阅读说明：本技术 含氟聚合物的制造方法 (Method for producing fluorine-containing polymer ) 是由 吉田裕俊 加藤丈人 市川贤治 藤本阳平 难波义典 伊藤剑吾 东昌弘 米田聪 山内昭佳 于 2019-03-07 设计创作，主要内容包括：本发明的目的在于提供一种能够减少杂质含量的含氟聚合物的制造方法。本发明涉及一种含氟聚合物的制造方法,其特征在于,包括下述聚合工序：在表面活性剂的存在下,在水性介质中进行含氟单体的聚合,由此得到含氟聚合物,上述表面活性剂为羧酸型的含烃表面活性剂。(The purpose of the present invention is to provide a method for producing a fluoropolymer, wherein the content of impurities can be reduced. The present invention relates to a method for producing a fluorine-containing polymer, which is characterized by comprising the following polymerization steps: the fluorine-containing polymer is obtained by polymerizing a fluorine-containing monomer in an aqueous medium in the presence of a surfactant, which is a carboxylic acid type hydrocarbon-containing surfactant.)

1. A method for producing a fluorine-containing polymer, comprising the following polymerization steps: polymerizing a fluorine-containing monomer in an aqueous medium in the presence of a surfactant to obtain a fluorine-containing polymer,

the surfactant is a carboxylic acid type hydrocarbon-containing surfactant.

2. The manufacturing method according to claim 1, further comprising the steps of: the fluoropolymer obtained in the polymerization step is dried at 155 ℃ or higher.

3. The production process according to claim 1 or 2, wherein the polymerization of the fluorine-containing monomer is carried out in an aqueous medium substantially not containing the nonionic surfactant in the polymerization step.

4. The production process according to any one of claims 1 to 3, wherein the amount of the carboxylic acid type hydrocarbon-containing surfactant at the initial stage of polymerization in the polymerization step is more than 50ppm based on the aqueous medium.

5. The production method according to any one of claims 1 to 4, wherein a polymerization initiator is added to the aqueous medium in the polymerization step.

6. The production method according to claim 5, wherein the polymerization initiator is a redox initiator.

7. The production process according to claim 5, wherein the polymerization initiator is a radical polymerization initiator.

8. The production process according to any one of claims 1 to 7, wherein the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group, and wherein the carbonyl group is not a carboxyl group.

9. The production process according to any one of claims 1 to 8, wherein the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the concentration of the fluoropolymer particles formed in the aqueous medium in the polymerization step is 0.36% by mass or less.

10. The production process according to any one of claims 1 to 9, wherein in the polymerization step, a carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started.

11. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0 MPa.

12. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the polymerization initiator is a redox initiator.

13. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the polymerization initiator is a redox initiator,

the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the start of polymerization or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36 wt% or less.

14. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the polymerization initiator is a redox initiator,

the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group, except for a carbonyl group in the carboxyl group.

15. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the start of polymerization or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less.

16. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization initiator is a redox initiator,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less, a carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium.

17. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization initiator is a redox initiator,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization starts.

18. The production process according to any one of claims 1 to 5, wherein,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group, except for a carbonyl group in the carboxyl group.

19. The production process according to any one of claims 1 to 11,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization temperature is 30-100 ℃,

the polymerization pressure is 0.5MPa to 5.0MPa,

Adding a carboxylic acid type hydrocarbon-containing surfactant to an aqueous medium before the start of polymerization or when the concentration of fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less,

the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group, except for a carbonyl group in the carboxyl group.

20. The production method according to any one of claims 5, 6 and 8 to 19,

in the polymerization step, the polymerization reaction mixture is subjected to a polymerization reaction,

the polymerization pressure is more than 1.5MPa,

the polymerization initiator is a redox initiator.

21. The production process according to any one of claims 1 to 20, wherein the carboxylic acid type hydrocarbon-containing surfactant is a compound represented by the following formula (A),

R-COO-M (A)

wherein R is an alkyl group, alkenyl group, alkylene group or alkenylene group having 2 to 29 carbon atoms, which may or may not 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, H or an organic group having 1 to 10 carbon atoms.

22. The production process according to claim 21, wherein in the formula (A), R is an alkyl group or an alkenyl group, which may or may not contain an ether bond.

23. The production method according to any one of claims 1 to 22, wherein an aqueous fluoropolymer dispersion is obtained in the polymerization step, the aqueous fluoropolymer dispersion containing substantially no compound represented by the following general formula (3) and containing more than 20ppm of a compound represented by the following general formula (4) relative to the fluoropolymer,

General formula (3): (H- (CF)₂)₈-SO₃)_qM²

In the formula, M²Is 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; q is 1 or 2; r¹¹The same or different, H or an organic group with 1-10 carbon atoms;

general formula (4): (H- (CF)₂)₇-COO)_pM¹

In the formula, 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.

Technical Field

The present invention relates to a method for producing a fluoropolymer.

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-containing surfactant instead of a fluorinated anionic surfactant (see, for example, patent documents 1 to 3).

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a novel method for producing a fluoropolymer.

Means for solving the problems

The present invention relates to a method for producing a fluorine-containing polymer, which is characterized by comprising the following polymerization steps: the fluorine-containing polymer is obtained by polymerizing a fluorine-containing monomer in an aqueous medium in the presence of a surfactant, which is a carboxylic acid type hydrocarbon-containing surfactant.

The production method of the present invention preferably further comprises the steps of: the fluoropolymer obtained in the polymerization step is dried at 155 ℃ or higher.

The polymerization step is preferably a step of polymerizing the fluorine-containing monomer in an aqueous medium substantially not containing the nonionic surfactant. In the polymerization step, the amount of the carboxylic acid type hydrocarbon-containing surfactant at the initial stage of polymerization is preferably more than 50ppm based on the aqueous medium.

In the above polymerization step, a polymerization initiator is preferably added to the aqueous medium.

The polymerization initiator is preferably a redox initiator. The polymerization initiator is preferably a radical polymerization initiator.

The above carboxylic acid type hydrocarbon-containing surfactant preferably does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

In the polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less.

In the polymerization step, the carboxylic acid type hydrocarbon-containing surfactant is preferably added to the aqueous medium before the polymerization is started.

In the polymerization step, the polymerization temperature is preferably from 30 ℃ to 100 ℃ and the polymerization pressure is preferably from 0.5MPa to 5.0 MPa.

In the polymerization step, the polymerization temperature is preferably 30 to 100 ℃, the polymerization pressure is preferably 0.5 to 5.0MPa, and the polymerization initiator is preferably a redox initiator.

In the above polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, the polymerization initiator is a redox initiator, and the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36 wt% or less.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, the polymerization initiator is a redox initiator, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0 MPa.

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the polymerization initiator is a redox initiator, the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, and the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less.

In the polymerization step, it is preferable that the polymerization initiator is a redox initiator, the polymerization temperature is 30 to 100 ℃ and the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃ and the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0MPa, and before the start of the polymerization or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in the carboxyl group).

In the polymerization step, the polymerization pressure is preferably 1.5MPa or more, and the polymerization initiator is preferably a redox initiator.

The carboxylic acid type hydrocarbon-containing surfactant is preferably a compound represented by the following formula (a).

R-COO-M(A)

(wherein R is an alkyl group, alkenyl group, alkylene group or alkenylene group having 2 to 29 carbon atoms, which may or may not 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, H or an organic group having 1 to 10 carbon atoms. )

In the above formula (A), R is preferably an alkyl group or an alkenyl group, which may or may not contain an ether bond.

In the polymerization step, it is preferable that the aqueous fluoropolymer dispersion is obtained and contains substantially no compound represented by the following general formula (3) and more than 20ppm of a compound represented by the following general formula (4) relative to the fluoropolymer.

General formula (3): (H- (CF)₂)₈-SO₃)_qM²

(in the formula, M²Is H, a metal atom, NR¹¹ ₄Imidazolium with or without substituent, pyridinium with or without substituentOr phosphonium with or without substituents. q is 1 or 2. R¹¹The same or different, H or an organic group having 1 to 10 carbon atoms. )

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, M ¹Is 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. )

ADVANTAGEOUS EFFECTS OF INVENTION

The production method of the present invention can produce a novel fluoropolymer.

Detailed Description

Before the present invention is explained in detail, some terms used in the present specification are defined or explained.

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

In the present specification, melt processability means that a polymer can be melted and processed by 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 means an amorphous fluoropolymer. The "amorphous state" means a case where the size of a melting peak (. DELTA.H) appearing in differential scanning calorimetry [ DSC ] (temperature rise temperature 10 ℃ C./minute) or differential thermal analysis [ DTA ] (temperature rise rate 10 ℃ C./minute) of the fluoropolymer is 4.5J/g or less. Fluororubbers exhibit elastomeric properties by crosslinking. The elastomer properties refer to the following properties: the polymer is capable of stretching and retaining its original length without the application of the force required to stretch the polymer.

In the present specification, the partially fluorinated rubber is a fluoropolymer containing a fluoromonomer unit and a perfluoromonomer unit in an amount of less than 90 mol% based on the total polymerized units, and has a glass transition temperature of 20 ℃ or less and a melting peak (. DELTA.H) size of 4.5J/g or less.

In the present specification, the perfluororubber is a fluoropolymer having a perfluoromonomer unit content of 90 mol% or more relative to the total polymerized units, has a glass transition temperature of 20 ℃ or less, has a melting peak (Δ H) size of 4.5J/g or less, and further has a fluorine atom concentration of 71 mass% or more. In the present specification, the concentration of fluorine atoms contained in the fluoropolymer is determined by calculating the concentration (mass%) of fluorine atoms contained in the fluoropolymer from the type and content of each monomer constituting the fluoropolymer.

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

The monomer providing the crosslinking site is a monomer (vulcanization 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 polytetrafluoroethylene [ PTFE ] is preferably a fluoropolymer having a tetrafluoroethylene content of 99 mol% or more based on the total polymerized units.

In the present specification, both the fluororesin (excluding polytetrafluoroethylene therein) and the fluororubber are preferably a fluoropolymer having a tetrafluoroethylene content of less than 99 mol% relative to the total polymerized units.

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 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 which may have 1 or more substituents,

Cycloalkenyl group which may have 1 or more substituents,

A cycloalkadienyl group which may have 1 or more substituents,

An aryl group which may have 1 or more substituents,

An aralkyl group which may have 1 or more substituents,

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

A heteroaryl group which may have 1 or more substituents,

A cyano group,

Formyl, methyl,

R^aO-、

R^aCO-、

R^aSO₂-、

R^aCOO-、

R^aNRaCO-、

R^aCONRa-、

R^aOCO-、

R^aOSO₂-, and,

R^aNRbSO₂-

(in the formulae, R^aIndependently is

An alkyl group which may 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 which may have 1 or more substituents,

Cycloalkenyl group which may have 1 or more substituents,

A cycloalkadienyl group which may have 1 or more substituents,

An aryl group which may have 1 or more substituents,

An aralkyl group which may have 1 or more substituents,

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

A heteroaryl group which may have 1 or more substituents,

R^bindependently H or an alkyl group which may have 1 or more substituents).

The organic group is preferably an alkyl group which may have 1 or more substituents.

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

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

In the present specification, the expression "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, etc.).

The present invention will be described in detail below.

The production method of the present invention is characterized by comprising the following polymerization steps: the fluorine-containing polymer is obtained by polymerizing a fluorine-containing monomer in an aqueous medium in the presence of a surfactant, which is a carboxylic acid type hydrocarbon-containing surfactant.

In the conventional polymerization of a fluorine-containing polymer, a sulfonic acid type hydrocarbon-containing surfactant is used, and a carboxylic acid type hydrocarbon-containing surfactant is not used to polymerize a fluorine-containing monomer.

The present inventors have conducted extensive studies and as a result, have found that a fluoropolymer can be obtained in a high yield with high emulsion stability and little adhesion when a carboxylic acid type hydrocarbon-containing surfactant is used, and have completed the present invention.

The above carboxylic acid type hydrocarbon-containing surfactant is generally an anionic surfactant having a hydrophilic portion of a carboxylic acid salt and a hydrophobic portion as a long-chain hydrocarbon portion such as an alkyl group.

Examples of the carboxylic acid type hydrocarbon-containing surfactant include the following formulae:

R¹⁰-COOM

(in the formula, R¹⁰Is a 1-valent organic group containing 1 or more carbon atoms. M is H, a metal atom, NR¹¹ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R¹¹Is H or an organic group, which may be the same or different). As R¹¹Preferably H or C_1-10More preferably H or C_1-4An organic group of (2).

From the aspect of surface-active ability, R¹⁰The number of carbon atoms of (b) is preferably 2 or more, more preferably 3 or more. In addition, from the aspect of water solubilityStarting from 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。

The carboxylic acid type hydrocarbon-containing surfactant may also include R¹²-COOM (wherein R ¹²Is 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 may or may not 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 wound. M is the same as above).

Specifically, CH may be mentioned₃-(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 hydrocarbon-containing surfactant preferably does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

In addition, the surfactant used in the polymerization is preferably only a hydrocarbon-containing surfactant containing no carbonyl group.

As the hydrocarbon-containing surfactant containing no carbonyl group, for example, a compound of the following formula (a) is preferably exemplified.

R-COO-M (A)

(wherein R is an alkyl group, alkenyl group, alkylene group or alkenylene group having 6 to 17 carbon atoms, which may or may not contain an ether bond; M is H, a metal atom, NR¹¹ ₄Imidazolium with or without substituents, pyridinium with or without substituents, or A substituted phosphonium. R¹¹The same or different, H or an organic group having 1 to 10 carbon atoms. )

In the above formula (A), R is preferably an alkyl group or an alkenyl group (which may or may not contain an ether bond). The alkyl group or alkenyl group in the above-mentioned R may be linear or branched. The number of carbon atoms in R is not limited, and is, for example, 2 to 29.

When the alkyl group is linear, the number of carbon atoms of 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 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 hydrocarbon-containing surfactant include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecyl 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, eicosatrienoic acid, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, crotonic acid, myristic acid, palmitoleic acid, cis-6-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-, Eicosatrienoic acid, dihomo-gamma-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenalic acid, bosseopentaenoic acid, eicosapentaenoic acid, docosapentaenoic acid (clinanococcic acid), tetracosapentaenoic acid, docosahexaenoic acid, herring acid, and salts thereof.

Particularly, at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecyl acid, palmitic acid, and salts thereof is preferable.

Examples of the salt include a metal atom having a carboxyl group and a hydrogen atom of the formula M, NR¹¹ ₄The salt is not particularly limited, but may be an imidazolium salt having a substituent, a pyridinium salt having a substituent, or a phosphonium salt having a substituent.

Examples of the carboxylic acid type hydrocarbon-containing surfactant in the present invention include those selected from the following formula (a):

[ solution 1]

(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, and 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, and may contain a carbonyl group in the case of having 2 or more carbon atoms, or may contain a 1-valent or 2-valent heterocyclic ring in the case of having 3 or more carbon atoms, or may be wound into a ring. 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 5 or more. A. the^ais-COOX^a(X^aIs H, a metal atom, NR^4a ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R ^4aH or an organic group, which may be the same 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 formula (a) and the following formula (b):

[ solution 2]

(in the formula, 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, and when the number of carbon atoms is 3 or more, it may contain a heterocyclic ring having 1 or 2 valences, or may be wound into a ring. R^2bAnd R^4bIndependently is H or a substituent. R^3bIs an alkylene group having 1 to 10 carbon atoms, which may or may not have a substituent. n is an integer of 1 or more. p and q are independently integers of 0 or more. A. the^bis-COOX^b(X^bIs H, a metal atom, NR^5b ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R^5bH or an organic group, which may be the same 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- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl 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, and R ^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. Is represented by A in the formula^bBonded side) of the surfactant (b).

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 is 3 or more, the alkyl group may contain a carbonyl group (-C (═ O) -) 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. CH₃Acyl groups such as an acetyl group represented by — C (═ O) -, are also included in the above alkyl groups.

In addition, when the number of carbon atoms of the alkyl group is 3 or moreThe compound may contain a heterocyclic ring having a valence of 1 or 2, or may be wound into 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. At R^1aIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, a 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and a 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 also includes the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the heterocyclic ring. E.g. CH ₃-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, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but non-halogenated alkyl groups containing no halogen atom such as a fluorine atom or a chlorine atom are preferable.

In the formula (a), R^2aAnd R^3aIndependently a single bond or a 2-valent linking group.

R^2aAnd R^3aIndependently, 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 is preferable.

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).

Of the above alkylene 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, and 25% or less may be substituted with halogen atoms, but 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 5 or more. The total number of carbon atoms is preferably 7 or more, more preferably 9 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), A^ais-COOX^a(X^aIs H, a metal atom, NR^4a ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R^4aAre H or an organic group, which may be the same or different. ). As R^4aPreferably, 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 alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable.

As X^aPreferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR^4a ₄H, Na, K, Li or NH is more preferable because it is easily soluble in water₄Na, K or NH is further preferable because it is more soluble in water₄Particularly preferred is Na or NH₄NH is most preferable because of its easy removal₄. If X^aIs NH₄The surfactant is excellent in solubility in an aqueous medium, and the metal component hardly remains in the fluoropolymer or in the final product。

As R^1aPreferably, the alkyl group is a linear or branched alkyl group having 1 to 8 carbon atoms, which does not include a carbonyl group, a cyclic alkyl group having 3 to 8 carbon atoms, which does not include a carbonyl group, a linear or branched alkyl group having 2 to 45 carbon atoms, which includes 1 to 10 carbonyl groups, a cyclic alkyl group having 3 to 45 carbon atoms, which includes a carbonyl group, or an alkyl group having 3 to 45 carbon atoms, which includes a 1-or 2-valent heterocycle.

In addition, as R^1aMore preferably of the formula:

[ solution 3]

(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. n is^11aWhen R is an integer of 2 to 10, R^12aEach may be the same or different).

As n^11aPreferably an integer of 0 to 5, more preferably an integer of 0 to 3, and further preferably an integer of 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 groups, 75% or less of the hydrogen atoms bonded to the carbon atoms may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, and 25% or less may be substituted with a halogen atom, but 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, and 25% or less may be substituted with halogen atoms, but a non-halogenated alkylene group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

As R^2aAnd R^3aIndependently, an alkylene group having 1 or more carbon atoms which does not contain a carbonyl group is preferable, an alkylene group having 1 to 3 carbon atoms which does not contain a carbonyl group is more preferable, and an ethylene group (-C)₂H₄-) or propylene (-C)₃H₆-)。

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 is 3 or more, the alkyl group may contain a heterocyclic ring having a valence of 1 or 2, or may be entangled to 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. At R^1bIn the above formula, a 2-valent heterocyclic ring may be inserted between 2 carbon atoms, a 2-valent heterocyclic ring may be located at the terminal and bonded to — C (═ O) -, and a 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 also 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, or 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, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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, 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 not include a carbonyl group, further preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may not have a substituent, further more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, which 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 (b), R^2bAnd R^4bIndependently is H or a substituent. More than 2R^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 atomsThe group or the cyclic alkyl group or hydroxyl group having 3 to 10 carbon atoms, 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, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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 (C) is preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group or a cyclic alkyl group having 3 to 10 carbon atoms and not containing a carbonyl group, 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^2bAnd R^4bIndependently, H or a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group is preferable, H or a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent group is more preferable, and H or a methyl group (-CH) is further more preferable₃) 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 or may not have a substituent. R^3bWhen there are 2 or more, they may be the same or different.

The alkylene group preferably does not contain a carbonyl group.

Of the above alkylene 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, and 25% or less may be substituted with halogen atoms, but a non-halogenated alkylene 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 have a substituent or may not have a substituent or a cyclic alkylene group having 3 to 10 carbon atoms which may have a substituent or not, preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may not include a carbonyl group or a cyclic alkylene group having 3 to 10 carbon atoms which may not include a carbonyl group, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which 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 them may be bonded to each other to form a 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, and still more preferably an integer of 5 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 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 (b), A^bis-COOX^b(X^bIs H, a metal atom, NR^5b ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R^5bIs H or an organic group, which may 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 alkali metals (group 1), alkaline earth metals (group 2), and the like, and Na, K, and Li are preferable. 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 ₄H, Na, K, Li or NH is more preferable because it is easily soluble in water₄Na, K or NH is further preferable because it is more soluble in water₄Particularly preferred is Na or NH₄NH is most preferable because of its easy removal₄. If X^bIs NH₄The surfactant is excellent in solubility in an aqueous medium, and the metal component hardly remains in the fluoropolymer 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- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. The alkylene group preferably has 1 to 5 carbon atoms. In addition, the above R^6bMore preferably H or methyl. Is represented by A in the formula^bOne side of the bond.

L is preferably a single bond.

For the above surfactants, in¹In the H-NMR spectrum, the integral value of all peak intensities observed in a region with a chemical shift of 2.0 to 5.0ppm is preferably 10% or more.

For the above surfactants, in¹In the H-NMR spectrum, the integral value of all peak intensities observed in the region of chemical shift 2.0 to 5.0ppm 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 still more preferably 70 or less.

The integral value was measured at room temperature using a heavy water solvent. The heavy water was set to 4.79 ppm.

The surfactant (a) is a novel compound, and can be produced, for example, by the production method exemplified below.

The surfactant (a) can be produced by a production method including the following steps.

A step (11a) for converting the formula:

[ solution 4]

(in the formula, R^3aAs described above, E^aIs a leaving group) with lithium, and a compound of formula (10 a): r^201a ₃Si-Cl (in the formula, R)^201aIndependently an alkyl or aryl) to yield a chlorosilane compound of the formula:

[ solution 5]

(in the formula, R^3a、R^201aAnd E^aThe compound (11a) represented by the above);

a step (12a) of reacting the compound (11a) with a compound of the formula:

[ solution 6]

(in the formula, R^1aAs mentioned above, R^21aIs a single bond or a 2-valent linking group) to give an olefin of the formula:

[ solution 7]

(in the formula, R^1a、R^21a、R^3aAnd E^aThe compound (12a) represented by the above);

a step (13a) of removing the leaving group possessed by the compound (12a) to obtain a compound represented by the formula:

[ solution 8]

(in the formula, R^1a、R^21aAnd R^3aThe compound (13a) represented by the above); and

Step (14a) of oxidizing compound (13a) to obtain a compound represented by the formula:

[ solution 9]

(in the formula, R^1a、R^21aAnd R^3aAs described above) of the compound (14 a).

R^1aWhen the furan ring is contained, the furan ring can be opened by an acid to convert into a dicarbonyl derivative, for example. Examples of the acid include acetic acid, hydrochloric acid, and p-tolylsulfone. The same applies to other manufacturing methods described later.

E^aRepresents a leaving group. Examples of the leaving group include t-butyldimethylsilyl (TBS), Triethylsilyl (TES), Triisopropylsilyl (TIPS), t-butyldiphenylsilyl (TBDPS), and benzyl (Bn). The same applies to other manufacturing methods described later.

As R^21aA single bond or a linear or branched alkylene group having 1 or more carbon atoms is preferable.

Examples of the chlorosilane compound include

[ solution 10]

All reactions in step (11a) can be carried out in a solvent. As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

In the step (12a), the reaction ratio of the compound (11a) and the olefin may be 1 to 2 moles of the olefin per 1 mole of the compound (11a) in view of improvement of yield and reduction of waste.

The reaction in the step (12a) may be carried out in a solvent in the presence of a thiazolium salt and a base.

Examples of the thiazolium salt include 3-ethyl-5- (2-hydroxyethyl) -4-methylthiazolium bromide, 3-benzyl-5- (2-hydroxyethyl) -4-methylthiazolium chloride, and the like.

Examples of the base include 1, 8-diazabicyclo [5.4.0] -7-undecene and triethylamine.

As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

The leaving group elimination reaction in the step (13a) can be carried out by using a fluoride ion or an acid. Examples of the method for releasing the leaving group include: a method using hydrofluoric acid; a method using an amine complex of hydrogen fluoride such as pyridine nHF or triethylamine nHF; using cesium fluoride, potassium fluoride, lithium tetrafluoroborate (LiBF)₄) A method of using an inorganic salt such as ammonium fluoride; organic salts such as tetrabutylammonium fluoride (TBAF).

The leaving group elimination reaction in the step (13a) may be carried out in a polar solvent. As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

The oxidation in the step (14a) may be carried out in a solvent in the presence of sodium chlorite.

As the solvent, alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol and tert-butanol, and water can be used. As the buffer, a disodium hydrogen phosphate solution can be used.

Compound (14a) may also be contacted with a base to convert-COOH to a salt form. Examples of the base include sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia, and an aqueous solution of ammonia is used.

After completion of each step, the solvent may be distilled off, or distillation, purification, or the like may be performed to improve the purity of the obtained compound.

The surfactant (a) can be produced by a production method including the following steps.

A step (21a) for converting the formula:

[ solution 11]

(in the formula, R^3aAs mentioned above, R^22aIs a 1-valent organic radical, E^aIs a leaving group) with a ketone of formula (la):

[ solution 12]

(in the formula, R^1aAs mentioned above, R^23aIs a 1-valent organic group) to yield a carboxylic acid ester of the formula:

[ solution 13]

(in the formula, R^1a、R^3aAnd E^aAs mentioned above, R^24aA single bond or a 2-valent linking group);

a step (22a) of removing the leaving group of the compound (21a) to obtain a compound represented by the formula:

[ solution 14]

(in the formula, R^1a、R^24aAnd R^3aThe compound (22a) represented by the above); and

step (23a) of oxidizing compound (22a) to obtain a compound represented by the formula:

[ solution 15]

(in the formula, R^1a、R^24aAnd R^3aAs described above) or a compound (23 a).

As R^22aThe alkyl group is preferably a linear or branched alkyl group having 1 or more carbon atoms, and more preferably a methyl group.

As R^23aThe alkyl group is preferably a linear or branched alkyl group having 1 or more carbon atoms, and more preferably a methyl group.

As R^24aThe alkylene group is preferably a linear or branched alkylene group having 1 or more carbon atoms, and more preferably a methylene group (-CH)₂-)。

The reaction in the step (21a) may be carried out in a solvent in the presence of a base.

Examples of the base include sodium amide, sodium hydride, sodium methoxide, sodium ethoxide, and the like.

As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

The leaving group elimination reaction in the step (22a) can be carried out by using a fluoride ion or an acid. Examples of the method for releasing the leaving group include: a method using hydrofluoric acid; a method using an amine complex of hydrogen fluoride such as pyridine nHF or triethylamine nHF; using cesium fluoride, potassium fluoride, lithium tetrafluoroborate (LiBF) ₄) A method of using an inorganic salt such as ammonium fluoride; organic salts such as tetrabutylammonium fluoride (TBAF).

The leaving group elimination reaction in the step (22a) may be carried out in a solvent. As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

The oxidation in the step (23a) may be carried out in a solvent in the presence of sodium chlorite.

As the solvent, alcohol and water can be used. As the buffer, a disodium hydrogen phosphate solution can be used.

Compound (23a) may be contacted with a base to convert-COOH into a salt form. Examples of the base include sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia, and an aqueous solution of ammonia is used.

After completion of each step, the solvent may be distilled off, or distillation, purification, or the like may be performed to improve the purity of the obtained compound.

The surfactant (a) can be produced by a production method including the following steps.

A step (31a) for converting the formula: y is^a-R^3a-CH₂-OE^a

(in the formula, R^3aAs described above, Y^aIs a halogen atom, E^aIs a leaving group) with an alkyl halide of the formula:

[ solution 16]

(in the formula, R^1aAs described above) to give a compound of formula:

[ solution 17]

(in the formula, R^1a、R^3aAnd E^aThe compound (31a) represented by the above);

step (32a) of oxidizing compound (31a) to obtain a compound represented by the formula:

[ solution 18]

(in the formula, R^1a、R^3aAnd E^aThe compound (32a) represented by the above);

a step (33a) of removing the leaving group possessed by the compound (32a) to obtain a compound represented by the formula:

[ solution 19]

(in the formula, R^1aAnd R^3aThe compound (33a) represented by the above); and

step (34a) of oxidizing compound (33a) to obtain a compound represented by the formula:

[ solution 20]

(in the formula, R^1aAnd R^3aAs described above) or a compound (34 a).

In the step (31a), the ratio of the alkyl halide to the lithium acetylide may be 1 to 2 moles of the lithium acetylide with respect to 1 mole of the alkyl halide in view of improving the yield and reducing waste.

The reaction in step (31a) may be carried out in a solvent. The solvent may be hexane.

The oxidation in the step (32a) can be carried out in a nitrile solvent using a complex obtained by reacting (NH)₄)₂Ce(NO₃)₆And trifluoroacetic acid to [ (Cn)^*)Ru^III(CF₃CO₂)₃]·H₂O (in the formula, Cn)^*Representing 1,4, 7-trimethyl-1, 4, 7-triazabicyclononane) and sodium perchlorate.

After the oxidation is completed, the compound (32a) may be neutralized with a base and extracted with an organic solvent such as ether.

The leaving group elimination reaction in the step (33a) can be carried out by using a fluoride ion or an acid. Examples of the method for releasing the leaving group include: a method using hydrofluoric acid; a method using an amine complex of hydrogen fluoride such as pyridine nHF or triethylamine nHF; using cesium fluoride, potassium fluoride, lithium tetrafluoroborate (LiBF)₄) A method of using an inorganic salt such as ammonium fluoride; organic salts such as tetrabutylammonium fluoride (TBAF).

The leaving group elimination reaction in the step (33a) may be carried out in a solvent. As the solvent, an organic solvent can be used, and an aprotic polar solvent, specifically, an ether can be exemplified.

The oxidation in the step (34a) may be carried out in a solvent in the presence of sodium chlorite.

As the solvent, alcohol and water can be used. As the buffer, a disodium hydrogen phosphate solution can be used.

Compound (34a) may be contacted with a base to convert-COOH to a salt form. Examples of the base include sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia, and specifically, an aqueous solution of ammonia can be used.

After completion of each step, the solvent may be distilled off, or distillation, purification, or the like may be performed to improve the purity of the obtained compound.

The surfactant (a) can be produced by a production method including the following steps.

A step (51a) for converting the formula:

[ solution 21]

A divinylketone is disclosed having the formula:

[ solution 22]

The 2-methylfuran shown reacts to give the formula:

[ solution 23]

A compound (51a) shown;

a step (52a) of reacting a compound (51a) with a compound represented by the formula:

[ solution 24]

The furan shown reacts to give the formula:

[ solution 25]

A compound (52a) shown;

a step (53a) of heating the compound (52a) in the presence of an acid, thereby obtaining a compound of the formula:

[ solution 26]

A compound (53a) shown; and

step (54a) of oxidizing compound (53a) to obtain a compound represented by the formula:

[ solution 27]

The compound (54a) shown.

In the step (51a), the reaction ratio of divinyl ketone and 2-methylfuran may be 0.5 to 1 mole of 2-methylfuran per 1 mole of divinyl ketone, in view of improvement in yield and reduction in waste.

The reaction in the step (51a) may be carried out in the presence of an acid. Examples of the acid include acetic acid, hydrochloric acid, and p-toluenesulfonic acid.

The amount of the acid used in the step (51a) may be 0.1 to 2 moles per 1 mole of the divinylketone, in view of improving the yield and reducing the waste.

The reaction in the step (51a) may be carried out in a polar solvent. Examples of the solvent include water and acetonitrile.

In the step (52a), the reaction ratio of the compound (51a) and furan is 1 to 2 moles of furan per 1 mole of the compound (51a) in view of improving the yield and reducing waste.

The reaction in the step (52a) may be carried out in the presence of an acid, and examples of the acid include acetic acid, hydrochloric acid, and p-tolylsulfone.

The amount of the acid used in the step (52a) may be 0.1 to 2 moles per 1 mole of the compound (51a) in view of improvement of yield and reduction of waste.

The reaction in step (52a) may be carried out in a polar solvent. Examples of the solvent include water.

In the step (53a), the compound (52a) is heated in the presence of an acid to open the furan ring.

As the acid, hydrochloric acid or sulfuric acid can be used.

The reaction in the step (53a) may be carried out in a polar solvent. As the solvent, water may be exemplified.

The oxidation in the step (54a) may be carried out in a solvent in the presence of sodium chlorite.

As the solvent, t-butanol and water can be used. As the buffer, a disodium hydrogen phosphate solution can be used.

Compound (54a) may be contacted with a base to convert-COOH to a salt form. Examples of the base include sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia, and specifically, an aqueous solution of ammonia can be used.

After completion of each step, the solvent may be distilled off, or distillation, purification, or the like may be performed to improve the purity of the obtained compound.

The surfactant (a) can be produced by a production method including the following steps.

A step (61a) of converting the formula:

[ solution 28]

(in the formula, R^1aAs mentioned above, R^21aIs a single bond or a 2-valent linking group) with an olefin of the formula:

[ solution 29]

(in the formula, Y^61aIs an alkyl ester group) to give an alkyne of the formula:

[ solution 30]

(in the formula, R^1a、R^21aAnd Y^61aThe compound (61a) represented by the above); and

a step (62a) of reacting the compound (61a) with a base and then with an acid to obtain a compound represented by the formula:

[ solution 31]

(in the formula, R^1aAnd R^21aAs described above) of the compound (62 a).

In the step (61a), the reaction ratio of the olefin to the alkyne can be 0.5 to 2 moles of the olefin per 1 mole of the alkyne in view of improvement of yield and reduction of waste.

The reaction in the step (61a) may be carried out in the presence of a metal catalyst. Examples of the metal include ruthenium.

The amount of the metal catalyst used in the step (61a) may be 0.01 to 0.4 mol based on 1 mol of the olefin, in view of improvement of yield and reduction of waste.

The reaction in step (61a) may be carried out in a polar solvent. Examples of the solvent include water, acetonitrile, dimethylacetamide and dimethylformamide.

In the step (62a), the reaction ratio of the compound (61a) and the base may be 0.6 to 2 moles of the base per 1 mole of the compound (61a) in view of improving the yield and reducing waste.

The amount of the acid used in the step (62a) may be 1.0 to 20.0 moles per 1 mole of the compound (61a) in view of improving the yield and reducing waste.

The reaction in step (62a) may be carried out in a polar solvent. Examples of the solvent include water.

Compound (62a) may be contacted with a base to convert-COOH to a salt form. Examples of the base include sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia, and for example, an aqueous solution of ammonia can be used.

After completion of each step, the solvent may be distilled off, or distillation, purification, or the like may be performed to improve the purity of the obtained compound.

The surfactant (b) is a novel compound, and can be produced, for example, by the following production method.

The surfactant (b) can be produced by a production method including the following steps.

A step (11b) of converting the following formula:

[ solution 32]

(in the formula, R^1b、R^2bAnd n is as defined above) with the formula:

[ solution 33]

(in the formula, R^3bAs described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-, or-CO- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. Means and in formula-S (═ O)₂One side of the bond) shownSultone reaction to give the formula:

[ chemical 34]

(in the formula, R^1b～R^3bN and X^bAs described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-, or-CO- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. is-OSO in the formula₃X^bThe side to which bonding is made) of the compound (11 b).

The reaction in the step (11b) may be carried out in the presence of a base.

Examples of the base include sodium hydride, sodium hydroxide, potassium hydroxide, and triethylamine. The base may be used in an amount of 0.5 to 20 mol based on 1 mol of the compound (10 b).

The reaction in the step (11b) may be carried out in a solvent.

As the solvent, an organic solvent can be used, and aprotic polar solvents, specifically, ethers, aromatic compounds, nitriles, halogenated hydrocarbons, and the like can be used.

The surfactant (b) can be produced by a production method including the following steps.

A step (21b) for adjusting the following formula:

[ solution 35]

(in the formula, R^1b～R^4bN, p and q are as described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-, or-CO- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. is-CH in the formula₂-OH bonded side) to yield the following formula:

[ solution 36]

(in the formula, R^1b～R^4bN, p, q and X^bAs described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-, or-CO- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is ^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. is-CH in the formula₂-COOX^bThe side to which bonding is made) of the compound (21 b).

The oxidation in step (21b) can be carried out by allowing a nitrosating agent to act on compound (20 b).

As the nitrosating agent, sodium nitrite, nitrosylsulfuric acid, isoamylnitrite, and the like can be used.

The nitrosating agent may be used in an amount of 0.5 to 10 mol based on 1 mol of the compound (20 b).

The oxidation in the step (21b) may be carried out in a solvent. As the solvent, trifluoroacetic acid, acetonitrile, or the like can be used.

The compound (10b) and the compound (20b) can be produced by a production method including the following steps.

A step (101b) for converting a compound represented by the formula:

R^11b-CH＝CH-Y^1b-OH

(in the formula, R^11bIs H, carbon with or without substituentsThe alkyl group having 1 or more carbon atoms in a linear or branched state or a cyclic alkyl group having 3 or more carbon atoms with or without a substituent may contain a heterocyclic ring having a valence of 1 or 2 when the number of carbon atoms is 3 or more, or may be wound into a ring. Y is^1bIs- (CR)^2b ₂)_n-or- (CR)^2b ₂)n-(OR^3b)_p-(CR^4b ₂)_q-L-CH₂-(R^2b～R^4bN, p and q are as described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6d-B-*、-NR^6dCO-B-, or-CO- (wherein-CO) ₂-B-、-OCO-B-、-CONR^6d-B-、-NR^6dExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6dIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. is-CH in the formula₂-one side of the bond)) to obtain the following formula:

[ solution 37]

(in the formula, R^11bAnd Y^1bThe compound (101b) represented by the above); and

a step (102b) of oxidizing the compound (101b) to obtain the following formula:

[ solution 38]

(in the formula, R^11bAnd Y^1bAs described above) of the compound (102 b).

As R^11bThe above alkyl group of (a) preferably does not contain a carbonyl group.

As R^11bIn the above alkyl groups, 75% or less of the hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, 50% or less may be substituted with halogen atoms, and 25% or less may be substituted with halogen atoms, but it is preferable thatA non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is selected.

The above alkyl group preferably does not have any substituent.

As R^11bThe alkyl group is preferably H, a linear or branched alkyl group having 1 to 9 carbon atoms with or without a substituent, or a cyclic alkyl group having 3 to 9 carbon atoms with or without a substituent, more preferably H, a linear or branched alkyl group having 1 to 9 carbon atoms which does not include a carbonyl group, or a cyclic alkyl group having 3 to 9 carbon atoms which does not include a carbonyl group, still more preferably H, or a linear or branched alkyl group having 1 to 9 carbon atoms which does not include a substituent, and still more preferably H or a methyl group (-CH) ₃) Or ethyl (-C)₂H₅) Particularly preferred is H or methyl (-CH)₃) Most preferably, H.

The hydroxylation in the step (101b) can be carried out, for example, by the following method: (1b) a method of allowing iron (II) phthalocyanine (fe (pc)) and sodium borohydride to act on the compound (100b) in an oxygen atmosphere; (2b) isopinocampheylborane (IpcBH)₂) A method in which the compound (100b) is allowed to act thereon, and then the obtained intermediate (dialkylboron) is oxidized.

In the method (1b), the amount of the iron (II) phthalocyanine may be a catalyst amount, and may be used in an amount of 0.001 to 1.2 mol based on 1 mol of the compound (100 b).

In the method (1b), sodium borohydride may be used in an amount of 0.5 to 20 mol based on 1 mol of the compound (100 b).

The reaction of the process (1b) may be carried out in a solvent. As the solvent, an organic solvent can be used, and specific examples thereof include ethers, halogenated hydrocarbons, aromatic hydrocarbons, nitriles, nitrogen-containing polar organic compounds, and the like.

In the method (2b), the isobornene may be used in an amount of 1.0 to 10.0 mol based on 1 mol of the compound (100 b).

The reaction of compound (100b) with isobornylborane may be carried out in a solvent. As the solvent, an organic solvent can be used, and specific examples thereof include ethers, halogenated hydrocarbons, aromatic hydrocarbons, and the like.

The reaction temperature of the compound (100b) with isobornene may be-78 to 200 ℃.

The pressure for the reaction of the compound (100b) with isobornene can be 0 to 5.0 MPa.

The reaction time of the compound (100b) with isobornene can be 0.1 to 72 hours.

The oxidation in the method (2b) may be carried out by allowing an oxidizing agent to act on the intermediate. Examples of the oxidizing agent include hydrogen peroxide. The oxidizing agent may be used in an amount of 0.7 to 10 mol based on 1 mol of the intermediate.

The oxidation in the process (2b) may be carried out in a solvent. Examples of the solvent include water, methanol, and ethanol.

In the step (102b), examples of the method for oxidizing the compound (101b) include: (a) using Jones reagent (CrO)₃/H₂SO₄) Method (jones oxidation); (b) methods using dess-martin periodinane (DMP) (dess-martin oxidation); (c) a method using pyridinium chlorochromate (PCC); (d) in NiCl₂A method in which a bleaching agent (about 5 to 6% aqueous solution of NaOCl) is allowed to act on a nickel compound in the presence of the compound; (e) in Al (CH)₃)₃、Al[OCH(CH₃)₂]₃And a method of allowing a hydrogen acceptor such as an aldehyde or a ketone to act thereon in the presence of an aluminum catalyst (Wolff oxidation).

The oxidation in the step (102b) may be carried out in a solvent. As the solvent, water and an organic solvent can be used, and specifically, water, a ketone, an ether, a halogenated hydrocarbon, an aromatic hydrocarbon, a nitrile, and the like can be mentioned.

The compound (10b) and the compound (20b) can be produced by a production method including the following steps.

A step (201b) for converting a compound represented by the formula:

[ solution 39]

(in the formula, R^1bAnd Y^1bAs described above. R^101bIs an organic group) to give the following formula:

[ solution 40]

(in the formula, R^1bAnd Y^1bAs described above) of the compound (201 b).

As R^101bPreferably, the alkyl group has 1 to 20 carbon atoms. 2R^101bMay be the same or different.

The ozonolysis in step (201b) can be carried out by allowing ozone to act on the compound (200b) and then subjecting the compound to a post-treatment with a reducing agent.

Ozone can be produced by silent discharge in oxygen.

Examples of the reducing agent used in the above-mentioned post-treatment include zinc, dimethyl sulfide, thiourea, phosphines, and the like.

The ozonolysis in step (201b) may be carried out in a solvent. As the solvent, water and an organic solvent can be used, and water, an alcohol, a carboxylic acid, an ether, a halogenated hydrocarbon, an aromatic hydrocarbon, and the like can be mentioned.

The compound (10b) and the compound (20b) can be produced by a production method including the following steps.

A step (301b) for converting the following formula:

R^21b-CH＝CH-Y^1b-OH

(in the formula, Y^1bAs described above. R^21bIs H, a linear or branched alkyl group having 1 or more carbon atoms with or without a substituent, or a cyclic alkyl group having 3 or more carbon atoms with or without a substituent, and when the number of carbon atoms is 3 or more, may contain a heterocyclic ring having 1 or 2 valences, or may be wound into a ring), to obtain the following formula:

[ solution 41]

(in the formula, R^21bAnd Y^1bThe compound (301b) shown as above);

a step (302b) of reacting the compound (301b) with R^22b ₂CuLi(R^22bIs a linear or branched alkyl group having 1 or more carbon atoms with or without a substituent, or a cyclic alkyl group having 3 or more carbon atoms with or without a substituent, and when the number of carbon atoms is 3 or more, may contain a heterocyclic ring having 1 or 2 valences, or may be wound into a ring), to obtain the following formula:

[ solution 42]

(in the formula, R^21b、R^22bAnd Y^1bCompound (302b) as described above); and

step (303b) of oxidizing the compound (302b) to obtain the following formula:

[ solution 43]

(in the formula, R^21b、R^22bAnd Y^1bAs described above) of the compound (303 b).

As R^21bThe above alkyl group of (a) preferably does not contain a carbonyl group.

As R^21bIn the above alkyl groups, 75% or less of the hydrogen atoms bonded to the carbon atoms may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, and 25% or less may be substituted with a halogen atom, but a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The above alkyl group preferably does not have any substituent.

As R^21bPreferably, H, a linear or branched alkyl group having 1 to 8 carbon atoms, which may have a substituent, or a carbon atom which may have a substituentA cyclic alkyl group having 3 to 8 atoms, more preferably H, a linear or branched alkyl group having 1 to 8 carbon atoms and not containing a carbonyl group, or a cyclic alkyl group having 3 to 8 carbon atoms and not containing a carbonyl group, still more preferably H, or a linear or branched alkyl group having 1 to 8 carbon atoms and not containing a substituent, and particularly preferably H or a methyl group (-CH)₃) Most preferably, H.

As R^22bThe above alkyl group of (a) preferably does not contain a carbonyl group.

As R^22bIn the above alkyl groups, 75% or less of the hydrogen atoms bonded to the carbon atoms may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, and 25% or less may be substituted with a halogen atom, but a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The above alkyl group preferably does not have any substituent.

As R^22bThe alkyl group is preferably a linear or branched alkyl group having 1 to 9 carbon atoms, which may or may not have a substituent, or a cyclic alkyl group having 3 to 9 carbon atoms, more preferably a linear or branched alkyl group having 1 to 9 carbon atoms, which may or may not include a carbonyl group, or a cyclic alkyl group having 3 to 9 carbon atoms, which may not include a carbonyl group, even more preferably a linear or branched alkyl group having 1 to 9 carbon atoms, which may not have a substituent, and particularly preferably a methyl group (-CH)₃) Or ethyl (-C)₂H₅) Most preferred is methyl (-CH)₃)。

2R^22bMay be the same or different.

R^21bAnd R^22bThe total number of carbon atoms of (A) is preferably 1 to 7, more preferably 1 to 2.

The epoxidation in the step (301b) can be carried out by allowing an epoxidizing agent to act on the compound (300 b).

Examples of the epoxidizing agent include m-chloroperbenzoic acid (m-CPBA), perbenzoic acid, peracids such as hydrogen peroxide and t-butyl hydroperoxide, dimethyldioxirane, methyltrifluoromethyldioxirane, and the like.

The epoxidizing agent may be used in an amount of 0.5 to 10.0 mol based on 1 mol of the compound (300 b).

The epoxidation in the step (301b) may be carried out in a solvent. As the solvent, an organic solvent can be used, and examples thereof include ketones, ethers, halogenated hydrocarbons, aromatic hydrocarbons, nitriles, pyridine, nitrogen-containing polar organic compounds, dimethyl sulfoxide, and the like.

In the step (302b), the lithium dialkylcopper may be used in an amount of 0.5 to 10.0 mol based on 1 mol of the compound (301 b).

The reaction in the step (302b) may be carried out in a solvent. As the solvent, an organic solvent may be used, and examples thereof include ethers, halogenated hydrocarbons, aromatic hydrocarbons, and the like.

In the step (303b), examples of a method for oxidizing the compound (302b) include: (a) using Jones reagent (CrO)₃/H₂SO₄) Method (jones oxidation); (b) methods using dess-martin periodinane (DMP) (dess-martin oxidation); (c) a method using pyridinium chlorochromate (PCC); (d) in NiCl₂A method in which a bleaching agent (about 5 to 6% aqueous solution of NaOCl) is allowed to act on a nickel compound in the presence of the compound; (e) in Al (CH)₃)₃、Al[OCH(CH₃)₂]₃And a method of allowing a hydrogen acceptor such as an aldehyde or a ketone to act thereon in the presence of an aluminum catalyst (Wolff oxidation).

The oxidation in the step (303b) may be carried out in a solvent. As the solvent, water and an organic solvent can be used, and water, ketones, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, nitriles, and the like can be mentioned.

The compound (10b) and the compound (20b) can be produced by a production method including the following steps.

A step (401b) for converting a compound represented by the formula:

R^11b-CH＝CH-Y^1b-OH

(in the formula, R ^11bAnd Y^1bAs described above) to give the following formula:

[ solution 44]

(in the formula, R^11bAnd Y^1bAs described above) of the compound (401 b).

The oxidation in the step (401b) can be carried out by allowing an oxidizing agent to act on the compound (100b) in the presence of water and a palladium compound.

Examples of the oxidizing agent include monovalent or divalent copper salts such as copper chloride, copper acetate, copper cyanide, and copper trifluoromethanesulfonate; iron salts such as ferric chloride, ferric acetate, ferric cyanide, ferric trifluoromethanesulfonate, and hexacyanoferrate; benzoquinones such as 1, 4-benzoquinone, 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone, tetrachloro-1, 2-benzoquinone, and tetrachloro-1, 4-benzoquinone; h₂O₂、MnO₂、KMnO₄、RuO₄Meta-chloroperbenzoic acid, oxygen, etc.

The oxidizing agent may be used in an amount of 0.001 to 10 mol based on 1 mol of the compound (100 b).

The water may be used in an amount of 0.5 to 1000 mol based on 1 mol of the compound (100 b).

The palladium compound may be palladium dichloride. The amount of the palladium compound may be a catalyst amount, and may be used in an amount of 0.0001 to 1.0 mol based on 1 mol of the compound (100 b).

The oxidation in the step (401b) may be carried out in a solvent. Examples of the solvent include water, esters, aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, carboxylic acids, ethers, halogenated hydrocarbons, nitrogen-containing polar organic compounds, nitriles, dimethyl sulfoxide, and sulfolane.

The surfactant (b) can be produced by a production method including the following steps.

A step (31b) for converting a compound represented by the formula:

R^11b-CH＝CH-(CR^2b ₂)n-(OR^3b)_p-(CR^4b ₂)_q-L-COOX^b

(in the formula, R^2b～R^4b、R^11bN, p, q and X^bAs described above. L is a single bond, -CO₂-B-*、-OCO-B-*、-CONR^6b-B-*、-NR^6bCO-B-, or-CO- (wherein-CO)₂-B-、-OCO-B-、-CONR^6b-B-、-NR^6bExcept for a carbonyl group contained in CO-B-), B is a single bond or an alkylene group having 1 to 10 carbon atoms and having or not having a substituent, and R is^6bIs H or an alkyl group having 1 to 4 carbon atoms, which may have a substituent. The number of carbon atoms of the alkylene group is more preferably 1 to 5. In addition, the above R^6bMore preferably H or methyl. is-COOX in the formula^bBonded side) to yield the following formula:

[ solution 45]

(R^2b～R^4b、L、R^11bN, p, q and X^bAs described above) as a compound (31 b).

The oxidation in step (31b) can be carried out by allowing an oxidizing agent to act on compound (30b) in the presence of water and a palladium compound, and the same conditions as those for the oxidation in step (401b) can be employed.

In any of the above production methods, the purity of the obtained compound can be improved by distilling off the solvent or performing distillation, purification, or the like after the completion of each step. Further, the compound obtained is X such as-COOH^bIn the case of the compound of H, these groups can be converted into a salt form by contacting with a base such as sodium carbonate or ammonia.

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

Low molecular weight PTFE can also be produced using the surfactant (a) or (b).

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

In addition, as the carboxylic acid type hydrocarbon-containing surfactant in the present invention, a compound represented by the general formula (1) (hereinafter also referred to as "surfactant (1)") can also be used.

General formula (1):

[ solution 46]

(in the formula, R¹～R⁵Represents H or a monovalent substituent, wherein R¹And R³At least one of them represents the general formula: -Y-R⁶A group shown, R²And R⁵At least one of them represents the general formula: -X-a, or a group of the general formula: -Y-R⁶The groups shown.

In addition, X, which is the same or different at each occurrence, represents a 2-valent linking group or bond;

A is the same or different at each occurrence and represents-COOM (M is H, a metal atom, NR)⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Is H or an organic group);

y is 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-, R⁸Is H or an organic group;

R⁶the alkyl group having 2 or more carbon atoms, which may be the same or different at each occurrence, may or may not contain at least one 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 two of them may be bonded to each other to form a ring.

Wherein R is⁶In the case where any one of the carbonyl group, ester group, amide group and sulfonyl group is not contained, X is a group containingA 2-valent linking group of at least one selected from the group consisting of a carbonyl group, an ester group, an amide group, and a sulfonyl group. )

In the formula, R¹～R⁵Represents H or a monovalent substituent, wherein R¹And R³At least one of them represents the general formula: -Y-R⁶A group shown, R²And R⁵At least one of them represents the general formula: -X-A or a group of formula: -Y-R⁶The groups shown. R ¹～R⁵Any two 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, or 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 R¹The above alkyl group of (a) preferably does not contain a carbonyl group.

In the above alkyl groups, 75% or less, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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, 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 not include a carbonyl group, further preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may not have a substituent, further more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, which 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, having orC having no substituent_1-20Alkyl, -NH of₂、-NHR⁹(R⁹Is an organic radical), -OH, -COOR⁹(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 is the same or different at each occurrence, represents a 2-valent linking group or bond.

R⁶In the case where any one of a carbonyl group, an ester group, an amide group, and a sulfonyl group is not included, X is preferably a 2-valent linking group including at least one selected from the group consisting of a carbonyl group, an ester group, an amide group, and a sulfonyl group.

X preferably contains 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-NR⁸A 2-valent linking group of at least one bond of the group consisting of CO-, C_1-10Alkylene groups, or a bond. 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, which is the same or different at each occurrence, represents-COOM (M is H, a metal atom, NR) ⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Is H or an organic group. 4R⁷May be the same or different).

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 or a metal atomOr NR⁷ ₄More preferably H, alkali metal (group 1), alkaline earth metal (group 2) or NR⁷ ₄Further, H, Na, K, Li or NH is preferable₄Further, Na, K or NH is preferable₄Particularly preferred is Na or NH₄Most preferably NH₄。

Wherein each occurrence of Y, which may be the same or different, 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 selected from the group consisting of a bond, -O-, -COO-, -OCO-, -CONR⁸-and-NR⁸The 2-valent linking group in the group consisting of CO-, more preferably a 2-valent linking group selected from the group consisting of a bond, -COO-, and-OCO-.

As R⁸Preferably H or C_1-10More preferably H or C_1-4The organic group of (3), is more preferably H.

In the formula, R ⁶The alkyl group having 2 or more carbon atoms, which may be the same or different at each occurrence, may or may not contain at least one 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 above⁶The number of carbon atoms of the organic group (2) is preferably 2 to 20, more preferably 2 to 10.

R⁶The alkyl group of (a) can contain 1 or 2 or more of at least one selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group between carbon-carbon atoms, but these groups are not contained at the terminal of the above alkyl group. R is as defined above⁶In the alkyl group (b), 75% or less, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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-R¹¹The group shown, or

A compound of the general formula: -R¹⁰-CONR⁸-R¹¹The 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_1-10More 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, further preferably 10 or less, and particularly preferably 8 or less. In addition, R¹⁰The 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.

As the surfactant (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 47]

(in the formula, R ³～R⁶X, A and Y are as described above. )

General formula (1-2):

[ solution 48]

(in the formula, R⁴～R⁶X, A and Y are as described above. )

General formula (1-3):

[ solution 49]

(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、

-OCO-R¹²-COOM、

-COO-R¹²-COOM、

-CONR⁸-R¹²-COOM、

-NR⁸CO-R¹²-COOM、

-OS(＝O)₂-R¹²-COOM。

(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, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but 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-R¹¹A 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-R¹¹A group shown by the group shown,

A compound of the general formula: -NR⁸CO-R¹⁰-CO-R¹¹The group shown, or

A compound of the general formula: -CONR⁸-R¹⁰-NR⁸CO-R¹¹The groups shown.

(in the formula, R⁸、R¹⁰And R¹¹As described above. )

In the formula, as R⁴And R⁵Independently, H or C is preferred_1-4Alkyl group of (1).

R is as defined above⁴And R⁵In the alkyl group (b), 75% or less, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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, 50% or less, and 25% or less of hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms, but 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 of (2), hydrogen bonded to carbon atom75% or less of the atoms may be substituted with a halogen atom, 50% or less may be substituted with a halogen atom, and 25% or less may be substituted with a halogen atom, but a non-halogenated alkyl group containing no halogen atom such as a fluorine atom or a chlorine atom is preferable.

The surfactant (1) can be suitably produced by a production method comprising the following steps: step (11) for converting the formula: r⁶-COOH (formula, R)⁶As described above) with a halogenating agent to give a compound of the formula: r⁶-COZ (wherein R is⁶As described above. Z is a halogen atom); and a step (12) of reacting the carboxylic acid halide with a compound represented by the formula:

[ solution 50]

(in the formula, R³～R⁵X and A are as described above. Z¹¹is-CH₂O-, -O-or-NH-) to obtain a compound of formula:

[ solution 51]

(in the formula, R³～R⁶X, A and Z¹¹As described above) of the compound (12).

R in the formula as the above acid compound³Preferably, of the formula: -Z¹¹H (in the formula, Z)¹¹As described above), or-H. R³Is represented by the general formula: -Z¹¹H, the above group is reacted with the above carboxylic acid halide in the step (12) to produce a group of the general formula: -Z¹¹-CO-R⁶(in the formula, R⁶And Z¹¹As described above).

Examples of the halogenating agent used in the step (11) include oxalyl chloride, thionyl chloride, diethylaminosulfur trifluoride (DAST), Deoxo-Fluor (Deoxo-Fluor), 1,2, 2-tetrafluoro-N, N-dimethylethylamine (TFEDMA), and the like.

Z is preferably F or Cl, more preferably Cl.

In the step (11), the ratio of the carboxylic acid to the halogenating agent is preferably 0.6 to 5.0 mol, more preferably 0.8 to 2.0 mol, based on 1 mol of the carboxylic acid, from the viewpoints of improving the yield and reducing waste. Further, it is preferably 0.5 to 10 moles, more preferably 0.6 to 5.0 moles.

The reaction in the step (11) may be carried out in a solvent. Examples of the solvent include esters, ketones, aromatic hydrocarbons, ethers, nitrogen-containing polar organic compounds, halogenated hydrocarbons, nitriles, pyridine, and mixtures thereof.

Examples of the ester include ethyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA; also known as 1-methoxy-2-acetoxypropane), and ethyl acetate is preferable.

Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol, and the like, and among them, acetone is preferable.

The aromatic hydrocarbon includes benzene, toluene, xylene, etc., and among them, benzene and toluene are preferable.

Examples of the ether include diethyl ether, tetrahydrofuran, dioxane, diethylene glycol diethyl ether, and the like, and among them, diethyl ether and tetrahydrofuran are preferable.

Examples of the nitrogen-containing polar organic compound include N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, and the like, and among them, N-dimethylformamide, N-dimethylacetamide, and N-methyl-2-pyrrolidone are preferable.

Examples of the halogenated hydrocarbon include dichloromethane, dichloroethane, chloroform, chlorobenzene, and o-dichlorobenzene, and dichloromethane and chloroform are preferable among them.

The nitrile includes acetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile and the like, and among them, acetonitrile is preferable.

The temperature of the reaction in the step (11) is preferably 0 to 150 ℃, more preferably 20 to 100 ℃. Further, it is preferably from-78 to 150 ℃ and more preferably from 0 to 100 ℃.

The pressure of the reaction in the step (11) is preferably 0 to 5MPa, more preferably 0.1 to 1.0 MPa.

The reaction time in the step (11) is preferably 0.1 to 72 hours, more preferably 0.1 to 48 hours.

In the step (12), the ratio of the acid halide to the acid compound is preferably 0.5 to 10 mol, more preferably 0.6 to 5.0 mol, and still more preferably 0.8 to 2.0 mol, based on 1 mol of the acid halide, in view of improving the yield and reducing waste.

The reaction in the step (12) is preferably carried out in the presence of an acid. Examples of the acid include sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and the like, and among them, sulfuric acid is preferable.

The amount of the acid used in the step (12) is preferably 0.00001 to 1.0 mol, more preferably 0.0001 to 1.0 mol, further preferably 0.00005 to 0.1 mol, and particularly preferably 0.001 to 0.1 mol, based on 1 mol of the carboxylic acid halide, from the viewpoints of improving the yield and reducing the waste.

The temperature of the reaction in the step (12) is preferably 0 to 150 ℃, more preferably 20 to 100 ℃.

The pressure of the reaction in the step (12) is preferably 0 to 5MPa, more preferably 0.1 to 1.0 MPa.

The reaction time in the step (12) is preferably 0.1 to 72 hours, more preferably 0.1 to 48 hours.

The surfactant (1) can be suitably produced by a production method comprising the following step (21): the formula:

[ solution 52]

(in the formula, R¹～R⁵As described above. Z¹¹is-CH₂A compound (20) represented by O-, -O-or-NH-:

[ Hua 53]

(wherein n is an integer of 1 to 5) to obtain an acid anhydride represented by the formula:

[ solution 54]

(in the formula, R¹～R⁵、Z¹¹M and n are as defined above) are given.

R in the formula as the compound (20)²Preferably, of the formula: -Z¹¹H (in the formula, Z)¹¹As described above), or-H. R²Is represented by the general formula: -Z¹¹In the case of the group represented by H, the above-mentioned group is reacted with the above-mentioned acid anhydride in the step (21) to produce a compound represented by the general formula: -Z¹¹-CO-(CH₂)_n-COOM (wherein Z¹¹M and n are as defined above). The compound (20) may be a hydrochloride, a sulfate, or the like as long as it has a structure represented by the above formula.

In the step (21), the reaction ratio of the compound (20) and the acid anhydride is preferably 0.5 to 10 moles, more preferably 0.6 to 5.0 moles, further preferably 1.2 to 10 moles, and particularly preferably 1.6 to 4.0 moles, based on 1 mole of the compound (20), in view of improving the yield and reducing waste.

The reaction in step (21) may be carried out in the presence of a base.

Examples of the base include amines, potassium hydroxide, sodium hydroxide, potassium carbonate, and the like.

Examples of the amine include tertiary amines such as trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, dimethylbenzylamine and N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine, heteroaromatic amines such as pyridine, pyrrole, uracil, collidine and lutidine, cyclic amines such as 1, 8-diaza-bicyclo [5.4.0] -7-undecene and 1, 5-diaza-bicyclo [4.3.0] -5-nonene, and pyridine and triethylamine are preferable.

The temperature of the reaction in the step (21) is preferably 0 to 150 ℃, more preferably 20 to 80 ℃. Further, it is preferably from-78 to 150 ℃ and more preferably from 0 to 100 ℃.

The pressure of the reaction in the step (21) is preferably 0 to 5MPa, more preferably 0.1 to 1 MPa.

The reaction time in the step (21) is preferably 0.1 to 72 hours, more preferably 0.1 to 48 hours.

The surfactant (1) can be suitably produced by a production method including the following steps.

Step (31) for converting the formula:

[ solution 55]

(in the formula, R⁴And R⁵As described above) with a compound of formula (la): r⁶R⁸-NH (wherein R is⁶And R⁸As described above) to give an amine of formula:

[ solution 56]

(in the formula, R⁴～R⁶And R⁸The compound (31) shown as above); and

a step (51) of reacting the compound (31) with a compound represented by the formula:

[ solution 57]

(wherein n is an integer of 1 to 5) to obtain an acid anhydride represented by the formula:

[ solution 58]

(in the formula, R⁴～R⁶、R⁸M and n are as described above) is used.

In the step (51), the reaction ratio of the compound (31) and the acid anhydride is preferably 0.5 to 10 mol, more preferably 0.6 to 4.0 mol, further preferably 1.2 to 4.0 mol, and particularly preferably 1.6 to 4.0 mol, based on 1 mol of the compound (31), from the viewpoints of improving the yield and reducing waste.

The reaction in step (51) may be carried out in the presence of a base.

Examples of the base include amines, potassium hydroxide, sodium hydroxide, potassium carbonate, and the like.

Examples of the amine include tertiary amines such as trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, dimethylbenzylamine and N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine, heteroaromatic amines such as pyridine, pyrrole, uracil, collidine and lutidine, cyclic amines such as 1, 8-diaza-bicyclo [5.4.0] -7-undecene and 1, 5-diaza-bicyclo [4.3.0] -5-nonene, and pyridine and triethylamine are preferable.

The temperature of the reaction in the step (51) is preferably-78 to 150 ℃, more preferably 0 to 150 ℃, still more preferably 0 to 100 ℃, and particularly preferably 20 to 80 ℃.

The pressure of the reaction in the step (51) is preferably 0 to 5MPa, more preferably 0.1 to 1 MPa.

The reaction time in the step (51) is preferably 0.1 to 72 hours, more preferably 0.1 to 48 hours.

In any of the above production methods, the purity of the obtained compound can be improved by distilling off the solvent or performing distillation, purification, or the like after the completion of each step. When the compound obtained is-COOH, the group can be converted into a salt form by contacting with a base such as sodium carbonate or ammonia.

The production method of the present invention may be carried out using at least one carboxylic acid type hydrocarbon-containing surfactant. In the production method of the present invention, 2 or more kinds of the above-mentioned carboxylic acid type hydrocarbon-containing surfactants may be used together as the surfactant, and any other surfactant other than the above-mentioned carboxylic acid type hydrocarbon-containing surfactants may be used together as long as it is a volatile substance or a substance that can remain in a molded article or the like made of a fluoropolymer.

In the production method of the present invention, a carboxylic acid type hydrocarbon-containing surfactant obtained by subjecting the above carboxylic acid type hydrocarbon-containing surfactant to radical treatment or oxidation treatment can be used. The production method of the present invention preferably includes a step of subjecting the carboxylic acid type hydrocarbon-containing surfactant to radical treatment or oxidation treatment.

The radical treatment may be a treatment for generating radicals in the carboxylic acid type hydrocarbon-containing surfactant, and examples of the radical treatment include the following treatments: adding deionized water and a carboxylic acid type hydrocarbon-containing surfactant into a reactor, sealing the reactor, replacing the inside of the system with nitrogen, heating and boosting the reactor, adding a polymerization initiator, stirring for a certain time, decompressing the reactor until the pressure reaches atmospheric pressure, and cooling. The oxidation treatment is a treatment in which an oxidizing agent is added to a carboxylic acid type hydrocarbon-containing surfactant. Examples of the oxidizing agent include oxygen, ozone, hydrogen peroxide, manganese (IV) oxide, potassium permanganate, potassium dichromate, nitric acid, sulfur dioxide, iron (II) sulfate heptahydrate, and the like.

The production method of the present invention may further comprise a step of adjusting the pH of the aqueous medium containing the carboxylic acid type hydrocarbon-containing surfactant to alkaline. The basic property means that the pH is preferably 7.1 or more, more preferably 7.5 or more, further preferably 8.0 or more, particularly preferably 8.5 or more, and further preferably 9.0 or more. By adjusting the pH to be alkaline, the surface active ability can be improved. The step of adjusting the pH may be performed before or after the step of subjecting the carboxylic acid type hydrocarbon-containing surfactant to radical treatment or oxidation treatment, and is preferably performed thereafter. The method of adjusting the pH is not particularly limited, and a method of adding a pH adjuster to the aqueous medium may be mentioned. As the pH adjuster, ammonia, an aqueous NaOH solution, an aqueous potassium hydroxide solution, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium phosphate, potassium phosphate, sodium citrate, potassium citrate, ammonium citrate, sodium gluconate, potassium gluconate, ammonium gluconate, or the like can be used. The pH can be measured by a pH meter manufactured by orion.

Examples of the other surfactants include nonionic surfactants and silicone surfactants.

The nonionic surfactant is preferably at least one selected from the group consisting of:

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

(wherein Rf²⁴¹Is a partially or 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 R²⁴²Different from each other) of the compounds represented by (a) above,

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 R²⁵²Different from each other) of the block polymers shown in (a),

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

general formula (260): r²⁶¹ _m-Siso (OR)²⁶²)_4-m

(in the formula, R²⁶¹Is an alkyl group having 1 to 12 carbon atoms, R²⁶²An alkyl group having 1 to 4 carbon atoms, and m is an integer of 1 to 3).

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. Among them, polyoxyethylene-polyoxypropylene block polymers and polyoxyethylene-polyoxybutylene block polymers can be exemplified, and not only A-B type block polymers but also A-B-A type block polymers are preferably exemplified. It is further preferable that a stable fluoropolymer dispersion can be prepared at a high concentration by using a polyoxyethylene-polyoxypropylene block polymer or a polyoxypropylene-polyoxyethylene-polyoxypropylene block polymer. Further, when the content of the polyoxyethylene segment is 10 to 50%, it is considered that generation of aggregates due to re-aggregation is small, and therefore it is preferable; further, when the content is 20 to 40%, a low-viscosity fluoropolymer dispersion can be prepared, which is preferable. The molecular weight is not particularly limited as long as it is 1000 to 7000 g/mol; further, particularly when the molecular weight is 2500 to 6500g/mol, a dispersion having a low viscosity and excellent dispersibility can be prepared.

As the Silicone-based surfactant, Silicone Surfactants, r.m. hill, MarcelDekker, inc., ISBN: 0-8247-00104. The structure of silicone-based surfactants contains well-defined hydrophobic and hydrophilic moieties. The hydrophobic moiety comprises 1 or more dihydrocarbylsiloxane units, where the substituents on the silicone atom are entirely hydrocarbons.

When the carbon atom of the hydrocarbon group can be substituted with a halogen such as fluorine, these siloxane surfactants can also be considered as hydrocarbon surfactants in the sense that they are completely substituted with a hydrogen atom, i.e., the monovalent substituent on the carbon atom of the hydrocarbon group is hydrogen.

The hydrophilic moiety of the silicone surfactant may include 1 or more polar moieties including ionic groups, such as sulfate, sulfonate, phosphonate, phosphate, carboxylate, carbonate, sulfosuccinate, taurate (as a free acid, salt, or ester), phosphine oxide, betaine copolyol, and quaternary ammonium salt. The ionic hydrophobic moiety may also include ionically functionalized siloxane grafts.

Examples of such silicone surfactants include polydimethylsiloxane-graft- (meth) acrylate, polydimethylsiloxane-graft-polyacrylate, and polydimethylsiloxane-grafted quaternary amine.

The polar portion of the hydrophilic portion of the silicone-based surfactant may include polyethers such as Polyoxyethylene (PEO) and mixed polyoxyethylene/polyoxypropylene polyether (PEO/PPO); monosaccharides and disaccharides; and nonionic groups formed from water-soluble heterocycles such as pyrrolidone. The ratio of ethylene oxide to propylene oxide (EO/PO) may vary in the mixed polyoxyethylene/polyoxypropylene polyether.

The hydrophilic portion of the silicone-based surfactant may also comprise a combination of ionic and nonionic moieties. Examples of such moieties include polyethers and polyols functionalized with ionic terminals or randomly functionalized. Preferred for the practice of the present invention are silicone-based, i.e., nonionic silicone-based surfactants having a nonionic moiety.

The arrangement of the hydrophobic and hydrophilic portions of the structure of the silicone surfactant may be in the form of a diblock polymer (AB), a triblock polymer (ABA) (here, "B" represents the siloxane portion of the molecule), or a multiblock polymer. Alternatively, the silicone-based surfactant may comprise a graft polymer.

Silicone surfactants are also disclosed in U.S. Pat. No. 6,841,616.

Examples of the silicone-based anionic hydrocarbon surfactant include Noveon (registered trademark) available from Lubrizol advanced materials, Inc., and SilSense available from Consumer Specialties^TMPE-100 Silicone, SilSense^TMCA-1 silicone, and the like.

Examples of the anionic hydrocarbon surfactant include a sulfosuccinate surfactant Lankropol (registered trademark) K8300 of Akzo Nobel Surface Chemistry LLC.

Examples of the sulfosuccinate hydrocarbon surfactant include diisodecyl sodium sulfosuccinate, (Emulsogen (registered trademark) SB10 from Clariant), diisotridecyl sodium sulfosuccinate (Polirol (registered trademark) TR/LNA from cesapini chemicals), and the like.

The hydrocarbon surfactant may also be polyFox (registered trade name) by Omnova Solutions, IncTrademark) surfactant (PolyFox)^TMPF-156A、PolyFox^TMPF-136A, etc.).

When the carboxylic acid type hydrocarbon-containing surfactant is used in combination with another surfactant, the carboxylic acid type hydrocarbon-containing surfactant is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, particularly preferably 80% by mass or more, and particularly preferably 90% by mass or more, relative to the total amount of the surfactants. In the polymerization step, the carboxylic acid type hydrocarbon-containing surfactant is preferably not substantially used in combination with other surfactants, and the other surfactants are preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.1% by mass or less of the total amount of the surfactants.

The method for producing a fluoropolymer of the present invention comprises a step of obtaining a fluoropolymer by polymerizing a fluoromonomer in an aqueous medium. The polymerization may be emulsion polymerization.

The fluorine-containing monomer preferably has at least 1 double bond.

The fluorine-containing monomer is preferably selected from the group consisting of tetrafluoroethylene [ TFE ]]Hexafluoropropylene [ HFP ]]Chlorotrifluoroethylene [ CTFE ]]Vinyl fluoride, vinylidene fluoride [ VDF ]]Trifluoroethylene, fluoroalkyl vinyl ethers, fluoroalkyl ethylenes, trifluoropropene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, general formula (100): CH (CH)₂＝CFRf¹⁰¹(wherein Rf¹⁰¹A linear or branched fluoroalkyl group having 1 to 12 carbon atoms), a fluorovinyl heterocyclic compound, and a monomer providing a crosslinking site.

The fluorinated alkyl vinyl ether is preferably at least one selected from the group consisting of the following fluorine-containing monomers:

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

(wherein Rf¹¹¹Represents a perfluoroorganic group), a fluorine-containing 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 fluorine-containing monomer,

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

(wherein Rf¹³¹A linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, a linear or branched perfluorooxyalkyl group having 2 to 6 carbon atoms and containing 1 to 3 oxygen atoms) as a fluorine-containing monomer,

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), 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 Z¹⁵³Same or different, represent-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).

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 aforementioned perfluoroorganic group may have an ether oxygen.

Rf is an example of the fluorine-containing monomer represented by the general formula (110)¹¹¹Is a fluorine-containing monomer of perfluoroalkyl group with 1-10 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 fluorine-containing monomer represented by the general formula (110) may further include Rf in the general formula (110)¹¹¹Is a C4-9 perfluoro (alkoxyalkyl) monomer, Rf¹¹¹Is of the formula:

[ chemical 59]

(wherein m represents 0 or an integer of 1 to 4), and Rf¹¹¹Is of the formula:

[ solution 60]

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

Among the fluorine-containing monomers represented by the general formula (110), preferred is a fluorine-containing monomer represented by the general formula (160): CF (compact flash)₂＝CF-ORf¹⁶¹

(wherein Rf¹⁶¹A perfluoroalkyl group having 1 to 10 carbon atoms). Rf¹⁶¹Preferably, the perfluoroalkyl group has 1 to 5 carbon atoms.

The fluorinated alkyl vinyl ether is preferably at least one selected from the group consisting of fluorine-containing monomers represented by the general formulae (160), (130) and (140).

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

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

The fluorine-containing 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.

The fluorine-containing 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 one of the group consisting of.

As the fluorine-containing monomer represented by the general formula (100), Rf is preferable¹⁰¹A fluorine-containing monomer which is a linear fluoroalkyl group, 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 fluorine-containing monomer represented by the general formula (100) include CH₂＝CFCF₃、CH₂＝CFCF₂CF₃、CH₂＝CFCF₂CF₂CF₃、CH₂＝CFCF₂CF₂CF₂H、CH₂＝CFCF₂CF₂CF₂CF₃Etc., wherein CH is preferred₂＝CFCF₃Shown in2,3,3, 3-tetrafluoropropene.

As the fluoroalkylethylene, preferred is a compound represented by the general formula (170): CH (CH)₂＝CH-(CF₂)_n-X¹⁷¹

(in the formula, X¹⁷¹H or F, n is an integer of 3 to 10), more preferably selected from the group consisting of CH₂＝CH-C₄F₉And CH₂＝CH-C₆F₁₃At least one of the group consisting of.

As the monomer providing the crosslinking site, at least one 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 CH₃，R_f ¹⁸¹Is a fluoroalkylene, perfluoroalkylene, fluoro (poly) oxyalkylene or perfluoro (poly) oxyalkylene radical, R ¹⁸¹Is a hydrogen atom or CH₃，X¹⁸³Is an iodine atom or a bromine atom), a fluorine-containing monomer,

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

(in the formula, X¹⁹¹And X¹⁹²Independently a hydrogen atom, a fluorine atom or CH₃，R_f ¹⁹¹Is a fluoroalkylene, perfluoroalkylene, fluoropolyoxyalkylene or perfluoropolyoxyalkylene radical, X¹⁹³Is an iodine atom or a bromine atom), a fluorine-containing monomer,

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) The fluorine-containing monomer, 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-CH₂OH) and a fluorine-containing monomer, and

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

(in the formula, R²²¹、R²²²、R²²³、R²²⁴、R²²⁵And R²²⁶The same or different, and is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z²²¹Is a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, an alkylene group or oxyalkylene group having 1 to 10 carbon atoms, which is at least partially fluorinated, having or not having an oxygen atom

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

(wherein Q is an alkylene group or an 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).

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。

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

[ solution 61]

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

[ solution 62]

(in the formula, Z²³¹And Z²³²Independently F or a fluoroalkyl group having 1 to 3 carbon atoms)).

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.

In the step, the fluorine-containing monomer may be polymerized with a non-fluorine-containing monomer. Examples of the non-fluorine-containing monomer include hydrocarbon monomers reactive with the fluorine-containing monomer. Examples of the hydrocarbon-based 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 versatate, 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; alkyl allyl esters such as ethyl allyl ester, propyl allyl ester, butyl allyl ester, isobutyl allyl ester, and cyclohexyl allyl ester; and so on.

The non-fluorine-containing monomer may be a hydrocarbon monomer having a functional group (excluding a monomer 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; non-fluorine-containing monomers having amide groups such as (meth) acrylamide and methylolacrylamide; and so on.

In the above step, particles of the desired fluoropolymer can be obtained by polymerizing 1 or 2 or more kinds of the above-mentioned fluoromonomers.

The production method of the present invention may use a nucleating agent. 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 diameter can be obtained as compared with the case where polymerization is carried out in the absence of the above nucleating agent.

Examples of the nucleating agent include perfluoropolyether (PFPE) acid or a salt thereof, and a nonionic surfactant (for example, a nonionic hydrocarbon surfactant). 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, and the particle size distribution can be adjusted by adding the nucleating agent during the polymerization.

The above perfluoropolyether (PFPE) acid or salt thereof may have: an arbitrary 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 a repeating unit represented by the following 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.polymer sci.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 above-mentioned PFPE acid or salt thereof may further 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 salt thereof may have different groups at each terminal. With monofunctional PFPE, the other end of the molecule is usually perfluorinated and may also contain a hydrogen or chlorine atom. The above-mentioned PFPE acid or salt thereof has at least 2 ether oxygens, preferably at least 4 ether oxygens, and even more preferably at least 6 ether oxygens. Preferably at least 1 of the carbon fluoride groups spaced apart from the ether 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 ether oxygen have 2 or 3 carbon atoms. In addition, the above-mentioned PFPE acid or a 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 or salt thereof having an acid group at 1 terminal or both terminals in an amount of 2 or more can be used in the production process 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 nucleating agent is preferably a nonionic surfactant. The nonionic surfactant may not contain an aromatic moiety.

Examples of the nonionic surfactant include those represented by the following general formula (i)

R³-O-A¹-H (i)

(in the formula, R³Is a linear or branched primary or secondary alkyl group having 8 to 18 carbon atoms, A¹Is a polyoxyalkylene chain).

R³The number of carbon atoms of (A) is preferably 10 to 16, more preferably 12 to 16. If R is³When the number of carbon atoms of (2) is 18 or less, good dispersion stability of the aqueous dispersion can be easily obtained. In addition if R³If the number of carbon atoms exceeds 18, the flow temperature is high, and therefore, handling is difficult. If R is³When 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 ethylene oxide and propylene oxide. Is a polyoxyalkylene chain having 5 to 20 average repeating numbers of oxyethylene groups and 0 to 2 average repeating numbers of oxypropylene groups, and is a hydrophilic group. The ethylene oxide unit number may comprise any of a broad or narrow monomodal distribution, as typically provided, or a broader or bimodal distribution obtained by blending. When the average repeating number of the oxypropylene group exceeds 0, the oxyethylene group and the oxypropylene group in the polyoxyalkylene chain may be arranged in a block form or in a random form.

From the viewpoint of viscosity and stability of the aqueous dispersion, a polyoxyalkylene chain comprising an average repeating number of oxyethylene groups of 7 to 12 and an average repeating number of oxypropylene groups of 0 to 2 is preferred. Especially if A¹It is preferable that the acrylic resin composition has an oxypropylene group of 0.5 to 1.5 on average because low foaming property is good.

More preferably R³Is (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 polyoxyethylene alkyl ether include C₁₃H₂₇-O-(C₂H₄O)₁₀-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. Examples of commercially available products of the polyoxyethylene alkyl ether include Genapol X080 (product name, manufactured by Clariant Co., Ltd.), Noigen TDS series (first Industrial pharmaceutical Co., Ltd.) such as Noigen TDS-80 (product name), Leocol TD series (LION Co., Ltd.) such as Leocol TD-90 (product name), LIONOL (registered trademark) TD series (manufactured by LION Co., Ltd.), T-Det A series (manufactured by Harcross Chemicals Co., Ltd.) such as T-Det A138 (product name), TERGITOL (registered trademark) 15S series (manufactured by Tao Co., Ltd.)Manufactured), and the like.

The above nonionic surfactants are also preferably ethoxylates of 2,6, 8-trimethyl-4-nonanol having an average of about 4 to about 18 ethylene oxide units, ethoxylates of 2,6, 8-trimethyl-4-nonanol having an average of about 6 to about 12 ethylene oxide units, or mixtures thereof. Nonionic surfactants of this type are also commercially available, for example, 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 alkylphenyl ether nonionic compound include those represented by the following general formula (ii)

R⁴-C₆H₄-O-A²-H (ii)

(in the formula, R⁴Is a linear or branched primary or secondary alkyl group having 4 to 12 carbon atoms, A²Is a polyoxyalkylene chain). Specific examples of the polyoxyethylene alkylphenyl ether nonionic compound include TRITONX-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. Examples of suitable polyol compounds containing at least 1 long chain moiety include alkyl glycosides, modified alkyl glycosides, sugar esters, and combinations thereof. Examples of the saccharide include, but are not limited to, monosaccharides, oligosaccharides, 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 the oligosaccharide 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 cyclic compound containing 4 carbon atoms and 1 hetero atom (typically oxygen or sulfur, preferably oxygen atom), or a six-membered ring cyclic compound containing 5 carbon atoms and the above-mentioned 1 hetero atom, preferably oxygen atom. They further contain at least 2 or at least 3 hydroxyl groups (-OH groups) bonded to carbon ring atoms. Typically, to make ether or ester linkages between long chain residues and sugar moieties, sugars are modified in the following ways: more than 1 of the hydrogen atoms of the hydroxyl (and/or hydroxyalkyl) groups bonded to carbon ring atoms are substituted with long chain residues.

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 with the above-mentioned long chain moiety. Specific examples of the sugar-based polyol compound include glycosides, sugar esters, sorbitan esters, and mixtures and combinations thereof.

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

[ solution 63]

(wherein x represents 0, 1, 2, 3, 4, or 5, 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 representing the pyranose form, but it will be appreciated that other sugars or sugars which are the same sugar but different mirror image isomers or diastereoisomers may also be used.

The alkyl glucosides can be obtained, for example, by acid-catalyzed reaction of glucose, starch, or n-butyl glucoside with an aliphatic alcohol, in the typical case a mixture of various alkyl glucosides being 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 Dusseldorf Cognis GmbH, Germany under the trade name GLUCOPON or DISPONIL.

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, hydrocarbon-containing siloxane surfactants, preferably hydrocarbon surfactants, wherein the hydrocarbon group is completely substituted with a hydrogen atom when the hydrocarbon group can be substituted with a halogen such as fluorine, and these siloxane surfactants can also be considered as hydrocarbon surfactants, i.e., monovalent substituents on the hydrocarbon group are hydrogen.

The polymerization step is preferably a step of polymerizing the fluorine-containing monomer in an aqueous medium substantially not containing the nonionic surfactant.

The aqueous medium preferably contains substantially no nonionic surfactant before the start of polymerization.

For example, the amount of the nonionic surfactant is preferably 10ppm or less, more preferably 1ppm or less, further preferably 0.1ppm or less, particularly preferably 0.01ppm or less, and particularly preferably 0.001ppm or less, relative to the aqueous medium.

The term "before the start of polymerization" means before the pressure of the pressurized fluorine-containing monomer is reduced or before the flow rate of the fluorine-containing monomer (for example, 0.01 g/hr or more) is increased by adding a polymerization initiator to the aqueous medium.

When TFE is used as a fluorine-containing monomer to produce polytetrafluoroethylene [ PTFE ] as a fluorine-containing polymer, a (polyfluoroalkyl) ethylene (a) and/or a comonomer (b) having a monomer reactivity ratio of rTFE of 0.1 to 8 are contained in an emulsion polymerization system so as to be 0.001 to 0.01 mass% relative to the amount of final PTFE to be produced at the start of emulsion polymerization of TFE, whereby a PTFE aqueous emulsion can be produced which has high stability of the PTFE aqueous emulsion to the extent that subsequent processability, moldability and the like are not impaired and which can give a molded article having high heat resistance.

The above reactivity ratio can be calculated as follows: the composition of the resulting polymer immediately after the start of copolymerization was determined by copolymerizing TFE with a comonomer in 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 0.78MPa and a temperature of 70 ℃. 0.05g, 0.1g, 0.2g, 0.5g and 1.0g of a comonomer were fed into the reactor, respectively, and 0.072g of ammonium persulfate (20 ppm relative to water) was fed thereto, and TFE was continuously fed so as to maintain a polymerization pressure of 0.78 MPa. 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 precipitate a 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.

In the production method of the present invention, in addition to the surfactant and other compounds having a surface-active ability to be used as desired, additives for stabilizing the respective compounds may be used. 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 to be completely separated from the aqueous PTFE emulsion after emulsion polymerization of TFE and not to become a contaminating component.

In the production process of the present invention, the polymerization may be initiated by pressurizing the monomer into the polymerization reactor and adding a polymerization initiator. The monomer may be introduced before or after the addition of the polymerization initiator, or may be introduced simultaneously with the addition of the polymerization initiator.

For example, in the production method of the present invention, polymerization is carried out as follows: the polymerization can be carried out by charging an aqueous medium, the above surfactant and, if necessary, other additives into a polymerization reactor, pressurizing the monomer, stirring the contents of the reactor, maintaining the reactor at a predetermined polymerization temperature, and then adding a predetermined amount of a polymerization initiator to initiate the polymerization reaction. That is, in the polymerization step, a polymerization initiator may be added to initiate polymerization.

Alternatively, the polymerization may be carried out by charging the aqueous medium, the surfactant and, if necessary, other additives into a polymerization reactor, stirring the contents of the reactor, maintaining the reactor at a predetermined polymerization temperature, subsequently adding a predetermined amount of a polymerization initiator, and then pressing the monomer into the polymerization reactor to initiate the polymerization reaction. That is, in the polymerization step, the polymerization may be initiated by pressing the monomer.

After the polymerization reaction is started, a monomer, a polymerization initiator, a chain transfer agent, the surfactant, and the like may be added thereto according to the purpose.

In the polymerization step, 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.

In the polymerization step, the polymerization temperature is preferably 30 ℃ or higher, more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is preferably 100 ℃ or lower, more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower.

The polymerization pressure is preferably 0.5MPa or more, more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is preferably 5.0MPa or less, more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The preferable combination of the polymerization temperature and the polymerization pressure is, for example, a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 3.0MPa or less.

In the polymerization step, the carboxylic acid type hydrocarbon-containing surfactant is preferably added in an amount of 0.0001 to 10% by mass based on 100% by mass of the aqueous medium in the total amount added. The lower limit is more preferably 0.001% by mass, still more preferably 0.01% by mass, and particularly preferably 0.1% by mass. The upper limit is more preferably 1.0% by mass, still more preferably 0.50% by mass, and particularly preferably 0.35% by mass. If the amount is less than 0.0001% by mass, the emulsion stability may be insufficient, and if it exceeds 10% by mass, the effect commensurate with the amount added may not be obtained, and instead, 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.

In the above polymerization step, the amount of the carboxylic acid type hydrocarbon-containing surfactant at the initial stage of polymerization is preferably more than 50ppm based on the aqueous medium. The amount of the carboxylic acid type hydrocarbon-containing surfactant is more preferably 60ppm or more, further preferably 70ppm or more, particularly preferably 80ppm or more, further preferably 90ppm or more, and particularly preferably 100ppm or more, based on the aqueous medium.

The start of polymerization can be confirmed by reducing the pressure of the pressurized fluoromonomer or by the flow rate of the fluoromonomer (for example, 0.01 g/hr or more).

The term "initial stage of polymerization" means, for example, the time from the start of polymerization until the filling amount of the fluorine-containing monomer to the aqueous medium reaches 10 g/L.

In the polymerization step, the carboxylic acid type hydrocarbon-containing surfactant is preferably added to the aqueous medium before the polymerization is started.

In the polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less. The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at the above concentration of 0.2% by mass or less, further preferably at the above concentration of 0.1% by mass or less, and particularly preferably added at the same time as the start of polymerization.

The concentration is a concentration based on the total of the aqueous medium and the fluoropolymer particles.

The method for producing a fluoropolymer of the present invention preferably further comprises the step of continuously adding the carboxylic acid type hydrocarbon-containing surfactant. The continuous addition of the carboxylic acid type hydrocarbon-containing surfactant means, for example, that the carboxylic acid type hydrocarbon-containing surfactant is not added all at once but added over time or in portions. The above carboxylic acid type hydrocarbon-containing surfactant may be added in the form of an aqueous solution containing the carboxylic acid type hydrocarbon-containing surfactant and water.

In the method for producing a fluoropolymer according to the present invention, the step of continuously adding the carboxylic acid type hydrocarbon-containing surfactant preferably starts adding the carboxylic acid type hydrocarbon-containing surfactant to the aqueous medium when the solid content of the fluoropolymer formed in the aqueous medium is 0.5% by mass or less. The carboxylic acid type hydrocarbon-containing surfactant is preferably added at the time when the solid content is 0.3% by mass or less, more preferably at the time when the solid content is 0.2% by mass or less, still more preferably at the time when the solid content is 0.1% by mass or less, and particularly preferably at the same time as the polymerization starts. The solid content is a concentration based on the total of the aqueous medium and the fluoropolymer.

In the step of continuously adding the carboxylic acid type hydrocarbon-containing surfactant, the amount of the carboxylic acid type hydrocarbon-containing surfactant added is preferably 0.0001 to 10% by mass based on 100% by mass of the aqueous medium. The lower limit is preferably 0.001 mass%, more preferably 0.01 mass%, and still more preferably 0.1 mass%. The upper limit is preferably 10% by mass, more preferably 1.0% by mass, and still more preferably 0.50% by mass. If less than 0.0001 mass%, the dispersing power may be insufficient; if the amount is more than 10% by mass, the effect commensurate with 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.

In the above polymerization step, it is preferable to polymerize the fluorine-containing monomer in the substantial absence of the fluorine-containing surfactant.

Conventionally, a fluorinated surfactant has been used for polymerization of a fluoropolymer, but the production method of the present invention can obtain a fluoropolymer by using the carboxylic acid type hydrocarbon-containing surfactant without using a fluorinated surfactant.

In the present specification, "substantially in the absence of a fluorosurfactant" means that the fluorosurfactant is 10ppm or less, preferably 1ppm or less, more preferably 100ppb or less, further preferably 10ppb or less, and further preferably 1ppb or less with respect to the aqueous medium.

Examples of the fluorosurfactant include anionic fluorosurfactants.

The anionic fluorosurfactant may be a surfactant containing fluorine atoms, for example, in which the total carbon number of the portion excluding the anionic group 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 of the above-mentioned fluorosurfactant other than cations. 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 fluorosurfactant in octanol/a concentration of the fluorosurfactant in water when a mixed solution of octanol/water (1: 1) containing the fluorosurfactant is phase-separated ].

The LogPOW is calculated as follows: in the column: TOSOH ODS-120T column

Manufactured by tokyo corporation), eluent: acetonitrile/0.6 mass% HClO4 water 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, calibration curves were prepared for each elution time and the known octanol/water partition coefficients, and the elution time of HPLC in the sample solution was calculated based on the calibration curves.

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, Xⁿ⁰H, Cl or F. Rfⁿ⁰The alkylene group may contain 1 or more ether bonds and may have 3 to 20 carbon atoms in a chain, branched or cyclic manner, wherein part or all of H is substituted by F, and part of H may be substituted by Cl. Y is⁰Is an anionic group).

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

M is H, a metal atom, NR⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, 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_1-10May also be H or C_1-4May also be H or C_1-4Alkyl group of (1).

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

Rf aboveⁿ⁰In (b), 50% or more of H may be substituted by fluorine.

As the above general formula (N)⁰) Examples of the compound 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, Y⁰Is a substance defined above); 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，Y⁰Is a substance defined above); 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, and Rfⁿ³Is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, q is 0 or 1, Y⁰Is a substance defined above); the following general formula (N)⁴)：

Rfⁿ⁴-O-(CYⁿ¹Yⁿ²)_pCF₂-Y⁰(N⁴)

(wherein Rfⁿ⁴Is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms and containing an ether bond, Yⁿ¹And Yⁿ²Identical or different, is H or F, p is 0 or 1, Y⁰Is a substance defined above); and the following general formula (N)⁵)：

[ solution 64]

(in the formula, Xⁿ²、Xⁿ³And Xⁿ⁴May be the same or different and is HF, or a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms which may contain 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 is ⁰Are defined above. Wherein, Xⁿ²、Xⁿ³、Xⁿ⁴And Rfⁿ⁵The total number of carbon atoms of (2) is 18 or less).

As the above general formula (N)⁰) The compounds shown, more specifically, examples thereof include a perfluorocarboxylic acid (I) represented by the following general formula (I), an ω -H perfluorocarboxylic acid (II) represented by the following general formula (II), a perfluoropolyether carboxylic acid (III) represented by the following general formula (III), a perfluoroalkylalkylalkylene carboxylic acid (IV) represented by the following general formula (IV), a perfluoroalkoxyfluorocarboxylic acid (V) represented by the following general formula (V), a perfluoroalkylsulfonic acid (VI) represented by the following general formula (VI), an ω -H perfluorosulfonic acid (VII) represented by the following general formula (VII), a perfluoroalkylalkylalkylene sulfonic acid (VIII) represented by the following general formula (VIII), an alkylalkylalkylene carboxylic acid (IX) represented by the following general formula (IX), a fluorocarboxylic acid (X) represented by the following general formula (X), an alkoxyfluorosulfonic acid (XI) represented by the following general formula (XI), and a compound (XII) represented by the.

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, M is H, a metal atom, NR⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Is H or an organic group).

The above-mentioned 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 Rf¹A perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer of 0 to 3, and M is as defined above).

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

Rf²(CH₂)_n4Rf³COOM (IV)

(wherein Rf²Is a perfluoroalkyl group having 1 to 5 carbon atoms, Rf³A 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 alkoxy fluorocarboxylic acid (V) is represented by the following general formula (V)

Rf⁴-O-CY¹Y²CF₂-COOM (V)

(wherein Rf⁴Is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms and containing an ether bond, Y¹And Y²Identical or different, H or F, M being a substance as defined above).

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 Rf⁵A perfluoroalkyl group having 1 to 13 carbon atoms, n7 is an integer of 1 to 3, and M is defined as above).

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

Rf⁶(CH₂)_n8COOM (IX)

(wherein Rf⁶A 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 defined as above).

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, and Rf⁸A linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, wherein M is as defined above).

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

Rf⁹-O-CY¹Y²CF₂-SO₃M (XI)

(wherein Rf⁹Is a linear or branched C1-12 alkyl group which may contain an ether bond and may be partially or fully fluorinated and may contain chlorine, and Y is¹And Y²Identical or different, H or F, M being a substance as defined above).

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

[ solution 65]

In the formula, X¹、X²And X³H, F and a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms and containing an ether bond, and Rf ¹⁰Is a C1-3 perfluoroalkylene group, L is a linking group, Y⁰Anionic group).

Y⁰Can be-COOM, -SO₂M or-SO₃M, may also be-SO₃M or COOM (wherein M is 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.

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

In the above polymerization step, a polymerization initiator is preferably added to the aqueous medium.

The polymerization initiator is not particularly limited as long as it can generate radicals in the above polymerization temperature range, and known oil-soluble and/or water-soluble polymerization initiators can be used. Further, the polymerization may be 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 as representative: 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, 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 so on.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples thereof include ammonium salts, potassium salts, sodium salts, t-butyl peroxymaleate, t-butyl hydroperoxide, and the like of persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, percarbonic acid, 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.

As the 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 such as ammonium persulfate and potassium persulfate; organic peroxides such as disuccinic acid peroxide and glutaric acid peroxide; permanganates such as permanganic acid, ammonium permanganate, alkali metal salts of permanganic acid, and the like; manganese (C) triacetate₆H₉MnO₆) (ii) a Cerium (IV) salts such as ammonium cerium nitrate and ammonium cerium sulfate; bromic acid or its salt such as bromic acid, ammonium bromate, alkali metal salt of bromic acid, and alkaline earth metal salt of bromic acid. Potassium permanganate is preferred as the permanganate.

Examples of the reducing agent include dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and salts thereof; a diimine; and the like.

As the dicarboxylic acid or a salt thereof, oxalic acid or a salt thereof is preferable.

As the bromic acid or a salt thereof, potassium bromate is preferable.

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.

The redox initiator is preferably a permanganate or a salt thereof, a persulfate, manganese triacetate, a cerium (IV) salt, or a bromic acid or a salt thereof as the oxidizing agent, or a dicarboxylic acid or a salt thereof, or a diimine as the reducing agent.

More preferably, the oxidizing agent is permanganic acid or a salt thereof, a persulfate, or bromic acid or a salt thereof, and the reducing agent is dicarboxylic acid or a salt thereof.

The above combination is more preferably a combination of permanganic acid or a salt thereof and dicarboxylic acid or a salt thereof, and particularly preferably a combination of potassium permanganate and oxalic acid, from the viewpoint of oxidation-reduction potential.

Examples of the redox initiator include potassium permanganate/oxalic acid, manganese triacetate/oxalic acid, cerium ammonium nitrate/oxalic acid, and the like in combination, and potassium permanganate/oxalic acid is particularly preferable.

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 polymerization step, it is preferable to add 0.1ppm or more of a redox initiator to the aqueous medium from the viewpoint of the reaction rate. The amount of the redox initiator to be added is more preferably 1ppm or more, still more preferably 5ppm or more, and particularly preferably 10ppm or more, based on the aqueous medium. From the viewpoint of adjusting the molecular weight of the fluoropolymer, the amount is preferably 1000ppm or less, more preferably 500ppm or less, based on the aqueous medium.

In the above polymerization step, a radical polymerization initiator may be used as the polymerization initiator. As the radical polymerization initiator, peroxides are preferable. Examples of the radical polymerization initiator include the above-mentioned oil-soluble radical polymerization initiator and water-soluble radical polymerization initiator, and the above-mentioned water-soluble radical polymerization initiator is preferable. The water-soluble radical polymerization initiator is more preferably a peroxide, and still more preferably a persulfate, an organic peroxide, or a mixture thereof. Examples of the persulfate include ammonium persulfate and potassium persulfate. Examples of the organic peroxide include disuccinic acid peroxide and dipentanoic acid peroxide. More preferably ammonium persulfate and disuccinic acid peroxide. In the polymerization step, for example, 5ppm or more of ammonium persulfate is preferably added to the aqueous medium, more preferably 10ppm or more, further preferably 20ppm or more, further preferably 30ppm or more, particularly preferably 40ppm or more, particularly preferably 50ppm or more, particularly preferably 80ppm or more, and particularly preferably 100ppm or more. In the above polymerization step, a radical polymerization initiator may be continuously or intermittently added after the initiation of polymerization.

The aqueous medium is a reaction medium for carrying out the polymerization and is a liquid containing water. 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 aqueous medium, water is preferably 50% by mass or more, more preferably 80% by mass or more, and most preferably 100% by mass.

Examples of preferable conditions for the polymerization step are described below.

In the polymerization step, the polymerization temperature is usually 5 to 120 ℃ and the polymerization pressure is usually 0.05 to 10 MPa. 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.

In the polymerization step, the polymerization temperature is preferably 30 ℃ or higher, more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is preferably 100 ℃ or lower, more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower.

The polymerization pressure is preferably 0.5MPa or more, more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is preferably 5.0MPa or less, more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The preferable combination of the polymerization temperature and the polymerization pressure is, for example, a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 3.0MPa or less.

In the polymerization step, the polymerization temperature is preferably from 30 ℃ to 100 ℃ and the polymerization pressure is preferably from 0.5MPa to 5.0 MPa.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

In the polymerization step, the polymerization temperature is preferably 30 to 100 ℃, the polymerization pressure is preferably 0.5 to 5.0MPa, and the polymerization initiator is preferably a redox initiator.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The redox initiator is more preferably a combination of permanganic acid or a salt thereof and dicarboxylic acid or a salt thereof, and particularly preferably a combination of potassium permanganate and oxalic acid.

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by weight or less, wherein the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, and the polymerization initiator is a redox initiator.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, the polymerization initiator is a redox initiator, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group). The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0 MPa.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the polymerization initiator is a redox initiator, the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, and the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less.

The redox initiator is more preferably a combination of permanganic acid or a salt thereof and dicarboxylic acid or a salt thereof, and particularly preferably a combination of potassium permanganate and oxalic acid.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably when the concentration of the fluoropolymer particles is 0.2% by mass or less, still more preferably when the concentration is 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the polymerization step, it is preferable that the polymerization initiator is a redox initiator, the polymerization temperature is 30 to 100 ℃ and the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started.

The redox initiator is more preferably a combination of permanganic acid or a salt thereof and dicarboxylic acid or a salt thereof, and particularly preferably a combination of potassium permanganate and oxalic acid.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃ and the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0MPa, and before the start of the polymerization or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in the carboxyl group).

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization. The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the polymerization step, the polymerization pressure is preferably 1.5MPa or more, and the polymerization initiator is preferably a redox initiator.

The polymerization pressure is 1.8MPa or more (more preferably 2.0MPa or more, and particularly preferably 2.3MPa or more).

The redox initiator is more preferably a combination of permanganic acid or a salt thereof and dicarboxylic acid or a salt thereof, and particularly preferably a combination of potassium permanganate and oxalic acid.

In the polymerization step, the polymerization temperature is preferably 30 to 100 ℃, the polymerization pressure is preferably 0.5 to 5.0MPa, and the polymerization initiator is a radical polymerization initiator.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The radical polymerization initiator is preferably a persulfate, an organic peroxide, or a mixture thereof, and more preferably ammonium persulfate or disuccinic acid peroxide.

In the above polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, the polymerization initiator is a radical polymerization initiator, and the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36 wt% or less.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, the polymerization initiator is a radical polymerization initiator, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group). The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0 MPa.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium when the polymerization initiator is a radical polymerization initiator, the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, and the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less.

The radical polymerization initiator is preferably a persulfate, an organic peroxide, or a mixture thereof, and more preferably ammonium persulfate or disuccinic acid peroxide.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization.

In the polymerization step, it is preferable that the polymerization initiator is a radical polymerization initiator, the polymerization temperature is 30 to 100 ℃, the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium before the polymerization is started.

The radical polymerization initiator is preferably a persulfate, an organic peroxide, or a mixture thereof, and more preferably ammonium persulfate or disuccinic acid peroxide.

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

In the polymerization step, it is preferable that the polymerization temperature is 30 to 100 ℃ and the polymerization pressure is 0.5 to 5.0MPa, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in a carboxyl group).

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the above polymerization step, it is preferable that the carboxylic acid type hydrocarbon-containing surfactant is added to the aqueous medium at a polymerization temperature of 30 to 100 ℃ and a polymerization pressure of 0.5 to 5.0MPa, and before the start of the polymerization or when the concentration of the fluoropolymer particles formed in the aqueous medium is 0.36% by mass or less, and the carboxylic acid type hydrocarbon-containing surfactant does not contain a carbonyl group (excluding a carbonyl group in the carboxyl group).

The polymerization temperature is more preferably 40 ℃ or higher, still more preferably 50 ℃ or higher, and particularly preferably 60 ℃ or higher. Further, it is more preferably 95 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is more preferably 1.0MPa or more, still more preferably 1.2MPa or more, and particularly preferably 1.5MPa or more. Further, it is more preferably 4.5MPa or less, further preferably 4.0MPa or less, particularly preferably 3.5MPa or less, and particularly preferably 3.0MPa or less.

The carboxylic acid type hydrocarbon-containing surfactant is added more preferably at a concentration of 0.2% by mass or less of the fluoropolymer particles, still more preferably at a concentration of 0.1% by mass or less, and particularly preferably is added at the same time as the start of polymerization. The carboxylic acid type hydrocarbon-containing surfactant is more preferably a compound represented by the above formula (a).

In the polymerization step, the polymerization pressure is preferably 1.5MPa or more, and the polymerization initiator is preferably a radical polymerization initiator.

The polymerization pressure is 1.8MPa or more (more preferably 2.0MPa or more, and particularly preferably 2.3MPa or more).

The radical polymerization initiator is preferably a persulfate, an organic peroxide, or a mixture thereof, and more preferably ammonium persulfate or disuccinic acid peroxide.

In the polymerization step, a known chain transfer agent may be further added according to the purpose to adjust the polymerization rate and the molecular weight.

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 hydrogen, isopentane, methane, ethane, propane, methanol, ethanol, isopropanol, acetone, various 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 fluorine-containing monomer in an aqueous medium in the substantial absence of oxygen in the presence of a bromine compound or an iodine compound (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, wherein R is^aWith or without 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 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-diiodon-propane, CF ₂Br₂、BrCF₂CF₂Br、CF₃CFBrCF₂Br、CFClBr₂、BrCF₂CFClBr、CFBrClCFClBr、BrCF₂CF₂CF₂Br、BrCF₂CFBrOCF₃1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluoro-1-butene, 2-bromo-4-iodoperfluoro-1-butene, monoiodomonobromo substituents of benzene, diiodomonobromo substituents, and (2-iodoethyl) and (2-bromoethyl) substituents, and the like, which 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 to be used may be suitably selected depending on the molecular weight of the target polymer, the type of the chain transfer agent to be used, the type and amount of the initiator to be used, and the like, and is usually 1 to 50,000ppm, preferably 1 to 20,000ppm, based on the total amount of the fluorine-containing 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 method for producing a fluoropolymer may be a method for producing a fluoropolymer comprising the steps of: a step (I) for producing an aqueous dispersion of particles of the fluorine-containing polymer (A) by polymerizing the fluorine-containing monomer in an aqueous medium in the presence of the carboxylic acid type hydrocarbon-containing surfactant; and (II) a step of seed-polymerizing the fluorine-containing monomer onto the fluorine-containing polymer (A) particles in the aqueous dispersion of the fluorine-containing polymer (A) particles.

The aqueous dispersion of the fluoropolymer can be obtained by the above-mentioned polymerization step, and the fluoropolymer powder can be produced by precipitating the aqueous dispersion.

The production method of the present invention may further comprise a precipitation step of precipitating the aqueous fluoropolymer dispersion. As the precipitation method, a conventionally known method can be employed depending on the kind of the fluoropolymer. The production method of the present invention may further comprise a step of separating the aqueous medium from the wet fluoropolymer powder obtained in the precipitation step.

The production method of the present invention preferably further comprises a step of drying the fluoropolymer obtained in the polymerization step. The aqueous dispersion is precipitated to separate the fluoropolymer, and the wet powder thus obtained is dried by heating means such as hot air while keeping the wet powder in a state where the wet powder is hardly fluidized, preferably in a state where the wet powder is left to stand. For example, the drying can be performed in a drying furnace while circulating air at a high temperature.

The drying temperature is preferably 155 ℃ or higher, more preferably 160 ℃ or higher, and still more preferably 170 ℃ or higher, because impurities in the fluoropolymer can be further reduced. The upper limit of the drying temperature is not particularly limited as long as it is a temperature at which the fluoropolymer is not deteriorated, and may be, for example, 300 ℃ or lower.

In the above drying, the average particle diameter of the fluoropolymer is preferably 0.5 to 2000 μm because impurities can be further reduced. A more preferable lower limit is 1 μm, a more preferable upper limit is 1000 μm, and a further preferable upper limit is 800 μm.

The average particle diameter was measured by a laser diffraction particle size distribution measuring apparatus (manufactured by japan laser corporation) under a pressure of 0.1MPa for a measurement time of 3 seconds without using a cascade, and the average particle diameter was a particle diameter corresponding to 50% of the integral of the obtained particle size distribution.

In the case of high molecular weight PTFE, the average particle diameter is a value measured in accordance with JIS K6891.

The aqueous fluoropolymer dispersion obtained in the polymerization step contains substantially no compound represented by the following general formula (3) and preferably contains more than 20ppm of a compound represented by the following general formula (4) relative to the fluoropolymer.

General formula (3): (H- (CF)₂)₈-SO₃)_qM²

(in the formula, M²Is 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. q is 1 or 2. R¹¹The same or different, H or an organic group having 1 to 10 carbon atoms. )

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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. R¹¹The same or different, H or an organic group having 1 to 10 carbon atoms. )

The aqueous fluoropolymer dispersion obtained in the polymerization step is a so-called polymerization-completed aqueous dispersion.

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) may be 500ppb or less with respect to the fluoropolymer. The content of the compound represented by the general formula (3) is preferably 100ppb or less, more preferably 25ppb or less, further preferably 15ppb or less, and particularly preferably 10ppb or less with respect to the fluoropolymer. The lower limit is not particularly limited, and may be 0ppb or 1 ppb.

The content of the compound represented by the general formula (4) may be more than 20ppm, 50ppm or more, or 100ppm or more based on the fluoropolymer. Further, the concentration may be 10000ppm or less, 5000ppm or less, 3000ppm or less, or 1000ppm or less.

When the content of the compounds represented by the general formulae (3) and (4) is measured by the method described later, the limit of quantification is about 10 to 100ppb, but the limit of quantification can be lowered by concentration. The concentration can be repeated for a plurality of times.

The polymerization step is preferably a step including: a step (I) for obtaining particles containing polymerized units based on a fluorine-containing monomer; and a step (II) of polymerizing a fluorine-containing monomer in an aqueous medium containing the particles obtained in the step (I) to obtain a fluorine-containing polymer.

The particles obtained in the step (I) are polymerized in an aqueous medium containing the particles obtained in the step (I) as described above, whereby the number of particles of the fluoropolymer can be increased and the amount obtained can be increased.

When the polymerization step includes the step (II), the step (II) may be performed by directly using an aqueous dispersion containing the particles obtained in the step (I).

The step (II) may be performed by diluting or concentrating the aqueous dispersion containing the particles obtained in the step (I). The dilution or concentration may be carried out directly in the reactor, or may be carried out after recovering the aqueous dispersion containing the particles obtained in step (I) from the reactor. Therefore, the polymerization step may further include a step of recovering the aqueous dispersion containing the particles obtained in step (I) after step (I) and before step (II).

After step (I) and before step (II), the aqueous dispersion containing the particles obtained in step (I) may be subjected to a step of reducing the temperature to less than 50 ℃, less than 30 ℃ or less than 10 ℃.

When the step (I) and the step (II) are continuously performed, after the step (I), the stirring may be temporarily stopped, and then the stirring may be restarted, followed by the step (II).

In the case where the step (I) and the step (II) are continuously performed, after the step (I), the stirring may be stopped, the pressure in the reactor may be changed, the stirring may be restarted, and the step (II) may be performed thereafter.

In order to change the monomer composition ratio in the reactor, after the step (I), the pressure in the reactor may be depressurized to atmospheric pressure, and after the various monomers are charged into the reactor, the step (II) may be performed. After the step (I), the polymerization temperature may be changed, followed by the step (II).

When the polymerization step includes the step (II), a redox initiator is particularly preferably used in the step (I). By using a redox initiator, the particle number of the above particles can be increased.

When the steps (I) and (II) are continuously performed, the polymerization initiator of the step (II) is added after the feeding of the redox initiator is stopped in the step (I), and thus the continuous production is possible. Examples of the redox initiator include those exemplified in the above-mentioned polymerization step.

When the polymerization step includes the step (II), a radical polymerization initiator may be used in the step (I). By using a radical polymerization initiator, the particle number of the above particles can be increased.

When the steps (I) and (II) are continuously performed, the polymerization initiator of the step (II) is added after the feeding of the radical polymerization initiator is stopped in the step (I), and thus the continuous production is possible. Examples of the radical polymerization initiator include those exemplified in the above-mentioned polymerization step, and ammonium persulfate is preferable in the step (I). In the step (II), disuccinic acid peroxide is preferable. In the step (II), the radical polymerization initiator is preferably continuously or intermittently charged. When a radical polymerization initiator is used in the step (I), the fluoropolymer is preferably a melt-processable fluororesin, a low-molecular-weight PTFE, or a modified PTFE. More preferably FEP, PFA, low molecular weight PTFE, or modified PTFE, and still more preferably low molecular weight PTFE or modified PTFE.

When the polymerization step includes the step (II), the step (I) is preferably a step of obtaining an aqueous dispersion having a particle concentration of 20.0 mass% or less. The solid content concentration is more preferably 15.0% by mass or less, further preferably 10.0% by mass or less, further preferably 8.0% by mass or less, and particularly preferably 5.0% by mass or less. The solid content concentration is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, further preferably 0.5% by mass or more, further preferably 0.8% by mass or more, particularly preferably 1.0% by mass or more, and particularly preferably 1.5% by mass or more.

The above particles are particles containing polymerized units based on a fluorine-containing monomer. The particles may contain only polymerized units based on a fluorine-containing monomer, or may contain polymerized units based on a fluorine-containing monomer and polymerized units based on a non-fluorine-containing monomer. As the fluorine-containing monomer and the non-fluorine-containing monomer, the monomers described in the above-mentioned polymerization step can be suitably used. The pellets may have the same monomer composition ratio as the non-melt-processable fluororesin (I), the melt-processable fluororesin (II), and the fluororubber (III), which will be described later.

The average primary particle diameter of the particles obtained in the step (I) is preferably 300nm or less, more preferably 200nm or less, and still more preferably 150nm or less. The average primary particle diameter is preferably 0.1nm or more, more preferably 1.0nm or more, and still more preferably 3.0nm or more.

The average primary particle diameter can be measured by a dynamic light scattering method. The average primary particle size can be measured by dynamic light scattering under conditions of 25 ℃, 1.3328 for the refractive index of the solvent (water), 0.8878mPa · s for the viscosity of the solvent (water), and 70 times of accumulation, to prepare an aqueous fluoropolymer dispersion in which the fluoropolymer solid content concentration is adjusted to about 1.0 mass%. As the dynamic light scattering method, for example, ELSZ-1000S (manufactured by Otsuka electronics Co., Ltd.) can be used.

The step (II) is a step of polymerizing a fluorine-containing monomer in an aqueous medium containing the particles to obtain a fluorine-containing polymer. In the step (II), only the fluorine-containing monomer may be polymerized, or the fluorine-containing monomer and the non-fluorine-containing monomer may be polymerized. As the fluorine-containing monomer and the non-fluorine-containing monomer, the monomers described in the above-mentioned polymerization step can be suitably used.

The aqueous medium is a reaction medium for carrying out the polymerization and is a liquid containing water. 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.

The aqueous medium in the step (II) preferably contains an aqueous medium contained in the aqueous dispersion containing the particles obtained in the step (I). In addition to the aqueous medium contained in the aqueous dispersion containing the above particles, other aqueous media may also be added.

The polymerization temperature and polymerization pressure in the step (II) 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 preferably 10 to 150 ℃. 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 preferably 0.05 to 10 MPa. The polymerization pressure is more preferably 0.3MPa or more, still more preferably 0.5MPa or more, still more preferably 5.0MPa or less, still more preferably 3.0MPa or less.

In particular, from the viewpoint of increasing the yield, it is preferably 1.0MPa or more, more preferably 2.0MPa or more.

The step (II) may be performed in the presence or absence of a carboxylic acid type hydrocarbon-containing surfactant.

The step (II) is preferably a step of polymerizing a fluorine-containing monomer in an aqueous medium containing the particles in the presence of a carboxylic acid type hydrocarbon-containing surfactant.

In the step (II), the amount of the carboxylic acid type hydrocarbon-containing surfactant is preferably 0.0001 to 15% by mass relative to the aqueous medium. The lower limit is more preferably 0.001 mass%, and the upper limit is more preferably 1 mass%. If less than 0.0001 mass%, the dispersing power may be insufficient; if the amount exceeds 15 mass%, the effect commensurate with the amount added cannot be obtained. The amount of the carboxylic acid type hydrocarbon-containing surfactant added is appropriately determined depending on the kind of the monomer used, the molecular weight of the target fluoropolymer, and the like.

The carboxylic acid type hydrocarbon-containing 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.

The step (II) preferably includes a step of continuously adding a carboxylic acid type hydrocarbon-containing surfactant. The continuous addition of the carboxylic acid type hydrocarbon-containing surfactant means, for example, that the carboxylic acid type hydrocarbon-containing surfactant is not added all at once but is added over time or in portions. By including the above-mentioned continuous addition step, an aqueous dispersion having a smaller average primary particle size and more excellent stability can be obtained.

In the step (II), the amount of the carboxylic acid type hydrocarbon-containing surfactant at the start of polymerization is preferably 1ppb or more with respect to the aqueous medium. The amount of the carboxylic acid type hydrocarbon-containing surfactant at the start of polymerization is preferably 10ppb or more, more preferably 50ppb or more, further preferably 100ppb or more, and further more preferably 200ppb or more. The upper limit is not particularly limited, but is preferably 100000ppm, more preferably 50000ppm, for example. When the amount of the carboxylic acid type hydrocarbon-containing surfactant at the start of polymerization is in the above range, 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 further reduced.

In the step (II), the step of continuously adding the carboxylic acid type hydrocarbon-containing surfactant is preferably performed such that the addition of the carboxylic acid type hydrocarbon-containing surfactant to the aqueous medium is started when the concentration of the fluoropolymer formed in the aqueous medium is 10% by mass or less. The carboxylic acid type hydrocarbon-containing surfactant is more preferably added at the time when the concentration is 8.0% by mass or less, further preferably added at the time when the concentration is 5.0% by mass or less, further preferably added at the time when the concentration is 4.0% by mass or less, particularly preferably added at the time when the concentration is 3.0% by mass or less, particularly preferably added at the time when the concentration is 2.0% by mass or less, particularly preferably added at the time when the concentration is 1.5% by mass or less, particularly preferably added at the time when the concentration is 1.0% by mass or less. The addition is preferably started when the concentration is less than 0.60% by mass, more preferably 0.50% by mass or less, still more preferably 0.36% by mass or less, yet more preferably 0.30% by mass or less, particularly preferably 0.20% by mass or less, and particularly preferably 0.10% by mass or less. Further, it is preferable to start the addition at the same time as the start of the polymerization in the step (II). The concentration is a concentration based on the total of the aqueous medium and the fluoropolymer.

By including the above steps, an aqueous dispersion having a smaller average primary particle size and more excellent stability can be obtained. In addition, an aqueous dispersion having a smaller amount of non-precipitated polymer can be obtained. Further, the aspect ratio of the primary particles can be further reduced.

In the step of continuously adding the carboxylic acid type hydrocarbon-containing surfactant, the amount of the carboxylic acid type hydrocarbon-containing surfactant added is preferably 0.01 to 10% by mass with respect to 100% by mass of the aqueous medium. The lower limit is more preferably 0.05% by mass, the lower limit is still more preferably 0.1% by mass, the upper limit is still more preferably 5% by mass, and the upper limit is still more preferably 1% by mass.

When the polymerization step includes the step (II), the polymerization step preferably includes a step of subjecting the carboxylic acid type hydrocarbon-containing surfactant to the radical treatment or the oxidation treatment.

The step (II) can be performed, for example, by: the polymerization can be carried out by charging an aqueous dispersion containing the particles, a fluorine-containing monomer, an aqueous medium, a non-fluorine-containing monomer, a carboxylic acid type hydrocarbon-containing surfactant, and other additives as required into a polymerization reactor, stirring the contents of the reactor, maintaining the reactor at a predetermined polymerization temperature, and then adding a predetermined amount of a polymerization initiator to initiate the polymerization reaction. After the polymerization reaction is started, a monomer, a polymerization initiator, a chain transfer agent, the carboxylic acid type hydrocarbon-containing surfactant, and the like may be added thereto according to the purpose. The carboxylic acid type hydrocarbon-containing surfactant may be added after the polymerization reaction is started.

The polymerization initiator is not particularly limited as long as it can generate radicals in the above polymerization temperature range, and known oil-soluble and/or water-soluble polymerization initiators can be used. Further, the polymerization may be 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 is preferably used. The step (II) is preferably a step carried out in the presence of an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator. It is particularly preferable to use the above-mentioned oil-soluble peroxide or water-soluble peroxide as the polymerization initiator.

In the step (II), it is preferable to polymerize the fluorine-containing monomer in the substantial absence of the fluorine-containing surfactant. "substantially in the absence of a fluorinated surfactant" means that the fluorinated surfactant is 1ppm or less, preferably 100ppb or less, more preferably 10ppb or less, and still more preferably 1ppb or less, relative to the fluoropolymer obtained in the polymerization.

The polymerization in the step (I) or the step (II) may be further carried out in the presence of a nucleating agent. The nucleating agent may be used only in the step (I), only in the step (II), or both the step (I) and the step (II).

Examples of the fluoropolymer suitably produced by the production method of the present invention 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. Hereinafter, more preferred embodiments are described for each fluoropolymer.

The TFE polymer may be suitably a TFE homopolymer, or 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 fluoro (alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; fluoro dioxole; a perfluoroalkylethylene; omega-hydrogenated perfluoroolefins; and so on.

The TFE polymer may be a copolymer of TFE and 1 or 2 or more kinds 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 suitably be a VDF homopolymer [ PVDF ], or a copolymer composed of: (1) VDF; (2) 1 or 2 or more fluoroolefins other than VDF 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; and so on.

The CTFE polymer may be suitably a CTFE homopolymer, or a copolymer composed of: (1) CTFE; (2) 1 or 2 or more fluoroolefins other than 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 produced by the production method of the present invention may be glassy, plastic or elastomeric. These materials are amorphous or partially crystalline and can be subjected to compression firing processing, melt processing or non-melt processing.

The following substances can be suitably produced by the production method of the present invention, for example: (I) tetrafluoroethylene polymer [ TFE Polymer (PTFE) ] as a non-melt-processable fluororesin, (II) ethylene/TFE copolymer [ ETFE ], TFE/HFP copolymer [ FEP ], TFE/perfluoro (alkyl vinyl ether) copolymer [ PFA, MFA, etc. ], TFE/VDF copolymer, electrolyte polymer precursor as a melt-processable fluororesin, (III) TFE/propylene copolymer, TFE/propylene/3 rd monomer copolymer (the 3 rd monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ethers, etc.), 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; and so on.

The fluorine-containing polymer 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%, still more preferably a fluororesin having a fluorine substitution rate of 55% or more, still more preferably a fluororesin having a fluorine substitution rate of 60% or more, still further 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 perfluororesin that is a fluororesin having a fluorine substitution rate of 90 to 100%.

(formula (II))

The fluorine substitution rate (%)/((the number of hydrogen atoms bonded to carbon atoms constituting the fluoropolymer) + (the 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 particularly preferably high molecular weight PTFE.

The fluoropolymer may have a core-shell structure. Examples of the fluoropolymer having a core-shell structure include modified PTFE in which particles contain a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE. Examples of such modified PTFE include PTFE described in JP-A-2005-527652.

As the core-shell structure, the following structure can be adopted.

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, even 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 mass%, more preferably 99.0 mass%, still more preferably 98.0 mass%, even more preferably 97.0 mass%, particularly preferably 95.0 mass%, most preferably 90.0 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 (the 3-layer structure has a core center portion of modified PTFE, a core outer layer portion of TFE homopolymer, and a shell of modified PTFE). Examples of the fluoropolymer having a 3-layer structure include PTFE described in international publication No. 2006/054612.

The above-mentioned (I) non-melt-processable fluororesin, (II) melt-processable fluororesin and (III) fluororubber suitably produced by the production method of the present invention are preferably produced as follows.

(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 amount of the fluoropolymer to be obtained, 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, the polymerization is initiated by charging pure water into a pressure-resistant reaction vessel equipped with a stirrer, deoxidizing, charging TFE to a predetermined temperature, and adding a polymerization initiator. 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, TFE in the reaction vessel was purged, and the temperature was returned 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.

The modifying monomer is not particularly limited as long as it can be copolymerized with TFE, and examples thereof include: perfluoroolefins such as hexafluoropropylene [ HFP ]; chlorofluoroalkenes such as chlorotrifluoroethylene [ CTFE ]; hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride [ VDF ]; a perfluorovinyl ether; a perfluoroalkylethylene; ethylene; fluorine-containing vinyl ethers having a nitrile group, and the like. The number of the modifying monomers used may be 1, or 2 or more.

The perfluorovinyl ether is not particularly limited, and examples thereof include those represented by the following general formula (X)

CF₂＝CF-ORf(X)

And (wherein Rf represents a perfluoroorganic group). 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 aforementioned perfluoroorganic group may have an ether oxygen.

Examples of the perfluorovinyl ether include perfluoro (alkyl vinyl ether) [ PAVE ] in which Rf in the general formula (X) 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 the PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group, and a perfluoromethyl vinyl ether [ PMVE ] in which the perfluoroalkyl group is a perfluoromethyl group and a perfluoropropyl vinyl ether [ PPVE ] in which the perfluoroalkyl group is a perfluoropropyl group are preferable.

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

The modified monomer in the modified PTFE is preferably at least one selected from the group consisting of HFP, CTFE, VDF, PMVE, PPVE, PFBE, PFHE, and ethylene.

In the modified PTFE, the modified monomer unit is preferably in the range of 0.00001 to 1 mass%. The lower limit of the modifying monomer unit is more preferably 0.0001% by mass, still more preferably 0.001% by mass, and yet more preferably 0.01% by mass. The upper limit of the modified monomer unit is more preferably 0.5% by mass, and still more preferably 0.3% by mass. In the present specification, the modified monomer unit refers to a portion derived from a modified monomer that is a part of the molecular structure of the modified PTFE, and the total monomer unit refers to a portion derived from a total monomer in the molecular structure of the modified PTFE.

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

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

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 0.78MPa and a temperature of 70 ℃. 0.05g, 0.1g, 0.2g, 0.5g and 1.0g of a comonomer were fed into the reactor, respectively, and 0.072g of ammonium persulfate (20 ppm relative to water) was fed thereto, and TFE was continuously fed so as to maintain a polymerization pressure of 0.78 MPa. After 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 precipitate a 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 comonomer (3) having a monomer reactivity ratio of 0.1 to 8 is preferably at least one selected from the group consisting of comonomers represented by formulae (3a) to (3 d).

CH₂＝CH-Rf¹(3a)

(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 66]

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

[ solution 67]

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

The content of the comonomer (3) is preferably in the range of 0.00001 to 1.0 mass% with respect to the modified PTFE. The lower limit is more preferably 0.0001% by mass, still more preferably 0.001% by mass, yet more preferably 0.005% by mass, and particularly preferably 0.009% by mass. The upper limit is more preferably 0.50% by mass, still more preferably 0.40% by mass, yet more preferably 0.30% by mass, particularly preferably 0.10% by mass, and particularly preferably 0.05% by mass.

The modified monomer is preferably at least one selected from the group consisting of hexafluoropropylene, vinylidene fluoride, fluoro (alkyl vinyl ether), (perfluoroalkyl) ethylene, and a modified monomer having a functional group capable of undergoing a radical polymerization reaction and a hydrophilic group, because an aqueous dispersion having a small average primary particle diameter, a small aspect ratio, and excellent stability of polytetrafluoroethylene particles can be obtained.

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

More preferably, at least one 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 in the range of 0.00001 to 1.0 mass% relative to the modified PTFE. The lower limit of the total amount is more preferably 0.001 mass%, still more preferably 0.005 mass%, and particularly preferably 0.009 mass%. The upper limit is more preferably 0.50% by mass, still more preferably 0.40% by mass, yet more preferably 0.30% by mass, particularly preferably 0.10% by mass, and particularly preferably 0.05% by mass.

In the production method of the present invention, a modifying monomer (hereinafter referred to as "modifying monomer (a)") having a functional group capable of reacting by radical polymerization and a hydrophilic group may be used together with the surfactant. The modifying monomer (a) may be a compound having a surface-active ability and containing at least 1 or more vinyl groups. Examples of the hydrophilic group in the modified monomer (A) include-NH ₂、-PO₃M、-OPO₃M、-SO₃M、-OSO₃M and-COOM (in the formula, M is H, metal atom, NR)⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Are H or an organic group, which may be the same or different. Any 2 of which may be bonded to each other to form a ring). As the above hydrophilic group, -SO is preferable₃M 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.

Examples of the "functional group capable of undergoing radical polymerization" in the modified monomer (a) include groups having an ethylenically unsaturated bond. Examples of the group having an ethylenically unsaturated bond 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.

The modifying monomer (A) is preferably of the general formula (4):

CXⁱX^k＝CX^jR^a-(CZ¹Z²)_k-Y³(4)

(in the formula, Xⁱ、X^jAnd X^kEach 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 CF ₃And k is 0 or 1).

Examples of the hydrophilic group include-NH₂、-PO₃M、-OPO₃M、-SO₃M、-OSO₃M and-COOM (in the formula, M is H, metal atom, NR)⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Are H or an organic group, which may be the same or different. Any 2 of which may be bonded to each other to form a ring). As the above hydrophilic group, -SO is preferable₃M 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 further reduced.

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 The upper limit may be 10 or more, or 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 structure, a cyclic or acyclic structure, a saturated or unsaturated structure, a substituted or unsubstituted structure, and may contain 1 or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen, and may contain 1 or more functional groups selected from the group consisting of esters, amides, sulfonamides, carbonyls, carbonates, carbamates, ureas, and carbamates, if desired. The linking group does not contain a carbon atom, and may be a chain hetero atom such as oxygen, sulfur or nitrogen.

R is as defined above^aPreferred is a chain hetero atom such as oxygen, sulfur, and nitrogen, or a 2-valent organic group.

R^aIn the case of a 2-valent organic group, a hydrogen atom bonded to a carbon atom may be replaced 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 non-fluorinated 2-valent organic group, or may be a partially fluorinated or perfluorinated 2-valent organic group.

As R^aThis may be, for example: a hydrocarbon group having no fluorine atom bonded to a carbon atom; a hydrocarbon group in which a part of hydrogen atoms bonded to carbon atoms is substituted with a fluorine atom; a hydrocarbon group in which all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms; the hydrocarbon group containing- (C ═ O) -, - (C ═ O) -O-or- (C ═ O) -, may contain an oxygen atom, may contain a double bond, and may contain a functional group.

R^aThe hydrocarbon group may preferably contain a carbon number of 1 to 100, optionally a carbonyl group, and optionally an ether bond, and may contain fluorine in part or all of the hydrogen atoms bonded to the carbon atoms.

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 independently may be 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^aA preferable specific example thereof is-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, specifically, R is as defined above^apreferably-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 above formula, n is an integer of 1 to 10.

as-R in the above general formula (4)^a-(CZ¹Z²)_kpreferably-CF ₂-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 above formula, n is an integer of 1 to 10.

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

[ solution 68]

(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 also preferable:

-(C＝O)_h-(O)_i-CF₂-O-(CX⁷ ₂)_e-(O)_g- (r2)

(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, and i is a 2-valent group represented by 0 or 1).

In addition, as the above-mentioned-R of the general formula (4)^a-CZ¹Z²The following formula (t1) is also preferred:

-(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 shown in the formula (t1), Z¹And Z²More preferably, one is F and the other is CF₃。

In the above general formula (4), the group represented by the formula-R^a-CZ¹Z²The following formula (t2) is also preferred:

-(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, Z ¹And Z²Each independently H, F or CF₃) The 2-valent group shown in the formula (t2), Z¹And Z²More preferably, one is F and the other is CF₃。

The compound represented by the formula (4) is also preferably selected in addition to the hydrophilic group (Y)³) And has no C-H bond and a C-F bond. That is, in the general formula (4), X is preferableⁱ、X^jAnd X^kAll are F, R^aThe perfluoroalkylene group may be any of a chain and a branched chain, may be any of a cyclic and an acyclic, and may contain at least 1 chain hetero atom. The number of carbon atoms of the perfluoroalkylene group may be 2 to 20, or 4 to 18.

The compounds of formula (4) may also be partially fluorinated. That is, the compound represented by the general formula (4) is also preferably selected from hydrophilic groups (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 (4) is also preferably a compound represented by the following formula (4 a).

CF₂＝CF-O-Rf⁰-Y³(4a)

(in the formula, Y³Is a hydrophilic group, Rf⁰The perfluorinated compound is a perfluorinated divalent linking group which is perfluorinated, may have a chain or branched chain structure, a cyclic or acyclic structure, a saturated or unsaturated structure, a substituted or unsubstituted structure, 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 (4) is also preferably a compound represented by the following formula (4 b).

CH₂＝CH-O-Rf⁰-Y³(4b)

(in the formula, Y³Is a hydrophilic group, Rf⁰A per-fluorinated divalent linking group as defined for formula (4 a). )

In the general formula (4), Y³is-OSO₃M is one of the preferred modes. At Y³is-OSO₃In the case of M, - [ CF ] is mentioned as a polymerization unit based on the compound represented by the general formula (4)₂CF(OCF₂CF₂CH₂OSO₃M)]-、-[CH₂CH((CF₂)₄CH₂OSO₃M)]-、-[CF₂CF(O(CF₂)₄CH₂OSO₃M)]-、-[CF₂CF(OCF₂CF(CF₃)CH₂OSO₃M)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂CH₂OSO₃M)]-、-[CH₂CH((CF₂)₄CH₂OSO₃M)]-、-[CF₂CF(OCF₂CF₂SO₂N(CH₃)CH₂CH₂OSO₃M)]-、-[CH₂CH(CF₂CF₂CH₂OSO₃M)]-、-[CF₂CF(OCF₂CF₂CF₂CF₂SO₂N(CH₃)CH₂CH₂OSO₃M)]-、-[CH₂CH(CF₂CF₂CH₂OSO₃M)]-and the like. In the above formula, M is the same as described above.

In the general formula (4), Y³is-SO₃M is also one of the preferred modes. At Y³is-SO₃In the case of M, - [ CF ] is mentioned as a polymerization unit based on the compound represented by the general formula (4)₂CF(OCF₂CF₂SO₃M)]-、-[CF₂CF(O(CF₂)₄SO₃M)]-、-[CF₂CF(OCF₂CF(CF₃)SO₃M)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂SO₃M)]-、-[CH₂CH(CF₂CF₂SO₃M)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂CF₂CF₂SO₃M)]-、-[CH₂CH((CF₂)₄SO₃M)]-、-[CH₂CH(CF₂CF₂SO₃M)]-、-[CH₂CH((CF₂)₄SO₃M)]-and the like. In the above formula, M is the same as described above.

In the general formula (4), Y³It is also one of the preferred modes to be-COOM. At Y³In the case of-COOM, - [ CF ] is mentioned as a polymerization unit based on the compound represented by the general formula (4)₂CF(OCF₂CF₂COOM)]-、-[CF₂CF(O(CF₂)₅COOM)]-、-[CF₂CF(OCF₂CF(CF₃)COOM)]-、-[CF₂CF(OCF₂CF(CF₃)O(CF₂)_nCOOM)]- (n greater than 1), [ CH₂CH(CF₂CF₂COOM)]-、-[CH₂CH((CF₂)₄COOM)]-、-[CH₂CH(CF₂CF₂COOM)]-、-[CH₂CH((CF₂)₄COOM)]-、-[CF₂CF(OCF₂CF₂SO₂NR’CH₂COOM)]-、-[CF₂CF(O(CF₂)₄SO₂NR’CH₂COOM)]-、-[CF₂CF(OCF₂CF(CF₃)SO₂NR’CH₂COOM)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂SO₂NR’CH₂COOM)]-、-[CH₂CH(CF₂CF₂SO₂NR’CH₂COOM)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂CF₂CF₂SO₂NR’CH₂COOM)]-、-[CH₂CH((CF₂)₄SO₂NR’CH₂COOM)]-、-[CH₂CH(CF₂CF₂SO₂NR’CH₂COOM)]-、-[CH₂CH((CF₂)₄SO₂NR’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 (4), Y³is-OPO₃M is also one of the preferred modes. At Y³is-OPO₃In the case of M, - [ CF ] is mentioned as a polymerization unit based on the compound represented by the general formula (4)₂CF(OCF₂CF₂CH₂OP(O)(OM)₂)]-、-[CF₂CF(O(CF₂)₄CH₂OP(O)(OM)₂)]-、-[CF₂CF(OCF₂CF(CF₃)CH₂OP(O)(OM)₂)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂CH₂OP(O)(OM)₂)]-、-[CF₂CF(OCF₂CF₂SO₂N(CH₃)CH₂CH₂OP(O)(OM)₂)]-、-[CF₂CF(OCF₂CF₂CF₂CF₂SO₂N(CH₃)CH₂CH₂OP(O)(OM)₂)]-、-[CH₂CH(CF₂CF₂CH₂OP(O)(OM)₂)]-、-[CH₂CH((CF₂)₄CH₂OP(O)(OM)₂)]-、-[CH₂CH(CF₂CF₂CH₂OP(O)(OM)₂)]-、-[CH₂CH((CF₂)₄CH₂OP(O)(OM)₂)]-and the like. In the above formula, M is the same as described above.

In the general formula (4), Y³is-PO₃M is also one of the preferred modes. At Y ³is-PO₃In the case of M, - [ CF ] is mentioned as a polymerization unit based on the compound represented by the general formula (4)₂CF(OCF₂CF₂P(O)(OM)₂)]-、-[CF₂CF(O(CF₂)₄P(O)(OM)₂)]-、-[CF₂CF(OCF₂CF(CF₃)P(O)(OM)₂)]-、-[CF₂CF(OCF₂CF(CF₃)OCF₂CF₂P(O)(OM)₂)]-、-[CH₂CH(CF₂CF₂P(O)(OM)₂)]-、-[CH₂CH((CF₂)₄P(O)(OM)₂)]-、-[CH₂CH(CF₂CF₂P(O)(OM)₂)]-and- [ CH₂CH((CF₂)₄P(O)(OM)₂)]Wherein M is the same as described above.

The compound represented by the above general formula (4) is preferably at least one selected from the group consisting of the following monomers, the monomers being represented by the following general formula (5):

CX₂＝CY(-CZ₂-O-Rf-Y³) (5)

(wherein X is the same or different and is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, and Z is the same or different and is-H, -F, alkylOr a fluoroalkyl group. Rf is a C1-40 fluoroalkylene group or a C2-100 fluoroalkylene group having an ether bond. Y is³The same as described above). ) A monomer as shown; the following general formula (6):

CX₂＝CY(-O-Rf-Y³) (6)

(wherein X is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, and Rf is a C1-40 fluoroalkylene group or a C2-100 fluoroalkylene group having an ether bond.) Y³The same as above); and the following general formula (7):

CX₂＝CY(-Rf-Y³) (7)

(wherein X is-H or-F, Y is-H, -F, alkyl or fluoroalkyl, and Rf is a C1-40 fluoroalkylene group or a C2-100 fluoroalkylene group having an ether bond.) Y ³The same as described above).

The fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms is an alkylene group having an ether bond between carbon and carbon atoms, and having a structure in which an oxygen atom is not contained as a terminal.

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

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

The alkyl group may be an alkyl group containing no fluorine atom and having 1 or more carbon atoms. 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 be an alkyl group containing at least 1 fluorine atom and having 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 (5), Z, which may be the same or different, is-H, -F, alkyl or fluoroalkyl.

The alkyl group may be an alkyl group containing no fluorine atom and having 1 or more carbon atoms. 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 be an alkyl group containing at least 1 fluorine atom and having 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 above general formula (5), at least 1 of X, Y and Z preferably contains a fluorine atom. For example, X may be-H, and Y and Z may be-F.

In the general formula (5), 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 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.

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

For example, the following formula is also preferred:

[ solution 69]

(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, wherein, in Z ³And Z⁴P1+ q1+ r1+ s1 are not all H) 2-valent groups.

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-、-CF(CF₃)CH₂-and the like.

The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

In the above general formula (5), Y³is-COOM, -SO₃M or-OSO₃M (M is H, a metal atom, NR)⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Are H or an organic group, which may be the same or different. Any 2 may be bonded to each other to form a ring. ).

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 preferred is-Na, -K or-NH₄Particularly preferred is-Na or-NH₄Most preferably-NH ₄。

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

Examples of the monomer represented by the general formula (5) include the following formula (5 a):

CX^h ₂＝CFCF₂-O-(CF(CF₃)CF₂O)_n5-CF(CF₃)-Y³(5a)

(in the formula, each X^hThe same indicates F or H. n5 represents 0 or an integer of 1 to 10, Y³The same as defined above) as a preferred substance.

In the general formula (5a), n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and still more preferably 0 or 1, from the viewpoint of obtaining PTFE particles having a small primary particle diameter. From the viewpoint of obtaining appropriate water solubility and surface activity, Y is³preferably-COOM, and M is preferably H or NH, from the viewpoint of being less likely to remain as an impurity and improving the heat resistance of the obtained composition and the drawn body obtained from the composition₄。

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

CH₂＝CF(-CF₂-O-Rf-Y³) (5b)

(wherein Rf and Y³As described above. )

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

[ solution 70]

(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; t1Is an integer of 0 to 5, Y³As described above. Wherein Z is³And Z⁴P1+ q1+ r1+ s1 is not 0) in all cases. More specifically, preferred examples thereof include

[ solution 71]

CH₂＝CFCF₂OCH₂CF₂-Y³，CH₂＝CFCF₂O(CH₂CF₂CF₂O)CH₂CF₂-Y³，

CH₂＝CFCF₂OCH₂CF₂CH₂-Y³，

CH₂＝CFCF₂O(CH₂CF₂CF₂O)CH₂CF₂CH₂-Y³，

CH₂＝CFCF₂OCF₂CF₂-Y³，CH₂＝CFCF₂O(CF₂CF₂CF₂O)CF₂CF₂-Y³，

CH₂＝CFCF₂OCF₂CF₂CH₂-Y³，

CH₂＝CFCF₂O(CF₂CF₂CF₂O)CF₂CF₂CH₂-Y³，

CH₂＝CFCF₂OCF₂-Y³，CH₂＝CFCF₂O(CF₂CF₂O)CF₂-Y³，

CH₂＝CFCF₂OCF₂CH₂-Y³，

CH₂＝CFCF₂O(CF₂CF₂O)CF₂CH₂-Y³，

Etc., among them, preferred are

[ chemical formula 72]

As the monomer represented by the above general formula (5b), Y in the formula (5b) is preferable³is-COOM, particularly preferably selected from the group consisting of CH₂＝CFCF₂OCF(CF₃) COOM and CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃) COOM (wherein M is as defined above), more preferably CH₂＝CFCF₂OCF(CF₃)COOM。

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

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

(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 (5c), 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. The above Y is a group of compounds having a suitable water solubility and stability of the aqueous dispersion³preferably-COOM¹In view of the difficulty of remaining as impurities and the improvement in heat resistance of the molded article obtained, the above M is used¹Preferably H or NH₄。

Examples of the perfluorovinyl alkyl compound represented by the formula (5c) include CH₂＝CFCF₂OCF(CF₃)COOM¹、CH₂＝CFCF₂OCF(CF₃)CF₂OCF(CF₃)COOM¹(in the formula, M¹Same as defined above).

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

CF₂＝CFCF₂-O-Rf-Y³(5d)

(wherein Rf and Y³As described above. )

More specifically, there may be mentioned

[ solution 73]

CF₂＝CFCF₂OCF₂CF₂CF₂-Y³，

CF₂＝CFCF₂OCF₂CF₂CF₂CH₂-Y³,

And the like.

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

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

The alkyl group may be an alkyl group containing no fluorine atom and having 1 or more carbon atoms. 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 be an alkyl group containing at least 1 fluorine atom and having 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 (6), at least 1 of the X and Y preferably contains a fluorine atom. For example, X may be-H, and Y and Z may be-F.

In the general formula (6), 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. Preferably 30 or less, more preferably 20 or less The lower, 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.

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

CF₂＝CF-O-(CF₂)_n1-Y³(6a)

(wherein n1 represents an integer of 1 to 10, and Y represents³represents-SO₃M¹or-COOM¹，M¹Represents H, a metal atom, NR⁷ ₄Imidazolium with or without substituents, pyridinium with or without substituents or phosphonium with or without substituents, R⁷Represents H or an organic group. )

CF₂＝CF-O-(CF₂C(CF₃)F)_n2-Y³(6b)

(wherein n2 represents an integer of 1 to 5, and Y represents³As 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-CF₂CF₂-Y³(6d)

(wherein n4 represents an integer of 1 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. The above Y is a group of compounds having a suitable water solubility and stability of the aqueous dispersion³preferably-COOM¹From difficulty to difficultyM is a residual impurity to improve the heat resistance of the resulting molded article¹Preferably H or NH₄。

Examples of the perfluorovinyl alkyl compound represented by the formula (6a) include CF ₂＝CF-O-CF₂COOM¹(in the formula, M¹Same as defined above).

In the above formula (6b), n2 is preferably an integer of 3 or less from the viewpoint of stability of the aqueous dispersion to be obtained, and Y is an integer of appropriate water solubility and stability of the aqueous dispersion to be obtained³preferably-COOM¹M is difficult to remain as impurities and improves the heat resistance of the resulting molded article¹Preferably H or NH₄。

In the formula (6c), n3 is preferably an integer of 5 or less from the viewpoint of water solubility, and Y is preferably an integer of 5 or less from the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion³preferably-COOM¹From the viewpoint of improving dispersion stability, M is¹Preferably H or NH₄。

In the above formula (6d), the X is a group represented by the formula¹preferably-CF₃In terms of water solubility, n4 is preferably an integer of 5 or less, and Y is an integer of 5 or less in terms of obtaining appropriate water solubility and stability of the aqueous dispersion³preferably-COOM¹M above¹Preferably H or NH₄。

Examples of the perfluorovinyl ether compound represented by the formula (6d) include CF₂＝CFOCF₂CF(CF₃)OCF₂CF₂COOM¹(in the formula, M¹Representation H, NH₄Or an alkali metal).

In the general formula (7), Rf is preferably a C1-40 fluoroalkylene group. In the general formula (7), at least one of X and Y preferably contains a fluorine atom.

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

CF₂＝CF-(CF₂)_n1-Y³(7a)

(wherein n1 represents an integer of 1 to 10, and Y represents³The same as defined above), and 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 represents³Same as defined above) of the above-mentioned monomers.

Y is above³preferably-SO₃M¹or-COOM¹，M¹Preferably H, a metal atom, NR⁷ ₄An imidazolium with or without substituents, a pyridinium with or without substituents or a phosphonium with or without substituents. 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. The above Y is a group of compounds having a suitable water solubility and stability of the aqueous dispersion³preferably-COOM¹M is difficult to remain as impurities and improves the heat resistance of the resulting molded article¹Preferably H or NH₄。

Examples of the perfluorovinyl alkyl compound represented by the formula (7a) include CF₂＝CFCF₂COOM¹(in the formula, M¹Same as defined above).

In the above formula (7b), n2 is preferably an integer of 3 or less from the viewpoint of stability of the aqueous dispersion to be obtained, and Y is an integer of appropriate water solubility and stability of the aqueous dispersion to be obtained ³preferably-COOM¹M is difficult to remain as impurities and improves the heat resistance of the resulting molded article¹Preferably H or NH₄。

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, yet more preferably 0.005% by mass, and particularly preferably 0.009% by mass. The upper limit is preferably 0.90% by mass, more preferably 0.50% by mass, still more preferably 0.40% by mass, yet more preferably 0.30% by mass, particularly preferably 0.10% by mass, and particularly preferably 0.05% by mass.

In the above TFE Polymer (PTFE), the Standard Specific Gravity (SSG) and the Melt Viscosity (MV) used as indices of molecular weight are not particularly limited.

In the production of the TFE polymer, the carboxylic acid type hydrocarbon-containing surfactant can be used in the range of use in the production method of the present invention. The concentration of the 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 is large, needle-like particles having a large aspect ratio are formed, and the aqueous dispersion is in the form of a gel and the stability is impaired.

The lower limit of the amount of the carboxylic acid type hydrocarbon-containing surfactant to be used is preferably 0.0001% by mass, more preferably 0.001% by mass, still 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 surfactant to be used is preferably 10 mass%, more preferably 5 mass%, still more preferably 3 mass%, and particularly preferably 2 mass% with respect to the aqueous medium.

The carboxylic acid type hydrocarbon-containing 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 above-mentioned TFE polymer, a persulfate, an organic peroxide, or a mixture thereof may be used as a radical polymerization initiator. Examples of the persulfate include ammonium persulfate and potassium persulfate. Examples of the organic peroxide include disuccinic acid peroxide and dipentanedioic acid peroxide.

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 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, manganese triacetate/oxalic acid, cerium ammonium nitrate/oxalic acid, etc., 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 above-mentioned TFE polymer, known chain transfer agents can be used, 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 and ethanol, hydrogen, and the like, and preferably a substance in a gas 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. The amount of the above-mentioned compound may be 1 to 1000ppm, or 1 to 500 ppm.

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 further used as a dispersion stabilizer in 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 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 surfactant and a fluoropolymer. By using the above surfactant, an aqueous dispersion of particles of TFE polymer having a fine particle diameter of 0.5 μm or less can be obtained.

The aqueous dispersion can be precipitated to produce a fine powder. The aqueous dispersion of the above-mentioned TFE polymer can be used in various applications as a fine powder by precipitation, washing and drying. In the case of precipitating the aqueous dispersion of the TFE polymer, an aqueous dispersion obtained by polymerization such as a polymer emulsion is usually diluted with water to a polymer concentration of 10 to 20 mass%, and in some cases, after adjusting the pH to be neutral or alkaline, the aqueous dispersion is stirred in a vessel with a stirrer more vigorously than the stirring during the reaction. In the precipitation, a 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 precipitating agent and stirred at the same time. The precipitation may be continuously performed by using a line mixer or the like.

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

Before or during the above precipitation, a pigment or a filler-containing TFE polymer fine powder in which a pigment or a filler is uniformly mixed can be obtained by adding a pigment for coloring or various fillers for improving mechanical properties.

The wet powder obtained by precipitating the aqueous dispersion of the TFE polymer is usually dried by vacuum, high frequency, hot air, or the like 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 that they simply fibrillate even if subjected to a small shearing force, losing the state of the original stable particle structure.

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 applications for flexible hoses and wire coating of reagents, steam, and the like.

The aqueous dispersion of TFE polymer obtained by the above polymerization is preferably stabilized by adding a nonionic surfactant, further concentrated, and added with an organic or inorganic filler according to the purpose to prepare a composition for various uses. 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 device or the like, impregnation processing of a glass cloth, or the like.

Organosols of TFE polymers can also be prepared from the aqueous dispersions described above. 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 used as appropriate. The preparation of the organosol can be carried out, for example, by the method described in International publication No. 2012/002038.

The aqueous dispersion of the above-mentioned TFE polymer or the above-mentioned fine powder of TFE polymer is also preferably used as a processing aid. When the aqueous dispersion or the fine powder is used as a processing aid, the melt strength of the host polymer during melt processing can be improved by mixing the aqueous dispersion or the fine powder with the host polymer, and the mechanical strength, electrical characteristics, flame retardancy, dripping resistance during burning, and sliding properties of the obtained polymer can be improved.

The aqueous dispersion of the above TFE polymer or the above fine powder of TFE polymer is also preferably used as a battery binder 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 not inferior to the processing aids described in the above publications.

The aqueous dispersion of TFE polymer is preferably mixed with an aqueous dispersion of melt-processable fluororesin and precipitated to form a co-precipitated powder. The above-mentioned coprecipitated powder is suitable as a processing aid.

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

The aqueous dispersion preferably further contains the melt-processable fluororesin. Examples of the melt-processable fluororesin include FEP, PFA, ETFE, EFEP, and the like. The aqueous dispersion 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 non-fluorine-containing resin to which the above-mentioned co-precipitation 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 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, Japanese patent No. 2538783 and the like.

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 hazardous substance leveling, explosion-proof, cosmetics, pet litter such as cat litter, and the like.

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 TFE polymer fiber is obtained by mixing the aqueous dispersion of the TFE polymer with the aqueous dispersion of the matrix polymer, extruding the mixture to form an intermediate fiber structure, and firing the intermediate fiber structure to decompose the matrix polymer and sinter the TFE polymer particles.

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 surfactant, PTFE having a molecular weight equivalent to that in the production method using the conventional fluorosurfactant can be surprisingly produced without using the conventional fluorosurfactant.

In the case of producing high molecular weight PTFE, the polymerization temperature is preferably 30 ℃ or higher, more preferably 40 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is preferably 100 ℃ or lower, more preferably 95 ℃ or lower. The polymerization pressure is preferably 0.5MPa or more, preferably 0.7MPa or more, preferably 1.0MPa or more, and further preferably 5.0MPa or less, more preferably 4.0MPa or less, and further preferably 3.0MPa or less.

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.

Further, a biaxially stretched film can be obtained by 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, and 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.

Specific applications are exemplified below.

Field of electrochemistry

Dielectric prepreg, EMI shielding material, heat transfer material, and the like. More specifically, 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 semiconductor liquid filtration filter (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.

General field of consumable materials

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

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 augmentation materials), head and neck articles (dura mater substitutes), oral health (tissue regeneration medicine), plastic surgery (taping), and the like.

Low molecular weight PTFE can also be produced using the surfactants described above.

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

In the case of producing low molecular weight PTFE, the polymerization temperature is preferably 30 ℃ or higher, more preferably 40 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is preferably 100 ℃ or lower, more preferably 90 ℃ or lower, and still more preferably 80 ℃ or lower. The polymerization pressure is preferably 0.3MPa or more, preferably 0.4MPa or more, preferably 0.5MPa or more, more preferably 5.0MPa or less, more preferably 4.0MPa or less, and still more preferably 3.0MPa or less.

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 dispersing a polymerization initiator and the above surfactant in an aqueous medium in the presence of a chain transfer agent to polymerize TFE or a monomer copolymerizable with TFE, and TFE.

When the low molecular weight PTFE obtained by the polymerization is used as a powder, the powder particles can be prepared by precipitating the aqueous dispersion.

In the present invention, high molecular weight PTFE means PTFE having non-melt processability and fibrillating properties. The low molecular weight PTFE means PTFE having melt processability and no fibrillation.

The non-melt processability means that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point according to ASTM D-1238.

The presence or absence of fibrillation can be judged by "paste extrusion", which is a typical method for molding "high molecular weight PTFE powder" that is powder made of a polymer of TFE. This is because, in general, high molecular weight PTFE has fibrillating properties when paste extrusion is possible. When a continuous extrudate (extruded strand) is not obtained by paste extrusion or an unfired molded product obtained by paste extrusion does not have substantial strength or elongation, for example, when the elongation is 0% and the molded product is broken by stretching, it is considered that the molded product does not have fibrillation.

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 underwater substitution method according to ASTM D-792 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 melt viscosity of 1X 10 at 380 deg.C²～7×10⁵Pa · s. In the present invention, "low molecular weight" means that the melt viscosity is in the above range.

The melt viscosity of the high molecular weight PTFE is significantly higher than that of the low molecular weight PTFE, and it is difficult to measure the exact melt viscosity. On the other hand, the melt viscosity of the low molecular weight PTFE can be measured, but it is difficult to obtain a molded article useful for measuring the standard specific gravity from the low molecular weight PTFE, and it is difficult to measure the 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 melt viscosity is used as an index of the molecular weight of the low molecular weight PTFE. In addition, no method is known for measuring the molecular weight of the high molecular weight PTFE and the low molecular weight PTFE, which can be directly specified.

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 a maximum value in a heat of fusion curve when the temperature of PTFE that has not undergone heating to a temperature of 300 ℃ or higher is raised at a rate of 10 ℃/min using a differential scanning calorimeter [ DSC ].

In the heat of fusion curve when the temperature of PTFE which has not been heated to 300 ℃ or higher in the heating history is raised at a rate of 10 ℃/min by a differential scanning calorimeter [ DSC ], the high molecular weight PTFE preferably has at least 1 endothermic peak in the range of 333 to 347 ℃ 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 by-product or decomposed product of the surfactant by-produced by the surfactant, and the residual monomer can be reused by recovering the surfactant, the by-product or decomposed product of the surfactant by-produced by the surfactant, and the residual monomer from the waste water produced by the precipitation or washing and/or the exhaust gas produced by the drying step and purifying the recovered materials. 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 carried out 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 0.2 to 8.0 MPa. In the case of producing FEP, the polymerization temperature is more preferably 30 ℃ or higher, still more preferably 40 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is more preferably 130 ℃ or lower, still more preferably 120 ℃ or lower, particularly preferably 110 ℃ or lower, and still more preferably 100 ℃ or lower. The polymerization pressure is preferably 0.5MPa or more, preferably 1.0MPa or more, preferably 1.2MPa or more, more preferably 6.0MPa or less, and still more preferably 5.0MPa or less.

The preferred monomer composition (mass%) of FEP is TFE: HFP (60-95): (5-40), more preferably (85-92): (8-15). The FEP may be further modified with perfluoro (alkyl vinyl ether) as the component 3 in an amount of 0.1 to 2 mass% based on the total monomers.

In the polymerization of 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, if necessary, and then dried to be powdered, followed by melt extrusion to be made into pellets. The aqueous medium in the aqueous dispersion of FEP may contain additives such as nonionic surfactants, water-soluble organic solvents such as water-soluble alcohols, or no water-soluble organic solvents, as necessary.

In addition, as long as the extrusion conditions are generally capable of forming pellets, melt extrusion can be performed by appropriately setting the extrusion conditions.

In the production method of the present invention, the FEP obtained may have-CF at a site of at least one of the polymer main chain and the polymer side chain₃、-CF₂H and the like terminal groups, preferably-COOH, -CH₂OH、-COF、-CF＝CF-、-CONH₂、-COOCH₃The content of isothermically labile groups (hereinafter referred to as "labile end groups") is low or absent.

The unstable terminal group is chemically unstable, and thus not only lowers the heat resistance of the resin, but also causes an increase in the attenuation of the obtained electric wire.

In the production method of the present invention, it is preferable that the polymerization is terminated at every 1X 10⁶Unstable terminal group in number of carbon atoms and-CF ₂The total number of H terminal groups is 50 or less. At each 1X 10⁶The total number of the above groups in the carbon atoms is more preferably less than 20, and still more preferably 5 or less. The above-mentioned unstable terminal group and-CF₂The H end groups may also be absent and all are-CF₃And (3) a 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 them, preferred is fluorinationIn the method of directly contacting the FEP obtained by the present invention with a gas, the contact is preferably performed using a diluted fluorine gas having a fluorine gas concentration of 10 to 50 mass% from the viewpoint of reaction control. The diluted fluorine gas can be obtained by diluting fluorine gas with an inert gas such as nitrogen gas or argon gas. The fluorine gas treatment is carried out at a temperature of, for example, 100 to 250 ℃. The treatment temperature is not limited to the above range, and may be set as appropriate depending on 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 pellets after melt extrusion.

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 FEP powder is produced by drying the FEP obtained by the production method of the present invention and powdering the dried FEP.

The above-mentioned powders may be fluorinated. The method for producing a 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 covering material for electric wires, foamed electric wires, cables, wires, and the like, pipes, films, sheets, filaments, and the like.

(2) In the production method of the present invention, it is preferable that the polymerization of a TFE/perfluoro (alkyl vinyl ether) copolymer such as PFA or MFA is carried out at a polymerization temperature of 10 to 130 ℃ and a polymerization pressure of 0.3 to 6.0 MPa. In the case of producing a TFE/perfluoro (alkyl vinyl ether) copolymer, the polymerization temperature is more preferably 30 ℃ or higher, still more preferably 40 ℃ or higher, and still more preferably 50 ℃ or higher. Further, it is more preferably 120 ℃ or lower, still more preferably 110 ℃ or lower, and still more preferably 100 ℃ or lower. The polymerization pressure is preferably 0.5MPa or more, preferably 1.0MPa or more, more preferably 5.0MPa or less, still more preferably 4.0MPa or less, and particularly preferably 3.0MPa or less.

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).

In the polymerization of the TFE/perfluoro (alkyl vinyl ether) 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 10% by mass based on 100% by mass of the aqueous medium.

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

The aqueous dispersion of a TFE/perfluoro (alkyl vinyl ether) copolymer such as PFA or MFA obtained by the production method of the present invention may be subjected to post-treatment such as concentration, if necessary, and then dried to be powdered, followed by melt extrusion to be made into pellets. The aqueous medium in the aqueous dispersion may contain an additive such as a nonionic surfactant, a water-soluble organic solvent such as a water-soluble alcohol, or no water-soluble organic solvent, as required.

In addition, as long as the extrusion conditions are generally capable of forming pellets, melt extrusion can be performed by appropriately setting the extrusion conditions.

Among the above copolymers, fluorine gas treatment is preferably carried out for the purpose of improving the heat resistance thereof and further enhancing the effect of suppressing the transmission of a reagent in 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 appropriate 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. In the case of using the reactor at atmospheric pressure, the fluorine/inert gas mixture may be continuously passed into the reactor. As a result, the unstable terminal of the above copolymer is converted into-CF₃Terminal, is thermostable.

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

The desired molded article can be obtained by such a molding method, 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 case, a beaker, a filter case, a flowmeter, a pump, a valve, a cock, a socket, a nut, a wire, a heat-resistant wire, and the like.

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

Further, a nonionic surfactant may be appropriately added to an aqueous dispersion of a TFE/perfluoro (alkyl vinyl ether) copolymer such as PFA or MFA, and polyether sulfone, polyamide imide and/or polyimide, and metal powder may be dissolved or dispersed in an organic solvent as necessary to obtain a primer composition. A coating method which can be used for coating a metal surface with a fluororesin, comprising: the primer composition is applied to the surface of the metal, the 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 0 to 100 ℃ and a polymerization pressure of 0.1 to 20 MPa. In the case of producing ETFE, the polymerization temperature is preferably 20 ℃ or higher, more preferably 30 ℃ or higher, and still more preferably 40 ℃ or higher. Further, it is preferably 95 ℃ or lower, more preferably 90 ℃ or lower, and still more preferably 80 ℃ or lower. The polymerization pressure is preferably 0.5MPa or more, preferably 0.8MPa or more, preferably 1.0MPa or more, and preferably 20MPa or less, more preferably 10MPa or less, and still more preferably 5 or less.

The preferred monomer composition (mol%) of ETFE is TFE: ethylene (50-99): (50-1). The ETFE may be further modified with a 3 rd monomer in an amount of 0 to 20 mass% based on the total amount of the monomers. Preferably, TFE: ethylene: a 3 rd monomer ═ (63-94): (27-2): (1-10). The 3 rd monomer is preferably perfluorobutylethylene, 3,3,4,4,5,5,6,6,7,7,8,8, 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, if necessary, and then dried to be powdered, followed by melt extrusion to be made into pellets. The aqueous medium in the aqueous dispersion may contain an additive such as a nonionic surfactant, a water-soluble organic solvent such as a water-soluble alcohol, or no water-soluble organic solvent, as required.

In addition, as long as the extrusion conditions are generally capable of forming pellets, melt extrusion can be performed by appropriately setting the extrusion conditions.

The ETFE sheet may be formed into a sheet 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. Additives may be added to ETFE.

As the additive, a known one 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, the film is useful not only as a film material for a film structure building, but also in, for example, the following materials: 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, storage tank, container inner wall, filter, construction film materials, electronic materials (printed substrate, wiring substrate, etc.), and the like, An insulating film, a release film, or the like), a surface material of a solar cell module, a mirror protective material for solar power generation, a surface material of a solar water heater, or the like.

(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 0 to 100 ℃ and a polymerization pressure of-0.05 to 5.0 MPa. The electrolyte polymer precursor contains a vinyl ether monomer as shown below and is converted into an ion-exchange polymer by hydrolysis. In the case of producing the electrolyte polymer precursor, the polymerization temperature is more preferably 5 ℃ or higher, and still more preferably 10 ℃ or higher. Further, it is more preferably 80 ℃ or lower, and still more preferably 60 ℃ or lower. The polymerization pressure is preferably 0MPa or more, preferably 0.02MPa or more, more preferably 2.0MPa or less, and still more preferably 1.0 MPa or less.

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 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-POZ ¹⁵²Z¹⁵³。X¹⁵¹Represents F, Cl, Br, I, -OR¹⁵¹or-NR¹⁵²R¹⁵³。Z¹⁵¹、Z¹⁵²And Z¹⁵³Same or different, represent-NR¹⁵⁴R¹⁵⁵OR-OR¹⁵⁶。R¹⁵¹、R¹⁵²、R¹⁵³、R¹⁵⁴、R¹⁵⁵And R¹⁵⁶The same or different, represents H, ammonium, an alkali metal, an alkyl group which may contain a fluorine atom, an aryl group, or a sulfonyl group-containing group). 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 an amount of 0 to 20% by 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 thus obtained electrolyte polymer precursor can be subjected to hydrolysis with an alkali solution and treatment with an inorganic acid after, for example, molding into a film shape, and used as a polymer electrolyte membrane for fuel cells, electrolysis devices, redox flow batteries, and the like.

In addition, the hydrolysis may be performed with an alkali solution while maintaining the dispersion state of the electrolyte polymer precursor, thereby obtaining an electrolyte polymer dispersion liquid.

Subsequently, the mixture is heated to 120 ℃ or higher in a pressurized container, and is dissolved in, for example, a water/alcohol mixed solvent to form a solution.

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 suitably set in accordance with other polymerization conditions such as polymerization temperature, and may be usually 0 to 9.8 MPaG.

In the case of producing a TFE/VDF copolymer, the polymerization temperature is preferably 20 ℃ or higher, more preferably 30 ℃ or higher, and still more preferably 40 ℃ or higher. Further, it is preferably 95 ℃ or lower, more preferably 90 ℃ or lower, and still more preferably 80 ℃ or lower. The polymerization pressure is preferably 0.2MPa or more, preferably 0.3MPa or more, preferably 0.5MPa or more, more preferably 5.0MPa or less, more preferably 4.0MPa or less, and still more preferably 3.0MPa or less.

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 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, H, F or Cl, and n11 represents an integer of 0 to 8. Wherein TFE and VDF) are not included, or

Formula (II): CX²¹X²²＝CX²³-O(CX²⁴X²⁵)_n21X²⁶

(in the formula, X²¹～X²⁶Same or different, H, F or Cl, and n21 represents an integer of 0 to 8).

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, from the viewpoint 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 based on 100% by mass of the aqueous medium.

The TFE/VDF copolymer obtained by the polymerization may be subjected to amidation treatment by contacting with aqueous ammonia, ammonia gas or a nitrogen compound which can generate ammonia.

The TFE/VDF copolymer obtained by the above method is also 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 then 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 the aqueous dispersion of the TFE/VDF copolymer as a composite porous film by coating the aqueous dispersion on a porous substrate made of a polyolefin resin. It is also preferable that the inorganic particles and/or the organic particles are dispersed in the aqueous dispersion and applied to the porous substrate to be used as the composite porous film. 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 suitable for use 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 the melt-processable fluororesin obtained by the production method of the present invention is dried and powdered 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, bringing the temperature 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, the monomer in the reaction vessel was purged, the temperature was returned to room temperature, and the reaction was terminated. In this case, the polymer emulsion can be continuously removed from the reaction vessel.

In particular, when a thermoplastic elastomer is produced as the fluororubber, the following method can be used as disclosed in international publication No. 00/01741: the fluoropolymer fine particles are once 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.

In the polymerization of the fluororubber, conditions are selected as appropriate from the viewpoint of controlling the physical properties of the target polymer and the polymerization rate, and the polymerization is carried out at a polymerization temperature of usually-20 to 200 ℃, preferably 5 to 150 ℃, and a polymerization pressure of usually 0.05 to 10MPa, preferably 0.1 to 8 MPa.

In the case of producing fluororubbers, the polymerization temperature is more preferably 10 ℃ or higher, still more preferably 15 ℃ or higher, and particularly preferably 20 ℃ or higher. Further, it is more preferably 130 ℃ or lower, and still more preferably 90 ℃ or lower. The polymerization pressure is preferably 0.5MPa or more, preferably 1.0MPa or more, and more preferably 7.0MPa or less.

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 suitable for reasons of its elastomeric properties obtained in the case of blocking the crystalline growth of the polymer. 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 ether), 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): (20-48): (0-32), more preferably (20-70): (30-48): (0-32), more preferably (32-64): (30-48): (0 to 27). The fluororubbers of this composition exhibit good elastomer 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 radical polymerization initiator may be further activated by a reducing agent (e.g., sodium, potassium or ammonium thiosulfate, phosphite or hypophosphite) or by a readily oxidizable metal compound (e.g., ferrous, cuprous or silver salt). A suitable inorganic free radical polymerization initiator is ammonium persulfate, more preferably used in redox systems.

In the polymerization of the fluororubber, the amount of the polymerization initiator to be added is not particularly limited, but is preferably set to 0.005 to 1.0% by mass, more preferably 0.01 to 0.5% by mass, based on 100% by mass of the total amount of the monomers, from the viewpoint of efficient polymerization.

The polymerization initiator is preferably the above-mentioned water-soluble radical polymerization initiator, and more preferably ammonium persulfate. In the polymerization step, preferably, 0.005% by mass or more of ammonium persulfate is added to 100% by mass of the total amount of the monomers, and more preferably, 0.01% by mass or more of ammonium persulfate is added.

In the polymerization of the fluororubber, a known chain transfer agent may be used, and hydrocarbons, esters, ethers, alcohols, ketones, chlorides, carbonates, and the like may be used, and hydrocarbons, esters, ethers, alcohols, chlorides, iodides, and the like may be used for the thermoplastic elastomer. Among them, acetone and isopropyl alcohol are preferable; in the polymerization of the thermoplastic elastomer, isopentane, diethyl malonate, and ethyl acetate are preferable from the viewpoint that the reaction rate is not easily decreased; from the viewpoint of iodination of polymer ends and availability as a reactive polymer, I (CF) is preferable₂)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 fluororubber obtained by the production method of the present invention has a solid content concentration of 1.0 to 40% by mass at the time of termination of polymerization, 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.

The fluororubber obtained by the production method of the present invention may be prepared into a dispersion suitable for rubber molding by adding a dispersion stabilizer such as a hydrocarbon-containing surfactant, if necessary, and 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 with carbon number of 5 or less and pK of 4.2 or less, and adjusting 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.

In the above-mentioned pH adjustment and the above-mentioned coagulation, either one may be carried out first, but it is preferable to carry out the pH adjustment 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.

The drying is preferably carried out at 40 to 250 ℃, more preferably at 60 to 230 ℃, and still more preferably at 80 to 200 ℃.

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 one 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 one other monomer copolymerizable with vinylidene fluoride. More preferably 50 to 80 mol% of vinylidene fluoride and 50 to 20 mol% of at least one other monomer copolymerizable with vinylidene fluoride.

Examples of the at least one 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), and a general formula (170): CH (CH)₂＝CH-(CF₂)_n-X¹⁷¹(in the formula, X¹⁷¹H or F, n is an integer of 3 to 10), a fluorine-containing monomer, a monomer providing a crosslinking site, and the like; non-fluorinated monomers such as ethylene, propylene, alkyl vinyl ethers, and the like. They may be used individually or in any combination. Among these, at least one selected from the group consisting of TFE, HFP, fluoroalkyl vinyl ether, and CTFE is preferably used. As the fluoroalkyl vinyl ether, a fluorine-containing monomer represented by the general formula (160) is preferable.

Specific examples of the vinylidene fluoride-based fluororubber include VdF/HFP-based rubbers, VdF/HFP/TFE-based rubbers, VdF/CTFE/TFE-based rubbers, VdF/fluorine-containing monomer-based rubbers represented by general formula (100), VdF/fluorine-containing monomer/TFE-based rubbers represented by general formula (100), VdF/perfluoro (methyl vinyl ether) [ PMVE ] ]And VDF/PMVE/TFE rubber, VDF/PMVE/TFE/HFP rubber, and the like. VDF/fluorine-containing monomer rubber represented by the general formula (100) is preferably VDF/CH₂＝CFCF₃Is a rubber; VDF/fluoromonomer/TFE rubber represented by the general formula (100) is preferably VDF/TFE/CH₂＝CFCF₃Is a rubber.

The above VDF/CH₂＝CFCF₃The rubber is preferably a rubber composed of 40 to 99.5 mol% of VDF and CH₂＝CFCF₃0.5 to 60 mol% of a copolymer, more preferably 50 to 85 mol% of VDF 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-containing monomer that provides a crosslinking site.

The fluororubber may be a perfluororubber. The perfluororubber is preferably a perfluororubber containing TFE, and is preferably at least one selected from the group consisting of TFE/fluoromonomer copolymer represented by general formula (160), (130) or (140) and TFE/fluoromonomer represented by general formula (160), (130) or (140)/crosslinking site-providing monomer copolymer.

The composition 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 copolymer.

In the case of a TFE/PMVE/crosslinkable 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/fluorine-containing monomer 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 further preferably 65 to 85/15 to 35.

In the case of TFE/a fluorine-containing monomer represented by the general formula (160), (130) or (140) having 4 to 12 carbon atoms/a monomer copolymer providing a crosslinking site, it 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 further preferably 65 to 84.8/15 to 34.8/0.2 to 3.

If the amount is outside the above range, 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 one selected from the group consisting of a copolymer of TFE/a fluorine-containing monomer represented by the general formula (140)/a fluorine-containing monomer providing a crosslinking site, a copolymer of TFE/a perfluorovinyl ether represented by the general formula (140), a copolymer of TFE/a fluorine-containing monomer represented by the general formula (160), and a copolymer of TFE/a fluorine-containing monomer represented by the general formula (160)/a monomer 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. In addition, the glass transition temperature is preferably 5 ℃ or lower, more preferably 0 ℃ or lower, and further preferably-3 ℃ or lower, from the viewpoint of good cold resistance.

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 (manufactured by Mettler Toedo Co., Ltd., DSC822e), and the temperature of the midpoint of 2 intersections where the extension line of the base line before and after the secondary phase transition of the DSC curve intersects the tangent line at the inflection point of the DSC curve was determined 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 further 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, it 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 deg.C or 140 deg.C at 100 deg.C according to JIS K6300 using Mooney viscometer model MV2000E manufactured by ALPHA TECHNOLOGIES.

The fluororubber obtained by the production method of the present invention may be in any form as long as it is obtained by the above polymerization, and may be an aqueous dispersion having completed polymerization, or may be used in the form of a gum mass (gum) or a briquette (crumbb) obtained by precipitating, drying, or the like the aqueous dispersion having completed polymerization 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 above-mentioned 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.

The gum mass (gum) is a granular small mass made of fluororubber, and the agglomerate (crumb) is a form in which the fluororubber cannot maintain the granular form as a gum mass at room temperature and is fused together to form 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 a polyol, a polyamine, an organic peroxide, organotin, bis (aminophenol) tetramine, bis (thioaminophenol), and the like.

The fluororubber composition is excellent in that it is substantially free of an emulsifier because it is composed of the fluororubber, and is easily crosslinked during molding.

The fluororubber molded body can be obtained by molding the fluororubber. 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, a wire covering, 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.

The aqueous dispersion containing the fluoropolymer is usually obtained by the above polymerization. The fluoropolymer is usually contained in an aqueous dispersion obtained by the polymerization at a concentration of 8 to 50% by mass. In the aqueous 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 average primary particle diameter of the fluoropolymer is, for example, 50 to 500 nm. The lower limit of the average primary particle diameter is preferably 100nm, more preferably 150 nm. The upper limit of the average primary particle diameter is preferably 400nm, more preferably 350 nm.

The average primary particle diameter can be measured by a dynamic light scattering method. The average primary particle size can be measured by a dynamic light scattering method under conditions of 25 ℃, 1.3328 for the refractive index of the solvent (water), 0.8878mPa · s for the viscosity of the solvent (water), and 70 times of accumulation, to prepare an aqueous fluoropolymer dispersion in which the fluoropolymer solid content concentration is adjusted to about 1.0 mass%. As the dynamic light scattering method, for example, ELSZ-1000S (manufactured by Otsuka electronics Co., Ltd.) can be used.

The aqueous dispersion obtained by the above polymerization may be concentrated or subjected to dispersion stabilization treatment to prepare a dispersion, or may be precipitated or coagulated, recovered and dried to prepare a powder or other solid matter.

The surfactant can be suitably used as a dispersant for dispersing the fluoropolymer obtained by polymerization in an aqueous medium.

In the above polymerization, an aqueous dispersion containing particles composed of the above fluoropolymer, the above surfactant, and the above aqueous medium is usually obtained. The aqueous dispersion is obtained by dispersing particles made of a fluoropolymer in an aqueous medium in the presence of the surfactant.

The lower limit of the content of the carboxylic acid type hydrocarbon-containing surfactant in the aqueous dispersion is preferably 10ppb, more preferably 100ppb, further preferably 1ppm, further more preferably 10ppm, and particularly preferably 50ppm with respect to the fluoropolymer. The upper limit value is preferably 100000ppm, more preferably 50000ppm, further preferably 10000ppm, further preferably 5000ppm to the fluoropolymer.

The aqueous dispersion may be any of an aqueous dispersion obtained by the polymerization, a dispersion obtained by concentrating or performing dispersion stabilization treatment on the aqueous dispersion, and an aqueous dispersion obtained by dispersing a powder composed of a fluoropolymer in an aqueous medium in the presence of the surfactant.

As a method for producing the aqueous dispersion, a purified aqueous dispersion may be produced by subjecting an aqueous dispersion obtained by the polymerization to the following steps: (I) a step (I) of contacting the resulting product with an anion exchange resin or a mixed bed comprising an anion exchange resin and a cation exchange resin in the presence of a nonionic surfactant; and/or (II) a step (II) of concentrating the aqueous dispersion so that the solid content concentration is 30 to 70 mass% with respect to 100 mass% of the aqueous dispersion. The nonionic surfactant is not particularly limited, and those described later can be used. The anion exchange resin is not particularly limited, and a known one can be used. In addition, the above-mentioned method of contacting with the anion exchange resin may employ a known method.

As a method for producing the aqueous dispersion, a purified aqueous dispersion can be produced by subjecting the aqueous dispersion obtained by the polymerization to the step (I) and subjecting the aqueous dispersion obtained by the step (I) to the step (II). Alternatively, the purified aqueous dispersion may be produced by performing the step (II) without performing the step (I). The steps (I) and (II) may be repeated, or may be combined.

Examples of the anion exchange resin include resins having a functional group of-N⁺X^-(CH₃)₃Strongly basic anion exchange resin of group (X represents Cl or OH), having-N⁺X^-(CH₃)₃(C₂H₄OH) group (X is the same as above). Specifically, examples thereof include those described in International publication No. 99/62858, International publication No. 03/020836, International publication No. 2004/078836, International publication No. 2013/027850 and International publication No. 2014/084399.

The cation exchange resin is not particularly limited, and examples thereof include those having a functional group of-SO₃ ^-Strongly acidic cation exchange resin having-COO as a functional group^-Among them, a strongly acidic cation exchange resin is preferable, and H is more preferable from the viewpoint of removal efficiency ⁺Strong acid cation exchange resins of the type.

The "mixed bed containing a cation exchange resin and an anion exchange resin" is not particularly limited, and includes a case where both are packed in the same column, a case where both are packed in different columns, a case where both are dispersed in an aqueous dispersion, and the like.

As the above concentration method, a known method is used. Specifically, there are methods described in International publication No. 2007/046482 and International publication No. 2014/084399.

Examples thereof include phase separation, centrifugal sedimentation, cloud point concentration, electric concentration, electrophoresis, filtration treatment using ultrafiltration, filtration treatment using a reverse osmosis membrane (RO membrane), nanofiltration treatment, and the like. The concentration may be such that the fluoropolymer concentration is 30 to 70% by mass depending on the application. The stability of the dispersion may be impaired by concentration, but in this case a dispersion stabilizer may be further added. The dispersion stabilizer may be added with the nonionic surfactant or various other surfactants. As the nonionic surfactant, the nonionic surfactant can be suitably used in the same manner as the nonionic surfactant exemplified as the nucleating agent. The nonionic surfactant preferably does not contain an aromatic moiety.

In addition, the cloud point of a nonionic surfactant is a measure of the solubility of the surfactant in water. The surfactant used in the aqueous dispersion has a cloud point of from about 30 ℃ to about 90 ℃, preferably from about 35 ℃ to about 85 ℃.

The total amount of the dispersion stabilizer is 0.5-20 mass% of the solid content of the dispersion. If less than 0.5 mass%, dispersion stability may be deteriorated; if the amount exceeds 20% by mass, the dispersion effect is not obtained in accordance with the amount of the polymer, and the method is not practical. A more preferable lower limit of the dispersion stabilizer is 2% by mass, and a more preferable upper limit is 12% by mass.

The surfactant can be removed by the above-mentioned concentration operation.

The aqueous dispersion obtained by the above polymerization may be subjected to dispersion stabilization treatment without concentration according to the use, and an aqueous dispersion having a long shelf life may be prepared. The dispersion stabilizer used may be the same as described above.

The use of the aqueous dispersion is not particularly limited, and examples of the direct application in the form of an aqueous dispersion include: a coating layer formed by coating on a substrate, drying, and then baking 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 cast film formed by coating a substrate such as glass on the substrate, drying the substrate, immersing the substrate in water as needed, and peeling the substrate to obtain a thin film include an aqueous dispersion type paint, a tent film, a conveyor belt, a printed circuit board (CCL), an adhesive for an electrode, a water repellent for an electrode, and the like.

The aqueous dispersion can be used as a coating aqueous coating material by blending a known blending agent such as a pigment, a thickener, a dispersant, a defoaming agent, an antifreezing agent, and a film-forming aid, or further compounding with another polymer compound.

In addition, the additive can be used for adhesives, binders, anti-dripping agents and other compounds for inhibiting the fall-off of the active material of the electrode, dust-inhibiting treatment for preventing the flying of sand, dust and the like, and the like.

In order to adjust the viscosity of the aqueous dispersion or to improve the miscibility with a pigment, a filler, or the like, an anionic surfactant may be preferably contained. The anionic surfactant may be appropriately added within a range that causes no problem in terms of economy and environment.

Examples of the anionic surfactant include a non-fluorinated anionic surfactant and a fluorine-containing anionic surfactant, and a non-fluorinated anionic surfactant containing no fluorine, that is, a hydrocarbon anionic surfactant is preferable.

For the purpose of adjusting the viscosity, the type of the anionic surfactant is not particularly limited as long as it is known, and for example, the anionic surfactants described in international publication No. 2013/146950 and international publication No. 2013/146947 can be used. Examples thereof include anionic surfactants having a saturated or unsaturated aliphatic chain having 6 to 40 carbon atoms, preferably 8 to 20 carbon atoms, and more preferably 9 to 13 carbon atoms. The saturated or unsaturated aliphatic chain may be either a straight chain or a branched chain, or may have a cyclic structure. The hydrocarbon may be aromatic or may have an aromatic group. The hydrocarbon may have a hetero atom such as oxygen, nitrogen, or sulfur.

Examples of the anionic surfactant include alkylsulfonates, alkylsulfates, alkylarylsulfates, and salts thereof; aliphatic (carboxylic) acids and salts thereof; alkyl phosphates, alkyl aryl phosphates, or salts thereof; and the like, among which alkyl sulfonates, alkyl sulfates, aliphatic carboxylic acids or salts thereof are preferred.

The alkyl sulfate or a salt thereof is preferably ammonium lauryl sulfate, sodium lauryl sulfate or the like.

As the aliphatic carboxylic acid or a salt thereof, succinic acid, capric acid, undecanoic acid, undecylenic acid, lauric acid, hydrogenated dodecanoic acid, or a salt thereof is preferable.

The amount of the anionic surfactant to be added depends on the kind of the anionic surfactant or other compounding agent, and is preferably 10ppm to 5000ppm based on the solid content of the fluoropolymer.

The lower limit of the amount of the anionic surfactant to be added is more preferably 50ppm or more, and still more preferably 100ppm or more. If the amount of addition is too small, the viscosity adjusting effect is poor.

The upper limit of the amount of the anionic surfactant to be added is more preferably 3000ppm or less, and still more preferably 2000ppm or less. If the amount is too large, the mechanical stability and storage stability of the aqueous dispersion may be impaired.

For the purpose of adjusting the viscosity of the aqueous dispersion, for example, methylcellulose, alumina sol, polyvinyl alcohol, carboxylated vinyl polymer, and the like may be blended in addition to the anionic surfactant.

For the purpose of adjusting the pH of the aqueous dispersion, a pH adjuster such as ammonia water may be added.

The aqueous dispersion may contain other water-soluble polymer compounds in a range not impairing the characteristics of the aqueous dispersion, if necessary.

The other water-soluble polymer compound is not particularly limited, and examples thereof include polyethylene oxide (dispersion stabilizer), polyethylene glycol (dispersion stabilizer), polyvinylpyrrolidone (dispersion stabilizer), phenol resin, urea resin, epoxy resin, melamine resin, polyester resin, polyether resin, acrylic silicone resin, silicone polyester resin, and polyurethane resin. In addition, preservatives such as isothiazolone, azole, bronopol, chlorothalonil, methylsulfonyltetrachloropyridine, carbendazim, 2- [ (dichlorofluoromethyl) -thio ] -1H-isoindole-1, 3- (2H) -dione (Fluor Folpet), sodium diacetate, diiodomethyl-p-tolylsulfone and the like may be contained.

The surfactant, the by-product or decomposed product of the surfactant by-produced by the surfactant, and the residual monomer can be reused by recovering the surfactant, the by-product or decomposed product of the surfactant by-produced by the surfactant, and the residual monomer from the waste water produced by the precipitation or washing and/or the exhaust gas produced by the drying step and purifying the recovered materials. 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 carried out by the method described in Japanese patent publication No. 2011-520020.

The method for recovering and purifying the surfactant, the decomposition product or by-product of the surfactant by-produced by the surfactant, and the residual monomer from the waste water produced by the precipitation, the waste water produced by the washing and the exhaust gas produced by the drying step is not particularly limited, and conventionally known methods can be used, and examples thereof include the methods described in U.S. patent application publication No. 2007/15937, U.S. patent application publication No. 2007/25902, and U.S. patent application publication No. 2007/27251, and specifically, the following methods can be mentioned.

Examples of the method for recovering the surfactant, the decomposed product or by-product of the surfactant by-produced from the surfactant, and the residual monomer from the wastewater include the following methods: the wastewater is brought into contact with adsorbent particles such as ion exchange resin, activated carbon, silica gel, clay, zeolite, etc., to adsorb the surfactant, etc., and then the wastewater is separated from the adsorbent particles. If the adsorbent particles having the surfactant or the like adsorbed thereon are incinerated, the release of the surfactant or the like into the environment can be prevented.

The surfactant or the like may be desorbed and eluted from the ion exchange resin particles having the surfactant or the like adsorbed thereon by a known method and recovered. For example, when the ion exchange resin particles are anion exchange resin particles, the surfactant and the like can be eluted by bringing an inorganic acid into contact with the anion exchange resin. Subsequently, when a water-soluble organic solvent is added to the obtained dissolution liquid, the separation into 2 phases is usually performed, and therefore, the surfactant and the like can be recovered by recovering and neutralizing a lower phase containing the surfactant and the like. Examples of the water-soluble organic solvent include polar solvents such as alcohols, ketones, and ethers.

Other methods for recovering the surfactant and the like from the ion exchange resin particles include a method using an ammonium salt and a water-soluble organic solvent, and a method using an alcohol and a desired acid. In the latter method, the ester derivative of the surfactant or the like is produced, and thus can be easily separated from the alcohol by distillation.

In the case where the above-mentioned waste water contains fluoropolymer particles or other solid components, it is preferred to remove them before the waste water is brought into contact with the adsorbent particles. Examples of the method for removing fluoropolymer particles and other solid components include a method of precipitating them by adding an aluminum salt or the like and then separating the wastewater from the precipitate, an electrocoagulation method, and the like. The removal can also be performed by a mechanical method, and examples thereof include a cross-flow filtration method, a depth filtration method, and a precoat filtration method.

From the viewpoint of productivity, the concentration of the unagglomerated fluoropolymer in the wastewater is preferably low, and the concentration is more preferably less than 0.4 mass%, particularly preferably less than 0.3 mass%.

As a method for recovering the surfactant and the like from the exhaust gas, there is a method of contacting the exhaust gas with deionized water, an alkaline aqueous solution, an organic solvent such as a glycol ether solvent and the like using a scrubber to obtain a scrubbing solution containing the surfactant and the like. When a high-concentration aqueous alkali solution is used as the aqueous alkali solution, the scrubbing solution can be recovered in a phase-separated state of the surfactant and the like, and thus the surfactant and the like can be easily recovered and reused. Examples of the alkali compound include alkali metal hydroxides and quaternary ammonium salts.

The scrubbing solution containing the surfactant and the like can be concentrated using a reverse osmosis membrane or the like. The concentrated scrubbing solution usually contains fluoride ions, but the above-mentioned surfactant and the like can be easily reused by further adding alumina after concentration to remove the fluoride ions. Alternatively, the adsorbent particles may be brought into contact with a scrubbing solution to adsorb the surfactant and the like, and the surfactant and the like may be recovered by the above-described method.

The surfactant and the like recovered by any of the above methods can be reused for the production of a fluoropolymer.

The fluoropolymer can be obtained by the production method of the present invention. A composition containing the fluoropolymer obtained by the above-described production method is also an embodiment of the present invention.

The above production method can provide a fluoropolymer substantially free from a compound represented by the general formula (3) below and a composition containing the fluoropolymer.

The present invention also relates to a composition containing a fluorine-containing polymer, which is characterized by containing substantially no compound represented by the following general formula (3).

General formula (3): (H- (CF)₂)₈-SO₃)_qM²

(in the formula, M²Is H, a metal atom, NR⁵ ₄With or without An imidazolium, a pyridinium, with or without substituents, or a phosphonium, with or without substituents. q is 1 or 2. )

The fluoropolymer is the same as described above.

The composition of the present invention contains substantially no compound represented by the general formula (3). The compound represented by the general formula (3) is not substantially contained, and for example, the content of the compound represented by the general formula (3) may be 1000ppb or less with respect to the fluoropolymer. The content of the compound represented by the general formula (3) is preferably 500ppb or less, more preferably 100ppb or less, further preferably 25ppb or less, particularly preferably 15ppb or less, and further more preferably 10ppb or less with respect to the fluoropolymer. The lower limit is not particularly limited, and may be 0ppb or 1 ppb.

When the composition of the present invention is an aqueous dispersion, the limit of quantitation is about 10 to 100ppb when the content of the compound represented by the general formula (3) is measured by the method described later, but the limit of quantitation can be lowered by concentration. The concentration may be repeated several times.

One embodiment of the present invention may be a composition as an aqueous dispersion, a composition as a powder, a composition as a pellet, a composition as a molded article, or a composition as a molded article. The aqueous dispersion may be a dispersion in which polymerization is completed, or may be a dispersion obtained by processing a dispersion in which polymerization is completed. For example, a nonionic surfactant or the like may be added for reasons of mechanical stability and storage stability.

The aqueous dispersion is a dispersion system having an aqueous medium as a dispersion medium and the above-mentioned fluoropolymer as a dispersoid. The aqueous medium is not particularly limited as long as it is a liquid containing water, and may contain, for example, an organic solvent such as alcohol, ether, ketone, paraffin, or the like in addition to water.

When a fluoropolymer is produced using a hydrocarbon surfactant, the resulting aqueous dispersion may contain a compound represented by the following general formula (4), (4 '), (5) or (5'). One embodiment of the present invention is a composition containing these compounds in the following ranges.

One embodiment of the present invention relates to a composition containing 100ppb or more of a compound represented by the following general formula (4) with respect to a fluorine-containing polymer. The upper limit of the content of the compound represented by the general formula (4) is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (4) may be 500ppb or 1000 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention also relates to a composition containing 100ppb or more of the compound represented by the following general formula (4') relative to the fluoropolymer. The upper limit of the content of the compound represented by the general formula (4') is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (4') may be 500ppb or 1000 ppb.

General formula (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention also relates to a composition containing 100ppb or more of the compound represented by the following general formula (4) with respect to a fluoropolymer and/or containing 100ppb or more of the compound represented by the following general formula (4') with respect to a fluoropolymer. The upper limit of the content of the compound represented by the general formula (4) is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (4) may be 500ppb or 1000 ppb. The upper limit of the content of the compound represented by the general formula (4') is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (4') may be 500ppb or 1000 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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 (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 100ppb or more of a compound represented by the following general formula (5) with respect to a fluorine-containing polymer. The upper limit of the content of the compound represented by the general formula (5) is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (5) may be 500ppb or 1000 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 100ppb or more of a compound represented by the following general formula (5') relative to a fluorine-containing polymer. The upper limit of the content of the compound represented by the general formula (5') is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (5') may be 500ppb or 1000 ppb.

General formula (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention also relates to a composition containing 100ppb or more of the compound represented by the following general formula (5) with respect to a fluoropolymer and/or containing 100ppb or more of the compound represented by the following general formula (5') with respect to a fluoropolymer. The upper limit of the content of the compound represented by the general formula (5) is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (5) may be 500ppb or 1000 ppb. The upper limit of the content of the compound represented by the general formula (5') is not particularly limited, and may be 1000000ppb, 100000ppb, 10000ppb or 5000 ppb. The lower limit of the content of the compound represented by the general formula (5') may be 500ppb or 1000 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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 (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, 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. )

When the composition of the present invention is an aqueous dispersion, the content of the compound represented by the following general formula (4), (4 '), (5) or (5') may be in the following range.

In addition, a nonionic surfactant may be added to the aqueous dispersion to improve stability. The nonionic surfactant is not particularly limited, and conventionally known nonionic surfactants can be used.

One embodiment of the present invention relates to a composition containing a compound represented by the following general formula (4) in an amount of 1000ppb or less relative to a fluorine-containing polymer, and containing 1% by mass or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (4) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing a compound represented by the following general formula (4') in an amount of 1000ppb or less relative to a fluoropolymer and containing 1% by mass or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (4') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing at least either 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 with respect to a fluoropolymer, the content of the compound represented by the general formula (4') is 1000ppb or less with respect to the fluoropolymer, and the composition contains 1 mass% or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (4) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (4) is not particularly limited, and may be 0ppb or 1 ppb. The content of the compound represented by the general formula (4') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (4') is not particularly limited, and may be 0ppb or 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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 (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing a compound represented by the following general formula (5) in an amount of 1000ppb or less relative to a fluorine-containing polymer, and containing 1% by mass or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (5) is preferably 500ppb or less, more preferably 100ppb or less, particularly preferably 25ppb or less, further preferably 15ppb or less, and further preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing a compound represented by the following general formula (5') in an amount of 1000ppb or less relative to a fluoropolymer and containing 1% by mass or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (5') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 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 with respect to a fluoropolymer, the content of the compound represented by the general formula (5') is 1000ppb or less with respect to the fluoropolymer, and the composition contains 1% by mass or more of a nonionic surfactant. The upper limit of the content of the nonionic surfactant is preferably 10% by mass, for example. The content of the compound represented by the general formula (5) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (5) is not particularly limited, and may be 0ppb or 1 ppb. The content of the compound represented by the general formula (5') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (5') is not particularly limited, and may be 0ppb or 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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 (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, 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. )

When a fluoropolymer is produced using a hydrocarbon surfactant, the resulting fluoropolymer powder may contain a compound represented by the following general formula (1), (2), (4 '), (5) or (5'). When the composition of the present invention is a powder, the content of the compound represented by the general formula (1), (2), (4 '), (5) or (5') may be in the following range.

One embodiment of the present invention relates to a composition containing 1000ppb or less of a compound represented by the following general formula (4) relative to a fluorine-containing polymer. The content of the compound represented by the general formula (4) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 1000ppb or less of a compound represented by the following general formula (4') relative to a fluorine-containing polymer. The content of the compound represented by the general formula (4') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing at least either 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 with respect to a fluoropolymer, and the content of the compound represented by the general formula (4') is 1000ppb or less with respect to the fluoropolymer. The content of the compound represented by the general formula (4) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (4) is not particularly limited, and may be 0ppb or 1 ppb. The content of the compound represented by the general formula (4') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (4') is not particularly limited, and may be 0ppb or 1 ppb.

General formula (4): (H- (CF)₂)₇-COO)_pM¹

(in the formula, 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 (4'): (H- (CF)₂)₈-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 1000ppb or less of a compound represented by the following general formula (5) relative to a fluorine-containing polymer. The content of the compound represented by the general formula (5) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 1000ppb or less of a compound represented by the following general formula (5') relative to a fluorine-containing polymer. The content of the compound represented by the general formula (5') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit is not particularly limited, and may be 1 ppb.

General formula (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, 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. )

One embodiment of the present invention relates to a composition containing 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 with respect to a fluoropolymer and the content of the compound represented by the general formula (5') is 1000ppb or less with respect to the fluoropolymer. The content of the compound represented by the general formula (5) is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (5) is not particularly limited, and may be 0ppb or 1 ppb. The content of the compound represented by the general formula (5') is more preferably 500ppb or less, still more preferably 100ppb or less, particularly preferably 25ppb or less, still more preferably 15ppb or less, and still more preferably 10ppb or less. The lower limit of the content of the compound represented by the general formula (5') is not particularly limited, and may be 0ppb or 1 ppb.

General formula (5): (H- (CF)₂)₁₃-COO)_pM¹

(in the formula, 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 (5'): (H- (CF)₂)₁₄-COO)_pM¹

(in the formula, M¹Is H, a metal atom, NR⁵ ₄Imidazolium with or without substituent, pyridine with or without substituentA pyridinium, or a phosphonium with or without substituents. p is 1 or 2. )

One embodiment of the present invention relates to a composition wherein, in compounds represented by the following general formula (2), the content of a compound having n of 4 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 5 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 6 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 7 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 8 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 9 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 10 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 11 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 12 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 13 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having n of 14 is 1000ppb or less with respect to the fluoropolymer, the content of a compound having n of 15 is 1000ppb or less with respect to the fluoropolymer, the content of a compound having n of 16 is 1000ppb or less with respect to the fluoropolymer, the content of a compound having n of 17 is 1000ppb or less with respect to the fluoropolymer, the content of a compound having n of 18 is 1000ppb or less with respect to the fluoropolymer, the content of a compound having n of 19 is 1000ppb or less with respect to the fluoropolymer, and the content of a compound having n of 20 is 1000ppb or less with respect to the fluoropolymer.

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 each compound having n of 4 to 20 is more preferably 500ppb or less, further preferably 100ppb or less, particularly preferably 25ppb or less, further preferably 15ppb or less, and further preferably 10ppb or less. The lower limit is not particularly limited, and may be 0ppb or 1 ppb. In the composition of the present invention, the content of any one of the compounds represented by the general formula (2) may be 0 ppb.

One embodiment of the present invention relates to a composition wherein, among compounds represented by the following general formula (1), the content of a compound having m 3 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 4 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 5 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 6 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 7 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 8 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 9 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 10 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 11 is 1000ppb or less with respect to a fluoropolymer, the content of a compound having m 12 is 1000ppb or less with respect to a fluoropolymer, a method for producing a fluoropolymer, and a composition comprising, The content of the compound having m of 13 is 1000ppb or less with respect to the fluoropolymer, the content of the compound having m of 14 is 1000ppb or less with respect to the fluoropolymer, the content of the compound having m of 15 is 1000ppb or less with respect to the fluoropolymer, the content of the compound having m of 16 is 1000ppb or less with respect to the fluoropolymer, the content of the compound having m of 17 is 1000ppb or less with respect to the fluoropolymer, the content of the compound having m of 18 is 1000ppb or less with respect to the fluoropolymer, and the content of the compound having m of 19 is 1000ppb or less with respect 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. )

The content of each compound having m of 3 to 19 is more preferably 500ppb or less, further preferably 100ppb or less, particularly preferably 25ppb or less, further preferably 15ppb or less, and further preferably 10ppb or less. The lower limit is not particularly limited, and may be 0ppb or 1 ppb. One embodiment of the present invention relates to a composition containing any one of the compounds represented by the above general formula (1).

In the above general formula (1), (2), (3), (4 '), (5) or (5 '), 4R ' s⁵May 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.

One embodiment of the present invention relates to a composition as a powder, and when the composition of the present invention is a powder, the powder preferably has an average particle diameter of 0.5 to 2000 μm. A more preferable lower limit of the average particle diameter is 1 μm, a more preferable upper limit is 1000 μm, and a further more preferable upper limit is 800 μm.

In the present specification, in the case of low molecular weight PTFE, particle size distribution measurement was performed at a pressure of 0.1MPa for a measurement time of 3 seconds using a laser diffraction particle size distribution measuring apparatus (manufactured by japan laser corporation) without using a cascade, and the average particle size was a particle size corresponding to 50% of the integral of the obtained particle size distribution.

In the case of high molecular weight PTFE, the average particle diameter is a value measured in accordance with JIS K6891.

The color tone L of the powder after firing is preferably 50 or less. The color tone L is more preferably 45 or less, still more preferably 40 or less, particularly preferably 35 or less, and still more preferably 30 or less.

The sample for measuring color tone L was obtained by molding 4.0g of PTFE powder into a disk-shaped PTFE molded article having an inner diameter of 28.6mm and a thickness of about 4 mm.

The color tone L of the powder was measured by a colorimeter (CIELAB color scale) in accordance with JIS Z8781-4.

The firing is carried out by heat treatment for 10 minutes in an electric furnace heated to 385 ℃.

In the composition of the present invention, the rate of change in color tone Δ L before and after the fluorination treatment is preferably 70% or more. The color tone change rate Δ L is more preferably 80 or more, and still more preferably 90 or more.

The tone change rate Δ L is defined by the following equation.

ΔL*(％)＝(L*_{Tertiary amine}L*_i)/(L*_Std-L*_i)×100

L*_iInitial color, measured value of L in CIELAB scale of PTFE before fluorination treatment.

L*_tMeasurement of L in CIELAB scale of fluorinated treated PTFE.

L*_Std＝87.3

The fluorination treatment is carried out by using fluorine gas (F) as a fluorine radical source₂) A mixed gas (fluorine/nitrogen (volume ratio) ═ 20/80) diluted with nitrogen was continuously introduced into the reactor heated to 150 ℃ or higher at a flow rate of about 50cc/min under atmospheric pressure for 480 minutes (8 hours).

In the composition of the present invention, as described in examples described later, the content of the compound represented by the general formula (1), (2), (3), (4 '), (5) or (5') is a value measured by liquid chromatography mass spectrometry.

In the composition of the present invention, as described in examples described later, the content of the compound represented by the general formula (1), (2), (3), (4 '), (5) or (5') is a value measured by liquid chromatography mass spectrometry.

In the composition of the present invention, the fluoropolymer is preferably polymerized using a hydrocarbon surfactant.

The composition of the present invention may comprise a hydrocarbon based surfactant. Examples of the hydrocarbon surfactant include the above-mentioned carboxylic acid type hydrocarbon-containing surfactants.

In the composition, a conventionally known additive such as a pigment or a filler may be added in addition to the fluoropolymer and the hydrocarbon surfactant. The additives may be used in a range not to impair the effects of the present invention.

The composition of the present invention can be produced by using a carboxylic acid-based surfactant or a combination of a carboxylic acid-based surfactant and a specific polymerization initiator.

Examples of the carboxylic acid-based surfactant include the above-mentioned carboxylic acid-type hydrocarbon-containing surfactants.

Examples of the specific polymerization initiator include a water-soluble radical polymerization initiator and a redox initiator.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples thereof include ammonium salts, potassium salts, sodium salts, tert-butyl peroxymaleate, tert-butyl hydroperoxide and the like of persulfuric acid, percarbonic acid and the like, and the amount thereof to be used may be 0.1 to 20 times the amount of the peroxide.

In addition, 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 and 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, manganese triacetate/oxalic acid, cerium ammonium nitrate/oxalic acid, bromate, etc., and potassium permanganate/oxalic acid is 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 compositions of the present invention preferably contain substantially no fluorosurfactant. In the composition of the present invention, "the fluorosurfactant is not substantially contained" means that the amount of the fluorosurfactant relative to the fluoropolymer is 10ppm or less. The content of the fluorinated surfactant is preferably 1ppm or less, more preferably 100ppb or less, still more preferably 10ppb or less, still more preferably 1ppb or less, and particularly preferably the detection limit or less of the fluorinated surfactant obtained by measurement by liquid chromatography-mass spectrometry (LC/MS).

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 dispersion, powder, molded body, pellet, or fluoropolymer obtained by pulverizing the molded body or fluoropolymer obtained by pulverizing the pellet is extracted into an organic solvent of methanol, and molecular weight information is selected from an LC/MS spectrum of the extract liquid, and it is confirmed that the molecular weight information matches the structural formula of the surfactant as a candidate.

Then, an aqueous solution having a concentration of 5 levels or more was prepared for the confirmed surfactant, and LC/MS analysis was performed for each concentration to prepare a calibration curve with respect to the area of the region.

The aqueous dispersion or powder obtained or the powder obtained by pulverizing the molded article can be subjected to soxhlet extraction with methanol, and the extract can be subjected to LC/MS analysis, whereby quantitative measurement can be performed.

The fluorinated surfactant is the same as the fluorinated surfactant exemplified above in the production method of the present invention. 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-containing surfactant 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 include compounds represented by the general formula (N)¹) 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) The compounds shown. More specifically, there may be mentioned perfluorocarboxylic acid (I) represented by the general formula (I), ω -H perfluorocarboxylic acid (II) represented by the general formula (II), perfluoropolyether carboxylic acid (III) represented by the general formula (III), perfluoroalkylalkylene carboxylic acid (IV) represented by the general formula (IV), perfluoroalkoxy fluorocarboxylic acid (V) represented by the general formula (V), and perfluoro alkyl group fluorocarboxylic acid (V) represented by the general formula (V) A perfluoroalkylsulfonic acid (VI) represented by the formula (VI), an ω -H perfluorosulfonic acid (VII) represented by the formula (VII), a perfluoroalkylenesulfonic acid (VIII) represented by the formula (VIII), an alkylidenecarboxylic acid (IX) represented by the formula (IX), a fluorocarboxylic acid (X) represented by the formula (X), an alkoxyfluorosulfonic acid (XI) represented by the formula (XI), and a compound (XII) represented by the formula (XII).

The invention also relates to a molded body made of the composition. The molded article is preferably a stretched article. Examples of the stretched product include, but are not limited to, a yarn, a tube, a tape, a film (a uniaxially stretched film, a biaxially stretched film), and the like.

The composition of the present invention can also be produced by preparing a fluoropolymer by the above-mentioned method for producing a fluoropolymer and then treating the fluoropolymer by the following method or the like.

The stretched body is a porous body having a high porosity, and 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.

Specific applications are exemplified below.

Field of electrochemistry

Dielectric prepreg, EMI shielding material, heat transfer material, and the like. More specifically, 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 semiconductor liquid filtration filter (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 backwash type liquid filtration filter (for industrial wastewater treatment), and the like.

General field of consumable materials

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

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 augmentation materials), head and neck articles (dura mater substitutes), oral health (tissue regeneration medicine), plastic surgery (taping), and the like.