Method for producing aqueous fluoropolymer dispersion, and aqueous fluoropolymer dispersion

Abstract

The invention relates to a method for producing an aqueous fluoropolymer dispersion and an aqueous fluoropolymer dispersion. A method for producing a purified aqueous fluoropolymer dispersion, characterized by comprising a step (A) in which an aqueous fluoropolymer dispersion obtained using a hydrocarbon-based surfactant is brought into contact with an anion exchange resin (A) or a synthetic adsorbent, the anion exchange resin (A) having the following general formula (A1):-N + R1R2R3X-(wherein R1 represents a hydrogen atom, R2 represents a hydrogen atom, and X represents a hydrogen atom; r1, R2, and R3 are the same or different hydrogen atoms or organic groups, and at least one of R1, R2, and R3 is an organic group having 3 or more carbon atoms. X is a counter ion. ) or (A2)-NR4R5 (In the formula, R4 and R5 are the same or different and are hydrogen atoms or organic groups, and at least one of R4 and R5 is an organic group having 2 or more carbon atoms. ) an ion exchange group represented by formula (1).

Description

[0001] This application is a divisional application. The Chinese national application number of the original application is 202080030440.5, the application date is April 27, 2020, and the name of the invention is “Method for manufacturing aqueous fluoropolymer dispersion and aqueous fluoropolymer dispersion”. Technical Field

[0002] The present invention relates to a method for producing an aqueous fluoropolymer dispersion and the aqueous fluoropolymer dispersion. Background Art

[0003] When producing a fluorinated polymer by emulsion polymerization, a fluorinated anionic surfactant is used. Recently, the use of a hydrocarbon surfactant in place of the fluorinated anionic surfactant has been proposed (see, for example, Patent Documents 1 to 3).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent No. 9,255,164

[0007] Patent Document 2: U.S. Patent No. 8,563,670

[0008] Patent Document 3: U.S. Patent No. 9,074,025 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The present invention provides a method for producing an aqueous fluoropolymer dispersion that can reduce the amount of specific fluorinated compounds even when a hydrocarbon-based surfactant is used. Furthermore, the present invention provides a novel aqueous fluoropolymer dispersion having a reduced amount of specific fluorinated compounds.

[0011] Means for solving problems

[0012] The present invention relates to a method for producing a purified fluoropolymer aqueous dispersion, characterized in that the method comprises a step A of contacting an aqueous fluoropolymer dispersion obtained using a hydrocarbon-based surfactant with an anion exchange resin A or a synthetic adsorbent, wherein the anion exchange resin A has the following general formula (A1):

[0013] -N + R 1 R 2 R 3 X -

[0014] (Where R 1 、R 2 and R 3The same or different ones are hydrogen atoms or organic groups, R 1 、R 2 and R 3 At least one of them is an organic group having 3 or more carbon atoms. X is a counter ion. ) or the following general formula (A2):

[0015] -NR 4 R 5

[0016] (Where R 4 and R 5 The same or different ones are hydrogen atoms or organic groups, R 4 and R 5 At least one of them is an organic group having 2 or more carbon atoms. ) is an ion exchange group represented by.

[0017] In the general formula (A1), R 1 、R 2 and R 3 At least one of them is an organic group having 4 or more carbon atoms. In the general formula (A1), it is also preferred that R 1 、R 2 and R 3 It is an organic group having 2 or more carbon atoms.

[0018] The pore volume of the synthetic adsorbent is preferably 0.6 to 2.5 cm 3 / g.

[0019] In the production method of the present invention, step A is preferably performed two or more times.

[0020] The production method of the present invention preferably further comprises a step B of contacting the aqueous fluoropolymer dispersion with an anion exchange resin B, wherein the anion exchange resin B is different from the anion exchange resin A described above.

[0021] The anion exchange resin B preferably has the following general formula (B1):

[0022] -N + (CH3)3X -

[0023] (wherein X represents a counter ion.) The ion exchange group represented by, or the following general formula (B2):

[0024] -N + (CH3)2(C2H4OH)X -

[0025] (wherein X represents a counter ion.) The ion exchange group represented by.

[0026] The above-mentioned step B is preferably performed before step A.

[0027] The production method of the present invention preferably further comprises a step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion after step A to perform phase separation and concentration. More preferably, step C is performed two or more times.

[0028] In the first step C, the phase separation concentration is preferably performed by heating the aqueous fluoropolymer dispersion at a temperature 5° C. or higher lower than the cloud point of the nonionic surfactant and then allowing it to stand to separate into a supernatant phase and a concentrated phase.

[0029] In the second step C, the phase separation concentration is preferably performed by heating the fluoropolymer aqueous dispersion at a temperature 5°C or higher lower than the cloud point of the nonionic surfactant and then allowing it to stand to separate into a supernatant phase and a concentrated phase.

[0030] The present invention also relates to an aqueous fluoropolymer dispersion comprising a fluoropolymer and water, characterized in that the dispersion comprises a compound represented by the following general formula (1), wherein the total content of the compound represented by the following general formula (1) is 1000 ppb or less relative to the fluoropolymer.

[0031] General formula (1): (H-(CF2) m -COO) p M 1

[0032] (where m is 3 to 19, M 1 H, metal atoms, NR 5 4(R 5 (may be the same or different and be H or an organic group having 1 to 10 carbon atoms), an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. p is 1 or 2.)

[0033] Effects of the Invention

[0034] The production method of the present invention, having the above-mentioned configuration, can obtain an aqueous fluoropolymer dispersion having a reduced amount of a specific fluorinated compound even when a hydrocarbon-based surfactant is used. DETAILED DESCRIPTION

[0035] Before describing the present invention in detail, several terms used in this specification are defined or explained.

[0036] In this specification, fluororesin is a partially crystalline fluoropolymer and a fluoroplastic. Fluororesin has a melting point and thermoplastic properties, and can be melt-processable or non-melt-processable.

[0037] In this specification, melt processability means that the polymer can be melted and processed using existing processing equipment such as extruders and injection molding machines. Therefore, the melt flow rate of melt-processable fluororesins is generally 0.01 to 500 g / 10 min as measured by the measurement method described below.

[0038] In this specification, fluororubber is an amorphous fluoropolymer. "Amorphous" means that the melting peak (ΔH) observed in differential scanning calorimetry (DSC) (heating rate 10°C / min) or differential thermal analysis (DTA) (heating rate 10°C / min) of the fluoropolymer is 4.5 J / g or less. Fluororubber exhibits elastomeric properties through crosslinking. Elastomeric properties refer to the ability to stretch a polymer and maintain its original length even when the force required to stretch it is no longer applied.

[0039] In this specification, partially fluorinated rubber refers to a fluoropolymer comprising fluorinated monomer units, wherein the content of perfluorinated monomer units is less than 90 mol % relative to the total polymer units, and having a glass transition temperature of 20° C. or lower and a melting peak (ΔH) of 4.5 J / g or lower.

[0040] In this specification, perfluororubber (perfluoroelastomer) refers to a fluoropolymer containing perfluoromonomer units at a content of 90 mol% or more relative to all polymerized units, having a glass transition temperature of 20°C or less, a melting peak (ΔH) of 4.5 J / g or less, and a fluorine atom concentration of 71% by mass or more. In this specification, the fluorine atom concentration in a fluoropolymer is calculated (mass %) based on the types and contents of the monomers constituting the fluoropolymer.

[0041] In this specification, a perfluorinated monomer refers to a monomer whose molecule contains no carbon-hydrogen bonds. Such perfluorinated monomers may have, in addition to carbon and fluorine atoms, some of the fluorine atoms bonded to carbon atoms replaced by chlorine atoms. Alternatively, such monomers may have, in addition to carbon atoms, nitrogen, oxygen, sulfur, phosphorus, boron, or silicon atoms. Preferred perfluorinated monomers are those in which all hydrogen atoms are replaced by fluorine atoms. These perfluorinated monomers do not include monomers that provide crosslinking sites.

[0042] The monomer providing a crosslinking site refers to a monomer having a crosslinkable group that provides a crosslinking site for forming a crosslink with a curing agent to the fluoropolymer (cure site monomer).

[0043] In this specification, the content of each monomer constituting the fluoropolymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

[0044] In this specification, an "organic group" refers to a group containing one or more carbon atoms, or a group formed by removing one hydrogen atom from an organic compound.

[0045] Examples of the "organic group" include

[0046] an alkyl group which may or may not have one or more substituents,

[0047] an alkenyl group which may have one or more substituents,

[0048] Alkynyl which may have one or more substituents,

[0049] a cycloalkyl group which may have one or more substituents,

[0050] a cycloalkenyl group which may have one or more substituents,

[0051] a cycloalkadienyl group which may have one or more substituents,

[0052] an aryl group which may or may not have one or more substituents,

[0053] an aralkyl group which may have one or more substituents,

[0054] a non-aromatic heterocyclic group which may or may not have one or more substituents,

[0055] a heteroaryl group which may or may not have one or more substituents,

[0056] cyano,

[0057] Formyl,

[0058] RaO-、

[0059] RaCO-,

[0060] RaSO2-,

[0061] RaCOO-、

[0062] RaNRaCO-、

[0063] RaCONRa-,

[0064] RaOCO-,

[0065] RaOSO2- and

[0066] RaNRbSO2-

[0067] (In these formulas, Ra is independently

[0068] an alkyl group which may or may not have one or more substituents,

[0069] an alkenyl group which may have one or more substituents,

[0070] Alkynyl which may have one or more substituents,

[0071] a cycloalkyl group which may have one or more substituents,

[0072] a cycloalkenyl group which may have one or more substituents,

[0073] a cycloalkadienyl group which may have one or more substituents,

[0074] an aryl group which may or may not have one or more substituents,

[0075] an aralkyl group which may have one or more substituents,

[0076] a non-aromatic heterocyclic group which may or may not have one or more substituents, or

[0077] a heteroaryl group which may or may not have one or more substituents,

[0078] Rb is independently H or an alkyl group which may have one or more substituents).

[0079] As the organic group, an alkyl group which may have one or more substituents is preferable.

[0080] In addition, in this specification, "substituent" refers to a group that can be substituted. Examples of such "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl group, an aliphatic sulfonyloxy group, an aromatic sulfonyloxy group, a heterocyclic sulfonyloxy group, a sulfamoyl group, an aliphatic sulfonamide group, an aromatic sulfonamide group, a heterocyclic sulfonamide group, an amino group, an aliphatic amino group, an aromatic amino group, a heterocyclic amino group, an aliphatic oxycarbonylamino group, an aromatic oxycarbonylamino group, a heterocyclic oxycarbonylamino group, an aliphatic sulfinyl group, an aromatic sulfinyl group, an aliphatic thio group, an aromatic thio group, a hydroxyl group, a cyano group, a sulfo group, a carboxyl group, an aliphatic oxyamino group, an aromatic oxyamino group, a carbamoylamino group, a sulfamoylamino group, a halogen atom, a sulfamoylcarbamoyl group, a carbamoylsulfamoyl group, a dialiphatic oxyphosphinyl group, and a diaromatic oxyphosphinyl group.

[0081] The aliphatic group may be saturated or unsaturated, and may have a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the aliphatic group include an alkyl group having a total carbon number of 1 to 8, preferably 1 to 4, such as a methyl group, an ethyl group, a vinyl group, a cyclohexyl group, and a carbamoylmethyl group.

[0082] The aromatic group may include, for example, a nitro group, a halogen atom, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the aromatic group include aryl groups having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms in total, such as phenyl, 4-nitrophenyl, 4-acetylaminophenyl, and 4-methylsulfonylphenyl.

[0083] The heterocyclic group may have a halogen atom, a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the heterocyclic group include a 5- to 6-membered heterocyclic ring having a total carbon number of 2 to 12, preferably 2 to 10, such as a 2-tetrahydrofuranyl group and a 2-pyrimidinyl group.

[0084] The acyl group may include an aliphatic carbonyl group, an arylcarbonyl group, a heterocyclic carbonyl group, a hydroxyl group, a halogen atom, an aromatic group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the acyl group include an acyl group having a total carbon number of 2 to 8, preferably 2 to 4, such as an acetyl group, a propionyl group, a benzoyl group, and a 3-pyridinecarbonyl group.

[0085] The acylamino group may have an aliphatic group, an aromatic group, a heterocyclic group, and the like, and may have, for example, an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propionylamino group, and the like. Examples of the acylamino group include acylamino groups having a total carbon number of 2 to 12, preferably 2 to 8, and alkylcarbonylamino groups having a total carbon number of 2 to 8, such as acetylamino groups, benzoylamino groups, 2-pyridinecarbonylamino groups, and propionylamino groups.

[0086] The aliphatic oxycarbonyl group may be saturated or unsaturated, and may have a hydroxyl group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the aliphatic oxycarbonyl group include alkoxycarbonyl groups having a total carbon number of 2 to 8, preferably 2 to 4, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a tert-butoxycarbonyl group.

[0087] The carbamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, etc. Examples of the carbamoyl group include unsubstituted carbamoyl groups and alkylcarbamoyl groups having 2 to 9 carbon atoms in total, and preferably include unsubstituted carbamoyl groups and alkylcarbamoyl groups having 2 to 5 carbon atoms in total, such as N-methylcarbamoyl, N,N-dimethylcarbamoyl, and N-phenylcarbamoyl groups.

[0088] The aliphatic sulfonyl group may be saturated or unsaturated, and may have a hydroxyl group, an aromatic group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the aliphatic sulfonyl group include alkylsulfonyl groups having a total carbon number of 1 to 6, preferably a total carbon number of 1 to 4, such as a methylsulfonyl group.

[0089] The aromatic sulfonyl group may have a hydroxyl group, an aliphatic group, an aliphatic oxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thiol group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, etc. Examples of the aromatic sulfonyl group include an arylsulfonyl group having 6 to 10 carbon atoms, such as a benzenesulfonyl group.

[0090] The amino group may have an aliphatic group, an aromatic group, a heterocyclic group, or the like.

[0091] The acylamino group may include, for example, acetylamino, benzoylamino, 2-pyridinecarbonylamino, propionylamino, etc. Examples of the acylamino group include acylamino groups having a total carbon number of 2 to 12, preferably acylamino groups having a total carbon number of 2 to 8, and more preferably alkylcarbonylamino groups having a total carbon number of 2 to 8, such as acetylamino, benzoylamino, 2-pyridinecarbonylamino, propionylamino, etc.

[0092] Examples of the aliphatic sulfonamide group, aromatic sulfonamide group, and heterocyclic sulfonamide group include methanesulfonamide group, benzenesulfonamide group, and 2-pyridinesulfonamide group.

[0093] The sulfamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, etc. Examples of the sulfamoyl group include a sulfamoyl group, an alkylsulfamoyl group having 1 to 9 total carbon atoms, a dialkylsulfamoyl group having 2 to 10 total carbon atoms, an arylsulfamoyl group having 7 to 13 total carbon atoms, and a heterocyclic sulfamoyl group having 2 to 12 total carbon atoms. More preferred examples include a sulfamoyl group, an alkylsulfamoyl group having 1 to 7 total carbon atoms, a dialkylsulfamoyl group having 3 to 6 total carbon atoms, an arylsulfamoyl group having 6 to 11 total carbon atoms, and a heterocyclic sulfamoyl group having 2 to 10 total carbon atoms, such as a sulfamoyl group, a methylsulfamoyl group, an N,N-dimethylsulfamoyl group, a phenylsulfamoyl group, and a 4-pyridylsulfamoyl group.

[0094] The aliphatic oxy group may be saturated or unsaturated, and may include methoxy, ethoxy, isopropoxy, cyclohexyloxy, methoxyethoxy, etc. Examples of the aliphatic oxy group include alkoxy groups having a total carbon number of 1 to 8, preferably 1 to 6, such as methoxy, ethoxy, isopropoxy, cyclohexyloxy, methoxyethoxy, etc.

[0095] The aromatic amino group and heterocyclic amino group may have an aliphatic group, an aliphatic oxy group, a halogen atom, a carbamoyl group, a heterocyclic group condensed with the aromatic group, or an aliphatic oxycarbonyl group. Preferably, the aromatic amino group may have an aliphatic group having 1 to 4 carbon atoms in total, an aliphatic oxy group having 1 to 4 carbon atoms in total, a halogen atom, a carbamoyl group having 1 to 4 carbon atoms in total, a nitro group, or an aliphatic oxycarbonyl group having 2 to 4 carbon atoms in total.

[0096] The aliphatic thiol group may be saturated or unsaturated, and examples thereof include alkylthio groups having 1 to 8 total carbon atoms, more preferably 1 to 6 total carbon atoms, such as methylthio, ethylthio, carbamoylmethylthio, and tert-butylthio.

[0097] The carbamoylamino group may have an aliphatic group, an aryl group, a heterocyclic group, etc. Examples of the carbamoylamino group include carbamoylamino groups, alkylcarbamoylamino groups having a total of 2 to 9 carbon atoms, dialkylcarbamoylamino groups having a total of 3 to 10 carbon atoms, arylcarbamoylamino groups having a total of 7 to 13 carbon atoms, and heterocyclic carbamoylamino groups having a total of 3 to 12 carbon atoms. Preferred examples include carbamoylamino groups, alkylcarbamoylamino groups having a total of 2 to 7 carbon atoms, dialkylcarbamoylamino groups having a total of 3 to 6 carbon atoms, arylcarbamoylamino groups having a total of 7 to 11 carbon atoms, and heterocyclic carbamoylamino groups having a total of 3 to 10 carbon atoms, such as carbamoylamino groups, methylcarbamoylamino groups, N,N-dimethylcarbamoylamino groups, phenylcarbamoylamino groups, and 4-pyridylcarbamoylamino groups.

[0098] In this specification, ranges expressed by endpoints include all values ​​within the range (for example, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0099] In this specification, the phrase "at least 1" includes all numerical values ​​greater than or equal to 1 (for example, at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

[0100] In this specification, unless otherwise specified, ppm and ppb mean values ​​calculated on a mass basis.

[0101] Next, the production method of the present invention and the aqueous fluoropolymer dispersion of the present invention are described in detail.

[0102] The method for producing a purified fluoropolymer aqueous dispersion of the present invention comprises a step A of contacting an aqueous fluoropolymer dispersion obtained using a hydrocarbon-based surfactant with an anion exchange resin A or a synthetic adsorbent, wherein the anion exchange resin A has the following general formula (A1):

[0103] -N + R 1 R 2 R 3 X -

[0104] (Where R 1 、R 2 and R 3 The same or different ones are hydrogen atoms or organic groups, R 1 、R 2 and R 3 At least one of them is an organic group having 3 or more carbon atoms. X represents a counter ion. ) or the following general formula (A2):

[0105] -NR 4 R 5

[0106] (Where R 4 and R 5 The same or different ones are hydrogen atoms or organic groups, R 4 and R 5 At least one of the cation exchange groups is an organic group having 2 or more carbon atoms. The specific fluorinated compound can be effectively removed from the aqueous fluoropolymer dispersion by contacting the aqueous fluoropolymer dispersion with the specific anion exchange resin or synthetic adsorbent.

[0107] In the production method of the present invention, the "purified fluoropolymer aqueous dispersion" is not limited as long as it is an aqueous fluoropolymer dispersion obtained through at least the above-mentioned step A.

[0108] In this specification, unless otherwise specified, "aqueous fluoropolymer dispersion" refers to the aqueous fluoropolymer dispersion supplied to the above-mentioned step A (and further to the later-described steps B and C, etc., as needed).

[0109] In the general formula (A1), R 1 、R 2 and R 3 R is the same or different and is a hydrogen atom or an organic group. 1 、R 2 and R 3All of them may be organic groups, or one may be a hydrogen atom and two may be organic groups. In addition, two may be hydrogen atoms and one may be an organic group. The number of carbon atoms in the organic group is 1 or more. The number of carbon atoms in the organic group is preferably 2 or more. 1 、R 2 and R 3 One preferred embodiment is an organic group having 2 or more carbon atoms.

[0110] In the general formula (A1), the above R 1 、R 2 and R 3 At least one of them is an organic group having 3 or more carbon atoms. 1 、R 2 and R 3 In the formula (R), one may be an organic group having 3 or more carbon atoms and two may be hydrogen atoms or organic groups having 1 or 2 carbon atoms. Alternatively, two may be organic groups having 3 or more carbon atoms and one may be a hydrogen atom or an organic group having 1 or 2 carbon atoms. 1 、R 2 and R 3 All of them may be organic groups having 3 or more carbon atoms.

[0111] The above R 1 、R 2 and R 3 In the formula (I), the number of carbon atoms of the organic group is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less. The number of carbon atoms of the organic group may be 5 or less.

[0112] In the general formula (A1), R 1 、R 2 and R 3 At least one of the groups is an organic group having at least 4 carbon atoms. By adopting such a configuration, specific fluorine-containing compounds can be removed more efficiently.

[0113] The above R 1 、R 2 and R 3 The organic group in is preferably an alkyl group, an alkanol group or an alkenyl group, more preferably an alkyl group or an alkanol group, further preferably an alkyl group.

[0114] It should be noted that in this specification, "alkyl" is a general term for the group remaining after removing one hydrogen atom from an aliphatic saturated hydrocarbon, and includes linear or branched alkyl groups having 1 or more carbon atoms or cyclic alkyl groups having 3 or more carbon atoms.

[0115] In this specification, "alkanol group" is a general term for the group remaining after removing one hydrogen atom from an alkanol, and includes linear or branched alkanol groups having 1 or more carbon atoms and cyclic alkanol groups having 3 or more carbon atoms.

[0116] Preferably, the above R 1 、R 2 and R 3 are identical or different alkyl groups having 2 or more carbon atoms or alkanol groups having 1 or more carbon atoms, and R 1 、R 2 and R 3 At least one of them is an alkyl group having 3 or more carbon atoms.

[0117] The above R 1 、R 2 and R 3 are identical or different alkyl groups having 2 or more carbon atoms or alkanol groups having 2 or more carbon atoms, and R 1 、R 2 and R 3 One of the more preferred embodiments is that at least one of the groups is an alkyl group having 3 or more carbon atoms.

[0118] In addition, the above R 1 、R 2 and R 3 are identical or different alkyl groups having 2 or more carbon atoms or alkanol groups having 1 or more carbon atoms, and R 1 、R 2 and R 3 It is also a preferred embodiment that at least one of the groups is an alkyl group having 4 or more carbon atoms.

[0119] In addition, the above R 1 、R 2 and R 3 are identical or different alkyl groups having 2 or more carbon atoms or alkanol groups having 2 or more carbon atoms, and R 1 、R 2 and R 3 It is also a preferred embodiment that at least one of the groups is an alkyl group having 4 or more carbon atoms.

[0120] The number of carbon atoms in the alkyl group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the alkyl group may be 5 or less.

[0121] The number of carbon atoms in the alkanol group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the alkanol group may be 5 or less.

[0122] In the general formula (A1), X is a counter ion. Examples of X include Cl, OH, Br, I, NO 3 , SO 4 , and preferably Cl or OH. In the case of a divalent anion such as SO 4 , one counter ion coordinates with two molecules of the repeating unit of the general formula (A1).

[0123] In the above general formula (A2), R 4 and R 5 The same or different ones are hydrogen atoms or organic groups, R 4 and R 5 At least one of them is an organic group having 2 or more carbon atoms.

[0124] R 4 and R 5 All of them may be organic groups. Alternatively, one may be a hydrogen atom and the other may be an organic group.

[0125] In the general formula (A2), the above R 4 and R 5 At least one of them is an organic group having 2 or more carbon atoms.

[0126] R 4 and R 5 In the formula (R), one may be an organic group having 2 or more carbon atoms, and one may be a hydrogen atom or an organic group having 1 carbon atom. 4 and R 5 Both may be organic groups having 2 or more carbon atoms.

[0127] The above R 4 and R 5 At least one of them may be an organic group having 3 or more carbon atoms, or an organic group having 4 or more carbon atoms.

[0128] In addition, the above R 4 and R 5 An organic group having 2 or more carbon atoms is also preferred.

[0129] The above R 4 and R 5 In the formula (I), the number of carbon atoms of the organic group is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less. The number of carbon atoms of the organic group may be 5 or less.

[0130] The above R 4 and R 5 The organic group in is preferably an alkyl group, an alkanol group or an alkenyl group, more preferably an alkyl group or an alkanol group, further preferably an alkyl group.

[0131] The above R 4 and R 5The same or different are alkyl or alkanol groups, the above R 4 and R 5 One of the more preferred embodiments is that at least one of the groups is an alkyl group having 2 or more carbon atoms or an alkanol group having 2 or more carbon atoms.

[0132] The number of carbon atoms in the alkyl group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the alkyl group may be 5 or less.

[0133] The number of carbon atoms in the alkanol group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the alkanol group may be 5 or less.

[0134] The anion exchange resin A is preferably a resin having a group represented by the general formula (A1) or a group represented by the general formula (A2) bonded to a resin matrix. Examples of the anion exchange resin A include resins having a group represented by the general formula (A1) or a group represented by the general formula (A2) bonded to a resin matrix composed of a styrene-based or acrylic-based polymer. The styrene-based or acrylic-based polymer serving as the resin matrix is ​​not limited; for example, a resin matrix used in known anion exchange resins can be used. From the perspective of fluorine-containing compound removal efficiency, the resin matrix of the anion exchange resin A is preferably a styrene-based resin.

[0135] The basicity of the anion exchange resin A can be variously set depending on the type of polymer backbone and / or ion exchange group.

[0136] The pore size of the anion exchange resin A is preferably From the perspective of removal efficiency, the pore diameter is preferably More preferably Above, more preferably In addition, it can be The above can also be In addition, the pore size can be The pore diameter can be calculated by measuring the specific surface area and the total pore volume using a gas adsorption method, for example.

[0137] From the perspective of removal efficiency, the total exchange capacity of the anion exchange resin A is preferably 0.1 eq / L-resin or greater. More preferably, it is 0.3 eq / L-resin or greater, further preferably 0.5 eq / L-resin or greater, and particularly preferably 0.7 eq / L-resin or greater. Furthermore, the upper limit is preferably 5.0 eq / L-resin or less, more preferably 2.0 eq / L-resin or less, and particularly preferably 1.5 eq / L-resin or less.

[0138] The water content of the anion exchange resin A is preferably 20% by mass or greater, more preferably 30 to 70% by mass, and even more preferably 35 to 65% by mass. By setting the water content of the anion exchange resin A to 30% by mass or greater, the fluorinated compounds can be effectively removed. Furthermore, the fluorinated compounds can be easily diffused into the particles of the anion exchange resin A. When the water content of the anion exchange resin A is 70% by mass or less, a decrease in the strength of the anion exchange resin A particles due to insufficient crosslinking can be suppressed.

[0139] The above-mentioned water content can be measured by the following method.

[0140] First, accurately weigh 10 mL of a standard-shaped sample using a graduated cylinder. Wrap the resin in cloth and centrifuge to remove any adhering moisture. The resin mass is then quickly measured. Next, dry the sample in a 105°C constant-temperature dryer for 4 hours, allow it to cool naturally in a desiccator for 30 minutes, and weigh the dried resin. The moisture content is calculated using the following formula.

[0141] Water content (mass %) = (mass of resin before drying (g) - mass of resin after drying (g)) / mass of resin before drying (g) × 100

[0142] The anion exchange resin A is typically spherical. The average particle size of the anion exchange resin A is preferably 0.1 to 5 mm, more preferably 0.2 to 2 mm, and particularly preferably 0.3 to 1.5 mm. If the average particle size of the anion exchange resin A falls within the above range, the anion exchange resin-packed tower is less likely to clog. The above average particle size is a value determined by sieving. Specifically, first, the anion exchange resin A is placed in a sieve shaker and sieved to determine the particle size distribution. Then, the diameter of the sieve opening corresponding to a residual classification of 50% is determined and used as the average particle size.

[0143] As the anion exchange resin A, commercially available products may be used, and examples thereof include PFA694E and A592E manufactured by Purolite Corporation.

[0144] The synthetic adsorbent is a porous resin without ion-exchange groups, and any known synthetic adsorbent can be used. Examples of ion-exchange groups include amino groups, quaternary ammonium groups, carboxylic acid groups, and sulfonic acid groups. Specific examples of synthetic adsorbents include styrene-based resins such as styrene-divinylbenzene copolymers, acrylic resins such as (meth)acrylate-ethylene glycol dimethacrylate copolymers, methacrylic resins, polyvinyl resins, and dextran resins. As commercially available synthetic adsorbents, specifically, as styrene-based resins, there can be mentioned Diaion HP10, Diaion HP20, Diaion HP21, Diaion HP40, Diaion HP50, SEPABEADS SP207, SEPABEADS SP70, SEPABEADS SP825, SEPABEADS SP850, SEPABEADS SP207 (all manufactured by Mitsubishi Chemical Corporation), Amberlite XAD1180N, Amberlite XAD2000, Amberlite XAD4, Amberlite FPX66 (all manufactured by DuPont), etc.; as acrylic resins, there can be mentioned Diaion HP2MG (manufactured by Mitsubishi Chemical Corporation), Amberlite HXAD-7HP (manufactured by DuPont), etc.

[0145] The pore size of the synthetic adsorbent is preferably From the perspective of removal efficiency, the pore diameter is preferably More preferably Above, more preferably In addition, it can be The above can also be In addition, the pore size can be The following can also be The pore diameter can be calculated by measuring the specific surface area and the total pore volume using a gas adsorption method, for example.

[0146] The specific surface area of ​​the synthetic adsorbent is preferably 300 m 2 / g or more. The specific surface area is more preferably 400m 2 / g or more, more preferably 500m 2 / g or more, more preferably 600m 2 / g or more. The upper limit of the specific surface area is not limited, for example, it can be 2000m 2 / g or less, can be 1500m 2 / g or less, or 1000m 2 The pore volume of the synthetic adsorbent is preferably 0.6 to 2.5 cm 3 / g. More preferably, it is 0.9 to 2.3 cm 3 / g, more preferably 1.1 to 2.1 cm 3 / g, particularly preferably 1.3 to 2.0 cm 3 / g. Pore volume is less than 0.6cm 3 / g, the adsorption of the above fluorinated compounds may decrease, and if it exceeds 2.5cm 3 / g, the adsorbent may be damaged. The above pore volume refers to the value measured by the nitrogen method.

[0147] To improve the removal efficiency of the fluorinated compounds, the synthetic adsorbent preferably contains water. The water content is preferably 20 to 80% by mass, more preferably 40 to 75% by mass, and particularly preferably 50 to 70% by mass. If the water content of the synthetic adsorbent is less than 20% by mass, the removal efficiency of the fluorinated compounds may decrease, while if it exceeds 80% by mass, weighing may become unstable.

[0148] Synthetic adsorbents are typically spherical. The average particle size of the synthetic adsorbent is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and particularly preferably 0.3 to 1.0 mm. If the average particle size of the synthetic adsorbent is less than 0.1 mm, separation after contact with the aqueous fluoropolymer dispersion may be difficult. If the average particle size exceeds 2.0 mm, the removal efficiency of fluorinated compounds may decrease. The average particle size of the synthetic adsorbent refers to the 50% mass value obtained by plotting the integrated mass after sieve classification.

[0149] The temperature in step A is not particularly limited and may be, for example, 0 to 50°C. From the perspective of improving removal efficiency, it is preferably 5°C or higher. It is preferably 40°C or lower, more preferably 35°C or lower, and may also be 20°C or lower.

[0150] The pressure in the above step A is not particularly limited, and may be, for example, 0.1 to 10 atmospheres, and may be carried out under normal pressure (about 1 atmosphere).

[0151] The contact time in the above step A is not particularly limited and may be 0.1 seconds to 100 hours, 1 second to 50 hours, 1 second to 10 hours, or 1 second to 1 hour.

[0152] In step A, the amount of anion exchange resin A or synthetic adsorbent relative to the aqueous fluoropolymer dispersion is not limited. For example, it can be 0.01 to 1000 g per 1000 g of the aqueous fluoropolymer dispersion. It is preferably 0.1 g or more, more preferably 1 g or more, and even more preferably 5 g or more per 1000 g of the aqueous fluoropolymer dispersion. Furthermore, it is preferably 500 g or less.

[0153] The above-mentioned step A can be the following step: after contacting the above-mentioned fluoropolymer aqueous dispersion with anion exchange resin A or synthetic adsorbent, the fluoropolymer aqueous dispersion and the anion exchange resin A or synthetic adsorbent are separated, and the fluoropolymer aqueous dispersion is recovered (the fluoropolymer aqueous dispersion is purified), and the anion exchange resin A or synthetic adsorbent is recovered at the same time.

[0154] In the production method of the present invention, the contact in the step A may be carried out in a batch manner or in a flow manner.

[0155] In addition, the above-mentioned step A can be carried out once, or can be repeated 2 or more times. From the aspect of being able to further reduce the above-mentioned fluorine-containing compound, step A is preferably carried out 2 or more times. In addition, the upper limit of the number of times is not limited, for example, it can be 10 times or less.

[0156] Conventional methods can be used to contact the aqueous fluoropolymer dispersion with the anion exchange resin A or synthetic adsorbent. For example, the method can be carried out by adding the anion exchange resin A or synthetic adsorbent to the aqueous fluoropolymer dispersion and stirring, or by a column method in which the aqueous fluoropolymer dispersion is injected into a column filled with the anion exchange resin A or synthetic adsorbent. The packed column used in the column method can be any of a mobile type, a fixed bed type, or a fluidized bed type.

[0157] When using a method in which an anion exchange resin A or a synthetic adsorbent is added to an aqueous fluoropolymer dispersion and stirred, it is preferred to include a separation step after step A for separating the anion exchange resin A or the synthetic adsorbent from the aqueous fluoropolymer dispersion after step A. The method for separating the anion exchange resin A or the synthetic adsorbent from the aqueous fluoropolymer dispersion after step A is not limited, and for example, filtration can be used.

[0158] The production method of the present invention preferably further comprises a step B of bringing the aqueous fluoropolymer dispersion into contact with an anion exchange resin B.

[0159] The anion exchange resin B may be the same as or different from the anion exchange resin A, but is preferably different from the anion exchange resin A.

[0160] The anion exchange resin B preferably has an ion exchange group (excluding the group represented by the general formula (A1) and the group represented by the general formula (A2)), for example, an amino group and / or a quaternary ammonium group. The ion exchange group is preferably the following general formula (B1):

[0161] -N + (CH3)3X -

[0162] (wherein X represents a counter ion.) or the following general formula (B2):

[0163] -N + (CH3)2(C2H4OH)X -

[0164] (wherein X represents a counter ion.) A group represented by. Examples of X in general formulas (B1) and (B2) include Cl, OH, Br, I, NO3, SO4, etc., preferably Cl or OH. It should be noted that in the case of a divalent anion such as SO4, one counter ion coordinates with two molecules of the repeating unit of general formula (A1).

[0165] The anion exchange resin B is preferably a resin having the ion exchange groups bonded to a resin matrix. Examples of the resin matrix include styrene-based or acrylic polymers. The styrene-based or acrylic polymers used as the resin matrix are not limited; for example, resin matrices used in known anion exchange resins can be used. From the perspective of fluorine-containing compound removal efficiency, the resin matrix of the anion exchange resin B is preferably a styrene-based one.

[0166] The anion exchange resin B may be weakly basic or strongly basic, and is preferably a strongly basic anion exchange resin.

[0167] The basicity of the anion exchange resin B can be variously set depending on the type of polymer skeleton and / or ion exchange group.

[0168] The pore size of the anion exchange resin B is preferably From the perspective of removal efficiency, the pore diameter is preferably More preferably Above, more preferably In addition, it can be The above can also be In addition, the pore size can be The pore diameter can be calculated by measuring the specific surface area and the total pore volume using a gas adsorption method, for example.

[0169] From the perspective of removal efficiency, the total exchange capacity of the anion exchange resin B is preferably 0.1 eq / L-resin or greater. It is more preferably 0.3 eq / L-resin or greater, further preferably 0.5 eq / L-resin or greater, and particularly preferably 0.7 eq / L-resin or greater. The greater the total exchange capacity, the better. For example, the upper limit is preferably 5.0 eq / L-resin, more preferably 2.0 eq / L-resin or less, and particularly preferably 1.5 eq / L-resin or less.

[0170] The water content of the anion exchange resin B is preferably 20% by mass or greater, more preferably 30 to 70% by mass, and even more preferably 35 to 65% by mass. By setting the water content of the anion exchange resin B to 30% by mass or greater, the fluorinated compounds can be effectively removed. Furthermore, the fluorinated compounds can be easily diffused into the particles of the anion exchange resin B. When the water content of the anion exchange resin B is 70% by mass or less, a decrease in the strength of the anion exchange resin B particles due to insufficient crosslinking can be suppressed.

[0171] The water content can be measured by the same method as that of the anion exchange resin A.

[0172] The anion exchange resin B is typically spherical. The average particle size of the anion exchange resin B is preferably 0.1 to 5 mm, more preferably 0.2 to 2 mm, and particularly preferably 0.3 to 1.5 mm. If the average particle size of the anion exchange resin B is within the above range, the anion exchange resin-packed tower is less likely to clog. The above average particle size is a value determined by sieving. Specifically, first, the anion exchange resin B is placed in a vibrating sieve and sieved to determine the particle size distribution. Then, the diameter of the sieve opening corresponding to a residual classification of 50% is determined and used as the average particle size.

[0173] As the anion exchange resin B, commercially available products may be used, for example, Diaion (trademark) SA series manufactured by Mitsubishi Chemical Corporation, A400 and A300 manufactured by Purolite Corporation, Amberlite (trademark) series manufactured by DuPont, and Amberjet (trademark) series such as IRA4002OH.

[0174] The step B may be performed before or after the step A. However, performing the step B before the step A is preferred because the removal efficiency of the fluorine-containing compound is improved.

[0175] The production method of the present invention preferably comprises step B of contacting an aqueous fluoropolymer dispersion obtained using a hydrocarbon surfactant with an anion exchange resin B, and step A of contacting the aqueous fluoropolymer dispersion obtained after step B with an anion exchange resin A or a synthetic adsorbent.

[0176] The temperature in step B is not limited and may be, for example, 0 to 50°C. From the perspective of improving removal efficiency, it is preferably 5°C or higher. It is preferably 40°C or lower, more preferably 35°C or lower, and may also be 20°C or lower.

[0177] The pressure in the above step B is not particularly limited, and may be, for example, 0.1 to 10 atmospheres, and may be carried out under normal pressure (about 1 atmosphere).

[0178] The contact time in the above step B is not particularly limited and may be 0.1 seconds to 100 hours, 1 second to 50 hours, 1 second to 10 hours, or 1 second to 1 hour.

[0179] The contact in the step B may be performed batchwise or in a flow-type manner. The step B may be performed once or repeated two or more times.

[0180] In step B, the amount of anion exchange resin B relative to the aqueous fluoropolymer dispersion is not limited. For example, it can be 0.01 to 1000 g per 1000 g of the aqueous fluoropolymer dispersion. It is preferably 0.1 g or more, more preferably 1 g or more, and even more preferably 5 g or more per 1000 g of the aqueous fluoropolymer dispersion. Furthermore, it is preferably 500 g or less.

[0181] Conventionally used methods can be used to contact the aqueous fluoropolymer dispersion with the anion exchange resin B, and the method described in the above step A can be appropriately used. For example, a method of adding the anion exchange resin B to the aqueous fluoropolymer dispersion and stirring the mixture can be mentioned.

[0182] When using a method in which anion exchange resin B is added to an aqueous fluoropolymer dispersion and stirred, it is preferred that in step B, after the aqueous fluoropolymer dispersion and anion exchange resin B are brought into contact, the anion exchange resin B be separated from the aqueous fluoropolymer dispersion after step B. The method for separating anion exchange resin B from the aqueous fluoropolymer dispersion is not limited; for example, filtration may be used. Step B may be a step in which the anion exchange resin B is recovered after the aqueous fluoropolymer dispersion and anion exchange resin B are brought into contact.

[0183] The anion exchange resins A and B and the synthetic adsorbent used in steps A and B can also be reused by eluting the adsorbed fluorine-containing compound with an alkaline solution containing water and an organic solvent. As the alkaline, alkali metal hydroxides such as NaOH and KOH and NH4OH can be used. In addition, the eluted fluorine-containing compound can be recovered.

[0184] The manufacturing method of the present invention preferably includes a step of adding a nonionic surfactant to the fluoropolymer aqueous dispersion before step A. The fluoropolymer aqueous dispersion obtained using a hydrocarbon surfactant usually contains a hydrocarbon surfactant, but the amount of the hydrocarbon surfactant will be reduced due to step A, and the stability of the aqueous dispersion may be reduced. By adding a nonionic surfactant before step A, the stability of the fluoropolymer aqueous dispersion after step A can be improved. The amount of the nonionic surfactant added is not particularly limited, as long as it is an amount that can maintain the stability of the fluoropolymer aqueous dispersion. For example, it is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to the fluoropolymer contained in the fluoropolymer aqueous dispersion.

[0185] When step B is performed before step A, it is preferred that step B include a step of adding a nonionic surfactant to the aqueous fluoropolymer dispersion.

[0186] In the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, examples of the nonionic surfactant include those represented by the following general formula (i):

[0187] R 6 -OA 1 -H(i)

[0188] (Where R 6 is a linear or branched primary or secondary alkyl group having 8 to 18 carbon atoms, 1 is a polyoxyalkylene chain. )

[0189] R 6 The number of carbon atoms in R is preferably 10 to 16, more preferably 12 to 16. 6 When the number of carbon atoms of R is 18 or less, the aqueous dispersion liquid can easily obtain good dispersion stability. 6 When the number of carbon atoms exceeds 18, the flow temperature is high and thus it is difficult to handle. 6 When the number of carbon atoms is less than 8, the surface tension of the aqueous dispersion increases, and the permeability and wettability are likely to decrease.

[0190] The polyoxyalkylene chain can be composed of ethylene oxide and propylene oxide. The polyoxyalkylene chain is preferably composed of an average repeating number of 5 to 20 ethylene oxide units and an average repeating number of 0 to 2 propylene oxide units, and is a hydrophilic group. The number of ethylene oxide units can include either a conventionally provided broad or narrow unimodal distribution, or a broader or bimodal distribution obtained by blending. When the average repeating number of propylene oxide units is greater than 0, the ethylene oxide and propylene oxide groups in the polyoxyalkylene chain can be arranged in blocks or randomly.

[0191] As the polyoxyalkylene chain, a polyoxyalkylene chain composed of an average repeating number of 7 to 12 ethylene oxide and an average repeating number of 0 to 2 propylene oxide is preferred from the viewpoint of viscosity and stability of the aqueous dispersion. 1 When the average number of propylene oxide groups is 0.5 to 1.5, low foaming properties are good, which is preferred.

[0192] More preferably, R 6 (R')(R")HC-, wherein R' and R" are the same or different linear, branched or cyclic alkyl groups, and the total number of carbon atoms is at least 5, preferably 7 to 17. Preferably, at least one of R' or R" is a branched or cyclic hydrocarbon group.

[0193] Specific examples of the compound (polyoxyethylene alkyl ether) represented by the general formula (i) include C 13 H 27 -O-(C2H4O) 10 -H, C 13 H 27 -O-(C2H4O)8-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 compound represented by the general formula (i) include Genapol X080 (product name, manufactured by Clariant), NOIGEN TDS series (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) exemplified by NOIGEN TDS-80 (trade name), LEOCOL TD series (manufactured by Lion Corporation) exemplified by LEOCOL TD-90 (trade name), LIONOL (registered trademark) TD series (manufactured by Lion Corporation), T-Det A series (manufactured by Harcros Chemicals) exemplified by T-Det A138 (trade name), and Tergitol (registered trademark) 15-S series (manufactured by The Dow Chemical Company).

[0194] The nonionic surfactant is preferably a 2,6,8-trimethyl-4-nonanol ethoxylate having an average of about 4 to about 18 ethylene oxide units, a 2,6,8-trimethyl-4-nonanol ethoxylate 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 as, for example, TERGITOL TMN-6, TERGITOL TMN-10, and TERGITOL TMN-100X (all product names, manufactured by The Dow Chemical Company).

[0195] In addition, the hydrophobic group of the nonionic surfactant may be any of an alkylphenol group, a linear alkyl group, and a branched alkyl group.

[0196] For example, examples of the polyoxyethylene ether alkylphenyl ether nonionic compound include the following general formula (ii):

[0197] R 7 -C6H4-OA 2 -H(ii)

[0198] (Where R 7 is a linear or branched primary or secondary alkyl group having 4 to 12 carbon atoms, 2 ) is a compound represented by a polyoxyalkylene chain. Specific examples of the polyoxyethylene ether alkylphenyl ether nonionic compound include TRITON (registered trademark) X-100 (trade name, manufactured by The Dow Chemical Company).

[0199] Examples of the nonionic surfactant include polyol compounds, and specifically, polyol compounds described in International Publication No. 2011 / 014715.

[0200] Typical examples of polyol compounds include compounds having one or more sugar units as polyol units. The sugar units may be modified to contain at least one long chain. Preferred polyol compounds containing at least one long chain portion include, for example, alkyl glucosides, modified alkyl glucosides, sugar esters, and combinations thereof. Examples of sugars include, but are not limited to, monosaccharides, oligosaccharides, and sorbitan. Examples of monosaccharides include, but are not limited to, pentose and hexose. Typical examples of monosaccharides include ribose, glucose, galactose, mannose, fructose, arabinose, and xylose. Examples of oligosaccharides include oligomers of 2 to 10 identical or different monosaccharides. Examples of oligosaccharides include, but are not limited to, sucrose, maltose, lactose, raffinose, and isomaltose.

[0201] Typically, sugars suitable for use as polyol compounds include five-membered ring compounds containing four carbon atoms and one heteroatom (typically oxygen or sulfur, preferably an oxygen atom), or six-membered ring compounds containing five carbon atoms and one of the aforementioned heteroatoms, preferably an oxygen atom. These sugars further contain at least two or at least three hydroxyl groups (-OH groups) bonded to carbon ring atoms. Typically, the sugars are modified by replacing one or more hydrogen atoms of the hydroxyl (and / or hydroxyalkyl) groups bonded to carbon ring atoms with long-chain residues, thereby forming ether or ester bonds between the long-chain residues and the sugar moiety.

[0202] The sugar polyol may contain one sugar unit or two or more sugar units. One sugar unit or two or more sugar units may be modified in the long chain portion. Specific examples of sugar polyol compounds include glucosides, sugar esters, sorbitan esters, and mixtures and combinations thereof.

[0203] The preferred class of polyol compounds is alkyl glucosides or modified alkyl glucosides. These classes of surfactants contain at least one glucose moiety.

[0204] Can cite

[0205] [Chemistry 1]

[0206]

[0207] (wherein, x represents 0, 1, 2, 3, 4 or 5, R 1 and R 2 independently represents H or a long chain unit containing at least 6 carbon atoms, wherein R 1 and R 2 At least one of which is not H) is a compound represented by R 1 and R 2 Typical examples include aliphatic alcohol residues. Examples of aliphatic alcohols include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, cetyl alcohol, heptadecanol, stearyl alcohol (stearyl alcohol), eicosanoic acid, and combinations thereof.

[0208] The above formula shows a specific example of an alkyl polyglucoside of glucose showing the pyranose form, but it will be appreciated that other sugars or sugars in different mirror isomer or diastereoisomer forms of the same sugar may also be used.

[0209] Alkyl glucosides can be obtained, for example, by the acid-catalyzed reaction of glucose, starch, or n-butyl glucoside with an aliphatic alcohol. In typical examples, a mixture of various alkyl glucosides can be obtained (Alkylpolygylcoside, Rompp, Lexikon Chemie, Version 2.0, Stuttgart / New York, Georg Thieme Verlag, 1999). Examples of aliphatic alcohols include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, cetyl alcohol, heptadecanol, stearyl alcohol (stearyl alcohol), eicosanoic acid, and combinations thereof. Alkyl glucosides are commercially available from Cognis GmbH, Dusseldorf, Germany, under the trade names GLUCOPON or DISPONIL.

[0210] Examples of other nonionic surfactants include bifunctional block copolymers supplied by BASF as the Pluronic (registered trademark) R series, tridecanol alkoxylates supplied by BASF as the Iconol (registered trademark) TDA series, and hydrocarbon-containing silicone surfactants.

[0211] As the nonionic surfactant, a nonionic surfactant containing no aromatic part is preferred.

[0212] The production method of the present invention preferably includes, after step A, a step of concentrating the aqueous fluoropolymer dispersion after step A.

[0213] Examples of the above-mentioned concentration method include phase separation concentration, ion exchange method, membrane concentration, etc. The above-mentioned phase separation concentration, ion exchange method, and membrane concentration can be carried out using conventionally known treatment conditions without particular limitation, and can be carried out using the methods described in International Publication No. 2004 / 050719, Japanese Unexamined Patent Application Publication No. 2002-532583, and Japanese Patent Application Laid-Open No. 55-120630.

[0214] Phase separation concentration is preferred as the above-mentioned concentration method. Phase separation concentration is usually performed by adding a nonionic surfactant. The production method of the present invention preferably further includes a step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion after step A to perform phase separation concentration.

[0215] The phase separation and concentration is performed, for example, by heating the aqueous dispersion to which the nonionic surfactant is added to separate the dispersion into a fluoropolymer-free phase (supernatant phase) and a fluoropolymer-containing phase (concentrated phase), removing the fluoropolymer-free phase, and recovering the fluoropolymer-containing phase.

[0216] The phase separation concentration can be performed by allowing the mixture to stand at a temperature 10° C. or higher than the cloud point of the nonionic surfactant used. Alternatively, the phase separation concentration can be performed by allowing the mixture to stand at a temperature 10° C. or lower than the cloud point.

[0217] As the nonionic surfactant, those described in the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion, which is performed before the above step B, can be used.

[0218] As the nonionic surfactant, a nonionic surfactant containing no aromatic part is preferred.

[0219] During the phase separation and concentration, the amount of the nonionic surfactant added is not limited, but may be added in an amount preferably not more than 50% by mass, more preferably not more than 20% by mass, and even more preferably not more than 15% by mass relative to 100% by mass of the fluoropolymer. The amount added may be within the above range; for example, an amount of 0.1% by mass or more relative to 100% by mass of the fluoropolymer may be added.

[0220] In the production method of the present invention, the above-mentioned step C is preferably performed two or more times. More preferably, step C is performed three or more times. The upper limit of the number of times is not limited, and for example, it can be 10 times or less.

[0221] When step C is performed two or more times, the phase separation and concentration in the first step C is preferably performed by heating at a temperature 5°C or higher below the cloud point of the nonionic surfactant and then allowing the mixture to stand to separate into a supernatant phase and a concentrated phase. The heating temperature is more preferably 3°C or higher below the cloud point, further preferably above the cloud point, and particularly preferably above the cloud point.

[0222] In the second or subsequent phase separation and concentration steps C, the phase separation is preferably performed by heating at a temperature 5°C or higher below the cloud point of the nonionic surfactant and then allowing the phase to separate into a supernatant phase and a concentrated phase. The heating temperature is more preferably 3°C or higher below the cloud point, and heating to the cloud point is particularly preferred.

[0223] The production method of the present invention can effectively remove the following fluorinated compounds from a fluoropolymer aqueous dispersion, thereby obtaining a purified fluoropolymer aqueous dispersion having a reduced amount of the following fluorinated compounds. The fluoropolymer aqueous dispersion subjected to treatment preferably contains a fluorinated compound represented by the following general formula (1) or (2).

[0224] General formula (1): (H-(CF2) m -COO) p M 1

[0225] (where m is 3 to 19, M1 H, metal atoms, NR 5 4(R 5 (may be the same or different and be H or an organic group having 1 to 10 carbon atoms), an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. p is 1 or 2.)

[0226] General formula (2): (H-(CF2) n -SO3) q M 2

[0227] (where n is 4 to 20. 2 H, metal atoms, NR 5 4(R 5 Same as above), an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent. q is 1 or 2.

[0228] Examples of the metal atom include monovalent and divalent metal atoms, and examples thereof include alkali metals (Group 1) and alkaline earth metals (Group 2). Specific examples thereof include Na, K, and Li.

[0229] As the above R 5 , 4 R 5 They may be the same or different. 5 , can be H or an organic group having 1 to 10 carbon atoms, can be H or an organic group having 1 to 4 carbon atoms. In one embodiment, it is an alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 4 carbon atoms. All R 5 The above provisions may apply.

[0230] In the general formula (1), m may be 5 to 11.

[0231] In the general formula (2), n may be 6 to 12.

[0232] The above-mentioned aqueous fluoropolymer dispersion may contain the fluorine-containing compound represented by general formula (1) but not the fluorine-containing compound represented by general formula (2), may not contain the fluorine-containing compound represented by general formula (1) but contain the fluorine-containing compound represented by general formula (2), or may contain both the fluorine-containing compound represented by general formula (1) and the fluorine-containing compound represented by general formula (2).

[0233] In addition, it may contain two or more fluorine-containing compounds contained in the general formula (1), it may contain two or more fluorine-containing compounds contained in the general formula (2), or it may contain two or more compounds contained in the general formula (1) and two or more fluorine-containing compounds contained in the general formula (2), without limitation.

[0234] For example, there can be mentioned an embodiment comprising a fluorine-containing compound wherein m is 6 and a fluorine-containing compound wherein m is 12 of the general formula (1), and an embodiment comprising a fluorine-containing compound wherein n is 6 and a fluorine-containing compound wherein n is 12 of the general formula (2). In addition, it is sufficient that at least one of the fluorine-containing compound represented by the general formula (1) and the compound represented by the general formula (2) is contained, and two or more, three or more, or four or more may be contained.

[0235] The fluorine-containing compounds included in the general formula (1) may include fluorine-containing compounds in which m is 3, 5, 7, 9, 11, 13, 15, 17 and 19 but not include fluorine-containing compounds in which m is 4, 6, 8, 10, 12, 14, 16 and 18; may include fluorine-containing compounds in which m is 4, 6, 8, 10, 12, 14, 16, 18 and 20 but not include fluorine-containing compounds in which m is 3, 5, 7, 9, 11, 13, 15, 17 and 19; or may include all fluorine-containing compounds in which m is 3 to 19.

[0236] In addition, the fluorine-containing compounds included in the general formula (2) may be a form including fluorine-containing compounds in which n is 5, 7, 9, 11, 13, 15, 17 and 19 but not including fluorine-containing compounds in which n is 4, 6, 8, 10, 12, 14, 16, 18 and 20, a form including fluorine-containing compounds in which n is 4, 6, 8, 10, 12, 14, 16, 18 and 20 but not including fluorine-containing compounds in which n is 5, 7, 9, 11, 13, 15, 17 and 19, or a form including all fluorine-containing compounds in which n is 4 to 20.

[0237] In the production method of the present invention, the concentration of the fluorinated compound represented by the general formula (1) or (2) in the aqueous fluoropolymer dispersion to be treated is not particularly limited, and an aqueous fluoropolymer dispersion having any concentration can be treated.

[0238] In the aqueous fluoropolymer dispersion to be treated, the total content of the compounds represented by the general formula (1) and (2) may exceed 1 ppm relative to the fluoropolymer, and may be 2 ppm or more, 5 ppm or more, 10 ppm or more, or 50 ppm or more. When the concentration of the fluorinated compound represented by the general formula (1) or (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, higher removal efficiency can be achieved.

[0239] In addition, in the aqueous fluoropolymer dispersion to be treated, the total content of the fluorinated compounds represented by the general formulas (1) and (2) relative to the fluoropolymer can be 30,000 ppm or less, 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less. By making the total amount of the above-mentioned fluorinated compounds in the aqueous fluoropolymer dispersion within the above-mentioned range, the removal efficiency can be further improved. It should be noted that the above-mentioned total content is the sum of the content of all fluorinated compounds contained in the general formula (1) and the content of all fluorinated compounds contained in the general formula (2).

[0240] As the above-mentioned aqueous fluoropolymer dispersion, a fluoropolymer aqueous dispersion obtained by polymerization of a fluoropolymer may be used directly, or a fluoropolymer aqueous dispersion produced by polymerization of a fluoropolymer may be diluted or concentrated so that the total amount of the fluorine-containing compounds represented by general formulae (1) and (2) falls within the above-mentioned range.

[0241] In addition, in this specification, ppm is a value calculated based on mass conversion unless otherwise stated.

[0242] The amount of at least one of the fluorine-containing compounds wherein m in the general formula (1) is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, more than 1 ppm, 5 ppm or more, or 10 ppm or more, respectively, relative to the fluoropolymer.

[0243] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0244] In addition, the amount of at least one fluorine-containing compound wherein m in the general formula (1) is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less, relative to the fluoropolymer. By setting the amount of the fluorine-containing compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0245] The amount of the fluorine-containing compound wherein m is 3 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0246] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0247] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 3 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0248] The amount of the fluorine-containing compound wherein m is 4 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0249] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0250] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 4 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0251] The amount of the fluorine-containing compound wherein m is 5 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0252] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0253] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 5 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0254] The amount of the fluorine-containing compound wherein m is 6 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0255] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0256] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 6 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0257] The amount of the fluorine-containing compound wherein m is 7 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0258] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0259] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 7 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0260] The amount of the fluorine-containing compound wherein m is 8 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0261] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0262] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 8 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0263] The amount of the fluorine-containing compound wherein m is 9 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0264] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0265] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 9 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0266] The amount of the fluorine-containing compound wherein m is 10 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0267] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0268] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 10 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0269] The amount of the fluorine-containing compound wherein m is 11 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0270] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0271] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 11 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0272] The amount of the fluorine-containing compound wherein m is 12 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0273] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0274] In addition, the amount of the fluorinated compound wherein m in the general formula (1) is 12 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0275] The amount of the fluorine-containing compound wherein m is 13 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0276] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0277] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 13 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0278] The amount of the fluorine-containing compound wherein m is 14 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0279] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0280] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 14 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0281] The amount of the fluorine-containing compound wherein m is 15 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0282] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0283] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 15 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0284] The amount of the fluorine-containing compound wherein m is 16 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0285] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0286] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 16 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0287] The amount of the fluorine-containing compound wherein m is 17 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0288] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0289] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 17 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0290] The amount of the fluorine-containing compound wherein m is 18 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0291] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0292] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 18 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0293] The amount of the fluorine-containing compound wherein m is 19 in the general formula (1) may be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer.

[0294] When the concentration of the fluorine-containing compound represented by the general formula (1) in the aqueous fluoropolymer dispersion is equal to or higher than a certain concentration as described above, higher removal efficiency can be achieved.

[0295] In addition, the amount of the fluorinated compound in which m in the general formula (1) is 19 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0296] The amount of at least one of the fluorinated compounds wherein n in the general formula (2) is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, higher removal efficiency can be achieved.

[0297] In addition, the amount of at least one of the fluorinated compounds wherein n in the general formula (2) is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 may be 10,000 ppm or less, 5,000 ppm or less, further 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less, relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0298] The amount of the fluorinated compound represented by the general formula (2) in which n is 4 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0299] In addition, the amount of the fluorinated compound wherein n is 4 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0300] The amount of the fluorinated compound represented by the general formula (2) in which n is 5 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0301] In addition, the amount of the fluorinated compound wherein n is 5 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0302] The amount of the fluorinated compound represented by the general formula (2) in which n is 6 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0303] In addition, the amount of the fluorinated compound wherein n is 6 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0304] The amount of the fluorinated compound represented by the general formula (2) in which n is 7 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0305] In addition, the amount of the fluorinated compound wherein n is 7 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0306] The amount of the fluorinated compound represented by the general formula (2) in which n is 8 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0307] In addition, the amount of the fluorinated compound wherein n is 8 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0308] The amount of the fluorinated compound represented by the general formula (2) in which n is 9 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0309] In addition, the amount of the fluorinated compound wherein n is 9 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0310] The amount of the fluorinated compound represented by the general formula (2) in which n is 10 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0311] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 10 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0312] The amount of the fluorinated compound represented by the general formula (2) in which n is 11 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0313] In addition, the amount of the fluorinated compound wherein n is 11 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0314] The amount of the fluorinated compound represented by the general formula (2) in which n is 12 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0315] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 12 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0316] The amount of the fluorinated compound represented by the general formula (2) in which n is 13 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0317] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 13 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0318] The amount of the fluorinated compound represented by the general formula (2) in which n is 14 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, higher removal efficiency can be achieved.

[0319] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 14 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0320] The amount of the fluorinated compound represented by the general formula (2) in which n is 15 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0321] In addition, the amount of the fluorinated compound wherein n is 15 in the general formula (2) may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0322] The amount of the fluorinated compound represented by the general formula (2) in which n is 16 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0323] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 16 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0324] The amount of the fluorinated compound represented by the general formula (2) in which n is 17 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0325] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 17 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0326] The amount of the fluorinated compound represented by the general formula (2) in which n is 18 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0327] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 18 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0328] The amount of the fluorinated compound represented by the general formula (2) in which n is 19 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0329] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 19 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By setting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion within the above range, the removal efficiency can be further improved.

[0330] The amount of the fluorinated compound represented by the general formula (2) in which n is 20 can be 0.01 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 5 ppm or more, or 10 ppm or more relative to the fluoropolymer. When the concentration of the fluorinated compound represented by the general formula (2) in the aqueous fluoropolymer dispersion is above a certain concentration as described above, a higher removal efficiency can be achieved.

[0331] In addition, the amount of the fluorinated compound wherein n in the general formula (2) is 20 may be 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 200 ppm or less relative to the fluoropolymer. By adjusting the amount of the fluorinated compound in the aqueous fluoropolymer dispersion to the above range, the removal efficiency can be further improved.

[0332] The aqueous fluoropolymer dispersion preferably contains at least a fluorinated compound represented by the general formula (1) wherein m is 7 or greater, or a fluorinated compound represented by the general formula (2) wherein n is 8 or greater.

[0333] The above-mentioned aqueous fluoropolymer dispersion more preferably contains a fluorine-containing compound wherein m of the general formula (1) is 9 or greater or a fluorine-containing compound wherein n of the general formula (2) is 10 or greater, and further preferably contains a fluorine-containing compound wherein m of the general formula (1) is 11 or greater or a fluorine-containing compound wherein n of the general formula (2) is 12 or greater.

[0334] The aqueous fluoropolymer dispersion preferably contains a compound represented by the general formula (1). The production method of the present invention is particularly effective when the compound represented by the general formula (1) is contained. This is particularly effective when the aqueous fluoropolymer dispersion contains a fluorinated compound in which m in the general formula (1) is 7 or greater, more preferably a fluorinated compound in which m is 9 or greater, and even more preferably a fluorinated compound in which m is 11 or greater.

[0335] In the aqueous fluoropolymer dispersion, the concentration of the fluoropolymer in the aqueous fluoropolymer dispersion is 10 to 90% by mass. The preferred lower limit of the concentration of the fluoropolymer is 15% by mass, the more preferred lower limit is 20% by mass, the preferred upper limit is 80% by mass, and the more preferred upper limit is 70% by mass.

[0336] The fluoropolymer aqueous dispersion generally comprises an aqueous medium such as water. In this specification, the term "aqueous medium" refers to water and a mixed medium comprising water and a water-soluble organic solvent (e.g., alcohols such as methanol, ethanol, and propanol, esters such as methyl acetate, ketones such as acetone, and ethers such as dimethyl ether).

[0337] The pH of the fluoropolymer aqueous dispersion may be, for example, 1.5 to 13.5, or 2 to 13, without particular limitation. For example, the pH of the fluoropolymer aqueous dispersion in steps A and B may be 2 to 12, or 2 to 11.

[0338] As a method for adjusting the pH of the aqueous fluoropolymer dispersion, a method of adjusting the pH by adding an acid or a base before step A or step B can be mentioned.

[0339] For example, when step B and step A are performed sequentially, the pH of the aqueous fluoropolymer dispersion in step B may be acidic, and the aqueous fluoropolymer dispersion supplied to step A may be alkaline.

[0340] The aqueous fluoropolymer dispersion containing the fluorinated compound represented by the above-mentioned general formula (1) or (2) can be obtained by polymerization using a hydrocarbon-based surfactant.

[0341] The fluoropolymer aqueous dispersion is preferably obtained using a hydrocarbon surfactant. More specifically, the fluoropolymer aqueous dispersion is preferably obtained by polymerizing a fluoromonomer in an aqueous medium in the presence of a hydrocarbon surfactant.

[0342] The production method of the present invention preferably further comprises a step of polymerizing a fluoromonomer in an aqueous medium in the presence of a hydrocarbon-based surfactant to obtain an aqueous fluoropolymer dispersion.

[0343] As the fluorine monomer, a fluorine monomer having at least one double bond is preferred.

[0344] The fluorinated monomer is preferably selected from tetrafluoroethylene [TFE], hexafluoropropylene [HFP], chlorotrifluoroethylene [CTFE], vinyl fluoride, vinylidene fluoride [VDF], trifluoroethylene, fluoroalkyl vinyl ether, fluoroalkyl ethylene, fluoroalkyl allyl ether, trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, the general formula (100): CHX 101 =CX 102 Rf 101 (Where X 101 and X 102 One of them is H and the other is F, Rf 101 At least one member selected from the group consisting of a fluorinated monomer represented by a linear or branched fluoroalkyl group having 1 to 12 carbon atoms, a fluorinated vinyl heterocyclic compound, and a monomer providing a crosslinking site.

[0345] As the fluoroalkyl vinyl ether, for example, preferably selected from

[0346] General formula (110): CF2=CF-ORf 111

[0347] (Where Rf 111 represents a perfluorinated organic group. ) represents a fluorinated monomer,

[0348] General formula (120): CF2=CF-OCH2-Rf 121

[0349] (Where Rf 121 is a fluorinated monomer represented by a perfluoroalkyl group having 1 to 5 carbon atoms,

[0350] General formula (130): CF2=CFOCF2ORf 131

[0351] (Where Rf 131 represents a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, or a linear or branched perfluorooxyalkyl group having 2 to 6 carbon atoms containing 1 to 3 oxygen atoms. ) Fluorine monomer represented by

[0352] General formula (140): CF2=CFO(CF2CF(Y 141 )O) m (CF2) n F

[0353] (where Y 141 represents a fluorine atom or a trifluoromethyl group. m is an integer from 1 to 4. n is an integer from 1 to 4.

[0354] General formula (150): CF2=CF-O-(CF2CFY 151 -O) n -(CFY 152 ) m -A 151

[0355] (where Y 151 represents a fluorine atom, a chlorine atom, a -SO2F group or a perfluoroalkyl group. The perfluoroalkyl group may contain an ethereal oxygen and a -SO2F group. n represents an integer from 0 to 3. n Y 151 Can be the same or different. 152 represents a fluorine atom, a chlorine atom or a -SO2F group. m represents an integer from 1 to 5. m Y 152 Can be the same or different. 151 Indicates -SO2X 151 、-COZ 151 or-POZ 152 Z 153 .X 151 Indicates F, Cl, Br, I, -OR 151 or -NR 152 R 153 . Z 151 、Z 152 and Z 153 Identical or different representation -NR 154 R 155 OR 156 . R 151 、R 152 、R 153 、R 154 、R 155 and R 156 The fluorine monomer represented by

[0356] At least one of the group consisting of.

[0357] In this specification, the "perfluoroorganic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. The perfluoroorganic group may have an ethereal oxygen.

[0358] Examples of the fluorine monomer represented by the general formula (110) include Rf 111A fluorinated monomer having a perfluoroalkyl group having 1 to 10 carbon atoms. The perfluoroalkyl group preferably has 1 to 5 carbon atoms.

[0359] Examples of the perfluoroorganic group in the general formula (110) include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

[0360] As the fluorine monomer represented by the general formula (110), Rf in the general formula (110) can be further exemplified. 111 A fluorinated monomer of a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, Rf 111 is the following formula:

[0361] [Chemistry 2]

[0362]

[0363] (wherein m represents 0 or an integer of 1 to 4.) The fluorine monomer of the group represented by 111 is the following formula:

[0364] [Chemistry 3]

[0365]

[0366] (wherein n represents an integer of 1 to 4.) A fluorine monomer or the like of a group represented by.

[0367] As the fluorine monomer represented by the general formula (110), preferably

[0368] General formula (160): CF2=CF-ORf 161

[0369] (Where Rf 161 represents a perfluoroalkyl group having 1 to 10 carbon atoms. ) represents a fluorine monomer. Rf 161 A perfluoroalkyl group having 1 to 5 carbon atoms is preferred.

[0370] The fluoroalkyl vinyl ether is preferably at least one selected from the group consisting of fluorinated monomers represented by general formulae (160), (130) and (140).

[0371] As the fluorine monomer represented by the general formula (160), it is preferred that at least one be selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) and perfluoro(propyl vinyl ether), and more preferably at least one be selected from the group consisting of perfluoro(methyl vinyl ether) and perfluoro(propyl vinyl ether).

[0372] The fluorine monomer represented by the general formula (130) is preferably at least one selected from the group consisting of CF2=CFOCF2OCF3, CF2=CFOCF2OCF2CF3 and CF2=CFOCF2OCF2CF2OCF3.

[0373] The fluorine monomer represented by the general formula (140) is preferably at least one selected from the group consisting of CF2=CFOCF2CF(CF3)O(CF2)3F, CF2=CFO(CF2CF(CF3)O)2(CF2)3F and CF2=CFO(CF2CF(CF3)O)2(CF2)2F.

[0374] As the fluorine monomer represented by the general formula (150), it is preferred to select at least one from the group consisting of CF2=CFOCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2SO2F, CF2=CFOCF2CF(CF2CF2SO2F)OCF2CF2SO2F and CF2=CFOCF2CF(SO2F)2.

[0375] As the fluorine monomer represented by the general formula (100), Rf is preferably 101 is a fluorine monomer having a linear fluoroalkyl group, more preferably Rf 101 It is a fluorine monomer with a straight-chain perfluoroalkyl group. 101 The number of carbon atoms is preferably 1 to 6. Examples of the fluorine monomer represented by the general formula (100) include CH2=CFCF3, CH2=CFCF2CF3, CH2=CFCF2CF2CF3, CH2=CFCF2CF2CF3, CH2=CFCF2CF2CF2H, CH2=CFCF2CF2CF2CF3, CHF=CHCF3 (E-isomer), CHF=CHCF3 (Z-isomer), etc. Among them, 2,3,3,3-tetrafluoropropylene represented by CH2=CFCF3 is preferred.

[0376] As the fluoroalkylethylene, preferably

[0377] General formula (170): CH2=CH-(CF2) n -X 171

[0378] (Where X 171 is H or F, and n is an integer from 3 to 10. The fluoroalkylethylene represented by ) is more preferably selected from CH2=CH-C4F9 and CH2=CH-C6F 13 At least one of the group consisting of.

[0379] Examples of the fluoroalkyl allyl ether include

[0380] General formula (180): CF2=CF-CF2-ORf111

[0381] (Where Rf 111 represents a perfluorinated organic group. ) represents a fluorinated monomer.

[0382] Rf of general formula (180) 111 With Rf of general formula (110) 111 Same as Rf 111 , preferably a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. The fluoroalkyl allyl ether represented by the general formula (180) is preferably 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, more preferably 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, and even more preferably CF2=CF-CF2-O-CF2CF2CF3.

[0383] Examples of the fluorinated vinyl heterocyclic compound include the general formula (230):

[0384] [Chemistry 4]

[0385]

[0386] (Where X 231 and X 232 are independently F, Cl, methoxy or fluorinated methoxy, Y 231 Formula Y 232 or Y 233 .

[0387] [Chemistry 5]

[0388] —FC==CF- (Y 232 )

[0389]

[0390] (Where Z 231 and Z 232 Each of the following is independently F or a fluorinated alkyl group having 1 to 3 carbon atoms. )) A fluorinated vinyl heterocyclic ring represented by.

[0391] As the monomer providing the cross-linking site, it is preferably selected from

[0392] General formula (180): CX 181 2=CX 182 -R f181 CHR 181 X 183

[0393] (Where X 181 and X 182 are independently hydrogen atoms, fluorine atoms or CH3, R f 181 is a fluoroalkylene, a perfluoroalkylene, a fluoro(poly)oxyalkylene or a perfluoro(poly)oxyalkylene, R 181 is a hydrogen atom or CH3, X 183 is an iodine atom or a bromine atom. ) represented by a fluorine monomer,

[0394] General formula (190): CX 191 2=CX 192 -R f 191 X 193

[0395] (Where X 191 and X 192 are independently hydrogen atoms, fluorine atoms or CH3, R f 191 is a fluoroalkylene, a perfluoroalkylene, a fluoropolyoxyalkylene or a perfluoropolyoxyalkylene, X 193 is an iodine atom or a bromine atom. ) represented by a fluorine monomer,

[0396] General formula (200): CF2=CFO(CF2CF(CF3)O) m (CF2) n -X 201

[0397] (wherein, m is an integer from 0 to 5, n is an integer from 1 to 3, and X 201 is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, a bromine atom or -CH2I. ) and

[0398] General formula (210): CH2=CFCF2O(CF(CF3)CF2O) m (CF(CF3)) n -X 211

[0399] (wherein, m is an integer from 0 to 5, n is an integer from 1 to 3, and X 211 is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, a bromine atom or -CH2OH. ) and

[0400] General formula (220): CR 221 R 222 =CR 223 -Z 221 -CR224 =CR 225 R 226

[0401] (Where R 221 、R 222 、R 223 、R 224 、R 225 and R 226 The same or different ones are hydrogen atoms or alkyl groups having 1 to 5 carbon atoms. 221 a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, an at least partially fluorinated alkylene group or oxyalkylene group having 1 to 10 carbon atoms, or

[0402] -(Q) p -CF2O-(CF2CF2O) m (CF2O) n -CF2-(Q) p -

[0403] (wherein Q is an alkylene group or an oxyalkylene group. p is 0 or 1. m / n is 0.2 to 5.) A (per)fluoropolyoxyalkylene group having a molecular weight of 500 to 10,000.) A monomer represented by

[0404] At least one of the group consisting of.

[0405] X 183 and X 193 Preferably it is an iodine atom. f 181 and R f 191 It is preferably a perfluoroalkylene group having 1 to 5 carbon atoms. 181 Preferably, it is a hydrogen atom. 201 Preferably, it is a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom or -CH2I. 211 Preferred is a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom or -CH2OH.

[0406] As the monomer providing a crosslinking site, it is preferably selected from CF2=CFOCF2CF(CF3)OCF2CF2CN, CF2=CFOCF2CF(CF3)OCF2CF2COOH, CF2=CFOCF2CF(CF3)OCF2CF2CH2I, CF2=CFOCF2CF2CH2I, CH2=CFCF2OCF(CF3)CF2OCF(CF3)CN, CH2=CFCF2OCF(CF3)CF2OCF(CF3 )COOH, CH2=CFCF2OCF(CF3)CF2OCF(CF3)CH2OH, CH2=CHCF2CF2I, CH2=CH(CF2)2CH=CH2, CH2=CH(CF2)6CH=CH2 and CF2=CFO(CF2)5CN, more preferably at least one selected from the group consisting of CF2=CFOCF2CF(CF3)OCF2CF2CN and CF2=CFOCF2CF2CH2I.

[0407] In the above polymerization, the fluorine-containing monomer and the non-fluorine-containing monomer can also be polymerized. Examples of the non-fluorine-containing monomer include hydrocarbon monomers reactive with the fluorine-containing monomer. Examples of the hydrocarbon monomer include olefins such as ethylene, propylene, butene, and isobutylene; alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, and cyclohexyl vinyl ether; vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl valerate, vinyl pivalate, vinyl hexanoate, vinyl octanoate, vinyl decanoate, vinyl neodecanoate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl benzoate, vinyl p-tert-butylbenzoate, vinyl cyclohexanecarboxylate, and vinyl monochloroacetate. vinyl esters such as vinyl ester, vinyl adipate, vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl cinnamate, vinyl undecylenate, vinyl hydroxyacetate, vinyl hydroxypropionate, vinyl hydroxybutyrate, vinyl hydroxyvalerate, vinyl hydroxyisobutyrate, and vinyl hydroxycyclohexanecarboxylate; alkyl allyl ethers such as ethyl allyl ether, propyl allyl ether, butyl allyl ether, isobutyl allyl ether, and cyclohexyl allyl ether; alkyl allyl esters such as ethyl allyl ester, propyl allyl ester, butyl allyl ester, isobutyl allyl ester, and cyclohexyl allyl ester, etc.

[0408] The non-fluorine-containing monomer may also be a hydrocarbon monomer containing a functional group (excluding monomers providing crosslinking sites). Examples of the hydrocarbon monomer containing a functional group include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyisobutyl vinyl ether, and hydroxycyclohexyl vinyl ether; non-fluorine-containing monomers having a carboxyl group such as itaconic acid, succinic acid, succinic anhydride, fumaric acid, fumaric anhydride, crotonic acid, maleic acid, maleic anhydride, and perfluorobutenoic acid; non-fluorine-containing monomers having a glycidyl group such as glycidyl vinyl ether and glycidyl allyl ether; non-fluorine-containing monomers having an amino group such as aminoalkyl vinyl ether and aminoalkyl allyl ether; and non-fluorine-containing monomers having an amide group such as (meth)acrylamide and hydroxymethyl acrylamide.

[0409] In the above-mentioned polymerization, by polymerizing one or two or more of the above-mentioned fluorinated monomers, an aqueous dispersion containing particles of a desired fluorinated polymer (aqueous fluorinated polymer dispersion) can be obtained.

[0410] The polymerization is preferably carried out in the presence of a nonionic surfactant.

[0411] General formula (240): Rf 241 -(X 241 ) n -Y 241

[0412] (Where Rf 241 is a partially fluorinated alkyl group or a fully fluorinated alkyl group having 1 to 12 carbon atoms, n is 0 or 1, X 241 is -O-, -COO- or -OCO-, Y 241 -(CH2) p H, -(CH2) p OH or -(OR 241 ) q (OR 242 ) r OH, p is an integer from 1 to 12, q is an integer from 1 to 12, r is an integer from 0 to 12, R 241 and R 242 is an alkylene group having 2 to 4 carbon atoms. 241 With R 242 Different from each other. ) represented by the compound,

[0413] General formula (250): H(OR 251 ) u (OR 252 ) v OH

[0414] (Where R 251 and R252 is an alkylene group having 1 to 4 carbon atoms, and u and v are integers of 1 to 5. 251 With R 252 Different from each other. ) represented by the block polymer,

[0415] A nonionic polymer having a hydrophobic group consisting of a hydrocarbon group having 8 to 20 carbon atoms and a hydrophilic group consisting of a polyalkylene oxide in the molecule and

[0416] General formula (260): R 261 m -Si-(OR 262 ) 4-m

[0417] (Where R 261 is an alkyl group having 1 to 12 carbon atoms, R 262 is an alkyl group having 1 to 4 carbon atoms, and m is an integer of 1 to 3.

[0418] At least one of the group consisting of.

[0419] As a block polymer represented by general formula (250), if a specific example is given, a block polymer consisting of at least two segments selected from the group consisting of polyoxyethylene, polyoxypropylene, and polyoxybutylene can be exemplified. Among them, polyoxyethylene-polyoxypropylene block polymers and polyoxyethylene-polyoxybutylene block polymers can be exemplified, and not only AB type but also ABA type block polymers are preferably exemplified. It is further preferred to use polyoxyethylene-polyoxypropylene block polymers and polyoxypropylene-polyoxyethylene-polyoxypropylene block polymers, thereby enabling the preparation of a stable fluoropolymer dispersion at a high concentration. In addition, when the content of the polyoxyethylene segment is 10 to 50%, it is believed that the generation of flocs due to re-agglomeration is small, and therefore it is preferred. When it is further 20 to 40%, a low-viscosity fluoropolymer dispersion can be prepared, and therefore it is preferred. The molecular weight is not particularly limited as long as it is 1000 to 7000 g / mol. In particular, when it is 2500 to 6500 g / mol, a dispersion having low viscosity and excellent dispersibility can be prepared.

[0420] During the polymerization, a nucleating agent may be used. The preferred amount of the nucleating agent can be appropriately selected depending on the type of nucleating agent, and for example, the amount relative to the aqueous medium is 1000 ppm or less, more preferably 500 ppm or less, further preferably 100 ppm or less, particularly preferably 50 ppm or less, and even more preferably 10 ppm or less.

[0421] By using the above-mentioned nucleating agent, a fluoropolymer having a smaller primary particle size can be obtained compared to polymerization carried out in the absence of the above-mentioned nucleating agent.

[0422] Examples of the nucleating agent include dicarboxylic acids, perfluoropolyether (PFPE) acids or salts thereof, hydrocarbon surfactants, etc. The nucleating agent preferably does not contain an aromatic ring and is preferably an aliphatic compound.

[0423] The nucleating agent is preferably added before or simultaneously with the addition of the polymerization initiator, but may also be added during the polymerization process to adjust the particle size distribution.

[0424] The amount of the dicarboxylic acid is preferably 1000 ppm or less, more preferably 500 ppm or less, and still more preferably 100 ppm or less relative to the aqueous medium.

[0425] The perfluoropolyether (PFPE) acid or its salt may have any chain structure in which oxygen atoms in the main chain of the molecule are separated by saturated fluorinated carbon groups having 1 to 3 carbon atoms. In addition, two or more fluorinated carbon groups may be present in the molecule. A representative structure has a repeating unit represented by the following formula:

[0426] (-CFCF3-CF2-O-) n (VII)

[0427] (-CF2-CF2-CF2-O-) n (VIII)

[0428] (-CF2-CF2-O-) n -(-CF2-O-) m (IX)

[0429] (-CF2-CFCF3-O-) n -(-CF2-O-) m (X)

[0430] These structures are described by Kasai in J. Appl. Polym. R. Sci. 57, 797 (1995). As disclosed in this document, the PFPE acid or salt thereof may have a carboxylic acid group or a salt thereof at one or both termini. Furthermore, the PFPE acid or salt thereof may have a sulfonic acid group, a phosphonic acid group, or a salt thereof at one or both termini. Furthermore, the PFPE acid or salt thereof may have different groups at each terminus. For monofunctional PFPE, the other terminus of the molecule is typically perfluorinated, but may also contain a hydrogen or chlorine atom. The PFPE acid or salt thereof has at least two etheric oxygen groups, preferably at least four, and more preferably at least six. Preferably, at least one of the fluorinated carbon groups separating the etheric oxygen groups, and more preferably at least two of the fluorinated carbon groups, has two or three carbon atoms. Even more preferably, at least 50% of the fluorinated carbon groups separating the etheric oxygen groups have two or three carbon atoms. Furthermore, the PFPE acid or salt thereof preferably has a total of at least 15 carbon atoms. For example, the preferred minimum value of n or n+m in the repeating unit structure is at least 5. PFPE acids or salts thereof having two or more acid groups at one or both ends can be used in the production method of the present invention. The PFPE acid or salt thereof preferably has a number average molecular weight of less than 6000 g / mol.

[0431] The amount of hydrocarbon surfactant used as the nucleating agent is preferably less than 40ppm, more preferably less than 30ppm, and further preferably less than 20ppm relative to the aqueous medium. It is speculated that the ppm amount of the lipophilic nucleating sites present in the aqueous medium is less than the above-mentioned amount added. Therefore, the amount of the lipophilic nucleating sites is less than the above-mentioned 50ppm, 40ppm, 30ppm, and 20ppm, respectively. The lipophilic nucleating sites are believed to exist in molecular form, so even a very small amount of the hydrocarbon-containing surfactant can generate a large amount of lipophilic nucleating sites. Therefore, even if only about 1ppm of the hydrocarbon-containing surfactant is added to the aqueous medium, a beneficial effect can be obtained. The preferred lower limit is 0.01ppm, more preferably 0.1ppm.

[0432] The hydrocarbon surfactants include nonionic surfactants and cationic surfactants, including silicone surfactants such as those disclosed in US Pat. No. 7,897,682 (Brothers et al.) and US Pat. No. 7,977,438 (Brothers et al.).

[0433] As the hydrocarbon-based surfactant, a nonionic surfactant is preferred. That is, as the nucleating agent, a nonionic surfactant is preferred. The nonionic surfactant may not contain an aromatic moiety.

[0434] As the nonionic surfactant, the nonionic surfactants described in the step of adding the nonionic surfactant to the aqueous fluoropolymer dispersion performed before step B can be used.

[0435] In addition, in the above polymerization, in addition to the hydrocarbon surfactant and other compounds with surface activity used as desired, additives can be used to stabilize the compounds. Examples of the above additives include buffers, pH adjusters, stabilization aids, and dispersion stabilizers.

[0436] Preferred stabilizing agents include paraffin wax, fluorinated oils, fluorinated solvents, and silicone oils. One stabilizing agent may be used alone or in combination of two or more. Paraffin wax is more preferred. Paraffin wax may be liquid, semisolid, or solid at room temperature, but is preferably a saturated hydrocarbon with 12 or more carbon atoms. The melting point of paraffin wax is generally preferably 40-65°C, more preferably 50-65°C.

[0437] The amount of the stabilizing agent used is preferably 0.1 to 12% by mass, more preferably 0.1 to 8% by mass, based on the mass of the aqueous medium used. The stabilizing agent is preferably sufficiently hydrophobic to completely separate from the aqueous dispersion of the fluoropolymer, such as the aqueous PTFE emulsion, after emulsion polymerization of the fluoromonomer, such as TFE, without becoming a contaminating component.

[0438] The polymerization is carried out as follows: an aqueous medium, a hydrocarbon-based surfactant, a monomer, and, if necessary, other additives are placed in a polymerization reactor. The contents of the reactor are stirred while the reactor is maintained at a predetermined polymerization temperature. A predetermined amount of polymerization initiator is then added to initiate the polymerization reaction. After the polymerization reaction has begun, additional monomers, polymerization initiators, chain transfer agents, and hydrocarbon-based surfactants may be added depending on the intended purpose. Alternatively, the hydrocarbon-based surfactant may be added after the polymerization reaction has begun.

[0439] In the above polymerization, the polymerization temperature is usually 5 to 120° C. and the polymerization pressure is 0.05 to 10 MPaG. The polymerization temperature and the polymerization pressure are appropriately determined depending on the type of monomers used, the molecular weight of the target fluoropolymer, and the reaction rate.

[0440] For example, the polymerization temperature is more preferably 30° C. or higher, and even more preferably 50° C. or higher. Furthermore, it is more preferably 120° C. or lower, and even more preferably 100° C. or lower.

[0441] The polymerization pressure is more preferably 0.3 MPaG or higher, further preferably 0.5 MPaG or higher, more preferably 5.0 MPaG or lower, further preferably 3.0 MPaG or lower. In particular, from the perspective of increasing the yield of fluoropolymer, the polymerization pressure is preferably 1.0 MPaG or higher, more preferably 1.2 MPaG or higher, further preferably 1.5 MPaG or higher, and particularly preferably 2.0 MPaG or higher.

[0442] The hydrocarbon surfactant is preferably added in an amount of 0.0001 to 10% by mass relative to 100% by mass of the aqueous medium, based on a total amount added. A more preferred lower limit is 0.001% by mass, and a more preferred upper limit is 1% by mass. If the amount is less than 0.0001% by mass, the dispersing power may be insufficient, while if it exceeds 10% by mass, the effect commensurate with the amount added may not be achieved, and may instead cause a decrease in the polymerization rate or cessation of the reaction. The amount of the compound added is appropriately determined based on the type of monomer used, the molecular weight of the target fluoropolymer, and other factors.

[0443] The above-mentioned polymerization is preferably performed by polymerizing the fluorinated monomer in the substantial absence of a fluorinated surfactant.

[0444] In this specification, "in the substantial absence of a fluorinated surfactant" means that the amount of the fluorinated surfactant relative to the aqueous medium is 10 ppm or less, preferably 1 ppm or less, more preferably 100 ppb or less, further preferably 10 ppb or less, and even more preferably 1 ppb or less.

[0445] Examples of the fluorinated surfactant include anionic fluorinated surfactants and the like.

[0446] The anionic fluorinated 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.

[0447] Furthermore, the fluorine-containing surfactant may be a surfactant containing fluorine and having an anionic portion with a molecular weight of 800 or less.

[0448] It should be noted that the above-mentioned "anionic part" refers to the part other than the cation of the above-mentioned fluorinated surfactant. For example, in the F(CF2) represented by the formula (I) described later n1 In the case of COOM, it is "F(CF2) n1 COO” part.

[0449] Examples of the fluorinated surfactant include those having a LogPOW of 3.5 or less. The LogPOW is the partition coefficient between 1-octanol and water and is represented by LogP [where P represents the ratio of the fluorinated surfactant concentration in octanol to the fluorinated surfactant concentration in water when a 1:1 octanol / water mixture containing the fluorinated surfactant undergoes phase separation].

[0450] The above LogPOW is calculated as follows: On column: TOSOHODS-120T column ( HPLC was performed on standard substances with known octanol / water partition coefficients (heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid) under the following conditions: (a) HPLC was performed on standard substances with known octanol / water partition coefficients (manufactured by Tosoh Corporation), eluent: acetonitrile / 0.6% by mass HClO₄ water = 1 / 1 (vol / vol%), flow rate: 1.0 ml / min, sample volume: 300 μL, column temperature: 40°C, detection light: UV 210 nm. A calibration curve was prepared between each dissolution time and the known octanol / water partition coefficient, and LogPOW was calculated from the elution time of HPLC in the sample solution based on the calibration curve.

[0451] Specific examples of the fluorinated surfactants include U.S. Patent Application Publication No. 2007 / 0015864, U.S. Patent Application Publication No. 2007 / 0015865, U.S. Patent Application Publication No. 2007 / 0015866, U.S. Patent Application Publication No. 2007 / 0276103, U.S. Patent Application Publication No. 2007 / 0117914, U.S. Patent Application Publication No. 2007 / 142541, U.S. Patent Application Publication No. 2008 / 0015319, and U.S. Patent No. 3,250,808. 3271341, Japanese Patent Application Publication 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, and International Publication No. 2013 / 189826.

[0452] Examples of the anionic fluorinated surfactant include the following general formula (N 0 ):

[0453] X n0 -Rf n0 -Y 0 (N 0 )

[0454] (Where X n0 For H, Cl or and F. Rf n0 It is an alkylene group having 3 to 20 carbon atoms, which is chain, branched or cyclic and in which some or all of the H groups are replaced by F. The alkylene group may contain one or more ether bonds, and some of the H groups may be replaced by Cl. 0 Is an anionic group. ) represented by the compound.

[0455] Y 0 The anionic group may be -COOM, -SO2M or -SO3M, and may be -COOM or -SO3M.

[0456] M is H, metal atom, NR 7 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 7 is H or an organic group.

[0457] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), such as Na, K, and Li.

[0458] As R 7 , which can be H or C 1-10 The organic group can be H or C 1-4 The organic group can be H or C 1-4 of alkyl.

[0459] M can be H, metal atom or NR 7 4, can be H, alkali metal (Group 1), alkaline earth metal (Group 2) or NR 7 4, can be H, Na, K, Li or NH4.

[0460] The above Rf n0 More than 50% of the H atoms may be substituted by fluorine atoms.

[0461] As the above general formula (N 0 ) can be exemplified by the compound represented by

[0462] The following general formula (N 1 ):

[0463] X n0 -(CF2) m1 -Y 0 (N 1 )

[0464] (Where X n0 is H, Cl and F, m1 is an integer from 3 to 15, Y 0As defined above. ) represented by the following general formula (N 2 ):

[0465] Rf n1 -O-(CF(CF3)CF2O) m2 CFX n1 -Y 0 (N 2 )

[0466] (Where Rf n1 is a perfluoroalkyl group having 1 to 5 carbon atoms, m2 is an integer from 0 to 3, and X n1 F or CF3, Y 0 As defined above. ) represented by the following general formula (N 3 ):

[0467] Rf n2 (CH2) m3 -(Rf n3 ) q -Y 0 (N 3 )

[0468] (Where Rf n2 is a partially or completely fluorinated alkyl group having 1 to 13 carbon atoms and which may contain an ether bond, m3 is an integer of 1 to 3, Rf n3 is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, q is 0 or 1, and Y 0 As defined above. ) represented by the following general formula (N 4 ):

[0469] Rf n4 -O-(CY n1 Y n2 ) p CF2-Y 0 (N 4 )

[0470] (Where Rf n4 is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms which may contain an ether bond, n1 and Y n2 are the same or different H or F, p is 0 or 1, Y 0 As defined above. ) and the compound represented by the general formula (N 5 ):

[0471] [Chemistry 6]

[0472]

[0473] (Where X n2 、Xn3 and X n4 Rf may be the same or different and is H, F or a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms which may contain an ether bond. n5 is a linear or branched partially or completely fluorinated alkylene group having 1 to 3 carbon atoms and may contain an ether bond, L is a connecting group, Y 0 As defined above. Wherein, X n2 、X n3 、X n4 and Rf n5 The total number of carbon atoms is 18 or less. ) is a compound represented by.

[0474] As the above general formula (N 0 ), more specifically, perfluorocarboxylic acid (I) represented by the following general formula (I), ω-H perfluorocarboxylic acid (II) represented by the following general formula (II), perfluoropolyether carboxylic acid (III) represented by the following general formula (III), perfluoroalkyl alkylene carboxylic acid (IV) represented by the following general formula (IV), perfluoroalkoxy fluorocarboxylic acid (V) represented by the following general formula (V), perfluoroalkyl sulfonic acid (VI) represented by the following general formula (VI), ω-H perfluorosulfonic acid (VII) represented by the following general formula (VII), perfluoroalkyl alkylene sulfonic acid (VIII) represented by the following general formula (VIII), alkyl alkylene carboxylic acid (IX) represented by the following general formula (IX), fluorocarboxylic acid (X) represented by the following general formula (X), alkoxy fluorosulfonic acid (XI) represented by the following general formula (XI), compound (XII) represented by the following general formula (XII), compound (XIII) represented by the following general formula (XIII), etc.

[0475] The above-mentioned perfluorocarboxylic acid (I) is represented by the following general formula (I):

[0476] F(CF2) n1 COOM (I)

[0477] (where n1 is an integer from 3 to 14, M is H, metal atom, NR 7 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 7 is H or an organic group. ) represented by.

[0478] The above-mentioned ω-H perfluorocarboxylic acid (II) is represented by the following general formula (II):

[0479] H(CF2) n2 COOM (II)

[0480] (wherein n2 is an integer of 4 to 15, and M is as defined above.)

[0481] The above-mentioned perfluoropolyether carboxylic acid (III) is represented by the following general formula (III):

[0482] Rf 1 -O-(CF(CF3)CF2O) n3 CF(CF3)COOM(III)

[0483] (Where Rf 1 is a perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer of 0 to 3, and M is as defined above. )

[0484] The above-mentioned perfluoroalkyl alkylene carboxylic acid (IV) is represented by the following general formula (IV):

[0485] Rf 2 (CH2) n4 Rf 3 COOM (IV)

[0486] (Where Rf 2 is a perfluoroalkyl group with 1 to 5 carbon atoms, Rf 3 is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, n4 is an integer of 1 to 3, and M is as defined above.

[0487] The above-mentioned alkoxyfluorocarboxylic acid (V) is represented by the following general formula (V):

[0488] Rf 4 -O-CY 1 Y 2 CF2-COOM (V)

[0489] (Where Rf 4 is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms which may contain an ether bond, 1 and Y 2 are the same or different and are H or F, and M is as defined above.

[0490] The above-mentioned perfluoroalkylsulfonic acid (VI) is represented by the following general formula (VI):

[0491] F(CF2) n5 SO3M (VI)

[0492] (wherein n5 is an integer of 3 to 14, and M is as defined above.)

[0493] The above-mentioned ω-H perfluorosulfonic acid (VII) is represented by the following general formula (VII):

[0494] H(CF2) n6 SO3M (VII)

[0495] (wherein n6 is an integer of 4 to 14, and M is as defined above.)

[0496] The above-mentioned perfluoroalkyl alkylene sulfonic acid (VIII) is represented by the following general formula (VIII):

[0497] Rf 5 (CH2) n7 SO3M (VIII)

[0498] (Where 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. )

[0499] The above-mentioned alkyl alkylene carboxylic acid (IX) is represented by the following general formula (IX):

[0500] Rf 6 (CH2) n8 COOM (IX)

[0501] (Where Rf 6 It is a linear or branched partially or fully fluorinated alkyl group having 1 to 13 carbon atoms which may contain an ether bond, n8 is an integer of 1 to 3, and M is as defined above.

[0502] The above-mentioned fluorocarboxylic acid (X) is represented by the following general formula (X):

[0503] Rf 7 -O-Rf 8 -O-CF2-COOM (X)

[0504] (Where Rf 7 is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms which may contain an ether bond, Rf 8 is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and M is as defined above.

[0505] The above-mentioned alkoxy fluorosulfonic acid (XI) is represented by the following general formula (XI):

[0506] Rf 9 -O-CY 1 Y 2 CF2-SO3M (XI)

[0507] (Where Rf 9 is a linear or branched alkyl group having 1 to 12 carbon atoms, which may contain an ether bond and may contain chlorine, and is partially or completely fluorinated. 1 and Y 2are the same or different and are H or F, and M is as defined above.

[0508] The above compound (XII) is represented by the following general formula (XII):

[0509] [Chemistry 7]

[0510]

[0511] Where, X 1 、X 2 and X 3 Rf may be the same or different and is H, F and a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms and which may contain an ether bond. 10 is a perfluoroalkylene group with 1 to 3 carbon atoms, L is a connecting group, and Y 0 Is an anionic group. ) represented by the substance.

[0512] Y 0 It can be -COOM, -SO2M or -SO3M, it can be -SO3M or COOM (wherein M is as defined above).

[0513] Examples of L include a single bond and a partially or fully fluorinated alkylene group having 1 to 10 carbon atoms which may include an ether bond.

[0514] The above compound (XIII) is represented by the following general formula (XIII):

[0515] Rf 11 -O-(CF2CF(CF3)O) n9 (CF2O) n10 CF2COOM (XIII)

[0516] (Where Rf 11 is a fluorinated alkyl group containing 1 to 5 carbon atoms containing chlorine, n9 is an integer of 0 to 3, n10 is an integer of 0 to 3, and M is as defined above. ) is represented by. Examples of compound (XIII) include CF2ClO(CF2CF(CF3)O) n9 (CF2O) n10 CF2COONH4 (a mixture having an average molecular weight of 750; wherein n9 and n10 are as defined above).

[0517] As described above, examples of the anionic fluorinated surfactant include carboxylic acid surfactants and sulfonic acid surfactants.

[0518] The polymerization initiator is not particularly limited as long as it can generate free radicals within the polymerization temperature range. Known oil-soluble and / or water-soluble polymerization initiators can be used. Polymerization can also be initiated in a redox manner by combining with a reducing agent. The concentration of the polymerization initiator is appropriately determined based on the type of monomer, the molecular weight of the target fluoropolymer, and the reaction rate.

[0519] As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

[0520] The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, for example, the following peroxides may be cited as representative substances: dialkyl peroxycarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate; peroxyesters such as tert-butyl peroxyisobutyrate and tert-butyl peroxypivalate; dialkyl peroxides such as di-tert-butyl peroxide; and di(ω-hydro-dodecafluoroheptanoyl) peroxide, di(ω-hydro-tetradecafluoroheptanoyl) peroxide, di(ω-hydro-hexafluorononanoyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluorovaleranoyl) peroxide, di(perfluorohexanoyl) peroxide, di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide. di[perfluoro(or fluorochloro)acyl]peroxides such as bis(perfluorononanoyl)peroxide, bis(ω-chloro-hexafluorobutyryl)peroxide, bis(ω-chloro-decafluorohexanoyl)peroxide, bis(ω-chloro-tetrafluorooctanoyl)peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydro-dodecafluoroheptanoyl-perfluorobutyryl-peroxide, bis(dichloropentafluorobutyryl)peroxide, bis(trichlorooctafluorohexanoyl)peroxide, bis(tetrachloroundecanoyl)peroxide, bis(pentachlorotetrafluorodecanoyl)peroxide, and bis(undecachlorotriadecanoyl)peroxide; etc.

[0521] The water-soluble free radical polymerization initiator may be a known water-soluble peroxide, for example, ammonium, potassium, or sodium salts of persulfate, perchloric acid, or percarbonate, organic peroxides such as disuccinic acid peroxide and diglutaric acid peroxide, t-butyl permaleate, and t-butyl hydroperoxide. A reducing agent may also be included, and its amount may be 0.1 to 20 times that of the peroxide.

[0522] For example, when polymerization is carried out at a low temperature of 30°C or below, a redox initiator which is a combination of an oxidizing agent and a reducing agent is preferably used as a polymerization initiator. Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, and ammonium cerium nitrate. Examples of the reducing agent include bromates, diimines, and oxalic acid. Examples of the persulfate include ammonium persulfate and potassium persulfate. In order to increase the decomposition rate of the initiator, it is also preferred 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.

[0523] As the above-mentioned redox initiator, for example, potassium permanganate / oxalic acid, ammonium persulfate / bisulfite / iron sulfate (II), ammonium persulfate / sulfite / iron sulfate (II), ammonium persulfate / sulfite, ammonium persulfate / iron sulfate (II), manganese triacetate / oxalic acid, cerium ammonium nitrate / oxalic acid, bromate / sulfite, bromate / bisulfite etc., preferably potassium permanganate / oxalic acid, ammonium persulfate / sulfite / iron sulfate (II). When using a redox initiator, any one of the oxidant or the reducing agent can be put into a polymerization tank in advance, then continuously or intermittently add another and initiate polymerization. For example, when using potassium permanganate / oxalic acid, it is preferred to put oxalic acid into the polymerization tank and continuously add potassium permanganate thereto.

[0524] The amount of polymerization initiator added is not particularly limited. It can be added all at once, sequentially, or continuously in the initial stage of polymerization in an amount that does not significantly reduce the polymerization rate (e.g., a concentration of several ppm relative to water). The upper limit is a range that allows the heat of polymerization to be removed from the apparatus surface and the reaction temperature to be increased. A more preferred upper limit is a range that allows the heat of polymerization to be removed from the apparatus surface.

[0525] The aqueous medium is a liquid containing water that serves as a reaction medium for polymerization. The aqueous medium is not particularly limited as long as it contains water, and may contain water and a non-fluorinated organic solvent such as an alcohol, ether, or ketone and / or a fluorinated organic solvent having a boiling point of 40° C. or less.

[0526] During the above polymerization, a known chain transfer agent, radical scavenger, or decomposition agent may be added according to the purpose to adjust the polymerization rate and molecular weight.

[0527] Examples of the chain transfer agent include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, and dimethyl succinate; various halogenated hydrocarbons such as isopentane, methane, ethane, propane, methanol, isopropanol, acetone, various mercaptans, and carbon tetrachloride; and cyclohexane.

[0528] As a chain transfer agent, a bromine compound or an iodine compound can be used. As a polymerization method using a bromine compound or an iodine compound, for example, a method of polymerizing a fluorine monomer in an aqueous medium in the presence of a bromine compound or an iodine compound in a substantially oxygen-free state (iodine transfer polymerization method) can be cited. As a representative example of the bromine compound or iodine compound used, for example, the general formula can be cited:

[0529] R a I x Br y

[0530] (where x and y are integers from 0 to 2 and satisfy 1≤x+y≤2, R a is a saturated or unsaturated fluorocarbon group or chlorofluorocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms, R a By using a bromine compound or an iodine compound, iodine or bromine is introduced into the polymer, and functions as a crosslinking point.

[0531] Examples of the bromine compound or iodine compound include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodine-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodine-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodethane, 1,3-diiodine-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-iodoperfluoro-1-butene, 2-bromo-4-iodoperfluoro-1-butene, monoiodinated and monobrominated substitutions of benzene, diiodinated and monobrominated substitutions, and (2-iodinated and (2-bromoethyl) substitutions, etc. These compounds can be used alone or in combination with each other.

[0532] Among these, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane are preferably used in view of polymerization reactivity, crosslinking reactivity, and availability.

[0533] 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 fluorinated monomer supplied.

[0534] The chain transfer agent may be added to the reaction vessel all at once before the start of polymerization, may be added all at once after the start of polymerization, may be added in several portions during polymerization, or may be added continuously during polymerization.

[0535] As the above-mentioned free radical scavenger, a compound that does not have reinitiation ability after addition or chain transfer to a free radical in the polymerization system is used. Specifically, a compound that readily undergoes a chain transfer reaction with a primary free radical or a propagating free radical to subsequently generate a stable free radical that does not react with the monomer is used; or a compound that readily undergoes an addition reaction with a primary free radical or a propagating free radical to generate a stable free radical is used.

[0536] The activity of substances generally referred to as chain transfer agents is characterized by a chain transfer constant and a reinitiation efficiency. Among chain transfer agents, substances with a reinitiation efficiency of almost 0% are referred to as free radical scavengers.

[0537] The radical scavenger can be, for example, a compound having a chain transfer constant to the fluorinated monomer greater than the polymerization rate constant at the polymerization temperature and having a substantially 0% reinitiation efficiency. The term "substantially 0% reinitiation efficiency" means that the generated radicals stabilize the radical scavenger.

[0538] Preferred are compounds having a chain transfer constant (Cs) (=chain transfer rate constant (kc) / polymerization rate constant (kp)) to the fluoromonomer at the polymerization temperature greater than 0.1, and the chain transfer constant (Cs) of the above-mentioned compound is more preferably 0.5 or greater, further preferably 1.0 or greater, further more preferably 5.0 or greater, and particularly preferably 10 or greater.

[0539] The radical scavenger in the present invention is preferably at least one selected from the group consisting of aromatic hydroxy compounds, aromatic amines, N,N-diethylhydroxylamine, quinone compounds, terpenes, thiocyanates, and copper chloride (CuCl 2 ).

[0540] Examples of the aromatic hydroxy compound include unsubstituted phenol, polyphenol, salicylic acid, m-salicylic acid, p-salicylic acid, gallic acid, and naphthol.

[0541] Examples of the unsubstituted phenol include o-nitrophenol, m-nitrophenol, p-nitrophenol, o-aminophenol, m-aminophenol, p-aminophenol, and p-nitrosophenol. Examples of the polyhydric phenol include catechol, resorcinol, hydroquinone, pyrogallol, phloroglucinol, and resorphalol.

[0542] Examples of the aromatic amines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and benzidine.

[0543] Examples of the quinone compound include o-benzoquinone, m-benzoquinone, p-benzoquinone, 1,4-naphthoquinone, and alizarin.

[0544] Examples of the thiocyanate include ammonium thiocyanate (NH4SCN), potassium thiocyanate (KSCN), and sodium thiocyanate (NaSCN).

[0545] As the radical scavenger, aromatic hydroxy compounds are preferred, unsubstituted phenol or polyphenol is more preferred, and hydroquinone is further preferred.

[0546] From the perspective of reducing the standard specific gravity, the amount of the radical scavenger added is preferably an amount equivalent to 3 to 500% (molar basis) of the polymerization initiator concentration. A more preferred lower limit is 5% (molar basis), further preferably 8% (molar basis), further preferably 10% (molar basis), further more preferably 13% (molar basis) or 15% (molar basis), particularly preferably 20% (molar basis), particularly preferably 25% (molar basis), particularly preferably 30% (molar basis), and particularly preferably 35% (molar basis). A more preferred upper limit is 400% (molar basis), further preferably 300% (molar basis), further more preferably 200% (molar basis), and particularly preferably 100% (molar basis).

[0547] The decomposition agent of the polymerization initiator may be any compound capable of decomposing the polymerization initiator used, and is preferably at least one selected from the group consisting of sulfites, bisulfites, bromates, diimines, diimide salts, oxalic acid, oxalates, copper salts, and iron salts. Examples of the sulfite include sodium sulfite and ammonium sulfite. Examples of the copper salt include copper (II) sulfate, and examples of the iron salt include iron (II) sulfate.

[0548] The amount of the polymerization initiator decomposition agent added is within the range of 3 to 300 mass %, preferably 3 to 150 mass %, and more preferably 15 to 100 mass %, relative to the amount of the oxidant combined as the polymerization initiator (redox initiator).

[0549] From the perspective of reducing the standard specific gravity, the amount of the polymerization initiator decomposition agent added is preferably an amount equivalent to 3 to 500% (on a molar basis) of the polymerization initiator concentration. A more preferred lower limit is 5% (on a molar basis), further preferably 8% (on a molar basis), further preferably 10% (on a molar basis), further preferably 13% (on a molar basis), and further more preferably 15% (on a molar basis). A more preferred upper limit is 400% (on a molar basis), further preferably 300% (on a molar basis), further more preferably 200% (on a molar basis), and particularly further preferably 100% (on a molar basis).

[0550] In the polymerization of the fluoromonomer, a radical scavenger or a decomposing agent for the polymerization initiator is preferably added when the concentration of the fluoropolymer formed in the aqueous medium (relative to the total concentration of the aqueous medium and the fluoropolymer) is 5% by mass or more. It is more preferably 8% by mass or more, and even more preferably 10% by mass or more.

[0551] Furthermore, it is preferably added when the concentration of the fluoropolymer formed in the aqueous medium is 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0552] During the polymerization of the fluoromonomer, a radical scavenger or a decomposition agent of the polymerization initiator may be added continuously. During the polymerization of the fluoromonomer, a radical scavenger or a decomposition agent of the polymerization initiator may be added not all at once but continuously or in divided portions over time.

[0553] The production method of the present invention may include a step (I) of polymerizing the above-mentioned fluorinated monomer in an aqueous medium in the presence of a hydrocarbon-based surfactant to produce an aqueous dispersion of fluorinated polymer (A) particles, and a step (II) of polymerizing the above-mentioned fluorinated monomer into fluorinated polymer (A) particles in the aqueous dispersion of the above-mentioned fluorinated polymer (A) particles (seed polymerization).

[0554] Examples of the fluoropolymer include TFE polymers in which the monomer with the largest molar fraction in the polymer (hereinafter referred to as "most abundant monomer") is TFE, VDF polymers in which the most abundant monomer is VDF, and CTFE polymers in which the most abundant monomer is CTFE.

[0555] In addition, as the above-mentioned fluoropolymers, as (I) non-melt-processable fluororesins, tetrafluoroethylene polymers [TFE polymers (PTFE)] can be mentioned; as (II) melt-processable fluororesins, ethylene / TFE copolymers [ETFE], TFE / HFP copolymers [FEP], TFE / perfluoro(alkyl vinyl ether) copolymers [PFA, MFA, etc.], TFE / perfluoroallyl ether copolymers, TFE / VDF copolymers, and electrolyte polymer precursors can be mentioned; as (III) fluororubbers, TFE / propylene copolymers, TFE / propylene / third monomer copolymers (the above-mentioned third monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ethers, etc.), copolymers composed of TFE and fluoroalkyl vinyl ethers; HFP / ethylene copolymers, HFP / ethylene / TFE copolymers; PVDF; thermoplastic elastomers such as VDF / HFP copolymers, HFP / ethylene copolymers, and VDF / TFE / HFP copolymers; and fluorinated segmented polymers described in Japanese Patent Publication No. 61-49327 can be mentioned.

[0556] The TFE polymer may preferably be a TFE homopolymer, or may be a copolymer composed of (1) TFE, (2) one or more fluorinated monomers other than TFE having 2 to 8 carbon atoms, particularly VDF, HFP, or CTFE, and (3) other monomers. Examples of the (3) other monomers include fluoro(alkyl vinyl ethers) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; fluoro-1,3-dioxole; perfluoroalkylethylene; and ω-hydroperfluoroolefin.

[0557] Alternatively, the TFE polymer may be a copolymer of TFE and one or more non-fluorinated monomers. Examples of such non-fluorinated monomers include olefins such as ethylene and propylene; vinyl esters; and vinyl ethers. Alternatively, the TFE polymer may be a copolymer of TFE with one or more fluorinated monomers having 2 to 8 carbon atoms and one or more non-fluorinated monomers.

[0558] The VDF polymer may preferably be a VDF homopolymer [PVDF], or may be a copolymer composed of (1) VDF, (2) one or more fluoroolefins other than VDF having 2 to 8 carbon atoms, particularly TFE, HFP or CTFE, and (3) a perfluoro(alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms.

[0559] The CTFE polymer may preferably be a CTFE homopolymer, or may be a copolymer composed of (1) CTFE, (2) one or more fluoroolefins other than CTFE having 2 to 8 carbon atoms, particularly TFE or HFP, and (3) a perfluoro(alkyl vinyl ether) having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms.

[0560] The CTFE polymer may also be a copolymer of CTFE and one or more non-fluorine-containing monomers. Examples of the non-fluorine-containing monomers include olefins such as ethylene and propylene; vinyl esters; and vinyl ethers.

[0561] The fluoropolymers can be glassy, ​​plastic, or elastomeric. These fluoropolymers can be amorphous or partially crystalline and can be subjected to compression sintering, melt processing, or non-melt processing.

[0562] In the above polymerization, for example, (I) a non-melt-processable fluororesin such as tetrafluoroethylene polymer [TFE polymer (PTFE)], (II) a melt-processable fluororesin such as ethylene / TFE copolymer [ETFE], TFE / HFP copolymer [FEP], TFE / perfluoro(alkyl vinyl ether) copolymer [PFA, MFA, etc.], TFE / perfluoroallyl ether copolymer, TFE / VDF copolymer, and electrolyte polymer precursor can be suitably produced, (III) a fluororubber such as TFE / propylene copolymer, TFE / propylene / third monomer copolymer (the above-mentioned third monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ether, etc.), copolymers composed of TFE and fluoroalkyl vinyl ethers; HFP / ethylene copolymer, HFP / ethylene / TFE copolymer; PVDF; thermoplastic elastomers such as VDF / HFP copolymer, HFP / ethylene copolymer, and VDF / TFE / HFP copolymer; and fluorine-containing segmented polymers described in Japanese Patent Publication No. 61-49327 can be suitably produced.

[0563] As the fluoropolymer, a fluororesin is preferred, among which a fluororesin having a fluorine substitution rate of 50% or more as calculated by the following formula is more preferred, a fluororesin having a fluorine substitution rate exceeding 50% is further preferred, a fluororesin having a fluorine substitution rate of 55% or more is further preferred, a fluororesin having a fluorine substitution rate of 60% or more is further preferred, a fluororesin having a fluorine substitution rate of 75% or more is further preferred, a fluororesin having a fluorine substitution rate of 80% or more is particularly preferred, and a fluororesin having a fluorine substitution rate of 90 to 100%, i.e., a perfluororesin, is most preferred.

[0564] (Mode)

[0565] Fluorine substitution rate (%) = (number of fluorine atoms bonded to carbon atoms constituting the fluoropolymer) / ((number of hydrogen atoms bonded to carbon atoms constituting the fluoropolymer) + (number of fluorine atoms and chlorine atoms bonded to carbon atoms constituting the fluoropolymer)) × 100

[0566] As the perfluororesin, a fluororesin having a fluorine substitution rate of 95 to 100% is more preferred, PTFE, FEP, and PFA are further preferred, PTFE is particularly preferred, and high-molecular-weight PTFE is most preferred.

[0567] The fluoropolymer may have a core-shell structure. Examples of fluoropolymers having a core-shell structure include PTFE particles comprising a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE. Examples of such PTFE include the PTFEs described in Japanese Unexamined Patent Application Publication No. 2005-527652.

[0568] The core-shell structure may have the following structures.

[0569] Core: TFE homopolymer Shell: TFE homopolymer

[0570] Core: modified PTFE Shell: TFE homopolymer

[0571] Core: modified PTFE Shell: modified PTFE

[0572] Core: TFE homopolymer Shell: modified PTFE

[0573] Core: low molecular weight PTFE Shell: high molecular weight PTFE

[0574] Core: High molecular weight PTFE Shell: Low molecular weight PTFE

[0575] In the fluoropolymer having a core-shell structure, the lower limit of the core ratio is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the core ratio is preferably 99.5% by mass, more preferably 99.0% by mass, even more preferably 98.0% by mass, even more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

[0576] In the fluoropolymer having the core-shell structure, the lower limit of the shell ratio is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the shell ratio is preferably 99.5% by mass, more preferably 99.0% by mass, even more preferably 98.0% by mass, even more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

[0577] In the fluoropolymer having the core-shell structure, the core or the shell may be formed into a structure having two or more layers. For example, the fluoropolymer may have a three-layer structure having a core center portion of modified PTFE, a core outer layer portion of a TFE homopolymer, and a shell of modified PTFE.

[0578] Examples of the fluoropolymer having the core-shell structure include fluoropolymers in which one particle of the fluoropolymer has a plurality of cores.

[0579] The above-mentioned (I) non-melt-processable fluororesin, (II) melt-processable fluororesin, and (III) fluororubber are preferably produced as follows.

[0580] (I) Non-melt-processable fluororesins

[0581] In the production method of the present invention, TFE polymerization is generally carried out at a polymerization temperature of 10 to 150°C and a polymerization pressure of 0.05 to 5 MPaG. For example, the polymerization temperature is more preferably 30°C or higher, and even more preferably 50°C or higher. Furthermore, it is more preferably 120°C or lower, and even more preferably 100°C or lower. Furthermore, the polymerization pressure is more preferably 0.3 MPaG or higher, and even more preferably 0.5 MPaG or higher, and even more preferably 5.0 MPaG or lower, and even more preferably 3.0 MPaG or lower. In particular, from the perspective of increasing the yield of the fluoropolymer, the polymerization pressure is preferably 1.0 MPaG or higher, more preferably 1.2 MPaG or higher, even more preferably 1.5 MPaG or higher, and even more preferably 2.0 MPaG or higher.

[0582] In one embodiment, during the polymerization, pure water is added to a pressure-resistant reaction vessel equipped with a stirrer, deoxygenated, and then TFE is added. The temperature is adjusted to a predetermined value, and a polymerization initiator is added to initiate the reaction. If the pressure decreases as the reaction proceeds, additional TFE is supplied continuously or intermittently to maintain the initial pressure. When the predetermined amount of TFE has been supplied, the supply is stopped, the TFE in the reaction vessel is purged, the temperature is returned to room temperature, and the reaction is terminated. To prevent the pressure from decreasing, additional TFE may be supplied continuously or intermittently.

[0583] In the manufacture of the above-mentioned TFE polymer (PTFE), various known modified monomers can also be used in combination. In this specification, the above-mentioned TFE polymer is a concept that includes not only TFE homopolymers but also non-melt-processable substances (hereinafter referred to as "modified PTFE") that are copolymers of TFE and modified monomers.

[0584] Examples of the modifying monomer include perhaloolefins such as HFP and CTFE; fluoroalkyl vinyl ethers having an alkyl group containing 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; cyclic fluorinated monomers such as fluoro-1,3-dioxole; perhaloalkylethylenes; and ω-hydrogenated perhaloolefins. The modifying monomer can be added initially in a single addition, or added continuously or intermittently in divided portions, depending on the intended purpose and the supply of TFE.

[0585] When the above-mentioned TFE polymer is polytetrafluoroethylene (PTFE), in addition to TFE, various existing known modified monomers can also be used in combination. In this specification, the above-mentioned PTFE is a concept that includes not only TFE homopolymers but also non-melt-processable materials (hereinafter referred to as "modified PTFE") as copolymers of TFE and modified monomers.

[0586] The total amount of the modified monomer units is preferably in the range of 0.00001 to 1.0 mass % relative to the total polymerized units of PTFE. As the lower limit of the above-mentioned total amount, 0.0001 mass % is more preferred, 0.001 mass % is further preferred, and 0.005 mass % is further more preferred. As the upper limit, the preferred order is 0.90 mass %, 0.50 mass %, 0.40 mass %, 0.30 mass %, 0.20 mass %, 0.15 mass %, 0.10 mass %, and 0.05 mass %.

[0587] In this specification, the modified monomer unit refers to a portion that is a part of the molecular structure of the TFE polymer and is derived from a modified monomer.

[0588] Examples of the modifying monomer include perhaloolefins such as HFP, CTFE, and perfluorovinyl ether; fluoro(alkyl vinyl ethers) having an alkyl group containing 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; cyclic fluorinated monomers such as fluoro-1,3-dioxole; perhaloalkylethylenes such as (perfluoroalkyl)ethylene; and ω-hydrogenated perhaloolefins. The modifying monomer can be added initially in a single addition, or added continuously or intermittently in divided portions, depending on the intended purpose and the supply of TFE.

[0589] The modifying monomer is not particularly limited as long as it can copolymerize with TFE, and examples thereof include fluorine-containing monomers and fluorine-free monomers.

[0590] The fluorine-free monomer is not particularly limited, but examples thereof include the following:

[0591] CH2=CR Q1 -LR Q2

[0592] (Where R Q1 represents a hydrogen atom or an alkyl group. L represents a single bond, -CO-O-*, -O-CO-* or -O-. * represents the same Q2 The bonding position of R Q2 represents a hydrogen atom, an alkyl group or a nitrile group. ) represents a monomer.

[0593] Examples of the fluorine-free monomer include methacrylate, 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. Among the fluorine-free monomer, butyl methacrylate, vinyl acetate, and acrylic acid are preferred.

[0594] Examples of the fluorinated monomer include perfluoroolefins such as hexafluoropropylene [HFP]; hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride [VDF]; perhalogenated olefins such as chlorotrifluoroethylene; perfluorovinyl ether; (perfluoroalkyl)ethylene; and perfluoroallyl ether.

[0595] The perfluorovinyl ether is not particularly limited, and examples thereof include the following general formula (3A):

[0596] CF2=CF-ORf(3A)

[0597] (wherein Rf represents a perfluoroorganic group.) In this specification, the above-mentioned "perfluoroorganic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. The above-mentioned perfluoroorganic group may have an ethereal oxygen.

[0598] Examples of the perfluorovinyl ether include perfluoro(alkyl vinyl ether) [PAVE], wherein Rf in the general formula (3A) is a perfluoroalkyl group having 1 to 10 carbon atoms. The perfluoroalkyl group preferably has 1 to 5 carbon atoms.

[0599] Examples of the perfluoroalkyl group in PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

[0600] As the perfluorovinyl ether, further examples include those wherein Rf in the general formula (3A) is a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, and Rf is the following formula:

[0601] [Chemistry 8]

[0602]

[0603] (wherein m represents 0 or an integer of 1 to 4.) The substance of the group represented by is represented by Rf as follows:

[0604] [Chemistry 9]

[0605]

[0606] (wherein n represents an integer of 1 to 4.)

[0607] Examples of the hydrogen-containing fluoroolefins include CH2=CF2, CFH=CH2, CFH=CF2, CF2=CFCF3, CH2=CFCF3, CH2=CHCF3, CHF=CHCF3 (E-isomer), and CHF=CHCF3 (Z-isomer).

[0608] The (perfluoroalkyl)ethylene (PFAE) is not particularly limited, and examples thereof include (perfluorobutyl)ethylene (PFBE) and (perfluorohexyl)ethylene.

[0609] Examples of perfluoroallyl ether include

[0610] General formula: CF2=CF-CF2-ORf

[0611] (wherein Rf represents a perfluoro organic group.) A fluorine monomer represented by.

[0612] Rf in the above general formula is the same as Rf in general formula (A). As Rf, a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms is preferred. As the 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 preferred, 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 preferred, and CF2=CF-CF2-O-CF2CF2CF3 is further preferred.

[0613] In addition, when TFE is used as a fluoromonomer to produce PTFE as a fluoropolymer, by allowing the polymerization system to contain (polyfluoroalkyl)ethylene in an amount of 0.001 to 0.01 mass % relative to the final amount of PTFE produced, and / or a comonomer (3) having a monomer reactivity ratio rTFE with TFE of 0.1 to 8 in copolymerization, it is possible to produce an aqueous PTFE dispersion having high stability to such an extent that subsequent processability, moldability, etc. are not impaired, and an aqueous PTFE dispersion can be obtained that can produce a molded product with high heat resistance.

[0614] Here, the monomer reactivity ratio in copolymerization with TFE refers to the value obtained by dividing the rate constant of the reaction of the propagating free radical with TFE by the rate constant of the reaction of the propagating free radical with the comonomer when the propagating free radical is smaller than the repeating unit based on TFE. The lower this value, the higher the reactivity of the comonomer with TFE. The reactivity ratio can be calculated by copolymerizing the comonomer with TFE at various feed compositions, determining the composition of the resulting polymer immediately after the start of the copolymerization, and then calculating the reactivity ratio using the Fineman-Ross equation based on the composition.

[0615] The copolymerization was carried out in a stainless steel autoclave with an internal volume of 6.0 L, using 3600 g of deionized and degassed water, 1000 ppm of ammonium perfluorooctanoate relative to the water, and 100 g of paraffin wax at a pressure of 0.78 MPaG and a temperature of 70°C. 0.05 g, 0.1 g, 0.2 g, 0.5 g, and 1.0 g of the comonomer were added to the reactor, respectively, along with 0.072 g of ammonium persulfate (20 ppm relative to the water). TFE was continuously supplied to maintain a polymerization pressure of 0.78 MPaG. When the TFE charge reached 1000 g, stirring was stopped and the reactor was depressurized until atmospheric pressure was reached. After cooling, the paraffin wax was separated to obtain an aqueous dispersion containing the generated polymer. The aqueous dispersion was stirred to precipitate the generated polymer and then dried at 150°C. The composition of the resulting polymer was calculated using an appropriate combination of NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

[0616] Preferred examples of the modifying monomer include comonomers (3) having a monomer reactivity ratio of 0.1 to 8. The presence of comonomers (3) allows for the production of PTFE particles with a small particle size and an aqueous dispersion having high dispersion stability.

[0617] The comonomer (3) having a monomer reactivity ratio of 0.1 to 8 is preferably at least one selected from the group consisting of comonomers represented by formulas (3a) to (3d). 1 (3a)

[0618] (Where Rf 1 It is a perfluoroalkyl group having 1 to 10 carbon atoms.)

[0619] CF2=CF-O-Rf 2 (3b)

[0620] (Where Rf 2 It is a perfluoroalkyl group having 1 to 2 carbon atoms.

[0621] CF2=CF-O-(CF2) n CF=CF2(3c)

[0622] (Where n is 1 or 2.)

[0623] [Chemistry 10]

[0624]

[0625] (Where X 3 and X 4 is F, Cl or methoxy, and Y is of the formula Y1 or Y2.)

[0626] [Chemistry 11]

[0627] -CF==CF- (Y1)

[0628]

[0629] (In formula Y2, Z and Z' are F or a fluorinated alkyl group having 1 to 3 carbon atoms.)

[0630] The content of the comonomer (3) unit is preferably in the range of 0.0001 to 1.0 mass % relative to the total polymerized units of PTFE. As the lower limit, 0.0001 mass % is more preferred, 0.0005 mass % is further preferred, 0.001 mass % is still more preferred, and 0.005 mass % is particularly preferred. As the upper limit, the preferred order is 0.90 mass %, 0.50 mass %, 0.40 mass %, 0.30 mass %, 0.20 mass %, 0.15 mass %, 0.10 mass %, 0.08 mass %, 0.05 mass %, and 0.01 mass %.

[0631] As the modifying monomer, at least one selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, perfluoro(alkyl vinyl ether), (perfluoroalkyl)ethylene, ethylene, and a modifying monomer having a functional group capable of reacting in free radical polymerization and a hydrophilic group is preferred, in order to obtain an aqueous dispersion having a small average primary particle size, a small aspect ratio of primary particles, and excellent stability. By using such a modifying monomer, an aqueous dispersion of PTFE having a small average primary particle size, a small aspect ratio of primary particles, and excellent dispersion stability can be obtained.

[0632] From the viewpoint of reactivity with TFE, the modifying monomer preferably contains at least one selected from the group consisting of hexafluoropropylene, perfluoro(alkyl vinyl ether) and (perfluoroalkyl)ethylene.

[0633] More preferably, it contains at least one selected from the group consisting of hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(propyl vinyl ether), (perfluorobutyl)ethylene, (perfluorohexyl)ethylene, and (perfluorooctyl)ethylene.

[0634] Relative to the total polymerized units of PTFE, the total amount of above-mentioned hexafluoropropylene unit, perfluoro (alkyl vinyl ether) unit and (perfluoroalkyl) ethylene unit is preferably in the range of 0.00001~1.0 mass %.As the lower limit of above-mentioned total amount, more preferably 0.0001 mass %, further preferably 0.0005 mass %, further more preferably 0.001 mass %, especially more preferably 0.005 mass %, particularly preferably 0.009 mass %.As the upper limit, preferred order is 0.9 mass %, 0.50 mass %, 0.40 mass %, 0.30 mass %, 0.20 mass %, 0.15 mass %, 0.10 mass %, 0.08 mass %, 0.05 mass %, 0.01 mass %.

[0635] The above-mentioned modified monomers preferably further include a modified monomer having a functional group capable of reacting in radical polymerization and a hydrophilic group (hereinafter referred to as "modified monomer (A)").

[0636] The presence of the modifying monomer (A) can provide PTFE particles with a small primary particle size, an aqueous dispersion with high dispersion stability, and a reduced aspect ratio of the primary particles.

[0637] The amount of the modified monomer (A) is preferably an amount exceeding 0.1 ppm of the aqueous medium, more preferably an amount exceeding 0.5 ppm, further preferably an amount exceeding 1.0 ppm, further more preferably 5 ppm or more, and particularly preferably 10 ppm or more. If the amount of the modified monomer (A) is too small, the particle size of the resulting PTFE may not be reduced.

[0638] The amount of the modified monomer (A) may be within the above range, and the upper limit may be 5000 ppm. In addition, in the above production method, in order to improve the stability of the aqueous dispersion during or after the reaction, the modified monomer (A) may be added to the system during the reaction.

[0639] Since the modified monomer (A) is highly water-soluble, even if unreacted modified monomer (A) remains in the aqueous dispersion, it can be easily removed by a concentration step or a coagulation and washing step.

[0640] The modified monomer (A) is introduced into the resulting polymer during the polymerization process. However, since the concentration of the modified monomer (A) in the polymerization system is low and the amount introduced into the polymer is small, there is no problem of reduced heat resistance of PTFE or coloration after firing.

[0641] Examples of the hydrophilic group in the modified monomer (A) include -NH2, -PO3M, -P(O)(OM)2, -OPO3M, -OP(O)(OM)2, -SO3M, -OSO3M, and -COOM (wherein M is H, a metal atom, NR 7 4. an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted; R 7 (a) H or an organic group, which may be the same or different. Any two of them may be combined to form a ring.) As the above-mentioned hydrophilic group, -SO3M or -COOM is preferred.

[0642] As R 7 The organic group in is preferably an alkyl group. 7 , preferably H or C 1-10 An organic group, more preferably H or C 1-4 The organic group is preferably H or C 1-4 of alkyl.

[0643] 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 preferred.

[0644] Examples of the "functional group capable of reacting in free 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:

[0645] CX1X3=CX2R-

[0646] (wherein, X1, X2 and X3 are each independently F, Cl, H, CF3, CF2H, CFH2 or CH3; R is a linking group.) a connecting group.

[0647] Preferred examples include -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, etc. having an unsaturated bond.

[0648] Since the modified monomer (A) has a functional group capable of reacting in free radical polymerization, it is presumed that when used in the polymerization, it reacts with the fluorinated monomer in the early stages of the polymerization reaction to form highly stable particles having hydrophilic groups derived from the modified monomer (A). Therefore, it is believed that the number of particles increases when polymerization is carried out in the presence of the modified monomer (A).

[0649] In the above polymerization, the above-mentioned modifying monomer (A) may be present alone or in combination of two or more.

[0650] In the above polymerization, a compound having an unsaturated bond can be used as the above-mentioned modifying monomer (A).

[0651] The modified monomer (A) is preferably at least one selected from the group consisting of compounds represented by general formula (4A).

[0652] CX 1 X 3 =CX 2 R a -(CZ 1 Z 2 ) k -Y 3 (4A)

[0653] (Where X 1 、X 2 and X 3 are each independently F, Cl, H or CF3; Y 3 is a hydrophilic group; R a is a connecting group; Z 1 and Z 2 are each independently H, F or CF3, k is 0 or 1)

[0654] Examples of the hydrophilic group include -NH2, -PO3M, -P(O)(OM)2, -OPO3M, -OP(O)(OM)2, -SO3M, -OSO3M, and -COOM (wherein M is H, a metal atom, NR 7 4. an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted; R 7 R is H or an organic group, which may be the same or different. Any two of them may be combined to form a ring. As the above-mentioned hydrophilic group, -SO3M or -COOM is preferred. 7 , preferably H or C 1-10 An organic group, more preferably H or C 1-4 The organic group is preferably H or C 1-4 of alkyl.

[0655] 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 preferred.

[0656] By using the modified monomer (A), an aqueous dispersion having a smaller average primary particle size and better stability can be obtained, and the aspect ratio of the primary particles can also be further reduced.

[0657] The above R a is a linking group. In this specification, "linking group" refers to a divalent linking group. The linking group may be a single bond and preferably contains at least one carbon atom. The number of carbon atoms may be 2 or more, 4 or more, 8 or more, 10 or more, or 20 or more. The upper limit is not limited, for example, it may be 100 or less, or 50 or less.

[0658] The linking group may be a chain or branched chain, a cyclic or acyclic structure, saturated or unsaturated, substituted or unsubstituted, and may contain one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen as desired, and may contain one or more functional groups selected from the group consisting of esters, amides, sulfonamides, carbonyls, carbonates, urethanes, ureas, and carbamates as desired. The linking group does not contain carbon atoms and may be a catenary heteroatom such as oxygen, sulfur, or nitrogen.

[0659] The above R a For example, a catenary hetero atom such as oxygen, sulfur, or nitrogen, or a divalent organic group is preferred.

[0660] R a In the case of a divalent organic group, the hydrogen atom bonded to the carbon atom may be substituted by a halogen other than fluorine, such as chlorine, and may or may not contain a double bond.a It can be any of chain and branched, and any of cyclic and acyclic. a Functional groups (eg, ester, ether, ketone, amine, halide, etc.) may be included.

[0661] In addition, R a It may be a fluorine-free divalent organic group or a partially fluorinated or perfluorinated divalent organic group.

[0662] As R a , for example, it can be a hydrocarbon group in which no fluorine atoms are bonded to the carbon atom, a hydrocarbon group in which a part of the hydrogen atoms bonded to the carbon atom are substituted by fluorine atoms, a hydrocarbon group in which all the hydrogen atoms bonded to the carbon atom are substituted by fluorine atoms, a hydrocarbon group containing -(C=O)-, -(C=O)-O- or -(C=O)-, and these hydrocarbon groups can contain oxygen atoms, double bonds, and functional groups.

[0663] R a A hydrocarbon group having 1 to 100 carbon atoms which may contain -(C=O)-, -(C=O)-O- or an ether bond, preferably may contain -(C=O)-, wherein the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be partially or completely substituted with fluorine.

[0664] As R a , preferably selected from -(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 At least one of -, -(C=O)-O-C6H4-, and combinations thereof.

[0665] In the formula, a, b, c, and d are independently at least 1. a, b, c, and d may independently be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limit of a, b, c, and d is, for example, 100.

[0666] As R aPreferred 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-, -(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-.

[0667] In the above formula, n is an integer of 1-10.

[0668] As -R in the above general formula (4A) a -(CZ 1 Z 2 ) k, preferably -CF2-O-CF2-, -CF2-O-CF(CF3)-, -CF2-O-C(CF3)2-, -CF2-O-CF2-CF2-, -CF2-O-CF2-CF(CF3)-, -CF2-O-CF2-C(CF3)2-, -CF2-O-CF2CF2-CF2-, -CF2-O-CF2CF2-CF(CF3)-, -CF2-O-CF2CF2-C(CF3)2-, -CF2-O-CF(CF3)-CF2-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF3)-C(CF3)2-, -CF2-O-CF(CF3)-CF2-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF3)-C(CF3)2-, -CF2-O-CF(CF3)CF2-CF2-, -CF2-O-CF(CF3)CF2-CF(CF3)-, -CF2-O-CF(CF3)CF2-C(CF3)2-, -CF2-O-CF(CF3)CF2-O-CF2-, -CF2-O-CF(CF3)CF2-O-CF(CF3)-, -CF2-O-CF(CF3)CF2-O-C(CF3)2-, -(C=O)-, -(C=O)-O-, -(C=O)-(CH2)-, -(C=O)-(CF2)-, -(C=O)-O-(CH2)-, -(C=O)-O-(CF2)-, -(C=O)-[(CH2)2-O] n -(CH2)-, -(C=O)-[(CF2)2-O] n -(CF2)-, -(C=O)-[(CH2)2-O] n -(CH2)-(CH2)-, -(C=O)-[(CF2)2-O] n -(CF2)-(CF2)-, -(C=O)-O[(CH2)2-O] n -(CF2)-, -(C=O)-O[(CH2)2-O] n -(CH2)-(CH2)-, -(C=O)-O[(CF2)2-O] n -(CF2)-, -(C=O)-O[(CF2)2-O] n-(CF2)-(CF2)-, -(C=O)-(CH2)2-O-(CH2)-(CH2)-, -(C=O)-(CF2)2-O-(CF2)-(CF2)-, -(C=O)-O-(CH2)2-O-(CH2)-(CH2)-, -(C= O)-O-(CF2)2-O-(CF2)-(CF2)-, -(C=O)-O-(CH2)2-O-(CH2)-C(CF3)2-, -(C=O)-O-(CF2)2-O-(CF2)-C(CF3)2- or -(C=O)-O-C6H4- C(CF3)2-, more preferably -CF2-O-CF(CF3)-, -CF2-O-CF2-CF(CF3)-, -CF2-O-CF2CF2-CF(CF3)-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF 3)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-.

[0669] In the above formula, n is an integer of 1-10.

[0670] Specific examples of the compound represented by the general formula (4A) include

[0671] [Chemistry 12]

[0672]

[0673] (Where X j and Y 3 Same as above. n is an integer from 1 to 10. ) etc.

[0674] As R a , preferably the following general formula (r1):

[0675] -(C=O) h -(O) i -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g -(r1)

[0676] (Where X 6Each independently represents H, F or CF3, e is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1), and the following general formula (r2) is also preferred:

[0677] -(C=O) h -(O) i -CF2-O-(CX 7 2) e -(O) g -(r2)(where X 7 Each independently represents H, F or CF3, e is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1. ) is a divalent group represented by.

[0678] In addition, -R a -(CZ 1 Z 2 ) k -, the following formula (t1) is also preferred:

[0679] -(C=O) h -(O) i -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g -CZ 1 Z 2 - (t1)

[0680] (Where X 6 Each independently represents H, F or CF3, e represents an integer from 0 to 3, f represents an integer from 0 to 3, g represents 0 or 1, h represents 0 or 1, i represents 0 or 1, Z 1 and Z 2 Each independently represents a divalent group represented by F or CF3), in formula (t1), Z is more preferably 1 and Z 2 One of them is F and the other is CF3.

[0681] In the above general formula (4A), -R a -(CZ 1 Z 2 ) k -, the following formula (t2) is also preferred:

[0682] -(C=O) h -(O) i -CF2-O-(CX 7 2) e -(O) g -CZ 1 Z2 - (t2)

[0683] (Where X 7 Each independently represents H, F or CF3, e represents an integer from 0 to 3, g represents 0 or 1, h represents 0 or 1, i represents 0 or 1, Z 1 and Z 2 Each independently represents a divalent group represented by H, F or CF3, in formula (t2), Z is more preferably 1 and Z 2 One of them is F and the other is CF3.

[0684] The compound represented by the general formula (4A) preferably has, in addition to the hydrophilic group (Y 3 ) has a CF bond but does not have a CH bond. That is, in the general formula (4A), it is preferred that X i 、X j and X k All are F, R a The perfluoroalkylene group is a perfluoroalkylene group having 1 or more carbon atoms. The perfluoroalkylene group may be either linear or branched, cyclic or acyclic, and may contain at least one catenary heteroatom. The perfluoroalkylene group may have 2 to 20 carbon atoms, or 4 to 18 carbon atoms.

[0685] The compound represented by the general formula (4A) may be partially fluorinated. That is, the compound represented by the general formula (4A) preferably has, in addition to the hydrophilic group (Y 3 ) has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0686] The compound represented by the general formula (4A) is preferably a compound represented by the following formula (4a).

[0687] CF2=CF-O-Rf 0 -Y 3 (4a)

[0688] (where Y 3 is a hydrophilic group, Rf 0 It is a perfluorinated, chain- or branched-chain, cyclic or acyclic structure, saturated or unsaturated, substituted or unsubstituted perfluorinated divalent linking group that optionally contains one or more heteroatoms selected from the group consisting of sulfur, oxygen and nitrogen.

[0689] The compound represented by the general formula (4A) is preferably a compound represented by the following formula (4b).

[0690] CH2=CH-O-Rf 0 -Y 3 (4b)

[0691] (where Y 3 is a hydrophilic group, Rf 0 is a perfluorinated divalent linking group defined in formula (4a).

[0692] In the general formula (4A), Y 3 -OSO3M is one of the preferred methods. 3 In the case of -OSO3M, examples of the compound represented by the general formula (4A) include CF2=CF(OCF2CF2CH2OSO3M), CH2=CH((CF2)4CH2OSO3M), CF2=CF(O(CF2)4CH2OSO3M), CF2=CF(OCF2CF(CF3)CH2OSO3M), CF2=CF(OCF2CF(CF3)OCF2CF2CH2OSO3M), CH2=CH((CF2)4CH2OSO3M), CF2=CF(OCF2CF2SO2N(CH3)CH2CH2OSO3M), CH2=CH(CF2CF2CH2OSO3M), CF2=CF(OCF2CF2CF2CF2SO2N(CH3)CH2CH2OSO3M), and CH2=CH(CF2CF2CH2OSO3M). In the above formulae, M is the same as above.

[0693] In the general formula (4A), Y 3 -SO3M is also one of the preferred methods. 3 In the case of -SO3M, examples of the compound represented by the general formula (4A) include CF2=CF(OCF2CF2SO3M), CF2=CF(O(CF2)4SO3M), CF2=CF(OCF2CF(CF3)SO3M), CF2=CF(OCF2CF(CF3)OCF2CF2SO3M), CH2=CH(CF2CF2SO3M), CF2=CF(OCF2CF(CF3)OCF2CF2CF2SO3M), CH2=CH((CF2)4SO3M), CH2=CH(CF2CF2SO3M), and CH2=CH((CF2)3SO3M). In the above formulae, M is the same as above.

[0694] In the general formula (4A), Y 3 -COOM is also one of the preferred methods. 3In the case of -COOM, examples of the compound represented by the general formula (4A) include CF2=CF(OCF2CF2COOM), CF2=CF(OCF2CF2CF2COOM), CF2=CF(O(CF2)5COOM), CF2=CF(OCF2CF(CF3)COOM), CF2=CF(OCF2CF(CF3)O(CF2) n COOM) (n is greater than 1), CH2=CH(CF2CF2COOM), CH2=CH((CF2)4COOM), CH2=CH(CF2CF2COOM), CH2=CH((CF2)3COOM), CF2=CF (OCF2CF2SO2NR'CH2COOM), CF2=CF(O(CF2)4SO2NR'CH2COOM), CF2=CF(OCF2CF(CF3)SO2NR'CH2COOM), CF2=CF(OCF 2CF(CF3)OCF2CF2SO2NR'CH2COOM), CH2=CH(CF2CF2SO2NR'CH2COOM), CF2=CF(OCF2CF(CF3)OCF2CF2CF2CF2SO2NR'CH2COOM), CH2=CH((CF2)4SO2NR'CH2COOM), CH2=CH(CF2CF2SO2NR'CH2COOM), CH2=CH((CF2)3SO2NR'CH2COOM), etc. In the above formula, R' is H or C 1-4 The alkyl group and M are the same as those described above.

[0695] In the general formula (4A), Y 3 -OPO3M or -OP(O)(OM)2 is also one of the preferred forms. 3In the case of -OPO3M or -OP(O)(OM)2, examples of the compound represented by the general formula (4A) include CF2=CF(OCF2CF2CH2OP(O)(OM)2), CF2=CF(O(CF2)4CH2OP(O)(OM)2), CF2=CF(OCF2CF(CF3)CH2OP(O)(OM)2), CF2=CF(OCF2CF(CF3)OCF2CF2CH2OP(O)(OM)2), CF2=CF(OCF2CF2SO2N (CH3)CH2CH2OP(O)(OM)2), CF2=CF(OCF2CF2CF2CF2SO2N(CH3)CH2CH2OP(O)(OM)2), CH2=CH(CF2CF2CH2OP(O)(OM)2, CH2=CH((CF2)4CH2OP(O)(OM)2), CH2=CH(CF2CF2CH2OP(O)(OM)2), CH2=CH((CF2)3CH2OP(O)(OM)2), etc. In the above formulae, M is the same as above.

[0696] In the general formula (4A), Y 3 -PO3M or -P(O)(OM)2 is also one of the preferred forms. 3 In the case of -PO3M or -P(O)(OM)2, examples of the compound represented by the general formula (4A) include CF2=CF(OCF2CF2P(O)(OM)2), CF2=CF(O(CF2)4P(O)(OM)2), CF2=CF(OCF2CF(CF3)P(O)(OM)2), CF2=CF(OCF2CF(CF3)OCF2CF2P(O)(OM)2), CH2=CH(CF2CF2P(O)(OM)2), CH2=CH((CF2)4P(O)(OM)2), CH2=CH(CF2CF2P(O)(OM)2), CH2=CH((CF2)3P(O)(OM)2), etc., wherein M is the same as above.

[0697] The compound represented by the general formula (4A) is preferably selected from the following general formula (5A):

[0698] CX2=CY(-CZ2-O-Rf-Y 3 )(5A)

[0699] (wherein, X is the same or different -H or -F, Y is -H, -F, alkyl or fluorinated alkyl, and Z is the same or different -H, -F, alkyl or fluorinated alkyl. Rf is a fluorinated alkylene group having 1 to 40 carbon atoms, or a fluorinated alkylene group having 2 to 100 carbon atoms and having an ether bond. Y 3Same as above. ) represented by the following general formula (6A):

[0700] CX2=CY(-O-Rf-Y 3 )(6A)

[0701] (wherein, X is the same or different -H or -F, Y is -H, -F, alkyl or fluorinated alkyl, Rf is a fluorinated alkylene group having 1 to 40 carbon atoms, or a fluorinated alkylene group having 2 to 100 carbon atoms and having an ether bond. 3 Same as above. ) and the following general formula (7A):

[0702] CX2=CY(-Rf-Y 3 )(7A)

[0703] (wherein, X is the same or different -H or -F, Y is -H, -F, alkyl or fluorinated alkyl, Rf is a fluorinated alkylene group having 1 to 40 carbon atoms, or a fluorinated alkylene group having 2 to 100 carbon atoms and having an ether bond. 3 Same as above. ) At least one of the group consisting of monomers represented by ).

[0704] In the above general formula (5A), X is -H or -F. Both X may be -H, both 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.

[0705] In the above general formula (5A), Y is -H, -F, an alkyl group or a fluorine-containing alkyl group.

[0706] The alkyl group does not contain fluorine atoms and may have at least 1 carbon atom. The alkyl group preferably has 6 or less carbon atoms, more preferably 4 or less carbon atoms, and even more preferably 3 or less carbon atoms.

[0707] The fluorinated alkyl group is an alkyl group containing at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms in the fluorinated alkyl group is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less.

[0708] As the above-mentioned Y, -H, -F or -CF3 is preferred, and -F is more preferred.

[0709] In the above general formula (5A), Z is the same or different and represents -H, -F, alkyl or fluoroalkyl.

[0710] The alkyl group does not contain fluorine atoms and may have at least 1 carbon atom. The alkyl group preferably has 6 or less carbon atoms, more preferably 4 or less carbon atoms, and even more preferably 3 or less carbon atoms.

[0711] The fluorinated alkyl group is an alkyl group containing at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms in the fluorinated alkyl group is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less.

[0712] As the above-mentioned Z, -H, -F or -CF3 is preferred, and -F is more preferred.

[0713] In the general formula (5A), it is preferred that at least one of X, Y, and Z is a fluorine atom. For example, X may be -H, and Y and Z may be -F.

[0714] In the general formula (5A), Rf is a fluorinated alkylene group having 1 to 40 carbon atoms or a fluorinated alkylene group having 2 to 100 carbon atoms and having an ether bond.

[0715] The number of carbon atoms in the fluorinated alkylene group is preferably 2 or more. In addition, it is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. Examples of the fluorinated alkylene group include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, and -CF(CF3)CH2-. The fluorinated alkylene group is preferably a perfluoroalkylene group.

[0716] The number of carbon atoms in the fluorinated alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms in the fluorinated alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, and even more preferably 12 or less.

[0717] As the fluorine-containing alkylene group having an ether bond, for example, the following formula is also preferred:

[0718] [Chemistry 13]

[0719]

[0720] (Where Z 1 F or CF3; Z 2 and Z 3 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).

[0721] Specific examples of the fluorine-containing alkylene group having an ether bond include -CF(CF3)CF2-O-CF(CF3)-, -(CF(CF3)CF2-O) n -CF(CF3)- (wherein n is an integer from 1 to 10), -CF(CF3)CF2-O-CF(CF3)CH2-, -(CF(CF3)CF2-O)n -CF(CF3)CH2- (wherein n is an integer of 1 to 10), -CH2CF2CF2O-CH2CF2CH2-, -CF2CF2CF2O-CF2CF2-, -CF2CF2CF2O-CF2CF2CH2-, -CF2CF2O-CF2-, -CF2CF2O-CF2CH2-, etc. The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0722] In the above general formula (5A), Y 3 Preferably -COOM, -SO3M or -OSO3M (M is H, metal atom, NR 7 4. an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted; R 7 is H or an organic group, which may be the same or different. Any two of them may be combined to form a ring.

[0723] As R 7 The organic group in is preferably an alkyl group. 7 , preferably H or C 1-10 An organic group, more preferably H or C 1-4 The organic group is preferably H or C 1-4 of alkyl.

[0724] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred.

[0725] As the above-mentioned M, -H, a metal atom or -NR 7 4, more preferably -H, alkali metal (Group 1), alkaline earth metal (Group 2) or -NR 7 4, further preferably -H, -Na, -K, -Li or -NH4, further more preferably -Na, -K or -NH4, particularly preferably -Na or -NH4, most preferably -NH4.

[0726] As the above Y 3 , preferably -COOM or -SO3M, more preferably -COOM.

[0727] The monomer represented by the general formula (5A) is preferably a monomer (5a) represented by the following general formula (5a).

[0728] CH2=CF(-CF2-O-Rf-Y 3 )(5a)

[0729] (Where Rf and Y 3 Same as above.)

[0730] Specific examples of the monomer represented by general formula (5a) include the following:

[0731] [Chemistry 14]

[0732]

[0733] (Where Z 1 F or CF3; Z 2 and Z 3 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, Y 3 Same as above. Where Z 3 and Z 4 When all are H, p1+q1+r1+s1 is not 0). More specifically, preferably,

[0734] [Chemistry 15]

[0735]

[0736] CH2=CFCF2OCH2CF2-Y 3 , CH2=CFCF2O(CH2CF2CF2O)CH2CF2-Y 3 ,

[0737] CH2=CFCF2OCH2CF2CH2-Y 3 ,

[0738] CH2=CFCF2O(CH2CF2CF2O)CH2CF2CH2-Y 3 ,

[0739] CH2=CFCF2OCF2CF2-Y 3 , CH2=CFCF2O(CF2CF2CF2O)CF2CF2-Y 3 ,

[0740] CH2=CFCF2OCF2CF2CH2-Y 3 ,

[0741] CH2=CFCF2O(CF2CF2CF2O)CF2CF2CH2-Y 3 ,

[0742] CH2=CFCF2OCF2-Y 3 , CH2=CFCF2O(CF2CF2O)CF2-Y 3 ,

[0743] CH2=CFCF2OCF2CH2-Y 3 ,

[0744] CH2=CFCF2O(CF2CF2O)CF2CH2-Y 3 ,

[0745] etc., among which

[0746] [Chemistry 16]

[0747]

[0748] is preferred.

[0749] As the monomer represented by the above general formula (5a), Y in the formula (5a) 3 It is preferably -COOM, particularly preferably at least one selected from the group consisting of CH2=CFCF2OCF(CF3)COOM and CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOM (wherein M has the same meaning as above), and more preferably CH2=CFCF2OCF(CF3)COOM.

[0750] The monomer represented by the general formula (5A) is preferably a monomer (5b) represented by the following general formula (5b).

[0751] CX 2 2=CFCF2-O-(CF(CF3)CF2O) n5 -CF(CF3)-Y 3 (5b)

[0752] (Where, each X 2 The same, represents F or H. n5 represents 0 or an integer from 1 to 10, Y 3 Same as the above definition.)

[0753] In the above formula (5b), from the viewpoint of the stability of the obtained aqueous dispersion, the above n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1. 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of improving the heat resistance of the obtained molded article since the aforementioned M is less likely to remain as an impurity, H or NH 4 is preferred.

[0754] Examples of the perfluorovinyl alkyl compound represented by the formula (5b) include CH2=CFCF2OCF(CF3)COOM and CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOM (wherein M has the same meaning as defined above).

[0755] Examples of the monomer represented by the general formula (5A) include monomers represented by the following general formula (5c).

[0756] CF2=CFCF2-O-Rf-Y 3 (5c)

[0757] (Where Rf and Y 3 Same as above)

[0758] More specifically, we can cite

[0759] [Chemistry 17]

[0760] CF2=CFCF2OCF2CF2CF2-Y 3 ,

[0761]

[0762] CF2=CFCF2OCF2CF2CF2CH2-Y 3 ,

[0763]

[0764] wait.

[0765] In the above general formula (6A), 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.

[0766] In the above general formula (6A), Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group.

[0767] The alkyl group does not contain fluorine atoms and may have at least 1 carbon atom. The alkyl group preferably has 6 or less carbon atoms, more preferably 4 or less carbon atoms, and even more preferably 3 or less carbon atoms.

[0768] The fluorinated alkyl group is an alkyl group containing at least one fluorine atom, and the number of carbon atoms may be 1 or more. The number of carbon atoms in the fluorinated alkyl group is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less.

[0769] As the above-mentioned Y, -H, -F or -CF3 is preferred, and -F is more preferred.

[0770] In the general formula (6A), it is preferred that at least one of X and Y is a fluorine atom. For example, X can be -H, and Y and Z can be -F.

[0771] In the general formula (6A), Rf is a fluorinated alkylene group having 1 to 40 carbon atoms or a fluorinated alkylene group having 2 to 100 carbon atoms and having an ether bond.

[0772] The number of carbon atoms in the fluorinated alkylene group is preferably 2 or more. In addition, the number of carbon atoms in the fluorinated alkylene group is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. Examples of the fluorinated alkylene group include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, and -CF(CF3)CH2-. The fluorinated alkylene group is preferably a perfluoroalkylene group.

[0773] In the above general formula (6A), Y 3 Preferably -COOM, -SO3M or -OSO3M (M is H, metal atom, NR 7 4. an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted; R 7 is H or an organic group, which may be the same or different. Any two of them may be combined to form a ring.

[0774] As R 7 As an organic group, preferably an alkyl group. 7 , preferably H or C 1-10 An organic group, more preferably H or C 1-4 The organic group is preferably H or C 1-4 of alkyl.

[0775] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred.

[0776] As the above-mentioned M, -H, a metal atom or -NR 7 4, more preferably -H, alkali metal (Group 1), alkaline earth metal (Group 2) or -NR 7 4, further preferably -H, -Na, -K, -Li or -NH4, further more preferably -Na, -K or -NH4, particularly preferably -Na or -NH4, most preferably -NH4.

[0777] As the above Y 3 , preferably -COOM or -SO3M, more preferably -COOM.

[0778] The monomer represented by the general formula (6A) is preferably at least one selected from the group consisting of monomers represented by the following general formulae (6a), (6b), (6c), (6d), and (6e).

[0779] CF2=CF-O-(CF2) n1 -Y 3 (6a)

[0780] (where n1 represents an integer from 1 to 10, Y 3 Same as the above definition.)

[0781] CF2=CF-O-(CF2C(CF3)F) n2 -Y 3 (6b)

[0782] (where n2 represents an integer from 1 to 5, Y 3 Same as the above definition.)

[0783] CF2=CF-O-(CFX 1 ) n3 -Y 3 (6c)

[0784] (Where X 1 represents F or CF3, n3 represents an integer from 1 to 10, Y 3 Same as the above definition.)

[0785] CF2=CF-O-(CF2CFX 1 O) n4 -(CF2) n6 -Y 3 (6d)

[0786] (wherein, n4 represents an integer of 1 to 10, n6 represents an integer of 1 to 3, and Y 3 and X 1 Same as the above definition.)

[0787] CF2=CF-O-(CF2CF2CFX 1 O) n5 -CF2CF2CF2-Y 3 (6e)

[0788] (where n5 represents an integer from 0 to 10, Y 3 and X 1 Same as the above definition.)

[0789] In the above formula (6a), the above n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less. 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of less likely to remain as an impurity and improving the heat resistance of the obtained molded article, H or NH 4 is preferred.

[0790] Examples of the monomer represented by the above formula (6a) include CF2=CF-O-CF2COOM, CF2=CF(OCF2CF2COOM), and CF2=CF(OCF2CF2CF2COOM) (wherein M has the same meaning as above).

[0791] In the above formula (6b), from the perspective of the stability of the obtained aqueous dispersion, the above n2 is preferably an integer of 3 or less, and Y 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of less likely to remain as an impurity and improving the heat resistance of the obtained molded article, H or NH 4 is preferred.

[0792] In the above formula (6c), from the viewpoint of water solubility, the above n3 is preferably an integer of 5 or less, and the above Y 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of improving dispersion stability, H or NH 4 is preferred.

[0793] In the above formula (6d), from the perspective of the stability of the aqueous dispersion, the above X 1 Preferably -CF3, from the perspective of water solubility, the above n4 is preferably an integer of 5 or less, from the perspective of obtaining moderate water solubility and stability of the aqueous dispersion, the above Y 3 It is preferably -COOM, and the above-mentioned M is preferably H or NH4.

[0794] Examples of the monomer represented by the above formula (6d) include CF2=CFOCF2CF(CF3)OCF2CF2COOM, CF2=CFOCF2CF(CF3)OCF2COOM, and CF2=CFOCF2CF(CF3)OCF2CF2CF2OOM (wherein M represents H, NH4 or an alkali metal).

[0795] In the general formula (6e), from the perspective of water solubility, the above n5 is preferably an integer of 5 or less, and from the perspective of obtaining moderate water solubility and excellent sedimentation stability of the composition, the above Y 3 It is preferably -COOM, and the above-mentioned M is preferably H or NH4.

[0796] Examples of the monomer represented by the general formula (6e) include CF2=CFOCF2CF2CF2COOM (wherein M represents H, NH4 or an alkali metal).

[0797] In the above general formula (7A), Rf is preferably a fluorine-containing alkylene group having 1 to 40 carbon atoms. In the general formula (7A), at least one of X and Y is preferably a fluorine atom.

[0798] The monomer represented by the general formula (7A) is preferably selected from the following general formula (7a):

[0799] CF2=CF-(CF2) n1 -Y 3 (7a)

[0800] (where n1 represents an integer from 1 to 10, Y 3 Same as the above definition. ) and the following general formula (7b):

[0801] CF2=CF-(CF2C(CF3)F) n2 -Y 3 (7b)

[0802] (where n2 represents an integer from 1 to 5, Y 3 Same as the above definition. At least one of the group consisting of monomers represented by ).

[0803] The above Y 3 It is preferably -SO3M or -COOM, M is preferably H, metal atom, NR 7 4. Imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. 7 represents H or an organic group.

[0804] In the above formula (7a), the above n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less. 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of less likely to remain as an impurity and improving the heat resistance of the obtained molded article, H or NH 4 is preferred.

[0805] Examples of the perfluorovinylalkyl compound represented by the formula (7a) include CF2=CFCF2COOM (wherein M has the same meaning as defined above).

[0806] In the above formula (7b), from the perspective of the stability of the obtained aqueous dispersion, the above n2 is preferably an integer of 3 or less, and Y 3 From the viewpoint of obtaining appropriate water solubility and stability of the aqueous dispersion, -COOM is preferred, and from the viewpoint of less likely to remain as an impurity and improving the heat resistance of the obtained molded article, H or NH 4 is preferred.

[0807] The above-mentioned modified monomer preferably includes a modified monomer (A), preferably includes at least one selected from the group consisting of compounds represented by general formula (5a), general formula (5b), general formula (6a), general formula (6b), general formula (6c) and general formula (6d), and more preferably includes a compound represented by general formula (5a) or general formula (5b).

[0808] As the content of the above-mentioned modified monomer (A), it is preferably in the range of 0.00001 to 1.0 mass %. As the lower limit, it is more preferably 0.0001 mass %, further preferably 0.001 mass %, and further more preferably 0.005 mass %. As the upper limit, the preferred order is 0.90 mass %, 0.50 mass %, 0.40 mass %, 0.30 mass %, 0.20 mass %, 0.15 mass %, 0.10 mass %, 0.08 mass %, 0.05 mass %, and 0.01 mass %.

[0809] In the manufacture of the above-mentioned TFE polymer, the above-mentioned hydrocarbon surfactant can be used within the above-mentioned scope of use. The concentration of the above-mentioned hydrocarbon surfactant is not particularly limited as long as it is within the above-mentioned scope, and is usually added below the critical micelle concentration (CMC) at the beginning of polymerization. When the addition amount is large, needle-shaped particles with a large aspect ratio are generated, and the aqueous dispersion is gel-like and has impaired stability. The lower limit of the consumption of the above-mentioned hydrocarbon surfactant is preferably 0.0001 mass % relative to the aqueous medium, more preferably 0.001 mass %, further preferably 0.01 mass %, and particularly preferably 0.1 mass %. The upper limit of the consumption of the above-mentioned hydrocarbon surfactant is preferably 10 mass % relative to the aqueous medium, more preferably 5 mass %, further preferably 3 mass %, and particularly preferably 2 mass %.

[0810] The hydrocarbon surfactant may be added to the reaction vessel all at once before the start of polymerization, may be added all at once after the start of polymerization, may be added in several portions during polymerization, or may be added continuously during polymerization.

[0811] In the manufacture of the above-mentioned TFE polymer, as a polymerization initiator, organic peroxides such as persulfate (for example, ammonium persulfate), disuccinic acid peroxide, diglutaric acid peroxide, etc. can be used alone or in the form of their mixture. In addition, it is also possible to share with reducing agents such as sodium sulfite and use them as a redox system. In addition, it is also possible to add free radical scavengers such as hydroquinone and catechol during polymerization, or to add a decomposing agent of peroxides such as ammonium sulfite to adjust the free radical concentration in the system.

[0812] As the above-mentioned redox polymerization initiator, a redox initiator combining an oxidizing agent and a reducing agent is preferably used. As the oxidizing agent, persulfates, organic peroxides, potassium permanganate, manganese triacetate, ceric ammonium nitrate, etc. can be mentioned. As the reducing agent, sulfites, bisulfites, bromates, diimines, oxalic acid, etc. can be mentioned. As persulfates, ammonium persulfate and potassium persulfate can be mentioned. As sulfites, sodium sulfite and ammonium sulfite can be mentioned. In order to increase the decomposition rate of the initiator, it is also preferred to add copper salts and iron salts to the combination of redox initiators. As copper salts, copper (II) sulfate can be mentioned, and as iron salts, iron (II) sulfate can be mentioned.

[0813] Examples of the redox initiator include potassium permanganate / oxalic acid, ammonium persulfate / bisulfite / ferric sulfate, manganese triacetate / oxalic acid, ceric ammonium nitrate / oxalic acid, and bromate / bisulfite, with potassium permanganate / oxalic acid being preferred. When using a redox initiator, either the oxidizing agent or the reducing agent can be pre-placed in a polymerization tank, followed by continuous or intermittent addition of the other to initiate polymerization. For example, when using potassium permanganate / oxalic acid, oxalic acid is preferably placed in the polymerization tank and potassium permanganate is continuously added thereto.

[0814] In the production of the above-mentioned TFE polymer, a known chain transfer agent can be used as a chain transfer agent, for example, saturated hydrocarbons such as methane, ethane, propane, butane, halogenated hydrocarbons such as methyl chloride, dichloromethane, difluoroethane, alcohols such as methanol, ethanol, isopropyl alcohol, hydrogen, etc., preferably a chain transfer agent in a gaseous state at normal temperature and pressure.

[0815] The amount of the chain transfer agent used is usually 1 to 10,000 ppm, preferably 1 to 5,000 ppm, based on the total amount of TFE supplied.

[0816] During the production of the TFE polymer, a saturated hydrocarbon having 12 or more carbon atoms, which is substantially inert during the reaction and liquid under the aforementioned reaction conditions, may be used as a dispersion stabilizer in the reaction system at 2 to 10 parts by mass per 100 parts by mass of the aqueous medium. Furthermore, ammonium carbonate, ammonium phosphate, or the like may be added as a buffer to adjust the pH during the reaction.

[0817] Upon completion of the polymerization of the TFE polymer, an aqueous dispersion containing the TFE polymer having a solids concentration of 1.0 to 70% by mass and an average primary particle size of 50 to 500 nm can be obtained. The aqueous dispersion contains the hydrocarbon surfactant and the fluoropolymer. Furthermore, the use of the hydrocarbon surfactant can produce an aqueous dispersion of TFE polymer particles having a microparticle size of 0.5 μm or less.

[0818] The lower limit of the solid content concentration is preferably 5% by mass, more preferably 8% by mass. The upper limit is not particularly limited and may be 40% by mass or 35% by mass.

[0819] The lower limit of the average primary particle size is preferably 100 nm, more preferably 150 nm, and the upper limit is preferably 400 nm, more preferably 350 nm.

[0820] Fine powder can be produced by coagulating the aqueous dispersion of TFE polymer obtained by the production method of the present invention. After coagulation, washing, and drying, the aqueous dispersion of TFE polymer can be used as a fine powder in various applications. When coagulating the aqueous dispersion of TFE polymer, the aqueous dispersion obtained by polymerization, such as a polymer emulsion, is typically diluted with water to a polymer concentration of 5 to 20% by mass. The pH is adjusted to neutral or alkaline depending on the situation, and then stirred more vigorously than during the reaction in a container equipped with a stirrer. During the coagulation, stirring can be performed 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 flocculant. Alternatively, the coagulation can be performed continuously using a pipeline mixer or the like.

[0821] From the viewpoint of productivity, the concentration of the unagglomerated TFE polymer in the wastewater generated by the flocculation is preferably low, more preferably less than 0.4% by mass, and particularly preferably less than 0.3% by mass.

[0822] By adding pigments for coloring or various fillers for improving mechanical properties before or during the coagulation, a pigment-containing or filler-containing TFE polymer fine powder in which the pigment or filler is uniformly mixed can be obtained.

[0823] Drying of the wet powder obtained by coagulating an aqueous dispersion of TFE polymer is typically performed using vacuum, high-frequency, hot air, or other methods while maintaining the wet powder in a nearly immobile, preferably static, state. Friction between powders, especially at high temperatures, often adversely affects fine powders of TFE polymer. This is because particles composed of TFE polymer readily fibrillate even under minimal shear forces, losing their originally stable particle structure.

[0824] The drying is performed at a drying temperature of 10 to 300° C. (10 to 250° C.), preferably 100 to 300° C. (100 to 200° C.).

[0825] The obtained TFE polymer fine powder is preferably used for molding. Suitable applications include pipes for hydraulic systems and fuel systems in aircraft and automobiles, flexible hoses for reagents and steam, and wire coatings.

[0826] The aqueous dispersion of TFE polymer is preferably stabilized by adding a nonionic surfactant, further concentrated, and, depending on the intended purpose, an organic or inorganic filler added to form a composition for use in various applications. By coating such a composition onto a metal or ceramic substrate, it can be formed into a coating surface exhibiting non-stick properties, a low coefficient of friction, excellent gloss, smoothness, abrasion resistance, weather resistance, and heat resistance. This coating is suitable for coating rollers and cooking utensils, as well as impregnation of glass cloth.

[0827] Also can prepare the organosol of TFE polymer by the aqueous dispersion of TFE polymer.Above-mentioned organosol can comprise above-mentioned TFE polymer and organic solvent, as above-mentioned organic solvent, can enumerate ether solvent, ketone solvent, alcohol solvent, amide solvent, ester solvent, aliphatic hydrocarbon solvent, aromatic hydrocarbon solvent, halogenated hydrocarbon solvent, can preferably use N-methyl-2-pyrrolidone, dimethylacetamide etc.The preparation of above-mentioned organosol for example can be implemented by the method for putting down in writing in International Publication No. 2012 / 002038.

[0828] The aqueous dispersion of TFE polymer or the fine powder of TFE polymer obtained from the aqueous dispersion is also preferably used as a processing aid. When used as a processing aid, by mixing the aqueous dispersion or fine powder with a host polymer, etc., the melt strength of the host polymer during melt processing can be increased, thereby improving the mechanical strength, electrical properties, flame retardancy, anti-drip properties during combustion, and slip properties of the resulting polymer.

[0829] The aqueous dispersion of the TFE polymer or the fine powder of the TFE polymer is also preferably used as a binder for batteries or for dust prevention.

[0830] Furthermore, the aqueous dispersion of the TFE polymer or the fine powder of the TFE polymer is preferably compounded with a resin other than the TFE polymer and used as a processing aid. The aqueous dispersion or fine powder is suitable as a raw material for the PTFE described in, for example, Japanese Unexamined Patent Publication No. 11-49912, U.S. Patent No. 5,804,654, Japanese Unexamined Patent Publication No. 11-29679, and Japanese Unexamined Patent Publication No. 2003-2980. Processing aids using the aqueous dispersion or fine powder are comparable to those described in these publications.

[0831] The aqueous dispersion of the TFE polymer is preferably mixed with an aqueous dispersion of a melt-processable fluororesin and coagulated to form a co-coagulated powder. The co-coagulated powder is suitable as a processing aid.

[0832] Examples of the melt-processable fluororesin include FEP, PFA, TFE / perfluoroallyl ether copolymer, ETFE, and ethylene / TFE / HFP copolymer [EFEP]. Among them, FEP is preferred.

[0833] The non-fluorine-containing resin to be added as the co-coagulated powder may be in the form of powder, granules, or an emulsion. From the perspective of thoroughly mixing the resins, the addition is preferably performed while applying shear force by a known method such as extrusion kneading or roll kneading.

[0834] The aqueous dispersion preferably also contains the melt-processable fluororesin. Examples of such melt-processable fluororesins include FEP, PFA, TFE / perfluoroallyl ether copolymers, ETFE, and EFEP. The aqueous dispersion of the TFE polymer containing the melt-processable fluororesin can be used as a coating. The melt-processable fluororesin allows the TFE polymer particles to be fully bonded to each other, thereby improving film-forming properties and imparting a glossy finish to the resulting coating.

[0835] There are no particular limitations on the uses of the aqueous dispersion. Examples of uses in which the aqueous dispersion is directly applied include: coating by applying the dispersion onto a substrate, drying the dispersion, and then firing the dispersion as needed; impregnation by impregnating the dispersion into a porous support such as a non-woven fabric or a resin molded product, drying the dispersion, and preferably firing the dispersion; and casting by applying the dispersion onto a substrate such as glass, drying the dispersion, immersing the dispersion in water as needed, and peeling the dispersion to obtain a thin film. Examples of these applications include aqueous dispersion-type coatings, tent films, conveyor belts, printed circuit boards (CCLs), electrode binders, and electrode waterproofing agents.

[0836] The aqueous dispersion of the TFE polymer is also preferably used as a dust suppressant. This dust suppressant can be used in a method in which the TFE polymer is mixed with a dust-generating substance and the mixture is subjected to compression and shearing at a temperature of 20 to 200°C to fibrillate the TFE polymer and suppress dust from the dust-generating substance. Examples of such methods include those disclosed in Japanese Patent Nos. 2827152 and 2538783.

[0837] The aqueous dispersion of the TFE polymer can be suitably used in, for example, the dust suppression treatment composition described in International Publication No. 2007 / 004250 and the dust suppression treatment method described in International Publication No. 2007 / 000812.

[0838] The dust suppression agent is suitable for use in dust suppression in the fields of building materials, soil stabilization materials, solidification materials, fertilizers, filling and disposal of incineration ash and hazardous substances, explosion-proofing, cosmetics, and pet litter such as cat litter.

[0839] The aqueous dispersion of the TFE polymer is also preferably used as a raw material for obtaining TFE polymer fibers by the dispersion spinning method. The dispersion spinning method involves mixing the aqueous dispersion of the TFE polymer with an aqueous dispersion of a matrix polymer, extruding the mixture to form an intermediate fiber structure, and calcining the intermediate fiber structure to decompose the matrix polymer and sinter the TFE polymer particles to obtain TFE polymer fibers.

[0840] The above-mentioned surfactant can also be used to produce high molecular weight PTFE. That is, in the production method of the present invention using the above-mentioned surfactant, surprisingly, even without using the existing fluorinated surfactant, PTFE with a molecular weight equivalent to that of the production method using the existing fluorinated surfactant can be produced.

[0841] The high molecular weight PTFE powder obtained by polymerization has stretchability and non-melt processability, and is also useful as a raw material for stretched bodies (porous bodies).

[0842] When the stretching body is a film (PTFE stretched membrane or PTFE porous membrane), it is possible to stretch the film by a known PTFE stretching method. By stretching, the high molecular weight PTFE is easily fibrillated to form a PTFE porous body (film) composed of nodules and fibers.

[0843] Preferably, a sheet-shaped or rod-shaped paste extrudate is subjected to roll stretching in the extrusion direction, whereby a uniaxially stretched film can be obtained.

[0844] A biaxially stretched film can also be obtained by further stretching the film in the width direction using a tenter or the like.

[0845] It is also preferable to perform a semi-firing treatment before stretching.

[0846] The PTFE stretch body is a porous body with high porosity.

[0847] It can be suitably used as a filter medium for various precision filtration filters such as air filters and reagent filters, a support material for polymer electrolyte membranes, and the like.

[0848] Furthermore, it is also useful as a raw material for products used in the fields of fibers, medicine, electrochemistry, sealing materials, air filtration, ventilation / internal pressure regulation, liquid filtration, and general consumables.

[0849] The following examples illustrate specific uses.

[0850] Electrochemistry

[0851] Dielectric material prepreg, EMI shielding material, heat transfer material, etc. More specifically, there are printed circuit boards, electromagnetic shielding materials, insulating heat transfer materials, insulation materials, etc.

[0852] Sealing materials field

[0853] Gaskets, seals, pump diaphragms, pump tubes, sealing materials for aircraft, etc.

[0854] Air filtration field

[0855] ULPA filters (for semiconductor manufacturing), HEPA filters (for hospitals and semiconductor manufacturing), cylindrical cartridge filters (for industrial use), bag filters (for industrial use), heat-resistant bag filters (for exhaust gas treatment), heat-resistant pleated filters (for exhaust gas treatment), SINBRAN filters (for industrial use), catalytic filters (for exhaust gas treatment), filters with adsorbents (for HDD assembly), ventilation filters with adsorbents (for HDD assembly), ventilation filters (for HDD assembly, etc.), filters for vacuum cleaners (for vacuum cleaners), general-purpose multilayer felt materials, GT cartridge filters (for GT interchangeable products), cooling filters (for electronic equipment housings), etc.

[0856] Ventilation / internal pressure adjustment area

[0857] Freeze-drying materials such as freeze-drying containers, automotive ventilation materials suitable for electronic circuits and lamps, container applications such as container caps, protective ventilation applications for electronic devices including small terminals such as tablet terminals and mobile phone terminals, and medical ventilation applications.

[0858] Liquid filtration field

[0859] Semiconductor liquid filtration filters (for semiconductor manufacturing), hydrophilic PTFE filters (for semiconductor manufacturing), filters suitable for chemicals (for reagent processing), filters for pure water production lines (for pure water production), backwash type liquid filtration filters (for industrial wastewater treatment), etc.

[0860] General consumables field

[0861] Clothing, cable guide tubes (for removable wires on motorcycles), motorcycle clothing, cast pads (medical protective gear), vacuum cleaner filters, bagpipes (musical instruments), cables (such as signal cables for guitars), strings (for stringed instruments), etc.

[0862] Fiber field

[0863] PTFE fiber (fibrous material), sewing thread (fabric), knitting thread (fabric), rope, etc.

[0864] Medical field

[0865] Implants (stretchable products), artificial blood vessels, catheters, general surgery (tissue reinforcement materials), head and neck products (dura mater replacements), oral health (tissue regeneration medicine), plastic surgery (banding), etc.

[0866] Low molecular weight PTFE can also be produced using the above-mentioned surfactants.

[0867] Low-molecular-weight PTFE can be produced by polymerization, or by reducing the molecular weight of high-molecular-weight PTFE obtained by polymerization by a known method (thermal decomposition, radiation irradiation decomposition, etc.).

[0868] Low-molecular-weight PTFE (also known as PTFE fine powder) with a molecular weight of 600,000 or less has excellent chemical stability, extremely low surface energy, and is not prone to fibrillation. Therefore, it is suitable for the manufacture of plastics, inks, cosmetics, coatings, greases, office automation equipment parts, toners, etc. as an additive for the purpose of improving slip properties and the texture of the coating surface (see, for example, Japanese Patent Application Laid-Open No. 10-147617).

[0869] Alternatively, a polymerization initiator and the above-mentioned surfactant may be dispersed in an aqueous medium in the presence of a chain transfer agent, and TFE may be polymerized or a monomer copolymerizable with TFE and TFE may be polymerized to obtain low molecular weight PTFE.

[0870] When the low-molecular-weight PTFE obtained by the above-mentioned polymerization is used as a powder, the powder particles can be prepared by coagulating the above-mentioned aqueous dispersion.

[0871] In the present invention, high molecular weight PTFE refers to PTFE that is not melt-processable and fibrillable. On the other hand, low molecular weight PTFE refers to PTFE that is melt-processable and not fibrillable.

[0872] The non-melt processability mentioned above refers to the property that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point according to ASTM D 1238 and D 2116.

[0873] The presence or absence of fibrillation can be determined by "paste extrusion," a typical method for molding "high molecular weight PTFE powder," a powder made from a TFE polymer. Generally, paste extrusion is possible because high molecular weight PTFE exhibits fibrillation. If the unfired molded article obtained by paste extrusion lacks substantial strength or elongation, for example, if the elongation is 0% and the article breaks when stretched, it can be considered to lack fibrillation.

[0874] The standard specific gravity (SSG) of the high molecular weight PTFE is preferably 2.130 to 2.280. The standard specific gravity is measured using a sample molded according to ASTM D 4895-89 using the water displacement method according to ASTM D 792. In the present invention, "high molecular weight" means that the standard specific gravity is within the above range.

[0875] The complex viscosity of the low molecular weight PTFE at 380°C is 1×10 2 ~7×10 5 Pa·s. In the present invention, "low molecular weight" means that the complex viscosity is within the above range.

[0876] The complex viscosity of above-mentioned high molecular weight PTFE is extremely high compared with above-mentioned low molecular weight PTFE, is difficult to measure its complex viscosity accurately.On the other hand, the complex viscosity of above-mentioned low molecular weight PTFE can be measured, but is difficult to obtain the molded products that can be used for standard specific gravity measurement by above-mentioned low molecular weight PTFE, is difficult to measure its standard specific gravity accurately.Therefore, among the present invention, as the index of the molecular weight of above-mentioned high molecular weight PTFE, adopt standard specific gravity, as the index of the molecular weight of above-mentioned low molecular weight PTFE, adopt complex viscosity.It should be noted that, for any one in above-mentioned high molecular weight PTFE and above-mentioned low molecular weight PTFE, the assay method that can directly determine molecular weight is all unknown.

[0877] The peak temperature of the high molecular weight PTFE is preferably 333 to 347°C, more preferably 335 to 345°C. The peak temperature of the low molecular weight PTFE is preferably 322 to 333°C, more preferably 324 to 332°C. The peak temperature is the temperature corresponding to the maximum value in the heat of fusion curve of PTFE that has no history of being heated to a temperature of 300°C or higher, when the temperature is increased at a rate of 10°C / minute using a differential scanning calorimeter [DSC]. Alternatively, the peak temperature can be determined as the temperature corresponding to the maximum value that appears in a differential thermal (DTA) curve obtained by increasing the temperature of PTFE that has no history of being heated to a temperature of 300°C or higher at a rate of 10°C / minute using a TG / DTA (differential thermogravimetric analysis) apparatus.

[0878] The high molecular weight PTFE preferably exhibits at least one endothermic peak in the range of 333 to 347°C in a heat of fusion curve when the temperature is increased at a rate of 10°C / minute using a differential scanning calorimeter [DSC] on PTFE that has no history of being heated to a temperature of 300°C or higher, and the heat of fusion at 290 to 350°C calculated from the heat of fusion curve is preferably 62 mJ / mg or higher.

[0879] An unfired tape (green tape) can also be obtained from the PTFE fine powder obtained using the above-mentioned surfactant.

[0880] The above-mentioned surfactant, the decomposition products or by-products of the above-mentioned surfactant by-products, residual monomers, etc. can be recovered from the waste water generated by the above-mentioned coagulation or cleaning, and / or the waste gas generated by the drying process and refined, thereby the above-mentioned surfactant, the decomposition products or by-products of the above-mentioned surfactant by-products, residual monomers, etc. are reused. There is no particular limitation on the method for carrying out the above-mentioned recovery and purification, and it can be carried out by known methods. For example, it can be implemented by the method described in Japanese Patent Application Laid-Open No. 2011-520020.

[0881] (II) Melt-processable fluororesins

[0882] (1) In the production method of the present invention, the polymerization of FEP is preferably carried out at a polymerization temperature of 10 to 150° C. and a polymerization pressure of 0.3 to 6.0 MPaG.

[0883] The preferred monomer composition (mass %) of FEP is TFE:HFP = (60-98):(2-40), more preferably (60-95):(5-40), and even more preferably (85-92):(8-15). Furthermore, the FEP may be modified by further using a perfluoro(alkyl vinyl ether) as a third component in an amount within the range of 0.1-2 mass % of the total monomers.

[0884] In the polymerization of FEP, the surfactant can be used within the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 10% by mass relative to 100% by mass of the aqueous medium.

[0885] In the polymerization of FEP, preferably used chain transfer agents include cyclohexane, methanol, ethanol, propanol, ethane, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, and methyl chloride. Preferably used pH buffers include ammonium carbonate and disodium hydrogen phosphate.

[0886] The aqueous FEP dispersion obtained by the production method of the present invention can be subjected to post-treatment such as concentration, if necessary, followed by drying to form a powder, and then melt-extruded to form pellets. The aqueous medium in the aqueous FEP dispersion may contain additives such as nonionic surfactants, and may or may not contain a water-soluble organic solvent such as a water-soluble alcohol, as needed.

[0887] Melt extrusion may be carried out under any extrusion conditions that allow pellets to be generally produced, and the extrusion conditions may be appropriately set.

[0888] In the production method of the present invention, the obtained FEP may have terminal groups such as -CF3 and -CF2H at at least one of the polymer main chain and the polymer side chain, but it is preferred that the content of thermally unstable groups such as -COOH, -CH2OH, -COF, -CF=CF-, -CONH2, and -COOCH3 (hereinafter referred to as "unstable terminal groups") is low or absent.

[0889] Since the unstable terminal groups are chemically unstable, they not only reduce the heat resistance of the resin but also increase the attenuation of the resulting electric wire.

[0890] In the production method of the present invention, it is preferred that the total number of unstable terminal groups and -CF2H terminal groups is less than 1×10 6 The polymer at the time of polymerization termination is produced in such a way that the number of carbon atoms is 50 or less. More preferably, 6 The number of carbon atoms is less than 20, more preferably less than 5. The unstable terminal groups and -CF2H terminal groups may not exist, and all the terminal groups may be -CF3 terminal groups.

[0891] Unstable terminal groups and -CF2H terminal groups can be converted into -CF3 terminal groups by fluorination treatment to stabilize them. The fluorination treatment method is not particularly limited, and a method of exposing the polymer to a fluorine radical source that generates fluorine radicals under fluorination treatment conditions can be mentioned. As the above-mentioned fluorine radical source, fluorine gas, CoF3, AgF2, UF6, OF2, N2F2, CF3OF and halogen fluoride (such as IF5, ClF3) can be mentioned. Among them, a method of directly contacting the fluorinated gas with the FEP obtained by the manufacturing method of the present invention is preferred. From the perspective of reaction control, the above-mentioned contact is preferably carried out using diluted fluorine gas with a fluorine gas concentration of 10 to 50% by mass. The above-mentioned diluted fluorine gas can be obtained by diluting the fluorine gas with an inert gas such as nitrogen and argon. The above-mentioned fluorine gas treatment can be carried out at a temperature of 100 to 250°C, for example. It should be noted that the treatment temperature is not limited to the above-mentioned range and can be appropriately set according to the situation. The above-mentioned fluorine gas treatment is preferably carried out by continuously or intermittently supplying diluted fluorine gas into the reactor. The fluorination treatment can be performed on either the dry powder after polymerization or the pellets obtained by melt extrusion.

[0892] The FEP obtained by the production method of the present invention has good moldability and is less likely to produce molding defects. It also has excellent heat resistance, chemical resistance, solvent resistance, insulation, electrical properties, etc.

[0893] The method for producing the FEP powder is a method for obtaining the powder by drying the aqueous fluoropolymer dispersion containing FEP obtained by the production method of the present invention and pulverizing the dispersion.

[0894] The powder may be fluorinated. The method for producing the fluorinated powder is a method for producing the fluorinated powder by supplying fluorine gas to the powder obtained by the method for producing the powder to fluorinate the powder.

[0895] The method for producing the FEP pellets is a method for obtaining pellets by pelletizing the FEP obtained by the production method of the present invention.

[0896] The pellets may be fluorinated. The method for producing the fluorinated pellets is a method for producing the fluorinated pellets by supplying fluorine gas to the pellets obtained by the method for producing the pellets to fluorinate them.

[0897] Therefore, this FEP can be used in the production of various molded products such as covering materials for electric wires, foamed electric wires, cables, and conductive wires, as well as tubes, films, sheets, and filaments.

[0898] (2) In the production method of the present invention, the polymerization of TFE / perfluoro(alkyl vinyl ether) copolymers such as PFA and MFA and TFE / perfluoroallyl ether copolymers is preferably carried out at a polymerization temperature of 10 to 100° C. and a polymerization pressure of 0.3 to 6.0 MPaG.

[0899] The preferred monomer composition (mol %) of the TFE / perfluoro(alkyl vinyl ether) copolymer is TFE:perfluoro(alkyl vinyl ether)=(90-99.7):(0.3-10), more preferably (97-99):(1-3). As the perfluoro(alkyl vinyl ether), preferably used is a monomer of the formula: CF2=CFORf 4 (Where Rf 4 A substance represented by a perfluoroalkyl group having 1 to 6 carbon atoms).

[0900] The preferred monomer composition (mol %) of the TFE / perfluoroallyl ether copolymer is TFE:perfluoroallyl ether = (90-99.7): (0.3-10), more preferably (97-99): (1-3). As the perfluoroallyl ether, preferably used is a compound of the formula: CF2=CFCF2ORf 4 (Where Rf 4 A substance represented by a perfluoroalkyl group having 1 to 6 carbon atoms).

[0901] In the polymerization of the TFE / perfluoro(alkyl vinyl ether) copolymer and the TFE / perfluoroallyl ether copolymer, the surfactant can be used within the range of use in the production method of the present invention, and is generally preferably added in an amount of 0.0001 to 10% by mass relative to 100% by mass of the aqueous medium.

[0902] In the polymerization of the above-mentioned TFE / perfluoro(alkyl vinyl ether) copolymer and TFE / perfluoroallyl ether copolymer, cyclohexane, methanol, ethanol, propanol, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, chloromethane, methane, ethane, etc. are preferably used as chain transfer agents, and ammonium carbonate, disodium hydrogen phosphate, etc. are preferably used as pH buffers.

[0903] The aqueous dispersion of TFE / perfluoro(alkyl vinyl ether) copolymers and TFE / perfluoroallyl ether copolymers such as PFA and MFA obtained by the production method of the present invention can be subjected to post-treatment such as concentration, dried, and powdered, and then melt-extruded to form pellets. The aqueous medium in the aqueous dispersion can contain additives such as nonionic surfactants and water-soluble organic solvents such as water-soluble alcohols, or can be free of water-soluble organic solvents.

[0904] Melt extrusion may be carried out under any extrusion conditions that allow pellets to be generally produced, and the extrusion conditions may be appropriately set.

[0905] The copolymer is preferably subjected to a fluorine gas treatment in order to improve its heat resistance and further enhance the effect of suppressing chemical permeation of the molded article.

[0906] The fluorine treatment is carried out by bringing fluorine gas into contact with a reagent permeation inhibitor. However, since the reaction with fluorine is very exothermic, it is preferred to dilute the fluorine with an inert gas such as nitrogen. The amount of fluorine in the fluorine / inert gas mixture is 1 to 100% by weight, preferably 10 to 25% by weight. The treatment temperature is 150 to 250°C, preferably 200 to 250°C, and the fluorine treatment time is 3 to 16 hours, preferably 4 to 12 hours. The gas pressure of the fluorine treatment is in the range of 1 to 10 atmospheres, preferably atmospheric pressure. When using a reactor at atmospheric pressure, the fluorine / inert gas mixture can be passed continuously into the reactor. As a result, the unstable ends of the above-mentioned copolymer are converted into -CF3 ends, which are thermally stable.

[0907] As a molding method for the above-mentioned copolymer and its composition, molding methods such as compression molding, transfer molding, extrusion molding, injection molding, and blow molding can be applied in the same manner as conventional PFA.

[0908] The desired molded products can be obtained by such a molding method. Examples of molded products include sheets, films, gaskets, round rods, square rods, tube blanks, tubes, round grooves, square grooves, tanks, chip carriers, chip boxes, beakers, filter housings, flow meters, pumps, valves, stopcocks, connectors, nuts, wires, heat-resistant wires, etc.

[0909] Among these, they can be particularly suitably used for tubes, tube blanks, tanks, connectors, and the like used in various chemical reaction apparatuses, semiconductor manufacturing apparatuses, and acidic or alkaline reagent supply apparatuses that require reagent impermeability.

[0910] A primer composition can be obtained by adding a nonionic surfactant to an aqueous dispersion of a TFE / perfluoro(alkyl vinyl ether) copolymer or a TFE / perfluoroallyl ether copolymer, such as PFA or MFA, and dissolving or dispersing polyethersulfone, polyamideimide, and / or polyimide, as well as metal powder, in an organic solvent, as needed. This composition can also be used in a method for coating a metal surface with a fluororesin, comprising applying the primer composition to the metal surface, applying a melt-processable fluororesin composition onto the thus formed primer layer, and then firing the melt-processable fluororesin composition layer together with the primer layer.

[0911] (3) In the production method of the present invention, the polymerization of ETFE is preferably carried out at a polymerization temperature of 10 to 100° C. and a polymerization pressure of 0.3 to 2.0 MPaG.

[0912] The preferred monomer composition (mol %) of ETFE is TFE:ethylene = (50-99): (50-1). Furthermore, as the above-mentioned ETFE, a third monomer may be further used and modified within the range of 0-20 mass % of the total monomers. Preferably, TFE:ethylene:third monomer = (63-94): (27-2): (1-10). Preferred third monomers include perfluorobutylethylene, perfluorohexylethylene, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octene, 2,3,3,4,4,5,5-heptafluoro-1-pentene (CH2=CFCF2CF2CF2H), and 2-trifluoromethyl-3,3,3-trifluoropropylene ((CF3)2C=CH2).

[0913] In the polymerization of ETFE, the surfactant can be used within the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 10% by mass relative to 100% by mass of the aqueous medium.

[0914] In the polymerization of ETFE, preferably used as a chain transfer agent are cyclohexane, methanol, ethanol, propanol, ethane, propane, butane, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, methyl chloride, and the like.

[0915] The aqueous dispersion of ETFE obtained by the manufacture method of the present invention may be concentrated as required, dried, powdered, and then melt-extruded to form pellets. The aqueous medium in the aqueous dispersion may contain additives such as nonionic surfactants as required, may contain water-soluble organic solvents such as water-soluble alcohols, or may not contain water-soluble organic solvents.

[0916] Melt extrusion may be carried out under any extrusion conditions that allow pellets to be generally produced, and the extrusion conditions may be appropriately set.

[0917] The sheet of above-mentioned ETFE can be made into sheet by extrusion molding.That is, ETFE powder or pellet can be melted, extruded continuously by a die, and obtained the flaky molded product after the cooling.Additives can be added in the ETFE.

[0918] As additives, known additives can be used appropriately. As specific examples, ultraviolet light absorbers, light stabilizers, antioxidants, infrared absorbers, flame retardants, flame retardant fillers, organic pigments, inorganic pigments, dyes, etc. can be mentioned. From the aspect of excellent weather resistance, inorganic additives are preferred.

[0919] The content of the additive in the ETFE sheet is preferably 20% by mass or less, particularly preferably 10% by mass or less, based on the total mass of the ETFE sheet.

[0920] The ETFE sheet has excellent mechanical strength and appearance and is therefore suitable as a membrane material (roofing material, ceiling material, exterior wall material, interior wall material, covering material, etc.) for membrane structure buildings (sports facilities, gardening facilities, atriums, etc.).

[0921] In addition, membrane materials are not only useful in membrane structure buildings, but are also useful in the following materials, for example: outdoor panels (soundproof walls, wind fences, wave-breaking fences, garage roofs, shopping malls, pedestrian street side walls, roofing materials), glass scattering prevention films, heat-resistant and water-resistant sheets, building materials, etc. (tent materials for tent warehouses, sunshade membrane materials, partial roofing materials for lighting, window materials instead of glass, fire-proof membrane materials, curtains, outer wall reinforcement, waterproof membranes, smoke-proof membranes, flame-retardant transparent partitions, road reinforcement, interior decoration (lighting, wall surfaces, blinds, etc.), exterior decoration (curtains, signs, etc.)), life and leisure products (fishing rods, rackets, golf clubs, screens, etc.), automotive materials (hoods, damping materials, car bodies, etc.), aircraft materials, ship materials, home appliance exteriors, storage tanks, container inner walls, filters, construction membrane materials, electronic materials (printed circuit boards, wiring circuit boards, insulating films, anti-sticking films, etc.), surface materials for solar cell modules, reflector protection materials for solar power generation, surface materials for solar water heaters, etc.

[0922] (4) The production method of the present invention can also be used to produce an electrolyte polymer precursor. In the production method of the present invention, the polymerization of the electrolyte polymer precursor is preferably carried out at a polymerization temperature of 10 to 100°C and a polymerization pressure of 0.1 to 2.0 MPaG. The electrolyte polymer precursor is a substance comprising a vinyl ether monomer as shown below, which can be converted into an ion exchange polymer by hydrolysis.

[0923] Examples of the vinyl ether monomer used in the electrolyte polymer precursor include:

[0924] General formula (150): CF2=CF-O-(CF2CFY 151 -O) n -(CFY 152 ) m -A 151

[0925] (where Y 151 represents a fluorine atom, a chlorine atom, a -SO2F group or a perfluoroalkyl group. The perfluoroalkyl group may contain an ethereal oxygen and a -SO2F group. n represents an integer from 0 to 3. n Y 151 Can be the same or different. 152 represents a fluorine atom, a chlorine atom or a -SO2F group. m represents an integer from 1 to 5. m Y 152 Can be the same or different. 151 Indicates -SO2X 151、-COZ 151 or-POZ 152 Z 153 .X 151 Indicates F, Cl, Br, I, -OR 151 or -NR 152 R 153 . Z 151 、Z 152 and Z 153 Identical or different representation -NR 154 R 155 OR 156 . R 151 、R 152 、R 153 、R 154 、R 155 and R 156 The fluorine monomer represented by (a) is represented by (i) hydrogen, ammonium, an alkali metal, an alkyl group which may contain a fluorine atom, an aryl group, or a sulfonyl group. The preferred monomer composition (mol %) of the electrolyte polymer precursor is TFE:vinyl ether = (50-99): (50-1), more preferably TFE:vinyl ether = (50-93): (50-7).

[0926] The electrolyte polymer precursor may be modified with a third monomer in an amount of 0 to 20% by mass of the total monomers. Examples of the third monomer include polyfunctional monomers such as CTFE, vinylidene fluoride, perfluoroalkyl vinyl ether, and divinylbenzene.

[0927] The electrolyte polymer precursor thus obtained can be formed into a film, and then subjected to hydrolysis with an alkaline solution and treatment with an inorganic acid, and then used as a polymer electrolyte membrane for fuel cells, electrolysis devices, redox flow batteries, and the like.

[0928] Alternatively, an electrolyte polymer dispersion can be obtained by performing hydrolysis with an alkaline solution while maintaining the dispersed state of the electrolyte polymer precursor.

[0929] Next, the mixture is heated to 120° C. or higher in a pressurized container and dissolved in, for example, a water / alcohol mixed solvent to form a solution.

[0930] The solution thus obtained can be used as, for example, a binder for an electrode, or can be compounded with various additives and cast into a film for use in, for example, antifouling coatings, organic actuators, and the like.

[0931] (5) TFE / VDF copolymer

[0932] In the production method of the present invention, the polymerization temperature of the TFE / VDF copolymer is not particularly limited and may be 0 to 100° C. The polymerization pressure is appropriately set depending on other polymerization conditions such as the polymerization temperature and may generally be 0 to 9.8 MPaG.

[0933] The preferred monomer composition (mol %) of the TFE / VDF copolymer is TFE:VDF = (5-90):(95-10). Furthermore, the TFE / VDF copolymer may be modified by further using a third monomer in a range of 0-50 mol % of the total monomers. The preferred ratio is TFE:ethylene:third monomer = (30-85):(10-69.9):(0.1-10).

[0934] As the third monomer, preferably

[0935] Formula: CX 11 X 12 =CX 13 (CX 14 X 15 ) n11 X 16

[0936] (Where X 11 ~X 16 The same or different represent H, F or Cl, and n11 represents an integer from 0 to 8. TFE and VDF are not included. ) represented by the monomer, or

[0937] Formula: CX 21 X 22 =CX 23 -O(CX 24 X 25 ) n21 X 26

[0938] (Where X 21 ~X 26 The monomers are the same or different and represent H, F or Cl, and n21 represents an integer from 0 to 8.

[0939] In addition, the third monomer may be a non-fluorinated ethylenic monomer. From the perspective of maintaining heat resistance and chemical resistance, the non-fluorinated ethylenic monomer is preferably selected from ethylenic monomers having a carbon number of 6 or less. For example, ethylene, propylene, 1-butene, 2-butene, vinyl chloride, vinylidene chloride, alkyl vinyl ether (methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, etc.), maleic acid, itaconic acid, 3-butenoic acid, 4-pentenoic acid, vinylsulfonic acid, acrylic acid, methacrylic acid, etc. may be mentioned.

[0940] In the polymerization of the TFE / VDF copolymer, the above-mentioned surfactant can be used within the range used in the production method of the present invention, and is usually added in an amount of 0.0001 to 5% by mass relative to 100% by mass of the aqueous medium.

[0941] The amidation treatment can be carried out by contacting the TFE / VDF copolymer obtained by polymerization with aqueous ammonia, ammonia gas, or a nitrogen compound capable of generating ammonia.

[0942] The TFE / VDF copolymer obtained by the above method is also preferably used as a raw material for obtaining TFE / VDF copolymer fibers by a spinning and drawing method. The spinning and drawing method is a method in which the TFE / VDF copolymer is melt-spun, cooled, and solidified to obtain undrawn yarns, which are then drawn by running the undrawn yarns through a heated cylinder to obtain TFE / VDF copolymer fibers.

[0943] Alternatively, the TFE / VDF copolymer can be dissolved in an organic solvent to obtain a solution of the TFE / VDF copolymer. Examples of such organic solvents include nitrogen-containing organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and dimethylformamide; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as tetrahydrofuran and dioxane; and mixtures thereof, including low-boiling-point general-purpose organic solvents. This solution can be used as a binder for batteries.

[0944] The aqueous dispersion of the TFE / VDF copolymer is preferably applied on a porous substrate composed of a polyolefin resin to form a composite porous membrane for use. Inorganic particles and / or organic particles are preferably dispersed in an aqueous dispersion, applied on a porous substrate to form a composite porous membrane for use. The composite porous membrane thus obtained can be used as a separator for lithium secondary batteries, etc.

[0945] The melt-processable fluororesin powder described above is suitable for use as a powder coating. When applied to a substrate, a powder coating composed of the melt-processable fluororesin powder can produce a smooth coating. Melt-processable fluororesin powders with an average particle size of 1 μm or greater and less than 100 μm are particularly suitable for use in electrostatic coating, while those with an average particle size of 100 μm or greater and less than 1000 μm are particularly suitable for use in spin coating or rotational molding.

[0946] The melt-processable fluororesin powder can be produced by drying the melt-processable fluororesin aqueous dispersion obtained by the production method of the present invention to obtain a powder. The production method for producing the melt-processable fluororesin powder is also one of the present invention.

[0947] (III) Fluororubber

[0948] In the production method of the present invention, the polymerization of the fluororubber is performed by introducing pure water and the surfactant into a pressure-resistant reaction vessel equipped with a stirrer. After deoxygenation, monomers are added, the temperature is adjusted to a predetermined value, and a polymerization initiator is added to initiate the reaction. Because the pressure decreases as the reaction proceeds, additional monomers are supplied continuously or intermittently to maintain the initial pressure. When the predetermined amount of monomer has been supplied, the supply is stopped, the monomers in the reaction vessel are purged, the temperature is returned to room temperature, and the reaction is terminated. In this manner, the polymer emulsion can be continuously removed from the reaction vessel.

[0949] In particular, when producing a thermoplastic elastomer as the above-mentioned fluororubber, as disclosed in International Publication No. 00 / 01741, the following method can also be used: fluoropolymer microparticles are first synthesized at the higher concentration mentioned above, and then further polymerized after dilution. This can accelerate the final polymerization rate compared to conventional polymerization.

[0950] The polymerization of the fluororubber is carried out under appropriate conditions selected from the perspectives of the physical properties of the target polymer and polymerization rate control, with the polymerization temperature generally being -20 to 200°C, preferably 5 to 150°C, and the polymerization pressure generally being 0.5 to 10 MPaG, preferably 1 to 7 MPaG. The pH of the polymerization medium is preferably maintained at a range of generally 2.5 to 13 using a pH adjuster, as described below, or the like, by known methods.

[0951] As the monomer used in the polymerization of the above-mentioned fluororubber, in addition to vinylidene fluoride, fluorine-containing ethylenically unsaturated monomers having at least the same number of fluorine atoms as carbon atoms and copolymerizable with vinylidene fluoride can also be mentioned. As the above-mentioned fluorine-containing ethylenically unsaturated monomers, trifluoropropylene, pentafluoropropylene, hexafluorobutene, and octafluorobutene can be mentioned. Among them, hexafluoropropylene is particularly preferred due to the properties of the elastomer obtained when it blocks the crystal growth of the polymer. In addition, as the above-mentioned fluorine-containing ethylenically unsaturated monomers, trifluoroethylene, TFE and CTFE can also be mentioned. It is also possible to use one or more fluorine-containing monomers with chlorine and / or bromine substituents. Perfluoro (alkyl vinyl ether), for example perfluoro (methyl vinyl ether) can also be used. TFE and HFP are preferred in the manufacture of fluororubber.

[0952] The preferred monomer composition (mass %) of the fluororubber is vinylidene fluoride:HFP:TFE=(20-70):(30-48):(0-32). Fluororubber with this composition exhibits excellent elastomeric properties, chemical resistance, and thermal stability.

[0953] During the polymerization of the fluororubber, the surfactant may be used within the range of use in the production method of the present invention, and is generally added in an amount of 0.0001 to 20% by mass relative to 100% by mass of the aqueous medium, preferably 10% by mass or less, and more preferably 2% by mass or less.

[0954] In the polymerization of the above-mentioned fluororubber, as a polymerization initiator, a known inorganic free radical polymerization initiator can be used. As the above-mentioned inorganic free radical polymerization initiator, existing known water-soluble inorganic peroxides, such as persulfates, perphosphates, perborate, percarbonate or permanganate of sodium, potassium and ammonium are particularly useful. The above-mentioned free radical polymerization initiator can also utilize a reducing agent (such as sulfite, bisulfite, pyrosulfite, hyposulfite, thiosulfate, phosphite or hypophosphite of sodium, potassium or ammonium) or utilize an easily oxidized metal compound (such as ferrous salt, cuprous salt or silver salt) to further activate. The preferred inorganic free radical polymerization initiator is ammonium persulfate, and more preferably ammonium persulfate and sodium bisulfite are used simultaneously in a redox system.

[0955] The added concentration of the polymerization initiator is appropriately determined depending on the molecular weight of the target fluoropolymer and the polymerization reaction rate, and is set to 0.0001 to 10% by mass, preferably 0.01 to 5% by mass, based on 100% by mass of the total monomer amount.

[0956] In the polymerization of the fluororubber, a known chain transfer agent can be used, and hydrocarbons, esters, ethers, alcohols, ketones, chlorides, carbonates, etc. can be used. For thermoplastic elastomers, hydrocarbons, esters, ethers, alcohols, chlorides, iodides, etc. can be used. Among them, acetone and isopropyl alcohol are preferred. In the polymerization of thermoplastic elastomers, isopentane, diethyl malonate, and ethyl acetate are preferred because they do not easily reduce the reaction rate. Diiodide compounds such as I(CF2)4I, I(CF2)6I, and ICH2I are preferred because they can iodinate the polymer terminals and can be used as reactive polymers.

[0957] The amount of the chain transfer agent used is preferably 0.5×10 -3 ~5×10 -3 mol%, preferably 1.0×10 -3 ~3.5×10 -3 mol%.

[0958] In the polymerization of the fluororubber, paraffin wax or the like can be preferably used as an emulsion stabilizer, and in the polymerization of the thermoplastic elastomer, phosphate, sodium hydroxide, potassium hydroxide or the like can be preferably used as a pH adjuster.

[0959] The aqueous dispersion containing fluororubber obtained by the production method of the present invention has a solid content concentration of 1.0 to 40% by mass at the time of polymerization completion, an average particle size of 0.03 to 1 μm, preferably 0.05 to 0.5 μm, and a number average molecular weight of 1,000 to 2,000,000.

[0960] The aqueous dispersion of fluororubber obtained by the production method of the present invention can be made into a dispersion suitable for rubber molding by adding a dispersion stabilizer such as a hydrocarbon surfactant and concentrating the dispersion as needed. The above dispersion is subjected to treatments such as pH adjustment, coagulation, and heating. Each treatment is performed as follows.

[0961] The pH adjustment includes adding an inorganic acid such as nitric acid, sulfuric acid, hydrochloric acid or phosphoric acid, and / or a carboxylic acid having 5 or less carbon atoms and a pKa of 4.2 or less to adjust the pH to 2 or less.

[0962] The coagulation is performed by adding an alkaline earth metal salt. Examples of the alkaline earth metal salt include nitrates, chlorates, and acetates of calcium or magnesium.

[0963] Either the pH adjustment or the coagulation may be performed first, but the pH adjustment is preferably performed first.

[0964] After each operation, rinse with water equal to the volume of the fluororubber to remove any impurities such as buffer and salts present in the fluororubber, and then dry. Drying is usually performed in a drying oven at a high temperature of approximately 70-200°C while circulating air.

[0965] The fluororubber may be a partially fluorinated rubber or a perfluororubber.

[0966] Examples of partially fluorinated rubbers include vinylidene fluoride (VdF)-based fluororubbers, tetrafluoroethylene (TFE) / propylene (Pr)-based fluororubbers, tetrafluoroethylene (TFE) / propylene / vinylidene fluoride (VdF)-based fluororubbers, ethylene / hexafluoropropylene (HFP)-based fluororubbers, ethylene / hexafluoropropylene (HFP) / vinylidene fluoride (VdF)-based fluororubbers, and ethylene / hexafluoropropylene (HFP) / tetrafluoroethylene (TFE)-based fluororubbers. Among these, at least one selected from the group consisting of vinylidene fluoride-based fluororubbers and tetrafluoroethylene / propylene-based fluororubbers is preferred.

[0967] The vinylidene fluoride-based fluororubber is preferably a copolymer composed of 45 to 85 mol% of vinylidene fluoride and 55 to 15 mol% of at least one other monomer copolymerizable with vinylidene fluoride. More preferably, it is a copolymer composed of 50 to 80 mol% of vinylidene fluoride and 50 to 20 mol% of at least one other monomer copolymerizable with vinylidene fluoride.

[0968] Examples of the at least one other monomer copolymerizable with vinylidene fluoride include tetrafluoroethylene [TFE], hexafluoropropylene [HFP], fluoroalkyl vinyl ether, chlorotrifluoroethylene [CTFE], trifluoroethylene, trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, vinyl fluoride, and the general formula (100): CH2=CFRf 101 (Where Rf 101 A fluorinated monomer represented by a linear or branched fluoroalkyl group having 1 to 12 carbon atoms, general formula (170): CH2=CH-(CF2) n -X 171 (Where X 171 is H or F, and n is an integer from 3 to 10. ) fluorinated monomers, monomers providing crosslinking sites, and non-fluorinated monomers such as ethylene, propylene, and alkyl vinyl ether. These can be used alone or in any combination. Among these, at least one selected from the group consisting of TFE, HFP, fluoroalkyl vinyl ether, and CTFE is preferably used. As the fluoroalkyl vinyl ether, a fluorinated monomer represented by general formula (160) is preferred.

[0969] Specific examples of vinylidene fluoride-based fluororubbers include VdF / HFP rubber, VdF / HFP / TFE rubber, VdF / CTFE rubber, VdF / CTFE / TFE rubber, VDF / fluorine monomer rubber represented by general formula (100), VDF / fluorine monomer / TFE rubber represented by general formula (100), VDF / perfluoro(methyl vinyl ether) [PMVE] rubber, VDF / PMVE / TFE rubber, and VDF / PMVE / TFE / HFP rubber. Preferred examples of the VDF / fluorine monomer rubber represented by general formula (100) include VDF / CH2=CFCF3 rubber, and preferred examples of the VDF / fluorine monomer / TFE rubber represented by general formula (100) include VDF / TFE / CH2=CFCF3 rubber.

[0970] The VDF / CH2=CFCF3-based rubber is preferably a copolymer composed of 40 to 99.5 mol% of VDF and 0.5 to 60 mol% of CH2=CFCF3, and more preferably a copolymer composed of 50 to 85 mol% of VDF and 20 to 50 mol% of CH2=CFCF3.

[0971] The tetrafluoroethylene / propylene fluororubber is preferably a copolymer composed of 45 to 70 mol% of tetrafluoroethylene, 55 to 30 mol% of propylene, and 0 to 5 mol% of a fluorine monomer providing a crosslinking site.

[0972] The fluororubber may be a perfluororubber. The perfluororubber is preferably a perfluororubber containing TFE, for example, at least one selected from the group consisting of a copolymer of TFE / a fluoromonomer represented by the general formula (160), (130), or (140) and a copolymer of TFE / a fluoromonomer represented by the general formula (160), (130), or (140) / a monomer providing a crosslinking site.

[0973] Regarding the composition, in the case of a TFE / PMVE copolymer, it is preferably 45 to 90 / 10 to 55 (mol %), more preferably 55 to 80 / 20 to 45, and even more preferably 55 to 70 / 30 to 45.

[0974] In the case of a copolymer of TFE / PMVE / a monomer providing a crosslinking site, the ratio is preferably 45-89.9 / 10-54.9 / 0.01-4 (mol %), more preferably 55-77.9 / 20-49.9 / 0.1-3.5, and even more preferably 55-69.8 / 30-44.8 / 0.2-3.

[0975] In the case of a TFE / fluorine monomer copolymer represented by the general formula (160), (130) or (140) having 4 to 12 carbon atoms, the ratio is preferably 50 to 90 / 10 to 50 (mol %), more preferably 60 to 88 / 12 to 40, and further preferably 65 to 85 / 15 to 35.

[0976] In the case of a copolymer of TFE / a fluorine monomer represented by the general formula (160), (130) or (140) having 4 to 12 carbon atoms / a monomer providing a cross-linking site, the ratio is preferably 50 to 89.9 / 10 to 49.9 / 0.01 to 4 (mol %), more preferably 60 to 87.9 / 12 to 39.9 / 0.1 to 3.5, and still more preferably 65 to 84.8 / 15 to 34.8 / 0.2 to 3.

[0977] Outside these composition ranges, the properties as a rubber elastic body are lost and properties close to those of a resin tend to be exhibited.

[0978] As the above-mentioned perfluororubber, it is preferably at least one selected from the group consisting of TFE / fluorine monomer represented by general formula (140) / fluorine monomer copolymer providing cross-linking sites, TFE / perfluorovinyl ether copolymer represented by general formula (140), TFE / fluorine monomer copolymer represented by general formula (160) and TFE / fluorine monomer represented by general formula (160) / monomer copolymer providing cross-linking sites.

[0979] Examples of the perfluororubber include those described in International Publication No. 97 / 24381, Japanese Patent Publication No. 61-57324, Japanese Patent Publication No. 4-81608, and Japanese Patent Publication No. 5-13961.

[0980] The glass transition temperature of the fluororubber is preferably -70°C or higher, more preferably -60°C or higher, and even more preferably -50°C or higher, from the perspective of excellent compression set at high temperatures. Furthermore, from the perspective of good cold resistance, the glass transition temperature is preferably 5°C or lower, more preferably 0°C or lower, and even more preferably -3°C or lower.

[0981] The above-mentioned glass transition temperature can be calculated as follows: using a differential scanning calorimeter (manufactured by Mettler Toredo, DSC822e), 10 mg of the sample is heated at 10°C / min to obtain a DSC curve, and the temperature of the midpoint of the two intersections where the extension line of the baseline before and after the secondary phase transition of the DSC curve intersects with the tangent line at the inflection point of the DSC curve is calculated, and this is taken as the above-mentioned glass transition temperature.

[0982] In the above-mentioned fluororubbers, the Mooney viscosity ML (1+20) at 170°C is preferably 30 or greater, more preferably 40 or greater, and even more preferably 50 or greater, from the perspective of good heat resistance. Furthermore, from the perspective of good processability, the Mooney viscosity is preferably 150 or less, more preferably 120 or less, and even more preferably 110 or less.

[0983] In the above-mentioned fluororubbers, the Mooney viscosity ML (1+20) at 140°C is preferably 30 or greater, more preferably 40 or greater, and even more preferably 50 or greater, from the perspective of good heat resistance. Furthermore, from the perspective of good processability, the Mooney viscosity is preferably 180 or less, more preferably 150 or less, and even more preferably 110 or less.

[0984] In the above-mentioned fluororubbers, from the perspective of good heat resistance, the Mooney viscosity ML (1+10) at 100°C is preferably 10 or greater, more preferably 20 or greater, and even more preferably 30 or greater. Furthermore, from the perspective of good processability, the Mooney viscosity is preferably 120 or less, more preferably 100 or less, and even more preferably 80 or less.

[0985] The Mooney viscosity can be measured at 170° C. or 140° C. or 100° C. in accordance with JIS K6300 using a Mooney viscometer MV2000E manufactured by ALPHATECHNOLOGIES.

[0986] The aqueous dispersion of fluororubber obtained by the production method of the present invention can also be used in the form of gum or crumbs obtained by coagulation, drying, etc. using conventionally known methods. The surfactant used in the production method of the present invention can improve the stability of the aqueous dispersion and is more preferably used in polymerization methods in which initiators such as organic peroxides and chain transfer agents such as iodine or bromine compounds are added during the polymerization process.

[0987] The gum is a small granular mass made of fluororubber, and the crumb is formed when the fluororubber cannot maintain the small granular shape of the gum at room temperature and fuses with each other to form an amorphous mass.

[0988] The above-mentioned fluororubber can be processed into a fluororubber composition by adding a curing agent, a filler, etc.

[0989] Examples of the curing agent include polyols, polyamines, organic peroxides, organic tin, bis(aminophenol)tetramine, and bis(thioaminophenol).

[0990] The fluororubber composition is composed of the fluororubber described above and therefore contains substantially no emulsifier, and is excellent in that it is easily cross-linked during molding.

[0991] By using the above-mentioned fluororubber for molding, a fluororubber molded body can be obtained. The molding method is not particularly limited, and a known method using the above-mentioned curing agent can be used.

[0992] The fluororubber molded article is suitable for seals, gaskets, wire coverings, hoses, tubes, laminates, decorative articles, and the like, and is particularly suitable for parts for semiconductor manufacturing equipment, automobile parts, and the like.

[0993] As the hydrocarbon surfactant used in the production of the fluoropolymer, for example, hydrocarbon surfactants described in JP-A-2013-542308, JP-A-2013-542309, and JP-A-2013-542310 can be used.

[0994] The hydrocarbon surfactant may be a surfactant having a hydrophilic portion and a hydrophobic portion on the same molecule. These surfactants may be cationic, nonionic, or anionic.

[0995] Cationic hydrocarbon surfactants generally have a positively charged hydrophilic portion such as an alkylated ammonium halide such as an alkylated ammonium bromide and a hydrophobic portion such as a long-chain fatty acid.

[0996] Anionic hydrocarbon surfactants generally have a hydrophilic portion such as a carboxylate, sulfonate, or sulfate and a hydrophobic portion such as an alkyl group as a long-chain hydrocarbon portion.

[0997] Nonionic hydrocarbon surfactants generally do not contain charged groups but have a hydrophobic portion that is a long-chain hydrocarbon. The hydrophilic portion of a nonionic hydrocarbon surfactant contains a water-soluble functional group such as a vinyl ether chain derived from polymerization with ethylene oxide.

[0998] Examples of nonionic hydrocarbon surfactants

[0999] Polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerides, and derivatives thereof.

[1000] Specific examples of polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene behenyl ether.

[1001] Specific examples of polyoxyethylene alkylphenyl ether include polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether.

[1002] Specific examples of polyoxyethylene alkyl esters include polyethylene glycol monolaurate, polyethylene glycol monooleate, polyethylene glycol monostearate, and the like.

[1003] Specific examples of sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate.

[1004] Specific examples of polyoxyethylene sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monostearate.

[1005] Specific examples of glycerides include glyceryl monomyristate, glyceryl monostearate, glyceryl monooleate, and the like.

[1006] Specific examples of the above derivatives include polyoxyethylene alkylamines, polyoxyethylene alkylphenyl-formaldehyde condensates, and polyoxyethylene alkyl ether phosphates.

[1007] The above-mentioned ethers and esters may have an HLB value of 10-18.

[1008] Examples of the nonionic hydrocarbon surfactant include Triton (registered trademark) X series (X15, X45, X100, etc.), Tergitol (registered trademark) 15-S series, Tergitol (registered trademark) TMN series (TMN-6, TMN-10, TMN-100, etc.), and Tergitol (registered trademark) L series manufactured by The Dow Chemical Company; Pluronic (registered trademark) R series (31R1, 17R2, 10R5, 25R4 (m to 22, n to 23) manufactured by BASF; and Iconol (registered trademark) TDA series (TDA-6, TDA-9, TDA-10).

[1009] Examples of the anionic hydrocarbon surfactant include Versatic (registered trademark) 10 manufactured by Resolution Performance Products and Avanel S series (S-70, S-74, etc.) manufactured by BASF.

[1010] Examples of the anionic hydrocarbon surfactant include RLM (wherein R is a linear or branched alkyl group with or without a substituent having 1 or more carbon atoms, or a cyclic alkyl group with or without a substituent having 3 or more carbon atoms. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocyclic ring or form a ring. L is -ArSO3 - 、-SO3 - 、-SO4-、-PO3 - or -COO - , M is H, metal atom, NR 5 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 5 H or an organic group, -ArSO3 - An anionic surfactant represented by aryl sulfonate. 5 It 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.

[1011] Specifically, CH3-(CH2) represented by lauric acid, lauryl sulfate (dodecyl sulfate) and the like can be cited. n -LM (wherein n is an integer of 6 to 17. L and M are the same as above).

[1012] A mixture of substances in which R is an alkyl group having 12 to 16 carbon atoms and LM is a sulfate can also be used.

[1013] Examples of the anionic hydrocarbon surfactant include R6 (-LM)2(where R 6 It is a linear or branched alkylene group with or without a substituent having 1 or more carbon atoms, or a cyclic alkylene group with or without a substituent having 3 or more carbon atoms. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocycle or form a ring. L is -ArSO3 - 、-SO3 - 、-SO4-、-PO3 - or -COO - , M is H, metal atom, NR 5 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 5 H or an organic group, -ArSO3 - Anionic surfactant represented by aryl sulfonate.

[1014] Examples of the anionic hydrocarbon surfactants include R 7 (-LM)3(where R 7 It is a linear or branched alkylene group with or without a substituent having 1 or more carbon atoms, or a cyclic alkylene group with or without a substituent having 3 or more carbon atoms. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocycle or form a ring. L is -ArSO3 - 、-SO3 - 、-SO4-、-PO3 - or -COO - , M is H, metal atom, NR 5 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 5 Is H or an organic group. -ArSO3 - Anionic surfactant represented by aryl sulfonate.

[1015] As R 5 , preferably H or an alkyl group, more preferably H or an alkyl group having 1 to 10 carbon atoms, further preferably H or an alkyl group having 1 to 4 carbon atoms.

[1016] In this specification, unless otherwise specified, "substituent" refers to a group that can be substituted. Examples of such "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl group, an aliphatic sulfonyloxy group, an aromatic sulfonyloxy group, a heterocyclic sulfonyloxy group, a sulfamoyl group, an aliphatic sulfonamide group, an aromatic sulfonamide group, a heterocyclic sulfonamide group, an amino group, an aliphatic amino group, an aromatic amino group, a heterocyclic amino group, an aliphatic oxycarbonylamino group, an aromatic oxycarbonylamino group, a heterocyclic oxycarbonylamino group, an aliphatic sulfinyl group, an aromatic sulfinyl group, an aliphatic thiol group, an aromatic thiol group, a hydroxyl group, a cyano group, a sulfo group, a carboxyl group, an aliphatic oxyamino group, an aromatic oxyamino group, a carbamoylamino group, a sulfamoylamino group, a halogen atom, a sulfamoylcarbamoyl group, a carbamoylsulfamoyl group, a dialiphatic oxyphosphinyl group, or a diaromatic oxyphosphinyl group.

[1017] Other examples of hydrocarbon surfactants include siloxane hydrocarbon surfactants. 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 hydrocarbon surfactants includes a distinct hydrophobic portion and a hydrophilic portion. The hydrophobic portion comprises one or more dihydrocarbylsiloxane units, where all substituents on the siloxane atoms are hydrocarbons.

[1018] In the case where the carbon atoms of the dihydrocarbyl group may be substituted by halogens such as fluorine, these siloxane hydrocarbon-based surfactants can also be regarded as hydrocarbon-based surfactants in the sense that the monovalent substituents on the carbon atoms of the dihydrocarbyl group are hydrogen atoms.

[1019] The hydrophilic portion of the silicone surfactant may include one or more polar moieties containing ionic groups, such as sulfates, sulfonates, phosphonates, phosphates, carboxylates, carbonates, sulfosuccinates, taurine (salts / esters) (in the form of free acids, salts, or esters), phosphine oxides, betaines, betaine copolyols, and quaternary ammonium salts. The ionic hydrophobic portion may also include ionic functionalized silicone grafts.

[1020] Examples of such silicone hydrocarbon surfactants include polydimethylsiloxane-grafted (meth)acrylates, polydimethylsiloxane-grafted polyacrylates, and polydimethylsiloxane-grafted quaternary amines.

[1021] The polar portion of the hydrophilic portion of silicone surfactants can include polyethers such as polyethylene oxide (PEO) and mixed polyethylene oxide / propylene oxide polyethers (PEO / PPO); monosaccharides and disaccharides; and nonionic groups formed from water-soluble heterocycles such as pyrrolidone. The ratio of ethylene oxide to propylene oxide (EO / PO) can vary in mixed polyethylene oxide / propylene oxide polyethers.

[1022] The hydrophilic portion of the silicone surfactant may also comprise a combination of an ionic portion and a nonionic portion. Examples of such portions include ionic end-functionalized or randomly functionalized polyethers or polyols. Preferred for the practice of the present invention are silicones having a nonionic portion, i.e., nonionic silicone surfactants.

[1023] The hydrophobic and hydrophilic portions of the structure of siloxane surfactants can be arranged in the form of diblock polymers (AB), triblock polymers (ABA) (where "B" represents the siloxane portion of the molecule), or multiblock polymers. Alternatively, the siloxane surfactants may include grafted polymers.

[1024] Silicone hydrocarbon surfactants are also disclosed in US Pat. No. 6,841,616.

[1025] Examples of the siloxane-based anionic hydrocarbon surfactant include SilSense available from Noveon (registered trademark) Consumer Specialties of Lubrizol Advanced Materials, Inc. TM PE-100 Siloxane, SilSense TM CA-1 siloxane, etc.

[1026] Examples of the anionic hydrocarbon surfactant include Lankropol (registered trademark) K8300, a sulfosuccinate surfactant manufactured by Akzo Nobel Surface Chemistry LLC.

[1027] Examples of the sulfosuccinate surfactant include diisodecyl sulfosuccinate sodium salt (Emulsogen (registered trademark) SB10 from Clariant) and diisotridecyl sulfosuccinate sodium salt (Polirol (registered trademark) TR / LNA from Cesapinia Chemicals).

[1028] Examples of the hydrocarbon surfactant include PolyFox (registered trademark) surfactants manufactured by Omnova Solutions, Inc.TM PF-156A, PolyFoX TM PF-136A, etc.).

[1029] The hydrocarbon surfactant is preferably an anionic hydrocarbon surfactant. As the anionic hydrocarbon surfactant, the above-mentioned anionic hydrocarbon surfactants can be used, and for example, the following hydrocarbon surfactants can be preferably used.

[1030] Examples of the anionic hydrocarbon surfactant include the following formula (α):

[1031] R 10 -COOM(α)

[1032] (Where R 10 It is a monovalent organic group containing one or more carbon atoms. M is H, metal atom, NR 11 4. an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted; R 11 is H or an organic group, which may be the same or different. ) is a compound (α) represented by 11 , preferably H or C 1-10 An organic group, more preferably H or C 1-4 of organic groups.

[1033] From the perspective of surface activity, R 10 The number of carbon atoms in is preferably 2 or more, more preferably 3 or more. In addition, from the perspective of water solubility, R 10 The number of carbon atoms is preferably 29 or less, more preferably 23 or less.

[1034] Examples of the metal atom of M include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li are preferred. M is preferably H, a metal atom, or NR 11 4, more preferably H, alkali metal (Group 1), alkaline earth metal (Group 2) or NR 11 4, further preferably H, Na, K, Li or NH4, further more preferably Na, K or NH4, particularly preferably Na or NH4, most preferably NH4.

[1035] Examples of the compound (α) include R 12 -COOM (where R 12It is a linear or branched alkyl, alkenyl, alkylene or alkenylene group with or without a substituent having 1 or more carbon atoms, or a cyclic alkyl, alkenyl, alkylene or alkenylene group with or without a substituent having 3 or more carbon atoms, which may contain an ether bond. When the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocycle or form a ring. M is the same as above. An anionic surfactant represented by ).

[1036] Specifically, CH3-(CH2) n -COOM (wherein n is an integer of 2 to 28 and M is the same as above).

[1037] From the viewpoint of emulsion stability, the anionic hydrocarbon-based surfactant may not contain a carbonyl group (excluding the carbonyl group in the carboxyl group).

[1038] As the anionic hydrocarbon surfactant not containing a carbonyl group, for example, the following formula (A) can be preferably exemplified: R-COO-M (A) (wherein, R is an alkyl group, an alkenyl group, an alkylene group or an alkenylene group, and these groups may contain an ether bond. M is H, a metal atom, NR 11 4. Imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent. 11 The compound is the same or different H or an organic group having 1 to 10 carbon atoms.

[1039] In the above formula (A), R is preferably an alkyl group or an alkenyl group (these groups may include an ether group). The alkyl group or alkenyl group in R may be linear or branched. The number of carbon atoms in R is not limited, and is, for example, 2 to 29, preferably 4 to 29.

[1040] The alkyl, alkenyl, alkylene or alkenylene group in R preferably does not contain a carbonyl group (excluding the carbonyl group in an ester group).

[1041] When the alkyl group is linear, the number of carbon atoms in R is preferably 3 to 29, more preferably 5 to 23. When the alkyl group is branched, the number of carbon atoms in R is preferably 5 to 35, more preferably 11 to 23.

[1042] When the alkenyl group is linear, R preferably has 2 to 29 carbon atoms, more preferably 9 to 23. When the alkenyl group is branched, R preferably has 2 to 29 carbon atoms, more preferably 3 to 29, and even more preferably 9 to 23 carbon atoms.

[1043] Examples of the alkyl group and alkenyl group include a methyl group, an ethyl group, an isobutyl group, a tert-butyl group, and a vinyl group.

[1044] Examples of the anionic hydrocarbon surfactant include butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, (9,12,15)-linolenic acid, (6,9,12)-linolenic acid, eleostearic acid, arachidic acid, 8,11-eicosadienoic acid, melamine, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, crotonic acid, Myristoleic acid, palmitoleic acid, hexadecenoic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, α-eleostearic acid, β-eleostearic acid, melamine, dihomo-γ-linolenic acid, eicosatrienoic acid, stearatetraenoic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, borsovaleric acid, eicosapentaenoic acid, all-cis-4,7,10,13,16-docosapentaenoic acid, clopanodonic acid, tetracospentaenoic acid, docosahexaenoic acid, all-cis-6,9,12,15,18,21-tetracosahexanoic acid, and salts thereof.

[1045] Particularly preferred is at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecanoic acid, palmitic acid, and salts thereof, more preferred is lauric acid and a salt thereof, particularly preferred is a salt of lauric acid, and most preferred is sodium laurate or ammonium laurate.

[1046] Examples of the salt include a salt in which the hydrogen of the carboxyl group is a metal atom of the above formula M, NR 11 4. The substance may be substituted imidazolium, may be substituted pyridinium, or may be substituted phosphonium, but is not particularly limited.

[1047] Preferred examples of the hydrocarbon surfactant include the following general formula (1-0):

[1048] [Chemistry 18]

[1049]

[1050] (Where R 1 ~R 5 represents H or a monovalent substituent, wherein R 1 and R 3 At least one of them represents the general formula: -YR 6 The group shown, R 2 and R 5 At least one of the following represents a group represented by the general formula: -XA or a group represented by the general formula: -YR 6 The groups shown.

[1051] In addition, X may be the same or different at each occurrence and represents a divalent linking group or a bond;

[1052] A may be the same or different at each occurrence, and represents -COOM, -SO3M or -OSO3M (M is H, metal atom, NR 7 4. an imidazolium with or without a substituent, a pyridinium with or without a substituent, or a phosphonium with or without a substituent, R 7 is H or an organic group);

[1053] Y may be the same or different at each occurrence and represents a group selected from -S(=O)2-, -O-, -COO-, -OCO-, -CONR 8 -and-NR 8 The divalent linking group or bond in the group consisting of CO-, R 8 represents H or an organic group;

[1054] R 6 Each occurrence may be the same or different, and represents an alkyl group having 1 or more carbon atoms that 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 atoms.

[1055] R 1 ~R 5 Any two of them may be bonded to each other to form a ring. ) represented by surfactant (hereinafter also referred to as surfactant (1-0)).

[1056] The surfactant (1-0) will be described.

[1057] Where R 1 ~R 5 represents H or a monovalent substituent, wherein R 1 and R 3 At least one of them represents the general formula: -YR 6 The group shown, R 2 and R 5 At least one of the following represents a group represented by the general formula: -XA or a group represented by the general formula: -YR 6 The group shown. 1 ~R 5 Any two of them may be combined with each other to form a ring.

[1058] As R 1 The substituent that the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxyl group, and particularly preferably a methyl group or an ethyl group.

[1059] As R 1The above-mentioned alkyl group preferably does not contain a carbonyl group.

[1060] In the above alkyl group, less than 75% of hydrogen atoms bonded to carbon atoms may be substituted by halogen atoms, less than 50% may be substituted by halogen atoms, or less than 25% may be substituted by halogen atoms. Preferably, the alkyl group is a non-halogenated alkyl group containing no halogen atoms such as fluorine atoms and chlorine atoms.

[1061] The above-mentioned alkyl group preferably has no substituent.

[1062] As R 1 , preferably a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms with or without a substituent, or a cyclic alkyl group having 3 to 10 carbon atoms with or without a substituent, more preferably a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms without a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms without a carbonyl group, further preferably a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms without a substituent, further more preferably a straight-chain or branched-chain alkyl group having 1 to 3 carbon atoms without a substituent, particularly preferably a methyl group (-CH3) or an ethyl group (-C2H5), most preferably a methyl group (-CH3).

[1063] As a monovalent substitu...

Claims

1. A method for producing a refined fluoropolymer aqueous dispersion, It is characterized in that The method comprises a step A of contacting an aqueous fluoropolymer dispersion obtained by using a hydrocarbon-based surfactant with an anion exchange resin A or a synthetic adsorbent. The anion exchange resin A has an ion exchange group represented by the following general formula (A1) or an ion exchange group represented by the following general formula (A2), General formula (A1): -N + R 1 R 2 R 3 X - In the formula, R 1 , R 2 and R 3 are identically or differently hydrogen atoms or organic groups, R 1 , R 2 and R 3 At least one of them is an organic group having 3 or more carbon atoms, X is a counter ion, General formula (A2): -NR 4 R 5 In the formula, R 4 and R 5 are identically or differently hydrogen atoms or organic groups, R 4 and R 5 At least one of them is an organic group having 2 or more carbon atoms.

2. The manufacturing method according to claim 1, in, In the general formula (A1), R 1 , R 2 and R 3 At least one of them is an organic group having 4 or more carbon atoms.

3. The manufacturing method according to claim 1 or 2, in, In the general formula (A1), R 1 , R 2 and R 3 It is an organic group having 2 or more carbon atoms.

4. The production method according to any one of claims 1 to 3, in, The pore volume of the synthetic adsorbent is 0.6 cm 3 / g~2.5cm 3 / g.

5. The production method according to any one of claims 1 to 4, in, The step A is carried out two or more times.

6. The production method according to any one of claims 1 to 5, in, The method further comprises a step B of contacting the aqueous fluoropolymer dispersion with an anion exchange resin B, The anion exchange resin B is different from the anion exchange resin A.

7. The manufacturing method according to claim 6, in, The anion exchange resin B has an ion exchange group represented by the following general formula (B1) or an ion exchange group represented by the following general formula (B2), General formula (B1): -N + (CH 3 ) 3 X - In the formula, X represents a counter ion, General formula (B2): -N + (CH 3 ) 2 (C 2 H 4 OH)X - In the formula, X represents a counter ion.

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

9. The production method according to any one of claims 1 to 8, in, The method further comprises the step C of adding a nonionic surfactant to the aqueous fluoropolymer dispersion after the step A to perform phase separation and concentration.

10. The manufacturing method according to claim 9, in, The step C is performed two or more times.

11. The manufacturing method according to claim 10, in, In the first step C, the phase separation concentration is performed by heating the aqueous fluoropolymer dispersion at a temperature 5°C or higher lower than the cloud point of the nonionic surfactant and then leaving it to stand to separate into a supernatant phase and a concentrated phase.

12. The manufacturing method according to claim 10 or 11, in, In the second step C, the phase separation concentration is performed by heating the aqueous fluoropolymer dispersion at a temperature 5°C or higher lower than the cloud point of the nonionic surfactant and then allowing it to stand to separate into a supernatant phase and a concentrated phase.

13. An aqueous fluoropolymer dispersion comprising a fluoropolymer and water, It is characterized in that It contains a compound represented by the following general formula (1), wherein the total content of the compounds represented by the following general formula (1) is 1000 ppb or less relative to the fluoropolymer, General formula (1): (H-(CF 2 ) m -COO) p M 1 Wherein, m is 3 to 19, M 1 H, metal atoms, NR 5 4 , an imidazolium which may be substituted, a pyridinium which may be substituted, or a phosphonium which may be substituted, p is 1 or 2, R 5 They may be the same or different and are H or an organic group having 1 to 10 carbon atoms.

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