Tetrafluoroethylene-based polymer composition, binder for electrochemical device, electrode mixture, electrode, and secondary battery

Abstract

To provide a tetrafluoroethylene-based polymer composition for a binder for an electrochemical device capable of improving high-temperature cycle characteristics of the electrochemical device and also suppressing gas generation and to provide a binder for the electrochemical device, an electrode composite, an electrode, and a secondary battery, all using the same.SOLUTION: The tetrafluoroethylene polymer composition for use in a binder for an electrochemical device contains a tetrafluoroethylene polymer, which is a copolymer of tetrafluoroethylene and a monomer having a polar group, and has fibrillation ability.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a tetrafluoroethylene-based polymer composition, a binder for an electrochemical device, an electrode binder, an electrode, and a secondary battery.

Background Art

[0002] Secondary batteries such as lithium-ion secondary batteries are used in small and portable electrical and electronic devices such as notebook computers, mobile phones, smartphones, tablet computers, ultrabooks, etc. because of their high voltage, high energy density, low self-discharge, low memory effect, and ultra-lightweight. Furthermore, they are being put into practical use as a wide range of power sources from in-vehicle drive power sources for automobiles to stationary large-scale power sources. There is a demand for further higher energy density in secondary batteries, and further improvement of battery characteristics is required.

[0003] Patent Document 1 describes an energy storage device in which at least one of the cathode and the anode contains a polytetrafluoroethylene mixed binder material.

[0004] Patent Documents 2 to 6 describe the use of polytetrafluoroethylene as a binder for a battery.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] The present disclosure aims to provide a tetrafluoroethylene-based polymer composition for a binder for an electrochemical device that can improve the high-temperature cycle characteristics of the electrochemical device and can also suppress gas generation, and a binder for an electrochemical device, an electrode binder, an electrode, and a secondary battery using the same.

MEANS FOR SOLVING THE PROBLEMS

[0007] The present disclosure (1) is a tetrafluoroethylene-based polymer composition used for a binder for an electrochemical device, including a tetrafluoroethylene-based polymer that is a copolymer of tetrafluoroethylene and a monomer having a polar group, and is a tetrafluoroethylene-based polymer composition having fibrillating ability.

[0008] The present disclosure (2) is the tetrafluoroethylene-based polymer composition according to the present disclosure (1), wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine monomer having a carboxyl group, a non-fluorine monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6). CH2=CR 11 -CO-O-R 13 (10-1) (In the formula, R 11 is a hydrogen atom or an alkyl group, and R 13 is a hydrogen atom or an alkyl group.) CX2=CY(-CZ2-O-Rf-Y 3 )(5) (In the formula, X is the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.) CX2=CY(-O-Rf-Y 3 )(6) (In the formula, X is the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.)

[0009] The present disclosure (3) is the tetrafluoroethylene-based polymer composition described in the present disclosure (1) or (2) which is in powder form.

[0010] The present disclosure (4) is used as a binder for a lithium ion secondary battery and is the tetrafluoroethylene-based polymer composition described in any one of the present disclosures (1) to (3) which is in powder form.

[0011] The present disclosure (5) is a binder for an electrochemical device substantially consisting of only a tetrafluoroethylene-based polymer composition, and the tetrafluoroethylene-based polymer composition contains a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, and is a binder for an electrochemical device having fibrillation ability.

[0012] The present disclosure (6) is the binder for an electrochemical device described in the present disclosure (5) wherein the endothermic peak temperature of the tetrafluoroethylene-based polymer composition is 327 °C or higher and 350 °C or lower.

[0013] The present disclosure (7) is a binder for an electrochemical device as described in the present disclosure (5) or (6), wherein the standard specific gravity of the tetrafluoroethylene-based polymer composition is 2.280 or less.

[0014] The present disclosure (8) is a binder for an electrochemical device as described in any one of the present disclosures (5) to (7), wherein the 1.0% mass loss temperature of the tetrafluoroethylene-based polymer composition is 492 °C or less.

[0015] The present disclosure (9) is a binder for an electrochemical device as described in any one of the present disclosures (5) to (8), wherein the thermal stability index (TII) of the tetrafluoroethylene-based polymer composition is 20 or more.

[0016] The present disclosure (10) is a binder for an electrochemical device as described in any one of the present disclosures (5) to (9), wherein the tetrafluoroethylene-based polymer composition further contains a fluorine-containing compound having a hydrophilic group.

[0017] The present disclosure (11) is that the hydrophilic group is -SO3M a , -SO2M a , -OSO2M a , -PO3M a , -COOM a , -OCOM a , and -OM a (wherein M a is -H, a metal atom, -NR 2 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, and R 2 is H or an organic group.) The binder for an electrochemical device according to the present disclosure (10), which is at least one selected from the group consisting of.

[0018] The present disclosure (12) is a binder for an electrochemical device as described in any one of the present disclosures (5) to (11), wherein the tetrafluoroethylene-based polymer composition contains a compound represented by the following general formula (1). General formula (1): (H-(CF2) m-1 -COO)p M 1 (wherein m is from 4 to 20. M 1 is H, a metal atom, NR 5 4 (R 5 may be the same or different and is H or an organic group having 1 to 10 carbon atoms), imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. p is 1 or 2.)

[0019] The present disclosure (13) is a binder for an electrochemical device according to any one of the present disclosures (5) to (12), wherein the tetrafluoroethylene-based polymer composition contains a compound represented by the following general formula (2). General formula (2): (H-(CF2) n -SO3) q M 2 (wherein n is from 4 to 20. M 2 is H, a metal atom, NR 5 4 (R 5 is the same as above), imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. q is 1 or 2.)

[0020] The present disclosure (14) is a binder for an electrochemical device according to any one of the present disclosures (5) to (13), wherein the tetrafluoroethylene-based polymer composition substantially does not contain a compound represented by the following general formula (3). General formula (3): (H-(CF2)8-SO3) q M 2 (wherein M 2 is H, a metal atom, NR 5 4 (R 5 may be the same or different and is H or an organic group having 1 to 10 carbon atoms), imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. q is 1 or 2.)

[0021] The present disclosure (15) is a binder for an electrochemical device according to any one of the present disclosures (5) to (14), wherein the monomer having the polar group is a non-fluorine monomer having a polar group.

[0022] The present disclosure (16) is a binder for an electrochemical device according to any one of the present disclosures (5) to (15), wherein the monomer having the polar group is a monomer represented by the following general formula (10). General formula (10): CH2=CR 11 -L 11 -R 12 (In the formula, R 11 represents a hydrogen atom or an alkyl group. L 11 represents a single bond, -CO-O-*, -O-CO-* or -O-. * represents the bonding position with R 12 . R 12 represents a hydrogen atom, an alkyl group or a nitrile group.)

[0023] The present disclosure (17) is a binder for an electrochemical device according to any one of the present disclosures (5) to (15), wherein the monomer having the polar group is at least one selected from the group consisting of a non-fluorine monomer having a carboxyl group, a non-fluorine monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6). CH2=CR 11 -CO-O-R 13 (10-1) (In the formula, R 11 is a hydrogen atom or an alkyl group, and R 13 is a hydrogen atom or an alkyl group.) CX2=CY(-CZ2-O-Rf-Y 3 )(5) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group, Z is the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3is a hydrophilic group.) CX2=CY(-O-Rf-Y 3 )(6) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group, and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.)

[0024] The present disclosure (18) is a binder for a lithium ion secondary battery, and is a binder for an electrochemical device described in any one of the present disclosures (5) to (17) which is in powder form.)

[0025] The present disclosure (19) is a tetrafluoroethylene-based polymer composition used as a binder for an electrochemical device, and includes a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, has a fibrillated portion, and has an endothermic peak temperature of 327 °C or higher and 350 °C or lower.)

[0026] The present disclosure (20) is the tetrafluoroethylene-based polymer composition according to the present disclosure (19), wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine monomer having a carboxyl group, a non-fluorine monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6). CH2=CR 11 -CO-O-R 13 (10-1) (In the formula, R 11 is a hydrogen atom or an alkyl group, and R 13 is a hydrogen atom or an alkyl group.) CX2=CY(-CZ2-O-Rf-Y 3 )(5) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorinated alkyl group, and Z is the same or different and is -H, -F, an alkyl group or a fluorinated alkyl group. Rf is a fluorinated alkylene group having 1 to 40 carbon atoms or a fluorinated alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.) CX2=CY(-O-Rf-Y 3 )(6) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorinated alkyl group, and Rf is a fluorinated alkylene group having 1 to 40 carbon atoms or a fluorinated alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.)

[0027] The present disclosure (21) is used as a binder for a lithium ion secondary battery and is the tetrafluoroethylene-based polymer composition described in the present disclosure (19) or (20) which is a sheet.

[0028] The present disclosure (22) is a binder for an electrochemical device substantially composed of only a tetrafluoroethylene-based polymer composition. The tetrafluoroethylene-based polymer composition includes a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, has a fibrillated portion, and has an endothermic peak temperature of 327°C or higher and 350°C or lower. It is a binder for an electrochemical device.

[0029] The present disclosure (23) is the binder for an electrochemical device according to the present disclosure (22), wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorinated monomer having a carboxyl group, a non-fluorinated monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6). CH2=CR 11 -CO-O-R 13 (10-1) (In the formula, R 11is a hydrogen atom or an alkyl group, and R 13 is a hydrogen atom or an alkyl group.) CX2=CY(-CZ2-O-Rf-Y 3 )(5) (In the formula, X is the same or different and is -H or -F; Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is -H, -F, an alkyl group, or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.) CX2=CY(-O-Rf-Y 3 )(6) (In the formula, X is the same or different and is -H or -F; Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is a hydrophilic group.)

[0030] The present disclosure (24) is a binder for a lithium ion secondary battery and is a binder for an electrochemical device described in the present disclosure (22) or (23) which is a sheet.

[0031] The present disclosure (25) is an electrode mixture containing a tetrafluoroethylene-based polymer composition described in any one of the present disclosures (1) to (4), (19) to (21), or a binder for an electrochemical device described in any one of the present disclosures (5) to (18), (22) to (24), and an electrode active material.

[0032] The present disclosure (26) is an electrode mixture described in the present disclosure (25) which is a sheet.

[0033] The present disclosure (27) is an electrode containing a tetrafluoroethylene-based polymer composition described in any one of the present disclosures (1) to (4), (19) to (21), or a binder for an electrochemical device described in any one of the present disclosures (5) to (18), (22) to (24), an electrode active material, and a current collector.

[0034] The present disclosure (28) is a secondary battery including the electrode described in the present disclosure (27).

Effects of the Invention

[0035] According to the present disclosure, it is possible to provide a tetrafluoroethylene-based polymer composition for a binder for an electrochemical device, which can improve the high-temperature cycle characteristics of the electrochemical device and suppress gas generation, and a binder for an electrochemical device, an electrode binder, an electrode, and a secondary battery using the same.

Embodiments for Carrying Out the Invention

[0036] In the present disclosure, the “organic group” means a group containing one or more carbon atoms or a group formed by removing one hydrogen atom from an organic compound. As the above organic group, an alkyl group which may have one or more substituents is preferable.

[0037] Hereinafter, the present disclosure will be specifically described.

[0038] The present disclosure provides a tetrafluoroethylene (TFE)-based polymer composition used as a binder for an electrochemical device, including a TFE-based polymer which is a copolymer of TFE and a monomer having a polar group, and having a fibrillating ability (hereinafter, also referred to as the TFE-based polymer composition (1) of the present disclosure).

[0039] By having the above configuration, when the TFE-based polymer composition (1) of the present disclosure is used as a binder for an electrochemical device, it is possible to improve the high-temperature cycle characteristics of the electrochemical device and suppress gas generation. Further, it is also possible to obtain a binder sheet excellent in strength and flexibility. The TFE-based polymer composition (1) of the present disclosure can also be used dry, so it is not necessary to use a large amount of dispersion media such as water and organic solvents, and a wide range of electrode active materials and solid electrolytes to be combined can be selected, which is advantageous in the production process. In addition, the processes and costs associated with the use of dispersion media can be reduced. Furthermore, since the TFE-based polymer composition (1) of the present disclosure has excellent adhesion to active materials and electrolytes, the amount used can be reduced.

[0040] The TFE-based polymer composition (1) of the present disclosure contains a TFE-based polymer that is a copolymer of TFE and a monomer having a polar group. The above polar group is a group having polarity. Examples of the polar group include at least one functional group selected from the group consisting of an amino group, a nitrile group, and an oxygen-containing polar group. Among them, at least one selected from the group consisting of a nitrile group and an oxygen-containing polar group is preferable, and an oxygen-containing polar group is more preferable.

[0041] Examples of the oxygen-containing polar group include, for example, a carbonyl group-containing group, an epoxy group, an oxetanyl group, -SO3X a , -SO2X a , -OSO2X a , -PO3X a , and -OX a (wherein X a is -H, a metal atom, -NR 1 4, an imidazolium optionally having a substituent, a pyridinium optionally having a substituent, or a phosphonium optionally having a substituent, an alkyl group, or a nitrile group. R 1 is H or an organic group.) and at least one functional group selected from the group consisting of them. Among them, at least one selected from the group consisting of a carbonyl group-containing group, -SO3X a , and -OX a is preferable, and at least one selected from the group consisting of a carbonyl group-containing group and -SO3X a is more preferable.

[0042] Examples of the carbonyl group-containing group include -COOX a , -OCOX a (In the formula, X a is the same as defined above.), carbonate group, halocarbonyl group, acid anhydride residue, isocyanate group, and the like. Among them, at least one selected from the group consisting of -COOX a , -OCOX a , and acid anhydride residue is preferable, and at least one selected from the group consisting of -COOX a and acid anhydride residue is more preferable.

[0043] X a is -H, a metal atom, -NR 1 4, optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, an alkyl group, or a nitrile group. Examples of the metal atom in X a include monovalent and divalent metal atoms, such as alkali metals (Group 1) or alkaline earth metals (Group 2), and specific examples include Na, K, Li, etc. The four R 1 may be the same or different. R 1 is preferably 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. The alkyl group in X a preferably has 1 or more carbon atoms, preferably 10 or less carbon atoms, more preferably 6 or less carbon atoms, and even more preferably 4 or less carbon atoms. The alkyl group may be linear or cyclic. When the alkyl group is cyclic, it corresponds to a cycloalkyl group. X a is preferably -H, an alkali metal atom, NH4, an alkyl group, or a nitrile group, more preferably -H, an alkali metal atom, NH4, or an alkyl group, and even more preferably -H, an alkali metal atom, or NH4.

[0044] The monomer having the polar group may be a non-fluorinated monomer or a fluorinated monomer, but a non-fluorinated monomer is preferred.

[0045] Examples of the non-fluorine monomer include non-fluorine monomers having a hydroxyl group such as hydroxyalkyl vinyl ethers like hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyisobutyl vinyl ether, hydroxycyclohexyl vinyl ether; non-fluorine monomers having a carboxyl group such as acrylic acid, methacrylic acid, itaconic acid, succinic acid, fumaric acid, crotonic acid, maleic acid, citraconic acid, undecylenic acid, acetylenedicarboxylic acid; non-fluorine monomers having an acid anhydride residue such as itaconic anhydride (hereinafter also referred to as "IAH"), citraconic anhydride (hereinafter also referred to as "CAH"), 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), succinic anhydride, fumaric anhydride, maleic anhydride; non-fluorine monomers having a sulfo group such as vinyl sulfonic acid; non-fluorine monomers having an epoxy group (glycidyl group) such as glycidyl vinyl ether, glycidyl allyl ether; non-fluorine monomers having an amino group such as aminoalkyl vinyl ether, aminoalkyl allyl ether; non-fluorine monomers having an amide group such as (meth)acrylamide, methylolacrylamide; non-fluorine monomers having a nitrile group such as acrylonitrile, methacrylonitrile, and the like. Among these, non-fluorine monomers having a carboxyl group and non-fluorine monomers having an acid anhydride residue are preferred, non-fluorine monomers having an acid anhydride residue are more preferred, and cyclic non-fluorine monomers having an acid anhydride residue are even more preferred. It is also preferred that they are non-fluorine monomers having a carboxyl group or a sulfo group.

[0046] It is also preferable that the non-fluorine monomer is a monomer (10) represented by the following general formula (10). Formula (10): CH2=CR 11 -L 11 -R 12 R 11 represents a hydrogen atom or an alkyl group. The number of carbon atoms of the alkyl group is preferably 1 to 3, and more preferably 1. L 11 represents a single bond, -CO-O-*, -O-CO-*, or -O-. * represents the bonding position with R 12 . For example, when L 11 is -CO-O-*, formula (10) represents CH2=CR 11 -CO-O-R 12 . R 12 represents a hydrogen atom, an alkyl group, or a nitrile group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 4. The alkyl group may be linear or cyclic. When the alkyl group is cyclic, it corresponds to a cycloalkyl group.

[0047] As the monomer (10), a monomer selected from the group consisting of the monomer represented by formula (10-1), the monomer represented by formula (10-2), the monomer represented by formula (10-3), and the monomer represented by formula (10-4) is preferred. Formula (10-1) CH2=CR 11 -CO-O-R 13 Formula (10-2) CH2=CR 11 -O-CO-R 14 Formula (10-3) CH2=CR 11 -O-R 15 Formula (10-4) CH2=CR 11 -R 16 R 11 is defined as described above. R 13 represents a hydrogen atom or an alkyl group, and an alkyl group having 1 to 6 carbon atoms is preferred. R 14 represents an alkyl group, and an alkyl group having 1 to 3 carbon atoms is preferred, and a methyl group is more preferred. R 15 represents an alkyl group, and a linear alkyl group or a cyclic alkyl group is preferred. R 16 represents a nitrile group.

[0048] Examples of the monomer (10) include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, vinyl methacrylate, vinyl acetate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, ethyl vinyl ether, and cyclohexyl vinyl ether. As the monomer (10), the monomer represented by the formula (10-1) and the monomer represented by the formula (10-2) are more preferable, and R 13 The monomer represented by the formula (10-1) in which is an alkyl group having 1 to 6 carbon atoms is particularly preferable.

[0049] It is also preferable that the monomer having the polar group includes a modified monomer having a functional group capable of reacting by radical polymerization and a hydrophilic group (hereinafter referred to as "modified monomer (A)").

[0050] Examples of the hydrophilic group in the modified monomer (A) include -NH2, -PO3M, -OPO3M, -SO3M, -OSO3M, -COOM (in each formula, M is H, a metal atom, NR 7 4, imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent, and R 7 is H or an organic group, and they may be the same or different. Any two of them may be bonded to each other to form a ring.). Among the above hydrophilic groups, -SO3M or -COOM is preferable. R 7 is preferably H or an organic group of C 1-10 is preferably H or an organic group of C 1-4 is more preferably H or an organic group of C 1-4 and further preferably an alkyl group of C. Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferable.

[0051] Examples of the "functional group capable of reacting by radical polymerization" in the modified monomer (A) include groups having an ethylenically unsaturated bond such as a vinyl group and an allyl group. The group having an ethylenically unsaturated bond can be represented by the following formula: CX e X g =CX f R- (In the formula, X e , X f and X g are each independently F, Cl, H, CF3, CF2H, CFH2, or CH3; and R is a linking group.) The linking group of R includes the linking group as R a described later. Preferably, groups having an unsaturated bond such as -CH=CH2, -CF=CH 2、 -CH=CF 2、 -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=CF2 are mentioned.

[0052] Since the modified monomer (A) has a functional group capable of reacting by radical polymerization, when used in polymerization, it is presumed to react with the fluorine-containing monomer at the initial stage of the polymerization reaction to form particles having a hydrophilic group derived from the modified monomer (A) and high stability. Therefore, when polymerization is carried out in the presence of the modified monomer (A), it is considered that the number of particles increases.

[0053] The above-mentioned modified monomer (A) may be used alone or in combination of two or more.

[0054] As the above-mentioned modified monomer (A), a compound having an unsaturated bond can be used.

[0055] The modified monomer (A) has the general formula (4): CX i X k =CX j R a -(CZ 1 Z 2 ) k -Y 3 (4) (In the formula, X i , X j and X k are each independently F, Cl, H or CF3; Y 3 is a hydrophilic group; R a is a linking group; Z 1 and Z 2 are each independently H, F or CF3, and k is 0 or 1). A compound represented by is preferred.) Examples of the hydrophilic group include, for example, -NH2, -PO3M, -OPO3M, -SO3M, -OSO3M, -COOM (in each formula, M is H, a metal atom, NR 7 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, R 7 is H or an organic group, and may be the same or different. Any two of them may be bonded to each other to form a ring.). Among them, as the hydrophilic group, -SO3M or -COOM is preferred. As R 7 , H or a C 1-10 organic group is preferred, H or a C 1-4 organic group is more preferred, and an alkyl group of H or C 1-4 is even more preferred.) Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1), alkaline earth metals (Group 2), etc., and Na, K or Li is preferred.) By using the modified monomer (A), an aqueous dispersion having a smaller average primary particle diameter and better stability can be obtained. Also, the aspect ratio of the primary particles can be made smaller.)

[0056] The above R ais a linking group. In this specification, "linking group" refers to a divalent linking group. The linking group may be a single bond, preferably contains at least one carbon atom, and the number of carbon atoms may be 2 or more, 4 or more, 8 or more, 10 or more, or even 20 or more. The upper limit is not limited, for example, it may be 100 or less, or 50 or less. The above linking group may be linear or branched, cyclic or acyclic, saturated or unsaturated, substituted or unsubstituted, and optionally contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen, and optionally contains one or more functional groups selected from the group consisting of ester, amide, sulfonamide, carbonyl, carbonate, urethane, urea, and carbamate. The above linking group may not contain a carbon atom and may be a chain heteroatom such as oxygen, sulfur, or nitrogen.

[0057] The above R a is preferably, for example, a chain heteroatom such as oxygen, sulfur, nitrogen, or a divalent organic group. R a When is a divalent organic group, the hydrogen atom bonded to the carbon atom may be replaced by a halogen other than fluorine, such as chlorine, and may or may not contain a double bond. Also, R a may be either linear or branched, and may be either cyclic or acyclic. Also, R a may contain a functional group (for example, ester, ether, ketone, amine, halide, etc.). R a may also be a non-fluorinated divalent organic group, or a partially fluorinated or perfluorinated divalent organic group. R aExamples include hydrocarbon groups in which no fluorine atom is bonded to a carbon atom, hydrocarbon groups in which some of the hydrogen atoms bonded to a carbon atom are substituted with fluorine atoms, hydrocarbon groups in which all of the hydrogen atoms bonded to a carbon atom are substituted with fluorine atoms, -(C=O)-, -(C=O)-O-, or a hydrocarbon group containing -(C=O)-, which may contain an oxygen atom, may contain a double bond, and may contain a functional group.

[0058] R a is preferably a hydrocarbon group having 1 to 100 carbon atoms, which may contain an ether bond and may contain a carbonyl group, and some or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with fluorine. R a Preferably, it is -(CH2) 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 at least one selected from combinations thereof. Wherein a, b, c and d are each independently at least 1 or more. a, b, c and d may each independently be 2 or more, 3 or more, 4 or more, 10 or more, 20 or more. The upper limit of a, b, c and d is, for example, 100.

[0059] R aSuitable specific examples include: -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-, etc. Among them, the above R a Specifically, -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- is preferred. In the above formula, n is an integer from 1 to 10.

[0060] -R in the above general formula (4) a -(CZ 1 Z 2) k include -CF2-O-CF2-, -CF2-O-CF(CF3)-, -CF2-O-C(CF3)2-, -CF2-O-CF2-CF2-, -CF2-O-CF2-CF(CF3)-, -CF2-O-CF2-C(CF3)2-, -CF2-O-CF2CF2-CF2-, -CF2-O-CF2CF2-CF(CF3)-, -CF2-O-CF2CF2-C(CF3)2-, -CF2-O-CF(CF3)-CF2-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF3)-C(CF3)2-, -CF2-O-CF(CF3)-CF2-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF3)-C(CF3)2-, -CF2-O-CF(CF3)CF2-CF2-, -CF2-O-CF(CF3)CF2-CF(CF3)-, -CF2-O-CF(CF3)CF2-C(CF3)2-, -CF2-O-CF(CF3)CF2-O-CF2-, -CF2-O-CF(CF3)CF2-O-CF(CF3)-, -CF2-O-CF(CF3)CF2-O-C(CF3)2-, -(C=O)-, -(C=O)-O-, -(C=O)-(CH2)-, -(C=O)-(CF2)-, -(C=O)-O-(CH2)-, -(C=O)-O-(CF2)-, -(C=O)-[(CH2)2-O] n -(CH2)-, -(C=O)-[(CF2)2-O] n -(CF2)-, -(C=O)-[(CH2)2-O] n -(CH2)-(CH2)-, -(C=O)-[(CF2)2-O] n -(CF2)-(CF2)-, -(C=O)-O[(CH2)2-O] n -(CF2)-, -(C=O)-O[(CH2)2-O] n -(CH2)-(CH2)-, -(C=O)-O[(CF2)2-O] n -(CF2)-, -(C=O)-O[(CF2)2-O] n-(CF2)-(CF2)-, -(C=O)-(CH2)2-O-(CH2)-(CH2)-, -(C=O)-(CF2)2-O-(CF2)-(CF2)-, -(C=O)-O-(CH2)2-O-(CH2)-(CH2)-, -(C=O)-O-(CF2)2-O-(CF2)-(CF2)-, -(C=O)-O-(CH2)2-O-(CH2)-C(CF3)2-, -(C=O)-O-(CF2)2-O-(CF2)-C(CF3)2-, or -(C=O)-O-C6H4-C(CF3)2- is preferred, and -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- is more preferred. In the above formula, n is an integer from 1 to 10.

[0061] Specific examples of the compound represented by the general formula (4) include

Chemical formula

[0062] R a As, the following general formula (r1): -(C=O) h -(O) i -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g -(r1) (In the formula, X 6Each is independently H, F, or CF3, e is an integer from 0 to 3, f is an integer from 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1), and a divalent group represented by the following general formula (r2) is preferred: -(C=O) h -(O) i -CF2-O-(CX 7 2) e -(O) g -(r2) (In the formula, X 7 Each is independently H, F, or CF3, e is an integer from 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1.) A divalent group represented by is also preferred.

[0063] -R in the above general formula (4) a -CZ 1 Z 2 -As, the following formula (t1): -(C=O) h -(O) i -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g -CZ 1 Z 2 -(t1) (In the formula, X 6 Each is independently H, F, or CF3, e is an integer from 0 to 3, f is an integer from 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, and Z 1 and Z 2 Each is independently F or CF3) A divalent group represented by is also preferred. In formula (t1), Z 1 and Z 2 It is more preferable that one is F and the other is CF3. Also, in the above general formula (4), -R a -CZ 1 Z 2 -As, the following formula (t2): -(C=O) h -(O) i -CF2-O-(CX 7 2)e -(O) g -CZ 1 Z 2 -(t2) (wherein X 7 is independently H, F, or CF3, e is an integer from 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, and Z 1 and Z 2 are each independently H, F, or CF3), and the divalent group represented by the formula (t2) is also preferred. In the formula (t2), it is more preferred that one of Z 1 and Z 2 is F and the other is CF3.

[0064] The compound represented by the general formula (4) preferably has a C-F bond and no C-H bond except for the hydrophilic group (Y 3 ). That is, in the general formula (4), all of X i , X j , and X k are F, and R a is preferably a perfluoroalkylene group having 1 or more carbon atoms. The above perfluoroalkylene group may be linear or branched, cyclic or acyclic, and may contain at least one chain heteroatom. The carbon number of the above perfluoroalkylene group may be 2 to 20, or may be 4 to 18.

[0065] The compound represented by the general formula (4) may be partially fluorinated. That is, the compound represented by the general formula (4) preferably has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom except for the hydrophilic group (Y 3 ).

[0066] The compound represented by the general formula (4) is also preferably a compound represented by the following formula (4a). CF2=CF-O-Rf 0 -Y 3 (4a) (wherein Y 3 is a hydrophilic group and Rf 0is perfluorinated and may be linear or branched, cyclic or acyclic, saturated or unsaturated, substituted or unsubstituted, and optionally further contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen.

[0067] The compound represented by the general formula (4) is preferably a compound represented by the following formula (4b). CH2=CH-O-Rf 0 -Y 3 (4b) (In the formula, Y 3 is a hydrophilic group, and Rf 0 is a perfluorinated divalent linking group defined by formula (4a).)

[0068] In the general formula (4), Y 3 is preferably one form of -OSO3M. When Y 3 is -OSO3M, examples of the polymerizable unit based on the compound represented by the general formula (4) include -[CF2CF(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)]-, etc. In the above formulas, M is the same as above.

[0069] In the general formula (4), Y 3 is also preferably one form of -SO3M. When Y 3When it is -SO3M, examples of the polymerizable unit based on the compound represented by the general formula (4) include -[CF2CF(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)]-, etc. In the above formula, M is the same as defined above.

[0070] In the general formula (4), Y 3 being -COOM is also one of the preferred forms. Y 3 When Y is -COOM, examples of the polymerizable unit based on the compound represented by the general formula (4) include -[CF2CF(OCF2CF2COOM)]-, -[CF2CF(O(CF2)5COOM)]-, -[CF2CF(OCF2CF(CF3)COOM)]-, -[CF2CF(OCF2CF(CF3)O(CF2) n COOM)]- (n is 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)]-, etc. In the above formula, R’ is H or C1-4 is an alkyl group, and M is the same as above.

[0071] In general formula (4), Y 3 being -OPO3M is also one of the preferred forms. Y 3 When Y is -OPO3M, examples of the polymerizable unit based on the compound represented by general formula (4) include -[CF2CF(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)]-, etc. In the above formula, M is the same as above.

[0072] In general formula (4), Y 3 being -PO3M is also one of the preferred forms. Y 3 When Y is -PO3M, examples of the polymerizable unit based on the compound represented by general formula (4) include -[CF2CF(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)]-, and in the formula, M is the same as above.

[0073] As the compound represented by the general formula (4) above, the following general formula (5): CX2=CY(-CZ2-O-Rf-Y 3 )(5) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group, and Z is the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is the same as described above.) A monomer represented by the following general formula (6): CX2=CY(-O-Rf-Y 3 )(6) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group, and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is the same as described above.) A monomer represented by the following general formula (7): CX2=CY(-Rf-Y 3 )(7) (In the formula, X is the same or different and is -H or -F, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group, and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. Y 3 is the same as described above.) It is preferably at least one selected from the group consisting of monomers represented by

[0074] In the general formula (5) above, X is -H or -F. Both X may be -F, or at least one may be -H. For example, one may be -F and the other may be -H, or both may be -H.

[0075] In the general formula (5) above, Y is -H, -F, an alkyl group or a fluorine-containing alkyl group. The above alkyl group is an alkyl group that does not contain a fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less. The above fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above fluorine-containing alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less. As the above Y, -H, -F or -CF3 is preferable, and -F is more preferable.

[0076] In the above general formula (5), Z is the same or different and is -H, -F, an alkyl group or a fluoroalkyl group. The above alkyl group is an alkyl group that does not contain a fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less. The above fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above fluorine-containing alkyl group is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less. As the above Z, -H, -F or -CF3 is preferable, and -F is more preferable.

[0077] In the above general formula (5), at least one of the above X, Y and Z preferably contains a fluorine atom. For example, X may be -H, and Y and Z may be -F.

[0078] In the above general formula (5), the above Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. The number of carbon atoms of the fluorine-containing alkylene group is preferably 2 or more. Also, it is preferably 30 or less, more preferably 20 or less, and still more preferably 10 or less. Examples of the fluorine-containing alkylene group include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, -CF(CF3)CH2-, and the like. The fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0079] The number of carbon atoms of the fluorine-containing alkylene group having an ether bond is preferably 3 or more. Also, it is preferably 60 or less, more preferably 30 or less, and still more preferably 12 or less. For example, the following formula:

Chemical formula

[0080] In the general formula (5) above, Y 3 is -COOM, -SO3M or -OSO3M (M is H, a metal atom, NR 7 4, imidazolium which may have a substituent, pyridinium which may have a substituent or phosphonium which may have a substituent, R 7 is H or an organic group, and they may be the same or different. Any two of them may be bonded to each other to form a ring.). R 7 is preferably H or an organic group of C 1-10 and more preferably H or an organic group of C 1-4 and still more preferably H or an alkyl group of C 1-4 . Examples of the above metal atom include an alkali metal (Group 1) and an alkaline earth metal (Group 2), and Na, K or Li is preferred. As the above M, -H, a metal atom or -NR 7 4 is preferred, -H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or -NR 7 4 is more preferred, -H, -Na, -K, -Li or -NH4 is still more preferred, -Na, -K or -NH4 is still more preferably, -Na or -NH4 is particularly preferred, and -NH4 is most preferred. As the above Y 3 , -COOM or -SO3M is preferred, and -COOM is more preferred.

[0081] Examples of the monomer represented by the general formula (5) include the following formula (5a): CX h 2 = CFCF2 - O - (CF(CF3)CF2O) n5 -CF(CF3)-Y 3 (5a) (In the formula, each X h is the same and represents F or H. n5 represents 0 or an integer of 1 to 10, and Y 3 is as defined above.). A fluoroallyl ether compound represented by the formula is preferably exemplified. In general formula (5a), n5 is preferably an integer of 0 or 1 to 5, more preferably 0, 1 or 2, and still more preferably 0 or 1 in terms of obtaining TFE-based polymer particles with a small primary particle size. The above Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and surface activity. M is preferably H or NH4 in terms of being less likely to remain as an impurity and improving the heat resistance of the obtained composition and the stretched body obtained from the composition.

[0082] The monomer represented by general formula (5) is preferably the monomer (5b) represented by the following general formula (5b). CH2=CF(-CF2-O-Rf-Y 3 )(5b) (In the formula, Rf and Y 3 are the same as described above.)

[0083] Specific examples of the monomer represented by general formula (5b) include the following formula

[0084]

Chemical formula

[0085] (In the formula, Z 1 is F or CF3; Z 2 and Z 3 are each H or F; Z 4 is H, F or CF3; p1 + q1 + r1 is an integer from 0 to 10; s1 is 0 or 1; t1 is an integer from 0 to 5, and Y 3 is the same as described above. However, when both Z 3 and Z 4 are H, p1 + q1 + r1 + s1 is not 0). Examples of the monomer include, more specifically,

[0086]

Chemical formula

[0087] etc. are preferably mentioned, and among them,

[0088]

Chem.

[0089] is preferably.

[0090] As the monomer represented by the general formula (5b), Y in the formula (5b) 3 is preferably -COOM, and in particular, at least one selected from the group consisting of CH2 = CFCF2OCF(CF3)COOM and CH2 = CFCF2OCF(CF3)CF2OCF(CF3)COOM (wherein M is the same as defined above) is preferred, and CH2 = CFCF2OCF(CF3)COOM is more preferred.

[0091] The monomer represented by the general formula (5) is preferably the monomer (5c) represented by the following general formula (5c). CX 2 2 = CFCF2 - O - (CF(CF3)CF2O) n5 -CF(CF3)-Y 3 (5c) (wherein each X 2 is the same and represents F or H. n5 represents 0 or an integer from 1 to 10, and Y 3 is the same as defined above.)

[0092] In the above formula (5c), the above n5 is preferably 0 or an integer from 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, in terms of the stability of the resulting aqueous dispersion. The above Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion, and the above M 1 is preferably H or NH4 in terms of being difficult to remain as an impurity and improving the heat resistance of the obtained molded body. 1

[0093] Examples of the perfluorovinyl alkyl compound represented by the above formula (5c) include CH2 = CFCF2OCF(CF3)COOM 1, CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOM 1 (wherein M 1 is the same as defined above.) are included.

[0094] In addition, examples of the monomer represented by the general formula (5) include a monomer represented by the following general formula (5d), a monomer represented by the following general formula (5e), and the like.

[0095] CF2=CFCF2-O-Rf-Y 3 (5d) CF2=CF-Rf-Y 3 (5e) (wherein Rf and Y 3 are the same as above)

[0096] More specifically,

Chemical formula

[0097] In the above general formula (6), X is -H or -F. Both X may be -F, or at least one of them may be -H. For example, one may be -F and the other may be -H, or both may be -H.

[0098] In the above general formula (6), Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group. The above alkyl group is an alkyl group that does not contain a fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above alkyl group is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less. The above fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms of the above fluorine-containing alkyl group is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less. As the above Y, -H, -F, or -CF3 is preferable, and -F is more preferable.

[0099] In the above general formula (6), at least one of the above X and Y preferably contains a fluorine atom. For example, X may be -H, and Y and Z may be -F.

[0100] In the above general formula (6), the above Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having an ether bond and having 2 to 100 carbon atoms. The number of carbon atoms of the above fluorine-containing 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 above fluorine-containing alkylene group include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, -CF(CF3)CH2-, etc. The above fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0101] 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 formulas (6a), (6b), (6c) and (6d). CF2=CF-(CF2) n1 -Y 3 (6a) (In the formula, n1 represents an integer of 1 to 10, and Y 3 represents -SO3M 1 or -COOM 1 , M 1 represents H, a metal atom, NR 7 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent or a phosphonium which may have a substituent, and R 7 represents H or an organic group.) CF2=CF-(CF2C(CF3)F) n2 -Y 3 (6b) (In the formula, n2 represents an integer of 1 to 5, and Y 3 is the same as defined above.) CF2=CF-O-(CFX 1 ) n3 -Y 3 (6c) (In the formula, X1 represents F or CF3, n3 represents an integer from 1 to 10, and Y 3 is the same as the above definition.) CF2=CF-O-(CF2CFX 1 O) n4 -CF2CF2-Y 3 (6d) (wherein n4 represents an integer from 1 to 10, and Y 3 and X 1 are the same as the above definition.)

[0102] In the above formula (6a), it is preferable that the above n1 is an integer of 5 or less, and more preferably an integer of 2 or less. The above Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion. 1 M 1 is preferably H or NH4 in terms of being difficult to remain as an impurity and improving the heat resistance of the resulting molded body.

[0103] Examples of the perfluorovinyl alkyl compound represented by the above formula (6a) include CF2=CFCF2COOM 1 (wherein M 1 is the same as the above definition.)

[0104] In the above formula (6b), it is preferable that the above n2 is an integer of 3 or less in terms of the stability of the resulting aqueous dispersion, and Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion. 1 M 1 is preferably H or NH4 in terms of being difficult to remain as an impurity and improving the heat resistance of the resulting molded body.

[0105] In the above formula (6c), it is preferable that the above n3 is an integer of 5 or less in terms of water solubility, and the above Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion. 1 M 1is preferably H or NH4 in terms of improving the dispersion stability.

[0106] In the above formula (6d), the above X 1 is preferably -CF3 in terms of the stability of the aqueous dispersion, the above n4 is preferably an integer of 5 or less in terms of water solubility, and the above Y 3 is preferably -COOM 1 in terms of obtaining appropriate water solubility and the stability of the aqueous dispersion, and the above M 1 is preferably H or NH4.

[0107] Examples of the perfluorovinyl ether compound represented by the above formula (6d) include CF2=CFOCF2CF(CF3)OCF2CF2COOM 1 (wherein M 1 represents H, NH4 or an alkali metal).

[0108] In the above general formula (7), Rf is preferably a fluorine-containing alkylene group having 1 to 40 carbon atoms. In the general formula (7), at least one of X and Y preferably contains a fluorine atom.

[0109] The monomer represented by the above general formula (7) is the following general formula (7a): CF2=CF-(CF2) n1 -Y 3 (7a) (wherein n1 represents an integer of 1 to 10, and Y 3 is as defined above), and at least one selected from the group consisting of monomers represented by the following general formula (7b): CF2=CF-(CF2C(CF3)F) n2 -Y 3 (7b) (wherein n2 represents an integer of 1 to 5, and Y 3 is as defined above) is preferred. The above Y 3 is preferably -SO3M 1 or -COOM 1 and M 1is H, a metal atom, NR 7 4, preferably an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium. The above R 7 represents H or an organic group.

[0110] In the above formula (7a), the above n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. The above Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion. 1 M 1 is preferably H or NH4 in that it is difficult to remain as an impurity and the heat resistance of the resulting molded article is improved. Examples of the perfluorovinylalkyl compound represented by the above formula (7a) include CF2 = CFCF2COOM 1 (wherein M 1 is the same as defined above).

[0111] In the above formula (7b), the above n2 is preferably an integer of 3 or less in terms of the stability of the resulting aqueous dispersion. Y 3 is preferably -COOM in terms of obtaining appropriate water solubility and stability of the aqueous dispersion. 1 M 1 is preferably H or NH4 in that it is difficult to remain as an impurity and the heat resistance of the resulting molded article is improved.

[0112] The modified monomer (A) is preferably at least one selected from the group consisting of compounds represented by general formula (5c), general formula (6a), general formula (6b), general formula (6c), and general formula (6d), and more preferably a compound represented by general formula (5c).

[0113] The content of the polymerization unit based on the monomer having the polar group (monomer unit having a polar group) is preferably in the range of 0.0001 to 1.0% by mass with respect to all the polymerization units, in terms of improving cycle characteristics and suppressing gas generation, and obtaining a composite sheet excellent in strength and flexibility. As the lower limit of the content of the monomer unit having a polar group, 0.0005% by mass is more preferable, 0.001% by mass is further preferable, 0.002% by mass is even more preferable. As the upper limit of the content of the monomer unit having a polar group, 0.8% by mass is more preferable, 0.5% by mass is further preferable, 0.3% by mass is even more preferable, 0.2% by mass is even more preferable, and 0.1% by mass is particularly preferable.

[0114] The total amount of the polymerization unit based on TFE (TFE unit) and the monomer unit having a polar group is preferably 95.0% by mass or more, more preferably 97.0% by mass or more, further preferably 99.0% by mass or more, even more preferably 99.5% by mass or more, and particularly preferably 99.9% by mass or more with respect to all the polymerization units. The upper limit is not particularly limited and may be, for example, 100% by mass.

[0115] The above TFE-based polymer may further contain a polymerization unit (other monomer unit) based on a monomer other than TFE and the monomer having a polar group (other monomer).

[0116] The above other monomer is not particularly limited as long as it can copolymerize with TFE and the monomer having a polar group. For example, perfluoroolefins such as hexafluoropropylene [HFP]; hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride [VDF]; perhaloolefins such as chlorotrifluoroethylene [CTFE]; perfluorovinyl ether; perfluoroallyl ether; (perfluoroalkyl)ethylene, ethylene, etc. may be mentioned. Also, the other monomer used may be one kind or a plurality of kinds.

[0117] The above perfluorovinyl ether is not particularly limited. For example, the following general formula (A): CF2=CF-ORf 1 (A) (In the formula, Rf 1 represents a perfluoro organic group.) Examples thereof include perfluoro unsaturated compounds represented by the formula. In the present specification, the above-mentioned "perfluoro organic group" means an organic group in which all hydrogen atoms bonded to carbon atoms are substituted by fluorine atoms. The above-mentioned perfluoro organic group may have an ether oxygen.

[0118] Examples of the above-mentioned perfluorovinyl ether include, for example, in the above general formula (A), Rf 1 is a perfluoro(alkyl vinyl ether) [PAVE] in which the perfluoroalkyl group has 1 to 10 carbon atoms. The number of carbon atoms of the above-mentioned perfluoroalkyl group is preferably 1 to 5.

[0119] Examples of the perfluoroalkyl group in the above-mentioned PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, and the like.

[0120] Examples of the above-mentioned perfluorovinyl ether further include, in the above general formula (A), those in which Rf 1 is a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, Rf 1 is a group represented by the following formula:

[0121]

Chemical formula

[0122] (In the formula, m represents an integer of 0 or 1 to 4.), those in which Rf 1 is a group represented by the following formula:

[0123]

Chemical formula

[0124] Groups represented by (wherein n represents an integer of 1 to 4) and the like can be mentioned.

[0125] The (perfluoroalkyl)ethylene [PFAE] is not particularly limited, and examples thereof include (perfluorobutyl)ethylene [PFBE], (perfluorohexyl)ethylene, and the like.

[0126] Examples of the perfluoroallyl ether include the general formula (B): CF2=CF-CF2-ORf 2 (B) (wherein Rf 2 represents a perfluoro organic group). Fluoromonomers represented by this formula can be mentioned.

[0127] The above Rf 2 is preferably a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. As the above perfluoroallyl ether, at least one selected from the group consisting of CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9 is preferable, at least one selected from the group consisting of CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9 is more preferable, and CF2=CF-CF2-O-CF2CF2CF3 is even more preferable.

[0128] The above other monomer is represented by the following general formula (i): CX 1 X 2 =CX 3 X 4 (i) (wherein X 1 to X 3 are each independently H or F. X 4 is F, Cl, Rf or O-Rf. Rf is a perfluoro organic group). It is preferably a compound represented by this formula.

[0129] As Rf in the general formula (i), a perfluoroalkyl group having 1 to 10 carbon atoms is preferable, a perfluoroalkyl group having 1 to 5 carbon atoms is more preferable, and a perfluoroalkyl group having 1 to 4 carbon atoms is still more preferable.

[0130] As the above-mentioned other monomer, at least one selected from the group consisting of HFP, PAVE, and PFAE is preferable in terms of improving stretchability, adhesiveness, and flexibility of the binder sheet. At least one selected from the group consisting of HFP, perfluoro(methyl vinyl ether) [PMVE], perfluoro(propyl vinyl ether) [PPVE], and PFBE is more preferable. At least one selected from the group consisting of HFP, PMVE, and PPVE is still more preferable. At least one selected from the group consisting of HFP and PPVE is even more preferable. HFP is even more preferable.

[0131] The above TFE-based polymer may be a TFE copolymer containing a TFE unit and a polymerization unit (modified monomer unit) based on a modified monomer copolymerizable with TFE. The above modified monomer includes the monomer having the above-mentioned polar group and other monomers. The above TFE-based polymer is preferably polytetrafluoroethylene (PTFE) in terms of improving cycle characteristics and suppressing gas generation, and obtaining a binder sheet excellent in strength and flexibility. A modified PTFE containing 99.0% by mass or more of TFE units and 1.0% by mass or less of modified monomer units is more preferable.

[0132] The content of the modified monomer unit (the total amount of the monomer unit having a polar group and other monomer units) is preferably in the range of 0.0001 to 10% by mass based on all the polymerization units in terms of improving the cycle characteristics and suppressing gas generation, and obtaining a composite sheet excellent in strength and flexibility. As the lower limit of the content of the modified monomer unit, 0.001% by mass is more preferable, 0.010% by mass is further preferable, 0.015% by mass is even more preferable, and 0.020% by mass is particularly preferable. As the upper limit of the content of the modified monomer unit, 5.0% by mass is preferable, 3.0% by mass is more preferable, 1.0% by mass is further preferable, 0.80% by mass is even more preferable, 0.60% by mass is even more preferable, 0.50% by mass is even more preferable, 0.40% by mass is even more preferable, 0.30% by mass is even more preferable, and 0.20% by mass is particularly preferable. In the present specification, the above-mentioned modified monomer unit means a part of the molecular structure of the TFE-based polymer and is a part derived from the modified monomer.

[0133] The content of each of the above-mentioned polymerization units can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis according to the type of monomer.

[0134] The above-mentioned TFE-based polymer may have a core-shell structure. Examples of the TFE-based polymer having a core-shell structure include modified PTFE containing a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE in the particles. Examples of such modified PTFE include PTFE described in JP-T-2005-527652.

[0135] The above-mentioned TFE-based polymer is preferably non-melt processable. In the present specification, being non-melt processable means that the melt flow rate (MFR) is less than 0.25 g / 10 min, preferably less than 0.10 g / 10 min, more preferably less than 0.05 g / 10 min, and even more preferably less than 0.01 g / 10 min. The above MFR is a value obtained as the mass (g / 10 min) of the polymer flowing out per 10 minutes from a nozzle with an inner diameter of 2.095 mm and a length of 8 mm at 372 °C and a load of 5 kg using a melt indexer in accordance with ASTM D1238.

[0136] In the TFE-based polymer composition (1) of the present disclosure, the content of the above TFE-based polymer may be 95.0% by mass or more, preferably 98.0% by mass or more, more preferably 99.0% by mass or more, still more preferably 99.5% by mass or more, particularly preferably 99.9% by mass or more, and most preferably 99.95% by mass or more, based on the above TFE-based polymer composition.

[0137] The TFE-based polymer composition (1) of the present disclosure may contain a fluorine-containing compound having a hydrophilic group.

[0138] Examples of the above hydrophilic group include -SO3M a , -SO2M a , -OSO2M a , -PO3M a , -COOM a , -OCOM a , and -OM a (In the formula, M a is -H, a metal atom, -NR 1 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, and R 1 is H or an organic group.) At least one selected from the group consisting of these is mentioned. The above hydrophilic group may be an ionic group, and is preferably an anionic group.

[0139] Examples of the fluorine-containing compound having a hydrophilic group include a fluorine-containing compound having a hydrophilic group with a molecular weight of 1000 or less, that is, a fluorine-containing compound having a hydrophilic group with a molecular weight of 1000 g / mol or less. The molecular weight of the above fluorine-containing compound is preferably 800 or less, and more preferably 500 or less. In the polymer particles obtained by polymerization carried out in the presence of a fluorine-containing surfactant, in addition to the TFE-based polymer, it is normal for the fluorine-containing surfactant to be contained. In this specification, the fluorine-containing surfactant is the one used during polymerization. The fluorine-containing compound having a molecular weight of 1000 or less may be a compound that is not added during polymerization, for example, a compound that is by-produced during the polymerization. In addition, when the fluorine-containing compound having a molecular weight of 1000 or less contains an anionic part and a cationic part, it means a fluorine-containing compound in which the molecular weight of the anionic part is 1000 or less. It is assumed that the TFE-based polymer is not included in the fluorine-containing compound having a molecular weight of 1000 or less.

[0140] Examples of the fluorine-containing compound having a hydrophilic group with a molecular weight of 1000 or less include surfactants containing fluorine (anionic fluorine-containing surfactants) in which the molecular weight of the anionic part is 1000 or less. The above-mentioned "anionic part" means the part excluding the cation of the above-mentioned fluorine-containing surfactant. For example, in the case of F(CF2) n1 COOM, it is the part of "F(CF2) n1 COO".

[0141] Examples of the anionic fluorine-containing surfactant include the general formula (N 0 ): X n0 -Rf n0 -Y 0 (N 0 ) (In the formula, X n0 is H, Cl or F. Rf n0 is an alkylene group having 3 to 20 carbon atoms, which is linear, branched or cyclic, and in which some or all of the H are substituted by F. The alkylene group may contain one or more ether bonds, and some of the H may be substituted by Cl. Y 0 is an anionic group.) Compounds represented by the formula are included.

[0142] Y 0The anionic group may be -COOM, -SO2M, or -SO3M, and may be -COOM or -SO3M. M is H, a metal atom, NR 7 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, and R 7 is H or an organic group. Examples of the above metal atom include an alkali metal (Group 1), an alkaline earth metal (Group 2), etc., and for example, Na, K or Li. R 7 may be H or an organic group of C 1-10 and may be H or an organic group of C 1-4 and may be H or an organic group of C 1-4 which may be an alkyl group. M may be H, a metal atom or NR 7 4, and may be H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 7 4, and may be H, Na, K, Li or NH4. The above Rf n0 may be one in which 50% or more of H is substituted with fluorine.

[0143] Examples of the compound represented by the general formula (N 0 ) include the general formula (N 1 ): X n0 -(CF2) m1 -Y 0 (N 1 ) (wherein X n0 is H, Cl and F, m1 is an integer of 3 to 15, and Y 0 is as defined above.) The compound represented by, the general formula (N 2 ): Rf n1 -O-(CF(CF3)CF2O) m2 CFX n1 -Y 0 (N 2 ) (wherein Rf n1 is a perfluoroalkyl group having 1 to 5 carbon atoms, m2 is an integer of 0 to 3, X n1 is F or CF3, and Y 0is as defined above. A compound represented by the general formula (N 3 ): Rf n2 (CH2) m3 -(Rf n3 ) q -Y 0 (N 3 ) (In the formula, Rf n2 is a partially or fully fluorinated alkyl group that may contain an ether bond with 1 to 13 carbon atoms, m3 is an integer from 1 to 3, Rf n3 is a linear or branched perfluoroalkylene group with 1 to 3 carbon atoms, q is 0 or 1, and Y 0 is as defined above. A compound represented by the general formula (N 4 ): Rf n4 -O-(CY n1 Y n2 ) p CF2-Y 0 (N 4 ) (In the formula, Rf n4 is a linear or branched partially or fully fluorinated alkyl group that may contain an ether bond and / or a chlorine atom with 1 to 12 carbon atoms, Y n1 and Y n2 are the same or different and are H or F, p is 0 or 1, and Y 0 is as defined above. A compound represented by the general formula (N 5 ): [Chemical formula] (In the formula, X n2 , X n3 and X n4 may be the same or different and are H, F, or a linear or branched partially or fully fluorinated alkyl group that may contain an ether bond with 1 to 6 carbon atoms. Rf n5 is a linear or branched partially or fully fluorinated alkylene group that may contain an ether bond with 1 to 3 carbon atoms, L is a linking group, and Y 0 is as defined above. However, Xn2 , X n3 , X n4 and Rf n5 The total carbon number of is 18 or less. Compounds represented by ) etc. can be mentioned.

[0144] More specifically, as the compound represented by the general formula (N 0 ), perfluorocarboxylic acid (I) represented by general formula (I), ω-H perfluorocarboxylic acid (II) represented by general formula (II), perfluoroether carboxylic acid (III) represented by general formula (III), perfluoroalkyl alkylene carboxylic acid (IV) represented by general formula (IV), perfluoroalkoxyfluorocarboxylic acid (V) represented by general formula (V), perfluoroalkylsulfonic acid (VI) represented by general formula (VI), ω-H perfluorosulfonic acid (VII) represented by general formula (VII), perfluoroalkyl alkylene sulfonic acid (VIII) represented by general formula (VIII), alkyl alkylene carboxylic acid (IX) represented by general formula (IX), fluorocarboxylic acid (X) represented by general formula (X), alkoxyfluorosulfonic acid (XI) represented by general formula (XI), compound (XII) represented by general formula (XII), compound (XIII) represented by the following general formula (XIII), etc. can be mentioned.

[0145] The above perfluorocarboxylic acid (I) is represented by the general formula (I): F(CF2) n1 COOM (I) (In the formula, n1 is an integer from 3 to 14, and M is H, a metal atom, NR 7 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, and R 7 is H or an organic group.)

[0146] The above ω-H perfluorocarboxylic acid (II) is represented by the general formula (II): H(CF2) n2 COOM (II) (In the formula, n2 is an integer from 4 to 15, and M is as defined above.) It is represented by

[0147] The above perfluoroether carboxylic acid (III) has the general formula (III): Rf 1 -O-(CF(CF3)CF2O) n3 CF(CF3)COOM (III) (In the formula, Rf 1 is a perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer from 0 to 3, and M is as defined above.) It is represented by

[0148] The above perfluoroalkyl alkylene carboxylic acid (IV) has the general formula (IV): Rf 2 (CH2) n4 Rf 3 COOM (IV) (In the formula, Rf 2 is a perfluoroalkyl group having 1 to 5 carbon atoms, Rf 3 is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, n4 is an integer from 1 to 3, and M is as defined above.) It is represented by

[0149] The above alkoxyfluorocarboxylic acid (V) has the general formula (V): Rf 4 -O-CY 1 Y 2 CF2-COOM (V) (In the formula, Rf 4 is a linear or branched partial or fully fluorinated alkyl group which may contain an ether bond and / or a chlorine atom having 1 to 12 carbon atoms, Y 1 and Y 2 are the same or different and are H or F, and M is as defined above.) It is represented by

[0150] The above perfluoroalkyl sulfonic acid (VI) has the general formula (VI): F(CF2) n5SO3M (VI) (wherein n5 is an integer of 3 to 14, and M is as defined above.)

[0151] The above ω-H perfluorosulfonic acid (VII) has the general formula (VII): H(CF2) n6 SO3M (VII) (wherein n6 is an integer of 4 to 14, and M is as defined above.)

[0152] The above perfluoroalkylalkylene sulfonic acid (VIII) has the general formula (VIII): Rf 5 (CH2) n7 SO3M (VIII) (wherein Rf 5 is a perfluoroalkyl group having 1 to 13 carbon atoms, n7 is an integer of 1 to 3, and M is as defined above.)

[0153] The above alkylalkylene carboxylic acid (IX) has the general formula (IX): Rf 6 (CH2) n8 COOM (IX) (wherein Rf 6 is a linear or branched or fully fluorinated alkyl group which may contain an ether bond having 1 to 13 carbon atoms, n8 is an integer of 1 to 3, and M is as defined above.)

[0154] The above fluorocarboxylic acid (X) has the general formula (X): Rf 7 -O-Rf 8 -O-CF2-COOM (X) (wherein Rf 7 is a linear or branched or fully fluorinated alkyl group which may contain an ether bond and / or a chlorine atom having 1 to 6 carbon atoms, Rf 8is a linear or branched, partial or fully fluorinated alkyl group having 1 to 6 carbon atoms, and M is as defined above.) is represented by

[0155] The above alkoxyfluorosulfonic acid (XI) has the general formula (XI): Rf 9 -O-CY 1 Y 2 CF2-SO3M (XI) (wherein Rf 9 is a linear or branched, partial or fully fluorinated alkyl group which may contain an ether bond having 1 to 12 carbon atoms and may contain chlorine, Y 1 and Y 2 are the same or different and are H or F, and M is as defined above.) is represented by

[0156] The above compound (XII) has the general formula (XII):

Chemical formula

[0157] The above compound (XIII) has the following general formula (XIII): Rf 11 -O-(CF2CF(CF3)O) n9(CF2O) n10 CF2COOM (XIII) (wherein, Rf 11 is a fluoroalkyl group having 1 to 5 carbon atoms and containing chlorine, n9 is an integer of 0 to 3, n10 is an integer of 0 to 3, and M is as defined above.) It is represented by. As the compound (XIII), CF2ClO(CF2CF(CF3)O) n9 (CF2O) n10 CF2COONH4 (a mixture with an average molecular weight of 750, wherein n9 and n10 are as defined above.) can be mentioned.

[0158] Thus, examples of the anionic fluorine-containing surfactant include carboxylic acid surfactants and sulfonic acid surfactants.

[0159] The fluorine-containing surfactant may be a single fluorine-containing surfactant or a mixture containing two or more fluorine-containing surfactants.

[0160] Examples of the fluorine-containing surfactant include compounds represented by the following formulas. The fluorine-containing surfactant may be a mixture of these compounds. F(CF2)7COOM, F(CF2)5COOM, H(CF2)6COOM, H(CF2)7COOM, CF3O(CF2)3OCHFCF2COOM, C3F7OCF(CF3)CF2OCF(CF3)COOM, CF3CF2CF2OCF(CF3)COOM, CF3CF2OCF2CF2OCF2COOM, C2F5OCF(CF3)CF2OCF(CF3)COOM, CF3OCF(CF3)CF2OCF(CF3)COOM, CF2ClCF2CF2OCF(CF3)CF2OCF2COOM, CF2ClCF2CF2OCF2CF(CF3)OCF2COOM, CF2ClCF(CF3)OCF(CF3)CF2OCF2COOM, CF2ClCF(CF3)OCF2CF(CF3)OCF2COOM, and, [Chemical formula] (In each formula, M is H, a metal atom, NR 7 4, imidazolium which may have a substituent, pyridinium which may have a substituent or phosphonium which may have a substituent. R 7 is H or an organic group.).

[0161] In the above formulas, M may be H, a metal atom or NR 7 4, and may be H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 7 4, and may be H, Na, K, Li or NH4. R 7 is H or an organic group of C 1-10 and may be H or an organic group of C 1-4 and may be H or an organic group of C 1-4 and may be an alkyl group of.

[0162] The content of the above anionic fluorine-containing surfactant is preferably 25 mass ppb or less, more preferably 20 mass ppb or less, still more preferably 15 mass ppb or less, still more preferably 10 mass ppb or less, still more preferably less than 10 mass ppb, still more preferably 1 mass ppb or less, still more preferably less than 1 mass ppb, and particularly preferably less than the quantification lower limit with respect to the above TFE-based polymer composition. The lower limit is not particularly limited and may be an amount less than the quantification lower limit.

[0163] The amount of the above anionic fluorine-containing surfactant is measured by the following method. Weigh 1 g of the sample, add 10 g (12.6 ml) of methanol, perform ultrasonic treatment for 60 minutes to obtain an extract. Appropriately concentrate the obtained extract by nitrogen purging, and measure the fluorine-containing compound in the concentrated extract by LC / MS / MS. Extract the molecular weight information from the obtained LC / MS spectrum, and confirm the match with the structural formula of the candidate fluorine-containing compound. Prepare aqueous solutions of the standard substance with a content of 5 levels or more, perform LC / MS analysis on the aqueous solutions of each content, plot the relationship between the content and the area of the area corresponding to the content, and draw a calibration curve. Using the above calibration curve, convert the area of the LC / MS chromatogram of the fluorine-containing compound in the extract into the content of the fluorine-containing compound. Note that the lower limit of quantification in this measurement method is 10 mass ppb.

[0164] The TFE-based polymer composition containing an anionic fluorine-containing surfactant can be obtained, for example, by polymerization using an anionic fluorine-containing surfactant.

[0165] Examples of the fluorine-containing compound having a hydrophilic group with a molecular weight of 1000 or less include a compound represented by the following general formula (1) (hereinafter also referred to as compound (1)). General formula (1): (H-(CF2) m-1 -COO) p M 1 (In the formula, m is 4 to 20. M 1 is H, a metal atom, NR 5 4 (R 5 may be the same or different, and is H or an organic group having 1 to 10 carbon atoms), an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent. p is 1 or 2.)

[0166] M 1 Examples of the metal atom as M include monovalent and divalent metal atoms, and examples include alkali metals (Group 1) or alkaline earth metals (Group 2), and specifically, Na, K, Li, etc. are exemplified. The four Rs 5 may be the same or different. R5 is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms.

[0167] In the general formula (1), m is preferably 6 or more, more preferably 8 or more, still more preferably 11 or more, still more preferably 13 or more, particularly preferably 15 or more, and preferably 18 or less, more preferably 16 or less.

[0168] The TFE-based polymer composition (1) of the present disclosure may contain one or more of the compound (1), or may contain two or more, or may contain three or more.

[0169] The content of the compound (1) (when two or more are present, the content for each component) may be 10 mass ppm or less, preferably 5000 mass ppb or less, more preferably 1000 mass ppb or less, still more preferably 500 mass ppb or less, still more preferably 100 mass ppb or less, still more preferably 50 mass ppb or less, still more preferably 25 mass ppb or less, and particularly preferably 10 mass ppb or less with respect to the above TFE-based polymer. The lower limit is not particularly limited, but may be 0.1 mass ppb or may be 1 mass ppb.

[0170] Examples of the fluorine-containing compound having a hydrophilic group with a molecular weight of 1000 or less include a compound represented by the following general formula (2) (hereinafter, also referred to as compound (2)). General formula (2): (H-(CF2) n -SO3) q M 2 (In the formula, n is 4 to 20. M 2 is H, a metal atom, NR 5 4 (R 5 is the same as above), an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent. q is 1 or 2.)

[0171] M 2 Examples of the metal atom as M include monovalent and divalent metal atoms, such as alkali metals (Group 1) or alkaline earth metals (Group 2), and specifically, Na, K, Li, etc. are exemplified. Four Rs 5 may be the same or different. R 5 is preferably 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.

[0172] In the general formula (2), n is preferably 6 or more, more preferably 8 or more, still more preferably 11 or more, even more preferably 13 or more, particularly preferably 15 or more, and preferably 18 or less, more preferably 16 or less.

[0173] The TFE-based polymer composition (1) of the present disclosure may contain one or more compounds (2), or may contain two or more compounds (2), or may contain three or more compounds (2).

[0174] The content of the compound (2) (when two or more are present, the content for each component) may be 10 mass ppm or less with respect to the above TFE-based polymer, preferably 5000 mass ppb or less, more preferably 1000 mass ppb or less, still more preferably 500 mass ppb or less, even more preferably 100 mass ppb or less, still more preferably 50 mass ppb or less, still more preferably 25 mass ppb or less, still more preferably 10 mass ppb or less, still more preferably 1 mass ppb or less, still more preferably less than 1 mass ppb, and particularly preferably less than the quantification lower limit. The lower limit is not particularly limited and may be an amount less than the quantification lower limit.

[0175] The TFE-based polymer composition containing compound (1) and / or (2) is obtained by using a hydrocarbon-based surfactant. The TFE-based polymer composition (1) of the present disclosure may contain a hydrocarbon-based surfactant together with the TFE-based polymer and compound (1) and / or (2). The content of the hydrocarbon-based surfactant in the above TFE-based polymer composition is not particularly limited, but is usually 100 mass ppm to 10 mass%. It is preferable that, among the hydrogen atoms bonded to the carbon atoms of the above hydrocarbon-based surfactant, the proportion substituted with fluorine atoms is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0176] The TFE-based polymer composition (1) of the present disclosure preferably contains compound (1) and / or (2), and is preferably obtained by polymerization using a hydrocarbon-based surfactant.

[0177] The TFE-based polymer composition (1) of the present disclosure preferably does not substantially contain a compound represented by the following general formula (3) (hereinafter also referred to as compound (3)). General formula (3): (H-(CF2)8-SO3) q M 2 (wherein M 2 is H, a metal atom, NR 5 4 (R 5 may be the same or different and is H or an organic group having 1 to 10 carbon atoms (preferably an organic group not containing fluorine), an imidazolium optionally having a substituent, a pyridinium optionally having a substituent, or a phosphonium optionally having a substituent. q is 1 or 2.)

[0178] Substantially free of compound (3) means that the content of compound (3) is 25 mass ppb or less with respect to the above TFE-based polymer. The content of compound (3) is preferably 20 mass ppb or less, more preferably 15 mass ppb or less, and still more preferably 10 mass ppb or less with respect to the above TFE-based polymer. The lower limit is not particularly limited and may be 0 mass ppb, may be 0.1 mass ppb, or may be 1 mass ppb.

[0179] The contents of compounds (1), (2) and (3) are values measured by liquid chromatography mass spectrometry as described in the examples described later.

[0180] The TFE-based polymer composition (1) of the present disclosure preferably contains substantially no water. Thereby, generation of gas and deterioration of electrochemical device characteristics can be suppressed. In addition, since the electrode active material and solid electrolyte to be combined can be widely selected, it is advantageous in the production process. Substantially free of water means that the water content with respect to the above TFE-based polymer composition is 0.010 mass% or less. The above water content is preferably 0.005 mass% or less, more preferably 0.003 mass% or less, still more preferably 0.002 mass% or less, and even more preferably 0.001 mass% or less. The above water content is measured by the following method. Measure the mass of the TFE-based polymer composition before and after heating at 150 ° C for 2 hours, and calculate according to the following formula. Take the sample three times, calculate each time, then find the average, and adopt the average value. Water content (mass%) = [(mass of TFE-based polymer composition before heating (g))-(mass of TFE-based polymer composition after heating (g))] / (mass of TFE-based polymer composition before heating (g)) × 100

[0181] The TFE-based polymer composition (1) of the present disclosure has fibrillating ability. The fibrillating ability refers to the property of being easily fibrillated by a shearing force to form fibrils. Since the TFE-based polymer composition having fibrillating ability can be paste-extruded and the TFE-based polymer composition not having fibrillating ability cannot be paste-extruded, whether the TFE-based polymer composition has fibrillating ability or not can be determined based on whether the composition can be paste-extruded or not. Specifically, it is determined by the following method. Mix 60 g of the TFE-based polymer composition and 12.3 g of hydrocarbon oil (trade name: Isopar G (registered trademark), manufactured by ExxonMobil) as an extrusion aid in a polyethylene container for 3 minutes. Fill the cylinder of the extruder with the above mixture at room temperature (25 ± 2°C), apply a load of 0.47 MPa to the piston inserted into the cylinder, and hold for 1 minute. Next, extrude from the orifice at a ram speed of 20 mm / min. The ratio of the cross-sectional area of the cylinder to the cross-sectional area of the orifice is 100. At this time, if the beads are broken and cannot be continuously extruded, it is judged that there is no fibrillating ability (cannot be paste-extruded), and if the beads are not broken and can be continuously extruded, it is judged that there is fibrillating ability (can be paste-extruded).

[0182] The TFE-based polymer composition (1) of the present disclosure is preferably non-melt processable.

[0183] The TFE-based polymer composition (1) of the present disclosure may have a 1.0% mass loss temperature of 492°C or lower. A TFE-based polymer composition having a 1.0% mass loss temperature of 492°C or lower is obtained by using a hydrocarbon-based surfactant. The above 1.0% mass loss temperature is a value measured by the following method. Precisely weigh about 10 mg of the TFE-based polymer composition without a heating history at a temperature of 300°C or higher, store it in a dedicated aluminum pan, and measure TG·DTA (simultaneous differential thermal and thermogravimetric analyzer). The 1.0% mass loss temperature is the temperature corresponding to the point where the weight has decreased by 1.0 mass% when the aluminum pan is heated from 25°C to 600°C at a rate of 10°C / min in an air atmosphere.

[0184] The TFE-based polymer composition (1) of the present disclosure may have a thermal stability index (TII) of 20 or more. A TFE-based polymer composition having a TII of 20 or more can be obtained by using a hydrocarbon surfactant. The TII is preferably 25 or more, more preferably 30 or more, still more preferably 35 or more, and particularly preferably 40 or more. The TII is also preferably 50 or less. The above TII is measured in accordance with ASTM D 4895-89.

[0185] The TFE-based polymer composition (1) of the present disclosure preferably has an endothermic peak temperature of 327 °C or higher, more preferably 330 °C or higher, still more preferably 333 °C or higher, still more preferably 335 °C or higher, still more preferably 337 °C or higher, particularly preferably 340 °C or higher, and also preferably 350 °C or lower, more preferably 346 °C or lower, in that it can form a sizing sheet with even better strength. The above endothermic peak temperature is the temperature corresponding to the minimum point in the melting heat curve obtained by performing differential scanning calorimetry [DSC] at a heating rate of 10 °C / min for a TFE-based polymer composition that has no history of being heated to a temperature of 300 °C or higher. When there are two or more minimum points in one melting peak, each is taken as the endothermic peak temperature.

[0186] The TFE-based polymer composition (1) of the present disclosure preferably has a melting point of 315 °C or higher, more preferably 320 °C or higher, still more preferably 323 °C or higher, still more preferably 325 °C or higher, and also preferably 335 °C or lower, more preferably 330 °C or lower, in that it can form a sizing sheet with even better strength. The above melting point is the temperature corresponding to the minimum point in the melting heat curve obtained by performing differential scanning calorimetry [DSC] at a heating rate of 10 °C / min for a TFE-based polymer composition that has a history of being heated to a temperature of 300 °C or higher.

[0187] The TFE-based polymer composition (1) of the present disclosure preferably has a standard specific gravity (SSG) of 2.280 or less, more preferably 2.250 or less, still more preferably 2.220 or less, even more preferably 2.200 or less, even more preferably 2.190 or less, particularly preferably 2.180 or less, and especially preferably 2.170 or less, in that it can form a composite sheet with even better strength. The above SSG is preferably also 2.130 or more. The above SSG is measured by the water displacement method in accordance with ASTM D 792 using a sample molded in accordance with ASTM D 4895 89.

[0188] The TFE-based polymer composition (1) of the present disclosure may have an average secondary particle size of 350 μm or more, preferably 400 μm or more, more preferably 450 μm or more, and preferably 1000 μm or less, more preferably 900 μm or less, still more preferably 800 μm or less, even more preferably 700 μm or less, and particularly preferably 600 μm or less. The above average secondary particle size is measured in accordance with JIS K 6891.

[0189] The TFE-based polymer composition (1) of the present disclosure preferably has an apparent density of 0.40 g / ml or more, more preferably 0.43 g / ml or more, and although the upper limit is not particularly limited, it may be 0.70 g / ml, in that it has excellent handleability. The above apparent density is measured in accordance with JIS K 6892.

[0190] The form of the TFE-based polymer composition (1) of the present disclosure is not limited, but it is preferably a powder in that it can be mixed with an electrode active material or a solid electrolyte without using a large amount of a dispersion medium. Note that the above TFE-based polymer composition may be in a form other than a powder, for example, it may be a dispersion.

[0191] The TFE-based polymer composition (1) of the present disclosure can be preferably produced by a production method including, for example, a step (A) of preparing an aqueous dispersion of a TFE-based polymer, a step (B) of coagulating the aqueous dispersion to obtain a wet powder, and a step (C) of drying the wet powder.

[0192] Step (A) is preferably a step (A1) of obtaining an aqueous dispersion of a TFE-based polymer by emulsion polymerization of TFE and a monomer having a polar group in an aqueous medium in the presence of an anionic fluorine-containing surfactant.

[0193] The emulsion polymerization in step (A1) can be carried out by a known method. For example, by carrying out emulsion polymerization of the monomers necessary to form the TFE-based polymer in an aqueous medium in the presence of an anionic fluorine-containing surfactant and a polymerization initiator, an aqueous dispersion containing particles (primary particles) of the TFE-based polymer is obtained. In the above emulsion polymerization, a chain transfer agent, a buffer, a pH adjuster, a co-stabilizer, a dispersion stabilizer, a radical scavenger, etc. may be used as necessary.

[0194] The above emulsion polymerization can be carried out, for example, in an aqueous medium in the presence of an anionic fluorine-containing surfactant and a polymerization initiator. The above emulsion polymerization can be carried out by charging an aqueous medium, the above anionic fluorine-containing surfactant, monomers and other additives as necessary into a polymerization reactor, stirring the contents of the reactor, maintaining the reactor at a predetermined polymerization temperature, then adding a predetermined amount of a polymerization initiator, and starting the polymerization reaction. After the start of the polymerization reaction, monomers, a polymerization initiator, a chain transfer agent, the above surfactant, etc. may be additionally added according to the purpose.

[0195] The above polymerization initiator is not particularly limited as long as it can generate radicals in the polymerization temperature range, and known oil-soluble and / or water-soluble polymerization initiators can be used. Furthermore, polymerization can also be started as a redox in combination with a reducing agent or the like. The concentration of the above polymerization initiator is appropriately determined according to the type of monomer, the molecular weight of the target TFE-based polymer, and the reaction rate.

[0196] As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

[0197] The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, such as dialkyl peroxydicarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate, peroxyesters such as t-butyl peroxyisobutyrate and t-butyl peroxypivalate, and dialkyl peroxides such as di-t-butyl peroxide. Also, di(ω-hydroxy-dodecafluorooctanoyl) peroxide, di(ω-hydroxy-tetradecafluoroheptanoyl) peroxide, di(ω-hydroxy-hexadecafluorononanoyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluorovaleryl) peroxide, di(perfluorohexanoyl) peroxide, di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide, di(perfluorononanoyl) peroxide, di(ω-chloro-hexafluorobutyryl) peroxide, di(ω-chloro-decafluorohexanoyl) peroxide, di(ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydroxy-dodecafluorooctanoyl-ω-hydroxy-hexadecafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydroxy-dodecafluorooctanoyl-perfluorobutyryl-peroxide, di(dichloropentafluorobutanoyl) peroxide, di(trichlorooctafluorohexanoyl) peroxide, di(tetrachloroundecafluorooctanoyl) peroxide, di(pentachlorotetradecafluorodecanoyl) peroxide, di(undecachlorodotriacontapentafluorodocosanoyl) peroxide, and di[perfluoro(or fluorochloro)acyl] peroxides are typical examples.

[0198] The water-soluble radical polymerization initiator may be a known water-soluble peroxide. For example, ammonium salts, potassium salts, sodium salts of persulfuric acid, perboric acid, perchloric acid, phosphoric acid, percarbonic acid, etc., t-butyl permaleate, t-butyl hydroperoxide, succinic acid peroxide, etc. may be mentioned. Among them, ammonium persulfate and succinic acid peroxide are preferred. Reducing agents such as sulfites and sulfites may also be included, and the amount used may be 0.1 to 20 times that of the peroxide.

[0199] The addition amount of the water-soluble radical polymerization initiator is not particularly limited, but an amount (for example, several ppm with respect to the water concentration) that does not significantly reduce the polymerization rate may be added all at once, sequentially, or continuously at the initial stage of the polymerization. The upper limit is in a range where the reaction temperature may be increased while removing the heat of polymerization reaction from the equipment surface. A more preferable upper limit is a range where the heat of polymerization reaction can be removed from the equipment surface. In terms of easily obtaining each of the above physical properties, the addition amount of the polymerization initiator is preferably an amount corresponding to 0.1 ppm or more with respect to the aqueous medium, more preferably an amount corresponding to 1.0 ppm or more, and preferably an amount corresponding to 100 ppm or less, more preferably an amount corresponding to 10 ppm or less.

[0200] For example, when polymerization is carried out at a low temperature of 30 °C or lower, it is preferable to use a redox initiator that combines an oxidizing agent and a reducing agent as the polymerization initiator. Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, ammonium cerium nitrate, bromates, etc. Examples of the reducing agent include sulfites, bisulfites, bromates, diimines, oxalic acid, etc. Examples of the persulfate include ammonium persulfate and potassium persulfate. Examples of the sulfite include sodium sulfite and ammonium sulfite. In order to increase the decomposition rate of the initiator, it is also preferable to add a copper salt or an iron salt to the combination of the redox initiator. Examples of the copper salt include copper(II) sulfate, and examples of the iron salt include iron(II) sulfate.

[0201] As the redox initiator, it is preferable that the oxidizing agent is permanganic acid or its salt, persulfate, manganese triacetate, cerium(IV) salt, or bromic acid or its salt, and the reducing agent is a dicarboxylic acid or its salt, or diimine. More preferably, the oxidizing agent is permanganic acid or its salt, persulfate, or bromic acid or its salt, and the reducing agent is a dicarboxylic acid or its salt.

[0202] Examples of the redox initiator include combinations such as potassium permanganate / oxalic acid, potassium permanganate / ammonium oxalate, manganese triacetate / oxalic acid, manganese triacetate / ammonium oxalate, ammonium cerium nitrate / oxalic acid, and ammonium cerium nitrate / ammonium oxalate. When using a redox initiator, either the oxidizing agent or the reducing agent may be charged into the polymerization tank in advance, and then the other may be added continuously or intermittently to initiate the polymerization. For example, when using potassium permanganate / oxalic acid, it is preferable to charge oxalic acid into the polymerization tank and continuously add potassium permanganate thereto. In the redox initiator of this specification, when "potassium permanganate / oxalic acid" is described, it means the combination of potassium permanganate and oxalic acid. The same applies to other compounds.

[0203] The redox initiator is particularly preferably a combination of an oxidizing agent that is a salt and a reducing agent that is a salt. For example, the oxidizing agent that is a salt is more preferably at least one selected from the group consisting of persulfate, permanganate, cerium(IV) salt, and bromate, even more preferably permanganate, and particularly preferably potassium permanganate. Also, the reducing agent that is a salt is more preferably at least one selected from the group consisting of oxalate, malonate, succinate, glutarate, and bromate, even more preferably oxalate, and particularly preferably ammonium oxalate.

[0204] Specific examples of the redox initiator preferably include at least one selected from the group consisting of potassium permanganate / oxalic acid, potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, manganese triacetate / ammonium oxalate, and ammonium cerium nitrate / ammonium oxalate. More preferably, it is at least one selected from the group consisting of potassium permanganate / oxalic acid, potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, and ammonium cerium nitrate / ammonium oxalate. Even more preferably, it is potassium permanganate / oxalic acid.

[0205] When using a redox initiator, the oxidizing agent and the reducing agent may be added together at the initial stage of polymerization, or the reducing agent may be added together at the initial stage of polymerization and the oxidizing agent may be added continuously, or the oxidizing agent may be added together at the initial stage of polymerization and the reducing agent may be added continuously, or both the oxidizing agent and the reducing agent may be added continuously.

[0206] When adding one of the above redox polymerization initiators first and then adding the remaining one continuously at the initial stage of polymerization, it is preferable to gradually reduce the addition rate in order to obtain a TFE-based polymer with a low SSG. It is more preferable to stop the polymerization during the process. The preferable time to stop the addition is before 20 to 40% by mass of all the TFE consumed in the polymerization reaction is consumed.

[0207] When using a redox initiator as the polymerization initiator, for the aqueous medium, the addition amount of the oxidizing agent is preferably 0.1 ppm or more, more preferably 0.3 ppm or more, still more preferably 0.5 ppm or more, even more preferably 1 ppm or more, particularly preferably 5 ppm or more, and extremely preferably 10 ppm or more. Also, it is preferably 10000 ppm or less, more preferably 1000 ppm or less, still more preferably 100 ppm or less, and even more preferably 50 ppm or less. The addition amount of the reducing agent is preferably 0.1 ppm or more, more preferably 1.0 ppm or more, still more preferably 3 ppm or more, even more preferably 5 ppm or more, particularly preferably 10 ppm or more. Also, it is preferably 10000 ppm or less, more preferably 1000 ppm or less, still more preferably 100 ppm or less, and even more preferably 50 ppm or less. Also, when using a redox initiator in the above emulsion polymerization, the polymerization temperature is preferably 100 °C or lower, more preferably 95 °C or lower, and still more preferably 90 °C or lower. Also, it is preferably 10 °C or higher, more preferably 20 °C or higher, and still more preferably 30 °C or higher.

[0208] As the above polymerization initiator, a water-soluble radical polymerization initiator and a redox initiator are preferable in terms of easily obtaining the above-described physical properties.

[0209] The above aqueous medium is a reaction medium for carrying out the polymerization and means a liquid containing water. The above aqueous medium is not particularly limited as long as it contains water, and may contain water and, for example, a fluorine-free organic solvent such as alcohol, ether, or ketone, and / or a fluorine-containing organic solvent having a boiling point of 40 °C or lower.

[0210] In the above emulsion polymerization, a nucleating agent, a chain transfer agent, a buffer, a pH adjuster, a stabilization aid, a dispersion stabilizer, a radical scavenger, a decomposer of the polymerization initiator, a dicarboxylic acid, etc. may be used as necessary.

[0211] For the purpose of adjusting the particle size, it is preferable to carry out the above emulsion polymerization by adding a nucleating agent. It is preferable to add the nucleating agent before the start of the polymerization reaction. As the above nucleating agent, known ones can be used. For example, it is preferably at least one selected from the group consisting of fluoropolyethers, nonionic surfactants, and chain transfer agents, and more preferably a nonionic surfactant.

[0212] Examples of the above fluoropolyether include perfluoropolyether (PFPE) acid or its salt. The above perfluoropolyether (PFPE) acid or its salt may have an arbitrary chain structure in which oxygen atoms in the main chain of the molecule are separated by saturated fluorocarbon groups having 1 to 3 carbon atoms. Also, two or more kinds of fluorocarbon groups may be present in the molecule. A typical structure has a repeating unit represented by the following formula: (-CFCF3-CF2-O-) n (-CF2-CF2-CF2-O-) n (-CF2-CF2-O-) n -(-CF2-O-) m (-CF2-CFCF3-O-) n -(-CF2-O-) m

[0213] These structures are described by Kasai in J. Appl. Polymer Sci. 57, 797 (1995). As disclosed in this document, the above PFPE acid or its salt may have a carboxylic acid group or its salt at one or both ends. The above PFPE acid or its salt may also have a sulfonic acid, phosphonic acid group or their salts at one or both ends. Further, the above PFPE acid or its salt may have different groups at each end. For monofunctional PFPE, the other end of the molecule is usually perfluorinated, but may contain hydrogen or chlorine atoms. The above PFPE acid or its salt has at least two ether oxygens, preferably at least four ether oxygens, and even more preferably at least six ether oxygens. Preferably, at least one of the fluorocarbon groups separating the ether oxygens, more preferably at least two of such fluorocarbon groups, has two or three carbon atoms. Even more preferably, at least 50% of the fluorocarbon groups separating the ether oxygens have two or three carbon atoms. Also preferably, the above PFPE acid or its salt has a total of at least 15 carbon atoms. For example, the preferred minimum value of n or n + m in the above repeating unit structure is at least 5. Two or more of the above PFPE acids or their salts having an acid group at one or both ends can be used in the production method of the present disclosure. The above PFPE acid or its salt preferably has a number average molecular weight of less than 6000 g / mol.

[0214] In terms of being able to further increase the molecular weight of the TFE-based polymer and improve the strength of the binder sheet, the above emulsion polymerization is preferably carried out by adding a radical scavenger or a decomposer of the polymerization initiator. The above radical scavenger or decomposer of the polymerization initiator is preferably added after the start of the polymerization reaction, preferably before 10% by mass or more, preferably 20% by mass or more of all the TFE consumed in the polymerization reaction is polymerized, and also preferably before 50% by mass or less, preferably 40% by mass or less is polymerized. When performing the pressure reduction and subsequent pressure increase described later, it is preferably added thereafter.

[0215] As the radical scavenger, a compound that does not have restart ability after addition or chain transfer to free radicals in the polymerization system is used. Specifically, a compound that easily undergoes a chain transfer reaction with primary radicals or growing radicals and then generates stable radicals that do not react with monomers, or a compound that has a function of easily undergoing an addition reaction with primary radicals or growing radicals to generate stable radicals is used. What is generally called a chain transfer agent is characterized by its activity in terms of the chain transfer constant and the restart efficiency. Among chain transfer agents, those with a restart efficiency of almost 0% are called radical scavengers. The above radical scavenger can also be a compound having a chain transfer constant with TFE at the polymerization temperature larger than the polymerization rate constant and a restart efficiency of substantially zero %. "The restart efficiency is substantially zero %" means that the generated radicals are converted into stable radicals by the radical scavenger. Preferably, it is a compound having a chain transfer constant (Cs) with TFE at the polymerization temperature (= chain transfer rate constant (kc) / polymerization rate constant (kp)) greater than 0.1. For the above compound, it is more preferable that the chain transfer constant (Cs) is 0.5 or more, still more preferable that it is 1.0 or more, even more preferable that it is 5.0 or more, and particularly preferable that it is 10 or more.

[0216] As the above radical scavenger, for example, at least one selected from the group consisting of aromatic hydroxy compounds, aromatic amines, N,N - diethylhydroxylamine, quinone compounds, terpenes, thiocyanates, and cupric chloride (CuCl2) is preferable. Examples of the aromatic hydroxy compound include unsubstituted phenol, polyhydric phenol, salicylic acid, m - or p - salicylic acid, gallic acid, naphthol, and the like. Examples of the above unsubstituted phenol include о -, m - or p - nitrophenol, о -, m - or p - aminophenol, p - nitrosophenol, and the like. Examples of the polyhydric phenol include catechol, resorcinol, hydroquinone, pyrogallol, phloroglucin, naphthoresorcinol, and the like. Examples of the aromatic amines include o-, m- or p-phenylenediamine, benzidine and the like. Examples of the quinone compounds include o-, m- or p-benzoquinone, 1,4-naphthoquinone, alizarin and the like. Examples of the thiocyanates include ammonium thiocyanate (NH4SCN), potassium thiocyanate (KSCN), sodium thiocyanate (NaSCN) and the like. Among the above radical scavengers, aromatic hydroxy compounds are preferred, unsubstituted phenols or polyhydric phenols are more preferred, and hydroquinone is even more preferred.

[0217] From the viewpoint of moderately reducing the standard specific gravity, the addition amount of the above radical scavenger is preferably an amount corresponding to 3 to 500% (molar basis) of the polymerization initiator concentration. A more preferable lower limit is 10% (molar basis), and even more preferably 15% (molar basis). A more preferable upper limit is 400% (molar basis), and even more preferably 300% (molar basis).

[0218] The decomposer of the above polymerization initiator may be any compound that can decompose the used polymerization initiator. For example, at least one selected from the group consisting of sulfites, bisulfites, bromates, diimines, diimine salts, oxalic acid, oxalates, copper salts, and iron salts is preferred. Examples of the sulfites include sodium sulfite and ammonium sulfite. Examples of the copper salts include copper(II) sulfate, and examples of the iron salts include iron(II) sulfate. From the viewpoint of moderately reducing the standard specific gravity, the addition amount of the above decomposer is preferably an amount corresponding to 3 to 500% (molar basis) of the initiator concentration. A more preferable lower limit is 10% (molar basis), and even more preferably 15% (molar basis). A more preferable upper limit is 400% (molar basis), and even more preferably 300% (molar basis).

[0219] The above emulsion polymerization may be carried out in the presence of 5 to 500 ppm of dicarboxylic acid with respect to the aqueous medium in order to reduce the amount of coagulum generated during the polymerization, and it is preferably carried out in the presence of 10 to 200 ppm of dicarboxylic acid. If the above dicarboxylic acid is too little with respect to the aqueous medium, there is a risk that sufficient effects cannot be obtained. If it is too much, a chain transfer reaction may occur, and the resulting polymer may have a low molecular weight. More preferably, the above dicarboxylic acid is 150 ppm or less. The above dicarboxylic acid may be added before the start of the polymerization reaction or during the polymerization.

[0220] As the above dicarboxylic acid, for example, those represented by the general formula: HOOCRCOOH (wherein R represents an alkylene group having 1 to 5 carbon atoms) are preferable, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid are more preferable, and succinic acid is even more preferable.

[0221] In the above emulsion polymerization, the polymerization temperature and the polymerization pressure are appropriately determined according to the type of monomer used, the molecular weight of the target TFE-based polymer, and the reaction rate. Usually, the polymerization temperature is 5 to 150°C, preferably 10°C or higher, more preferably 30°C or higher, and even more preferably 50°C or higher. Also, more preferably, it is 120°C or lower, and even more preferably 100°C or lower. The polymerization pressure is 0.05 to 10 MPaG. More preferably, the polymerization pressure is 0.3 MPaG or higher, and even more preferably 0.5 MPaG or higher. Also, more preferably, it is 5.0 MPaG or lower, and even more preferably 3.0 MPaG or lower.

[0222] When using VDF as the modified monomer, in the above emulsion polymerization, in terms of easily obtaining each of the physical properties described above, the VDF concentration in the gas in the reactor at the start of polymerization (when the initiator is added) is preferably 0.001 mol% or more, and more preferably 0.01 mol% or more. The above concentration may also be 15 mol% or less, preferably 6.0 mol% or less, more preferably 5.0 mol% or less, even more preferably 3.0 mol% or less, and particularly preferably 1.0 mol% or less. The above VDF concentration may be maintained until the end of the polymerization reaction, or pressure reduction may be carried out during the process. VDF is preferably charged all at once before the start of polymerization, but a part thereof may be added continuously or intermittently after the start of polymerization.

[0223] When using VDF as the modified monomer, in the above emulsion polymerization, after charging VDF into the polymerization vessel, it is preferable not to perform pressure reduction until the polymerization is completed. Thereby, VDF can be left in the system until the end of polymerization, and the strength of the composite sheet using the obtained TFE-based polymer can be further increased.

[0224] When using HFP as the modified monomer, in the above emulsion polymerization, in terms of easily obtaining each of the physical properties described above, the HFP concentration in the gas in the reactor at the start of polymerization (when the initiator is added) is preferably 0.01 - 3.0 mol%. Further, when 40% by mass of all the TFE consumed in the polymerization reaction is polymerized, the HFP concentration in the gas in the reactor is preferably greater than 0 mol% and 0.2 mol% or less. The above HFP concentration is preferably maintained until the end of the polymerization reaction. HFP may be charged all at once before the start of polymerization, or a part thereof may be charged before the start of polymerization and continuously or intermittently added after the start of polymerization. By ensuring that HFP remains until the end of the polymerization reaction, although the strength of the composite sheet using the obtained TFE-based polymer is high, the extrusion pressure decreases.

[0225] When using HFP as the modified monomer, in the above emulsion polymerization, in terms of further improving the strength of the composite sheet using the obtained TFE-based polymer, it is preferable to depressurize before 5 to 40% by mass of the total TFE consumed in the polymerization reaction is polymerized, and then repressurize only with TFE. The above depressurization is preferably carried out so that the pressure in the reactor becomes 0.2 MPaG or less, more preferably so that it becomes 0.1 MPaG or less, and even more preferably so that it becomes 0.05 MPaG or less. Also, it is preferably carried out so that it becomes 0.0 MPaG or more. Also, the above depressurization and repressurization may be carried out multiple times. The depressurization may be carried out to a reduced pressure using a vacuum pump.

[0226] When using CTFE as the modified monomer, in the above emulsion polymerization, in terms of easily obtaining each of the above physical properties, it is preferable that the CTFE concentration in the gas in the reactor at the start of polymerization (when the initiator is added) is 0.001 mol% or more, and more preferably 0.01 mol% or more. The above concentration is preferably 3.0 mol% or less, and more preferably 1.0 mol% or less. The above CTFE concentration may be maintained until the end of the polymerization reaction, or depressurization may be carried out during the process. CTFE is preferably charged all at once before the start of polymerization, but a part may be added continuously or intermittently after the start of polymerization.

[0227] When using CTFE as the modified monomer, in the above emulsion polymerization, after charging CTFE into the polymerization vessel, it is preferable not to carry out depressurization until the polymerization is completed. Thereby, CTFE can be left in the system until the end of polymerization, and the strength of the composite sheet using the obtained TFE-based polymer can be further increased.

[0228] Step (A) is also preferably Step (A2) of obtaining an aqueous dispersion of a TFE-based polymer by emulsion polymerizing TFE and a monomer having a polar group in an aqueous medium in the presence of a hydrocarbon-based surfactant.

[0229] The hydrocarbon surfactant preferably has a proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms of 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0230] Step (A2) preferably includes a step of performing emulsion polymerization of only tetrafluoroethylene or emulsion polymerization of tetrafluoroethylene and a modified monomer copolymerizable with the tetrafluoroethylene in an aqueous medium in the presence of a specific hydrocarbon surfactant, and a step of continuously adding the specific hydrocarbon surfactant in the above step.

[0231] Continuous addition of the specific hydrocarbon surfactant means, for example, adding the specific hydrocarbon surfactant not all at once, but over time, without interruption or in portions. The specific hydrocarbon surfactant is, for example, a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group), or a hydrocarbon surfactant obtained by subjecting a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group) to radical treatment or oxidation treatment. The above radical treatment may be any treatment that generates radicals in a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group). For example, deionized water and a hydrocarbon surfactant are added to a reactor, the reactor is sealed, the system is replaced with nitrogen, the reactor is heated and pressurized, a polymerization initiator is charged, stirred for a certain period of time, and then the reactor is depressurized until it reaches atmospheric pressure and cooled. The above oxidation treatment is a treatment in which an oxidizing agent is added to a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group). Examples of the oxidizing agent include oxygen, ozone, hydrogen peroxide solution, manganese(IV) oxide, potassium permanganate, potassium dichromate, nitric acid, sulfur dioxide, and the like. By the above production method, a TFE-based polymer having a molecular weight equivalent to that of a production method using a conventional fluorine-containing surfactant can be produced without using a conventional fluorine-containing surfactant.

[0232] In the above manufacturing method, in the step of continuously adding the specific hydrocarbon-based surfactant, it is preferable that the addition of the hydrocarbon-based surfactant to the aqueous medium starts when the solid content of the TFE-based polymer formed in the aqueous medium is less than 0.60% by mass. When it is 0.5% by mass or less, it is preferable that the addition of the specific hydrocarbon-based surfactant to the aqueous medium starts. It is more preferable that the addition of the specific hydrocarbon-based surfactant starts when the solid content is 0.3% by mass or less, still more preferable when it is 0.2% by mass or less, even more preferable when it is 0.1% by mass or less, and particularly preferable to start adding at the same time as the polymerization initiation. The solid content is the concentration with respect to the total of the aqueous medium and the TFE-based polymer.

[0233] In the step of continuously adding the specific hydrocarbon-based surfactant, the addition amount of the specific hydrocarbon-based surfactant is preferably 0.01 to 10% by mass with respect to 100% by mass of the aqueous medium. A more preferable lower limit is 0.05% by mass, a still more preferable lower limit is 0.1% by mass, a more preferable upper limit is 5% by mass, and a still more preferable upper limit is 1% by mass.

[0234] In the step of performing emulsion polymerization of only tetrafluoroethylene or emulsion polymerization of tetrafluoroethylene and a modified monomer copolymerizable with the tetrafluoroethylene in an aqueous medium in the presence of the specific hydrocarbon-based surfactant, the amount of the specific hydrocarbon-based surfactant is preferably large, and is preferably 0.0001 to 10% by mass with respect to 100% by mass of the aqueous medium. A more preferable lower limit is 0.001% by mass, and a more preferable upper limit is 1% by mass. If it is less than 0.0001% by mass, the dispersing power may be insufficient, and if it exceeds 10% by mass, an effect commensurate with the amount cannot be obtained, and instead, the polymerization rate may decrease or the reaction may stop. The amount of the specific hydrocarbon-based surfactant is appropriately determined according to the type of monomer used, the molecular weight of the target TFE-based polymer, etc.

[0235] As the above-mentioned specific hydrocarbon surfactant, a surfactant represented by the formula: R-X (wherein R is a fluorine-free organic group having 1 to 2000 carbon atoms and having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group), and X is -OSO3X 1 , -COOX 1 or -SO3X 1 (X 1 is H, a metal atom, NR 1 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, and R 1 is H or an organic group (preferably an organic group not containing fluorine), and they may be the same or different.)) is preferred. R preferably has 500 or less carbon atoms, more preferably 100 or less carbon atoms, still more preferably 50 or less carbon atoms, and even more preferably 30 or less carbon atoms. As the above-mentioned specific hydrocarbon surfactant, the following formula (a): [Chemical formula] (wherein R 1a is 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 by a hydroxy group or a monovalent organic group containing an ester bond (preferably an organic group not containing fluorine), and when having 2 or more carbon atoms, it may contain a carbonyl group, and when having 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or form a ring. R 2a and R 3a are independently a single bond or a divalent linking group. R 1a , R 2a and R 3a have a total of 6 or more carbon atoms. X a is H, a metal atom, NR 4a 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, and R 4ais H or an organic group (preferably an organic group not containing fluorine), and they may be the same or different. R 1a , R 2a and R 3a Any two of them may be bonded to each other to form a ring. The surfactant (a) represented by the following formula (b):

Chemical formula

Chemical formula

[0236] The surfactant (a) will be described.

[0237] In formula (a), R 1a is 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 above alkyl group has 3 or more carbon atoms, it may contain a carbonyl group (-C(=O)-) between two carbon atoms. Also, when the above alkyl group has 2 or more carbon atoms, the carbonyl group can be included at the end of the above alkyl group. That is, an acyl group such as an acetyl group represented by CH3-C(=O)- is also included in the above alkyl group. In addition, when the above alkyl group has 3 or more carbon atoms, it can contain a monovalent or divalent heterocyclic ring, or can form a ring. As the above heterocyclic ring, an unsaturated heterocyclic ring is preferable, and an oxygen-containing unsaturated heterocyclic ring is more preferable, and examples thereof include a furan ring and the like. R 1a In, a divalent heterocyclic ring may be inserted between two carbon atoms, a divalent heterocyclic ring may be located at the end and bonded to -C(=O)-, or a monovalent heterocyclic ring may be located at the end of the above alkyl group.

[0238] In this specification, the "number of carbon atoms" of the above alkyl group includes the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the above heterocyclic ring. For example, a group represented by CH3-C(=O)-CH2- has 3 carbon atoms, a group represented by CH3-C(=O)-C2H4-C(=O)-C2H4- has 7 carbon atoms, and a group represented by CH3-C(=O)- has 2 carbon atoms.

[0239] The hydrogen atom bonded to the carbon atom of the above alkyl group may be substituted by a functional group. For example, it may be substituted by a hydroxy group (-OH) or a monovalent organic group containing an ester bond (preferably an organic group not containing fluorine), but it is preferable that it is not substituted by any functional group. As the monovalent organic group containing the above ester bond, the formula: -O-C(=O)-R 101a (wherein R 101a is an alkyl group) represents a group. The above alkyl group may have up to 75% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, may have up to 50% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, or may have up to 25% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms and chlorine atoms.

[0240] In the formula, R 2a and R 3a are each independently a single bond or a divalent linking group. R 2a and R 3a are each independently preferably a single bond or a linear or branched alkylene group having 1 or more carbon atoms or a cyclic alkylene group having 3 or more carbon atoms. R 2a and R 3a The above alkylene group constituting is preferably free of a carbonyl group.

[0241] The above alkylene group may have the hydrogen atoms bonded to the carbon atoms substituted by a functional group, for example, may be substituted by a hydroxy group (-OH) or a monovalent organic group containing an ester bond (preferably an organic group not containing fluorine), but is preferably not substituted by any functional group. Examples of the above monovalent organic group containing an ester bond include a group represented by the formula: -O-C(=O)-R 102a (In the formula, R 102a is an alkyl group). The above alkylene group may have up to 75% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, may have up to 50% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, or may have up to 25% of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, but is preferably a non-halogenated alkylene group that does not contain halogen atoms such as fluorine atoms and chlorine atoms.

[0242] R 1a 、R 2a and R 3aIt has a total carbon number of 6 or more. As the total carbon number, 8 or more is preferable, 9 or more is more preferable, 10 or more is even more preferable, 20 or less is preferable, 18 or less is more preferable, and 15 or less is even more preferable. R 1a 、R 2a and R 3a Any two of them may be bonded to each other to form a ring.

[0243] In formula (a), X a is H, a metal atom, NR 4a 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, and R 4a is H or an organic group (preferably an organic group not containing fluorine). The four Rs 4a may be the same or different. As the organic group in R 4a , an alkyl group is preferable. As R 4a , H or an organic group having 1 to 10 carbon atoms is preferable, H or an organic group having 1 to 4 carbon atoms is more preferable, and H or an alkyl group having 1 to 4 carbon atoms is even more preferable. Examples of the above metal atom include an alkali metal (Group 1), an alkaline earth metal (Group 2), etc., and Na, K or Li is preferable. X a is preferably H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 4a 4. Since it is easily soluble in water, H, Na, K, Li or NH4 is more preferable. Since it is even more easily soluble in water, Na, K or NH4 is even more preferable. Na or NH4 is particularly preferable. Since it is easily removable, NH4 is most preferable. When X a is NH4, the surfactant has excellent solubility in an aqueous medium, and it is difficult for a metal component to remain in the TFE-based polymer or the final product.

[0244] As the surfactant (a), the following surfactants can be exemplified. In each formula, X a is as described above.

[0245]

Chemical formula

[0246]

Chem.

[0247]

Chem.

[0248]

Chem.

[0249]

Chem.

[0250]

Chem.

[0251]

Chem.

[0252]

Chem.

[0253] The surfactant (a) can be produced, for example, by the production method described in International Publication No. 2020 / 022355.

[0254] Next, the surfactant (b) will be described.

[0255] In formula (b), R 1b is 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 above alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring, or may form a ring. As the above heterocyclic ring, an unsaturated heterocyclic ring is preferable, and an oxygen-containing unsaturated heterocyclic ring is more preferable. For example, a furan ring and the like can be mentioned. R 1b In, a divalent heterocyclic ring may be inserted between two carbon atoms, a divalent heterocyclic ring may be located at the terminal and bonded to -C(=O)-, or a monovalent heterocyclic ring may be located at the terminal of the above alkyl group.

[0256] In addition, in this specification, the "number of carbon atoms" of the above alkyl group shall include the number of carbon atoms constituting the above heterocyclic ring.

[0257] R 1b The above substituents that the above alkyl group as R may have are 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, a hydroxy group, and particularly preferably a methyl group and an ethyl group.

[0258] R 1b The above alkyl group as R preferably does not contain a carbonyl group. In the above alkyl group, 75% or less of the hydrogen atoms bonded to carbon atoms may be substituted by halogen atoms, 50% or less may be substituted by halogen atoms, 25% or less may be substituted by halogen atoms, but it is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms and chlorine atoms. The above alkyl group preferably does not have any substituents.

[0259] R 1bExamples thereof include a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms which may have a substituent. A linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms which does not contain a carbonyl group is more preferable. A linear or branched alkyl group having 1 to 10 carbon atoms which has no substituent is still more preferable. A linear or branched alkyl group having 1 to 3 carbon atoms which has no substituent is even more preferable. A methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferable, and a methyl group (-CH3) is most preferable.

[0260] In formula (b), R 2b and R 4b are each independently H or a substituent. A plurality of R 2b and R 4b may be the same or different from each other.

[0261] Examples of the above-mentioned substituent for R 2b and R 4b include 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, and a hydroxy group. A methyl group and an ethyl group are particularly preferable.

[0262] The above-mentioned alkyl group for R 2b and R 4b preferably does not contain a carbonyl group. Up to 75% of the hydrogen atoms bonded to the carbon atoms of the above-mentioned alkyl group may be substituted with halogen atoms, up to 50% may be substituted with halogen atoms, or up to 25% may be substituted with halogen atoms, but a non-halogenated alkyl group which does not contain halogen atoms such as fluorine atoms and chlorine atoms is preferable. The above-mentioned alkyl group preferably has no substituent.

[0263] R 2b and R 4bAs the above alkyl group, 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 is preferable, a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group is more preferable, a linear or branched alkyl group having 1 to 3 carbon atoms and not having a substituent is still more preferable, and a methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferable.

[0264] R 2b and R 4b are each independently preferably H or a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a linear or branched alkyl group having 1 to 3 carbon atoms and not having a substituent, still more preferably H, a methyl group (-CH3) or an ethyl group (-C2H5), and particularly preferably H.

[0265] In formula (b), R 3b is an alkylene group having 1 to 10 carbon atoms which may have a substituent. R 3b When there are a plurality of them, they may be the same or different.

[0266] The above alkylene group preferably does not contain a carbonyl group. In the above alkylene group, 75% or less of the hydrogen atoms bonded to the carbon atoms may be substituted by halogen atoms, 50% or less may be substituted by halogen atoms, 25% or less may be substituted by halogen atoms, but it is preferably a non-halogenated alkylene group not containing halogen atoms such as fluorine atoms and chlorine atoms. The above alkylene group preferably does not have any substituents.

[0267] As the alkylene group, a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent or a cyclic alkylene group having 3 to 10 carbon atoms which may have a substituent is preferable, a linear or branched alkylene group having 1 to 10 carbon atoms which does not contain a carbonyl group or a cyclic alkylene group having 3 to 10 carbon atoms which does not contain a carbonyl group is preferable, a linear or branched alkylene group having 1 to 10 carbon atoms which does not have a substituent is more preferable, and a methylene group (-CH2-), an ethylene group (-C2H4-), an isopropylene group (-CH(CH3)CH2-) or a propylene group (-C3H6-) is still more preferable.

[0268] R 1b 、R 2b 、R 3b and R 4b Any two of them may be bonded to each other to form a ring, but it is preferable that no ring is formed.

[0269] In formula (b), n is an integer of 1 or more. As n, an integer of 1 to 40 is preferable, an integer of 1 to 30 is more preferable, an integer of 5 to 25 is still more preferable, and an integer of 5 to 9, 11 to 25 is particularly preferable.

[0270] In formula (b), p and q are independently integers of 0 or more. As p, an integer of 0 to 10 is preferable, and 0 or 1 is more preferable. As q, an integer of 0 to 10 is preferable, and an integer of 0 to 5 is more preferable.

[0271] It is preferable that the total of n, p and q is an integer of 5 or more. It is more preferable that the total of n, p and q is an integer of 8 or more. The total of n, p and q is also 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.

[0272] In formula (b), X b is H, a metal atom, NR 5b 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent or a phosphonium which may have a substituent, and R 5bis H or an organic group (preferably an organic group not containing fluorine). The four Rs 5b may be the same or different. As the organic group in R 5b , an alkyl group is preferred. As R 5b , H or an organic group having 1 to 10 carbon atoms is preferred, H or an organic group having 1 to 4 carbon atoms is more preferred, and H or an alkyl group having 1 to 4 carbon atoms is still more preferred. Examples of the above metal atom include an alkali metal (Group 1), an alkaline earth metal (Group 2), etc., and Na, K or Li is preferred. X b is a metal atom or NR 5b 4 (R 5b is as described above) and may be. X b , as H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 5b 4 is preferred. Since it is easily soluble in water, H, Na, K, Li or NH4 is more preferred. Since it is even more easily soluble in water, Na, K or NH4 is still more preferred. Na or NH4 is particularly preferred. Since removal is easy, NH4 is most preferred. When X b is NH4, the surfactant has excellent solubility in an aqueous medium, and it is difficult for a metal component to remain in the TFE-based polymer or the final product.

[0273] In formula (b), L is a single bond, -CO2-B-*, -OCO-B-*, -CONR 6b -B-*, -NR 6b CO-B-*, or -CO- (however, excluding the carbonyl group contained in -CO2-B-, -OCO-B-, -CONR 6b -B-, -NR 6b CO-B-). B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent. R 6b is H or an alkyl group having 1 to 4 carbon atoms which may have a substituent. The above alkylene group preferably has 1 to 5 carbon atoms. Also, the above R 6b is preferably H or a methyl group. * indicates the side bonded to -OSO3X b in the formula.

[0274] L is preferably a single bond.

[0275] As the surfactant (b), the following formula:

Chemical formula

[0276] Examples of the surfactant (b) include CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2OSO3Na, (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2OSO3Na, CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2OSO3Na, CH3CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3H, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Li, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3K, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3NH4, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Na、 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3H, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Li, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3K, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3NH4, Examples include CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na and the like.

[0277] The surfactant (b) can be produced, for example, by the production method described in International Publication No. 2020 / 022355.

[0278] Next, the surfactant (c) will be described.

[0279] In formula (c), R 1c is 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 above alkyl group has 3 or more carbon atoms, it may contain a carbonyl group (-C(=O)-) between two carbon atoms. Further, when the above alkyl group has 2 or more carbon atoms, the above carbonyl group can also be included at the end of the above alkyl group. That is, an acyl group such as an acetyl group represented by CH3-C(=O)- is also included in the above alkyl group. In addition, when the above alkyl group has 3 or more carbon atoms, it can also contain a monovalent or divalent heterocyclic ring or can form a ring. As the above heterocyclic ring, an unsaturated heterocyclic ring is preferable, and an oxygen-containing unsaturated heterocyclic ring is more preferable. For example, a furan ring etc. are mentioned. R 1c In, a divalent heterocyclic ring may be inserted between two carbon atoms, a divalent heterocyclic ring may be located at the end and bonded to -C(=O)-, or a monovalent heterocyclic ring may be located at the end of the above alkyl group.

[0280] In this specification, the "number of carbon atoms" of the above alkyl group shall include the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the above heterocyclic ring. For example, the group represented by CH3-C(=O)-CH2- has 3 carbon atoms, the group represented by CH3-C(=O)-C2H4-C(=O)-C2H4- has 7 carbon atoms, and the group represented by CH3-C(=O)- has 2 carbon atoms.

[0281] The above alkyl group may have a hydrogen atom bonded to a carbon atom substituted by a functional group, for example, may be substituted by a hydroxy group (-OH) or a monovalent organic group containing an ester bond (preferably an organic group not containing fluorine), but it is preferably not substituted by any functional group. Examples of the monovalent organic group containing an ester bond include a group represented by the formula: -O-C(=O)-R 101c (wherein R 101c is an alkyl group). The above alkyl group may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted by halogen atoms, may have 50% or less substituted by halogen atoms, may have 25% or less substituted by halogen atoms, but is preferably a non-halogenated alkyl group not containing halogen atoms such as fluorine atoms and chlorine atoms.

[0282] In formula (c), R 2c and R 3c are each independently a single bond or a divalent linking group. R 2c and R 3c are each independently preferably a single bond or a linear or branched alkylene group having 1 or more carbon atoms or a cyclic alkylene group having 3 or more carbon atoms. R 2c and R 3c The above alkylene group constituting is preferably free of a carbonyl group.

[0283] The above alkylene group may have a hydrogen atom bonded to a carbon atom substituted by a functional group, for example, may be substituted by a hydroxy group (-OH) or a monovalent organic group containing an ester bond (preferably an organic group not containing fluorine), but it is preferably not substituted by any functional group. Examples of the monovalent organic group containing an ester bond include a group represented by the formula: -O-C(=O)-R 102c (wherein R 102c is an alkyl group). The alkylene group may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, 50% or less of the hydrogen atoms substituted with halogen atoms, or 25% or less of the hydrogen atoms substituted with halogen atoms, but is preferably a non-halogenated alkylene group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0284] R 1c , R 2c and R 3c has a total carbon number of 5 or more. The total carbon number is preferably 7 or more, more preferably 9 or more, and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. R 1c , R 2c and R 3c Any two of them may be bonded to each other to form a ring.

[0285] In formula (c), in formula, A c -COOX c or -SO3X c (X c is H, metal atom, NR 4c 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 4c R is H or an organic group (preferably an organic group not containing fluorine), and may be the same or different. 4c The organic group in R is preferably an alkyl group. 4c is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and further preferably H or an alkyl group having 1 to 4 carbon atoms. The metal atom includes alkali metals (Group 1), alkaline earth metals (Group 2), etc., and is preferably Na, K or Li. X c H, alkali metals (group 1), alkaline earth metals (group 2) or NR 4c4 is preferred, and since it is easily soluble in water, H, Na, K, Li or NH4 are more preferred. Since it is even more easily soluble in water, Na, K or NH4 are even more preferred. Na or NH4 are particularly preferred. Since removal is easy, NH4 is most preferred. X c When X is NH4, the surfactant has excellent solubility in the aqueous medium, and metal components are less likely to remain in the TFE-based polymer or the final product.

[0286] Examples of the surfactant (c) include the following surfactants. In each formula, A c is as described above.

[0287]

Chemical formula

[0288]

Chemical formula

[0289]

Chemical formula

[0290]

Chemical formula

[0291]

Chemical formula

[0292]

Chemical formula

[0293]

Chemical formula

[0294]

Chemical formula

[0295] The surfactant (c) can be produced, for example, by the production method described in International Publication No. 2020 / 022355.

[0296] Next, the surfactant (d) will be described.

[0297] In formula (d), R 1d is 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 above alkyl group has 3 or more carbon atoms, it can include a monovalent or divalent heterocyclic ring, or can form a ring. As the above heterocyclic ring, an unsaturated heterocyclic ring is preferable, and an oxygen-containing unsaturated heterocyclic ring is more preferable. For example, a furan ring and the like can be mentioned. In R 1d , a divalent heterocyclic ring may be inserted between two carbon atoms, a divalent heterocyclic ring may be located at the terminal and bonded to -C(=O)-, or a monovalent heterocyclic ring may be located at the terminal of the above alkyl group.

[0298] In this specification, the "number of carbon atoms" of the above alkyl group shall include the number of carbon atoms constituting the above heterocyclic ring.

[0299] R 1d The above substituents that the alkyl group as R may have are 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, a hydroxy group, and particularly preferably a methyl group and an ethyl group.

[0300] R 1d The above alkyl group as R preferably does not contain a carbonyl group. Up to 75% of the hydrogen atoms bonded to the carbon atoms of the alkyl group may be substituted by halogen atoms, up to 50% may be substituted by halogen atoms, and up to 25% may be substituted by halogen atoms, but it is preferably an unhalogenated alkyl group that does not contain halogen atoms such as fluorine atoms and chlorine atoms. The above alkyl group preferably has no substituents.

[0301] R 1d Preferably, it is a linear or branched alkyl group having 1 to 10 carbon atoms that may have substituents or a cyclic alkyl group having 3 to 10 carbon atoms that may have substituents. More preferably, it is a linear or branched alkyl group having 1 to 10 carbon atoms that does not contain a carbonyl group or a cyclic alkyl group having 3 to 10 carbon atoms that does not contain a carbonyl group. Even more preferably, it is a linear or branched alkyl group having 1 to 10 carbon atoms that has no substituents. Even more preferably, it is a linear or branched alkyl group having 1 to 3 carbon atoms that has no substituents. Particularly preferably, it is a methyl group (-CH3) or an ethyl group (-C2H5), and most preferably, it is a methyl group (-CH3).

[0302] In formula (d), R 2d and R 4d are each independently H or a substituent. A plurality of R 2d and R 4d may be the same or different from each other.

[0303] R 2d and R 4d As the above substituents, halogen atoms, linear or branched alkyl groups having 1 to 10 carbon atoms or cyclic alkyl groups having 3 to 10 carbon atoms, and hydroxy groups are preferable, and methyl groups and ethyl groups are particularly preferable.

[0304] R 2d and R 4d The above alkyl group preferably does not contain a carbonyl group. The above alkyl group may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted by halogen atoms, may have 50% or less of the hydrogen atoms bonded to carbon atoms substituted by halogen atoms, or may have 25% or less of the hydrogen atoms bonded to carbon atoms substituted by halogen atoms, but is preferably a non-halogenated alkyl group containing no halogen atoms such as fluorine atoms and chlorine atoms. The above alkyl group preferably has no substituents.

[0305] R 2d and R 4d As the above alkyl group, 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 is preferable, a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group is more preferable, a linear or branched alkyl group having 1 to 3 carbon atoms and having no substituents is still more preferable, and a methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferable.

[0306] R 2d and R 4d are each independently preferably H or a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a linear or branched alkyl group having 1 to 3 carbon atoms and having no substituents, still more preferably H, a methyl group (-CH3) or an ethyl group (-C2H5), and particularly preferably H.

[0307] In formula (d), R 3d is an alkylene group having 1 to 10 carbon atoms which may have substituents. When there are a plurality of R 3d , they may be the same or different.

[0308] The above alkylene group preferably does not contain a carbonyl group. The alkylene group may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, 50% or less of the hydrogen atoms substituted with halogen atoms, or 25% or less of the hydrogen atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkylene group preferably does not have any substituents.

[0309] The alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent, or a cyclic alkylene group having 3 to 10 carbon atoms which may have a substituent, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not contain a carbonyl group, or a cyclic alkylene group having 3 to 10 carbon atoms which does not contain a carbonyl group, and even more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not have a substituent, and even more preferably a methylene group (-CH2-), an ethylene group (-C2H4-), an isopropylene group (-CH(CH3)CH2-) or a propylene group (-C3H6-).

[0310] R 1d , R 2d , R 3d and R 4d Any two of them may be bonded to each other to form a ring.

[0311] In formula (d), n is an integer of 1 or more. As n, an integer of 1 to 40 is preferable, an integer of 1 to 30 is more preferable, and an integer of 5 to 25 is even more preferable.

[0312] In formula (d), p and q are independently an integer of 0 or more. p is preferably an integer of 0 to 10, and more preferably 0 or 1. q is preferably an integer of 0 to 10, and more preferably an integer of 0 to 5.

[0313] n, p, and q are preferably integers whose sum is 6 or more. More preferably, the sum of n, p, and q is an integer of 8 or more. The sum of n, p, and q is also 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.

[0314] In formula (d), A d is -SO3X d or -COOX d (X d is H, a metal atom, NR 5d 4, an optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, and R 5d is H or an organic group (preferably an organic group not containing fluorine), and they may be the same or different.) R 5d The organic group for R is preferably an alkyl group. R 5d is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and still more preferably H or an alkyl group having 1 to 4 carbon atoms. Examples of the above metal atom include alkali metals (Group 1), alkaline earth metals (Group 2), etc., and Na, K, or Li is preferred. X d is a metal atom or NR 5d 4 (R 5d is as described above). X d is preferably H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR 5d 4. Since it is easily soluble in water, H, Na, K, Li, or NH4 is more preferred. Since it is even more easily soluble in water, Na, K, or NH4 is still more preferred. Na or NH4 is particularly preferred. Since it is easily removed, NH4 is most preferred. When X d is NH4, the surfactant has excellent solubility in an aqueous medium, and it is difficult for metal components to remain in the TFE-based polymer or the final product.

[0315] In formula (d), L is a single bond, -CO2-B-*, -OCO-B-*, -CONR 6d -B-*, -NR6d CO-B-, or -CO- (provided that -CO2-B-, -OCO-B-, -CONR 6d -B-, -NR 6d excluding the carbonyl group contained in CO-B-.), where B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R 6d is 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. Also, the above R 6d is more preferably H or a methyl group. * refers to the side bonded to A in the formula. d

[0316] L is preferably a single bond.

[0317] Examples of the surfactant (d) include CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2COOK, CH3C(O)CH2CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, ​CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2COONa, CH3CH2CH2C(O)CH2CH2CH2CH2CH2CH2COONa, CH3CH2CH2CH2C(O)CH2CH2CH2CH2CH2COONa, CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2COONa, CH3CH2CH2CH2CH2CH2C(O)CH2CH2CH2COONa, CH3CH2CH2CH2CH2CH2CH2C(O)CH2CH2COONa, CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2COOK, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2COOK, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COOH, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COOLi, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONH4, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2C(CH3)2COOK, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2SO3Na, CH3C(O)CH2CH2SO3Na, CH3C(O)CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3H, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3K, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Li, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3NH4, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(CH3)2SO3Na etc. can be mentioned.

[0318] Surfactant (d) can be produced, for example, by the production method described in International Publication No. 2020 / 022355.

[0319] Next, surfactant (e) will be described.

[0320] In formula (e), R 1e ~R 5e represents H or a monovalent substituent, provided that at least one of R 1e and R 3e is a group represented by the general formula: -Y e -R 6e , at least one of R 2e and R 5e is a group represented by the general formula: -X e -A e , or a group represented by the general formula: -Y e -R 6e . Any two of R 1e ~R 5e may be bonded to each other to form a ring.

[0321] R 1eExamples of the substituent that the alkyl group may have include 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, a hydroxy group, with a methyl group or an ethyl group being particularly preferred.

[0322] R 1e The alkyl group is preferably free of a carbonyl group. Up to 75% of the hydrogen atoms bonded to the carbon atoms of the alkyl group may be substituted by halogen atoms, up to 50% may be substituted by halogen atoms, or up to 25% may be substituted by halogen atoms, but it is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms and chlorine atoms. The alkyl group preferably has no substituents.

[0323] R 1e Examples include a linear or branched alkyl group having 1 to 10 carbon atoms that may have a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms that may have a substituent, with a linear or branched alkyl group having 1 to 10 carbon atoms that does not contain a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms that does not contain a carbonyl group being more preferred, a linear or branched alkyl group having 1 to 10 carbon atoms that has no substituents being even more preferred, a linear or branched alkyl group having 1 to 3 carbon atoms that has no substituents being even more preferred, a methyl group (-CH3) or an ethyl group (-C2H5) being particularly preferred, and a methyl group (-CH3) being most preferred.

[0324] Examples of the monovalent substituent include a group represented by the general formula: -Y e -R 6e a group represented by the general formula: -X e -A e -H, an alkyl group of C 1-20 which may have a substituent, -NH2, -NHR 9e (R 9e is an organic group (preferably an organic group that does not contain fluorine)), -OH, -COOR 9e (R 9eis an organic group (preferably an organic group not containing fluorine) or -OR 9e (R 9e is preferably an organic group (preferably an organic group not containing fluorine). The number of carbon atoms of the above alkyl group is preferably 1 to 10.

[0325] R 9e is preferably an alkyl group of C 1-10 or an alkylcarbonyl group of C 1-10 More preferably, it is an alkyl group of C 1-4 or an alkylcarbonyl group of C 1-4 is more preferred.

[0326] In the formula, X e represents, in each occurrence, the same or different divalent linking group or a bond. R 6e When does not contain any of a carbonyl group, an ester group, an amide group and a sulfonyl group, X e is preferably a divalent linking group containing at least one selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group.

[0327] X e is preferably a divalent linking group containing at least one bond selected from the group consisting of -CO-, -S(=O)2-, -O-, -COO-, -OCO-, -S(=O)2-O-, -O-S(=O)2-, -CONR 8e -, and -NR 8e CO-, an alkylene group of C 1-10 or a bond. R 8e represents H or an organic group (preferably an organic group not containing fluorine).

[0328] R 8e The organic group in is preferably an alkyl group. R 8e is preferably H or an organic group of C 1-10 more preferably H or an organic group of C 1-4 even more preferably H or an alkyl group of C 1-4 and even more preferably H.

[0329] In formula (e), A e is, in each occurrence, the same or different, -COOM e , -SO3M e or -OSO3M e (M e is H, a metal atom, NR 7e 4, an optionally substituted imidazolium, an optionally substituted pyridinium or an optionally substituted phosphonium, R 7e is H or an organic group (preferably an organic group not containing fluorine). The four Rs 7e may be the same or different.). In formula (e), A e being -COOM e is one of the preferred embodiments.

[0330] As the organic group in R 7e , an alkyl group is preferred. As R 7e , H or a C 1-10 organic group is preferred, H or a C 1-4 organic group is more preferred, and H or a C 1-4 alkyl group is even more preferred. Examples of the above metal atom include an alkali metal (Group 1), an alkaline earth metal (Group 2), etc., and Na, K or Li is preferred.

[0331] As M e , H, a metal atom or NR 7e 4 is preferred, H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 7e 4 is more preferred, H, Na, K, Li or NH4 is even more preferred, Na, K or NH4 is even more preferably, Na or NH4 is particularly preferred, and NH4 is most preferred.

[0332] In formula (e), Y e is, in each occurrence, the same or different, a divalent linking group selected from the group consisting of -S(=O)2-, -O-, -COO-, -OCO-, -CONR 8e -, and -NR 8e CO-, or a bond, R 8erepresents H or an organic group (preferably an organic group not containing fluorine).

[0333] Y e As, a divalent linking group selected from the group consisting of a bond, -O-, -COO-, -OCO-, -CONR 8e -, and -NR 8e -CO- is preferred, and a divalent linking group selected from the group consisting of a bond, -COO- and -OCO- is more preferred.

[0334] R 8e The organic group in is preferably an alkyl group. R 8e As, H or a C 1-10 organic group is preferred, H or a C 1-4 organic group is more preferred, H or a C 1-4 alkyl group is even more preferred, and H is even more preferred.

[0335] In formula (e), R 6e represents, in each occurrence, the same or different, an alkyl group having 2 or more carbon atoms which may 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. The above R 6e The carbon number of the organic group (preferably an organic group not containing fluorine) is preferably 2 to 20, and more preferably 2 to 10.

[0336] R 6e The alkyl group of may 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 does not contain these groups at the terminal of the above alkyl group. The above R 6e The alkyl group of may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted by halogen atoms, may have 50% or less substituted by halogen atoms, may have 25% or less substituted by halogen atoms, but is preferably a non-halogenated alkyl group not containing halogen atoms such as fluorine atoms and chlorine atoms.

[0337] R 6e As, General formula: -R 10e -CO-R 11e a group represented by General formula: -R 10e -COO-R 11e a group represented by General formula: -R 11e a group represented by General formula: -R 10e -NR 8e CO-R 11e a group represented by, or General formula: -R 10e -CONR 8e -R 11e a group represented by (In the formula, R 8e represents H or an organic group (preferably an organic group not containing fluorine). R 10e is an alkylene group, and R 11e is an alkyl group which may have a substituent) is preferred. As R 6e a group represented by the general formula: -R 10e -CO-R 11e is more preferred.

[0338] As the organic group in R 8e an alkyl group is preferred. As R 8e H or a C 1-10 organic group is preferred, H or a C 1-4 organic group is more preferred, H or a C 1-4 alkyl group is even more preferred, and H is even more preferred.

[0339] R 10e The number of carbon atoms of the alkylene group of R 10e is preferably 1 or more, more preferably 3 or more, preferably 20 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. Also, the number of carbon atoms of the alkylene group of R

[0340] R 11eThe number of carbon atoms in the alkyl group may be 1 to 20, preferably 1 to 15, more preferably 1 to 12, still more preferably 1 to 10, even more preferably 1 to 8, particularly preferably 1 to 6, still more preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1. Further, the above R 11e The alkyl group preferably consists of only primary carbon, secondary carbon, and tertiary carbon, and particularly preferably consists of only primary carbon and secondary carbon. That is, R 11e Preferably, it is a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and particularly preferably a methyl group.

[0341] In formula (e), at least one of R 2e and R 5e is a group represented by the general formula: -X e -A e wherein the A e is -COOM e is also one of the preferred embodiments.

[0342] As the surfactant (e), a compound represented by the general formula (e-1), a compound represented by the general formula (e-2), or a compound represented by the general formula (e-3) is preferred, and a compound represented by the general formula (e-1) or a compound represented by the general formula (e-2) is more preferred.

[0343] General formula (e-1):

Chemical formula

[0344] General formula (e-2):

Chemical formula

[0345] General formula (e-3): [Chemical formula] (In the formula, R 2e , R 4e ~R 6e , X e , A e and Y e are as described above.)

[0346] General formula: -X e -A e As the group represented by, -COOM e , -R 12e COOM e , -SO3M e , -OSO3M e , -R 12e SO3M e , -R 12e OSO3M e , -OCO-R 12e -COOM e , -OCO-R 12e -SO3M e , -OCO-R 12e -OSO3M e , -COO-R 12e -COOM e , -COO-R 12e -SO3M e , -COO-R 12e -OSO3M e , -CONR 8e -R 12e -COOM e , -CONR 8e -R 12e -SO3M e , -CONR 8e -R 12e -OSO3M e , -NR 8e CO-R 12e -COOM e , -NR 8e CO-R 12e -SO3M e , -NR 8e CO-R 12e -OSO3M e , -OS(=O)2-R 12e -COOM e , -OS(=O)2-R 12e -SO3M e or -OS(=O)2-R 12e -OSO3M e (In the formula, R 8e and M e As stated above. R 12e is C 1-10 An alkylene group represented by the formula: is preferred. Above R 12e The alkylene group may have 75% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, 50% or less of the hydrogen atoms substituted with halogen atoms, or 25% or less of the hydrogen atoms substituted with halogen atoms, but is preferably a non-halogenated alkylene group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0347] General formula:-Y e -R 6e As the group represented by the formula: General formula:-R 10e -CO-R 11e A group represented by the formula: General formula:-OCO-R 10e -CO-R 11e A group represented by the formula: General formula:-COO-R 10e -CO-R 11e A group represented by the formula: General formula:-OCO-R 10e-COO-R 11e a group represented by General formula: -COO-R 11e a group represented by General formula: -NR 8e CO-R 10e -CO-R 11e a group represented by, or General formula: -CONR 8e -R 10e -NR 8e CO-R 11e a group represented by (wherein R 8e , R 10e and R 11e are as described above.) is preferred.

[0348] In the formula, R 4e and R 5e are each independently preferably H or an alkyl group of C 1-4 . The alkyl groups of the above R 4e and R 5e may have 75% or less of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, may have 50% or less substituted by halogen atoms, or may have 25% or less substituted by halogen atoms, but are preferably non-halogenated alkyl groups not containing halogen atoms such as fluorine atoms and chlorine atoms.

[0349] As R 3e in the general formula (e-1), H or an optionally substituted alkyl group of C 1-20 is preferred, an alkyl group of C 1-20 without substituents is more preferred, and H is even more preferred. The alkyl groups of the above R 3e may have 75% or less of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, may have 50% or less substituted by halogen atoms, or may have 25% or less substituted by halogen atoms, but are preferably non-halogenated alkyl groups not containing halogen atoms such as fluorine atoms and chlorine atoms.

[0350] R in the general formula (e-3) 2e is preferably H, OH, or an optionally substituted C 1-20 alkyl group, more preferably H, OH, or an unsubstituted C 1-20 alkyl group, and still more preferably H or OH. The above R 2e alkyl group may have 75% or less of the hydrogen atoms bonded to the carbon atoms substituted by halogen atoms, 50% or less substituted by halogen atoms, or 25% or less substituted by halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms and chlorine atoms.

[0351] The surfactant (e) can be produced by a known production method.

[0352] The above specific hydrocarbon surfactant is also preferably a carboxylic acid type hydrocarbon surfactant. The above carboxylic acid type hydrocarbon surfactant is not limited as long as it has a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is substituted by an inorganic cation (for example, a metal atom, ammonium, etc.). For example, among the above-mentioned specific hydrocarbon surfactants, a hydrocarbon surfactant having a carboxyl group or a group in which the hydrogen atom of the carboxyl group is substituted by an inorganic cation can be used. The above carboxylic acid type hydrocarbon surfactant preferably has a ratio of hydrogen atoms bonded to carbon atoms substituted by fluorine atoms of 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted by fluorine atoms at all).

[0353] As the above carboxylic acid type hydrocarbon surfactant, preferably, among at least one selected from the group consisting of the surfactant (c) represented by the above formula (c) and the surfactant (d) represented by the above formula (d), those having a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is substituted by an inorganic cation (for example, a metal atom, ammonium, etc.) are preferred.

[0354] It is also preferable that the specific hydrocarbon-based surfactant is a sulfonic acid type hydrocarbon-based surfactant. The sulfonic acid type hydrocarbon-based surfactant is not limited as long as it has a -SO3H group, -OSO3H group, or a group in which a hydrogen atom of these groups is substituted with an inorganic cation (for example, a metal atom, ammonium, etc.). For example, among the specific hydrocarbon-based surfactants described above, a hydrocarbon-based surfactant having a -SO3H group, -OSO3H group, or a group in which a hydrogen atom of these groups is substituted with an inorganic cation can be used. It is preferable that the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms in the sulfonic acid type hydrocarbon-based surfactant is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0355] The TFE-based polymer composition of the present disclosure can be efficiently produced by using at least one of the specific hydrocarbon-based surfactants. Further, the TFE-based polymer composition of the present disclosure may be produced by using two or more of the specific hydrocarbon-based surfactants at the same time, or a compound having other surfactant properties other than the specific hydrocarbon-based surfactant may be used at the same time as long as it has volatility or may remain in a molded body made of a TFE-based polymer or the like.

[0356] As the compound having other surfactant properties, for example, those described in JP-T-2013-542308, JP-T-2013-542309, JP-T-2013-542310, etc. can be used.

[0357] The compound having other surfactant properties may be a surfactant having a hydrophilic part and a hydrophobic part on the same molecule, for example, a hydrocarbon-based surfactant. These may be cationic, nonionic or anionic. It is preferable that the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms in the above compound is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0358] Cationic surfactants usually have a positively charged hydrophilic moiety such as alkylated ammonium bromide and other alkylated ammonium halides, and a hydrophobic moiety such as a long-chain fatty acid. It is preferable that the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms in the above cationic surfactant is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0359] Anionic surfactants usually have a hydrophilic moiety such as carboxylate, sulfonate or sulfate, and a hydrophobic moiety which is a long-chain hydrocarbon moiety such as alkyl. It is preferable that the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms in the above anionic surfactant is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0360] Nonionic surfactants usually do not contain a charged group and have a hydrophobic moiety which is a long-chain hydrocarbon. The hydrophilic moiety of nonionic surfactants contains water-soluble functional groups such as a chain of ethylene ether derived from polymerization with ethylene oxide. It is preferable that the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms in the above nonionic surfactant is 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted with fluorine atoms at all).

[0361] Examples of nonionic surfactants Polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerol esters, and their derivatives.

[0362] Specific examples of polyoxyethylene alkyl ethers: polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, etc.

[0363] Specific examples of polyoxyethylene alkyl phenyl ethers: polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, etc.

[0364] Specific examples of polyoxyethylene alkyl esters: polyethylene glycol monolaurate, polyethylene glycol monooleate, polyethylene glycol monostearate, etc.

[0365] Specific examples of sorbitan alkyl esters: polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, etc.

[0366] Specific examples of polyoxyethylene sorbitan alkyl esters: polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, etc.

[0367] Specific examples of glycerol esters: glycerol monomyristate, glycerol monostearate, glycerol monooleate, etc.

[0368] Specific examples of the above derivatives: polyoxyethylene alkyl amines, polyoxyethylene alkyl phenyl-formaldehyde condensates, polyoxyethylene alkyl ether phosphates, etc.

[0369] The above-mentioned ether and ester may have an HLB value of 10 to 18.

[0370] Examples of nonionic surfactants include Triton (registered trademark) X series (X15, X45, X100, etc.), Tergitol (registered trademark) 15-S series, Tergitol (registered trademark) TMN series (TMN-6, TMN-10, TMN-100, etc.), Tergitol (registered trademark) L series manufactured by Dow Chemical Company; Pluronic (registered trademark) R series (31R1, 17R2, 10R5, 25R4 (m~22, n~23)), Iconol (registered trademark) TDA series (TDA-6, TDA-9, TDA-10, etc.) manufactured by BASF.

[0371] Examples of anionic hydrocarbon surfactants include Versatic (registered trademark) 10 manufactured by Resolution Performance Products, Avanel S series (S-70, S-74, etc.) manufactured by BASF.

[0372] Other compounds having surfactant properties include R-L-M (wherein R is 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 having 3 or more carbon atoms, may contain a monovalent or divalent heterocyclic ring or may form a ring; L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - ; and M is H, a metal atom, NR 5 4 (R 5 may be the same or different and is H or an organic group (preferably an organic group not containing fluorine), an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent. -ArSO3 - is an aryl sulfonate.). Also included are anionic surfactants represented by the formula. R5 is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms. Specifically, those represented by CH3-(CH2) n -L-M (wherein n is an integer of 6 to 17. L and M are the same as above) can be mentioned. A mixture in which R is an alkyl group having 12 to 16 carbon atoms and L-M is a sulfate or sodium dodecyl sulfate (SDS) can also be used. As other compounds having surfactant properties, R 6 (-L-M)2 (wherein R 6 is a linear or branched alkylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylene group having 3 or more carbon atoms which may have a substituent. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocyclic ring or may form a ring. L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - and M is H, a metal atom, NR 5 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent or a phosphonium which may have a substituent, R 5 is H or an organic group (preferably an organic group not containing fluorine), -ArSO3 - is an arylsulfonate. ) Also included are anionic surfactants represented by As other compounds having surfactant properties, R 7 (-L-M)3 (wherein R 7 is a linear or branched alkylidine group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylidine group having 3 or more carbon atoms which may have a substituent. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocyclic ring or may form a ring. L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - and M is H, a metal atom, NR5 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 5 is H or an organic group (preferably an organic group not containing fluorine). -ArSO3 - is an arylsulfonate. ) Also included are anionic surfactants represented by

[0373] Examples of siloxane hydrocarbon surfactants include those described in Silicone Surfactants, R.M. Hill, Marcel Dekker, Inc., ISBN: 0-8247-00104. The structure of siloxane surfactants includes a distinct hydrophobic portion and a hydrophilic portion. The hydrophobic portion includes one or more dihydrocarbylsiloxane units, where the substituents on the silicone atoms are completely hydrocarbon. In the sense that when the carbon atoms of the hydrocarbyl group can be substituted by a halogen such as fluorine and are completely substituted by hydrogen atoms, these siloxane surfactants can also be regarded as hydrocarbon surfactants, that is, the monovalent substituents on the carbon atoms of the hydrocarbyl group are hydrogen. Preferably, the above siloxane surfactant has a ratio of hydrogen atoms bonded to carbon atoms substituted by fluorine atoms of 50% or less, more preferably 25% or less, still more preferably 10% or less, and most preferably 0% (not substituted by fluorine atoms at all).

[0374] Siloxane hydrocarbon surfactants are also disclosed in U.S. Patent No. 6,841,616.

[0375] Examples of siloxane-based anionic hydrocarbon surfactants include SilSense TM PE-100 silicone, SilSense TM CA-1 silicone, etc.

[0376] Examples of anionic hydrocarbon surfactants include sulfosuccinate surfactants such as Lankropol® K8300 manufactured by Akzo Nobel Surface Chemistry LLC. Examples of sulfosuccinate surfactants include diisodecyl Na sulfosuccinate (Emulsogen® SB10 manufactured by Clariant), diisotridecyl Na sulfosuccinate (Polirol® TR / LNA manufactured by Cesapinia Chemicals), and the like.

[0377] Examples of other compounds having surfactant properties include PolyFox® surfactants (PolyFox TM PF-156A, PolyFox TM PF-136A, etc.) manufactured by Omnova Solutions, Inc.

[0378] Other compounds having surfactant properties are preferably anionic hydrocarbon surfactants. As the anionic hydrocarbon surfactants, those described above can be adopted, and for example, the following hydrocarbon surfactants can be preferably adopted.

[0379] Examples of the above anionic hydrocarbon surfactants include, for example, the following formula (α): R 100 -COOM (α) (In the formula, R 100 is a monovalent organic group containing one or more carbon atoms (preferably an organic group not containing fluorine). M is H, a metal atom, NR 101 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, and R 101 is H or an organic group (preferably an organic group not containing fluorine), and they may be the same or different.) The compound (α) represented by the formula is included. As the organic group of R 101 , an alkyl group is preferred. R 101is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and still more preferably H or an alkyl group having 1 to 4 carbon atoms. From the viewpoint of surface activity, R 100 preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms. Also, from the viewpoint of water solubility, R 100 preferably has 29 or fewer carbon atoms, more preferably 23 or fewer carbon atoms. Examples of the metal atom of M include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred. M is preferably H, a metal atom, or NR 101 4, more preferably H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR 101 4, still more preferably H, Na, K, Li, or NH4, even more preferably Na, K, or NH4, particularly preferably Na or NH4, and most preferably NH4.

[0380] Examples of the compound (α) include anionic surfactants represented by R 102 -COOM (wherein R 102 is a linear or branched alkyl group, alkenyl group, alkylene group, or alkenylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group, alkenyl group, alkylene group, or alkenylene group having 3 or more carbon atoms which may have a substituent, and these may contain an ether bond. When the carbon number is 3 or more, it may contain a monovalent or divalent heterocyclic ring or may form a ring. M is the same as above). Specifically, those represented by CH3-(CH2) n -COOM (wherein n is an integer of 2 to 28. M is the same as above) are included.

[0381] The compound (α) may not contain a carbonyl group (excluding the carbonyl group in the carboxyl group) from the viewpoint of emulsion stability. Examples of the hydrocarbon-containing surfactant not containing the carbonyl group include, for example, the following formula (A1): R 103-COO-M (A1) (In the formula, R 103 is an alkyl group, alkenyl group, alkylene group or alkenylene group containing 6 to 17 carbon atoms, and these may contain an ether bond. M is H, a metal atom, NR 101 4, imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. R 101 is the same or different and is H or an organic group (preferably an organic group not containing fluorine).) Compounds are preferably exemplified. In the above formula (A1), R 103 is preferably an alkyl group or an alkenyl group (these may contain an ether group). The alkyl group or alkenyl group in the above R 103 may be linear or branched. The number of carbon atoms in the above R 103 is not limited, but is, for example, 2 to 29.

[0382] When the above alkyl group is linear, the number of carbon atoms in R 103 is preferably 3 to 29, and more preferably 5 to 23. When the above alkyl group is branched, the number of carbon atoms in R 103 is preferably 5 to 35, and more preferably 11 to 23. When the above alkenyl group is linear, the number of carbon atoms in R 103 is preferably 2 to 29, and more preferably 9 to 23. When the above alkenyl group is branched, the number of carbon atoms in R 103 is preferably 2 to 29, and more preferably 9 to 23.

[0383] Examples of the above alkyl group and alkenyl group include a methyl group, an ethyl group, an isobutyl group, a t-butyl group, a vinyl group and the like.

[0384] Examples of the above compound (α) include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, (9,12,15)-linolenic acid, (6,9,12)linolenic acid, eleostearic acid, arachidic acid, 8,11-eicosadienoic acid, mead acid, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, crotonic acid, myristoleic acid, palmitoleic acid, sapienic acid, elaidic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, α-eleostearic acid, β-eleostearic acid, dihomo-γ-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, bosseopentaenoic acid, eicosapentaenoic acid, osbond acid, sardine acid, tetracosapentaenoic acid, docosahexaenoic acid, nisinic acid, and salts thereof. In particular, at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecylic acid, palmitic acid, and salts thereof is preferable. Examples of the above salt include those in which the hydrogen of the carboxyl group is a metal atom of the above formula M, NR 11 4, an optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, and are not particularly limited.

[0385] Examples of the above anionic hydrocarbon surfactant also include, for example, the following formula (β): R 100 -SO3M (β) (In the formula, R 100 is a monovalent organic group containing one or more carbon atoms (preferably an organic group not containing fluorine). M is H, a metal atom, NR 101 4, an optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, and R 101is H or an organic group (preferably an organic group not containing fluorine), and they may be the same or different. The compound (β) represented by ) is also included. R 101 As the organic group, an alkyl group is preferable. R 101 is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and still more preferably H or an alkyl group having 1 to 4 carbon atoms. From the viewpoint of surfactant properties, R 100 preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms. Also, from the viewpoint of water solubility, R 100 preferably has 29 or fewer carbon atoms, more preferably 23 or fewer carbon atoms. Examples of the metal atom of M include alkali metals (Group 1), alkaline earth metals (Group 2), etc., and Na, K, or Li is preferable. As M, H, a metal atom, or NR 101 4 is preferable, H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR 101 4 is more preferable, H, Na, K, Li, or NH4 is still more preferable, Na, K, or NH4 is still more preferably, Na or NH4 is particularly preferable, and NH4 is most preferable.

[0386] Examples of the compound (β) include R 102 -SO3M (wherein R 102 is a linear or branched alkyl group, alkenyl group, alkylene group, or alkenylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group, alkenyl group, alkylene group, or alkenylene group having 3 or more carbon atoms which may have a substituent, and these may contain an ether bond. When the carbon number is 3 or more, it may contain a monovalent or divalent heterocyclic ring or may form a ring. M is the same as above.). An anionic surfactant represented by this formula is also included. Specifically, those represented by CH3-(CH2) n -SO3M (wherein n is an integer of 2 to 28. M is the same as above) are included.

[0387] From the perspective of emulsion stability, the above compound (β) may not contain a carbonyl group (excluding the carbonyl group in the carboxyl group). Examples of the hydrocarbon-containing surfactant that does not contain the above carbonyl group include, for example, the following formula (B1): R 103 -SO3-M (B1) (In the formula, R 103 is an alkyl group, alkenyl group, alkylene group or alkenylene group containing 6 to 17 carbon atoms, and these may contain an ether bond. M is H, a metal atom, NR 101 4, an imidazolium that may have a substituent, a pyridinium that may have a substituent, or a phosphonium that may have a substituent. R 101 is the same or different and is H or an organic group (preferably an organic group not containing fluorine).) Compounds are preferably exemplified. In the above formula (B), R 103 is preferably an alkyl group or an alkenyl group (these may contain an ether group). The alkyl group or alkenyl group in the above R 103 may be linear or branched. The number of carbon atoms in the above R 103 is not limited, but is, for example, 2 to 29.

[0388] When the above alkyl group is linear, the number of carbon atoms in R 103 is preferably 3 to 29, and more preferably 5 to 23. When the above alkyl group is branched, the number of carbon atoms in R 103 is preferably 5 to 35, and more preferably 11 to 23. When the above alkenyl group is linear, the number of carbon atoms in R 103 is preferably 2 to 29, and more preferably 9 to 23. When the above alkenyl group is branched, the number of carbon atoms in R 103 is preferably 2 to 29, and more preferably 9 to 23.

[0389] Examples of the above alkyl group and alkenyl group include a methyl group, an ethyl group, an isobutyl group, a t-butyl group, a vinyl group, and the like.

[0390] Examples of the above compound (β) include sulfonic acids such as aliphatic, unsaturated aliphatic, and aromatic sulfonic acids, sulfuric acid esters such as aliphatic, unsaturated aliphatic, and aromatic sulfuric acid esters, and salts thereof. Examples of the above sulfonic acid include 1-hexanesulfonic acid, 1-octanesulfonic acid, 1-decanesulfonic acid, 1-dodecanesulfonic acid, perfluorobutanesulfonic acid, linear alkylbenzenesulfonic acid, toluenesulfonic acid, cumenesulfonic acid, octylbenzenesulfonic acid, DBS, naphthalenesulfonic acid, naphthalenedisulfonic acid, naphthalenetrisulfonic acid, butylnaphthalenesulfonic acid. Examples of the above sulfuric acid ester include sodium alkyl sulfate, alpha-sulfo fatty acid ester salt, alkyl sulfate salt, polyoxyethylene alkyl ether sulfate salt, alpha-olefin sulfonate, lauryl sulfate, myristyl sulfate, laureth sulfate, polyoxyethylene alkylphenol sulfonic acid. As the above compound (β), at least one selected from the group consisting of saturated aliphatic and aromatic sulfuric acid esters and salts thereof is particularly preferable, and at least one selected from the group consisting of sodium alkyl sulfate, alpha-sulfo fatty acid ester salt, alkyl sulfate salt, polyoxyethylene alkyl ether sulfate salt, alpha-olefin sulfonate, lauryl sulfate, myristyl sulfate, laureth sulfate, polyoxyethylene alkylphenol sulfonic acid, and salts thereof is more preferable. Examples of the above salt include those in which the hydrogen of the sulfonic acid group is a metal atom of the above formula M, NR 11 4, an optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, and are not particularly limited.

[0391] Examples of the above anionic hydrocarbon surfactant include the following formula (1-0A): [Chemical formula] (In the formula, R 1A ~R 5A is H, a monovalent hydrocarbon group which may contain an ester group between carbon-carbon atoms, or a group represented by the general formula: -X A -A. However, at least one of R 2A and R 5A represents a group represented by the general formula: -X A -A.) X A is, in each occurrence, the same or different, a divalent hydrocarbon group, or a bond; A is, in each occurrence, the same or different, -COOM (M is H, a metal atom, NR 7 4, an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, and R 7 is H or an organic group (preferably an organic group not containing fluorine)); R 1A ~R 5A Among them, any two of them may be bonded to each other to form a ring.) Surfactants (1-0A), etc. represented by the formula are also included.

[0392] In the general formula (1-0A), for R 1A ~R 5A , the number of carbon atoms of the monovalent hydrocarbon group which may contain an ester group between carbon-carbon atoms is preferably 1 to 50, and more preferably 5 to 20. Any two of R 1A ~R 5A may be bonded to each other to form a ring. As the above monovalent hydrocarbon group which may contain an ester group between carbon-carbon atoms, an alkyl group is preferred. In the formula, for X A , the number of carbon atoms of the divalent hydrocarbon group is preferably 1 to 50, and more preferably 5 to 20. Examples of the above divalent hydrocarbon group include an alkylene group and an alkanediyl group, and an alkylene group is preferred.

[0393] In the general formula (1-0A), R2A and R 5A any one of them is preferably a group represented by the general formula: -X A -A, and R 2A is more preferably a group represented by the general formula: -X A -A.

[0394] In the general formula (1-0A), as a preferred embodiment, R 2A is a group represented by the general formula: -X A -A, and R 1A , R 3A , R 4A and R 5A are H. In this case, X A is preferably a bond or an alkylene group having 1 to 5 carbon atoms.

[0395] In the general formula (1-0A), as another preferred embodiment, R 2A is a group represented by the general formula: -X A -A, and R 1A and R 3A are groups represented by -Y A -R 6 , where Y A is the same or different in each occurrence and is -COO-, -OCO-, or a bond, and R 6 is the same or different in each occurrence and is an alkyl group having 2 or more carbon atoms. In this case, it is preferable that R 4A and R 5A are H.

[0396] Examples of the hydrocarbon surfactant represented by the general formula (1-0A) include glutaric acid or its salt, adipic acid or its salt, pimelic acid or its salt, suberic acid or its salt, azelaic acid or its salt, sebacic acid or its salt, and the like. In addition, the aliphatic carboxylic acid type hydrocarbon surfactant represented by the general formula (1-0A) may be a two-chain two-hydrophilic group type synthetic surfactant. For example, as gemini surfactants, Gemini SA-F (Chukyo Yushi Co., Ltd.), Gemsurf α142 (lauryl group with 12 carbon atoms), Gemsurf α102 (10 carbon atoms), Gemsurf α182 (14 carbon atoms), etc. can be mentioned.

[0397] As the above anionic hydrocarbon surfactant, the following formula I: R-(XZ) n (I) (In the formula, R is a hydrophobic hydrocarbon moiety containing one or more saturated or unsaturated, acyclic or cyclic aliphatic groups. The percentage of the total number of CH3 groups with respect to the total of CH3, CH2 and CH groups in one or more aliphatic groups is at least about 70%, and the hydrophobic moiety does not contain siloxane units. Each X may be the same or different and represents an ionic hydrophilic moiety. Each Z may be the same or different and represents one or more counterions of the ionic hydrophilic moiety. n is 1 to 3.) The compound I represented by this is also included.

[0398] Compound I shows low reactivity with polymerization initiators and / or growing fluoropolymer radicals in the emulsion polymerization of fluoromonomers.

[0399] Compound I has the following formula:

Chemical formula

[0400] Compound I has the following formula II:

Chemical formula

[0401] As the compound II, for example, the following compounds are preferred.

Chemical formula

[0402] Compound I is represented by the following formula III:

Chemical formula

[0403] As Compound III, for example, the following compounds are preferable.

Chemical formula

[0404] The TFE-based polymer composition of the present disclosure can be obtained by a production method including a polymerization step of polymerizing only tetrafluoroethylene or tetrafluoroethylene and a modified monomer copolymerizable with the tetrafluoroethylene in an aqueous medium having a pH of 4.0 or higher in the presence of a hydrocarbon-based surfactant and a polymerization initiator even when the above specific hydrocarbon-based surfactant is not used. Conventionally, since a polymerization initiator showing acidity has been used in the polymerization step for producing a TFE-based polymer, the pH of the aqueous medium used in the polymerization was less than 4.0. As a result of intensive studies by the present inventors, unexpectedly, it has been found that by setting the pH of the aqueous medium used in the polymerization to 4.0 or higher, the stability of the polymerization is improved and a TFE-based polymer having a high molecular weight can be produced. The above manufacturing method involves polymerizing only tetrafluoroethylene or tetrafluoroethylene and a modified monomer copolymerizable with the tetrafluoroethylene in an aqueous medium having a pH of 4.0 or higher. The pH may be 4.0 or higher, preferably more than 4.0, more preferably 4.5 or higher, still more preferably 5.0 or higher, even more preferably 5.5 or higher, particularly preferably 6.0 or higher, especially preferably 6.5 or higher, particularly preferably 7.0 or higher, particularly preferably 7.5 or higher, and particularly preferably 8.0 or higher. The upper limit of the pH is not particularly limited, and for example, it may be 13.0 or lower. From the perspective of corrosion of the polymerization tank, it is preferably 12.0 or lower, more preferably 11.5 or lower, and more preferably 11.0 or lower. The above pH can be measured using a pH meter.

[0405] In the above manufacturing method, the method for adjusting the pH of the aqueous medium to 4.0 or higher is not limited. For example, the pH can be adjusted to 4.0 or higher by using an alkaline aqueous solution, an aqueous dispersion showing alkalinity, or a pH adjuster, but it is not particularly limited. Also, even when using a polymerization initiator that shows acidity when dissolved in the aqueous medium, the pH can be adjusted to 4.0 or higher by further adding an alkali compound such as sodium hydroxide. The above alkali compound may be a compound that dissolves in water and ionizes to produce OH - Any compound that can generate it is acceptable. For example, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; hydroxides of alkaline earth metals; ammonia; amines, etc. can be mentioned, but it is not particularly limited. The above polymerization step may include a step of adding an alkali compound to the aqueous medium.

[0406] In the above manufacturing method, the pH of the aqueous medium may be 4.0 or higher throughout all periods of the polymerization step. Also, the pH may be 4.0 or higher in the middle stage of the polymerization step, or the pH may be 4.0 or higher in the latter half of the polymerization step. Further, the pH may be 4.0 or higher in both the middle and latter halves of the polymerization step.

[0407] In the above manufacturing method, the hydrocarbon-based surfactant is a hydrocarbon-based surfactant that does not contain fluorine, preferably an anionic hydrocarbon-based surfactant, and more preferably a carboxylic acid type hydrocarbon-based surfactant. The anionic hydrocarbon-based surfactant and the carboxylic acid type hydrocarbon-based surfactant are not particularly limited, but for example, the compound (α) exemplified among the above-described other compounds having surfactant properties can be preferably used.

[0408] In the above manufacturing method, the hydrocarbon-based surfactant is a hydrocarbon-based surfactant that does not contain fluorine, preferably an anionic hydrocarbon-based surfactant, and also preferably a sulfonic acid type hydrocarbon-based surfactant. The anionic hydrocarbon-based surfactant and the sulfonic acid type hydrocarbon-based surfactant are not particularly limited. For example, the compound (β) exemplified among the above-described other compounds having surfactant properties can be preferably used.

[0409] The TFE-based polymer composition of the present disclosure, even when the above specific hydrocarbon-based surfactant is not used, includes a polymerization step of polymerizing only tetrafluoroethylene or tetrafluoroethylene and a modified monomer copolymerizable with the tetrafluoroethylene in an aqueous medium in the presence of an anionic hydrocarbon-based surfactant and a polymerization initiator to obtain a TFE-based polymer, and the hydrocarbon-based surfactant includes a salt of the hydrocarbon-based surfactant. In other words, at least a part of the anionic hydrocarbon-based surfactant in the above polymerization step is in the form of a salt. As a result of intensive studies by the present inventors, unexpectedly, it has been found that the polymerization stability is improved by including a salt of the anionic hydrocarbon-based surfactant, and a TFE-based polymer having a large molecular weight can be produced. The above anionic hydrocarbon-based surfactant will be described later. The fact that the above anionic hydrocarbon-based surfactant contains a salt of the hydrocarbon-based surfactant can be confirmed by measuring the conductivity. In the above manufacturing method, it is preferable that the concentration of the salt of the anionic hydrocarbon surfactant is 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more with respect to the total mass of the anionic hydrocarbon surfactant. The ratio of the above salt can be measured by solution concentration and conductivity. In the above manufacturing method, it is more preferable that the hydrocarbon surfactant is a carboxylic acid type hydrocarbon surfactant. The hydrocarbon surfactant does not contain fluorine. In the salt of the anionic hydrocarbon surfactant, the cation (excluding hydrogen atom) that replaces the hydrogen atom of the acid is, for example, a metal atom, NR y 4 (R y may be the same or different, and is H or an organic group (preferably an organic group not containing fluorine), an imidazolium that may have a substituent, a pyridinium that may have a substituent, or a phosphonium that may have a substituent. The above R y is preferably H or an alkyl group, more preferably H or an alkyl group having 1 to 10 carbon atoms, and still more preferably H or an alkyl group having 1 to 4 carbon atoms. As the above cation in the salt of the anionic hydrocarbon surfactant, a metal atom or NR y 4 is preferable, NR y 4 is more preferable, and NH4 is still more preferable. Since the conductivity changes greatly with the influence of temperature, a constant temperature bath is used to keep the sample solution temperature at 25 °C, and the temperature of the cell of the pH meter is also made the same, and then the conductivity is measured.

[0410] In the above manufacturing method, it is preferable that the polymerization step is carried out substantially in the absence of the hydrocarbon surfactant in the form of an organic acid. By carrying out the polymerization substantially in the absence of the hydrocarbon surfactant in the form of an organic acid, the stability of the polymerization is further improved, and a high molecular weight TFE-based polymer can be obtained. The absence of the hydrocarbon surfactant in substantially the form of an organic acid preferably means that the concentration of the organic acid is 1.0% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, particularly preferably 0.05% by mass or less, and especially preferably 0.01% by mass or less based on the mass of the obtained aqueous dispersion. As used herein, "organic acid" means an organic compound exhibiting acidity. Examples of organic acids include carboxylic acids having a -COOH group, sulfonic acids having a -SO3H group, etc., and carboxylic acids are preferred from the viewpoint of ease of adjusting the pH of an aqueous solution containing the organic acid. Further, "the form of the organic acid" means a form in which H of the acidic group (e.g., -COOH group, -SO3H group, etc.) contained in the organic acid is not free. In the above production method, the hydrocarbon surfactant is an anionic hydrocarbon surfactant.

[0411] In the above polymerization step, the amount of the hydrocarbon surfactant at the start of polymerization is preferably more than 50 ppm with respect to the aqueous medium. The amount of the hydrocarbon surfactant at the start of polymerization is preferably 60 ppm or more, more preferably 70 ppm or more, still more preferably 80 ppm or more, and even more preferably 100 ppm or more. The upper limit is not particularly limited, but for example, it is preferably 10000 ppm and more preferably 5000 ppm. By the amount of the hydrocarbon surfactant at the start of polymerization being within the above range, an aqueous dispersion having a smaller average primary particle diameter and better stability can be obtained. It should be noted that the polymerization can be said to start when the gaseous TFE in the reactor becomes a TFE-based polymer and a pressure drop occurs in the reactor. U.S. Patent No. 3,391,099 (Punderson) discloses a dispersion polymerization of tetrafluoroethylene in an aqueous medium comprising two separate stages of a polymerization process: first, the formation of polymer nuclei as nucleation sites, and then a growth stage including the polymerization of the established particles. In addition, the polymerization usually starts when both the monomer to be polymerized and the polymerization initiator are charged into the reactor. In the present disclosure, an additive related to the formation of nucleation sites is used as a nucleating agent.

[0412] The above polymerization step preferably includes an addition step of adding a composition containing a hydrocarbon surfactant after the start of polymerization. By the above addition step, the stability of polymerization is further improved, and a higher molecular weight TFE-based polymer can be obtained. The above hydrocarbon surfactant may be in the form of a solid (for example, powder of a hydrocarbon surfactant) or in the form of a liquid. The above composition may be any composition containing a hydrocarbon surfactant, and may be composed only of a hydrocarbon surfactant, or may be a solution or dispersion of a hydrocarbon surfactant containing a hydrocarbon surfactant and a liquid medium. Therefore, the above addition step can also be referred to as a step of adding a hydrocarbon surfactant alone or a composition containing a hydrocarbon surfactant after the start of polymerization. The hydrocarbon surfactant is not limited to one type, and may be a mixture of two or more types. The above liquid medium may be either an aqueous medium or an organic solvent, or a combination of an aqueous medium and an organic solvent may be used. Specific examples of the above composition include an aqueous solution in which a hydrocarbon surfactant is dissolved in an aqueous medium, an aqueous dispersion in which a hydrocarbon surfactant is dispersed in an aqueous medium, and the like.

[0413] The hydrocarbon surfactant added in the above addition step is preferably 0.0001 to 10% by mass with respect to the aqueous medium. More preferably, it is 0.001% by mass or more, still more preferably 0.01% by mass or more, and particularly preferably 0.05% by mass or more with respect to the aqueous medium. Also, more preferably, it is 5% by mass or less, still more preferably 3% by mass or less, and particularly preferably 1% by mass or less with respect to the aqueous medium.

[0414] Since the stability of polymerization is improved and a higher molecular weight TFE-based polymer can be obtained, the above composition preferably is an aqueous solution containing a hydrocarbon surfactant and having a pH of 5.0 or more. The pH of the above aqueous solution is more preferably 6.0 or higher, still more preferably 6.5 or higher, even more preferably 7.0 or higher, particularly preferably 7.5 or higher, and especially preferably 8.0 or higher. Also, the upper limit of the pH is not particularly limited and may be 12.0 or lower, or may also be 11.0 or lower.

[0415] In the above addition step, the hydrocarbon surfactant is preferably an anionic hydrocarbon surfactant, and more preferably a carboxylic acid type hydrocarbon surfactant. The anionic hydrocarbon surfactant and the carboxylic acid type hydrocarbon surfactant are not particularly limited. For example, compounds such as compound (α) exemplified among the above-described compounds having other surfactant properties can be preferably used.

[0416] As the carboxylic acid type hydrocarbon surfactant used in the above polymerization step and addition step, the above surfactant (e), the anionic surfactant represented by the above formula: R 6 (-L-M)2, and among the anionic surfactants represented by the above formula: R 7 (-L-M)3, those having a group in which a carboxyl group (-COOH) or a hydrogen atom of the carboxyl group is substituted with an inorganic cation (for example, a metal atom, ammonium, etc.), the above compound (α), the above surfactant (1-0A), and at least one selected from the group consisting of those obtained by subjecting these surfactants to radical treatment or oxidation treatment is preferable. The above carboxylic acid type hydrocarbon surfactant may be used alone or as a mixture of two or more. In the above compound (α), the above formula: R 102 -COOM (wherein R 102And M is the same as above.) not only an anionic hydrocarbon surfactant represented by (preferably, a compound represented by the formula (A1)), but also an anionic surfactant represented by the above formula: R-L-M (wherein R, L and M are the same as above), among the above surfactant (c) and the above surfactant (d), those having a carboxyl group (-COOH) or a group in which a hydrogen atom of the carboxyl group is substituted with an inorganic cation (for example, a metal atom, ammonium, etc.) are also included.

[0417] The above carboxylic acid type hydrocarbon surfactant is preferably the above compound (α), the compound represented by the above formula (A1), in the above formula (c) A c is -COOX c in the compound, in the above formula (d) A d is -COOX d in the compound, in the above formula (e) A e is -COOM e in the compound, in the above formula (1-0A) the compound in which A is -COOM, and at least one selected from the group consisting of those obtained by subjecting these compounds to radical treatment or oxidation treatment is more preferable, and at least one selected from the group consisting of the compound represented by the above formula (A1) and those obtained by subjecting the compound to radical treatment or oxidation treatment is still more preferable. In particular, at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecanoic acid, palmitic acid, and their salts, and those obtained by subjecting these compounds to radical treatment or oxidation treatment is preferable. Examples of the above salts include those in which the hydrogen of the carboxyl group is the metal atom of the above formula M, NR 101 4, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, but are not particularly limited.

[0418] The above production method preferably polymerizes tetrafluoroethylene substantially in the absence of a fluorine-containing surfactant. In the above manufacturing method, "in the substantial absence of a fluorine-containing surfactant" means that the fluorine-containing surfactant is 10 mass ppm or less, preferably 1 mass ppm or less, more preferably 100 mass ppb or less, still more preferably 10 mass ppb or less, even more preferably less than 10 mass ppb, even more preferably 1 mass ppb or less, and particularly preferably less than 1 mass ppb, with respect to the aqueous medium. "In the substantial absence of a fluorine-containing surfactant" also means that there is no intentional addition of a fluorine-containing surfactant.

[0419] Examples of the above fluorine-containing surfactant include anionic fluorine-containing surfactants. The above anionic fluorine-containing surfactant may be, for example, a surfactant containing fluorine atoms and having a total carbon number of 20 or less in the portion excluding the anionic group.

[0420] The above fluorine-containing surfactant may also be a surfactant containing fluorine and having a molecular weight of the anionic portion of 1000 or less, preferably 800 or less. Note that the above "anionic portion" means the portion excluding the cation of the above fluorine-containing surfactant. For example, in the case of F(CF2) n1 COOM represented by the formula (I) described later, it is the portion of "F(CF2) n1 COO".

[0421] Specific examples of the fluorosurfactant include those described in 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 No. 3250808, U.S. Patent No. 3271341, Japanese Patent Application 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, U.S. Patent Application Publication No. 2014 / 0228531, International Publication No. 2013 / 189824, International Publication No. 2013 / 189826, etc.

[0422] Examples of the anionic fluorosurfactant include the compounds represented by the above general formula (N 0 ).

[0423] As described above, examples of the anionic fluorosurfactant include carboxylic acid-based fluorosurfactants, sulfonic acid-based fluorosurfactants, and the like.

[0424] The TFE-based polymer composition of the present disclosure can be preferably produced by a production method including an addition step of adding at least one selected from the group consisting of a radical scavenger and a decomposition agent of a polymerization initiator. The above addition step is performed during the step of performing the above emulsion polymerization in an aqueous medium. By adding a radical scavenger or a decomposition agent of a polymerization initiator, the radical concentration during polymerization can be adjusted. From the viewpoint of reducing the radical concentration, a radical scavenger is preferred.

[0425] As the radical scavenger, a compound that does not have restart ability after addition to or chain transfer with free radicals in the polymerization system is used. Specifically, a compound that easily undergoes a chain transfer reaction with primary radicals or growing radicals and then generates stable radicals that do not react with monomers, or a compound that has a function of easily undergoing an addition reaction with primary radicals or growing radicals to generate stable radicals is used. What is generally called a chain transfer agent is characterized by its activity in terms of the chain transfer constant and the restart efficiency. Among chain transfer agents, those with a restart efficiency of almost 0% are called radical scavengers. The above radical scavenger can also be, for example, a compound in which the chain transfer constant with TFE at the polymerization temperature is larger than the polymerization rate constant and the restart efficiency is substantially 0%. "The restart efficiency is substantially 0%" means that the generated radicals are converted into stable radicals by the radical scavenger. Preferably, it is a compound in which the chain transfer constant (Cs) with TFE at the polymerization temperature (= chain transfer rate constant (kc) / polymerization rate constant (kp)) is greater than 0.1. For the above compound, it is more preferable that the chain transfer constant (Cs) is 0.5 or more, still more preferable that it is 1.0 or more, even more preferable that it is 5.0 or more, and particularly preferable that it is 10 or more.

[0426] As the radical scavenger in the present disclosure, for example, at least one selected from the group consisting of aromatic hydroxy compounds, aromatic amines, N,N - diethylhydroxylamine, quinone compounds, terpenes, thiocyanates, and cupric chloride (CuCl2) is preferable. Examples of aromatic hydroxy compounds include unsubstituted phenol, polyhydric phenols, salicylic acid, m - or p - salicylic acid, gallic acid, naphthol, and the like. Examples of the above unsubstituted phenol include о -, m - or p - nitrophenol, о -, m - or p - aminophenol, p - nitrosophenol, and the like. Examples of polyhydric phenols include catechol, resorcinol, hydroquinone, pyrogallol, phloroglucinol, naphthoresorcinol, and the like. Examples of the aromatic amines include o-, m- or p-phenylenediamine, benzidine and the like. Examples of the quinone compounds include o-, m- or p-benzoquinone, 1,4-naphthoquinone, alizarin and the like. Examples of the thiocyanates include ammonium thiocyanate (NH4SCN), potassium thiocyanate (KSCN), sodium thiocyanate (NaSCN) and the like. Among the above radical scavengers, aromatic hydroxy compounds are preferred, unsubstituted phenols or polyhydric phenols are more preferred, and hydroquinone is even more preferred.

[0427] From the viewpoint of reducing the standard specific gravity, the addition amount of the above radical scavenger is preferably an amount corresponding to 3 to 500% (molar basis) of the concentration of the polymerization initiator. The more preferable lower limit is 5% (molar basis), even more preferably 8% (molar basis), even more preferably 10% (molar basis), even more preferably 15% (molar basis), particularly preferably 20% (molar basis), particularly preferably 25% (molar basis), particularly preferably 30% (molar basis), particularly preferably 35% (molar basis). The more preferable upper limit is 400% (molar basis), even more preferably 300% (molar basis), even more preferably 200% (molar basis), particularly preferably 100% (molar basis).

[0428] The decomposer of the polymerization initiator may be any compound that can decompose the polymerization initiator used. For example, at least one selected from the group consisting of sulfites, bisulfites, bromates, diimines, diimine salts, oxalic acid, oxalates, copper salts, and iron salts is preferred. Examples of the sulfites include sodium sulfite and ammonium sulfite. Examples of the copper salts include copper(II) sulfate, and examples of the iron salts include iron(II) sulfate. The addition amount of the decomposer of the above polymerization initiator is added in the range of 25 to 300% by mass based on the amount of the oxidizing agent combined as the polymerization initiator (redox initiator described later). Preferably it is 25 to 150% by mass, more preferably 50 to 100% by mass. From the viewpoint of reducing the standard specific gravity, the addition amount of the decomposer of the polymerization initiator is preferably an amount corresponding to 3 to 500% (molar basis) of the polymerization initiator concentration. A more preferable lower limit is 5% (molar basis), still more preferably 8% (molar basis), still more preferably 10% (molar basis), still more preferably 13% (molar basis), and even more preferably 15% (molar basis). A more preferable upper limit is 400% (molar basis), still more preferably 300% (molar basis), even more preferably 200% (molar basis), and particularly preferably 100% (molar basis).

[0429] At least one selected from the group consisting of a radical scavenger and a decomposer of a polymerization initiator is preferably added when the concentration of the TFE-based polymer formed in the aqueous medium is 5% by mass or more. More preferably, it is when it is 10% by mass or more. Also, it is preferably added when the concentration of the TFE-based polymer formed in the aqueous medium is 40% by mass or less. More preferably, it is when it is 35% by mass or less, and still more preferably, it is when it is 30% by mass or less.

[0430] The addition step may be a step of continuously adding at least one selected from the group consisting of a radical scavenger and a decomposer of a polymerization initiator. Continuously adding at least one selected from the group consisting of a radical scavenger and a decomposer of a polymerization initiator means, for example, adding at least one selected from the group consisting of a radical scavenger and a decomposer of a polymerization initiator not all at once, but over time, continuously or in portions.

[0431] The polymerization step may be one in which tetrafluoroethylene is polymerized in the presence of a nucleating agent.

[0432] As the nucleating agent, for example, it is preferably at least one selected from the group consisting of fluoropolyethers, nonionic surfactants, and chain transfer agents. In this case, the polymerization step is preferably a step of obtaining a TFE-based polymer by polymerizing tetrafluoroethylene in an aqueous medium in the presence of a hydrocarbon-based surfactant and the nucleating agent.

[0433] As the fluoropolyether, perfluoropolyether is preferable.

[0434] The fluoropolyether preferably has repeating units represented by formulas (1a) to (1d). (-CFCF3-CF2-O-) n (1a) (-CF2-CF2-CF2-O-) n (1b) (-CF2-CF2-O-) n -(-CF2-O-) m (1c) (-CF2-CFCF3-O-) n -(-CF2-O-) m (1d) (In formulas (1a) to (1d), m and n are integers of 1 or more.)

[0435] As the fluoropolyether, a fluoropolyether acid or a salt thereof is preferable. The fluoropolyether acid is preferably a carboxylic acid, a sulfonic acid, a sulfonamide, or a phosphonic acid, and more preferably a carboxylic acid. Among the fluoropolyether acid or a salt thereof, a salt of the fluoropolyether acid is preferable, an ammonium salt of the fluoropolyether acid is more preferable, and an ammonium salt of the fluoropolyether carboxylic acid is still more preferable.

[0436] The fluoropolyether acid or a salt thereof can have any chain structure in which oxygen atoms in the main chain of the molecule are separated by saturated fluorocarbon groups having 1 to 3 carbon atoms. Two or more types of fluorocarbon groups can be present in the molecule.

[0437] As the fluoropolyether acid or a salt thereof, the following formula: CF3-CF2-CF2-O(-CFCF3-CF2-O-) n CFCF3-COOH, CF3-CF2-CF2-O(-CF2-CF2-CF2-O-) n -CF2-CF2COOH, or, HOOC-CF2-O(-CF2-CF2-O-) n -(-CF2-O-) m CF2COOH (wherein m and n are the same as defined above.) It is preferably a compound represented by the formula or a salt thereof.

[0438] These structures have been studied by Kasai in J. Appl. Polymer Sci., 57, 797 (1995). As disclosed herein, such fluoropolyethers can have a carboxylic acid group or a salt thereof at one or both ends. Similarly, such fluoropolyethers can have a sulfonic acid or phosphonic acid group or a salt thereof at one or both ends. In addition, fluoropolyethers having acid functional groups at both ends can have different groups at each end. For monofunctional fluoropolyethers, the other end of the molecule is usually perfluorinated, but may contain hydrogen or chlorine atoms.

[0439] Fluoropolyethers having an acid group at one or both ends have 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 fluorocarbon groups separating the ether oxygens, more preferably at least 2 of such fluorocarbon groups, have 2 or 3 carbon atoms. Even more preferably, at least 50% of the fluorocarbon groups separating the ether oxygens have 2 or 3 carbon atoms. Also preferably, the fluoropolyether has a total of at least 15 carbon atoms. For example, the preferred minimum value of n or n + m in the above repeating unit structure is at least 5. Two or more fluoropolyethers having an acid group at one or both ends can be used in the method according to the present disclosure. Typically, unless special care is taken in the production of a single specific fluoropolyether compound, the fluoropolyether can contain a plurality of compounds in various proportions within the molecular weight range relative to the number average molecular weight.

[0440] The above fluoropolyether preferably has a number average molecular weight of 800 g / mol or more. Since the fluoropolyether acid or its salt may be difficult to disperse in an aqueous medium, it preferably has a number average molecular weight of less than 6000 g / mol. The fluoropolyether acid or its salt more preferably has a number average molecular weight of 800 to 3500 g / mol, and even more preferably 1000 to 2500 g / mol.

[0441] The amount of the above fluoropolyether is preferably 5 to 3000 ppm with respect to the aqueous medium, more preferably 5 to 2000 ppm, and the even more preferred lower limit is 10 ppm, and the even more preferred upper limit is 100 ppm.

[0442] Examples of the nonionic surfactant as the above nucleating agent include the nonionic surfactants described above, and it is preferably a nonionic surfactant that does not contain fluorine. For example, as the above nonionic surfactant, the following general formula (i) R3 -O-A 1 -H (i) (In the formula, R 3 is a linear or branched primary or secondary alkyl group having 8 to 18 carbon atoms, and A 1 is a polyoxyalkylene chain.) Examples of the compound represented thereby include. R 3 Preferably has 10 to 16 carbon atoms, more preferably 12 to 16 carbon atoms. When the number of carbon atoms of R 3 is 18 or less, good dispersion stability of the aqueous dispersion is easily obtained. When the number of carbon atoms of R 3 exceeds 18, the flow temperature is high and it is difficult to handle. When the number of carbon atoms of R 3 is less than 8, the surface tension of the aqueous dispersion becomes high, and the permeability and wettability tend to decrease.

[0443] The polyoxyalkylene chain may be composed of oxyethylene and oxypropylene. It is a polyoxyalkylene chain consisting of an average repeat number of 5 to 20 of oxyethylene groups and an average repeat number of 0 to 2 of oxypropylene groups, and is a hydrophilic group. The number of oxyethylene units can include either a broad or narrow unimodal distribution that is normally provided, or a broader or bimodal distribution obtained by blending. When the average repeat number of oxypropylene groups exceeds 0, the oxyethylene groups and oxypropylene groups in the polyoxyalkylene chain may be arranged in a block form or in a random form. From the viewpoints of the viscosity and stability of the aqueous dispersion, a polyoxyalkylene chain composed of an average repeat number of 7 to 12 of oxyethylene groups and an average repeat number of 0 to 2 of oxypropylene groups is preferred. In particular, when A 1 has an average of 0.5 to 1.5 oxypropylene groups, it has good low foaming properties and is preferred.

[0444] More preferably, R 3is (R’)(R’’)HC-, where 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.

[0445] Specific examples of the above polyoxyethylene alkyl ether include C 13 H 27 -O-(C2H4O) 10 -H, C 12 H 25 -O-(C2H4O) 10 -H, C 10 H 21 CH(CH3)CH2-O-(C2H4O)9-H, C 13 H 27 -O-(C2H4O)9-(CH(CH3)CH2O)-H, C 16 H 33 -O-(C2H4O) 10 -H, HC(C5H 11 )(C7H 15 )-O-(C2H4O)9-H, etc. Examples of commercially available products of the above polyoxyethylene alkyl ether include, for example, Genapol X080 (product name, manufactured by Clariant), Neugen TDS-80 (trade name), the Neugen TDS series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) with Neugen TDS-80 as an example, the Leocol TD series (manufactured by Lion Corporation) with Leocol TD-90 (trade name) as an example, the Lionol (registered trademark) TD series (manufactured by Lion Corporation), the T-Det A series (manufactured by Harcros Chemicals) with T-Det A138 (trade name) as an example, the Tergitol (registered trademark) 15S series (manufactured by Dow), etc.

[0446] The nonionic surfactant is preferably an ethoxylate of 2,6,8-trimethyl-4-nonanol having an average of about 4 to about 18 ethylene oxide units, an ethoxylate of 2,6,8-trimethyl-4-nonanol having an average of about 6 to about 12 ethylene oxide units, or a mixture thereof. This type of nonionic surfactant is also commercially available, for example, as TERGITOL TMN-6, TERGITOL TMN-10, and TERGITOL TMN-100X (all product names, manufactured by Dow Chemical Company).

[0447] Also, the hydrophobic group of the nonionic surfactant may be any of an alkylphenol group, a linear alkyl group, and a branched alkyl group. For example, as the polyoxyethylene alkylphenyl ether-based nonionic compound, for example, the following general formula (ii) R 4 -C6H4-O-A 2 -H (ii) (In the formula, R 4 is a linear or branched primary or secondary alkyl group having 4 to 12 carbon atoms, and A 2 is a polyoxyalkylene chain.) Compounds represented by this formula are exemplified. Specific examples of the polyoxyethylene alkylphenyl ether-based nonionic compound include Triton (registered trademark) X-100 (product name, manufactured by Dow Chemical Company) and the like.

[0448] As other nonionic surfactants, a bifunctional block copolymer supplied as the Pluronic (registered trademark) R series from BASF, a tridecyl alcohol alkoxylate supplied as the Iconol (registered trademark) TDA series from BASF Corporation, a hydrocarbon-containing siloxane surfactant, preferably a hydrocarbon surfactant, where when the above hydrocarbyl group can be substituted by a halogen such as fluorine, it is completely substituted by a hydrogen atom, whereby these siloxane surfactants can also be regarded as hydrocarbon surfactants, that is, the monovalent substituent on the hydrocarbyl group is hydrogen.

[0449] Also, in the above manufacturing method, in addition to the above specific hydrocarbon surfactant and other compounds having surfactant properties used as desired, additives can be used to stabilize each compound. Examples of the above additives include buffers, pH adjusters, stabilization aids, dispersion stabilizers, and the like.

[0450] As the stabilization aid, paraffin wax, fluorinated oil, fluorinated solvent, silicone oil, etc. are preferable. The stabilization aid may be used alone or in combination of two or more. As the stabilization aid, paraffin wax is more preferable. The paraffin wax may be liquid, semi-solid, or solid at room temperature, but saturated hydrocarbons having 12 or more carbon atoms are preferable. The melting point of the paraffin wax is usually preferably 40 to 65°C, more preferably 50 to 65°C.

[0451] The amount of the stabilization 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 stabilization aid is sufficiently hydrophobic and is desirably completely separated from the TFE-based polymer aqueous emulsion after the emulsion polymerization of TFE and does not become a contaminating component.

[0452] In the above manufacturing method, the emulsion polymerization can be carried out by charging an aqueous medium, the above hydrocarbon surfactant, a monomer, and other additives as necessary into a polymerization reactor, stirring the contents of the reactor, and 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 start of the polymerization reaction, monomers, polymerization initiators, chain transfer agents, and the above surfactants, etc. may be additionally added according to the purpose. The above hydrocarbon surfactant may be added after the polymerization reaction has started.

[0453] In the above emulsion polymerization, the polymerization temperature and polymerization pressure are appropriately determined according to the type of monomer used, the molecular weight of the target TFE-based polymer, and the reaction rate. Usually, the polymerization temperature is 5 to 150 °C, preferably 10 °C or higher, more preferably 30 °C or higher, and still more preferably 50 °C or higher. Also, it is more preferably 120 °C or lower, and still more preferably 100 °C or lower. The polymerization pressure is 0.05 to 10 MPaG. The polymerization pressure is more preferably 0.3 MPaG or higher, and still more preferably 0.5 MPaG or higher. Also, it is more preferably 5.0 MPaG or lower, and still more preferably 3.0 MPaG or lower. In particular, from the viewpoint of improving the yield, it is preferably 1.0 MPaG or higher, more preferably 1.2 MPaG or higher, still more preferably 1.5 MPaG or higher, still more preferably 1.8 MPaG or higher, and particularly preferably 2.0 MPaG or higher.

[0454] In the above emulsion polymerization, the hydrocarbon-based surfactant is preferably added when the concentration of the TFE-based polymer formed in the aqueous medium is less than 0.60% by mass. More preferably, the above concentration is 0.50% by mass or less, still more preferably 0.36% by mass or less, still more preferably 0.30% by mass or less, particularly preferably 0.20% by mass or less, and most preferably added at the start of polymerization. The above concentration is the concentration relative to the total of the aqueous medium and the TFE-based polymer. Also, in the above emulsion polymerization, the amount of the hydrocarbon-based surfactant at the start of polymerization is preferably 1 ppm or more based on the aqueous medium. The amount of the hydrocarbon-based surfactant at the start of polymerization is preferably 10 ppm or more, more preferably 50 ppm or more, still more preferably 100 ppm or more, and still more preferably 200 ppm or more. The upper limit is not particularly limited, but for example, it is preferably 100000 ppm, and more preferably 50000 ppm. By the amount of the hydrocarbon-based surfactant at the start of polymerization being in the above range, an aqueous dispersion with a smaller average primary particle diameter and better stability can be obtained.

[0455] As the polymerization initiator, any compound that can generate radicals within the above polymerization temperature range is not particularly limited, and known oil-soluble and / or water-soluble polymerization initiators can be used. Further, polymerization can also be initiated as a redox system in combination with a reducing agent or the like. The concentration of the polymerization initiator is appropriately determined according to the type of monomer, the molecular weight of the target TFE-based polymer, and the reaction rate.

[0456] As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

[0457] The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, and typical examples include dialkyl peroxydicarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate, peroxy esters such as t-butyl peroxyisobutyrate and t-butyl peroxypivalate, and dialkyl peroxides such as di-t-butyl peroxide.

[0458] The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples include ammonium salts, potassium salts, sodium salts, such as persulfuric acid, perboric acid, perchloric acid, phosphoric acid, and percarbonic acid, t-butyl permaleate, t-butyl hydroperoxide, and the like. Reducing agents such as sulfites and sulfites may also be included, and the amount used may be 0.1 to 20 times that of the peroxide.

[0459] For example, when polymerization is carried out at a low temperature of 30°C or lower, it is preferable to use a redox initiator that combines an oxidizing agent and a reducing agent as the polymerization initiator. Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, ammonium cerium nitrate, bromates, and the like. Examples of the reducing agent include sulfites, bisulfites, bromates, diimines, oxalic acid, and the like. Examples of the persulfate include ammonium persulfate and potassium persulfate. Examples of the sulfite include sodium sulfite and ammonium sulfite. In order to increase the decomposition rate of the initiator, it is also preferable to add a copper salt or an iron salt to the combination of the redox initiator. Examples of the copper salt include copper(II) sulfate, and examples of the iron salt include iron(II) sulfate.

[0460] As the above redox initiator, it is preferable that the oxidizing agent is permanganic acid or its salt, persulfate, manganese triacetate, cerium(IV) salt, or bromic acid or its salt, and the reducing agent is dicarboxylic acid or its salt, or diimine. More preferably, the oxidizing agent is permanganic acid or its salt, persulfate, or bromic acid or its salt, and the reducing agent is dicarboxylic acid or its salt.

[0461] Examples of the above redox initiator include combinations such as potassium permanganate / oxalic acid, potassium permanganate / ammonium oxalate, manganese triacetate / oxalic acid, manganese triacetate / ammonium oxalate, ammonium cerium nitrate / oxalic acid, ammonium cerium nitrate / ammonium oxalate, and the like. When using a redox initiator, either the oxidizing agent or the reducing agent may be charged into the polymerization tank in advance, and then the other may be added continuously or intermittently to initiate polymerization. For example, when using potassium permanganate / ammonium oxalate, it is preferable to charge ammonium oxalate into the polymerization tank and continuously add potassium permanganate thereto. In addition, in the redox initiator of this specification, when "potassium permanganate / ammonium oxalate" is described, it means a combination of potassium permanganate and ammonium oxalate. The same applies to other compounds. As the above redox initiator, it is preferable to use an oxidizing agent or a reducing agent capable of making the pH of the aqueous solution of the redox initiator 4.0 or higher. The above aqueous solution of the redox initiator means an aqueous solution with a concentration of 0.50% by mass of the oxidizing agent or an aqueous solution with a concentration of 0.50% by mass of the reducing agent. That is, it is sufficient that the pH of at least one of the aqueous solution with a concentration of 0.50% by mass of the oxidizing agent and the aqueous solution with a concentration of 0.50% by mass of the reducing agent is 4.0 or higher, and it is preferable that the pH of both the aqueous solution with a concentration of 0.50% by mass of the oxidizing agent and the aqueous solution with a concentration of 0.50% by mass of the reducing agent is 4.0 or higher. The pH of the above aqueous solution of the redox initiator (aqueous solution with a concentration of 0.50% by mass of the oxidizing agent or aqueous solution with a concentration of 0.50% by mass of the reducing agent) is more preferably 5.0 or higher, further preferably 5.5 or higher, and particularly preferably 6.0 or higher, respectively.

[0462] The above redox initiator is particularly preferably a combination of an oxidizing agent that is a salt and a reducing agent that is a salt. For example, the oxidizing agent that is a salt is more preferably at least one selected from the group consisting of persulfates, permanganates, cerium(IV) salts, and bromates, further preferably a permanganate, and particularly preferably potassium permanganate. In addition, the reducing agent that is a salt is more preferably at least one selected from the group consisting of oxalates, malonates, succinates, glutarates, and bromates, further preferably an oxalate, and particularly preferably ammonium oxalate.

[0463] Specific examples of the redox initiator preferably include at least one selected from the group consisting of potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, manganese triacetate / ammonium oxalate, and ammonium cerium nitrate / ammonium oxalate, and more preferably at least one selected from the group consisting of potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, and ammonium cerium nitrate / ammonium oxalate.

[0464] By using a redox initiator in the polymerization step, the molecular weight of the resulting TFE-based polymer can be increased. Therefore, the SSG can be decreased, and the polymer can be made stretchable. Also, by using a redox initiator in the polymerization step, the number of particles of the TFE-based polymer formed in the aqueous dispersion can be increased. Also, the yield of the TFE-based polymer can be increased. When using a redox initiator, the oxidizing agent and the reducing agent may be added all at once at the beginning of polymerization, or the reducing agent may be added all at once at the beginning of polymerization and the oxidizing agent may be added continuously, or the oxidizing agent may be added all at once at the beginning of polymerization and the reducing agent may be added continuously, or both the oxidizing agent and the reducing agent may be added continuously. When using a redox initiator as the polymerization initiator, the addition amount of the oxidizing agent is preferably 5 to 10000 ppm, more preferably 10 to 1000 ppm, and the addition amount of the reducing agent is preferably 5 to 10000 ppm, more preferably 10 to 1000 ppm, based on the aqueous medium. Also, when using a redox initiator in the polymerization step, the polymerization temperature is preferably 100°C or lower, more preferably 95°C or lower, and still more preferably 90°C or lower. Also, it is preferably 10°C or higher, more preferably 20°C or higher, and still more preferably 30°C or higher.

[0465] The addition amount of the polymerization initiator is not particularly limited, but it may be added all at once, sequentially, or continuously at the initial stage of polymerization in an amount such that the polymerization rate does not significantly decrease (for example, several ppm with respect to the water concentration). The upper limit is in a range where the reaction temperature may be increased while removing the heat of polymerization reaction from the equipment surface. A more preferable upper limit is in a range where the heat of polymerization reaction can be removed from the equipment surface. More specifically, for example, 1 ppm or more is preferable with respect to the aqueous medium, 10 ppm or more is more preferable, and 50 ppm or more is even more preferable. Also, 100000 ppm or less is preferable, 10000 ppm or less is more preferable, and 5000 ppm or less is even more preferable.

[0466] The above aqueous medium is a reaction medium for carrying out polymerization and means a liquid containing water. The above aqueous medium is not particularly limited as long as it contains water, and may contain water and, for example, a fluorine-free organic solvent such as alcohol, ether, ketone, etc., and / or a fluorine-containing organic solvent having a boiling point of 40 °C or lower.

[0467] In the above emulsion polymerization, further, according to the purpose, a known chain transfer agent can be added to adjust the polymerization rate and molecular weight.

[0468] Examples of the above chain transfer agent include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, dimethyl succinate, etc., and various halogenated hydrocarbons such as isopentane, methane, ethane, propane, isobutane, methanol, ethanol, isopropanol, acetone, various mercaptans, carbon tetrachloride, and cyclohexane.

[0469] A bromine compound or an iodine compound may be used as the chain transfer agent. Examples of the polymerization method using a bromine compound or an iodine compound include, for example, a method of polymerizing a fluoromonomer 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, for example, the general formula: R a Ix Br y (wherein x and y are each an integer from 0 to 2 and satisfy 1 ≤ x + y ≤ 2, and R a is a saturated or unsaturated fluorohydrocarbon group or chlorofluorohydrocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms, which may contain an oxygen atom). Examples of the compound include those represented by the formula. By using a bromine compound or an iodine compound, iodine or bromine is introduced into the polymer and functions as a crosslinking point.

[0470] 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-diiodoperfluorhexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodo-n-propane, CF2Br2, BrCF2CF2Br, CF3CFBrCF2Br, CFClBr2, BrCF2CFClBr, CFBrClCFClBr, BrCF2CF2CF2Br, BrCF2CFBrOCF3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobuten-1, 2-bromo-4-iodoperfluorobuten-1, monoiodomonobromo substitution products of benzene, diiodomonobromo substitution products, and (2-iodoethyl) and (2-bromoethyl) substitution products. These compounds may be used alone or in combination with each other.

[0471] Among these, from the viewpoints of polymerization reactivity, crosslinking reactivity, availability, etc., it is preferable to use 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, or 2-iodoperfluoropropane.

[0472] The amount of the chain transfer agent used is usually 1 to 50,000 ppm, preferably 1 to 20,000 ppm, based on the total amount of the fluoromonomer supplied.

[0473] The above chain transfer agent may be added all at once into the reaction vessel before the start of polymerization, or may be added all at once after the start of polymerization, or may be added in multiple portions during polymerization, or may be added continuously during polymerization.

[0474] An aqueous dispersion of the TFE-based polymer can be obtained by step (A2). The above aqueous dispersion usually contains a TFE-based polymer, compound (1) and / or (2), and an aqueous medium. The solid content concentration of the above aqueous dispersion is not limited, but may be, for example, 1.0 to 70% by mass. The solid content concentration is preferably 8.0% by mass or more, more preferably 10.0% by mass or more, and preferably 60.0% by mass or less, more preferably 50.0% by mass or less. In the above production method, the adhesion amount is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.8% by mass or less, still more preferably 0.7% by mass or less, and particularly preferably 0.6% by mass or less, based on the finally obtained TFE-based polymer.

[0475] The coagulation in step (B) can be carried out by a known method. When coagulation is carried out on the above aqueous dispersion of the TFE-based polymer, usually, an aqueous dispersion obtained by polymerization such as a polymer latex is diluted with water to a polymer concentration of 10 to 25% by mass (preferably a polymer concentration of 10 to 20% by mass), and in some cases, after adjusting the pH to neutral or alkaline, it is carried out by stirring more vigorously than the stirring during the reaction in a container equipped with a stirrer. The above coagulation may be carried out while adding a water-soluble organic compound such as methanol or acetone, an inorganic salt such as potassium nitrate or ammonium carbonate, or an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid as a coagulant. The above coagulation may also be carried out continuously using an in-line mixer or the like.

[0476] The drying (heat treatment) in step (C) is usually carried out using means such as vacuum, high frequency, hot air, etc. while keeping the above-mentioned wet powder in a state where it is not overly fluidized, preferably in a static state. Friction between powders, especially at high temperatures, generally has an unfavorable effect on fine powder type TFE-based polymers. This is because particles composed of this type of TFE-based polymer have the property of easily fibrillating even under a small shear force and losing the original stable particle structure state.

[0477] The drying temperature in step (C) is preferably 130 °C or higher, more preferably 140 °C or higher, still more preferably 150 °C or higher, still more preferably 160 °C or higher, still more preferably 180 °C or higher, still more preferably 200 °C or higher, particularly preferably 220 °C or higher, and preferably 300 °C or lower, more preferably 280 °C or lower, still more preferably 250 °C or lower, in terms of being able to more efficiently remove moisture and fluorine-containing compounds. When using vacuum, drying at a low temperature such as 60 °C or higher, 70 °C or higher, 80 °C or higher, 90 °C or higher is also preferable.

[0478] The drying time in step (C) is preferably 2 hours or longer, more preferably 5 hours or longer, still more preferably 10 hours or longer, still more preferably 15 hours or longer, in terms of being able to more efficiently remove moisture and fluorine-containing compounds. The upper limit is not particularly limited, but for example, it is preferably 100 hours, more preferably 50 hours, still more preferably 30 hours.

[0479] The wind speed in step (C) is preferably 0.01 m / s or more, more preferably 0.03 m / s or more, still more preferably 0.05 m / s or more, and even more preferably 0.1 m / s or more, in terms of more efficiently removing moisture and fluorine-containing compounds. Also, from the viewpoint of suppressing powder scattering, it is preferably 50 m / s or less, more preferably 30 m / s or less, and still more preferably 10 m / s or less.

[0480] The drying in step (C) can be carried out using an electric furnace or a steam furnace. For example, an electric furnace such as a parallel flow box-type electric furnace, a vented box-type electric furnace, a vented conveyor-type electric furnace, a band electric furnace, a radiation conveyor-type electric furnace, a fluidized bed electric furnace, a vacuum electric furnace, a stirring electric furnace, a pneumatic electric furnace, a hot air circulation electric furnace, etc., or a steam furnace corresponding to the above (a device obtained by replacing the electric furnace in the device name of each of the above electric furnaces with a steam furnace) can be used. In terms of more efficiently removing moisture and fluorine-containing compounds, a parallel flow box-type electric furnace, a vented box-type electric furnace, a vented conveyor-type electric furnace, a band electric furnace, a fluidized bed electric furnace, a hot air circulation electric furnace, and a steam furnace corresponding to the above (a device obtained by replacing the electric furnace in the device name of each of the above electric furnaces with a steam furnace) are preferred.

[0481] The drying in step (C) is preferably carried out by arranging the wet powder in a breathable container on the bottom surface and / or side surface in terms of more efficiently removing moisture and fluorine-containing compounds. The breathable container on the bottom surface and / or side surface may be any that can withstand the drying temperature, but is preferably made of a metal such as stainless steel. As the breathable container on the bottom surface and / or side surface, a tray (bat) having breathability on the bottom surface and / or side surface is preferred, and a tray (mesh tray) made of mesh on the bottom surface and / or side surface is more preferred. The mesh is preferably either a woven mesh or a punching metal. The mesh opening size is preferably 2000 μm or less (10 mesh or more according to ASTM standard), more preferably 595 μm or less (30 mesh or more), still more preferably 297 μm or less (50 mesh or more), even more preferably 177 μm or less (80 mesh or more), particularly preferably 149 μm or less (100 mesh or more), and most preferably 74 μm or less (200 mesh or more). Also, it is preferably 25 μm or more (500 mesh or less). Examples of the weaving method when the mesh is a woven wire mesh include plain weave, twill weave, plain double weave, and twill double weave. When the mesh is punching metal, the aperture ratio is preferably 10% or more, more preferably 20% or more, and still more preferably 30% or more. Also, it is preferably 95% or less.

[0482] In step (C), the amount of the wet powder disposed is preferably 10 g / cm 2 or less in terms of more efficiently removing moisture and fluorine-containing compounds, more preferably 8 g / cm 2 or less, still more preferably 5 g / cm 2 or less, particularly preferably 3 g / cm 2 or less, and preferably 0.01 g / cm 2 or more, more preferably 0.05 g / cm 2 or more, and still more preferably 0.1 g / cm 2 or more.

[0483] In step (C), the water content of the wet powder to be dried is preferably 10% by mass or more, more preferably 20% by mass or more, and still more preferably 30% by mass or more with respect to the wet powder in terms of more efficiently removing moisture and fluorine-containing compounds. Also, it is preferably 150% by mass or less, and more preferably 100% by mass or less.

[0484] In the above manufacturing method, it is also preferable to perform a treatment for reducing the heat-induced discoloration of the TFE-based polymer. This treatment may be performed on the aqueous dispersion of the TFE-based polymer, on the wet polymer after coagulation, on the polymer after drying, or a combination thereof.

[0485] Examples of the method for reducing heat-induced discoloration include, for example, a method of exposing an aqueous dispersion of a TFE-based polymer to an oxidizing agent.

[0486] In the method of the present disclosure, it is preferable that the oxidizing agent is an oxygen source. As used herein, "oxygen source" means any chemical source of available oxygen. "Available oxygen" means oxygen that can react as an oxidizing agent. The oxygen source used according to the method of the present disclosure is preferably selected from the group consisting of air, oxygen-rich gas, ozone-containing gas, and hydrogen peroxide. "Oxygen-rich gas" preferably means oxygen-enriched air, a gas mixture containing more than about 21% oxygen on a volume basis, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen on a volume basis. "Ozone-containing gas" preferably means ozone-enriched air, a gas mixture containing ozone, and pure ozone. Preferably, the content of ozone in the gas mixture is at least about 10 ppm ozone on a volume basis.

[0487] To carry out the method of the present disclosure, one of the preferred oxygen sources is an ozone-containing gas. Another preferred oxygen source for carrying out the method of the present disclosure is hydrogen peroxide. To expose the dispersion to the oxygen source, it is possible to provide the oxygen source during exposure to ultraviolet light by injecting air, oxygen-rich gas, or ozone-containing gas continuously or intermittently (preferably in a stoichiometric excess) into the dispersion. By adding a hydrogen peroxide solution, it is possible to add hydrogen peroxide to the dispersion, likewise preferably in a stoichiometric excess. The concentration of hydrogen peroxide is preferably about 0.1% by mass to about 10% by mass based on the TFE-based polymer solids in the dispersion.

[0488] Exposure of the dispersion to an oxidizing agent can be carried out by various techniques. One preferred embodiment includes the step of exposing an aqueous dispersion of a TFE-based polymer to ultraviolet light in the presence of an oxygen source. Depending on the apparatus used, the exposure to ultraviolet light may be more effective for a diluted dispersion with respect to reducing discoloration. For this reason, in order to carry out this embodiment, the aqueous dispersion of the TFE-based polymer is preferably first diluted with water to a concentration less than the concentration of the polymerized aqueous dispersion of the TFE-based polymer. Preferred concentrations are from about 2% to about 30% by weight, more preferably from about 2% to about 20% by weight.

[0489] Ultraviolet light has a wavelength range or from about 10 nm to about 400 nm and is said to have bands including UVA (315 nm - 400 nm), UVB (280 nm - 315 nm), and UVC (100 nm - 280 nm). Preferably, the ultraviolet light utilized has wavelengths in the UVC band.

[0490] Any of various types of ultraviolet lamps can be used as the ultraviolet light source. For example, underwater UV clarifier / sterilizer units sold for the purpose of controlling the growth of algae and bacteria in ponds are commercially available and can be used for carrying out this embodiment. Examples of these units include low-pressure mercury UVC lamps in a housing for water circulation. This lamp is protected by a quartz tube so that water can circulate in the housing for exposure to ultraviolet light. This type of underwater UV clarifier / sterilizer unit is sold, for example, under the brand name Pondmaster by Danner Manufacturing, Inc. of Islandia NY. For a continuous processing method, it is possible to circulate the dispersion in this type of unit to expose the dispersion to ultraviolet light. It is possible to utilize single-pass or multi-pass processing.

[0491] The dispersion can also be processed in batch operation in a container suitable for exposure to ultraviolet light in the presence of an oxygen source. In this embodiment, it is desirable that a suitably protected ultraviolet lamp be immersed in the dispersion. For example, a container commonly used for the coagulation of an aqueous dispersion of a TFE-based polymer to produce a TFE-based polymer can be used to practice the method of this embodiment by immersing an ultraviolet lamp into the dispersion held in this container. If desired, the dispersion can be circulated or agitated to facilitate exposure to ultraviolet light. If the oxygen source is the gas being considered below, circulation can be achieved or enhanced by injecting the oxygen source into the dispersion. An ultraviolet lamp equipped with a protective quartz tube of the type utilized in an in-water UV clarifier / sterilizer unit is available for immersion into the dispersion after removal from the housing. Other ultraviolet lamps, such as medium-pressure mercury lamps, can also be suitably protected for immersion into the dispersion, such as by enclosing the lamp in a quartz photowell. It is also possible to use a borosilicate glass photowell, but this may act as a filter for ultraviolet light in the UVC and UVB bands and reduce the effect. A suitable medium-pressure mercury lamp is sold by Hanovia of Fairfield, New Jersey.

[0492] As used in this embodiment, "oxygen source" means any chemical source of available oxygen. "Available oxygen" means oxygen that is capable of reacting as an oxidizing agent. The oxygen source utilized in this embodiment is preferably selected from the group consisting of air, oxygen-rich gas, ozone-containing gas, and hydrogen peroxide. "Oxygen-rich gas" means a gas mixture containing more than about 21% oxygen, preferably oxygen-enriched air, by volume, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen by volume. "Ozone-containing gas" means a gas mixture containing ozone, preferably ozone-enriched air, and pure ozone. Preferably, the ozone content in the gas mixture is at least about 10 ppm ozone by volume.

[0493] Regarding the implementation of this embodiment, one preferred oxygen source is an ozone-containing gas. Another preferred oxygen source according to the implementation of this embodiment is hydrogen peroxide. In order to have the oxygen source present in the dispersion during exposure to ultraviolet light, air, an oxygen-rich gas, or an ozone-containing gas can be injected continuously or intermittently (preferably in a stoichiometric excess) into the dispersion to provide the oxygen source during exposure to ultraviolet light. By adding a hydrogen peroxide solution, it is possible to add hydrogen peroxide to the dispersion, also preferably in a stoichiometric excess. The concentration of hydrogen peroxide is preferably about 0.1% by mass to about 10% by mass based on the TFE-based polymer solids in the dispersion.

[0494] Ultraviolet light with an oxygen source is effective at ambient or mild temperatures, and thus, typically, high temperatures are not required for the implementation of this embodiment. In a preferred form of this embodiment, the step of exposing the TFE-based polymer aqueous dispersion to ultraviolet light in the presence of an oxygen source is carried out at a temperature of about 5°C to about 70°C, preferably about 15°C to about 70°C.

[0495] The time for implementing this embodiment will vary depending on factors including the output of the ultraviolet light used, the type of oxygen source, processing conditions, etc. The preferred time according to this embodiment is about 15 minutes to about 10 hours.

[0496] Another preferred embodiment includes the step of exposing the TFE-based polymer aqueous dispersion to light having a wavelength of 10 nm to 760 nm in the presence of an oxygen source and a photocatalyst. Depending on the apparatus used, the exposure to light may be more effective for a diluted dispersion with respect to reducing discoloration. For this reason, regarding the implementation of this embodiment, the TFE-based polymer aqueous dispersion is preferably first diluted with water to a concentration lower than the concentration of the polymerized TFE-based polymer aqueous dispersion. The preferred concentration is about 2% by mass to about 30% by mass, more preferably about 2% by mass to about 20% by mass.

[0497] The light utilized in accordance with this embodiment has a wavelength range of from about 10 nm to about 760 nm. This wavelength range includes ultraviolet light having a wavelength range of from about 10 nm to about 400 nm. Ultraviolet light has a wavelength range of from about 10 nm to about 400 nm and is said to have bands including UVA (315 nm - 400 nm), UVB (280 nm - 315 nm), and UVC (100 nm - 280 nm). The light utilized in accordance with this embodiment also includes visible light having a wavelength range of from about 400 nm to about 760 nm.

[0498] Any of various types of lamps can be used as a light source. For example, underwater UV clarifier / sterilizer units sold for the purpose of controlling the growth of algae and bacteria in ponds are commercially available and can be used for the implementation of this embodiment. Examples of these units include low-pressure mercury UVC lamps in a housing for water circulation. This lamp is protected by a quartz tube such that water can circulate through the housing to expose the ultraviolet light. This type of underwater UV clarifier / sterilizer unit is sold, for example, under the brand name Pondmaster by Danner Manufacturing, Inc. of Islandia NY. For a continuous treatment method, it is possible to circulate the dispersion through this type of unit to expose the light to the dispersion. It is possible to utilize single-pass or multi-pass processing.

[0499] The dispersion can also be processed in a batch operation in a container suitable for exposure to light in the presence of an oxygen source and a photocatalyst. In this embodiment, it is desirable that a suitably protected lamp be immersed in the dispersion. For example, a container commonly used for the coagulation of an aqueous dispersion of a TFE-based polymer to produce a TFE-based polymer can be used to practice the method of this embodiment by immersing a lamp into the dispersion held in this container. If desired, the dispersion can be circulated or agitated to facilitate exposure to light. If the oxygen source is the gas being considered below, circulation can be achieved or enhanced by injecting the oxygen source into the dispersion. An ultraviolet lamp equipped with a protective quartz tube of the type utilized in an in-water UV clarifier / sterilizer unit can be utilized to be immersed in the dispersion after being removed from the housing. Other ultraviolet lamps, such as a medium-pressure mercury lamp, can also be suitably protected for immersion in the dispersion, such as by enclosing the lamp in a quartz photowell. It is also possible to use a borosilicate glass photowell, but this may act as a filter for ultraviolet light in the UVC and UVB bands and reduce the effect. A suitable medium-pressure mercury lamp is sold by Hanovia of Fairfield, New Jersey.

[0500] As used in this embodiment, "oxygen source" means any chemical source of available oxygen. "Available oxygen" means oxygen that is reactive as an oxidizing agent. The oxygen source utilized in this embodiment is preferably selected from the group consisting of air, oxygen-rich gas, ozone-containing gas, and hydrogen peroxide. "Oxygen-rich gas" means a gas mixture containing more than about 21% oxygen, preferably oxygen-enriched air, by volume, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen by volume. "Ozone-containing gas" means a gas mixture containing ozone, preferably ozone-enriched air, and pure ozone. Preferably, the ozone content in the gas mixture is at least about 10 ppm ozone by volume.

[0501] Regarding the implementation of this embodiment, one preferred oxygen source is an ozone-containing gas. Another preferred oxygen source according to the implementation of this embodiment is hydrogen peroxide. In order to have the oxygen source present in the dispersion during exposure to ultraviolet light, air, an oxygen-rich gas, or an ozone-containing gas can be injected continuously or intermittently (preferably in a stoichiometric excess) into the dispersion to provide the oxygen source during exposure to light. By adding a hydrogen peroxide solution, it is possible to add hydrogen peroxide to the dispersion as well, preferably also in a stoichiometric excess. The concentration of hydrogen peroxide is preferably about 0.1% by mass to about 10% by mass based on the TFE-based polymer solids in the dispersion.

[0502] Any of a variety of photocatalysts can be used in the implementation of this embodiment. Preferably, the photocatalyst is a heterogeneous photocatalyst. Most preferably, the heterogeneous photocatalyst is selected from the group consisting of titanium dioxide and zinc oxide. For example, titanium dioxide sold under the trade name Degussa P25, which has a primary particle size of 21 nm and is a mixture of 70% anatase and 30% rutile titanium dioxide, has been found to be an effective heterogeneous photocatalyst. The heterogeneous photocatalyst can be used by dispersing it in the dispersion prior to exposure to light. The preferred level of the heterogeneous photocatalyst is about 1 ppm to about 100 ppm based on the TFE-based polymer solids in the dispersion.

[0503] Light with an oxygen source and a photocatalyst is effective at ambient or moderate temperatures, and thus, typically, high temperatures are not required for the implementation of this embodiment. In a preferred method according to this embodiment, the step of exposing the aqueous dispersion of the TFE-based polymer to ultraviolet light in the presence of an oxygen source is carried out at a temperature of about 5°C to about 70°C, preferably about 15°C to about 70°C.

[0504] The time for implementing this embodiment will vary depending on factors including the output of the ultraviolet light used, the type of oxygen source, the processing conditions, etc. The preferred time according to this embodiment is about 15 minutes to about 10 hours.

[0505] Another preferred embodiment includes the step of exposing the aqueous dispersion of the TFE-based polymer to hydrogen peroxide. Regarding the implementation of this embodiment, the aqueous dispersion of the TFE-based polymer is preferably first diluted with water to a concentration lower than the concentration of the polymerized aqueous dispersion of the TFE-based polymer. The preferred concentration is from about 2% by weight to about 30% by weight, more preferably from about 2% by weight to about 20% by weight.

[0506] The step of exposing the aqueous dispersion of the TFE-based polymer to hydrogen peroxide is preferably carried out by adding hydrogen peroxide to the aqueous dispersion of the TFE-based polymer, preferably in an amount of from about 0.1% by weight to about 10% by weight based on the mass of the TFE-based polymer solids. Preferably, the step of exposing the aqueous dispersion of the TFE-based polymer to hydrogen peroxide is carried out at a temperature of from about 10°C to about 70°C, preferably from about 25°C to about 60°C. The time utilized for the exposure of the aqueous dispersion of the TFE-based polymer is preferably from about 1 hour to about 48 hours.

[0507] During the step of exposing the aqueous dispersion of the TFE-based polymer to hydrogen peroxide, it is also preferred for the implementation of this embodiment to inject air, an oxygen-rich gas or an ozone-containing gas into the TFE-based polymer dispersion. "Oxygen-rich gas" means a gas mixture containing more than about 21% oxygen by volume, preferably oxygen-enriched air, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen by volume. "Ozone-containing gas" means a gas mixture containing ozone, preferably ozone-enriched air, and pure ozone. Preferably, the ozone content in the gas mixture is at least about 10 ppm ozone by volume. The introduction of such a gas can be achieved by injecting the gas into the aqueous dispersion of the TFE-based polymer.

[0508] Preferably, the step of exposing the aqueous dispersion of the TFE-based polymer to hydrogen peroxide is carried out in the presence of Fe +2 , Cu +1 or Mn +2 ions. Preferably, Fe +2 , Cu +1or Mn +2 The amount of ions is from about 0.1 ppm to about 100 ppm based on the TFE-based polymer solids in the dispersion.

[0509] This method can be carried out in a continuous method. However, in the batch method, it is easy to control the time related to the exposure of the TFE-based polymer aqueous dispersion to hydrogen peroxide to achieve the desired reduction of heat-induced discoloration. Therefore, the batch method is preferred. The batch method can be carried out in any suitable tank or container made of suitable construction materials and capable of heating to heat the dispersion during processing if desired. For example, the batch method can be carried out in a container commonly used for the coagulation of TFE-based polymer aqueous dispersions, typically equipped with an impeller that can be used to stir the dispersion during processing. It is also possible to stir the dispersion by injecting air, oxygen-rich gas or ozone-containing gas.

[0510] Another preferred embodiment includes the step of exposing the TFE-based polymer aqueous dispersion to an oxidizing agent selected from the group consisting of hypochlorite and nitrite. Regarding the implementation of this embodiment, the TFE-based polymer aqueous dispersion is preferably first diluted with water to a concentration lower than the concentration of the polymerized TFE-based polymer aqueous dispersion. The preferred concentration is from about 2% by mass to about 30% by mass, more preferably from about 2% by mass to about 20% by mass.

[0511] The step of exposing the aqueous dispersion of the TFE-based polymer to an oxidizing agent selected from the group consisting of hypochlorite and nitrite is preferably carried out by adding the oxidizing agent to the aqueous dispersion of the TFE-based polymer in an amount of preferably about 0.05% by mass to about 5% by mass based on the mass of the TFE-based polymer solid content. Preferred hypochlorites for addition to the dispersion are sodium hypochlorite or potassium hypochlorite. Sodium hypochlorite or potassium hypochlorite is preferably used in an amount of about 0.05% by mass to about 5% by mass based on the mass of the TFE-based polymer solid content. However, when the aqueous medium of the dispersion is sufficiently alkaline, such as by containing sodium hydroxide, the hypochlorite can also be generated in situ by injecting chlorine gas into the dispersion. Preferred nitrites for addition to the dispersion are sodium nitrite, potassium nitrite, and ammonium nitrite. Sodium nitrite, potassium nitrite, and ammonium nitrite are preferably used in an amount of about 0.5% by mass to about 5% by mass based on the mass of the TFE-based polymer solid content.

[0512] Preferably, the step of exposing the aqueous dispersion of the TFE-based polymer to the oxidizing agent is carried out at a temperature of about 10°C to about 70°C. The exposure time with the aqueous dispersion of the TFE-based polymer is preferably about 5 minutes to about 3 hours.

[0513] During the step of exposing the aqueous dispersion of the TFE-based polymer to the oxidizing agent, it is also preferable for the implementation of this embodiment to introduce air, an oxygen-rich gas, or an ozone-containing gas into the TFE-based polymer dispersion. "Oxygen-rich gas" means a gas mixture containing more than about 21% oxygen by volume, which is preferably enriched air, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen by volume. "Ozone-containing gas" means a gas mixture containing ozone, which is preferably ozone-enriched air, and pure ozone. Preferably, the content of ozone in the gas mixture is at least about 10 ppm ozone by volume. The introduction of such a gas can be achieved by injecting such a gas into the aqueous dispersion of the TFE-based polymer.

[0514] This embodiment can also be implemented in a continuous process, but in a batch process, it is easier to control the time of exposure of the hypochlorite or nitrite to the aqueous dispersion of the TFE-based polymer to achieve the desired reduction in heat-induced discoloration. Therefore, the batch process is preferred. The batch process can be carried out in any suitable tank or container made of suitable construction materials and capable of heating, if desired, to heat the dispersion during processing. For example, the batch process can be carried out in a container commonly used for the coagulation of aqueous dispersions of TFE-based polymers, typically equipped with an impeller that can be used to stir the dispersion during processing. It is also possible to stir the dispersion by injecting air, an oxygen-rich gas, or an ozone-containing gas.

[0515] Another preferred embodiment includes the step of adjusting the pH of the aqueous medium of the aqueous dispersion of the TFE-based polymer to above about 8.5 and the step of exposing the aqueous dispersion of the TFE-based polymer to an oxygen source. Regarding the implementation of this embodiment, the aqueous dispersion of the TFE-based polymer is preferably first diluted with water to a concentration lower than the concentration of the polymerized aqueous dispersion of the TFE-based polymer. Preferred concentrations are from about 2% to about 30% by weight, more preferably from about 2% to about 20% by weight.

[0516] The pH of the aqueous dispersion of the TFE-based polymer is preferably adjusted to about 8.5 to about 11. More preferably, the pH of the aqueous medium of the aqueous dispersion of the TFE-based polymer is adjusted to about 9.5 to about 10.

[0517] Regarding the implementation of this embodiment, the pH can be adjusted by adding a base that is strongly basic enough to adjust the pH of the aqueous dispersion of the TFE-based polymer to the desired level and is otherwise compatible with the processing of the dispersion and the final use properties of the resulting TFE-based polymer. Preferred bases are alkali metal hydroxides such as sodium hydroxide or potassium hydroxide. Ammonium hydroxide can also be used.

[0518] As used in this embodiment, "oxygen source" means any chemical source of available oxygen. "Available oxygen" means oxygen that can react as an oxidizing agent. The oxygen source used in this embodiment is preferably selected from the group consisting of air, oxygen-rich gas, ozone-containing gas, and hydrogen peroxide. "Oxygen-rich gas" preferably means oxygen-enriched air, a gas mixture containing more than about 21% oxygen on a volume basis, and pure oxygen. Preferably, the oxygen-rich gas contains at least about 22% oxygen on a volume basis. "Ozone-containing gas" preferably means ozone-enriched air, a gas mixture containing ozone, and pure ozone. Preferably, the ozone content in the gas mixture is at least about 10 ppm ozone on a volume basis.

[0519] Regarding the implementation of this embodiment, one of the preferred oxygen sources is an ozone-containing gas. Another preferred oxygen source according to the implementation of this embodiment is hydrogen peroxide. In order to expose the dispersion to the oxygen source, it is possible to inject air, oxygen-rich gas, or ozone-containing gas continuously or intermittently (preferably in a stoichiometric excess) into the dispersion. By adding a hydrogen peroxide solution, it is possible to add hydrogen peroxide to the dispersion, also preferably in a stoichiometric excess. The concentration of hydrogen peroxide is preferably about 0.1% by mass to about 10% by mass based on the TFE-based polymer solids in the dispersion.

[0520] Preferably, the step of exposing the aqueous dispersion of the TFE-based polymer to the oxygen source is carried out at a temperature of about 10°C to about 95°C, more preferably about 20°C to about 80°C, and most preferably about 25°C to about 70°C. The time used for exposing the aqueous dispersion of the TFE-based polymer to the oxygen source is preferably about 5 minutes to about 24 hours.

[0521] This method can also be carried out in a continuous manner, but in the batch method, it is easy to control the time related to the exposure of the TFE-based polymer aqueous dispersion and hydrogen peroxide to achieve the desired reduction in heat-induced discoloration. Therefore, the batch method is preferred. The batch method can be carried out in any suitable tank or container made of appropriate constituent materials and capable of being heated to heat the dispersion during processing if desired. For example, the batch method can be carried out in a container commonly used for the coagulation of a TFE-based polymer aqueous dispersion, typically equipped with an impeller that can be used to stir the dispersion during processing. It is also possible to stir the dispersion by injecting air, an oxygen-rich gas, or an ozone-containing gas.

[0522] As a method for reducing heat-induced discoloration, a method of bringing an aqueous dispersion of a TFE-based polymer into contact with an adsorbent is also preferred.

[0523] The term "adsorbent" means a material that can remove a compound that causes heat-induced discoloration of a TFE-based polymer, such as a hydrocarbon surfactant, when in contact with an aqueous dispersion of the TFE-based polymer. The adsorbent useful for carrying out the method of the present disclosure may be in any of various physical forms, such as particles or a larger structure having porosity that provides a surface area sufficient to be effective as an adsorbent. The term "adsorbent" is not intended to be limited in any way by the mechanism or mode of operation, and the adsorbent can operate by adsorption, absorption, or other mechanisms that achieve the removal of compounds that cause heat-induced discoloration of the TFE-based polymer by contacting the aqueous dispersion of the TFE-based polymer.

[0524] The adsorbent is preferably in the form of particles that result in an increased surface area. This is because an increase in surface area generally increases the adsorption rate of the adsorbent and / or the adsorption capacity of the color-forming compound. The particulate adsorbent can have any shape such as beads, spheres, cylinders, rods, etc., and can also include mixtures of such shapes. The adsorbent particles are preferably porous to further increase the surface area. The porous particles allow for the use of a larger particle size, making handling easier and enabling use as an adsorbent. Depending on the type of adsorbent and the porosity of the particles, the particle size can vary, but preferably the number average particle size ranges from about 0.05 mm to about 20 mm. Depending on the type, the surface area of the adsorbent can vary widely, but preferably ranges from about 10 m 2 / g to about 3000 m 2 / g.

[0525] Adsorbents useful in the practice of the methods of the present disclosure include activated carbon, ion exchange resins, silica gel, polymeric adsorbents, diatomaceous earth, zeolites, clays, and bonded silica. Preferred adsorbents are activated carbon, ion exchange resins, silica gel, polymeric adsorbents, diatomaceous earth and zeolites. One particularly preferred...

Claims

1. A tetrafluoroethylene-based polymer composition for use in a binder for an electrochemical device, the tetrafluoroethylene-based polymer composition comprising a tetrafluoroethylene-based polymer that is a copolymer of tetrafluoroethylene and a monomer having a polar group, and having fibrillation ability.

2. The tetrafluoroethylene polymer composition according to claim 1, wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine-containing monomer having a carboxyl group, a non-fluorine-containing monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6): CH ２ =CR １１ -CO-O-R １３ (10-1) (In the formula, R １１ is a hydrogen atom or an alkyl group, R １３ is a hydrogen atom or an alkyl group. CX ２ =CY(-CZ ２ -O-Rf-Y ３ )(5) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z may be the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.) CX ２ =CY(-O-Rf-Y ３ )(6) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.)

3. 3. The tetrafluoroethylene polymer composition according to claim 1, in the form of a powder.

4. 3. The tetrafluoroethylene polymer composition according to claim 1 or 2, which is used as a binder for lithium ion secondary batteries and is in the form of a powder.

5. A binder for electrochemical devices consisting essentially of a tetrafluoroethylene-based polymer composition, the tetrafluoroethylene-based polymer composition containing a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, the binder for electrochemical devices having fibrillation ability.

6. 6. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition has an endothermic peak temperature of 327°C or higher and 350°C or lower.

7. 7. The binder for electrochemical devices according to claim 5, wherein the standard specific gravity of the tetrafluoroethylene polymer composition is 2.280 or less.

8. 7. The binder for electrochemical devices according to claim 5, wherein the 1.0% mass loss temperature of the tetrafluoroethylene polymer composition is 492° C. or lower.

9. 7. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition has a heat stability index (TII) of 20 or more.

10. 7. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition further contains a fluorine-containing compound having a hydrophilic group.

11. The hydrophilic group is -SO ３ M ａ , -SO ２ M ａ , -OSO ２ M ａ , -PO ３ M ａ , -COOM ａ , -OCOM ａ , and -O.M. ａ (In the formula, M ａ is -H, a metal atom, -NR ２ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium; R ２ The binder for electrochemical devices according to claim 10, wherein the binder is at least one selected from the group consisting of:

12. 7. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition contains a compound represented by the following general formula (1): General formula (1): (H-(CF ２ ) ｍ－１ -COO) ｐ M １ (In the formula, m is 4 to 20. １ is H, a metal atom, NR ５ ４ (R ５ may be the same or different and are H or an organic group having 1 to 10 carbon atoms), an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent. p is 1 or 2.

13. 7. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition contains a compound represented by the following general formula (2): General formula (2): (H-(CF ２ ) ｎ -SO ３ ) ｑ M ２ (wherein n is 4 to 20. M ２ is H, metal atom, NR ５ ４ (R ５ is the same as above), optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. q is 1 or 2.

14. 7. The binder for electrochemical devices according to claim 5, wherein the tetrafluoroethylene polymer composition is substantially free of a compound represented by the following general formula (3): General formula (3): (H-(CF ２ ) ８ -SO ３ ) ｑ M ２ (In the formula, M ２ is H, metal atom, NR ５ ４ (R ５ may be the same or different and are H or an organic group having 1 to 10 carbon atoms), an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent; and q is 1 or 2.

15. 7. The binder for electrochemical devices according to claim 5, wherein the monomer having a polar group is a non-fluorine-containing monomer having a polar group.

16. 7. The binder for electrochemical devices according to claim 5, wherein the monomer having a polar group is a monomer represented by the following general formula (10): General formula (10): CH ２ =CR １１ -L １１ -R １２ (In the formula, R １１ represents a hydrogen atom or an alkyl group. １１ represents a single bond, -CO-O-*, -O-CO-* or -O-. * represents R １２ represents the bonding position with １２ represents a hydrogen atom, an alkyl group, or a nitrile group.

17. The binder for electrochemical devices according to claim 5 or 6, wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine-containing monomer having a carboxyl group, a non-fluorine-containing monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6): CH ２ =CR １１ -CO-O-R １３ (10-1) (In the formula, R １１ is a hydrogen atom or an alkyl group, R １３ is a hydrogen atom or an alkyl group. CX ２ =CY(-CZ ２ -O-Rf-Y ３ )(5) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z may be the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.) CX ２ =CY(-O-Rf-Y ３ )(6) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.)

18. 7. The binder for electrochemical devices according to claim 5 or 6, which is a binder for lithium ion secondary batteries and is in the form of a powder.

19. A tetrafluoroethylene-based polymer composition used as a binder for an electrochemical device, the tetrafluoroethylene-based polymer composition comprising a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, the tetrafluoroethylene-based polymer composition having a fibrillated portion and an endothermic peak temperature of 327°C or higher and 350°C or lower.

20. The tetrafluoroethylene polymer composition according to claim 19, wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine-containing monomer having a carboxyl group, a non-fluorine-containing monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6): CH ２ =CR １１ -CO-O-R １３ (10-1) (In the formula, R １１ is a hydrogen atom or an alkyl group, R １３ is a hydrogen atom or an alkyl group. CX ２ =CY(-CZ ２ -O-Rf-Y ３ )(5) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z may be the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.) CX ２ =CY(-O-Rf-Y ３ )(6) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.)

21. The tetrafluoroethylene polymer composition according to claim 19 or 20, which is used as a binder for a lithium ion secondary battery and is in the form of a sheet.

22. A binder for electrochemical devices consisting essentially of a tetrafluoroethylene-based polymer composition, the tetrafluoroethylene-based polymer composition containing a tetrafluoroethylene-based polymer which is a copolymer of tetrafluoroethylene and a monomer having a polar group, having fibrillated portions, and having an endothermic peak temperature of 327°C or higher and 350°C or lower.

23. The binder for electrochemical devices according to claim 22, wherein the monomer having a polar group is at least one selected from the group consisting of a non-fluorine-containing monomer having a carboxyl group, a non-fluorine-containing monomer having a sulfo group, a monomer represented by the following formula (10-1), a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6): CH ２ =CR １１ -CO-O-R １３ (10-1) (In the formula, R １１ is a hydrogen atom or an alkyl group, R １３ is a hydrogen atom or an alkyl group. CX ２ =CY(-CZ ２ -O-Rf-Y ３ )(5) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z may be the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.) CX ２ =CY(-O-Rf-Y ３ )(6) (In the formula, X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; and Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is a hydrophilic group.)

24. 24. The binder for electrochemical devices according to claim 22 or 23, which is a binder for lithium ion secondary batteries and is in the form of a sheet.

25. 27. An electrode mixture comprising the tetrafluoroethylene polymer composition according to claim 1, 2, 19 or 20, or the binder for electrochemical devices according to claim 5, 6, 22 or 23, and an electrode active material.

26. The electrode mixture according to claim 25, which is in the form of a sheet.

27. 27. An electrode comprising the tetrafluoroethylene polymer composition according to claim 1, 2, 19 or 20, or the binder for electrochemical devices according to claim 5, 6, 22 or 23, an electrode active material, and a current collector.

28. A secondary battery comprising the electrode according to claim 27.

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