阅读说明：本技术 分散液 (Dispersion liquid ) 是由 山边敦美 细田朋也 笠井涉 寺田达也 于 2019-10-01 设计创作，主要内容包括：提供一种分散液,其包含液态分散介质、四氟乙烯类聚合物的粉末和规定的氟类分散剂,具有优异的分散安定性、粘度、色调等分散物性和触变比、粘接性、透明性、消泡性、不易掉粉等树脂层形成物性。本发明的分散液包含液态分散介质、四氟乙烯类聚合物的粉末和分散剂,所述粉末分散于所述液态分散介质中。所述分散剂为具有含氟部位和仲羟基部位或叔羟基部位的化合物。(Disclosed is a dispersion which comprises a liquid dispersion medium, a tetrafluoroethylene polymer powder and a predetermined fluorine-containing dispersant, and which has excellent dispersion properties such as dispersion stability, viscosity and hue, and resin layer-forming properties such as thixotropic ratio, adhesiveness, transparency, defoaming property and resistance to powder falling. The dispersion liquid of the present invention comprises a liquid dispersion medium, a powder of a tetrafluoroethylene-based polymer, and a dispersant, the powder being dispersed in the liquid dispersion medium. The dispersant is a compound having a fluorine-containing site and a secondary or tertiary hydroxyl site.)

1. A dispersion liquid which comprises a liquid dispersion medium, a tetrafluoroethylene polymer powder and a dispersant, wherein the powder is dispersed in the liquid dispersion medium, and the dispersant is a compound having a fluorine-containing site and a secondary or tertiary hydroxyl site.

2. The dispersion liquid according to claim 1, wherein the powder has a cumulative 50% diameter on a volume basis of 0.05 to 6 μm.

3. The dispersion as claimed in claim 1 or 2, wherein the secondary or tertiary hydroxyl moiety is-CH (CH)₃)OH、-CH(CH₂CH₃) OH or-C (CH)₃)₂OH。

4. The dispersion liquid according to any one of claims 1 to 3, wherein the fluorine-containing site is a polyfluoroalkyl group, a polyfluoroalkyl group containing an etheric oxygen atom, or a polyfluoroalkenyl group.

5. The dispersion as claimed in any one of claims 1 to 4, wherein the dispersant is of the formula R^F(OQ¹)_m-(OQ²)_nA compound represented by the formula OH,

in the formula, R^FRepresents a polyfluoroalkyl group or a polyfluoroalkyl group containing an etheric oxygen atom, Q¹Represents methylene, dimethylene, trimethylene or tetramethylene, Q²Represents 1, 2-propylene, propylene or isopropylene, m is an integer of 4 to 16, and n is an integer of 1 to 3.

6. The dispersion as claimed in claim 5, wherein m is an integer of 4 to 10.

7. A dispersion as claimed in claim 5 or 6, wherein n is 1.

8. The dispersion liquid according to any one of claims 1 to 7, wherein the liquid dispersion medium is an aqueous medium.

9. The dispersion liquid according to any one of claims 1 to 8, wherein the tetrafluoroethylene-based polymer is a polymer comprising a tetrafluoroethylene-based unit and a perfluoro (alkyl vinyl ether) -based unit, a hexafluoropropylene-based unit or a fluoroalkylethylene-based unit.

10. The dispersion liquid according to claim 9, wherein the tetrafluoroethylene-based polymer further comprises a unit having a functional group.

11. The dispersion liquid according to any one of claims 1 to 10, wherein the tetrafluoroethylene-based polymer contains 99.5 mol% or more of units based on tetrafluoroethylene with respect to all units contained in the polymer.

12. The dispersion liquid according to any one of claims 1 to 11, wherein the tetrafluoroethylene-based polymer contains more than 0.5 mol% of units based on a comonomer other than tetrafluoroethylene, relative to all units contained in the polymer.

13. The dispersion liquid according to any one of claims 1 to 12, wherein the tetrafluoroethylene-based polymer has at least 1 functional group selected from a carbonyl group-containing group, a hydroxyl group, an epoxy group, an amide group, an amino group and an isocyanate group.

14. A method for producing a laminate, which comprises applying the dispersion liquid according to any one of claims 1 to 13 to the surface of a substrate and heating the same to form a resin layer containing a tetrafluoroethylene polymer, thereby obtaining a laminate in which the substrate and the resin layer are laminated in this order.

15. A method for producing a coated woven fabric, which comprises impregnating a woven fabric with the dispersion liquid according to any one of claims 1 to 13, and drying the woven fabric to obtain a woven fabric coated with a tetrafluoroethylene polymer-containing resin layer.

Technical Field

The present invention relates to a dispersion liquid containing a liquid dispersion medium, tetrafluoroethylene polymer powder, and a predetermined fluorine-based dispersant, a method for producing a laminate using the dispersion liquid, and a method for producing a coated woven fabric.

Background

Tetrafluoroethylene polymers such as polytetrafluoroethylene, copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether), and copolymers of tetrafluoroethylene and hexafluoropropylene are excellent in physical properties such as mold release properties, electrical characteristics, water-and oil-repellency, chemical resistance, weather resistance, and heat resistance, and are used in various industrial applications.

Among them, if the dispersion of tetrafluoroethylene polymer powder is applied to the surface of a substrate, a layer (resin layer) of the tetrafluoroethylene polymer can be formed on the surface to impart the above-mentioned physical properties to the substrate, and therefore, it can be used as a coating agent.

Patent document 1 describes a nonaqueous dispersion liquid containing a nonaqueous medium, tetrafluoroethylene polymer powder, and a monomer represented by the formula R^pf-(OQ^p1)_q(OQ^p2)_rA compound represented by-OH (wherein R is^pfRepresents a C1-12 fluoroalkyl group, Q^p1And Q^p1Represents an alkylene group having 2 to 4 carbon atoms, q represents an integer of 1 to 12, and r represents an integer of 0 to 12).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-225710

Disclosure of Invention

Technical problem to be solved by the invention

The tetrafluoroethylene polymer is inherently low in surface tension and small in interaction with other materials. Therefore, a dispersion liquid in which the powder is dispersed in an organic dispersion medium has low dispersibility, and the powder is likely to precipitate in a cake form. Furthermore, the precipitated powder is difficult to redisperse. The nonaqueous dispersion described in patent document 1 contains the above-mentioned compound as a dispersant, and the dispersibility and redispersibility are considered to be excellent.

On the other hand, in recent years, the applications and use forms of the dispersion have been expanded, and the kinds of powders (the molecular structure of the polymer, the properties of the powder, and the like) of the tetrafluoroethylene polymer and the kinds of the dispersion medium to be used have been diversified. Therefore, the dispersion liquid is required to be chemically inert, and to be excellent in other dispersion physical properties such as viscosity and color tone, and resin layer formation physical properties such as a thixotropic ratio, adhesiveness, transparency, defoaming property, and resistance to powder falling, in addition to dispersibility and redispersibility of the powder.

After diligent studies, the present inventors have found that a predetermined fluorine-based compound having a secondary hydroxyl group site or a tertiary hydroxyl group site can improve the other dispersion properties and the resin layer-forming properties in addition to the dispersibility and redispersibility thereof as a dispersant for a dispersion liquid of a tetrafluoroethylene-based polymer.

Technical scheme for solving technical problem

The present invention has the following technical contents.

[1] A dispersion liquid which comprises a liquid dispersion medium, a tetrafluoroethylene polymer powder and a dispersant, wherein the powder is dispersed in the liquid dispersion medium, and the dispersant is a compound having a fluorine-containing site and a secondary or tertiary hydroxyl site.

[2] The dispersion liquid according to [1], wherein the powder has a cumulative 50% diameter of 0.05 to 6 μm on a volume basis.

[3]Such as [1]]Or [2]]The dispersion according to (1), wherein the secondary hydroxyl group site or the tertiary hydroxyl group site is-CH (CH)₃)OH、-CH(CH₂CH₃) OH or-C (CH)₃)₂OH。

[4] The dispersion liquid according to any one of [1] to [3], wherein the fluorine-containing site is a polyfluoroalkyl group, a polyfluoroalkyl group containing an etheric oxygen atom, or a polyfluoroalkenyl group.

[5]Such as [1]]～[4]The dispersion of any one of the above, wherein the dispersant is of the formula R^F(OQ¹)_m-(OQ²)_nA compound represented by OH.

(in the formula, R^FRepresents a polyfluoroalkyl group or a polyfluoroalkyl group containing an etheric oxygen atom, Q¹Represents methylene, dimethylene, trimethylene or tetramethylene, Q²Represents 1, 2-propylene, propylene or isopropylene group, m is an integer of 4 to 16, n is an integer of 1 to 3)

[6] The dispersion as described in [5], wherein m is an integer of 4 to 10.

[7] The dispersion liquid according to [5] or [6], wherein n is 1.

[8] The dispersion liquid according to any one of [1] to [7], wherein the liquid dispersion medium is an aqueous medium.

[9] The dispersion liquid according to any one of [1] to [8], wherein the tetrafluoroethylene-based polymer is a polymer comprising a tetrafluoroethylene-based unit, and a perfluoro (alkyl vinyl ether) -based unit, a hexafluoropropylene-based unit, or a fluoroalkylethylene-based unit.

[10] The dispersion liquid according to [9], wherein the tetrafluoroethylene-based polymer further comprises a unit having a functional group.

[11] The dispersion liquid according to any one of [1] to [10], wherein the tetrafluoroethylene-based polymer contains 99.5 mol% or more of units based on tetrafluoroethylene with respect to all units contained in the polymer.

[12] The dispersion liquid according to any one of [1] to [11], wherein the tetrafluoroethylene-based polymer contains more than 0.5 mol% of units based on a comonomer other than tetrafluoroethylene with respect to all units contained in the polymer.

[13] The dispersion liquid according to any one of [1] to [12], wherein the tetrafluoroethylene-based polymer has at least 1 functional group selected from a carbonyl group-containing group, a hydroxyl group, an epoxy group, an amide group, an amino group and an isocyanate group.

[14] A method for producing a laminate, which comprises applying the dispersion liquid described in any one of [1] to [13] to the surface of a substrate and heating the application liquid to form a resin layer containing a tetrafluoroethylene polymer, thereby obtaining a laminate in which the substrate and the resin layer are laminated in this order.

[15] A method for producing a coated woven fabric, which comprises impregnating a woven fabric with the dispersion liquid according to any one of [1] to [13], and drying the woven fabric to obtain a woven fabric coated with a tetrafluoroethylene polymer-containing resin layer.

Effects of the invention

According to the present invention, there can be provided a dispersion which is excellent in dispersion properties and resin layer-forming properties in addition to dispersibility and redispersibility and which can form a layer of a tetrafluoroethylene polymer on the surface of various substrates.

Detailed Description

The following terms have the following meanings.

"D50 of the powder" means a particle size distribution of the powder measured by a laser diffraction scattering method, and a cumulative curve obtained by taking the total volume of the powder particle group as 100%, and a point on the cumulative curve where the cumulative volume reaches 50% (volume-based cumulative 50% diameter).

"D90 of the powder" means a particle size distribution of the powder measured by a laser diffraction scattering method, and a cumulative curve obtained by taking the total volume of the powder particle clusters as 100%, and a particle diameter at a point on the cumulative curve where the cumulative volume reaches 90% (cumulative 90% diameter on volume basis).

"melt viscosity of polymer" means a value measured by holding a polymer sample (2g) preheated at a measurement temperature for 5 minutes under a load of 0.7MPa at the measurement temperature using a flow tester and a 2. phi. -8L mold based on ASTM D1238.

The "melting point (melting temperature) of the polymer" means a temperature corresponding to the maximum value of a melting peak measured by a Differential Scanning Calorimetry (DSC) method.

The "viscosity" is a value measured at room temperature (25 ℃) and 30rpm using a B-type viscometer. The measurement was repeated 3 times, and the average of the 3 measurements was taken.

"thixotropic ratio" means the viscosity η of a liquid composition measured at a rotation speed of 30rpm₁Divided by the viscosity eta of the liquid composition measured at a rotation speed of 60rpm₂The calculated value (η)₁/η₂)。

"ten point roughness average (Rz)_JIS) "is JISB 0601: 2013, attached JA.

The "unit" in the polymer is a general term for an atomic group derived from the monomer 1 molecule and formed by polymerization of the monomer, and an atomic group obtainable by chemical conversion of a part of the atomic group. The "unit" in the polymer may be a radical formed directly from a monomer by polymerization, or a radical in which a part of the structure is converted by treating a polymer obtained by polymerization in a predetermined method.

The dispersion liquid of the present invention is a dispersion liquid which contains a liquid dispersion medium, a powder of a tetrafluoroethylene polymer (hereinafter also referred to as a "TFE-based polymer") and a dispersant, and in which the powder is dispersed in the liquid dispersion medium. The dispersant is a compound having a fluorine-containing moiety and a secondary or tertiary hydroxyl moiety (hereinafter also referred to as "a predetermined dispersant").

The dispersion liquid of the present invention has low chemical activity, excellent dispersibility such as viscosity and color tone, and excellent resin layer-forming properties such as a thixotropic ratio, adhesiveness, transparency, defoaming property, and resistance to powder falling, in addition to dispersibility and redispersibility. The reason for this is as follows: the secondary or tertiary hydroxyl group of a given dispersant has lower activity (reactivity, acidity, etc.) and polarity, and lower hydrophilicity than dispersants having a primary hydroxyl group. That is, the interaction with the hydrophilic component is considered to be reduced in the predetermined dispersant as compared with the conventional dispersant, but the interaction with the TFE-based polymer is considered to be relatively enhanced. As a result, it is considered that a dispersion liquid having low chemical activity and excellent dispersion properties and resin layer formation properties can be obtained. This effect is also exhibited remarkably in a preferred embodiment of the present invention described later.

The D50 of the powder of the present invention is preferably 0.05 to 6 μm, and particularly preferably 0.1 to 3 μm. In this case, the powder flowability and dispersibility are further improved, and the resin layer or layer (hereinafter also referred to as "F layer") formed from the dispersion liquid of the present invention has more excellent surface smoothness. D90 of the powder is preferably 8 μm or less, and particularly preferably 1.5 to 5 μm. In this case, the dispersibility of the powder and the homogeneity of the F layer are excellent.

The sparse packing volume density and the dense packing volume density of the powder are preferably 0.08-0.5 g/mL and 0.1-0.8 g/mL in sequence.

The powder in the present invention is a powder containing a TFE-based polymer as a main component. The content of the TFE polymer in the powder is preferably 80% by mass or more, particularly preferably 100% by mass. Examples of other resins that may be contained in the powder include: aromatic polyesters, polyamideimides, thermoplastic polyimides, polyphenylene ethers (plaintext: ポリフェニレンエーテル), polyphenylene ethers (plaintext: ポリフェニレンオキシド), and the like.

The secondary hydroxyl moiety or tertiary hydroxyl moiety of the dispersant is preferably-CH (CH)₃)OH、-CH(CH₂CH₃) OH or-C (CH)₃)₂OH, particularly preferably-CH (CH)₃)OH。

The fluorine-containing site of the predetermined dispersant is preferably a polyfluoroalkyl group, a polyfluoroalkyl group containing an etheric oxygen atom, or a polyfluoroalkyl group, and a polyfluoroalkyl group is particularly preferable. The number of carbon atoms in the fluorine-containing moiety is preferably 4 to 16, particularly preferably 4 to 12.

The secondary hydroxyl group site or the tertiary hydroxyl group site of the predetermined dispersant may be directly bonded to the fluorine-containing site or may be bonded to the fluorine-containing site through a linker, preferably through a linker. In this case, not only the defoaming property of the dispersion liquid of the present invention is further improved, but also the powder falling off at the time of forming the F layer is more easily suppressed.

The linking group is preferably a polyoxyalkylene group.

The defined dispersant is preferably of the formula R^F(OQ¹)_m-(OQ²)_nA compound represented by OH.

R^FRepresents a polyfluoroalkyl group or an ether oxygen atomPolyfluoroalkyl group of (1), preferably F (CF)₂)₄CH₂-、F(CF₂)₆CH₂-、F(CF₂)₄CH₂CH₂-、F(CF₂)₆CH₂CH₂Or formula R^F1(CF₂O)_f1·(CF₂CF₂O)_f2CF₂CH₂Group (R) represented by O-^F1Is CF₃-or CF₃CF₂-, F1 and F2 are each independently an integer of 0 to 8 and the sum of F1 and F2 is 4 to 8), particularly preferably F (CF)₂)₄CH₂-、F(CF₂)₆CH₂-、F(CF₂)₄CH₂CH₂-or F (CF)₂)₆CH₂CH₂-。

Q¹Represents a methylene group (-CH)₂-) dimethylene (-CH)₂CH₂-) trimethylene group (-CH₂CH₂CH₂-) or tetramethylene (-CH)₂CH₂CH₂CH₂-, preferably dimethylene.

Q²Represents 1, 2-propylene (-CH)₂CH(CH₃) -) propylene (-CH (CH)₂CH₃) -) or isopropylidene (-C (CH)₃)₂-, preferably 1, 2-propylene. However, in the case of 1, 2-propylene, the hydroxyl group is bonded to a secondary carbon atom.

m is an integer of 4 to 16, preferably an integer of 4 to 10.

n is an integer of 1 to 3, preferably 1.

R in the compound^F、Q¹、Q²When m and n are each in a preferred range, not only the defoaming property of the dispersion liquid is particularly improved, but also the dusting of powder is more easily suppressed when a laminate or a coated woven fabric described later is produced from the dispersion liquid of the present invention.

Specific examples of the predetermined dispersant include:

F(CF₂)₆CH₂(OCH₂CH₂)₇-(OCH₂CH(CH₃))OH、

F(CF₂)₆CH₂(OCH₂CH₂)₁₂-(OCH₂CH(CH₃))OH、

F(CF₂)₆CH₂CH₂(OCH₂CH₂)₇-(OCH₂CH(CH₃))OH、

F(CF₂)₆CH₂CH₂(OCH₂CH₂)₁₂-(OCH₂CH(CH₃))OH、

F(CF₂)₄CH₂CH₂(OCH₂CH₂)₇-(OCH₂CH(CH₃))OH、

F(CF₂)₄CH₂CH₂(OCH₂CH₂)₁₂-(OCH₂CH(CH₃))OH。

the dispersant is available as a commercially available product (FluowetN 083, FluowetN050, manufactured by Onga corporation (Providence: アークロマ Co., Ltd.).

The liquid dispersion medium in the present invention is a compound which is liquid at 25 ℃ and has a function of dispersing the powder of the present invention, and may be an aqueous medium or a nonaqueous medium.

The compound of the liquid dispersion medium is preferably water, a nitrogen-containing compound, a sulfur-containing compound, an ester, a ketone, a glycol ether or other polar compound, and particularly preferably water. In the case of a polar compound, although the interaction between the secondary hydroxyl group site or the tertiary hydroxyl group site contained in a predetermined dispersant and the polar compound is reduced, the interaction between the compound and the TFE-based polymer tends to be relatively enhanced, and the dispersion properties of the dispersion liquid and the resin layer-forming properties tend to be further improved. The liquid dispersion medium may be used alone in 1 kind, or in combination of 2 or more kinds.

Specific examples of the compound as the liquid dispersion medium include: water, methanol, ethanol, isopropanol, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethyl ether, dioxane, ethyl lactate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isopropyl ketone, cyclopentanone, cyclohexanone, ethylene glycol monoisopropyl ether, cellosolve (methyl cellosolve, ethyl cellosolve, etc.).

The liquid dispersion medium is preferably an aqueous medium. The aqueous medium is a dispersion medium containing water as a main component, and may be composed of water alone or a mixed medium of water and a water-soluble organic dispersion medium.

The TFE-based polymer in the present invention is a polymer including a Tetrafluoroethylene (TFE) -based unit (hereinafter also referred to as a "TFE unit").

The TFE-based polymers are preferably: a homopolymer substantially composed of a TFE unit (hereinafter also referred to as "PTFE"), a copolymer comprising a TFE unit and a unit based on perfluoro (alkyl vinyl ether) (hereinafter also referred to as "PAVE unit"), a copolymer comprising a TFE unit and a unit based on Hexafluoropropylene (HFP) (hereinafter also referred to as "HFP unit"), or a copolymer comprising a TFE unit and a unit based on fluoroalkyl ethylene (hereinafter also referred to as "FAE") (hereinafter also referred to as "FAE unit").

PTFE also includes polymers containing units other than TFE units in very small amounts, and low molecular weight PTFE. The polymer preferably contains more than 99.5 mol% of TFE units, and particularly preferably contains more than 99.9 mol% of TFE units, relative to all units contained in the polymer. The melt viscosity of the polymer at 380 ℃ is preferably 1X 10²～1×10⁸Pa · s, particularly preferably 1X 10³～1×10⁶Pa·s。

The low-molecular-weight PTFE may be PTFE obtained by irradiating high-molecular-weight PTFE with radiation (polymers described in international publication nos. 2018/026012, 2018/026017, and the like), PTFE obtained by using a chain transfer agent in producing PTFE by polymerizing TFE (polymers described in japanese patent laid-open nos. 2009-1745, 2010/114033, 2015-232082, and the like), or PTFE having a core-shell structure composed of a core portion and a shell portion and having a low molecular weight in only the shell portion (polymers described in japanese patent laid-open nos. 2005-527652, 2016/170918, jp-h 09-087334, and the like).

The standard specific gravity (specific gravity measured in accordance with ASTM D4895-04) of the low molecular weight PTFE is preferably 2.14 to 2.22, more preferably 2.16 to 2.20.

Polymers containing units other than TFE units are also included in the TFE unit-containing polymers. The polymer preferably contains more than 0.5 mol%, relative to all units of the polymer, of units based on monomers other than TFE units. The units other than TFE are preferably PAVE units, HFP units, FAE units, or units having a functional group described later.

The TFE unit-containing polymer preferably has at least 1 functional group selected from the group consisting of carbonyl-containing groups, hydroxyl groups, epoxy groups, oxetanyl groups, amino groups, nitro groups, and isocyanate groups. When the TFE-based polymer has the functional group, the interaction between the secondary hydroxyl group site or the tertiary hydroxyl group site contained in the predetermined dispersant and the TFE-based polymer is easily enhanced, and the dispersion properties of the dispersion liquid and the resin layer formation properties are more easily improved.

The functional group may be contained in a unit constituting the TFE-based polymer, may be contained in a terminal group of the main chain of the polymer, or may be introduced into the TFE-based polymer by plasma treatment or the like. Examples of the TFE-based polymer having the functional group at the end group of the polymer main chain include: TFE polymers having a functional group as an end group derived from a polymerization initiator, a chain transfer agent or the like.

The above functional group is preferably a hydroxyl group or a carbonyl group, more preferably a carbonyl group, particularly preferably a carbonate group, a carboxyl group, a haloformyl group, an alkoxycarbonyl group or an acid anhydride residue, and most preferably a carboxyl group or an acid anhydride residue.

The TFE-based polymer preferably comprises TFE units; PAVE unit, HFP unit, or FAE unit; more preferably a polymer comprising TFE units; PAVE unit, HFP unit, or FAE unit; a unit having a functional group; the polymer of (1).

The units having a functional group are preferably units based on monomers having a functional group.

As the monomer having a functional group, a monomer having a hydroxyl group or a carbonyl group is preferable, and a cyclic monomer having an acid anhydride residue is particularly preferable.

Examples of the cyclic monomer include: itaconic anhydride, citraconic anhydride, 5-norbornene-2, 3-dicarboxylic anhydride (also referred to as nadic anhydride; hereinafter, also referred to as "NAH"), maleic anhydride, preferably NAH.

As PAVE, there may be mentioned: CF (compact flash)₂＝CFOCF₃、CF₂＝CFOCF₂CF₃、CF₂＝CFOCF₂CF₂CF₃(hereinafter also referred to as "PPVE"), CF₂＝CFOCF₂CF₂CF₂CF₃、CF₂＝CFO(CF₂)₈F, etc., preferably PPVE.

As FAEs, there may be mentioned: CH (CH)₂＝CH(CF₂)₂F、CH₂＝CH(CF₂)₃F、CH₂＝CH(CF₂)₄F、CH₂＝CF(CF₂)₃H、CH₂＝CF(CF₂)₄H。

In this case, the TFE unit, PAVE unit, HFP unit, FAE unit, and the unit having a functional group contained in the polymer are preferably 90 to 99 mol%, 0.5 to 9.97 mol%, and 0.01 to 3 mol%, respectively, in this order, based on all the units contained in the polymer.

In this case, the TFE polymer preferably has a melting point of 250 to 380 ℃ and particularly preferably 280 to 350 ℃.

Specific examples of the TFE polymer include the polymers described in International publication No. 2018/16644.

The content of the TFE polymer in the dispersion liquid of the present invention is preferably 20 to 70% by mass, and particularly preferably 30 to 60% by mass.

The content of the predetermined dispersant in the dispersion liquid of the present invention is preferably 0.1 to 10% by mass, and particularly preferably 1 to 5% by mass.

The content of the liquid dispersion medium in the dispersion liquid of the present invention is preferably 15 to 75 mass%, particularly preferably 25 to 60 mass%.

When the liquid dispersion medium is an aqueous medium, the content of water in the liquid dispersion medium is preferably 95% by mass or more, more preferably 99% by mass or more, and particularly preferably 100% by mass.

The dispersion liquid of the present invention may contain other materials than the liquid dispersion medium, the powder of the TFE-based polymer, and the prescribed dispersant.

As other materials, there may be mentioned: thixotropy imparting agents, fillers, antifoaming agents, dehydrating agents, plasticizers, weather resisting agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, mold release agents, surface treating agents, viscosity modifiers, flame retardants.

The other materials may or may not be soluble in the dispersion.

As other materials, there may be mentioned: thermosetting resins, hot-melt resins, reactive silicone silanes, carbon black.

As the thermosetting resin, there can be mentioned: epoxy resins, thermosetting polyimides, polyamic acids, thermosetting acrylic resins, phenol resins, thermosetting polyester resins, thermosetting polyolefin resins, thermosetting modified polyphenylene ether resins, bismaleimide resins, polyfunctional cyanate ester resins, polyfunctional maleimide-cyanate ester resins, polyfunctional maleimide resins, vinyl ester resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-urea copolycondensation resins.

Examples of the hot-melt resin include: polyester resins, polyolefin resins, styrene resins, polycarbonates, thermoplastic polyimides, polyarylates, polysulfones, polyarylsulfones, aromatic polyamides, aromatic polyetheramides, polyphenylene sulfides, polyaryletherketones, polyamideimides, liquid crystalline polyesters, polyphenylene oxides, and the like.

As other materials, inorganic fillers may be cited, more specifically, the following may be cited: hollow inorganic microspheres such as glass microspheres and ceramic microspheres.

The glass microspheres preferably comprise silica glass or borosilicate glass.

The ceramic microspheres preferably comprise barium titanate, particularly preferably barium titanate doped with neodymium oxide or zinc oxide.

The hollow inorganic microspheres are preferably spheres having a dielectric constant of 4 or more and a thermal coefficient of dielectric constant of 150 ppm/DEG C or less at 20 to 50 ℃.

The hollow inorganic microspheres may be non-porous or porous.

The hollow inorganic microspheres may be crystalline or amorphous.

The preferred density of the hollow inorganic microspheres is 0.1-0.8 g/cm³The average particle diameter is 5 to 100 μm.

The hollow inorganic microspheres are preferably coated with a silane coupling agent, a zirconate coupling agent, or a titanate coupling agent to have hydrophobicity.

Examples of the silane coupling agent include: phenyltrimethoxysilane, phenyltriethoxysilane, (3,3, 3-trifluoropropyl) trimethoxysilane, (tridecafluoro-1, 1,2, 2-tetrahydrooctyl) triethoxysilane, and (heptadecafluoro-1, 1,2, 2-tetrahydrodecyl) triethoxysilane.

Examples of the zirconate coupling agent include: neopentyl (diallyl) oxytris (dioctyl) pyrophosphate zirconate, neopentyl (diallyl) oxytris (N-ethyldiamino) ethylzirconate.

Examples of the titanate coupling agent include: neopentyl (diallyl) oxytrimethyldecanoyl titanate, neopentyl (diallyl) oxytridodecyl benzenesulfonyl titanate, neopentyl (diallyl) oxytrioctyl phosphate titanate.

The resin-coated metal foil in which the resin layer is formed by applying the dispersion liquid of the present invention containing hollow inorganic microspheres onto the surface of a copper foil and removing the liquid dispersion medium is suitable as a printed board material exhibiting a low dielectric constant thermal coefficient.

The viscosity of the dispersion of the present invention is preferably 1 to 1000 mPas, more preferably 5 to 500 mPas, and particularly preferably 10 to 100 mPas. Within this range, the dispersibility and coatability of the dispersion liquid are more easily balanced.

Thixotropic ratio (. eta.) of the dispersion of the invention₁/η₂) Preferably 1 to 2.2. In this range, the dispersion is divided intoDispersibility and coatability are more easily balanced.

The dispersion liquid of the present invention can be produced by mixing a liquid dispersion medium, a powder of a TFE-based polymer, and a predetermined dispersant, and is preferably produced by mixing a liquid dispersion medium, a predetermined dispersant, and a powder of a TFE-based polymer.

In the mixing, it is preferable to perform a dispersion treatment using a homomixer or homogenizer to improve the dispersion state. When the dispersion of the present invention stored at 0 to 40 ℃ is used, it is preferable to perform the dispersion treatment and then use it.

The dispersion of the present invention is excellent in dispersion properties and resin layer-forming properties, and can be used as a coating agent for forming a layer (resin layer).

The dispersion of the present invention is further characterized by the following points: not only can powder falling of the predetermined dispersant be suppressed by heating at the time of forming a layer (resin layer), but also the layer (resin layer) can be easily thermally decomposed and eliminated, and a layer (resin layer) with a small amount of the predetermined dispersant remaining can be obtained.

The residual amount of the predetermined dispersant in the F layer is preferably 25 mass% or less, particularly preferably 5 mass% or less, based on the amount of the predetermined dispersant contained in the dispersion used.

The present invention provides a method for producing a laminate, comprising applying the dispersion of the present invention to the surface of a substrate and heating the applied dispersion to form a TFE polymer-containing resin layer (F layer), and laminating the substrate and the resin layer in this order to form a laminate.

In the production method of the present invention, the resin layer may be formed on at least one surface of the substrate, and the resin layer may be formed on only one surface of the substrate or may be formed on both surfaces of the substrate.

Examples of the method for applying the dispersion include: spray coating, roll coating, spin coating, gravure coating, microgravure coating, gravure offset coating, knife coating, kiss roll coating (japanese: キスコート method), bar coating, die coating, jet meyer bar coating (japanese: ファウンテンメイヤーバー method), slit die coating.

The resin layer is preferably formed by heating, and the substrate coated with the dispersion liquid of the present invention is preferably heated to a temperature (temperature range of 100 to 300 ℃) at which the liquid dispersion medium volatilizes, and further heated to a temperature range (300 to 400 ℃) at which the TFE-based polymer melts or is fired.

Examples of the heating method include: a method using an oven, a method using a through-air drying oven, a method of irradiating heat rays (infrared rays), and the like.

The atmosphere during heating may be either normal pressure or reduced pressure. The atmosphere may be any of an oxidizing gas (oxygen, etc.), a reducing gas (hydrogen, etc.), and an inert gas (helium, neon, argon, nitrogen, etc.).

The heating time of the substrate is usually 0.5 to 30 minutes.

The thickness of the resin layer is preferably 30 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less. The upper limit of the thickness of the resin layer is 0.1. mu.m, preferably 2 μm.

The peel strength between the substrate and the resin layer is preferably more than 12N/cm, and particularly preferably 15N/cm or more. The upper limit of the peel strength is usually 100N/cm.

The substrate may be any of a metal substrate such as copper, aluminum, or iron, a glass substrate, a resin substrate, a silicon substrate, or a ceramic substrate.

The shape of the substrate may be any of a planar shape, a curved shape, and an uneven shape, and may be any of a foil shape, a plate shape, a film shape, and a fiber shape.

Specific examples of the laminate obtained by the production method of the present invention include: the base material is a metal foil and a metal foil with resin having a metal foil and a resin layer in this order.

An adhesive layer may be provided between the metal foil and the resin layer, but the adhesive layer may not be provided because the resin layer formed from the dispersion liquid of the present invention has excellent adhesion.

Preferred embodiments of the metal foil include: copper foil such as rolled copper foil and electrolytic copper foil. In the metal foil with resin, the thickness of the metal foil is preferably 3 to 18 μm, and the thickness of the resin layer is preferably 1 to 50 μm.

When a patterned circuit is formed on a metal foil, the resin-coated metal foil can be used as a printed wiring board having a resin layer as an insulating resin layer.

In the case of forming a through hole in a printed wiring board having pattern circuits on both sides of an electrical insulating layer, NC punching, carbon dioxide laser irradiation, or UV-YAG laser irradiation may be used. For UV-YAG laser irradiation, a 3 rd harmonic (wavelength of 355nm) or a 4 th harmonic (wavelength of 266nm) may be used.

In the resin-coated metal foil of this case, an ultraviolet absorber, a pigment (aluminum oxide, zinc oxide, titanium oxide, or the like), a curing agent (triallyl isocyanurate, or the like), or the like may be further blended in the dispersion liquid of the present invention, or the heating temperature at the time of forming the resin layer may be adjusted.

Further, a plating layer may be formed on an inner wall surface of the formed through-hole. The plating layer may be formed by any of etching treatment using sodium metal, treatment using a permanganate solution, and plasma treatment, or may be formed by treatment using a permanganate solution or plasma treatment.

Specific examples of the laminate obtained by the production method of the present invention include: the substrate is a polyimide film having a resin layer formed from the dispersion liquid of the present invention on at least one surface of the polyimide film surface.

An adhesive layer may be separately provided between the polyimide film and the resin layer, but the adhesive layer may not be provided because the resin layer formed from the dispersion liquid of the present invention has excellent adhesion.

Preferred embodiments of the polyimide film include: a film of a polymer of an acid dianhydride comprising 2,2',3,3' -or 3,3',4,4' -biphenyltetracarboxylic dianhydride and a diamine comprising p-phenylenediamine. Specific examples of the polyimide film include ApicalTypeAF (manufactured by bellied north america).

The mass of the laminate is preferably 23.5g/m²The ring stiffness is preferably 0.45g/cm or more.

In the laminate, the thickness of the resin layer is preferably 1 to 200 μm, particularly preferably 5 to 20 μm. In the laminate, the thickness of the polyimide film is preferably 5 to 150 μm.

The laminate is excellent in electrical insulation, abrasion resistance, hydrolysis resistance and the like, and can be used as an electrical insulating tape, a cable or a packaging material for electric wires, and is suitable as a material for electric wires or cables for aerospace or electric automobiles.

The laminate obtained by the production method of the present invention may further have another material laminated on the resin layer.

When the surface of the resin layer is pressure-bonded to the 2 nd substrate, a composite laminate can be obtained in which the 1 st substrate (which represents a substrate in the method for producing a laminate of the present invention, hereinafter the same), the resin layer, and the 2 nd substrate are laminated in this order.

As the 2 nd substrate, there can be mentioned: metal substrates such as copper, aluminum, and iron, glass substrates, resin substrates, silicon substrates, and ceramic substrates.

The shape of the 2 nd substrate may be any of a planar shape, a curved surface shape, and an uneven shape.

The shape of the 2 nd substrate may be any of foil, plate, film and fiber.

Specific examples of the 2 nd base material include: a heat-resistant resin base material, a prepreg that is a precursor of a fiber-reinforced resin plate, and the like.

The prepreg is a sheet-like substrate obtained by impregnating a substrate (e.g., chopped jute, woven fabric, etc.) of reinforcing fibers (e.g., glass fibers, carbon fibers, etc.) with a resin (e.g., the above-described thermosetting resin, thermoplastic resin, etc.).

The heat-resistant resin substrate is preferably a film containing a heat-resistant resin. The heat-resistant resin substrate may be a single layer or a plurality of layers. Examples of the heat-resistant resin include: polyimide, polyarylate, polysulfone, polyarylsulfone, aromatic polyamide, aromatic polyether amide, polyphenylene sulfide, polyaryl ether ketone, polyamide imide, liquid crystalline polyester, PTFE, and the like.

As a method of pressure-bonding the surface of the resin layer of the laminate to the 2 nd substrate, a thermal compression bonding method is exemplified. The press-bonding temperature in the hot press-bonding method when the 2 nd base material is a prepreg is preferably 120 to 300 ℃. The thermocompression bonding temperature when the 2 nd base material is a heat-resistant resin base material is preferably 300 to 400 ℃.

The thermocompression bonding is particularly preferably performed under a vacuum of 20kPa or less.

The pressure in the thermocompression bonding is preferably 0.2 to 10 MPa.

The 2 nd resin layer is formed by applying a liquid layer forming material for forming the 2 nd resin layer on the surface of the resin layer of the laminate obtained by the production method of the present invention, and a composite laminate in which the 1 st substrate, the resin layer, and the 2 nd resin layer are laminated in this order can also be obtained.

The liquid layer-forming material is not particularly limited, and the dispersion liquid of the present invention can be used.

The method for forming the 2 nd resin layer may be appropriately determined depending on the properties of the liquid layer-forming material used. For example, when the layer forming material is the dispersion liquid of the present invention, the 2 nd resin layer may be formed under the same conditions as the resin layer forming method in the method for producing a laminate of the present invention. That is, if the layer forming material is the dispersion liquid of the present invention, it is easy to form a resin layer having a larger thickness by making the resin layer into a plurality of layers.

The composite laminate obtained by the above-described production method may be in the form of a metal foil with resin or an insulating coating.

When the base material of the laminate obtained by the production method of the present invention is removed, a thin film containing a TFE-based polymer can be obtained.

Examples of the method for removing the base material of the laminate include: a method of peeling the substrate from the laminate to remove it, and a method of dissolving the substrate from the laminate to remove it. For example, when the base material of the laminate is a copper foil, the base material is dissolved and removed by contacting hydrochloric acid on the base material surface of the laminate, and a thin film is easily obtained.

The film thickness of the film of the present invention is preferably 30 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less. The lower limit of the film thickness of the thin film is preferably 1 μm, and particularly preferably 4 μm.

The present invention provides a method for producing a coated woven fabric, which comprises impregnating a woven fabric with the dispersion of the present invention, and drying the woven fabric to obtain a woven fabric coated with a TFE-based resin layer.

The woven fabric is not particularly limited as long as it is a heat-resistant woven fabric that can resist drying, and is preferably a glass fiber woven fabric, a carbon fiber woven fabric, an aramid fiber woven fabric, or a metal fiber woven fabric, more preferably a glass fiber woven fabric or a carbon fiber woven fabric, and particularly preferably a plain-woven glass fiber woven fabric composed of E glass yarn for electrical insulation specified in JISR3410 from the viewpoint of electrical insulation.

The woven fabric may be treated with a silane coupling agent from the viewpoint of improving adhesion to the resin layer. However, since the resin layer formed from the dispersion of the present invention has excellent adhesiveness, the woven fabric may not be treated with a silane coupling agent.

The total content of TFE polymers in the coated woven fabric is preferably 30 to 80% by mass or more.

Examples of the method for impregnating a woven fabric with the dispersion of the present invention include: a method of immersing a woven fabric in the dispersion, and a method of applying the dispersion to a woven fabric.

The number of dipping times in the former method and the number of coating times in the latter method may be 1 or 2 or more, respectively.

In the method for producing a coated woven fabric of the present invention, a coated woven fabric having a high polymer content and a woven fabric firmly bonded to a polymer can be obtained even when the number of dipping or coating is small.

The method of drying the woven fabric can be suitably determined depending on the kind of the compound of the liquid dispersion medium contained in the dispersion liquid, and for example, in the case where the liquid dispersion medium is water, a method of passing the woven fabric through a ventilation drying oven in an atmosphere of 80 to 120 ℃ can be cited.

The polymer may be fired while the fabric is being dried. The method of firing the polymer can be suitably determined depending on the type of the TFE polymer, and for example, a method of passing the woven fabric through a ventilation drying furnace in an atmosphere of 300 to 400 ℃. Further, the drying of the woven fabric and the firing of the polymer may be performed in one step.

The coated woven fabric obtained by the production method of the present invention is excellent in the following characteristics: high adhesion between the resin layer and the woven fabric, high surface smoothness, less strain, and the like. For example, a resin-attached metal foil obtained by thermally pressing the coated woven fabric and the metal foil has high peel strength and is not easily warped, and therefore, is suitable as a printed board material.

In the method for producing a coated woven fabric of the present invention, a coated woven fabric layer containing a TFE-based polymer and a woven fabric can be formed by applying a woven fabric impregnated with the dispersion of the present invention to the surface of a substrate, heating and drying the coated woven fabric layer, and a laminate in which the substrate and the coated woven fabric layer are laminated in this order can be produced.

The form is not particularly limited, and if a woven fabric containing the dispersion is applied to a part of the inner wall surface of a molded article such as a tank, a pipe, a container, etc., and the molded article is heated while being rotated, a coating woven fabric layer can be formed on the entire inner wall surface of the molded article. Therefore, the method for producing a coated woven fabric of the present invention can also be used as a method for lining the inner wall surface of a molded article such as a tank, a duct, a container, or the like.

Further, by mixing the dispersion of the present invention with a conventional aqueous dispersion of a TFE-based polymer, the physical properties of the resin layer of the aqueous dispersion can be improved. For example, a resin layer formed from a dispersion obtained by mixing the dispersion of the present invention with the aqueous dispersion is superior in crack resistance to a resin layer formed from the aqueous dispersion.

In this case, the TFE-based polymer in the dispersion liquid of the present invention is preferably a TFE-based polymer having at least 1 functional group selected from a carbonyl group-containing group, a hydroxyl group, an epoxy group, an amide group, an amino group, and an isocyanate group. In addition, the mass ratio of the TFE-based polymer contained in the dispersion liquid of the present invention to the TFE-based polymer contained in the conventional aqueous dispersion of the TFE-based polymer is preferably 1.0 or more, preferably 2.0 or more, and particularly preferably 4.0 or more at the time of mixing. The upper limit of the mass ratio is usually 10.

Examples

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

The various measurement methods are shown below.

< D50 and D90 > -of resin powder

The polymer powder was dispersed in water, and the dispersion was measured by a laser diffraction scattering particle size distribution measuring device (LA-920, horiba, Ltd.).

< arithmetic average roughness (Ra) of layer surface >

The surface of the layer was analyzed under the following measurement conditions using an atomic force microscope (Oxford instruments Co., Ltd.) to obtain a layer surface having a thickness of 1 μm²Ra of the range.

(measurement conditions)

And (3) probe: AC160TS-C3 (tip R < 7nm, spring constant 26N/m)

Measurement mode: AC-Air

Scanning rate: 1Hz

< peel strength of laminate >

The laminate cut into a rectangular shape (length 100mm, width 10mm) was fixed at a position of 50mm from one end in the longitudinal direction, and was peeled at 90 ° from the one end in the longitudinal direction at a stretching speed of 50 mm/min, and the maximum load applied at the time of peeling was taken as the peel strength (N/cm).

< evaluation of Transmission loss of double-sided copper-clad laminate >

A transmission line was formed on a copper foil of a double-sided copper-clad laminate to be used as a printed circuit board, and the signal transmission loss was measured.

As a measurement system, a 28GHz signal was processed by a microwave network analyzer and measured by a high-frequency contact probe (250 μm pitch) of GSG. The coplanar waveguide with the back conductor is used as a transmission line formed on a printed substrate.

The characteristic impedance of the line is 50 Ω.

Gold flash plating is performed on the surface of copper, which is a conductor of a printed substrate.

The correction method uses TRL correction (through reflection line correction).

The length of the line was 50mm, and the transmission loss per unit length was measured. As the index, an "S-parameter" (hereinafter, also referred to as an S-value) which is one of circuit network parameters used for representing the characteristics of the high-frequency electronic circuit and the high-frequency electronic component is used. As for the S value, the closer to 0 the value thereof means the smaller the transmission loss. The evaluation of the transmission loss in the case where the S value is more than-1.6 is regarded as "good", and the evaluation of the transmission loss in the case where it is less than-1.6 is regarded as "poor".

The materials used are as follows.

[ TFE polymers ]

Polymer 1: a copolymer comprising TFE-based units, NAH-based units, and PPVE-based units in this order of 97.9 mol%, 0.1 mol%, and 2.0 mol% (melting point 300 ℃).

[ dispersing agent ]

Dispersant 1: f (CF)₂)₆CH₂CH₂O(CH₂CH₂O)₇CH₂CH(CH₃)OH

Dispersant 2: f (CF)₂)₆CH₂CH₂O(CH₂CH₂O)₁₂CH₂CH(CH₃)OH

Dispersant 3: f (CF)₂)₆CH₂CH₂O(CH₂CH₂O)₇CH₂CH₂OH

Example 1 preparation of Dispersion

[ examples 1-1]

Powder 1 (D50: 2.6 μm, D90: 7.1 μm) of Polymer 1 was obtained by the method described in paragraph [0123] of International publication No. 2016/017801.

150g of powder 1, 5g of dispersant 1 and 335g of water were charged into a jar of a horizontal ball mill and dispersed with zirconium beads having a diameter of 15mm to obtain dispersion 1 of powder 1 in which powder of polymer 1 was dispersed. The viscosity of the dispersion 1 was 19 mPas. The viscosities measured at 6rpm and 60rpm were 13 mPas and 23 mPas in this order, and the thixotropic ratio was 1.2.

[ examples 1-2]

A dispersion liquid 2 was obtained in the same manner as in example 1-1 except that the dispersant 1 was changed to the dispersant 2. The viscosity of the dispersion 2 was 16 mPas. The viscosities measured at 6rpm and 60rpm were 13 mPas and 19 mPas in this order, and the thixotropic ratio was 1.2. Further, the dispersion 2 was more likely to foam than the dispersion 1.

[ examples 1 to 3]

An attempt was made to prepare a dispersion liquid in the same manner as in example 1-1 except that the dispersant 1 was changed to the dispersant 3, but the dispersion liquid became viscous remarkably, and a dispersion liquid which could resist coating could not be obtained.

Example 2 production of laminate

[ example 2-1]

The dispersion 1 was applied to a copper foil (electrolytic copper foil manufactured by Futian Metal foil powder industries, CF-T4X-SV. Rzjis having a ten-point surface roughness of 1.2 μm), and dried at 100 ℃ for 15 minutes in a nitrogen atmosphere to form a dry film on the surface of the copper foil. Further, no powder was found to fall off from the dried film at the end faces of the copper foil.

Further, the mixture was heated at 350 ℃ for 15 minutes and gradually cooled to obtain a laminate (resin-coated copper foil) in which a layer of the polymer 1 (film thickness: 7 μm) and a copper foil were laminated together. The residual amount of the dispersant in the layer of polymer 1, which was quantified by TG-MS, was 4% by mass.

Using a plasma processing apparatus (NORDSON MARCH, AP-1000), the RF output power: 300W, inter-electrode gap: 2 inches, gas introduction: argon gas and introduced gas amount: 50cm³Minute, pressure: 13Pa, treatment time: the laminate was subjected to plasma treatment on the polymer 1 layer side for 1 minute. Ra of the surface of the polymer 1 layer after the plasma treatment was 8 nm.

Then, an FR-4 sheet (manufactured by Hitachi chemical Co., Ltd., reinforcing fiber: glass fiber, matrix resin: epoxy resin, product name: GEA-67N) as a prepreg was stacked on the surface of the layer of the polymer 1 at 0.2t (HAN), and the thickness: 0.2mm), vacuum hot pressing (temperature: 185 ℃ and pressure: 3.0MPa, time: 60 minutes), a prepreg, a layer of polymer 1, and a copper foil were laminated in this order to obtain a laminate (single-sided copper-clad laminate). The peel strength of the laminate was 9N/cm.

A laminate is provided on each surface of an FR-4 sheet so that the outermost layer is made of a copper foil, and the laminate is pressed at a pressing temperature: 185 ℃ and the pressure: 3.0MPa, pressing time: and carrying out vacuum hot pressing for 60 minutes to obtain the double-sided copper-clad laminate. The transmission loss was evaluated to be "good".

[ examples 2-2]

The same procedure was followed, except that the dispersion 1 in example 2-1 was changed to the dispersion 2, except that the dispersion 2 was coated on a copper foil and dried at 100 ℃ for 15 minutes in a nitrogen atmosphere to form a dried film on the surface of the copper foil. At this time, the powder was found to fall off from the dried film at the end of the copper foil. Further, a resin-coated copper foil, a single-sided copper-clad laminate, and a double-sided copper-clad laminate were obtained in the same manner. The residual amount of the dispersant in the layer of the polymer 1 with a resin copper foil was 23% by mass, the peel strength of the laminate was 7N/cm, and the transmission loss of the double-sided copper-clad laminate was evaluated as "x".

Example 3 production of laminate (second)

An aqueous dispersion of PTFE (product No. AD-916E, manufactured by Asahi glass company, Asahi glass Co., Ltd.) containing 50 mass% of PTFE powder (D50: 0.3 μm) was mixed with the dispersion 1 to obtain a dispersion in which the PTFE powder and the polymer 1 powder were dispersed in water and the ratio (mass ratio) of the polymer 1 to the PTFE was 1.0. In addition, immediately before mixing, the dispersion 1 was treated with a homodispersant at 3000rpm, and further treated with a homogenizer at 3000 rpm.

The obtained dispersion was applied to the surface of a stainless steel plate (thickness: 0.5mm) having a vinyl tape attached to one end thereof, and the rod was slid along one end thereof to smoothly disperse the dispersion on the surface of the stainless steel plate. The stainless steel plate was dried at 100 ℃ for 3 minutes 3 times and further heated at 380 ℃ for 10 minutes to obtain a stainless steel plate having a surface on which a polymer I-containing coating film was formed¹And PTFE, a polymer layer having a thickness inclined by the thickness of the vinyl tape attached to the end edge. The stainless steel sheet was visually checked, and no crack line was observed even in a region having a film thickness of 50 μm or more.

Possibility of industrial utilization

The dispersion of the present invention can easily form a layer of a tetrafluoroethylene polymer, and is used for the production of a printed wiring board, and is suitably used for the production of a resin-attached copper foil and a metal laminate. The dispersion of the present invention can be used for the production of molded articles such as films and impregnated articles (prepregs, etc.), and also for the production of molded articles for applications requiring mold release properties, electrical characteristics, water-and oil-repellency, chemical resistance, weather resistance, heat resistance, smoothness, abrasion resistance, and the like. The molded article obtained from the dispersion of the present invention can be used as an antenna part, a printed circuit board, an aircraft part, an automobile part, a sports equipment, a food industrial product, a paint, a cosmetic, and the like, and specifically, can be used as an insulating layer of a power module, an electric wire coating material (an aircraft electric wire or the like), an electrically insulating tape, an insulating tape for oil drilling, a material for a printed circuit board, an electrode adhesive (a lithium secondary battery, a fuel battery or the like), a copying roll, furniture, an automobile instrument panel, a cover for a household electrical appliance, a sliding member (a load bearing, a sliding shaft, a valve, a bearing, a gear, a cam, a belt conveyor, a food conveying belt or the like), a tool (a shovel, a file, a cone, a saw or the like), a boiler, a hopper, a pipe, an oven, a baking mold, a chute, a toilet.

In addition, the entire contents of the specification, claims and abstract of japanese patent application No. 2018-188252 filed on 2018, 10/3 are incorporated herein as disclosure of the present invention.