber is initiated by charging pure water and the surfactant into a pressure-resistant reaction vessel equipped with a stirrer, deoxidizing, charging the monomer, adjusting to a predetermined temperature, and adding a polymerization initiator. Since the pressure decreases as the reaction proceeds, additional monomer is continuously or intermittently additionally supplied to maintain the initial pressure. When a predetermined amount of the monomer was supplied, the supply was stopped, and the monomer in the reaction vessel was purged to return the temperature to room temperature, thereby terminating the reaction. In this case, the polymer emulsion can be continuously withdrawn from the reaction vessel.

In particular, when a thermoplastic elastomer is produced as the fluororubber, the following method may be used as disclosed in international publication No. 00/01741: the fluoropolymer fine particles are synthesized at a high concentration, and then diluted and further polymerized, whereby the final polymerization rate can be increased as compared with the usual polymerization.

The polymerization of the fluororubber is carried out under conditions selected as appropriate from the viewpoint of controlling the physical properties and polymerization rate of the target polymer, and at a polymerization temperature of usually-20 to 200 ℃, preferably 5 to 150 ℃, and a polymerization pressure of usually 0.5 to 10MPaG, preferably 1 to 7 MPaG. The pH in the polymerization medium is preferably maintained at usually 2.5 to 13 by a known method using a pH adjuster or the like described later.

Examples of the monomer used for the polymerization of the fluororubber include, in addition to vinylidene fluoride, a fluorine-containing ethylenically unsaturated monomer having at least the same number of fluorine atoms as carbon atoms and being copolymerizable with vinylidene fluoride. Examples of the fluorine-containing ethylenically unsaturated monomer include trifluoropropene, pentafluoropropene, hexafluorobutene and octafluorobutene. Among these, hexafluoropropylene is particularly preferred because of the characteristics of the elastomer obtained when it blocks crystal growth of the polymer. Further, examples of the fluorine-containing ethylenically unsaturated monomer include trifluoroethylene, TFE, and CTFE, and 1 or 2 or more kinds of fluorine-containing monomers having a chlorine and/or bromine substituent may be used. Perfluoro (alkyl vinyl ethers), such as perfluoro (methyl vinyl ether), may also be used. TFE and HFP are preferred in the manufacture of fluororubbers.

The preferred monomer composition (mass%) of the fluororubber is vinylidene fluoride: HFP: TFE (20-70): (30-48): (0 to 32). The fluororubbers of this composition exhibit good elastomeric properties, chemical resistance and thermal stability.

In the polymerization of the fluororubber, the surfactant may be used in the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 20% by mass based on 100% by mass of the aqueous medium. Preferably 10% by mass or less, more preferably 2% by mass or less.

In the polymerization of the fluororubber, a known inorganic radical polymerization initiator can be used as a polymerization initiator. As the above inorganic radical polymerization initiator, conventionally known water-soluble inorganic peroxides, for example, persulfates, perphosphates, perborates, percarbonates or permanganates of sodium, potassium and ammonium are particularly useful. The above radical polymerization initiator may be further activated by a reducing agent (e.g., sulfite, bisulfite, metabisulfite, hyposulfite, thiosulfate, phosphite or hypophosphite of sodium, potassium or ammonium), or by a metal compound which is easily oxidized (e.g., ferrous salt, cuprous salt or silver salt). The preferred inorganic radical polymerization initiator is ammonium persulfate, more preferably ammonium persulfate and sodium bisulfite are used simultaneously in a redox system.

The concentration of the polymerization initiator to be added is suitably determined in accordance with the molecular weight of the intended fluoropolymer and the polymerization reaction rate, and is set to 0.0001 to 10% by mass, preferably 0.01 to 5% by mass, based on 100% by mass of the total monomer.

In the polymerization of the above fluororubbersAs the chain transfer agent, a known chain transfer agent can be used, and hydrocarbons, esters, ethers, alcohols, ketones, chlorides, carbonates, and the like can be used, and hydrocarbons, esters, ethers, alcohols, chlorides, iodides, and the like can be used for the thermoplastic elastomer. Of these, acetone and isopropyl alcohol are preferred, isopentane, diethyl malonate and ethyl acetate are preferred from the viewpoint of making it difficult to reduce the reaction rate in the polymerization of a thermoplastic elastomer, and I (CF) is preferred from the viewpoint of enabling iodination of the polymer end and use as a reactive polymer ₂)₄I、I(CF₂)₆I、ICH₂And diiodo compounds such as I.

The amount of the chain transfer agent to be used is usually 0.5X 10 relative to the total amount of the monomers to be supplied^-3～5×10^-3Mol%, preferably 1.0X 10^-3～3.5×10^-3And (3) mol%.

In the polymerization of the fluororubber, paraffin wax or the like can be preferably used as the emulsion stabilizer, and in the polymerization of the thermoplastic elastomer, phosphate, sodium hydroxide, potassium hydroxide or the like can be preferably used as the pH adjuster.

The aqueous dispersion containing a fluororubber obtained by the production method of the present invention has a solid content concentration of 1.0 to 40% by mass, an average particle diameter of 0.03 to 1 μm, preferably 0.05 to 0.5 μm, and a number average molecular weight of 1,000 to 2,000,000 at the time of termination of polymerization.

The aqueous dispersion of fluororubber obtained by the production method of the present invention can be prepared into a dispersion suitable for rubber molding processing by adding a dispersion stabilizer such as a hydrocarbon surfactant, if necessary, and then concentrating the dispersion. The dispersion is subjected to pH adjustment, coagulation, heating, and the like. Each process was performed as follows.

The above pH adjustment includes: adding inorganic acid such as nitric acid, sulfuric acid, hydrochloric acid or phosphoric acid, and/or carboxylic acid having 5 or less carbon atoms and a pKa of 4.2 or less, and adjusting the pH to 2 or less.

The solidification is carried out by adding an alkaline earth metal salt. Examples of the alkaline earth metal salt include nitrates, chlorates and acetates of calcium or magnesium.

The pH adjustment and the coagulation may be performed first, but the pH adjustment is preferably performed first.

After each operation, the rubber was washed with water having the same volume as that of the fluororubber to remove impurities such as a buffer and salts present in a small amount in the fluororubber, and the resulting mixture was dried. Drying is generally performed at about 70 to 200 ℃ in a drying furnace at a high temperature while circulating air.

The fluororubber may be a partially fluorinated rubber or a perfluororubber.

Examples of the partially fluorinated rubber include vinylidene fluoride (VdF) fluororubbers, Tetrafluoroethylene (TFE)/propylene (Pr) fluororubbers, Tetrafluoroethylene (TFE)/propylene/vinylidene fluoride (VdF) fluororubbers, ethylene/Hexafluoropropylene (HFP)/vinylidene fluoride (VdF) fluororubbers, ethylene/Hexafluoropropylene (HFP)/Tetrafluoroethylene (TFE) fluororubbers, and the like. Among them, at least 1 selected from the group consisting of vinylidene fluoride-based fluororubbers and tetrafluoroethylene/propylene-based fluororubbers is preferable.

The vinylidene fluoride-based fluororubber is preferably a copolymer composed of 45 to 85 mol% of vinylidene fluoride and 55 to 15 mol% of at least 1 other monomer copolymerizable with vinylidene fluoride. More preferably 50 to 80 mol% of vinylidene fluoride and 50 to 20 mol% of at least 1 other monomer copolymerizable with vinylidene fluoride.

Examples of the at least 1 other monomer copolymerizable with vinylidene fluoride include tetrafluoroethylene [ TFE ]]Hexafluoropropylene [ HFP ]]Fluoroalkyl vinyl ether, chlorotrifluoroethylene [ CTFE ]]Trifluoroethylene, trifluoropropene, pentafluoropropene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, vinyl fluoride, a compound of the general formula (100): CH (CH)₂＝CFRf¹⁰¹(wherein Rf¹⁰¹A linear or branched fluoroalkyl group having 1 to 12 carbon atoms), a general formula (170): CH (CH)₂＝CH-(CF₂)_n-X¹⁷¹(in the formula, X¹⁷¹Is H or F, and n is an integer of 3-10. ) Monomers such as the fluorine monomer and the monomer providing a crosslinking site; non-fluorinated monomers such as ethylene, propylene, alkyl vinyl ethers, and the like. They can beEither individually or in any combination. Among these, at least 1 selected from the group consisting of TFE, HFP, fluoroalkyl vinyl ether, and CTFE is preferably used. The fluoroalkyl vinyl ether is preferably a fluorine monomer represented by general formula (160).

Specific examples of the vinylidene fluoride-based fluororubber include VdF/HFP-based rubbers, VdF/HFP/TFE-based rubbers, VdF/CTFE/TFE-based rubbers, VdF/fluoromonomer-based rubbers represented by the general formula (100), VdF/fluoromonomer-TFE-based rubbers represented by the general formula (100), VdF/perfluoro (methyl vinyl ether) [ PMVE ] ]And VDF/PMVE/TFE rubber, VDF/PMVE/TFE/HFP rubber, and the like. VDF/the fluoromonomer rubber represented by the general formula (100) is preferably VDF/CH₂＝CFCF₃The rubber is VDF/fluoromonomer/TFE rubber represented by the general formula (100), preferably VDF/TFE/CH₂＝CFCF₃Is a rubber.

The above VDF/CH₂＝CFCF₃The rubber is preferably composed of VDF 40-99.5 mol% and CH₂＝CFCF₃0.5 to 60 mol% of a copolymer, more preferably VDF50 to 85 mol% and CH₂＝CFCF₃20 to 50 mol% of a copolymer.

The tetrafluoroethylene/propylene-based fluororubber is preferably a copolymer comprising 45 to 70 mol% of tetrafluoroethylene, 55 to 30 mol% of propylene, and 0 to 5 mol% of a fluorine monomer that provides a crosslinking site.

The fluororubber may be a perfluororubber. As the above-mentioned perfluororubber, a perfluororubber containing TFE is preferable, and for example, at least 1 selected from the group consisting of TFE/fluoromonomer copolymer represented by the general formula (160), (130) or (140) and TFE/fluoromonomer represented by the general formula (160), (130) or (140)/monomer copolymer providing a crosslinking site is preferable.

As for the composition, in the case of TFE/PMVE copolymer, it is preferably 45 to 90/10 to 55 mol%, more preferably 55 to 80/20 to 45, and still more preferably 55 to 70/30 to 45.

In the case of a TFE/PMVE/crosslinking site-providing monomer copolymer, the ratio is preferably 45 to 89.9/10 to 54.9/0.01 to 4 (mol%), more preferably 55 to 77.9/20 to 49.9/0.1 to 3.5, and still more preferably 55 to 69.8/30 to 44.8/0.2 to 3.

In the case of TFE/fluoromonomer copolymer represented by general formula (160), (130) or (140) having 4 to 12 carbon atoms, it is preferably 50 to 90/10 to 50 mol%, more preferably 60 to 88/12 to 40, and still more preferably 65 to 85/15 to 35.

In the case of TFE/a fluorine monomer represented by the general formula (160), (130) or (140) having 4 to 12 carbon atoms/a monomer copolymer providing a crosslinking site, the amount is preferably 50 to 89.9/10 to 49.9/0.01 to 4 (mol%), more preferably 60 to 87.9/12 to 39.9/0.1 to 3.5, and still more preferably 65 to 84.8/15 to 34.8/0.2 to 3.

When the amount is outside the range of the above composition, the properties as a rubber elastomer are lost, and the properties tend to be close to those of a resin.

The perfluoro rubber is preferably at least 1 selected from the group consisting of a TFE/fluoromonomer represented by the general formula (140)/fluoromonomer copolymer providing a crosslinking site, a TFE/perfluorovinyl ether copolymer represented by the general formula (140), a TFE/fluoromonomer copolymer represented by the general formula (160) and a TFE/fluoromonomer represented by the general formula (160)/fluoromonomer copolymer providing a crosslinking site.

Examples of the above-mentioned perfluoro rubber include perfluoro rubbers described in International publication No. 97/24381, Japanese patent publication No. 61-57324, Japanese patent publication No. 4-81608, and Japanese patent publication No. 5-13961.

The glass transition temperature of the fluororubber is preferably-70 ℃ or higher, more preferably-60 ℃ or higher, and still more preferably-50 ℃ or higher, from the viewpoint of excellent compression set at high temperatures. From the viewpoint of good cold resistance, it is preferably 5 ℃ or lower, more preferably 0 ℃ or lower, and still more preferably-3 ℃ or lower.

The glass transition temperature can be determined as follows: a DSC curve was obtained by heating 10mg of a sample at 10 ℃/min using a differential scanning calorimeter (DSC 822e, manufactured by Mettler Toredo corporation), and the temperature of the midpoint of 2 intersections where an extension line of a base line before and after the secondary phase transition of the DSC curve intersects a tangent line at the inflection point of the DSC curve was obtained as the glass transition temperature.

In the fluororubber, the mooney viscosity ML (1+20) at 170 ℃ is preferably 30 or more, more preferably 40 or more, and still more preferably 50 or more, from the viewpoint of good heat resistance. From the viewpoint of good workability, it is preferably 150 or less, more preferably 120 or less, and still more preferably 110 or less.

In the fluororubber, the mooney viscosity ML (1+20) at 140 ℃ is preferably 30 or more, more preferably 40 or more, and still more preferably 50 or more, from the viewpoint of good heat resistance. From the viewpoint of good workability, it is preferably 180 or less, more preferably 150 or less, and further preferably 110 or less.

In the fluororubbers, the mooney viscosity ML (1+10) at 100 ℃ is preferably 10 or more, more preferably 20 or more, and still more preferably 30 or more, from the viewpoint of good heat resistance. From the viewpoint of good workability, the amount is preferably 120 or less, more preferably 100 or less, and still more preferably 80 or less.

The Mooney viscosity can be measured at 170 ℃ or 140 ℃ and 100 ℃ in accordance with JIS K6300 using a Mooney viscometer model MV2000E manufactured by ALPHATECHNOLOGIES.

The aqueous dispersion of the fluororubber obtained by the production method of the present invention may be used in the form of a gum mass (gum) or a briquette (crumbb) obtained by coagulation, drying, or the like by a conventionally known method. The surfactant used in the production method of the present invention can improve the stability of the aqueous dispersion, and is more preferably used in the polymerization method in which a sparingly water-soluble substance such as an initiator such as an organic peroxide or a chain transfer agent such as iodine or a bromine compound is added during the polymerization as described above.

The gum mass (gum) is a granular small mass made of fluororubber, and the agglomerates (crumbs) are formed in a form in which the fluororubber cannot retain the granular shape as gum mass at room temperature and fuse with each other, resulting in an amorphous block.

The fluororubber may be processed into a fluororubber composition by adding a curing agent, a filler, or the like.

Examples of the curing agent include polyhydric alcohols, polyamines, organic peroxides, organotin, bis (aminophenol) tetramine, bis (thioaminophenol), and the like.

The fluororubber composition is composed of the fluororubber, and therefore contains substantially no emulsifier, and is excellent in that it is easily crosslinked during molding.

By molding the fluororubber, a fluororubber molded product can be obtained. The method of the molding process is not particularly limited, and known methods using the curing agent can be mentioned.

The fluororubber molded article is suitable for use as a sealing material, a gasket, an electric wire coating, a hose, a pipe, a laminate, a decorative article, etc., and is particularly suitable for use as a component for a semiconductor manufacturing apparatus, an automobile component, etc.

Examples of the hydrocarbon-based surfactant used for producing the fluoropolymer include the hydrocarbon-based surfactants described in Japanese patent application laid-open Nos. 2013-542308, 2013-542309, and 2013-542310.

The hydrocarbon surfactant may be a surfactant having a hydrophilic portion and a hydrophobic portion on the same molecule. These surfactants may be cationic, nonionic or anionic.

Cationic hydrocarbon surfactants generally have a positively charged hydrophilic moiety such as an alkylated ammonium halide, e.g., an alkylated ammonium bromide, and a hydrophobic moiety such as a long-chain fatty acid.

The anionic hydrocarbon surfactant generally has a hydrophilic portion such as carboxylate, sulfonate or sulfate and a hydrophobic portion such as alkyl as a long-chain hydrocarbon portion.

The nonionic hydrocarbon surfactant generally contains no charged group and has a hydrophobic portion as a long-chain hydrocarbon. The hydrophilic portion of the nonionic hydrocarbon surfactant contains a water-soluble functional group such as a vinyl ether chain derived by polymerization with ethylene oxide.

Examples of nonionic Hydrocarbon-based surfactants

Polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerol esters, and derivatives thereof.

Specific examples of polyoxyethylene alkyl ethers: polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, and the like.

Specific examples of polyoxyethylene alkylphenyl ethers: polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and the like.

Specific examples of polyoxyethylene alkyl esters: polyethylene glycol monolaurate, polyethylene glycol monooleate, polyethylene glycol monostearate, and the like.

Specific examples of sorbitan alkyl esters: polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and the like.

Specific examples of polyoxyethylene sorbitan alkyl esters: polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and the like.

Specific examples of glycerides: glyceryl monomyristate, glyceryl monostearate, glyceryl monooleate, etc.

Specific examples of the above derivatives: polyoxyethylene alkylamines, polyoxyethylene alkylphenyl-formaldehyde condensates, polyoxyethylene alkyl ether phosphates, and the like.

The ethers and esters may have an HLB value of 10 to 18.

Examples of the nonionic hydrocarbon surfactant include Triton (registered trademark) X series (X15, X45, X100, etc.), Tergitol (registered trademark) 15-S series, Tergitol (registered trademark) TMN series (TMN-6, TMN-10, TMN-100, etc.), Tergitol (registered trademark) L series, Pluronic (registered trademark) R series (31R1, 17R2, 10R5, 25R4(m to 22, n to 23), and Iconol (registered trademark) TDA series (TDA-6, TDA-9, TDA-10), which are manufactured by Dow chemical Co., Ltd.

Examples of the anionic hydrocarbon surfactant include Versatic (registered trademark) 10 from Resolution Performance Products, and Avanel S series (S-70, S-74, etc.) manufactured by BASF corporation.

Examples of the anionic hydrocarbon surfactant include R-L-M (wherein R represents a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent, and when the number of carbon atoms is 3 or more, a heterocyclic ring having 1 or 2 valences may be included, or a ring may be formed)₃ ^-、-SO₃ ^-、-SO₄-、-PO₃ ^-or-COO^-M is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁵Is H or an organic radical, -ArSO₃ ^-Is an aryl sulfonate. ) The anionic surfactant is represented. R⁵Preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms.

Specifically, there may be mentioned CH represented by lauric acid, lauryl sulfuric acid (lauryl sulfuric acid) and the like₃-(CH₂)_nL-M (wherein n is an integer of 6 to 17, and L and M are the same as described above).

A mixture of a substance in which R is an alkyl group having 12 to 16 carbon atoms and L-M is a sulfate may also be used.

Examples of the anionic hydrocarbon surfactant include R⁶(-L-M)₂(in the formula, R⁶The alkylene group may be a linear or branched alkylene group having 1 or more carbon atoms, which may have a substituent, or a cyclic alkylene group having 3 or more carbon atoms, which may have a substituent, and may contain a heterocyclic ring having 1 or 2 valences when the number of carbon atoms is 3 or more, or may form a ring. L is-ArSO₃ ^-、-SO₃ ^-、-SO₄-、-PO₃ ^-or-COO^-，M is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁵Is H or an organic radical, -ArSO₃ ^-Is an aryl sulfonate. ) The anionic surfactant is represented.

Examples of the anionic hydrocarbon surfactant include R⁷(-L-M)₃(in the formula, R⁷The alkylene group may be a linear or branched alkylene group having 1 or more carbon atoms, which may have a substituent, or a cyclic alkylene group having 3 or more carbon atoms, which may have a substituent, and may contain a heterocyclic ring having 1 or 2 valences or may form a ring when the number of carbon atoms is 3 or more. L is-ArSO ₃ ^-、-SO₃ ^-、-SO₄-、-PO₃ ^-or-COO^-，M is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁵Is H or an organic group. -ArSO₃ ^-Is an aryl sulfonate. ) The anionic surfactant is represented.

As R⁵Preferably, H or an alkyl group, more preferably H or an alkyl group having 1 to 10 carbon atoms, and still more preferably H or an alkyl group having 1 to 4 carbon atoms.

In the present specification, unless otherwise specified, "substituent" means a group which can be substituted. Examples of the "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl oxy group, a sulfamoyl group, an aliphatic sulfonamide group, an aromatic sulfonamide group, a heterocyclic sulfonamide group, an amino group, an aliphatic amino group, an aromatic amino group, a heterocyclic amino group, an aliphatic oxycarbonylamino group, an aromatic oxycarbonylamino group, a heterocyclic oxycarbonylamino group, an aliphatic sulfinyl group, an aromatic sulfinyl group, an aliphatic thio group, an aromatic thio group, a hydroxyl group, a cyano group, a sulfo group, a carboxyl group, an aliphatic oxyamino group, an aromatic oxyamino group, a carbamoylamino group, Sulfamoylamino, a halogen atom, sulfamoylcarbamoyl, carbamoylsulfamoyl, dialiphatic oxyphosphinyl or diaromatic oxyphosphinyl.

The hydrocarbon surfactant may be a siloxane hydrocarbon surfactant. Examples of the Silicone hydrocarbon surfactant include Silicone Surfactants, r.m. hill, Marcel Dekker, inc., ISBN: 0 to 8247-00104. The structure of siloxane hydrocarbon-based surfactants contains well-defined hydrophobic and hydrophilic portions. The hydrophobic moiety comprises 1 or more dihydrocarbylsiloxane units, where the substituents on the siloxane atoms are entirely hydrocarbons.

These siloxane hydrocarbon surfactants can also be considered to be hydrocarbon surfactants in the sense that when the carbon atom of the dihydrocarbyl group may be substituted with a halogen such as fluorine, the substitution is completely with a hydrogen atom, i.e., the monovalent substituent on the carbon atom of the dihydrocarbyl group is hydrogen.

The hydrophilic moiety of the siloxane hydrocarbon surfactant may include 1 or more polar moieties containing ionic groups, such as sulfate ester, sulfonate ester, phosphonate ester, phosphate ester, carboxylate ester, carbonate ester, sulfosuccinate ester, taurine (salt/ester) (in the form of a free acid, salt, or ester), phosphine oxide, betaine copolyol, and quaternary ammonium salt. The ionic hydrophobic moiety may also comprise an ionic functionalized silicone graft.

Examples of such silicone hydrocarbon surfactants include polydimethylsiloxane-graft- (meth) acrylate, polydimethylsiloxane-graft-polyacrylate, and polydimethylsiloxane-grafted quaternary amine.

The polar portion of the hydrophilic portion of the silicone hydrocarbon surfactant may include polyethers such as polyethylene oxide (PEO), mixed polyethylene oxide/propylene oxide polyether (PEO/PPO), and the like; monosaccharides and disaccharides; and a nonionic group formed from a water-soluble heterocyclic ring such as pyrrolidone. The ratio of ethylene oxide to propylene oxide (EO/PO) is variable in the mixed polyethylene oxide/propylene oxide polyether.

The hydrophilic portion of the siloxane hydrocarbon surfactant may also comprise a combination of ionic and nonionic moieties. Examples of such moieties include ionic end-functionalized or randomly functionalized polyethers or polyols. Preferred for the practice of the present invention are silicones having a nonionic portion, i.e., nonionic silicone hydrocarbon-based surfactants.

The arrangement of the hydrophobic portion and the hydrophilic portion of the structure of the silicone hydrocarbon surfactant may take the form of a diblock polymer (AB), a triblock polymer (ABA) (here, "B" represents the silicone portion of the molecule), or a multiblock polymer. Alternatively, the silicone surfactant may comprise a graft polymer.

Siloxane hydrocarbon surfactants are also disclosed in U.S. Pat. No. 6,841,616.

Examples of the siloxane-based anionic hydrocarbon surfactant include SilSense available from Noveon (registered trademark) Consumer Specialties of Lubrizol Advanced Materials, Inc^TMPE-100 siloxane, SilSense^TMCA-1 siloxane, and the like.

Examples of the anionic hydrocarbon surfactant include Lankropol (registered trademark) K8300, which is a sulfosuccinate surfactant from Akzo Nobel Surface Chemistry LLC.

Examples of the sulfosuccinate surfactant include diisodecyl sulfosuccinate Na salt, (Emulsogen (registered trademark) SB10 from Clariant), diisotridecyl sulfosuccinate Na salt (Polirol (registered trademark) TR/LNA from Cesapini Chemicals), and the like.

As the above-mentioned hydrocarbon-based surfactant, a PolyFox (registered trademark) surfactant (PolyFox) by Omnova Solutions, inc^TMPF-156A、PolyFoX^TMPF-136A, etc.).

The hydrocarbon surfactant is preferably an anionic hydrocarbon surfactant. As the anionic hydrocarbon surfactant, the above anionic hydrocarbon surfactant can be used, and for example, the following hydrocarbon surfactants can be preferably used.

Examples of the anionic hydrocarbon surfactant include those represented by the following formula (α):

R¹⁰-COOM (α)

(in the formula, R¹⁰Is a 1-valent organic group containing 1 or more carbon atoms. M is H, a metal atom, NR¹¹ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r¹¹Are H or organic radicals, which may be identical or different. ) The compound (. alpha.) shown. As R¹¹Preferably H or C_1-10More preferably H or C_1-4An organic group of (2).

From the aspect of surface active energy, R¹⁰The number of carbon atoms of (b) is preferably 2 or more, more preferably 3 or more. In addition, from the aspect of water solubility, R¹⁰The number of carbon atoms of (b) is preferably 29 or less, more preferably 23 or less.

Examples of the metal atom of M include alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable. M is preferably H, a metal atom or NR¹¹ ₄More preferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR¹¹ ₄Further, H, Na, K, Li or NH is preferable₄Further more preferably Na, K or NH₄Particularly preferred is Na or NH₄Most preferably NH₄。

As the above-mentioned compound (. alpha.), R is also exemplified¹²-COOM (wherein R ¹²The alkyl group may be a linear or branched alkyl, alkenyl, alkylene or alkenylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl, alkenyl, alkylene or alkenylene group having 3 or more carbon atoms which may have a substituent, and these groups may contain an ether bond. When the number of carbon atoms is 3 or more, a heterocyclic ring having a valence of 1 or 2 may be included, or a ring may be formed. M is the same as above. ) The anionic surfactant is represented.

Specifically, canTo give an example of CH₃-(CH₂)_n-COOM (wherein n is an integer of 2 to 28, and M is the same as above).

From the viewpoint of emulsion stability, the anionic hydrocarbon surfactant may not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

The anionic hydrocarbon surfactant containing no carbonyl group preferably includes, for example, the following formula (a): R-COO-M (A) (wherein R is an alkyl group, an alkenyl group, an alkylene group or an alkenylene group, which may contain an ether bond; M is H, a metal atom, NR¹¹ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. R¹¹The same or different are H or organic groups with 1-10 carbon atoms. ) The compound of (1).

In the above formula (a), R is preferably an alkyl group or an alkenyl group (these groups may contain an ether group). The alkyl group or alkenyl group in the above-mentioned R may be linear or branched. The number of carbon atoms of R is not limited, but is, for example, 2 to 29, preferably 4 to 29.

The alkyl, alkenyl, alkylene or alkenylene group in R preferably does not contain a carbonyl group (excluding the carbonyl group in the ester group).

When the alkyl group is linear, the number of carbon atoms in R is preferably 3 to 29, more preferably 5 to 23. When the alkyl group is branched, the number of carbon atoms in R is preferably 5 to 35, more preferably 11 to 23.

When the alkenyl group is linear, the number of carbon atoms of R is preferably 2 to 29, more preferably 9 to 23. When the alkenyl group is branched, the number of carbon atoms in R is preferably 2 to 29, more preferably 3 to 29, and still more preferably 9 to 23.

Examples of the alkyl group and the alkenyl group include a methyl group, an ethyl group, an isobutyl group, a tert-butyl group, and a vinyl group.

Examples of the anionic hydrocarbon surfactant include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, (9,12,15) -linolenic acid, (6,9,12) linolenic acid, elaeostearic acid, arachidic acid, 8, 11-eicosadienoic acid, melissic acid, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, crotonic acid, myristoleic acid, palmitoleic acid, hexadecenoic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, alpha-eleostearic acid, beta-eleostearic acid, oleic acid, and linoleic acid, Melissic acid, dihomo-gamma-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenalic acid, bospentenoic acid, eicosapentaenoic acid, all-cis-4, 7,10,13, 16-docosapentaenoic acid (osbond acid), Spragic acid (Clonanodonic acid), tetracosapentaenoic acid, docosahexaenoic acid, all-cis-6, 9,12,15,18, 21-tetracosahexaenoic acid, and salts thereof.

Particularly preferably at least 1 selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecanoic acid, palmitic acid, and salts thereof, more preferably lauric acid and salts thereof, particularly preferably salts of lauric acid, and most preferably sodium laurate or ammonium laurate.

Examples of the salt include a metal atom having a carboxyl group and a hydrogen atom of the formula M, NR¹¹ ₄The material is not particularly limited, and may be imidazolium, pyridinium or phosphonium.

The hydrocarbon surfactant preferably includes the following general formula (1-0):

[ solution 18]

(in the formula, R¹～R⁵Represents H or a monovalent substituent, wherein R¹And R³At least 1 of them represents a general formula: -Y-R⁶A group shown, R²And R⁵At least 1 of (a) representsA compound of the general formula: -X-A or a group of formula: -Y-R⁶The groups shown.

In addition, X, which may be the same or different at each occurrence, represents a 2-valent linking group or bond;

a may be the same or different at each occurrence and represents-COOM, -SO₃M or-OSO₃M (M is H, metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R ⁷Is H or an organic group);

y may be the same or different at each occurrence and represents a group selected from-S (═ O)₂-、-O-、-COO-、-OCO-、-CONR⁸-and-NR⁸2-valent linking groups or bonds in the group consisting of CO-, R⁸Represents H or an organic group;

R⁶the alkyl group having 1 or more carbon atoms, which may be the same or different at each occurrence, may include at least 1 selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group between carbon-carbon atoms.

R¹～R⁵Any 2 of them may be bonded to each other to form a ring. ) The surfactant shown (hereinafter also referred to as surfactant (1-0)).

The surfactant (1-0) will be described.

In the formula, R¹～R⁵Represents H or a monovalent substituent, wherein R¹And R³At least 1 of them represents a general formula: -Y-R⁶A group shown, R²And R⁵At least 1 of them represents a general formula: -X-A or a group of formula: -Y-R⁶The groups shown. R¹～R⁵Any 2 of them may be bonded to each other to form a ring.

As R¹The substituent which the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

As R¹Preferably said alkyl group of (a) does not comprise carbonyl And (4) a base.

In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

The above alkyl group preferably does not have any substituent.

As R¹The alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not have a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not have a substituent, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not include a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not include a carbonyl group, further preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not have a substituent, further more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, which may or may not have a substituent, and particularly preferably a methyl group (-CH)₃) Or ethyl (-C)₂H₅) Most preferred is methyl (-CH)₃)。

As monovalent substituents, preference is given to those of the formula: -Y-R⁶A group represented by the general formula: a group represented by-X-A, -H, C with or without a substituent_1-20Alkyl, -NH of₂、-NHR⁹(R⁹Is an organic radical), -OH, -COOR ⁹(R⁹Is an organic group) OR-OR⁹(R⁹Is an organic group). The number of carbon atoms of the alkyl group is preferably 1 to 10.

As R⁹Preferably C_1-10Alkyl or C_1-10Alkylcarbonyl of (a), more preferably C_1-4Alkyl or C_1-4An alkylcarbonyl group of (a).

Wherein X, which may be the same or different at each occurrence, represents a 2-valent linking group or a bonding bond.

At R⁶In the case where any one of a carbonyl group, an ester group, an amide group, and a sulfonyl group is not included, X preferably includes a 2-valent linking group of at least 1 selected from the group consisting of a carbonyl group, an ester group, an amide group, and a sulfonyl group.

AsX, preferably comprises a substituent selected from the group consisting of-CO-, -S (═ O)₂-、-O-、-COO-、-OCO-、-S(＝O)₂-O-、-O-S(＝O)₂-、-CONR⁸-and-NR⁸2-valent linking group of at least 1 bond in the group consisting of CO-, C_1-10Alkylene or a bond of (a). R⁸Represents H or an organic group.

As R⁸Preferably H or C_1-10More preferably H or C_1-4The organic group of (3), is more preferably H.

Wherein A may be the same or different at each occurrence and represents-COOM, -SO₃M or-OSO₃M (M is H, metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁷Is H or an organic group. 4R⁷May be the same or different. ). In the general formula (1-0), A is-COOM in one preferred embodiment.

As R⁷Preferably H or C_1-10More preferably H or C_1-4An organic group of (2).

Examples of the metal atom include alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable.

M is preferably H, a metal atom or NR⁷ ₄More preferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR⁷ ₄Further, H, Na, K, Li or NH is preferable₄Further more preferably Na, K or NH₄Particularly preferred is Na or NH₄Most preferably NH₄。

Wherein Y, which may be the same or different at each occurrence, is selected from the group consisting of-S (═ O)₂-、-O-、-COO-、-OCO-、-CONR⁸-and-NR⁸2-valent linking groups or bonds in the group consisting of CO-, R⁸Represents H or an organic group.

Y is preferably a bond selected from the group consisting of-O-, -COO-, -OCO-, -CONR⁸-and-NR⁸A 2-valent linking group in the group consisting of CO-, more preferably a binding bond, a 2-valent linking group selected from the group consisting of-COO-and-OCO-)A linking group.

As R⁸Preferably H or C_1-10More preferably H or C_1-4The organic group of (3), is more preferably H.

In the formula, R⁶The alkyl group may be the same or different at each occurrence and represents an alkyl group having 1 or more carbon atoms which may contain at least 1 selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group between carbon-carbon atoms. R is as defined above ⁶The organic group (2) preferably has 2 or more carbon atoms, preferably 20 or less carbon atoms, more preferably 2 to 20 carbon atoms, and still more preferably 2 to 10 carbon atoms.

At R⁶When the number of carbon atoms of the alkyl group of (2) or more is 2 or more, at least 1 selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group may be contained between carbon-carbon atoms, but these groups are not contained at both terminals of the alkyl group. R is as defined above⁶In the alkyl group (b), 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R⁶Preference is given to

A compound of the general formula: -R¹⁰-CO-R¹¹The group shown,

A compound of the general formula: -R¹⁰-COO-R¹¹The group shown,

A compound of the general formula: -R¹¹The group shown,

A compound of the general formula: -R¹⁰-NR⁸CO-R¹¹A group shown, or

A compound of the general formula: -R¹⁰-CONR⁸-R¹¹A group shown

(in the formula, R⁸Represents H or an organic group. R¹⁰Is alkylene, R¹¹Alkyl with or without substituents).

As R⁶More preferred is the general formula: -R¹⁰-CO-R¹¹The groups shown.

As R⁸Preferably H or C_1-10Of (2) aRadical, more preferably H or C_1-4The organic group of (3), is more preferably H.

R¹⁰The number of carbon atoms of the alkylene group(s) is preferably 1 or more, more preferably 3 or more, preferably 20 or less, more preferably 12 or less, still more preferably 10 or less, and particularly preferably 8 or less. In addition, R ¹⁰The alkylene group (B) preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and further preferably 3 to 10 carbon atoms.

R¹¹The alkyl group (b) may have 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 10 carbon atoms, yet more preferably 1 to 8 carbon atoms, particularly preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms, particularly preferably 1 or 2 carbon atoms, and most preferably 1 carbon atom. In addition, the above R¹¹The alkyl group (b) preferably consists only of a primary carbon, a secondary carbon and a tertiary carbon, and particularly preferably consists only of a primary carbon and a secondary carbon. I.e. as R¹¹Methyl, ethyl, n-propyl and isopropyl are preferred, and methyl is particularly preferred.

In the general formula (1-0), R²And R⁵At least 1 of which is of the general formula: a group represented by-X-A, wherein A is-COOM, is also one of the preferred modes.

As the surfactant (1-0), a compound represented by the general formula (1-1), a compound represented by the general formula (1-2) or a compound represented by the general formula (1-3) is preferable, and a compound represented by the general formula (1-1) or a compound represented by the general formula (1-2) is more preferable.

General formula (1-1):

[ solution 19]

(in the formula, R³～R⁶X, A and Y are as described above. )

General formula (1-2):

[ solution 20]

(in the formula, R⁴～R⁶X, A and Y are as described above. )

General formula (1-3):

[ solution 21]

(in the formula, R²、R⁴～R⁶X, A and Y are as described above. )

As a general formula: a group represented by-X-A, preferably

-COOM、

-R¹²COOM、

-SO₃M、

-OSO₃M、

-R¹²SO₃M、

-R¹²OSO₃M、

-OCO-R¹²-COOM、

-OCO-R¹²-SO₃M、

-OCO-R¹²-OSO₃M

-COO-R¹²-COOM、

-COO-R¹²-SO₃M、

-COO-R¹²-OSO₃M、

-CONR⁸-R¹²-COOM、

-CONR⁸-R¹²-SO₃M、

-CONR⁸-R¹²-OSO₃M、

-NR⁸CO-R¹²-COOM、

-NR⁸CO-R¹²-SO₃M、

-NR⁸CO-R¹²-OSO₃M、

-OS(＝O)₂-R¹²-COOM、

-OS(＝O)₂-R¹²-SO₃M, or

-OS(＝O)₂-R¹²-OSO₃M

(in the formula, R⁸And M is as described above. R¹²Is C_1-10An alkylene group of (a). ).

R is as defined above¹²The alkylene group of (2) may have 75% or less of hydrogen atoms bonded to carbon atoms substituted with halogen atoms, 50% or less of hydrogen atoms substituted with halogen atoms, or 25% or less of hydrogen atoms substituted with halogen atoms, and is preferably a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or chlorine atom.

As a general formula: -Y-R⁶The radicals indicated are preferred

A compound of the general formula: -R¹⁰-CO-R¹¹The group shown,

A compound of the general formula: -OCO-R¹⁰-CO-R¹¹The group shown,

A compound of the general formula: -COO-R¹⁰-CO-R¹¹The group shown,

A compound of the general formula: -OCO-R¹⁰-COO-R¹¹The group shown,

A compound of the general formula: -COO-R¹¹The group shown,

A compound of the general formula: -NR⁸CO-R¹⁰-CO-R¹¹A group shown, or

A compound of the general formula: -CONR⁸-R¹⁰-NR⁸CO-R¹¹A group shown

(in the formula, R⁸、R¹⁰And R¹¹As described above. ).

In the formula, as R⁴And R⁵Preferably independently H or C_1-4Alkyl group of (1).

R is as defined above⁴And R⁵In the alkyl group (b), 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R in the general formula (1-1)³Preferably H or C with or without substituents _1-20More preferably H or C having no substituent_1-20The alkyl group of (3) is more preferably H.

R is as defined above³In the alkyl group (b), 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R in the general formula (1-3)²Preferably H, OH or C with or without substituents_1-20More preferably H, OH or C having no substituent_1-20Further, the alkyl group of (1) is preferably H or OH.

R is as defined above²In the alkyl group (b), 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The hydrocarbon surfactant may be represented by the following formula (1-0A):

[ solution 22]

(in the formula, R^1A～R^5AIs H, a 1-valent hydrocarbon group which may contain an ester group between carbon-carbon atoms, or a compound of the formula: -X^A-A is a group represented by. Wherein R is^2AAnd R^5AAt least 1 of them represents a general formula: -X^A-A is a group represented by.

X^AMay be the same or different in each occurrence and represents a 2-valent hydrocarbyl group or a bond;

A may be the same or different at each occurrence and represents-COOM (M is H, a metal atom, NR)⁷ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R⁷Is H or an organic group);

R^1A～R^5Aany 2 of them may be bonded to each other to form a ring. ) The surfactant (1-0A) shown below, and the like.

In the general formula (1-0A), R^1A～R^5AThe number of carbon atoms of the 1-valent hydrocarbon group which may have an ester group between carbon-carbon atoms in (1) is preferably 1 to 50, more preferably 5 to 20. R^1A～R^5AAny 2 of them may be bonded to each other to form a ring. The above-mentioned 1-valent hydrocarbon group which may contain an ester group between carbon and carbon atoms is preferably an alkyl group.

In the formula, X^AThe number of carbon atoms of the 2-valent hydrocarbon group in (1) to (50), more preferably (5) to (20). Examples of the above-mentioned 2-valent hydrocarbon group include an alkylene group and an alkanediyl group, and an alkylene group is preferable.

In the general formula (1-0A), R is preferred^2AAnd R^5AAny of the above general formulas: -X^AA group represented by-A, more preferably R^2AIs represented by the general formula: -X^A-A is a group represented by.

In the general formula (1-0A), R is a preferable embodiment^2AIs represented by the general formula: -X^AA group represented by-A, R^1A、R^3A、R^4AAnd R^5AIn the form of H. In this case, X^APreferably a bond or an alkylene group having 1 to 5 carbon atoms.

In the general formula (1-0A), the following is also preferable: r^2AIs represented by the general formula: -X^AA group represented by-A, R^1AAnd R^3Ais-Y^A-R⁶A group shown, Y^AWhich in each occurrence may be the same or different and is-COO-, -OCO-or a bond, R⁶The alkyl group may be the same or different at each occurrence and has 1 or more carbon atoms. In this case, R^4AAnd R^5APreferably H.

Examples of the hydrocarbon-based surfactant represented by the general formula (1-0A) include glutaric acid or a salt thereof, adipic acid or a salt thereof, pimelic acid or a salt thereof, suberic acid or a salt thereof, azelaic acid or a salt thereof, sebacic acid or a salt thereof, and the like.

The aliphatic carboxylic acid type hydrocarbon surfactant represented by the general formula (1-0A) may be a double-chain amphiphilic synthetic surfactant, and examples of the Gemini (Gemini) type surfactant include gemsrf (available from seiko corporation), gemsrf α 142 (c 12 lauryl), gemsrf α 102 (c 10), and gemsrf α 182 (c 14).

Further, the hydrocarbon surfactant may include one having 1 or more carbonyl groups (excluding the carbonyl group in the carboxyl group).

Further, a hydrocarbon surfactant obtained by subjecting the above-mentioned hydrocarbon surfactant having 1 or more carbonyl groups (excluding the carbonyl group in the carboxyl group) to radical treatment or oxidation treatment may be used.

The radical treatment may be a treatment for generating a radical in a hydrocarbon surfactant having 1 or more carbonyl groups (excluding a carbonyl group in a carboxyl group), and may be, for example, the following treatment: adding deionized water and hydrocarbon surfactant into a reactor, sealing the reactor, replacing the inside of the system with nitrogen, heating and pressurizing the reactor, adding a polymerization initiator, stirring for a certain time, depressurizing the reactor until the atmospheric pressure is reached, and cooling. The oxidation treatment is a treatment in which an oxidizing agent is added to a hydrocarbon surfactant having 1 or more carbonyl groups (excluding a carbonyl group in a carboxyl group). Examples of the oxidizing agent include oxygen, ozone, hydrogen peroxide, manganese (IV) oxide, potassium permanganate, potassium dichromate, nitric acid, and sulfur dioxide. In order to promote the radical treatment or the oxidation treatment, the radical treatment or the oxidation treatment may be performed in an aqueous solution in which the pH is adjusted. The pH of the aqueous solution for the radical treatment or the oxidation treatment is preferably less than 7, and the pH of the aqueous solution can be adjusted using, for example, sulfuric acid, nitric acid, hydrochloric acid, or the like.

As the above-mentioned hydrocarbon-based surfactant having 1 or more carbonyl groups (excluding carbonyl groups in carboxyl groups), preferred is a surfactant of the formula: R-X (wherein R is a non-fluorine-containing organic group having 1 or more carbonyl groups (excluding a carbonyl group in a carboxyl group) and having 1 to 2000 carbon atoms, and X is-OSO ₃X¹、-COOX¹or-SO₃X¹(X¹Is H, a metal atom, NR¹ ₄Imidazolium with or without substituent, pyridine with or without substituentOnium, or phosphonium with or without substituents; r¹Are H or organic radicals, which may be identical or different. ) A surfactant shown below). The number of carbon atoms of R is preferably 500 or less, more preferably 100 or less, further preferably 50 or less, and further more preferably 30 or less.

The hydrocarbon surfactant is more preferably at least 1 selected from the group consisting of surfactants represented by the following formulae:

the following formula (a):

[ solution 23]

(in the formula, R^1aThe alkyl group may be a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms, the hydrogen atom bonded to the carbon atom may be substituted with a hydroxyl group or a 1-valent organic group containing an ester bond, the alkyl group may contain a carbonyl group when the carbon atom number is 2 or more, and the alkyl group may contain a 1-valent or 2-valent heterocyclic ring when the carbon atom number is 3 or more. R^2aAnd R^3aIndependently a single bond or a 2-valent linking group. R^1a、R^2aAnd R^3aThe total number of carbon atoms of (2) is 6 or more. X^aIs H, a metal atom, NR^4a ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r ^4aAre H or organic radicals, which may be identical or different. R^1a、R^2aAnd R^3aAny 2 of them may be bonded to each other to form a ring. ) A surfactant (a) represented by the following formula (b):

[ solution 24]

(in the formula, R^1bIs a linear or branched alkyl group having 1 or more carbon atoms, which may have a substituent, or may have a substituentWhen the number of carbon atoms of the cyclic alkyl group having 3 or more carbon atoms of the substituent is 3 or more, a heterocyclic ring having 1 or 2 valences may be included or a ring may be formed. R^2bAnd R^4bIndependently is H or a substituent. R^3bIs an alkylene group having 1 to 10 carbon atoms, which may have a substituent. n is an integer of 1 or more. p and q are independently integers of 0 or more. X^bIs H, a metal atom, NR^5b ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r^5bAre H or organic radicals, which may be identical or different. R^1b、R^2b、R^3bAnd R^4bAny 2 of them may be bonded to each other to form a ring. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-or-CO- (excluding-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR⁶Carbonyl group contained in CO-B-. ) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, R^6bH or an alkyl group having 1 to 4 carbon atoms with or without a substituent. is-OSO in the formula ₃X^bOne side of the bond. ) A surfactant (b) represented by the following formula (c):

[ solution 25]

(in the formula, R^1cThe alkyl group may be a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms, the hydrogen atom bonded to the carbon atom may be substituted with a hydroxyl group or a 1-valent organic group containing an ester bond, the alkyl group may contain a carbonyl group when the carbon atom number is 2 or more, and the alkyl group may contain a 1-valent or 2-valent heterocyclic ring when the carbon atom number is 3 or more. R^2cAnd R^3cIndependently a single bond or a 2-valent linking group. R^1c、R^2cAnd R^3cThe total number of carbon atoms of (2) is 5 or more. A. the^cis-COOX^cor-SO₃X^c(X^cIs H, a metal atom, NR^4c ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r^4cAre H or organic radicals, which may be identical or different. ). R^1c、R^2cAnd R^3cAny 2 of them may be bonded to each other to form a ring. ) A surfactant (c) represented by the formula (d):

[ solution 26]

(in the formula, R^1dThe alkyl group may be a linear or branched alkyl group having 1 or more carbon atoms, which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms, which may have a substituent, and when the number of carbon atoms is 3 or more, a heterocyclic ring having 1 or 2 valences may be included, or a ring may be formed. R ^2dAnd R^4dIndependently is H or a substituent. R^3dIs an alkylene group having 1 to 10 carbon atoms, which may have a substituent. n is an integer of 1 or more. p and q are independently integers of 0 or more. A. the^dIs SO₃X^dor-COOX^d(X^dIs H, a metal atom, NR^5d ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r^5dAre H or organic radicals, which may be identical or different. ). R^1d、R^2d、R^3dAnd R^4dAny 2 of them may be bonded to each other to form a ring. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6d-B-*、-NR^6dCO-B-or-CO- (excluding-CO)₂-B-、-OCO-B-、-CONR^6d-B-、-NR^6dCarbonyl group contained in CO-B-. ) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, R^6dH or an alkyl group having 1 to 4 carbon atoms with or without a substituent. Is represented by A in the formula^dOne side of the bond. ) The surfactant (d) shown.

The surfactant (a) will be explained.

In the formula (a), R^1aIs a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms.

When the number of carbon atoms of the alkyl group is 3 or more, a carbonyl group (-C (═ O) -) may be contained between 2 carbon atoms. When the alkyl group has 2 or more carbon atoms, the carbonyl group may be contained at the end of the alkyl group. I.e. CH ₃Acyl groups such as acetyl represented by — C (═ O) -are also included in the above alkyl groups.

When the alkyl group has 3 or more carbon atoms, it may contain a heterocyclic ring having a valence of 1 or 2, or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, and examples thereof include furan rings and the like. R^1aIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, the 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and the 1-valent heterocyclic ring may be located at the terminal of the alkyl group.

In the present specification, the "number of carbon atoms" of the alkyl group includes both the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the heterocycle. E.g. CH₃-C(＝O)-CH₂-the number of carbon atoms of the group represented is 3, CH₃-C(＝O)-C₂H₄-C(＝O)-C₂H₄-the number of carbon atoms of the group represented is 7, CH₃The number of carbon atoms of the group represented by — C (═ O) — is 2.

In the above alkyl group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R ^101a(in the formula, R^101aIs an alkyl group).

In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

In the formula, R^2aAnd R^3aIndependently a single bond or a 2-valent linking group.

R^2aAnd R^3aPreferably a single bond, a linear or branched alkylene group having 1 or more carbon atoms, or a cyclic alkylene group having 3 or more carbon atoms.

Form R^2aAnd R^3aThe above alkylene group of (a) preferably does not contain a carbonyl group.

In the above alkylene group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^102a(in the formula, R^102aIs an alkyl group).

In the alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

R^1a、R^2aAnd R^3aThe total number of carbon atoms of (2) is 6 or more. The total number of carbon atoms is preferably 8 or more, more preferably 9 or more, further preferably 10 or more, preferably 20 or less, more preferably 18 or less, and further preferably 15 or less.

R^1a、R^2aAnd R^3aAny 2 of them may be bonded to each other to form a ring.

In the formula (a), X^aIs H, a metal atom, NR^4a ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R^4aIs H or an organic group. 4R^4aMay be the same or different. As R^4aPreferably H or an organic group having 1 to 10 carbon atoms, more preferably H or a carbon atomA number of 1 to 4. Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li. As X^aPreferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR^4a ₄From the viewpoint of being readily soluble in water, H, Na, K, Li or NH is more preferable₄From the viewpoint of being more soluble in water, Na, K or NH is more preferable₄Particularly preferred is Na or NH₄From the viewpoint of easy removal, NH is most preferable₄。X^aIs NH₄In the case of the surfactant, the surfactant is excellent in solubility in an aqueous medium, and the metal component is less likely to remain in PTFE or in the final product.

As R^1aPreferably, the alkyl group is a linear or branched alkyl group having 1 to 8 carbon atoms and not containing a carbonyl group, a cyclic alkyl group having 3 to 8 carbon atoms and not containing a carbonyl group, a linear or branched alkyl group having 2 to 45 carbon atoms and containing 1 to 10 carbonyl groups, a cyclic alkyl group having 3 to 45 carbon atoms and containing a carbonyl group, or an alkyl group having 3 to 45 carbon atoms and containing a 1-or 2-valent heterocycle.

In addition, as R^1aMore preferably of the formula:

[ solution 27]

(in the formula, n^11aIs an integer of 0 to 10, R^11aIs a linear or branched alkyl group having 1 to 5 carbon atoms or a cyclic alkyl group having 3 to 5 carbon atoms, R^12aIs an alkylene group having 0 to 3 carbon atoms. At n^11aWhen R is an integer of 2 to 10^12aEach may be the same or different. ) The groups shown.

As n^11aThe number of carbon atoms is preferably 0 to 5, more preferably 0 to 3, and still more preferably 1 to 3.

As R^11aThe above alkyl group of (a) preferably does not contain a carbonyl group.

As R^11aIn the above alkyl group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R ^103a(in the formula, R^103aIs an alkyl group).

As R^11aIn the above alkyl group, 75% or less of the hydrogen atoms bonded to the carbon atom may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, or 25% or less may be substituted with a halogen atom, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

R^12aIs an alkylene group having 0 to 3 carbon atoms. The number of carbon atoms is preferably 1 to 3.

As R^12aThe alkylene group in (b) may be linear or branched.

As R^12aThe above alkylene group of (a) preferably does not contain a carbonyl group. As R^12aMore preferably an ethylene group (-C)₂H₄-) or propylene (-C)₃H₆-)。

As R^12aIn the above alkylene group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^104a(in the formula, R^104aIs an alkyl group).

As R^12aIn the above alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, 25% or less may be substituted with halogen atoms, and a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R^2aAnd R^3aPreferably an alkylene group having 1 or more carbon atoms and not containing a carbonyl group, more preferably an alkylene group having 1 to 3 carbon atoms and not containing a carbonyl groupFurther preferably an ethylene group (-C)₂H₄-) or propylene (-C)₃H₆-)。

The surfactant (a) may be exemplified by the following surfactants. In each formula, X^aAs described above.

[ solution 28]

[ solution 29]

[ solution 30]

[ solution 31]

[ solution 32]

[ solution 33]

[ chemical 34]

[ solution 35]

Next, the surfactant (b) will be described.

In the formula (b), R^1bIs a linear or branched alkyl group having 1 or more carbon atoms, which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms, which may have a substituent.

When the number of carbon atoms of the alkyl group is 3 or more, the alkyl group may contain a heterocyclic ring having a valence of 1 or 2, or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, and examples thereof include furan rings and the like. R^1bIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, the 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and the 1-valent heterocyclic ring may be located at the terminal of the alkyl group.

In the present specification, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the heterocyclic ring.

As R^1bThe substituent which the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

As R^1bThe above alkyl group of (a) preferably does not contain a carbonyl group.

In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

The above alkyl group preferably does not have any substituent.

As R^1bThe alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not have a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not have a substituent, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not include a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not include a carbonyl group, and further more preferablyMore preferably a linear or branched alkyl group having 1 to 10 carbon atoms and no substituent, still more preferably a linear or branched alkyl group having 1 to 3 carbon atoms and no substituent, and particularly preferably a methyl group (-CH) ₃) Or ethyl (-C)₂H₅) Most preferred is methyl (-CH)₃)。

In the formula (b), R^2bAnd R^4bIndependently is H or a substituent. Plural R^2bAnd R^4bEach may be the same or different.

As R^2bAnd R^4bThe substituent(s) is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

As R^2bAnd R^4bThe above alkyl group of (a) preferably does not contain a carbonyl group. In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

The above alkyl group preferably does not have any substituent.

As R^2bAnd R^4bThe alkyl group (C1-10) is preferably a linear or branched alkyl group having 1-10 carbon atoms and not containing a carbonyl group, or a cyclic alkyl group having 3-10 carbon atoms and not containing a carbonyl group, more preferably a linear or branched alkyl group having 1-10 carbon atoms and not containing a carbonyl group, still more preferably a linear or branched alkyl group having 1-3 carbon atoms and not containing a substituent, and particularly preferably a methyl group (-CH)₃) Or ethyl (-C) ₂H₅)。

As R^2bAnd R^4bPreferably, the alkyl group is independently H or a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent, and still more preferably H or a methyl group (-CH)₃) Or ethyl (-C)₂H₅) H is particularly preferred.

In the formula (b), R^3bIs an alkylene group having 1 to 10 carbon atoms, which may have a substituent. R^3bWhen a plurality of the compounds exist, they may be the same or different.

The alkylene group preferably does not contain a carbonyl group.

In the alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The above alkylene group preferably does not have any substituent.

The alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not have a substituent, or a cyclic alkylene group having 3 to 10 carbon atoms which may or may not have a substituent, preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not contain a carbonyl group, or a cyclic alkylene group having 3 to 10 carbon atoms which may or may not contain a carbonyl group, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not have a substituent, and still more preferably a methylene group (-CH) ₂-) ethylene (-C), ethylene (-C)₂H₄-) isopropylidene (-CH (CH)₃)CH₂-) or propylene (-C)₃H₆-)。

R^1b、R^2b、R^3bAnd R^4bAny 2 of these may be bonded to each other to form a ring, but preferably form no ring.

In the formula (b), n is an integer of 1 or more. The number n is preferably an integer of 1 to 40, more preferably an integer of 1 to 30, still more preferably an integer of 5 to 25, particularly preferably 5 to 9, 11 to 25.

In the formula (b), p and q are independently integers of 0 or more. P is preferably an integer of 0 to 10, more preferably 0 or 1. Q is preferably an integer of 0 to 10, more preferably an integer of 0 to 5.

The total of n, p and q is preferably an integer of 5 or more. The total of n, p and q is more preferably an integer of 8 or more. The total of n, p and q is preferably an integer of 60 or less, more preferably an integer of 50 or less, and still more preferably an integer of 40 or less.

In the formula (b), X^bIs H, a metal atom, NR^5b ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R^5bIs H or an organic group. 4R^5bMay be the same or different. As R^5bPreferably, H or an organic group having 1 to 10 carbon atoms, and more preferably H or an organic group having 1 to 4 carbon atoms. Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li. X ^bMay be a metal atom or NR^5b ₄(R^5bAs described above).

As X^bPreferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR^5b ₄From the viewpoint of being readily soluble in water, H, Na, K, Li or NH is more preferable₄From the viewpoint of being more soluble in water, Na, K or NH is more preferable₄Particularly preferred is Na or NH₄From the viewpoint of easy removal, NH is most preferable₄。X^bIs NH₄In the case of the surfactant, the surfactant is excellent in solubility in an aqueous medium, and the metal component is less likely to remain in PTFE or in the final product.

In the formula (b), L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-or-CO- (excluding-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR⁶Carbonyl group contained in CO-B-. ) B is a single bond or an alkylene group having 1 to 10 carbon atoms with or without a substituent, R^6bH or an alkyl group having 1 to 4 carbon atoms with or without a substituent. The number of carbon atoms of the alkylene group is more preferably 1 to 5. In addition, the above R⁶More preferably H or methyl. is-OSO in the formula₃X^bOne side of the bond.

L is preferably a single bond.

As the surfactant (b), preferred is the following formula:

[ solution 36]

(in the formula, R^1b、R^2bL, n and X^bAs described above. ) The compounds shown.

The above-mentioned surfactant (b) is in¹The integral value of all peak intensities observed in a region with a chemical shift of 2.0 to 5.0ppm in an H-NMR spectrum is preferably 10% or more.

The above-mentioned surfactant (b) is in¹The integral value of all peak intensities observed in the region of chemical shift 2.0 to 5.0ppm in the H-NMR spectrum is preferably within the above range. In this case, the surfactant preferably has a ketone structure in the molecule.

In the surfactant (b), the integrated value is more preferably 15 or more, preferably 95 or less, more preferably 80 or less, and still more preferably 70 or less.

The integrated value was measured in a heavy water solvent at room temperature. The heavy water was set to 4.79 ppm.

Examples of the surfactant (b) include

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂OSO₃Na、

(CH₃)₃CC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

(CH₃)₂CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

(CH₂)₅CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OCH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)NHCH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂NHC(O)CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OCH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OC(O)CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃H、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Li、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃K、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃NH₄、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH(CH₃)₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

(CH₃)₃CC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

(CH₃)₂CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

(CH₂)₅CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OCH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)NHCH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂NHC(O)CH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OCH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OC(O)CH₂CH₂OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OSO₃Na、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃H、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Li、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃K、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃NH₄、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OSO₃Na and the like.

The surfactant (c) will be explained.

In the formula (c), R^1cIs a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms.

When the number of carbon atoms of the alkyl group is 3 or more, a carbonyl group (-C (═ O) -) may be contained between 2 carbon atoms. When the number of carbon atoms of the alkyl group is 2 or more, the carbonyl group may be contained at the end of the alkyl group. I.e. CH₃Acyl groups such as acetyl represented by — C (═ O) -are also included in the above alkyl groups.

When the number of carbon atoms of the alkyl group is 3 or more, the alkyl group may contain a heterocyclic ring having a valence of 1 or 2, or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, and examples thereof include furan rings and the like. R ^1cIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, the 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and the 1-valent heterocyclic ring may be located at the terminal of the alkyl group.

In the present specification, the "number of carbon atoms" of the alkyl group includes both the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the heterocycle. E.g. CH₃-C(＝O)-CH₂-the number of carbon atoms of the group represented is 3, CH₃-C(＝O)-C₂H₄-C(＝O)-C₂H₄-a group shownHas 7, CH carbon atoms₃The number of carbon atoms of the group represented by — C (═ O) — is 2.

In the above alkyl group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^101c(in the formula, R^101cIs an alkyl group).

In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

In the formula (c), R ^2cAnd R^3cIndependently a single bond or a 2-valent linking group.

R^2cAnd R^3cPreferably a single bond, a linear or branched alkylene group having 1 or more carbon atoms, or a cyclic alkylene group having 3 or more carbon atoms.

Form R^2cAnd R^3cThe above alkylene group of (a) preferably does not contain a carbonyl group.

In the above alkylene group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^102c(in the formula, R^102cIs an alkyl group).

In the alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

R^1c、R^2cAnd R^3cThe total number of carbon atoms of (2) is 5 or more. The total number of carbon atoms is preferably 7 or more, more preferably 7 or moreIs 9 or more, preferably 20 or less, more preferably 18 or less, and further preferably 15 or less.

R^1c、R^2cAnd R^3cAny 2 of them may be bonded to each other to form a ring.

In the formula (c), A^cis-COOX^cor-SO₃X^c(X^cIs H, a metal atom, NR^4c ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r^4cAre H or organic radicals, which may be identical or different. ). As R^4cPreferably, H or an organic group having 1 to 10 carbon atoms, and more preferably H or an organic group having 1 to 4 carbon atoms. Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li.

As X^cPreferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR^4c ₄From the viewpoint of being readily soluble in water, H, Na, K, Li or NH is more preferable₄From the viewpoint of being more soluble in water, Na, K or NH is more preferable₄Particularly preferred is Na or NH₄From the viewpoint of easy removal, NH is most preferable₄。X^cIs NH₄In the case of the surfactant, the surfactant is excellent in solubility in an aqueous medium, and the metal component is less likely to remain in PTFE or in the final product.

As R^1cPreferably, the alkyl group is a linear or branched alkyl group having 1 to 8 carbon atoms and not containing a carbonyl group, a cyclic alkyl group having 3 to 8 carbon atoms and not containing a carbonyl group, a linear or branched alkyl group having 2 to 45 carbon atoms and containing 1 to 10 carbonyl groups, a cyclic alkyl group having 3 to 45 carbon atoms and containing a carbonyl group, or an alkyl group having 3 to 45 carbon atoms and containing a heterocyclic ring having 1 or 2 valences.

In addition, as R^1cMore preferably of the formula:

[ solution 37]

(in the formula, n^11cIs an integer of 0 to 10, R^11cIs a linear or branched alkyl group having 1 to 5 carbon atoms or a cyclic alkyl group having 3 to 5 carbon atoms, R^12cIs an alkylene group having 0 to 3 carbon atoms. n is^11cWhen R is an integer of 2 to 10^12cEach may be the same or different. ) The groups shown.

As n^11cThe number of carbon atoms is preferably 0 to 5, more preferably 0 to 3, and still more preferably 1 to 3.

As R^11cThe above alkyl group of (a) preferably does not contain a carbonyl group.

As R^11cIn the above alkyl group, the hydrogen atom bonded to the carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but is preferably not substituted with any functional group.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^103c(in the formula, R^103cIs an alkyl group).

As R^11cIn the above alkyl group, 75% or less of the hydrogen atoms bonded to the carbon atom may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, or 25% or less may be substituted with a halogen atom, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

R^12cIs an alkylene group having 0 to 3 carbon atoms. The number of carbon atoms is preferably 1 to 3.

As R^12cThe alkylene group in (b) may be linear or branched.

As R^12cThe above alkylene group of (a) preferably does not contain a carbonyl group. As R^12cMore preferably an ethylene group (-C)₂H₄-) or propylene (-C)₃H₆-)。

As R^12cIn the above alkylene group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, a hydroxyl group (-OH) or a 1-valent organic group containing an ester bond, but it is preferableOptionally not substituted by any functional groups.

Examples of the 1-valent organic group containing an ester bond include the following: -O-C (═ O) -R^104c(in the formula, R^104cIs an alkyl group).

As R^12cIn the above alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, 25% or less may be substituted with halogen atoms, and a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R^2cAnd R^3cPreferably, the alkylene group has 1 or more carbon atoms and does not independently contain a carbonyl group, more preferably 1 to 3 carbon atoms and does not contain a carbonyl group, and still more preferably an ethylene group (-C)₂H₄-) or propylene (-C)₃H₆-)。

The surfactant (c) may be the following surfactant. In the formulae A^cAs described above.

[ solution 38]

[ solution 39]

[ solution 40]

[ solution 41]

[ solution 42]

[ solution 43]

[ solution 44]

[ solution 45]

The surfactant (d) will be explained.

In the formula (d), R^1dIs a linear or branched alkyl group having 1 or more carbon atoms, which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms, which may have a substituent.

When the number of carbon atoms of the alkyl group is 3 or more, the alkyl group may contain a heterocyclic ring having a valence of 1 or 2, or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, and examples thereof include furan rings and the like. R^1dIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, the 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and the 1-valent heterocyclic ring may be located at the terminal of the alkyl group.

In the present specification, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the heterocyclic ring.

As R^1dThe substituent which the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

As R^1dThe above alkyl group of (a) preferably does not contain a carbonyl group.

In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

The above alkyl group preferably does not have any substituent.

As R^1dThe alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not have a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not have a substituent, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not include a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms, which may or may not include a carbonyl group, further preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may or may not have a substituent, further more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, which may or may not have a substituent, and particularly preferably a methyl group (-CH)₃) Or ethyl (-C)₂H₅) Most preferred is methyl (-CH)₃)。

In the formula (d), R^2dAnd R^4dIndependently is H or a substituent. Plural R^2dAnd R^4dEach may be the same or different.

As R^2dAnd R^4dThe substituent(s) is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

As R^2dAnd R^4dThe above alkyl group of (a) preferably does not contain a carbonyl group. In the above alkyl groups, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

The above alkyl group preferably does not have any substituent.

As R^2dAnd R^4dThe alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which does not contain a carbonyl group, or does not contain a carbonyl groupThe alkyl group is preferably a cyclic alkyl group having 3 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, still more preferably a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent, and particularly preferably a methyl group (-CH)₃) Or ethyl (-C)₂H₅)。

As R^2dAnd R^4dPreferably independently H or a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent, and still more preferably H or a methyl group (-CH)₃) Or ethyl (-C)₂H₅) H is particularly preferred.

In the formula (d), R^3dIs an alkylene group having 1 to 10 carbon atoms, which may have a substituent. R ^3dWhen a plurality of the compounds exist, they may be the same or different.

The alkylene group preferably does not contain a carbonyl group.

In the alkylene group, 75% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, or 25% or less may be substituted with halogen atoms, and a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The above alkylene group preferably does not have any substituent.

The alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not have a substituent, or a cyclic alkylene group having 3 to 10 carbon atoms which may or may not have a substituent, preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not contain a carbonyl group, or a cyclic alkylene group having 3 to 10 carbon atoms which may or may not contain a carbonyl group, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may or may not have a substituent, and still more preferably a methylene group (-CH)₂-) ethylene (-C), ethylene (-C)₂H₄-) isopropylidene (-CH (CH)₃)CH₂-) or propylene (-C)₃H₆-)。

R^1d、R^2d、R^3dAnd R^4dAny 2 of (1) may beCombine with each other to form a ring.

In the formula (d), n is an integer of 1 or more. The number n is preferably an integer of 1 to 40, more preferably an integer of 1 to 30, and still more preferably an integer of 5 to 25.

In the formula (d), p and q are independently integers of 0 or more. P is preferably an integer of 0 to 10, more preferably 0 or 1. Q is preferably an integer of 0 to 10, more preferably an integer of 0 to 5.

The total of n, p and q is preferably an integer of 6 or more. The total of n, p and q is more preferably an integer of 8 or more. The total of n, p and q is preferably an integer of 60 or less, more preferably an integer of 50 or less, and still more preferably an integer of 40 or less.

In the formula (d), A^dis-SO₃X^dor-COOX^d(X^dIs H, a metal atom, NR^5d ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent; r^5dAre H or organic radicals, which may be identical or different. ). As R^5dPreferably, H or an organic group having 1 to 10 carbon atoms, and more preferably H or an organic group having 1 to 4 carbon atoms. Examples of the metal atom include a metal atom having a valence of 1 and a metal atom having a valence of 2, and examples thereof include an alkali metal (group 1), an alkaline earth metal (group 2), and the like, and preferably include Na, K, and Li. X^dMay be a metal atom or NR^5d ₄(R^5dAs described above).

As X^dPreferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR^5d ₄From the viewpoint of being readily soluble in water, H, Na, K, Li or NH is more preferable ₄From the viewpoint of being more soluble in water, Na, K or NH is more preferable₄Particularly preferred is Na or NH₄From the viewpoint of easy removal, NH is most preferable₄。X^dIs NH₄In the case of the surfactant, the surfactant is excellent in solubility in an aqueous medium, and the metal component is less likely to remain in PTFE or in the final product.

In the formula (d), L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6d-B-*、-NR^6dCO-B-or-CO- (excluding-CO)₂-B-、-OCO-B-、-CONR^6d-B-、-NR^6dCarbonyl group contained in CO-B-. ) B is a single bond or an alkylene group having 1 to 10 carbon atoms with or without a substituent, R^6dH or an alkyl group having 1 to 4 carbon atoms with or without a substituent. The number of carbon atoms of the alkylene group is more preferably 1 to 5. In addition, the above R^6dMore preferably H or methyl. Is represented by A in the formula^dOne side of the bond.

L is preferably a single bond.

The above surfactant is in¹The integral value of all peak intensities observed in a region with a chemical shift of 2.0 to 5.0ppm in an H-NMR spectrum is preferably 10 or more.

The above surfactant is in¹The integral value of all peak intensities observed in the region of chemical shift 2.0 to 5.0ppm in the H-NMR spectrum is preferably within the above range. In this case, the surfactant preferably has a ketone structure in the molecule.

In the surfactant, the integrated value is more preferably 15 or more, preferably 95 or less, more preferably 80 or less, and further preferably 70 or less.

The integrated value was measured in a heavy water solvent at room temperature. The heavy water was set to 4.79 ppm.

Examples of the surfactant (d) include

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COOK、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

(CH₃)₃CC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

(CH₃)₂CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

(CH₂)₅CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂CH₂COONa、

CH₃CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂CH₂COONa、

CH₃CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂CH₂COONa、

CH₃CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂CH₂COONa、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂CH₂COONa、

CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OCH₂CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)NHCH₂COOK、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂NHC(O)CH₂COOK、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OCH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OC(O)CH₂COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)COOH、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)COOLi、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)COONH₄、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)COONa、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(CH₃)₂COOK、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

(CH₃)₃CC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

(CH₃)₂CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

(CH₂)₅CHC(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂SO₃Na、

CH₃C(O)CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OCH₂CH₂CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)NHCH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂NHC(O)CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(O)OCH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂OC(O)CH₂SO₃Na、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃H、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃K、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃Li、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂SO₃NH₄、

CH₃C(O)CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂C(CH₃)₂SO₃Na

And the like.

In the polymerization, 2 or more kinds of the hydrocarbon-based surfactants may be used simultaneously.

The hydrocarbon-based surfactant in the polymerization is preferably at least 1 selected from the group consisting of the compound (α), the surfactant (1-0) represented by the general formula (1-0), the surfactant (a) represented by the formula (a), the surfactant (b) represented by the formula (b), the surfactant (c) represented by the formula (c), and the surfactant (d) represented by the formula (d).

The hydrocarbon surfactant may be a surfactant obtained by subjecting at least 1 surfactant selected from the group consisting of the compound (α), the surfactant (1-0) represented by the general formula (1-0), the surfactant (a) represented by the formula (a), the surfactant (b) represented by the formula (b), the surfactant (c) represented by the formula (c), and the surfactant (d) represented by the formula (d) to radical treatment or oxidation treatment. The radical treatment may be a treatment for generating radicals in the surfactant, and may be, for example, the following treatment: adding deionized water and hydrocarbon surfactant into a reactor, sealing the reactor, replacing the inside of the system with nitrogen, heating and pressurizing the reactor, adding a polymerization initiator, stirring for a certain time, depressurizing the reactor until the atmospheric pressure is reached, and cooling. The oxidation treatment is a treatment in which an oxidizing agent is added to the surfactant. Examples of the oxidizing agent include oxygen, ozone, hydrogen peroxide, manganese (IV) oxide, potassium permanganate, potassium dichromate, nitric acid, and sulfur dioxide.

Further, the hydrocarbon surfactant is preferably a carboxylic acid type hydrocarbon surfactant. The carboxylic acid type hydrocarbon surfactant is not limited as long as it has a group in which a carboxyl group (-COOH) or a hydrogen atom of the carboxyl group is substituted with an inorganic cation (for example, a metal atom, ammonium, or the like), and, for example, a hydrocarbon surfactant having a group in which a carboxyl group or a hydrogen atom of the carboxyl group is substituted with an inorganic cation in the above-mentioned hydrocarbon surfactant can be used.

The carboxylic acid type hydrocarbon surfactant is preferably at least 1 selected from the group consisting of the compound (α), the surfactant (1-0) represented by the general formula (1-0), a surfactant having a group in which a carboxyl group (-COOH) or a hydrogen atom of the carboxyl group is substituted with an inorganic cation, the surfactant (c) represented by the formula (c), and the surfactant (d) represented by the formula (d).

By the above polymerization, an aqueous dispersion containing a fluoropolymer (aqueous fluoropolymer dispersion) can be obtained. The fluoropolymer is usually present in a concentration of 8 to 50% by mass of the aqueous dispersion obtained by the polymerization. In the aqueous fluoropolymer dispersion, the concentration of the fluoropolymer preferably has a lower limit of 10% by mass, a more preferred lower limit of 15% by mass, a more preferred upper limit of 40% by mass, and a more preferred upper limit of 35% by mass.

The purified aqueous fluoropolymer dispersion obtained by the production method of the present invention has a reduced amount of the fluorine-containing compound represented by the general formula (1) or (2).

The aqueous dispersion obtained by the production method of the present invention may be concentrated or subjected to dispersion stabilization treatment to prepare a dispersion, or may be subjected to coagulation or flocculation, recovered and dried to obtain a solid such as a powder.

The aqueous fluoropolymer dispersion of the present invention can be produced by the production method of the present invention.

The present invention also provides an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the aqueous fluoropolymer dispersion comprises a compound represented by the following general formula (1), and the total content of the compound represented by the following general formula (1) is 1000ppb or less relative to the fluoropolymer.

General formula (1): (H- (CF)₂)_m-COO)_pM¹

(wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄(R⁵May be the same or different, and is H or an organic substance having 1 to 10 carbon atomsA group), an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. p is 1 or 2. )

The total content is the sum of the contents of all fluorine-containing compounds contained in the general formula (1).

In the aqueous fluoropolymer dispersion of the present invention, the total content of the compounds represented by the general formula (1) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb.

The present invention also provides an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the aqueous fluoropolymer dispersion comprises at least one of a compound represented by the following general formula (4) and a compound represented by the following general formula (4 '), wherein the content of the compound represented by the general formula (4) is 1000ppb or less relative to PTFE, and the content of the compound represented by the general formula (4') is 1000ppb or less relative to PTFE. The content of the compound represented by the general formula (4) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (4) is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb. The content of the compound represented by the general formula (4') is 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (4') is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

General formula (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The present invention also provides an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the aqueous fluoropolymer dispersion comprises at least one of a compound represented by the following general formula (5) and a compound represented by the following general formula (5 '), wherein the content of the compound represented by the general formula (5) is 1000ppb or less relative to PTFE, and the content of the compound represented by the general formula (5') is 1000ppb or less relative to PTFE. The content of the compound represented by the general formula (5) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (5) is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb. The content of the compound represented by the general formula (5') may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (5') is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

General formula (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The present invention also provides an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the aqueous fluoropolymer dispersion comprises at least one of a compound represented by the following general formula (6) and a compound represented by the following general formula (6 '), wherein the content of the compound represented by the general formula (6) is 1000ppb or less relative to PTFE, and the content of the compound represented by the general formula (6') is 1000ppb or less relative to PTFE. The content of the compound represented by the general formula (6) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (6) is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb. The content of the compound represented by the general formula (6') may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit of the content of the compound represented by the general formula (6') is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb.

General formula (6): (H- (CF)₂)₁₇-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

General formula (6'): (H- (CF)₂)₁₈-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention preferably contains substantially no compound represented by the general formula (3). The fact that the compound represented by the general formula (3) is not substantially contained means that, for example, the content of the compound represented by the general formula (3) is 150ppb or less with respect to PTFE. The content of the compound represented by the general formula (3) may be 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb.

General formula (3): (H- (CF)₂)₈-SO₃)_qM²

(in the formula, M²Is H, a metal atom, NR ⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. q is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (4) with respect to PTFE. The content of the compound represented by the general formula (4) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (4') with respect to PTFE. The content of the compound represented by the general formula (4') may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb. General formula (4'): (H- (CF) ₂)₈-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (5) with respect to PTFE. The content of the compound represented by the general formula (5) may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (5') with respect to PTFE. The content of the compound represented by the general formula (5') may be 500ppb or less, 400ppb or less, 300ppb or less, 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb. General formula (5'): (H- (CF) ₂)₁₄-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (6) with respect to PTFE. The content of the compound represented by the general formula (6) may be 500ppb or less, 400ppb or less, 300ppb or less, more preferably 250ppb or less, particularly preferably 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb.

General formula (6): (H- (CF)₂)₁₇-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The aqueous fluoropolymer dispersion of the present invention may contain 1000ppb or less of a compound represented by the following general formula (6') with respect to PTFE. The content of the compound represented by the general formula (6') may be 500ppb or less, 400ppb or less, 300ppb or less, more preferably 250ppb or less, 200ppb or less, 150ppb or less, 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less with respect to PTFE. The lower limit is not particularly limited, and may be 0.1ppb or 1 ppb.

General formula (6'): (H- (CF)₂)₁₈-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

In the aqueous fluoropolymer dispersion of the present invention, the content of a compound having n of 4 in the compounds represented by the following general formula (2) may be 150ppb or less relative to PTFE, the content of a compound having n of 5 may be 150ppb or less relative to PTFE, the content of a compound having n of 6 may be 150ppb or less relative to PTFE, the content of a compound having n of 7 may be 150ppb or less relative to PTFE, the content of a compound having n of 8 may be 150ppb or less relative to PTFE, the content of a compound having n of 9 may be 150ppb or less relative to PTFE, the content of a compound having n of 10 may be 150ppb or less relative to PTFE, the content of a compound having n of 11 may be 150ppb or less relative to PTFE, the content of a compound having n of 12 may be 150ppb or less relative to PTFE, the content of a compound having n of 13 may be 150ppb or less relative to PTFE, the content of a compound having n of 14 may be 150ppb or less relative to PTFE, the content of the compound in which n is 15 may be 150ppb or less with respect to PTFE, the content of the compound in which n is 16 may be 150ppb or less with respect to PTFE, the content of the compound in which n is 17 may be 150ppb or less with respect to PTFE, the content of the compound in which n is 18 may be 150ppb or less with respect to PTFE, the content of the compound in which n is 19 may be 150ppb or less with respect to PTFE, and the content of the compound in which n is 20 may be 150ppb or less with respect to PTFE.

General formula (2): (H- (CF)₂)_n-SO₃)_qM²

(wherein n is 4 to 20. M)²Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. q is 1 or 2. )

The content of the compound having n of 4 to 20 may be 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less, respectively. The lower limit is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb. In the aqueous fluoropolymer dispersion of the present invention, the content of any of the compounds represented by the general formula (2) may be 0 ppb.

In the aqueous fluoropolymer dispersion of the present invention, the content of the compound having m 3 in the compounds represented by the following general formula (1) may be 150ppb or less relative to PTFE, the content of the compound having m 4 may be 150ppb or less relative to PTFE, the content of the compound having m 5 may be 150ppb or less relative to PTFE, the content of the compound having m 6 may be 150ppb or less relative to PTFE, the content of the compound having m 7 may be 150ppb or less relative to PTFE, the content of the compound having m 8 may be 150ppb or less relative to PTFE, the content of the compound having m 9 may be 150ppb or less relative to PTFE, the content of the compound having m 10 may be 150ppb or less relative to PTFE, the content of the compound having m 11 may be 150ppb or less relative to PTFE, the content of the compound having m 12 may be 150ppb or less relative to PTFE, the content of the compound having m 13 may be 150ppb or less relative to PTFE, the content of the compound in which m is 14 may be 150ppb or less with respect to PTFE, the content of the compound in which m is 15 may be 150ppb or less with respect to PTFE, the content of the compound in which m is 16 may be 150ppb or less with respect to PTFE, the content of the compound in which m is 17 may be 150ppb or less with respect to PTFE, the content of the compound in which m is 18 may be 150ppb or less with respect to PTFE, and the content of the compound in which m is 19 may be 150ppb or less with respect to PTFE.

General formula (1): (H- (CF)₂)_m-COO)_pM¹

(wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄(R⁵The same or different, H or an organic group having 1 to 10 carbon atoms), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. p is 1 or 2. )

The content of the compound having m of 3 to 19 may be 100ppb or less, 25ppb or less, 15ppb or less, or 10ppb or less, respectively. The lower limit is not particularly limited, and may be 0ppb, 0.1ppb, or 1 ppb.

In the above general formula (1), (2), (3), (4 '), (5 '), (6) or (6 '), 4R⁵May be the same or different. As R⁵Preferably, H or an organic group having 1 to 10 carbon atoms, and more preferably H or an organic group having 1 to 4 carbon atoms.

In the aqueous fluoropolymer dispersion of the present invention, the content of the compound represented by the general formula (1), (2), (3), (4 '), (5 '), (6) or (6 ') is a value measured by liquid chromatography mass spectrometry as described in the examples below.

In the aqueous fluoropolymer dispersion of the present invention, the fluoropolymer is preferably present in a concentration of 10 to 90% by mass of the aqueous fluoropolymer dispersion. The lower limit of the concentration of the fluoropolymer is preferably 20% by mass, more preferably 30% by mass, still more preferably 40% by mass, still more preferably 50% by mass, and particularly preferably 55% by mass. The upper limit is preferably 80% by mass, and the more preferable upper limit is 70% by mass.

The aqueous fluoropolymer dispersion of the present invention may contain a nonionic surfactant. The content of the nonionic surfactant is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 2% by mass or more, relative to the fluoropolymer. Further, it is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 7% by mass or less.

The nonionic surfactant used in the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, which is performed before the step B, can be used.

The aqueous fluoropolymer dispersion of the present invention preferably contains substantially no fluorosurfactant. In the present specification, "substantially free of a fluorinated surfactant" means that the amount of the fluorinated surfactant is 10ppm or less relative to the fluoropolymer. The content of the fluorosurfactant is preferably 1ppm or less, more preferably 100ppb or less, further more preferably 10ppb or less, further more preferably 1ppb or less, and particularly preferably the fluorosurfactant measured by liquid chromatography-mass spectrometry (LC/MS) is not more than the detection limit.

The amount of the above-mentioned fluorosurfactant can be determined by a known method. For example, quantification can be performed by LC/MS/MS analysis. First, the obtained aqueous fluoropolymer dispersion was extracted in an organic solvent such as methanol, and molecular weight information was extracted from the LC/MS spectrum of the extract solution to confirm the identity with the structural formula of the surfactant candidate.

Then, for the identified surfactants, 5 levels or more of aqueous solutions were prepared, and LC/MS analysis was performed for each concentration to prepare a calibration curve with respect to the area of the region.

The obtained aqueous fluoropolymer dispersion was subjected to soxhlet extraction with methanol, and the extract was subjected to LC/MS analysis, whereby quantitative measurement was possible.

That is, the fluorosurfactant content can be quantified, for example, by LC/MS/MS analysis. First, methanol was added to an aqueous dispersion to extract the extract, and the obtained extract was analyzed by LC/MS/MS. In order to further improve the extraction efficiency, treatment such as soxhlet extraction or ultrasonic treatment may be performed. Molecular weight information was extracted from the obtained LC/MS/MS spectrum, and the identity with the structural formula of the fluorosurfactant as a candidate was confirmed. Then, aqueous solutions containing 5 or more levels of the identified fluorosurfactant were prepared, LC/MS analysis was performed on the aqueous solutions containing the respective levels, and a standard curve was drawn by plotting the relationship between the content and the area of the region relative to the content. Then, the area of the LC/MS chromatogram of the fluorosurfactant in the extract can be converted to the fluorosurfactant content using a standard curve.

The content of the fluorosurfactant in the aqueous dispersion can be determined by the method described later, and the limit of the determination can be increased by adding an extraction solvent to the aqueous dispersion and further concentrating the extracted liquid. Further, the quantitative limit can be increased by increasing the amount of the aqueous dispersion liquid at the time of extraction or by decreasing the amount of the extraction solvent.

The fluorinated surfactant is the same as the surfactant exemplified in the method for producing the aqueous fluoropolymer dispersion. For example, the surfactant may contain a fluorine atom having a total carbon number of a portion other than the anionic group of 20 or less, may contain a fluorine atom having a molecular weight of 800 or less in the anionic portion, or may contain a fluorine atom having a LogPOW of 3.5 or less.

Examples of the anionic fluorosurfactant include those represented by the general formula (N)⁰) Specific examples of the compound represented by the formula (N) include¹) A compound represented by the general formula (N)²) A compound represented by the general formula (N)³) A compound represented by the general formula (N)⁴) A compound represented by the formula (N)⁵) Is shown by The compound of (1). More specifically, there may be mentioned perfluorocarboxylic acid (I) represented by general formula (I), ω -H perfluorocarboxylic acid (II) represented by general formula (II), perfluoropolyether carboxylic acid (III) represented by general formula (III), perfluoroalkylalkylene carboxylic acid (IV) represented by general formula (IV), perfluoroalkoxy fluorocarboxylic acid (V) represented by general formula (V), perfluoroalkylsulfonic acid (VI) represented by general formula (VI), omega-H perfluorosulfonic acid (VII) represented by general formula (VII), perfluoroalkylalkylalkylene sulfonic acid (VIII) represented by general formula (VIII), alkylalkylalkylene carboxylic acid (IX) represented by general formula (IX), fluorocarboxylic acid (X) represented by general formula (X), alkoxyfluorosulfonic acid (XI) represented by general formula (XI), compound (XII) represented by general formula (XIII), and compound (XIII) represented by general formula (XIII).

Examples

The present invention will be described with reference to the following examples, but the present invention is not limited to these examples.

In the examples, the measurement of each physical property was performed by the following method.

Content of solid component

The following values were used: the ratio of the mass of the remaining components after heating to the mass (1g) of the aqueous dispersion of PTFE was expressed as a percentage.

Average primary particle diameter

The measurement was performed by a dynamic light scattering method. An aqueous fluoropolymer dispersion was prepared by adjusting the fluoropolymer solid content to about 1.0% by mass, and the total of 70 measurements were carried out at 25 ℃ using ELSZ-1000S (available from Otsuka Denshi Co., Ltd.). The refractive index of the solvent (water) was 1.3328, and the viscosity of the solvent (water) was 0.8878 mPas.

Content of specific compound containing fluorine

Hereinafter, a method of measuring the content of the compounds represented by the following general formulae (1) and (2) as specific compounds containing fluorine will be described.

General formula (1): (H- (CF)₂)_m-COO)_pM¹(wherein M is 3 to 19, M¹Is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. p is 1 or 2. )

General formula (2): (H- (CF)₂)_n-SO₃)_qM²(wherein n is 4 to 20. M)²Is H, a metal atom, NR⁵ ₄An imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. q is 1 or 2. )

The content of the specific compound containing fluorine was measured using liquid chromatography mass spectrometry under the following conditions.

The solid content of the aqueous dispersion was measured, and the aqueous dispersion was weighed out in an amount of 0.5g of solid content of PTFE into a 100mL screw tube. Then, water and methanol were added so that the water contained in the aqueous dispersion was combined to make the extraction solvent 40g (43.14mL) of water/methanol 50/50 vol%. Then, the mixture was shaken until it was condensed. Removing solid components, centrifuging the liquid phase at 4000rpm for 1 hour, and extracting a supernatant containing the compound represented by the general formula (1) and the compound represented by the general formula (2) as an extract.

[ method for measuring the content of Compound represented by general formula (1) ]

Measurement of content of Compound represented by general formula (1) contained in extract

The content of the compound represented by the general formula (1) contained in the extract liquid is determined by converting the content into perfluorooctanoic acid.

Standard curve of perfluorooctanoic acid

5 levels of 1ng/mL to 100ng/mL standard solutions of perfluorooctanoic acid in methanol of known concentration were prepared and measured using a liquid chromatography mass spectrometer (Waters, LC-MS ACQUITYUPLC/TQD). From the respective sample concentrations and the integrated values of the peaks, a and b were obtained by the following relational expression (1) using first order approximation.

A＝a×X+b (1)

A: peak area of perfluorooctanoic acid

X: concentration of Perfluorooctanoic acid (ng/mL)

Measurement apparatus constitution and LC/MS/MS measurement conditions

[ Table 1]

MRM measurement parameters

[ Table 2]

The content of the compound represented by the general formula (1) having 4 to 20 carbon atoms in the extract liquid

A compound represented by the general formula (1) having 4 to 20 carbon atoms is measured using a liquid chromatography mass spectrometer. The peak area of the compound represented by the general formula (1) for each carbon number was determined for the extracted liquid phase by the MRM method.

MRM measurement parameters

[ Table 3]

TABLE 3

The content of the compound represented by the general formula (1) having carbon atoms (m +1) in the extract liquid was calculated by using the following formula (3). A and b in the formula (3) are obtained from the formula (1).

XCm＝((ACm-b)/a)×((50×m+45)/413) (3)

XCm: the content (ng/mL) of the compound represented by the general formula (1) having carbon number (m +1) in the extract solution

ACm: the peak area of the compound represented by the general formula (1) having carbon number (m +1) in the extraction solution

The limit of quantitation in this assay was 1 ng/mL.

The content of the compound represented by the general formula (1) having carbon atoms (m +1) contained in the aqueous dispersion

The content of the compound represented by the general formula (1) having carbon atoms (m +1) contained in the aqueous dispersion is determined by the following formula (5).

ZCm＝XCm×86.3 (5)

ZCm: the content (ppb, relative to PTFE) of the compound represented by the general formula (1) having carbon number (m +1) contained in the aqueous dispersion

[ method for measuring the content of Compound represented by the general formula (2) ]

Measurement of content of Compound represented by the general formula (2) contained in the extract

The content of the compound represented by the general formula (2) contained in the extract liquid is determined by conversion to perfluorooctanesulfonic acid.

Standard curve of perfluorooctanesulfonic acid

5 levels of 1ng/mL to 100ng/mL standard solutions of perfluorooctanesulfonic acid in methanol of known concentration were prepared and measured using a liquid chromatography mass spectrometer (Waters, LC-MS ACQUITYUPLC/TQD). From the respective sample concentrations and the integrated values of the peaks, a and b were obtained by the following relational expression (1) using first order approximation.

A＝a×X+b (1)

A: peak area of Perfluorooctanesulfonic acid

X: concentration of Perfluorooctanesulfonic acid (ng/mL)

Measurement apparatus constitution and LC/MS/MS measurement conditions

[ Table 4]

MRM measurement parameters

[ Table 5]

The content of the compound represented by the general formula (2) having 4 to 20 carbon atoms in the extract liquid

A compound represented by the general formula (2) having 4 to 20 carbon atoms is measured using a liquid chromatography mass spectrometer. The peak area of the compound represented by the general formula (2) for each carbon number was determined for the extracted liquid phase by the MRM method.

MRM measurement parameters

[ Table 6]

TABLE 6

The content of the compound represented by the general formula (2) having n carbon atoms in the extract liquid was calculated by using the following formula (3). A and b in the formula (3) are obtained from the formula (1).

XSn＝((ASn-b)/a)×((50×n+81)/499) (3)

XSn: the content (ng/mL) of the compound represented by the general formula (2) having n carbon atoms in the extract solution

ASn: the peak area of the compound represented by the general formula (2) having n carbon atoms in the extraction solution

The limit of quantitation in this assay was 1 ng/mL.

The content of the compound represented by the general formula (2) having n carbon atoms in the aqueous dispersion

The content of the compound represented by the general formula (2) having n carbon atoms contained in the aqueous dispersion is determined by the following formula (5).

ZSn＝XSn×86.3 (5)

ZSn: the content (ppb, relative to PTFE) of the compound represented by the general formula (2) having n carbon atoms contained in the aqueous dispersion

In the synthesis example, polymerization was carried out using sodium 10-oxoundecylsulfate (hereinafter referred to as surfactant A).

Synthesis example 1

588.6g of deionized water and 70.0g of a surfactant A were placed in a 1L glass reactor equipped with a stirrer, the reactor was sealed, and the inside of the system was replaced with nitrogen gas to remove oxygen. The reactor was warmed to 90 ℃ and pressurized to 0.4MPaG with nitrogen. 41.4g of Ammonium Persulfate (APS) was charged and stirred for 3 hours. Stopping stirring, depressurizing the reactor until the pressure reaches the atmospheric pressure, and cooling to obtain a surfactant aqueous solution B.

Synthesis example 2

3600g of deionized and degassed water, 180g of paraffin wax and 0.540g of a surfactant A were charged into a SUS reactor having an internal volume of 6L and equipped with a stirrer, the reactor was sealed, and the inside of the system was replaced with nitrogen gas to remove oxygen. The reactor was warmed to 90 ℃ and charged with TFE to give a reactor pressure of 2.70 MPaG. As a polymerization initiator, 0.031g of Ammonium Persulfate (APS) and 1.488g of disuccinic acid peroxide (DSP) were charged. TFE was fed so that the reaction pressure was constant at 2.70 MpaG. At the same time as the start of the feeding of TFE, the continuous feeding of the surfactant aqueous solution B was started. When 1650g of TFE was added, the stirring was stopped, and the pressure was removed until the reactor reached atmospheric pressure. 139g of the surfactant aqueous solution B was charged until the reaction was completed. The contents were taken out of the reactor, cooled, and the paraffin wax was separated to obtain an aqueous PTFE dispersion C.

The solid content of the obtained PTFE aqueous dispersion C was 31.7 mass%, and the average primary particle diameter was 357 nm.

Synthesis example 3 preparation example of aqueous PTFE Dispersion containing nonionic surfactant

To the aqueous PTFE dispersion C obtained in synthesis example 2 was added a nonionic surfactant (T-Det a138, manufactured by hacross Chemicals, cloud point 44 ℃) in an amount corresponding to 10.0 mass% relative to PTFE, and the mixture was gently dispersed with a resin rod to obtain an aqueous PTFE dispersion D containing a nonionic surfactant.

Synthesis example 4

In a beaker containing 100g to 200mL of the aqueous PTFE dispersion D obtained in Synthesis example 3, 18g of an anion exchange resin (Amberjet IRA4002OH, manufactured by DuPont) was added, and the mixture was stirred with a stirrer for 30 minutes with such strength that no flocculation occurred. After standing for 3 hours, the anion exchange resin was removed with a mesh to obtain an aqueous PTFE dispersion E.

Example 1

An anion exchange resin (PFA694E, manufactured by Purolite) was further added to the purified PTFE aqueous dispersion E obtained in Synthesis example 4 in the same proportion (18g) as in Synthesis example 4, and the same operation was carried out to obtain a PTFE aqueous dispersion F.

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to PTFE in an amount of 15 mass% per PTFE in the aqueous PTFE dispersion F, and the mixture was allowed to stand at 48 ℃ for 4 hours to separate into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion G).

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) and water were added to the concentrated phase (aqueous PTFE dispersion G) to adjust the content of PTFE to 25% by mass and the content of the nonionic surfactant to 15% by mass/PTFE, and the mixture was allowed to stand at 44 ℃ for 4 hours, whereby the mixture was separated into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially did not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous dispersion of PTFE H).

Example 2

After adding a nonionic surfactant (T-Det a138, manufactured by Hacros Chemicals) and water to the concentrated phase (PTFE aqueous dispersion H) obtained in example 1 to adjust the PTFE content to 25 mass% and the nonionic surfactant content to 15 mass%/PTFE, the mixture was allowed to stand at 44 ℃ for 4 hours, and as a result, the mixture was separated into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion I).

Example 3

An anion exchange resin (PFA694E, manufactured by Purolite) was further added to the aqueous PTFE dispersion F of example 1 in the same proportion (18g) as in Synthesis example 4, and the same operation was carried out to obtain an aqueous PTFE dispersion J.

A non-ionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to PTFE in an amount of 15 mass% per PTFE in the aqueous PTFE dispersion J, and the mixture was allowed to stand at 48 ℃ for 4 hours to separate into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous dispersion of PTFE K).

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) and water were added to the above-mentioned concentrated phase (aqueous PTFE dispersion K) to adjust the content of PTFE to 25% by mass and the content of the nonionic surfactant to 15% by mass/PTFE, and then the mixture was allowed to stand at 44 ℃ for 4 hours, whereby the mixture was separated into 2 phases of a supernatant phase and a concentrated phase which substantially contained no PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion L).

Example 4

After adding a nonionic surfactant (T-Det a138, manufactured by Hacros Chemicals) and water to the concentrated phase (aqueous PTFE dispersion L) obtained in example 3 to adjust the content of PTFE to 25 mass% and the content of the nonionic surfactant to 15 mass%/PTFE, the mixture was allowed to stand at 44 ℃ for 4 hours, and as a result, the mixture was separated into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion M).

Example 5

To the aqueous PTFE dispersion F of example 1 was further added a synthetic adsorbent (Amberlite FPX66, manufactured by dupont, pore size:pore volume: 1.9cm³Specific surface area,/g: 914m²And/g) was carried out in the same manner as above to obtain an aqueous PTFE dispersion N.

A non-ionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to PTFE in an amount of 15 mass% per PTFE in an aqueous PTFE dispersion N, and the mixture was allowed to stand at 48 ℃ for 4 hours to separate into 2 phases, a supernatant phase and a concentrated phase, which substantially contained no PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous dispersion O of PTFE).

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to PTFE in an amount of 15 mass% per PTFE in the aqueous PTFE dispersion O, and the mixture was allowed to stand at 44 ℃ for 4 hours to separate into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous dispersion of PTFE P).

Example 6

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to the aqueous PTFE dispersion P obtained in example 5 in an amount of 15 mass% per PTFE, and the mixture was allowed to stand at 44 ℃ for 4 hours, whereby the mixture was separated into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially contained no PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous dispersion of PTFE R).

Comparative example 1

An anion exchange resin (Amberjet IRA4002OH, manufactured by DuPont) was further added to the aqueous PTFE dispersion E obtained in Synthesis example 4 in the same ratio (18g) as in Synthesis example 4, and the same operation was carried out to obtain an aqueous PTFE dispersion S.

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) was added to PTFE in an amount of 15 mass% per PTFE in the aqueous PTFE dispersion S, and the mixture was allowed to stand at 48 ℃ for 4 hours to separate into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion T).

Comparative example 2

A nonionic surfactant (T-Det A138, manufactured by Hacross Chemicals) and water were added to the aqueous PTFE dispersion T of comparative example 1 to adjust the PTFE content to 25% by mass and the nonionic surfactant content to 15% by mass/PTFE, and the mixture was allowed to stand at 48 ℃ for 4 hours to separate into 2 phases, i.e., a supernatant phase and a concentrated phase, which substantially do not contain PTFE. The supernatant phase was removed to obtain a concentrated phase (aqueous PTFE dispersion U).

The limit of quantitation in the case of aqueous dispersions is 86 ppb. In the present invention, "E" in the tables represents an index. For example, a statement of "2.8E + 03" means 2.8X 10³。