RU2819636C1 - Method of producing aqueous dispersion of fluorine-containing elastomer and composition - Google Patents

Abstract

FIELD: chemical or physical processes.

SUBSTANCE: present invention relates to a method of producing an aqueous dispersion of a fluorine-containing elastomer, as well as a composition for producing a molded article. Method involves polymerisation in an aqueous medium of a fluorine-containing monomer in the presence of polymer (1) containing polymerisation unit (1) based on monomer (1) of general formula CF₂=CF-R-CZ¹Z²-COOM, where R is a binding group, each of Z¹ and Z² is independently F or CF₃, and M is H, a metal atom, NR⁷ ₄, imidazolium, optionally containing a substitute, pyridinium, optionally containing a substitute, or phosphonium, optionally containing a substitute, where R⁷ is H or an organic group.

EFFECT: method enables to produce a sufficient amount of fluorine-containing elastomer particles at a sufficient polymerisation rate, while inhibiting adhesion of the fluorine-containing elastomer in the polymerisation tank.

19 cl, 2 tbl, 3 ex

Description

Field of technology to which the invention relates

[0001] The present invention relates to a method for preparing an aqueous dispersion of a fluorine-containing elastomer and to a composition.

State of the art

[0002] Patent Document 1 describes the possibility of using an oligomeric fluorosulfinic compound and/or an ethylenically unsaturated polymerizable monomeric fluorosulfinic compound for polymerizing in an aqueous emulsion at least one ethylenically unsaturated fluorosulfinic compound, such as a fluorinated olefin, to produce a fluoropolymer having partially or fully fluorinated frame.

Links

Patent document

[0003] Patent Document 1: Japanese translation of PCT International Application Publication No. 2013-545877

Essence invention

The problem solved by the invention

[0004] An object of the present invention is to provide a method for producing an aqueous dispersion of fluorine-containing elastomer, the method is capable of producing a sufficient amount of fluorine-containing elastomer particles at a sufficient polymerization rate, suppressing the adhesion of the fluorine-containing elastomer in the polymerization tank.

Remedies

[0005] The present invention provides a method for producing an aqueous dispersion of a fluorine-containing elastomer, comprising polymerizing a fluorine-containing monomer in the presence of a polymer (1) containing a polymerization unit (1) based on the monomer (1) represented by the general formula (1) and an aqueous medium to obtain an aqueous fluorine-containing elastomer dispersions:

CF ₂ =CF-R-CZ ¹ Z ² -COOM (1)

where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R7 represents H or an organic group.

[0006] In the production method of the present invention, the monomer (1) is preferably a monomer (2) represented by the general formula (2):

CF ₂ =CF(-O-Rf-COOM) (2)

where Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is as described above.

In the production method of the present invention, the polymer (1) preferably has a weight average molecular weight of 1.4× ¹⁰⁴ or more.

In the production method of the present invention, the content of the polymerization unit (1) is preferably 50 mol% or more with respect to all polymerization units constituting the polymer (1).

In the production method of the present invention, the amount of added polymer (1) is preferably from 0.0001 to 20% by weight, based on 100% by weight of the aqueous medium.

In the production method of the present invention, it is preferable that the polymerization of the fluorine-containing monomer is carried out in the presence of a polymerization initiator, and that the amount of added polymerization initiator is preferably from 0.00001 to 10% by weight, based on 100% by weight of the fluorine-containing monomer.

In the production method of the present invention, it is preferable that the polymerization of the fluorine-containing monomer is carried out substantially in the absence of a fluorine-containing surfactant.

In the production method of the present invention, the fluorine-containing monomer is preferably vinylidene fluoride or tetrafluoroethylene.

In the production method of the present invention, the fluorine-containing monomer is preferably vinylidene fluoride.

In the production method of the present invention, the fluorine-containing elastomer preferably contains -CH ₂ - in the main chain.

[0007] In addition, the present invention provides a composition containing a fluorine-containing elastomer and a polymer (1) containing a polymerization unit (1) based on a monomer (1) represented by the general formula (1):

CF ₂ =CF-R-CZ ¹ Z ² -COOM (1)

where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0008] In the composition of the present invention, the monomer (1) is preferably a monomer (2) represented by the general formula (2):

CF ₂ =CF(-O-Rf-COOM) (2)

where Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is as described above.

[0009] In the composition of the present invention, the polymer (1) preferably has a weight average molecular weight of 1.4 × 10 ⁴ or more.

In the composition of the present invention, the content of the polymerization unit (1) is preferably 50 mol% or more with respect to all polymerization units constituting the polymer (1).

In the composition of the present invention, the content of the polymer (1) is preferably from 0.00001 to 20% by weight with respect to the fluorine-containing monomer.

The composition of the present invention is preferably an aqueous dispersion.

In the composition of the present invention, the concentration of solids in the aqueous dispersion is preferably from 5 to 50% by weight with respect to the aqueous dispersion.

Preferably, the composition of the present invention is substantially free of fluorosurfactant.

In the composition of the present invention, the fluorine-containing elastomer preferably contains a vinylidene fluoride unit or a tetrafluoroethylene unit.

In the composition of the present invention, the fluorine-containing elastomer preferably contains a vinylidene fluoride unit.

In the composition of the present invention, the fluorine-containing elastomer preferably contains -CH ₂ - in the main chain.

Impact of the invention

[0010] The present invention can provide a method for producing an aqueous dispersion of a fluorine-containing elastomer, wherein the method is capable of producing a sufficient amount of fluorine-elastomer particles at a sufficient polymerization rate to suppress the adhesion of the fluorine-containing elastomer in the polymerization tank.

Description of Embodiments

[0011] As used herein, the fluorine-containing elastomer is an amorphous fluoropolymer. The term "amorphous" means that the magnitude of the melting peak (ΔH) that appears in differential scanning calorimetry (DSC) (temperature rise rate 10°C/min) or differential thermal analysis (DTA) (temperature rise rate 10°C/min) fluoropolymer is 4.5 J/g or less. The fluorine-containing elastomer exhibits elastomeric characteristics when cross-linked. Elastomeric characteristics mean those characteristics in which a polymer can stretch and retain its original length when the force required to stretch the polymer is no longer applied.

[0012] As used herein, a perfluoromonomer is a monomer that does not contain a carbon atom-hydrogen atom bond in the molecule. The perfluoromonomer may be a monomer containing carbon atoms and fluorine atoms in which some of the fluorine atoms bonded to the carbon atoms are replaced by chlorine atoms, or may be a monomer containing a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a boron atom or silicon atom in addition to carbon atoms. The perfluoromonomer is preferably a monomer in which all hydrogen atoms are replaced by fluorine atoms. The perfluoromonomer does not include a monomer that provides a cross-linkable group.

[0013] A monomer that provides a cross-linking active site is a monomer (a curing active site monomer) that provides a cross-linking active site fluoropolymer to form a cross-link with a cross-linking agent. The monomer that provides the cross-linking active site includes the monomer that provides the cross-linkable group.

[0014] Herein, the content of the corresponding monomer units constituting the fluorine-containing elastomer can be calculated using an appropriate combination of NMR, FT-IR, elemental analysis and X-ray fluorescence analysis according to the types of monomers.

[0015] As used herein, the term “organic group” means a group containing one or more carbon atoms, or a group formed by the removal of one hydrogen atom from an organic compound.

Examples of an "organic group" include:

an alkyl group, optionally containing one or more substituents,

an alkenyl group, optionally containing one or more substituents,

an alkynyl group, optionally containing one or more substituents,

a cycloalkyl group, optionally containing one or more substituents,

a cycloalkenyl group, optionally containing one or more substituents,

a cycloalkadienyl group, optionally containing one or more substituents,

an aryl group, optionally containing one or more substituents,

an aralkyl group, optionally containing one or more substituents,

a non-aromatic heterocyclic group, optionally containing one or more substituents,

a heteroaryl group, optionally containing one or more substituents,

cyano group,

formyl group,

RaO-,

RaCO-,

RaSO ₂ -,

RaCOO-,

RaNRaCO-,

RaCONRa-,

RaOCO-,

RaOSO ₂ -, and

_RaNRbSO2 -

where each Ra independently represents

an alkyl group, optionally containing one or more substituents,

an alkenyl group, optionally containing one or more substituents,

an alkynyl group, optionally containing one or more substituents,

a cycloalkyl group, optionally containing one or more substituents,

a cycloalkenyl group, optionally containing one or more substituents,

a cycloalkadienyl group, optionally containing one or more substituents,

an aryl group, optionally containing one or more substituents,

an aralkyl group, optionally containing one or more substituents,

a non-aromatic heterocyclic group, optionally containing one or more substituents, or

a heteroaryl group optionally containing one or more substituents, and

Rb independently represents H or an alkyl group, optionally containing one or more substituents.

The organic group is preferably an alkyl group, optionally containing one or more substituents.

The term "substituent" as used herein means a group capable of replacing another atom or group. Examples of the "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic hydroxy group, an aromatic hydroxy group, a heterocyclic hydroxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, The aliphatic sulphonal group, an aromatic sulphonal group, a heterocyclic sulphonal group, an aliphatic sulphonyloxy group, aromatic sulphonyloxy group, heterocyclic sulfonyxic group, sulfamoil group, an aliphatic sulfonamy group, aromatic sulfonamy group, and a heterocyclical group a worldly group, amino group, an aliphatic amino group, aromatic amino group, heterocyclic amino group, aliphatic oxycarbonylamino group, aromatic oxycarbonylamino group, heterocyclic oxycarbonylamino group, aliphatic sulfinyl group, aromatic sulfinyl group, aliphatic thio group, aromatic thio group, hydroxy group, cyano group, sulfo group, carboxy group, aliphatic oxyamino group, 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.

[0017] The aliphatic group may be saturated or unsaturated and may include a hydroxyl group, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group and the like. Examples of the aliphatic group include alkyl groups having generally 1 to 8, and preferably 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a vinyl group, a cyclohexyl group and a carbamoylmethyl group.

[0018] An aromatic group may contain, for example, a nitro group, a halogen atom, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group and the like. Examples of the aromatic group include aryl groups having generally 6 to 12, and preferably 6 to 10 carbon atoms, such as a phenyl group, a 4-nitrophenyl group, a 4-acetylaminophenyl group and a 4-methanesulfonylphenyl group.

[0019] The heterocyclic group may contain a halogen atom, a hydroxyl group, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group, or the like. Examples of the heterocyclic group include 5- or 6-membered heterocyclic groups containing generally 2 to 12, and preferably 2 to 10 carbon atoms, such as the 2-tetrahydrofuryl group and the 2-pyrimidyl group.

[0020] 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 hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group group, carbamoylamino group and the like. Examples of the acyl group include acyl groups having generally 2 to 8, and preferably 2 to 4 carbon atoms, such as an acetyl group, a propanoyl group, a benzoyl group and a 3-pyridinecarbonyl group.

[0021] An acylamino group may include an aliphatic group, an aromatic group, a heterocyclic group and the like, and may contain, for example, an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propanoylamino group or the like. Examples of the acylamino group include acylamino groups containing from 2 to 12, and preferably from 2 to 8 carbon atoms in total, and alkylcarbonylamino groups containing from 2 to 8 carbon atoms in total, such as an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group and propanoylamino group.

[0022] The aliphatic oxycarbonyl group may be saturated or unsaturated and may include a hydroxyl group, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group and the like. Examples of the aliphatic oxycarbonyl group include alkoxycarbonyl groups having generally 2 to 8, and preferably 2 to 4 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group and a (tert)-butoxycarbonyl group.

[0023] The carbamoyl group may include an aliphatic group, an aromatic group, a heterocyclic group and the like. Examples of the carbamoyl group include unsubstituted carbamoyl group and alkylcarbamoyl groups having generally 2 to 9 carbon atoms, and preferably unsubstituted carbamoyl group and alkylcarbamoyl groups having generally 2 to 5 carbon atoms, such as N-methylcarbamoyl group, N, N -dimethylcarbamoyl group and N-phenylcarbamoyl group.

[0024] The aliphatic sulfonyl group may be saturated or unsaturated and may include a hydroxyl group, an aromatic group, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group and the like . Examples of the aliphatic sulfonyl group include alkylsulfonyl groups having generally 1 to 6, and preferably 1 to 4 carbon atoms, such as a methanesulfonyl group.

[0025] The aromatic sulfonyl group may contain a hydroxyl group, an aliphatic group, an aliphatic hydroxy group, a carbamoyl group, an aliphatic oxycarbonyl group, an aliphatic thio group, an amino group, an aliphatic amino group, an acylamino group, a carbamoylamino group and the like. Examples of the aromatic sulfonyl group include an arylsulfonyl group having a total of 6 to 10 carbon atoms, such as a benzenesulfonyl group.

[0026] An amino group may include an aliphatic group, an aromatic group, a heterocyclic group or the like.

[0027] An acylamino group may include, for example, an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propanoylamino group, or the like. Examples of the acylamino group include acylamino groups having a total of 2 to 12, and preferably 2 to 8 carbon atoms, and more preferably alkylcarbonylamino groups having a total of 2 to 8 carbon atoms, such as an acetylamino group, a benzoylamino group, 2-pyridinecarbonylamino group and propanoylamino group.

[0028] The aliphatic sulfonamide group, aromatic sulfonamide group and heterocyclic sulfonamide group may be, for example, a methanesulfonamide group, a benzenesulfonamide group and a 2-pyridine sulfonamide group, respectively.

[0029] The sulfamoyl group may include an aliphatic group, an aromatic group, a heterocyclic group or the like. Examples of the sulfamoyl group include sulfamoyl group, alkylsulfamoyl groups having generally 1 to 9 carbon atoms, dialkylsulfamoyl groups having generally 2 to 10 carbon atoms, arylsulfamoyl groups having generally 7 to 13 carbon atoms, and heterocyclic sulfamoyl groups containing 2 to 10 carbon atoms, a total of 12 carbon atoms, and more preferably a sulfamoyl group, alkylsulfamoyl groups containing a total of 1 to 7 carbon atoms, dialkylsulfamoyl groups containing a total of 3 to 6 carbon atoms, arylsulfamoyl groups, containing in total from 6 to 11 carbon atoms, and heterocyclic sulfamoyl groups containing in total from 2 to 10 carbon atoms, such as a sulfamoyl group, a methylsulfamoyl group, an N,N-dimethylsulfamoyl group, a phenylsulfamoyl group and a 4-pyridine sulfamoyl group.

[0030] The aliphatic oxy group may be saturated or unsaturated and may contain a methoxy group, ethoxy group, isopropyloxy group, cyclohexyloxy group, methoxyethoxy group or the like. Examples of the aliphatic hydroxy group include alkoxy groups having generally 1 to 8, and preferably 1 to 6 carbon atoms, such as a methoxy group, ethoxy group, isopropyloxy group, cyclohexyloxy group and methoxyethoxy group.

[0031] The aromatic amino group and the heterocyclic amino group may contain an aliphatic group, an aliphatic hydroxy group, a halogen atom, a carbamoyl group, a heterocyclic group containing a ring fused with an aryl group, or an aliphatic oxycarbonyl group, and preferably an aliphatic group containing from 1 to 4 carbon atoms, an aliphatic oxy group containing from 1 to 4 carbon atoms, a halogen atom, a carbamoyl group containing from 1 to 4 carbon atoms, a nitro group or an aliphatic oxycarbonyl group having a total of 2 to 4 carbon atoms.

[0032] The aliphatic thio group may be saturated or unsaturated, and examples thereof include alkylthio groups containing generally from 1 to 8, and more preferably from 1 to 6 carbon atoms, such as methylthio group, ethylthio group, carbamoylmethylthio group and tert-thio group. butylthio group.

[0033] The carbamoylamino group may include an aliphatic group, an aryl group, a heterocyclic group or the like. Examples of the carbamoylamino group include carbamoylamino group, 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 containing in total from 3 to 12 carbon atoms, and preferably a carbamoylamino group, alkylcarbamoylamino groups containing in total from 2 to 7 carbon atoms, dialkylcarbamoylamino groups containing in total from 3 to 6 carbon atoms, arylcarbamoylamino groups containing in total from 7 up to 11 carbon atoms, and heterocyclic carbamoylamino groups containing in total from 3 to 10 carbon atoms, such as carbamoylamino group, methylcarbamoylamino group, N,N-dimethylcarbamoylamino group, phenylcarbamoylamino group and 4-pyridinecarbamoylamino group.

[0034] A range denoted by endpoints as used herein includes all numeric values within the range (e.g., the range 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98 etc).

[0035] The phrase "at least one" as used herein includes all numerical values equal to or greater than 1 (e.g., at least 2, at least 4, at least 6, at least at least 8, at least 10, at least 25, at least 50, at least 100 and the like).

[0036] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0037] The present invention relates to a method for producing an aqueous dispersion of a fluorine-containing elastomer, including the polymerization of a fluorine-containing monomer in the presence of a polymer (1) containing a polymerization unit (1), based on the monomer (1) represented by the general formula (1), and an aqueous medium for obtaining an aqueous dispersion of fluorine-containing elastomer:

CF ₂ =CF-R-CZ ¹ Z ² -COOM (1)

where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0038] Since the production method of the present invention involves polymerizing a fluorine-containing monomer in the presence of a polymer (1) and an aqueous medium, it is possible to obtain a sufficient amount of fluorine-elastomer particles at a sufficient polymerization rate while suppressing the adhesion of the fluorine-containing elastomer to the polymerization tank.

[0039] In the production method of the present invention, one type of monomer or two or more types of monomers can be used as the monomer (1) represented by the general formula (1).

[0040] R represents a linking group. A "linking group" as used herein is a divalent linking group. The linking group may be a single bond, and preferably contains at least one carbon atom, and the number of carbon atoms may be 2 or more, 4 or more, 8 or more, 10 or more, or 20 or more. The upper limit is not limited and may be, for example, 100 or less and may be 50 or less.

[0041] The linking group may be linear or branched, cyclic or acyclic, saturated or unsaturated, substituted or unsubstituted, and may optionally contain one or more heteroatoms selected from the group consisting of sulfur, oxygen and nitrogen, and optionally , may contain one or more functional groups selected from the group consisting of ester, amide, sulfonamide, carbonyl, carbonate, urethane, urea and carbamate. The linking group may not contain carbon atoms and may be a catenary heteroatom such as oxygen, sulfur or nitrogen.

[0042] R is preferably a catenary heteroatom such as oxygen, sulfur or nitrogen, or a divalent organic group.

[0043] When R represents a divalent organic group, the hydrogen atom bonded to the carbon atom may be replaced by a halogen other than fluorine, such as chlorine, and the divalent organic group may or may not contain a double bond. Additionally, R may be linear or branched and may be cyclic or acyclic. R may also contain a functional group (eg, ester, ether, ketone (keto group), amine, halide and the like).

[0044] R may also be a fluorine-free divalent organic group or a partially fluorinated or perfluorinated divalent organic group.

[0045] R may be, for example, a hydrocarbon group in which no fluorine atom is bonded to a carbon atom, a hydrocarbon group in which some of the hydrogen atoms bonded to the carbon atoms are replaced by fluorine atoms, or a hydrocarbon group in which all the hydrogen atoms bonded to the carbon atoms are replaced by fluorine atoms, and they may contain an oxygen atom, may contain a double bond, and may contain a functional group.

[0046] R preferably represents a hydrocarbon group containing from 1 to 100 carbon atoms and optionally containing an ether linkage or a keto group, wherein some or all of the hydrogen atoms associated with the carbon atoms in the hydrocarbon group may be replaced by fluorine.

[0047] R is preferably selected from at least -(CH ₂ ) _a -, -(CF ₂ ) _a - _, -O-(CF ₂ ) _a -, -(CF ₂ ) _a -O-(CF ₂ ) _b -, -O(CF ₂ ) _a -O-(CF ₂ ) _b -, -(CF ₂ ) _a -[O-(CF ₂ ) _b ] _c -, -O(CF ₂ ) _a -[O -(CF ₂ ) _b ] _c -, -[(CF ₂ ) _a -O] _b -[(CF ₂ ) _c -O] _d -, -O[(CF ₂ ) _a -O] _b -, -O [(CF ₂ ) _a -O] _b -[(CF ₂ ) _c -O] _d -, -O-[CF ₂ CF(CF ₃ )O] _a -(CF ₂ ) _b -, -O-(CF ₂ ) _a -O-[CF(CF ₃ )CF ₂ O] _b -O-, -O-[CF ₂ CF(CF ₃ )O] _a -(CF ₂ ) _b -O-, -O-[CF ₂ CF(CF ₃ )O] _a -(CF ₂ ) _b -O-[CF(CF ₃ )CF ₂ O] _c -O-, -[CF ₂ CF(CF ₃ )O] _a -, -[CF (CF ₃ )CF ₂ O] _a -, -(CF ₂ ) _a -O-[CF(CF ₃ )CF ₂ O] _a - _, -(CF ₂ ) _a -O-[CF(CF ₃ )CF ₂ O] _a -(CF ₂ ) _b -, -[CF ₂ CF(CF ₃ )] _a -CO-(CF ₂ ) _b - and combinations of two or more of them.

In the formulas, a, b, c and d are each independently equal to at least 1 or more. a, b, c and d, each independently may be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limits of a, b, c and d are equal to, for example, 100.

R is preferably selected from at least -O-CF ₂ -, -O-CF ₂ CF ₂ -, -O-CF ₂ CF ₂ -O-, -O-CF ₂ CF ₂ CF ₂ -, -O- CF ₂ CF ₂ CF ₂ -O-, -O-CF ₂ CF(CF ₃ )-O-, -O-CF ₂ CF ₂ -O-CF(CF ₃ )CF ₂ -O-, -O-CF ₂ CF(CF ₃ )-O-CF ₂ CF ₂ -O-, and -O-CF ₂ CF(CF ₃ )-O-CF ₂ -.

[0048] R is preferably a divalent group represented by the general formula (r1):

-CF ₂ -O-(CX ⁶ ₂ ) _e -{O-CF(CF ₃ )} _f -(O) _g - (r1)

where X ⁶ is each independently H, F, or CF ₃ , e is an integer from 0 to 3, f is an integer from 0 to 3, and g is 0 or 1, and more preferably a divalent group, represented by the general formula (r2):

-CF ₂ -O-(CX ⁷ ₂ ) _e -(O) _g - (r2)

where X ⁷ is each independently H or CF ₃ , e is an integer from 0 to 3 and g is 0 or 1,

[0049] Suitable specific examples of R include -CF ₂ -O-CF ₂ -, -CF ₂ -O-, -CF ₂ -O-CF ₂ -, -CF ₂ -O-CF ₂ CF ₂ -, -CF ₂ -O-CF ₂ -, -CF ₂ -O-CF ₂ CF ₂ -, -CF ₂ -O-CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )CF ₂ -, -CF ₂ -O-CF(CF ₃ )CF ₂ -O-, -CF ₂ -O-CF(CF ₃ )CF ₂ -O-CF ₂ - and -CF ₂ -O-CF(CF ₃ )-. In particular, R is preferably a perfluoroalkylene group optionally containing an oxygen atom and in particular -CF ₂ -O-, -CF ₂ -O-CF ₂ -, -CF ₂ -O-CF ₂ CF ₂ -, -CF ₂ -O-CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )CF ₂ - or -CF ₂ -O-CF(CF ₃ )CF ₂ -O- is preferred.

[0050] -R-CZ ¹ Z ² - in the general formula (1) is preferably represented by the general formula (s1):

-CF ₂ -O-(CX ⁶ ₂ ) _e -{O-CF(CF ₃ )} _f -(O) _g -CZ ¹ Z ² - (s1)

where X ⁶ is each, independently, H, F, or CF ₃ , e is an integer from 0 to 3, f is an integer from 0 to 3, g is 0 or 1, and Z ¹ and Z ² are each, independently represents F or CF ₃ . In formula (s1), it is more preferable that one of Z ¹ and Z ² is F and the other is CF ₃ .

[0051] In addition, -R-CZ ¹ Z ² - in the general formula (1) is preferably represented by the general formula (s2):

-CF ₂ -O-(CX ⁷ ₂ ) _e -(O) _g -CZ ¹ Z ² - (s2)

where X ⁷ is each independently H, F or CF ₃ , e is an integer from 0 to 3, g is 0 or 1, and Z ¹ and Z ² are each independently F or CF ₃ . In formula (s2), it is more preferable that one of Z ¹ and Z ² is F and the other is CF ₃ .

[0052] -R-CZ ¹ Z ² - in the general formula (1) is preferably -O-CF ₂ CF ₂ -, -O-CF ₂ CF ₂ CF ₂ -, -O-CF ₂ CF ₂ CF ₂ CF ₂ -, -O-CF ₂ CF(CF ₃ )-O-CF ₂ -, -O-CF ₂ CF(CF ₃ )-O-CF ₂ CF ₂ - _, -CF ₂ -O-CF ₂ - _, - CF ₂ -O-CF(CF ₃ )-, -CF ₂ -OC(CF ₃ ) ₂ -, -CF ₂ -O-CF ₂ -CF ₂ -, -CF ₂ -O-CF ₂ -CF(CF ₃ )-, -CF ₂ -O-CF ₂ -C(CF ₃ ) ₂ -, -CF ₂ -O-CF ₂ CF ₂ -CF ₂ -, -CF ₂ -O-CF ₂ CF ₂ -CF(CF ₃ )-, -CF ₂ -O-CF ₂ CF ₂ -C(CF ₃ ) ₂ -, -CF ₂ -O-CF(CF ₃ )-CF ₂ -, -CF ₂ -O-CF(CF ₃ )- CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )-C(CF ₃ ) ₂ -, -CF ₂ -O-CF(CF ₃ )CF ₂ -CF ₂ -, -CF ₂ -O -CF(CF ₃ )CF ₂ -CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )CF ₂ -C(CF ₃ ) ₂ -, -CF ₂ -O-CF(CF ₃ )CF ₂ -O-CF ₂ -, -CF ₂ -O-CF(CF ₃ )CF ₂ -O-CF(CF ₃ )- or -CF ₂ -O-CF(CF ₃ )CF ₂ -OC(CF ₃ ) ₂ -, more preferably -O-CF ₂ CF ₂ -, -O-CF ₂ CF ₂ CF ₂ -, -O-CF ₂ CF ₂ CF ₂ CF ₂ -, -O-CF ₂ CF(CF ₃ )-O -CF ₂ -, -O-CF ₂ CF(CF ₃ )-O-CF ₂ CF ₂ -, -CF ₂ -O-CF(CF ₃ )-, -CF ₂ -O-CF ₂ -CF(CF ₃ )-, -CF ₂ -O-CF ₂ CF ₂ -CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )-CF(CF ₃ )-, -CF ₂ -O-CF(CF ₃ )CF ₂ -CF(CF ₃ )- or -CF ₂ -O-CF(CF ₃ )CF ₂ -O-CF(CF ₃ )-, and even more preferably -O-CF ₂ CF ₂ - or -O- CF ₂ CF(CF ₃ )-O-CF ₂ CF ₂ -.

[0053] It is also preferable that the polymer (1) is highly fluorinated. For example, 80% or more, 90% or more, 95% or more, or 100% of the C-H bonds in the polymer (1) are preferably replaced by C-F bonds.

[0054] It is also preferred that the monomer (1) and the polymer (1) have C-F bonds and do not have C-H bonds in part excluding -COOM. In other words, in the general formula (1), R represents a perfluoroalkylene group containing 1 or more carbon atoms, and the perfluoroalkylene group may be linear or branched, may be cyclic or acyclic, and may contain at least one catenary heteroatom. The number of carbon atoms of the perfluoroalkylene group can range from 2 to 20 and can range from 4 to 18.

[0055] Monomer (1) and polymer (1) may be partially fluorinated. In other words, it is also preferable that the monomer (1) and the polymer (1) contain at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0056] M represents H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0057] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K or Li are preferred.

[0058] M is H, a metal atom or NR ⁷ ₄ , more preferably H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR ⁷ ₄ , even more preferably H, Na, K, Li or NH ₄ , more preferably H, Na, K or NH ₄ and especially preferably H or NH ₄ .

[0059] It is also preferable that the monomer (1) is a monomer (2) represented by the general formula (2).

It is also preferable that the polymer (1) is a polymer (2) containing a polymerization unit (2) based on a monomer (2) represented by the general formula (2):

CF ₂ =CF(-O-Rf-COOM) (2)

where Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is as described above.

[0060] The polymer (2) may be a homopolymer of the monomer represented by the general formula (2), or may be a copolymer thereof with another monomer.

[0061] In the general formula (2), Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage, or a fluorine alkylene group containing 2 to 100 carbon atoms and a keto group. Rf may contain -CZ ¹ Z ² - (Z ¹ and Z ² as described above) at the termination associated with -COOM. It should be noted that a fluorine-containing alkylene group containing from 2 to 100 carbon atoms and containing an ether bond is an alkylene group that does not contain a structure containing an oxygen atom at the end, and which contains an ether bond between the carbon atoms.

[0062] The fluorine alkylene group for Rf preferably contains 2 or more carbon atoms. Moreover, the number of carbon atoms is 30 or less, more preferably 20 or less, even more preferably 10 or less, and especially preferably 5 or less. Examples of the fluorinated alkylene group include -CF ₂ -, -CF ₂ -, -CF ₂ CF ₂ -, -CF ₂ -, -CF ₂ CF ₂ -, -CF(CF ₃ )-, -CF(CF ₃ )CF ₂ -, -CF(CF ₃ )-, -CF ₂ CF ₂ CF ₂ - and -CF ₂ CF ₂ CF ₂ CF ₂ -. The fluorine-containing alkylene group is preferably a perfluoroalkylene group, and more preferably a linear perfluoroalkylene group.

[0063] The fluorine alkylene group containing an ether linkage preferably contains 3 or more carbon atoms. In addition, the fluorine alkylene group containing an ether linkage preferably contains 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less carbon atoms. It is also preferred that the fluorine alkylene group containing an ether linkage is, for example, a divalent group represented, for example, by the general formula:

where Z ¹ represents F or CF ₃ ; Z ² and Z ³ are each H or F; Z ⁴ represents H, F or CF ₃ ; p1+q1+r1 is an integer from 1 to 10; s1 represents 0 or 1; and t1 is an integer from 0 to 5.

[0064] Specific examples of a fluorine alkylene group containing an ether linkage include -CF(CF ₃ )CF ₂ -O-CF(CF ₃ )-, -(CF(CF ₃ )CF ₂ -O) _n -CF(CF ₃ )- (where n is an integer from 1 to 10), -CF(CF ₃ )CF ₂ -O-CF(CF ₃ )-, -(CF(CF ₃ )CF ₂ -O) _n -CF(CF ₃ )- (where n is an integer from 1 to 10), -CF ₂ CF ₂ O-CF ₂ -, -CF ₂ CF ₂ CF ₂ O-CF ₂ -, -CF ₂ CF ₂ CF ₂ O-CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ O-CF ₂ CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ O-CF ₂ CF ₂ -, -CF ₂ CF ₂ O-CF ₂ - and -CF ₂ CF ₂ O-CF ₂ -. The fluorine alkylene group containing an ether linkage is preferably a perfluoroalkylene group.

[0065] The fluorine alkylene group containing a keto group preferably contains 3 or more carbon atoms. In addition, the number of carbon atoms of the fluorine alkylene group containing the keto group is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less.

[0066] Specific examples of a fluorine alkylene group containing a keto group include -CF ₂ CF(CF ₃ )CO-CF ₂ -, -CF ₂ CF(CF ₃ )CO-CF ₂ CF ₂ -, -CF ₂ CF(CF ₃ )CO-CF ₂ CF ₂ CF ₂ - and -CF ₂ CF(CF ₃ )CO-CF ₂ CF ₂ CF ₂ CF ₂ -. The fluoroalkylene group containing the keto group is preferably a perfluoroalkylene group.

[0067] M represents H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0068] R ⁷ preferably represents an H or C _1-10 organic group, more preferably an H or C _1-4 organic group, and even more preferably an H or C _1-4 alkyl group.

[0069] Examples of the metal atoms include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K or Li are preferred.

[0070] M is preferably H, a metal atom or NR ⁷ ₄ , more preferably H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR ⁷ ₄ , even more preferably H, Na, K, Li or NH ₄ , more preferably H, Na, K or _NH4 , and especially preferably H or _NH4 .

[0071] The monomer represented by the general formula (2) is at least one monomer selected from the group consisting of monomers represented by the general formula (2a), (2b), (2c), (2d), ( 2e), (2f) and (2g):

CF ₂ =CF-O-(CF ₂ ) _n1 -COOM (2a)

where n1 is an integer from 1 to 10 and M is as defined above;

CF ₂ =CF-O-(CF ₂ C(CF ₃ )F) _n2 -COOM (2b)

where n2 is an integer from 1 to 5 and M is as defined above;

CF ₂ =CF-O-(CFX ¹ ) _n3 -COOM (2c)

where X ¹ represents F or CF ₃ , n3 represents an integer from 1 to 10 and M is as defined above;

CF ₂ =CF-O-(CF ₂ CFX ¹ O) _n4 -(CF ₂ ) _n6 -COOM (2d)

where n4 is an integer from 1 to 10, n6 is an integer from 1 to 3, and M is as defined above;

CF ₂ =CF-O-(CF ₂ CF ₂ CFX ¹ O) _n5 -CF ₂ CF ₂ CF ₂ -COOM (2e)

where n5 is an integer from 0 to 10, and M and X ¹ are as defined above;

CF ₂ =CF-O-(CF ₂ ) _n7 -O-(CF ₂ ) _n8 -COOM (2f)

where n7 is an integer from 1 to 10, n8 is an integer from 1 to 3, and M is as defined above; And

CF ₂ =CF[OCF ₂ CF(CF ₃ )] _n9 O(CF ₂ ) _n10 O[CF(CF ₃ )CF ₂ O] _n11 CF(CF ₃ )COOM (2g)

where n9 is an integer from 0 to 5, n10 is an integer from 1 to 8, n11 is an integer from 0 to 5, and M is as defined above.

[0072] In the general formula (2a), n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less.

[0073] Examples of the monomer represented by the general formula (2a) include CF ₂ =CF-O-CF ₂ COOM, CF ₂ =CF(OCF ₂ CF ₂ COOM) and CF ₂ =CF(O(CF ₂ ) ₃ COOM) , where M is as defined above.

[0074] In the general formula (2b), n2 is preferably an integer of 3 or less from the viewpoint of dispersion stability of the resulting composition.

[0075] In the general formula (2c), n3 is preferably an integer of 5 or less in terms of water solubility, and the above-mentioned M is preferably H or _NH4 .

[0076] In the general formula (2d), X ¹ is preferably -CF ₃ from the point of view of dispersion stability of the composition, n 4 is preferably an integer of 5 or less from the point of view of water solubility, and M is preferably H or NH ₄ .

[0077] Examples of the monomer represented by the general formula (2d) include CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ COOM, CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ COOM, and CF ₂ =CFOCF ₂ CF (CF ₃ )OCF ₂ CF ₂ CF ₂ COOM, where M represents H, NH ₄ or an alkali metal.

[0078] In the general formula (2e), n5 is preferably an integer of 5 or less in terms of water solubility, and M is preferably H or NH4 _.

[0079] An example of a monomer represented by the general formula (2e) is CF ₂ =CFOCF ₂ CF ₂ CF ₂ COOM, where M represents H, NH ₄ or an alkali metal.

[0080] In the general formula (2f), n7 is preferably an integer of 5 or less in terms of water solubility, and M is preferably H or NH4 _.

[0081] An example of a monomer represented by the general formula (2f) is CF ₂ =CF-O-(CF ₂ ) ₃ -O-CF ₂ -COOM, where M represents H, NH ₄ or an alkali metal.

[0082] In the general formula (2g), n9 is preferably an integer of 3 or less in terms of water solubility, n10 is preferably an integer of 3 or less, n11 is preferably an integer of 3 or less, and M is preferably H or _NH4 .

[0083] Examples of the monomer represented by the general formula (2g) include CF ₂ =CFO(CF ₂ ) ₂ OCF(CF ₃ )COOM, CF ₂ =CFOCF ₂ CF ₂ OCF(CF ₃ )CF ₂ OCF(CF ₃ )COOM , CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ OCF(CF ₃ )COOM, CF ₂ =CF[OCF ₂ CF(CF ₃ )] ₂ O(CF ₂ ) ₂ O[CF(CF ₃ )CF ₂ O]CF(CF ₃ )COOM, and CF ₂ =CF[OCF ₂ CF(CF ₃ )] ₃ O(CF ₂ ) ₂ O[CF(CF ₃ )CF ₂ O] ₃ CF(CF ₃ )COOM, where M represents H, NH ₄ or an alkali metal.

[0084] The polymer (1) may be a homopolymer containing only a polymerization unit (1), or may be a copolymer containing a polymerization unit (1) and a polymerization unit based on an additional monomer copolymerizable with the monomer (1) represented by the general formula (1). From the point of view of solubility in an aqueous medium, a homopolymer containing only the polymerization unit (1) is preferred. The polymerization units (1) may be the same or different in each case, and the polymer (1) may contain polymerization units (1) based on two or more different monomers represented by the general formula (1).

[0085] The additional monomer is a monomer represented by the general formula CFR=CR ₂ where R independently represents H, F or a perfluoroalkyl group containing from 1 to 4 carbon atoms. It is also preferred that the additional monomer is a fluorine-containing ethylene monomer containing 2 or 3 carbon atoms. Examples of additional monomer include CF ₂ =CF ₂ , CF ₂ =CFCl, =CF ₂ , CFH=, CFH=CF ₂ , CF ₂ =CFCF ₃ , =CFCF ₃ , =CHCF ₃ , CHF=CHCF ₃ (E-form) and CHF=CHCF ₃ (Z-shape).

Among them, from the viewpoint of good copolymerization ability, at least one monomer selected from the group consisting of tetrafluoroethylene (CF ₂ =CF ₂ ), chlorotrifluoroethylene (CF ₂ =CFCl) and vinylidene fluoride (=CF ₂ ) is preferable. , and more preferably at least one monomer selected from the group consisting of tetrafluoroethylene and vinylidene fluoride. Accordingly, the additional monomer polymerization unit is a polymerization unit based on at least one of these monomers selected from the group consisting of tetrafluoroethylene and vinylidene fluoride. The additional monomer polymerization units may be the same or different in each case, and the polymer (1) may contain two or more different additional monomer polymerization units.

[0086] When the polymer (1) contains a polymerization unit (1) and a polymerization unit based on an additional monomer copolymerizable with the monomer (1), the content of the polymerization unit (1) based on the monomer (1) is 40 to 60 mol%, more preferably 45 to 55 mol%, based on all polymerization units constituting the polymer (1), and the polymerization unit content, relative to the additional monomer, is 60 to 40 mol%, more preferably 55 to 45 mol%, based on all units polymerization, making up the polymer (1). This configuration is particularly preferred when the polymerization unit based on the additional monomer copolymerizable with the monomer (1) is a polymerization unit based on a monomer represented by the general formula CFR=CR _2.

[0087] When the polymer (1) contains a polymerization unit (1) and a polymerization unit based on an additional monomer copolymerizable with the monomer (1), the alternation ratio of the polymerization unit (1) and a polymerization unit based on an additional monomer copolymerizable with the monomer (1) , is 40% or more, more preferably 50% or more, even more preferably 60% or more, even more preferably 70% or more, especially preferably 80% or more, and most preferably 90% or more. The alternation ratio can be, for example, from 40 to 99%. Such a configuration is particularly preferred when the polymerization unit based on the additional monomer copolymerizable with the monomer (1) is a polymerization unit based on a monomer represented by the general formula CFR=CR _2,

[0088] The alternation ratio of the polymerization units (1) and the additional monomer-based polymerization units copolymerized with the monomer (1) in the polymer (1) can be determined by ¹⁹ F-NMR analysis of the polymer (1).

[0089] For example, when the monomer (1) is CF ₂ =CFOCF ₂ CF ₂ COOH and the additional monomer is vinylidene fluoride (=CF ₂ ), the alternation ratio of the polymer (1) can be calculated using the following method. The polymer (1) is subjected to ¹⁹ F-NMR measurement, the total integrated value of each of the two peaks appearing in the NMR spectrum is determined, and it is obtained from "OCF ₂ *" CF ₂ =CFOCF ₂ CF ₂ COOH (the peak appearing in the range from - 79 ppm to -83 ppm and the peak appearing from -83 ppm to -87 ppm), and the alternation ratio is calculated according to the following calculation formula:

Alternation ratio (%)≥(b × 2)/(a+b) × 100

a: Total integrated peak value in the region from -79 to -83 ppm.

b: Total integrated peak value in the region from -83 ppm. up to -87 ppm

[0090] Another example of an additional monomer is the monomer represented by the general formula (n1-2):

[0091]

[0092] where X ¹ and X ² are the same or different and each represents H or F; X ³ is H, F, Cl, CF ₃ or CF ₃ ; X ⁴ and X ⁵ are the same or different and each represents H or F; a and c are the same or different and each is 0 or 1; and Rf ³ represents a fluorine-containing alkyl group containing from 1 to 40 carbon atoms, or a fluorine-containing alkyl group containing from 2 to 100 carbon atoms and containing an ether bond.

[0093] Specifically, preferred examples include =CFCF ₂ -O-Rf ³ , CF ₂ =CF-O-Rf ³ , CF ₂ =CFCF ₂ -O-Rf ³ , CF ₂ =CF-Rf ³ , =CH-Rf ³ and =CH-O-Rf ³ , where Rf ³ is the same as in the formula (n1-2) discussed above.

[0094] Another example of an additional monomer is a fluorine acrylate monomer represented by formula (n2-1):

[0095]

[0096] where X ⁹ represents H, F or CF ₃ ; and Rf ⁴ represents a fluorine-containing alkyl group containing from 1 to 40 carbon atoms, or a fluorine-containing alkyl group containing from 2 to 100 carbon atoms and containing an ether bond. Examples of Rf ⁴ group include:

[0097]

where Z ⁸ represents H, F or Cl; d1 is an integer from 1 to 4 and e1 is an integer from 1 to 10,

where e2 represents an integer from 1 to 5,

[0098] where d3 is an integer from 1 to 4, and e3 is an integer from 1 to 10.

[0099] Another example of an additional monomer is a fluorine vinyl ether represented by formula (n2-2):

=CHO-Rf ⁵ (n2-2)

where Rf ⁵ represents a fluorine-containing alkyl group containing from 1 to 40 carbon atoms, or a fluorine-containing alkyl group containing from 2 to 100 carbon atoms and containing an ether bond.

[0100] In particular, preferred examples of the monomer represented by the general formula (n2-2) include:

[0101]

where Z ⁹ represents H or F and e4 represents an integer from 1 to 10,

where e5 represents an integer from 1 to 10,

[0102] where e6 is an integer from 1 to 10.

[0103] More specifically, examples include

[0104]

[0105] and the like.

[0106] In addition, examples also include a fluorinated allyl ether represented by the general formula (n2-3):

=CHO-Rf ⁶ (n2-3)

where Rf ⁶ represents a fluorine-containing alkyl group containing from 1 to 40 carbon atoms or a fluorine-containing alkyl group containing from 2 to 100 carbon atoms and containing an ether linkage, and a fluorine-containing vinyl monomer represented by the general formula (n2-4):

=CH-Rf ⁷ (n2-4)

where Rf ⁷ represents a fluorinated alkyl group containing from 1 to 40 carbon atoms or a fluorinated alkyl group containing from 2 to 100 carbon atoms and containing an ester bond

[0107] Specific examples of monomers represented by the general formulas (n2-3) and (n2-4) include monomers such as

[0108]

[0109] and the like.

[0110] In the polymer (1), the content of the polymerization unit (1) is, in order of increasing preference, 1.0 mol% or more, 3.0 mol% or more, 5.0 mol% or more, 10 mol% or more, 20 % mole or more, 30% mole or more, 40% mole or more, 50% mole or more, 60% mole or more, 70% mole or more, 80% mole or more, or 90% mole or more, relative to to all polymerization links. It is particularly preferable that the content of the polymerization unit (1) is substantially 100 mol%, and most preferably, the polymer (1) contains only the polymerization unit (1).

[0111] In the polymer (1), the content of the polymerization unit based on the additional monomer copolymerizable with the monomer represented by the general formula (1) is, in order of increasing preference, 99.0 mol% or less, 97.0 mol% or less, 95. 0% mole or less, 90% mole or less, 80% mole or less, 70% mole or less, 60% mole or less, 50% mole or less, 40% mole or less, 30% mole or less, 20% mol or less or 10% mol or less with respect to all polymerization units. It is particularly preferable that the content of the additional monomer polymerization unit copolymerizable with the monomer represented by the general formula (1) is substantially 0 mol%, and most preferably, the polymer (1) does not contain the additional monomer polymerization unit.

[0112] The lower limit of the weight average molecular weight (Mw) of the polymer (1) is, in order of increasing preference, 0.2× ¹⁰⁴ or more, 0.4× ¹⁰⁴ or more, 0.6× ¹⁰⁴ or more, 0. 8 × 10 ⁴ or more, 1.0 × 10 ⁴ or more, 1.3 × 10 ⁴ or more, 1.4 × 10 ⁴ or more, 1.5 × 10 ⁴ or more, 1.7 × 10 ⁴ or more than, 1.9 × 10 ⁴ or more, 2.1 × 10 ⁴ or more, 2.3 × 10 ⁴ or more, 2.7 × 10 ⁴ or more, 3.1 × 10 ⁴ or more, 3.5 × 10 ⁴ or more, 3.9 × 10 ⁴ or more, or 4.3 × 10 ⁴ or more. The upper limit of the weight average molecular weight (Mw) of the polymer (1) is, in order of increasing preference, 150.0 × 10 ⁴ or less, 100.0 × 10 ⁴ or less, 60.0 × 10 ⁴ or less, 50.0 × 10 ⁴ or less, or 40.0 × 10 ⁴ or less.

[0113] The lower limit of the number average molecular weight (Mn) of the polymer (1) is, in order of increasing preference, 0.1× ¹⁰⁴ or more, 0.2× ¹⁰⁴ or more, 0.3× ¹⁰⁴ or more, 0. 4 × 10 ⁴ or more, 0.5 × 10 ⁴ or more, 1.0 × 10 ⁴ or more, 1.2 × 10 ⁴ or more, 1.4 × 10 ⁴ or more, 1.6 × 10 ⁴ or more, or 1.8 × 10 ⁴ or more. The upper limit of the number average molecular weight (Mn) of the polymer (1) is, in order of increasing preference, 75.0 × 10 ⁴ or less, 50.0 × 10 ⁴ or less, 40.0 × 10 ⁴ or less, 30.0 × 10 ⁴ or less, or 20.0 × ¹⁰⁴ or less.

[0114] The molecular weight distribution (Mw/Mn) of the polymer (1) is preferably 2.4 or less, more preferably 2.2 or less, even more preferably 2.0 or less, and particularly preferably 1.9 or less.

[0115] Number average molecular weight and weight average molecular weight are molecular weight values calculated by gel permeation chromatography (GPC) using monodisperse polyethylene oxide (PEO) and polyethylene glycol (PEG) as standards. When measurement by GPC is not possible, the number average molecular weight of the polymer (1) can be determined by the correlation between the number average molecular weight calculated from the number of end groups obtained by NMR, FT-IR or the like and the melt flow rate. The melt flow rate can be measured in accordance with JIS K 7210.

[0116] The polymer (1) typically has an end group. The end group is an end group formed during polymerization, and a representative end group is independently selected from hydrogen, iodine, bromine, a linear or branched alkyl group, and a linear or branched fluoroalkyl group, and further, it may optionally contain at least one catenary heteroatom. The alkyl group or fluoroalkyl group preferably contains from 1 to 20 carbon atoms. These end groups are usually formed from the initiator or chain transfer agent used to form the polymer (1), or are generated during the chain transfer reaction.

[0117] The polymer (1) preferably has an ion exchange rate (IXR) of 53 or less. IXR is defined as the number of atoms in the polymer backbone relative to ionic groups. A precursor group that becomes ionic by hydrolysis (eg, -COOCH ₃ ) is not considered an ionic group for purposes of determining IXR.

[0118] IXR is 0.5 or more, more preferably 0.7 or more, even more preferably 1.0 or more, even more preferably 1.2 or more, even more preferably 1.5 or more, and especially preferably 1 .9 or more. In addition, the IXR is more than 30 or less, even more preferably 10 or less, particularly preferably 3 or less, and most preferably 2.2 or less.

[0119] The ion exchange capacity of the polymer (1) is, in order of increasing preference, 0.80 meq/g or more, 1.50 meq/g or more, 1.75 meq/g or more, 2.00 meq/g or more , 2.40 meq/g more or, 2.50 meq/g or more, 2.60 meq/g or more, 3.00 meq/g or more, or 3.50 meq/g or more. The ion exchange capacity represents the content of the ionic group (-COOM) in the polymer (1) and can be determined by calculation from the composition of the polymer (1). A precursor group that becomes ionic by hydrolysis (eg, -COOCH ₃ ) is not considered an ionic group for purposes of determining ion exchange capacity. It is assumed that the higher the ion exchange capacity of the polymer (1), the more anionic groups in the polymer (1), the more stable particles are formed, and also the higher the ability to form particles, which leads to an increase in the number of particles per unit volume of water, and the higher polymerization rate. When the ion exchange capacity of the polymer (1) is too low, the fluorine elastomer produced by polymerization may stick to the polymerization tank, a sufficient polymerization rate may not be achieved, or the amount of fluorine elastomer particles generated may be small.

[0120] In polymer (1), the ionic group (-COOM) is generally distributed along the polymer backbone. The polymer (1) contains a polymer backbone along with a repeating side chain associated with this backbone, and this side chain preferably contains an ionic group.

[0121] The polymer (1) preferably contains an ionic group (-COOM) having a pKa less than 10, and more preferably less than 7.

[0122] The polymer (1) preferably has water solubility. The term "water solubility" refers to the property of being easily dissolved or dispersed in an aqueous medium. When a polymer is water-soluble, its particle size cannot be measured, for example, using dynamic light scattering (DLS). On the other hand, when the polymer is not water-soluble, its particle size can be measured, for example, using dynamic light scattering (DLS).

[0123] The polymer (1) may also be a polymer (12) of a monomer (12) represented by the general formula (12), in which the content of a polymerization unit (12) based on the monomer (12) is 50 mol% or more with respect to all polymerization units constituting the polymer (12), and the weight average molecular weight (Mw) is 1.4 × 10 ⁴ or more. Polymer (12) is a new polymer.

General formula (12): CF ₂ =CF-O-Rf-COOM

wherein X independently represents F or CF ₃ , Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is H , a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0124] Rf and M in the general formula (12) are the same as Rf and M in the general formula (2), representing the monomer of which the polymer (2) is composed.

[0125] The polymer (12) may be a homopolymer containing only a polymerization unit (12) based on a monomer (12), or may be a copolymer containing a polymerization unit (12) and a polymerization unit based on an additional monomer copolymerizable with the monomer (12). 12). The additional monomer is as described above. The polymerization units (12) may be the same or different in each case, and the polymer (12) may contain polymerization units (12) based on two or more different monomers represented by the general formula (12).

[0126] The content of the polymerization unit (12) in the polymer (12) is, in order of increasing preference, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, or 99 mol% or more, based on all polymerization units constituting the polymer (12). It is particularly preferred that the content of the polymerization unit (12) is substantially 100 mol%, and most preferably, the polymer (12) contains only the polymerization unit (12).

[0127] In the polymer (12), the content of the additional monomer polymerization unit copolymerized with the monomer (12) is, in order of increasing preference, 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, 10 mol% or less, or 1 mol% or less, based on all polymerization units constituting the polymer (12). It is particularly preferred that the content of the additional monomer polymerization unit copolymerizable with the monomer (12) is substantially 0 mol%, and most preferably, the polymer (12) does not contain an additional monomer polymerization unit.

[0128] The lower limit of the weight average molecular weight (Mw) of the polymer (12) is, in order of increasing preference, 1.4 x 10 ⁴ or more, 1.7 x 10 ⁴ or more, 1.9 x 10 ⁴ or more, 2. 1 x ¹⁰⁴ or more, 2.3 x ¹⁰⁴ or more, 2.7 x ¹⁰⁴ or more, 3.1 x ¹⁰⁴ or more, 3.5 x ¹⁰⁴ or more, 3.9 x ¹⁰⁴ or more more, 4.3 × 10 ⁴ or more, 4.7 × 10 ⁴ or more, or 5.1 × 10 ⁴ or more. The upper limit of the weight average molecular weight (Mw) of the polymer (12) is, in order of increasing preference, 150.0 × 10 ⁴ or less, 100.0 × 10 ⁴ or less, 60.0 × 10 ⁴ or less, 50.0 × 10 ⁴ or less, or 40.0 × ¹⁰⁴ or less.

[0129] The lower limit of the number average molecular weight (Mn) of the polymer (12) is, in order of increasing preference, 1.0 × 10 ⁴ or more, 1.2 × 10 ⁴ or more, 1.4 × 10 ⁴ or more, 1. 6 × 10 ⁴ or more, or 1.8 × 10 ⁴ or more. The upper limit of the number average molecular weight (Mn) of the polymer (12) is, in order of increasing preference, 75.0 × 10 ⁴ or less, 50.0 × 10 ⁴ or less, 40.0 × 10 ⁴ or less, 30.0 × 10 ⁴ or less, or 20.0 × ¹⁰⁴ or less.

[0130] The molecular weight distribution (Mw/Mn) of the polymer (12) is preferably 3.0 or less, more preferably 2.4 or less, even more preferably 2.2 or less, especially preferably 2.0 or less, and most preferably 1.9 or less.

[0131] Among the polymers (1), the polymer (12) is a new polymer and can be produced by a method (12) for producing a polymer (12) including polymerizing a monomer (12) represented by the general formula (12) in an aqueous medium to obtain a polymer ( 12) from monomer (12), where the oxygen concentration in the polymerization reaction system is maintained at 1500 ppm. volume or less.

[0132] In the production method (12), the oxygen concentration in the polymerization reaction system is 1500 ppm. volume or less. In the production method (12), the oxygen concentration in the reaction system is maintained at 1500 ppmv or less throughout the polymerization of the monomer (12). The oxygen concentration in the reaction system is approximately 500 ppm. volume or less, more preferably about 100 ppm. volume or less and even more preferably reaches 50 ppm. volume or less. The oxygen concentration in the reaction system is typically 0.01 ppm. volume or more.

[0133] In the production method (12), from the viewpoint that the polymer (12) having an even higher molecular weight can be easily obtained, the polymerization temperature of the monomer (12) is 70°C or lower, more preferably 65°C or below, even more preferably 60°C or below, especially preferably 55°C or below, even more preferably 50°C or below, especially preferably 45°C or below, and most preferably 40°C or below, and it is about 10 °C or higher, more preferably 15°C or higher, and even more preferably 20°C or higher.

[0134] In the production method (12), the monomer (12) and the additional monomer described above may be copolymerized.

[0135] In the production method (12), the polymerization pressure is usually from atmospheric pressure to 10 MPa mang. The polymerization pressure is determined accordingly depending on the type of monomer used, the molecular weight of the target polymer and the reaction rate.

[0136] In the production method (12), the polymerization time is generally from 1 to 200 hours, and may be from 5 to 100 hours.

[0137] In the production method (12), the oxygen concentration in the polymerization reaction system can be controlled, for example, by circulating an inert gas such as nitrogen or argon, or, in the case of using a gaseous monomer, the gaseous monomer in the liquid phase or gas phase in the reactor. The oxygen concentration in the polymerization reaction system can be determined by measuring and analyzing the gas leaving the polymerization system gas outlet line using a low concentration oxygen analyzer.

[0138] In the production method (12), the aqueous medium is the reaction medium in which polymerization is carried out, and means a liquid containing water. The aqueous medium may be any medium containing water, and may be a medium containing water and, for example, any of the fluorine-free organic solvents such as alcohols, ethers and ketones, and/or fluorine-containing organic solvents having boiling point 40°C or lower. The aqueous medium is preferably water.

[0139] In the production method (12), polymerization of the monomer can be carried out in the presence of a polymerization initiator. The polymerization initiator is not limited provided that it can generate radicals within the polymerization temperature range described above, and known oil-soluble and/or water-soluble polymerization initiators can be used. A polymerization initiator may be combined with a reducing agent or the like to form a redox agent and initiate polymerization. The concentration of the polymerization initiator is appropriately determined depending on the type of monomer used, the molecular weight of the target polymer and the reaction rate.

[0140] Persulfate (eg, ammonium persulfate) and an organic peroxide such as disuccinic acid peroxide or diglutaric acid peroxide, alone or as a mixture of two or more of them, can be used as the polymerization initiator. Additionally, a polymerization initiator can be used together with a reducing agent such as sodium sulfite to form a redox system. In addition, the concentration of radicals in the system can also be controlled by adding a radical scavenger such as hydroquinone or catechol during polymerization, or by adding a peroxide decomposer such as ammonium sulfite.

[0141] The polymerization initiator is particularly preferably a persulfate, since a polymer having an even higher molecular weight can be easily obtained. Examples of the persulfate include ammonium persulfate, potassium persulfate and sodium persulfate, and ammonium persulfate is preferred.

[0142] The amount of polymerization initiator added is not limited, and the polymerization initiator is added in an amount that does not significantly reduce the polymerization rate (eg, a concentration of several ppm in water) or several times during the initial polymerization stage, either sequentially or continuously. The upper limit is within a range in which the reaction temperature is allowed to increase when heat of the polymerization reaction is removed through the surface of the device, and the upper limit is within the range in which the heat of the polymerization reaction can be removed through the surface of the device.

[0143] In the production method (12), the polymerization initiator can be added at the beginning of the polymerization, and it can also be added during the polymerization. The ratio between the amount of polymerization initiator added when initiating polymerization and the amount of polymerization initiator added during polymerization is from 95/5 to 5/95, more preferably from 60/40 to 10/90, and even more preferably from 30/70 to 15/85. The method of adding the polymerization initiator during polymerization is not limited, and the entire amount may be added at one time, may be added in two or more divided portions, or may be added continuously.

[0144] In the production method (12), from the viewpoint that a polymer having an even higher molecular weight can be easily obtained, the polymerization initiator used for polymerization is added in a total amount of 0.00001 to 10% by weight, relative to aquatic environment. The polymerization initiator used for polymerization is added in a total amount of more than 0.0001 mass% or more, even more preferably 0.001 mass% or more, and especially preferably 0.01 mass% or more, and more preferably 5 mass% or less, and even more preferably 2% by weight or less.

[0145] In the production method (12), from the viewpoint that a polymer having an even higher molecular weight can be easily obtained, the polymerization initiator used for polymerization is added in a total amount of 0.001 to 10% mol per monomer. The polymerization initiator used for polymerization is added in a total amount of more than 0.005 mol% or more, and even more preferably 0.01 mol% or more, and more preferably 5 mol% or less, even more preferably 2.5 mol% or less , particularly preferably 2.2 mol% or less, and most preferably 2.0 mol% or less.

[0146] In the production method (12), from the viewpoint that a monomer containing an even higher molecular weight can be easily obtained, the amount of the monomer containing the monomer (12) present at the initiation of polymerization is 30 mass% or more with respect to to the amount of aqueous medium present. The amount of monomer present is more than 35% by weight or more, and even more preferably 40% by weight or more. The upper limit of the amount of monomer present is not limited, and may be 200 mass% or less from the viewpoint of ensuring smooth polymerization. The amount of monomer present at initiation of polymerization refers to the total amount of monomer (12) and additional monomer, if present, present in the reactor at initiation of polymerization.

[0147] In the production method (12), polymerization can be carried out in the presence of a pH adjuster. The pH adjuster may be added before polymerization is initiated or may be added after polymerization is initiated.

[0148] The pH adjuster may be ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium phosphate, potassium phosphate, sodium citrate, potassium citrate, ammonium citrate, gluconate sodium, potassium gluconate, ammonium gluconate or the like.

[0149] In the production method (12), polymerization of the monomer (12) can be carried out by: loading the reactor with an aqueous medium, monomer (12) and an optional additional monomer and an optional additional additive; mixing the reactor contents; maintaining a given polymerization temperature in the reactor; and then adding a predetermined amount of polymerization initiator to thereby initiate the polymerization reaction. After initiation of the polymerization reaction, a monomer, a polymerization initiator, and an additional additive may be added depending on the purpose.

[0150] In the production method (12), polymerization of the monomer can be carried out substantially in the absence of a fluorine surfactant. The expression "substantially in the absence of fluorosurfactant" as used herein means that the amount of fluorosurfactant is 10 ppm. mass or less relative to the aquatic environment. The amount of fluorine surfactant is 1 ppm. weight or less, reaches more than 100 ppb weight or less, even more preferably 10 ppb weight or less, and more preferably 1 ppb weight or less relative to the aqueous medium.

[0151] In the production method of the present invention, the amount of added polymer (1) is from 0.0001 to 2 mass%, based on 100 mass% of the aqueous medium. When the amount of polymer (1) added (the amount of polymer (1) present) in polymerization is in the above range, the polymerization reaction of the fluorine-containing monomer proceeds smoothly, and a fluorine-containing elastomer can be efficiently produced. When the amount of polymer (1) added is too small, sufficient polymerization speed cannot be achieved or sufficient yield cannot be obtained.

[0152] From the viewpoint of ensuring further smooth progress of the polymerization reaction of the fluorine-containing monomer, the amount of added polymer (1) is more than 0.0005 mass% or more, even more preferably 0.001 mass% or more, especially preferably 0.005 mass% or more, and most preferably 0.01% by weight or more relative to 100% by weight of the aqueous medium.

[0153] On the other hand, when the amount of added polymer (1) is too large, effects corresponding to the amount of added polymer (1) cannot be obtained, which is not economically advantageous. Thus, the amount of added polymer (1) is more than 2 mass% or less, even more preferably 1 mass% or less, and particularly preferably 0.5 mass% or less, based on 100 mass% of the aqueous medium.

[0154] The time for adding polymer (1) during polymerization is not limited, and it can be added before initiation of polymerization or after initiation of polymerization. In addition, the polymer (1) can be added at a time during polymerization at an arbitrary time, or it can be added continuously. Continuous addition of polymer (1) means, for example, adding polymer (1) not all at once, but over a period of time and without interruption or in portions. When polymer (1) is added continuously, it is preferable to add polymer (1) such that the total amount of polymer (1) added is within the range described above. When adding the polymer (1), an aqueous solution containing the polymer (1) and water can be prepared, and the aqueous solution can be added.

[0155] As the polymer (1), an aqueous solution containing polymer (1) can be used.

[0156] Polymer (1) or an aqueous solution containing polymer (1) may contain dimer and trimer of monomer (1) or may be substantially free of dimer and trimer of monomer (1). The dimer and trimer of monomer (1) are typically generated by polymerizing monomer (1) to produce polymer (1). The content of dimer and trimer in the polymer (1) or an aqueous solution containing the polymer (1) is 1.0 wt% or less, preferably 0.1 wt% or less, more than 0.01 wt% or less, even more preferably 0.001 wt% or less, and particularly preferably 0.0001 wt% or less, based on the polymer (1).

[0157] The dimer and trimer content of the polymer (1) or an aqueous solution containing the polymer (1) can be determined by analyzing the polymer (1) using gel permeation chromatography (GPC) and calculating the fraction (area percent) of the dimer peaks and trimer of the total area relative to the total area of all peaks in the chromatogram obtained from GPC analysis.

[0158] Also, when the content of dimer and trimer in the polymer (1) or an aqueous solution containing the polymer (1) is less than 0.5% by weight relative to the polymer (1), it can be determined by measurement using a liquid chromatography method -mass spectrometry (LC/MS).

Specifically, aqueous solutions with five or more different levels of monomer (1) are prepared, aqueous solutions with corresponding levels are analyzed by LC/MS, and the relationship between its level and the area (integrated peak value) corresponding to its level is plotted, to construct a monomer calibration curve (1). Then, from the monomer calibration curve (1), the dimer and trimer calibration curves of monomer (1) are constructed.

Methanol is added to the polymer (1) to prepare the mixture, the mixture is filtered through an ultrafiltration disk (molecular weight cut-off 3000 Da), and the resulting collected liquid is subjected to LC/MS analysis.

Then, using the calibration curve, the area (integrated peak value) of the dimer and trimer of monomer (1) of the chromatogram can be converted into dimer and trimer content.

[0159] The dimer and trimer in the polymer (1) or an aqueous solution containing the polymer (1) can be removed by treating the aqueous solution containing the polymer (1) by at least one method selected from the group consisting of ultrafiltration, microfiltration , dialysis membrane treatment, liquid separation and reprecipitation.

[0160] The production method of the present invention can efficiently produce a fluorine-containing elastomer using at least one type of polymer (1). In addition, in the production method of the present invention, two or more types of polymers (1) can be used simultaneously, or an additional compound having a surfactant function can also be used in combination with them, provided that the compound is volatile or is allowed to remain in a molded article containing a fluorine-containing elastomer.

[0161] In the production method of the present invention, a fluorine-containing monomer is polymerized substantially in the absence of a fluorine-containing surfactant.

[0162] Typically, a fluorine-containing surfactant is used to polymerize the fluorine-containing monomer. However, since the production method of the present invention uses a polymer (1), a fluorine-containing elastomer can be produced by polymerizing a fluorine-containing monomer without using a fluorine-containing surfactant.

[0163] The expression "substantially in the absence of fluorinated surfactant" as used herein means that the content of fluorinated surfactant relative to the aqueous medium is 10 ppm. or less and the fluorine surfactant content is 1 ppb or less, more preferably 100 ppb or less, even more preferably 10 ppb or less, and especially preferably 1 ppb or less.

[0164] The fluorine surfactant may be an anionic fluorine surfactant. A fluorine-containing surfactant is a fluorine-containing surfactant (excluding compounds containing a functional group capable of reacting by radical polymerization and a hydrophilic group).

[0165] The anionic fluorine surfactant may be, for example, a fluorine atom-containing surfactant having the remainder, excluding the anionic group, 20 or fewer carbon atoms in total.

[0166] The fluorine surfactant may also be a fluorine surfactant containing an anionic moiety having a molecular weight of 800 or less.

[0167] "Anionic moiety" means the remainder of the fluorine surfactant excluding the cation. For example, in the case of F(CF ₂ ) _n1 COOM represented by formula (I) described below, the anionic residue is a portion of "F(CF ₂ ) _n1 COO".

[0168] The fluorine surfactant may also be a fluorine surfactant having a LogPOW of 3.5 or less. LogPOW is the partition coefficient between 1-octanol and water, and is represented as LogP, where P is the ratio of the fluorosurfactant concentration in octanol to the fluorosurfactant concentration in water when the octanol/water mixture solution (1: 1), containing a fluorine-containing surfactant, is separated into phases.

[0169] LogPOW is determined by performing HPLC on standard substances with known octanol/water partition coefficients (heptanoic acid, octanoic acid, nonanoic acid and decanoic acid) under the following conditions: column; column TOSOH ODS-120T (diameter 4.6 mm × 250 mm, Tosoh Corporation), eluent; acetonitrile/0.6 wt% HClO ₄ water=1/1 (v/v), flow rate; 1.0 ml/min, sample volume; 300 µl, column temperature; 40°C, detectable radiation: UV 210 nm, plot a calibration curve for each elution time and known octanol/water partition coefficient and calculate the HPLC elution time of the liquid sample based on this calibration curve.

[0170] Specific examples of fluorosurfactant include those described in US Patent Application Publication No. 2007/0015864, US Patent Application Publication No. 2007/0015865, US Patent Application Publication No. 2007/0015866, US Patent Application Publication No. 2007/0015866 No. 2007/0276103, U.S. Patent Application Publication No. 2007/0117914, U.S. Patent Application Publication No. 2007/0142541, U.S. Patent Application Publication No. 2008/0015319, in U.S. Patent No. 3250808, in U.S. Patent No. 3271341, in Patent Laid-Out Japan No. 2003-119204, International Publication No. WO 2005/042593, International Publication No. WO 2008/060461, International Publication No. WO 2007/046377, Japanese Patent Laid-Open No. 2007-119526, International Publication No. WO 2007/046482, International Publication No. WO 2007/046345, US Patent Application Publication No. 2014/0228531, International Publication No. WO 2013/189824, and International Publication No. WO 2013/189826.

[0171] The anionic fluorosurfactant may be a compound represented by the following general formula ( ^N0 ):

X ⁿ⁰ -Rf ⁿ⁰ -Y ⁰ (N ⁰ )

where X ⁿ⁰ represents H, Cl and/or F; Rf ⁿ⁰ is a linear, branched or cyclic alkylene group containing from 3 to 20 carbon atoms in which some or all of the H atoms are replaced by F, where the alkylene group may contain one or more ether linkages and some of the H may be replaced by Cl ; and Y ⁰ represents an anionic group.

[0172] The anionic group Y ⁰ may be -COOM, -SO ₂ M or -SO ₃ M and may be -COOM or -SO ₃ M.

[0173] M represents H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents -H or an organic group.

[0174] The metal atom may be an alkali metal (Group 1) or an alkaline earth metal (Group 2) such as Na, K or Li.

[0175] R ⁷ may be a -H or C1-10 organic group, may be a -H or C1-4 organic group, and may be a -H or C1-4 alkyl group.

[0176] M may be H, a metal atom or NR ⁷ ₄ , may be H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR ⁷ ₄ and may be H, Na, K, Li or _NH4 .

[0177] In Rf ^n0, 50% or more of the H may be replaced by fluorine.

[0178] Examples of the compound represented by the general formula (N ⁰ ) include: the compound represented by the following general formula (N ¹ ):

X ⁿ⁰ -(CF ₂ ) _m1 -Y ⁰ (N ¹ )

where X ⁿ⁰ represents H, Cl, and F, m1 represents an integer from 3 to 15 and Y ⁰ is as defined above; a compound represented by the following general formula (N ² ):

Rf ⁿ¹ -O-(CF(CF ₃ )CF ₂ O) _m2 CFX ⁿ¹ -Y ⁰ (N ² )

where Rf ⁿ¹ represents a perfluoroalkyl group containing from 1 to 5 carbon atoms, m2 represents an integer from 0 to 3, X ⁿ¹ represents F or CF ₃ and Y ⁰ is as defined above; a compound represented by the following general formula (N ³ ):

Rf ⁿ² (CH ₂ ) _m3 -(Rf ⁿ³ ) _q -Y ⁰ (N ³ )

where Rf ⁿ² represents a partially or fully fluorinated alkyl group containing from 1 to 13 carbon atoms and optionally containing an ether bond and/or a chlorine atom, m3 represents an integer from 1 to 3, Rf ⁿ³ represents a linear or branched perfluoroalkylene group, containing from 1 to 3 carbon atoms, q is 0 or 1 and Y ⁰ is as defined above; a compound represented by the following general formula (N ⁴ ):

Rf ⁿ⁴ -O-(CY ⁿ¹ Y ⁿ² ) _p CF ₂ -Y ⁰ (N ⁴ )

where Rf ⁿ⁴ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 to 12 carbon atoms and optionally containing an ether linkage, Y ⁿ¹ and Y ⁿ² are the same or different and each represents H or F, p is 0 or 1 and Y ⁰ is as defined above; and a compound represented by the following general formula ( ^N5 ):

where X ⁿ² , X ⁿ³ and X ⁿ⁴ may be the same or different and each represents H, F or a linear or branched partially or fully fluorinated alkyl group containing from 1 to 6 carbon atoms and optionally containing an ether linkage, Rf ⁿ⁵ represents is a linear or branched partially or fully fluorinated alkylene group containing from 1 to 3 carbon atoms and optionally containing an ether linkage, L is a linking group and Y ⁰ is as defined above, provided that the total number of carbon atoms in X ⁿ² , X ⁿ³ , X ⁿ⁴ and Rf ⁿ⁵ are 18 or less.

[0179] Specific examples of the compound represented by the general formula (N ⁰ ) include perfluorocarboxylic acid (I) represented by the following general formula (I), ω-H perfluorocarboxylic acid (II) represented by the following general formula (II), perfluoroethercarboxylic acid ( III) represented by the following general formula (III), perfluoroalkylalkylenecarboxylic acid (IV) represented by the following general formula (IV), perfluoroalkoxyfluorocarboxylic acid (V) represented by the following general formula (V), perfluoroalkylsulfonic acid (VI) represented by the following general formula ( VI), ω-H perfluorosulfonic acid (VII) represented by the following general formula (VII), perfluoroalkylalkylene sulfonic acid (VIII) represented by the following general formula (VIII), alkylalkylenecarboxylic acid (IX) represented by the following general formula (IX), fluorocarboxylic acid (X) represented by the following general formula (X), an alkoxyfluorosulfonic acid (XI) represented by the following general formula (XI), a compound (XII) represented by the following general formula (XII) and a compound (XIII) represented by the following general formula (XIII ).

Perfluorocarboxylic acid (I) is represented by the following general formula (I):

F(CF ₂ ) _n1 COOM (I)

where n1 is an integer from 3 to 14 and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ is -H or organic group.

[0181] ω-H perfluorocarboxylic acid (II) is represented by the following general formula (II):

H(CF ₂ ) _n2 COOM (II)

where n2 is an integer from 4 to 15 and M is as defined above.

[0182] Perfluoroethercarboxylic acid (III) is represented by the following general formula (III):

Rf ¹ -O-(CF(CF ₃ )CF ₂ O) _n3 CF(CF ₃ )COOM (III)

where Rf ¹ represents a perfluoroalkyl group containing from 1 to 5 carbon atoms, n3 represents an integer from 0 to 3 and M is as defined above.

[0183] Perfluoroalkylalkylenecarboxylic acid (IV) is represented by the following general formula (IV):

Rf ² (CH ₂ ) _n4 Rf ³ COOM (IV)

where Rf ² is a perfluoroalkyl group containing from 1 to 5 carbon atoms, Rf ³ is a linear or branched perfluoroalkylene group containing from 1 to 3 carbon atoms, n4 is an integer from 1 to 3 and M is as defined higher.

[0184] Alkoxyfluorocarboxylic acid (V) is represented by the following general formula (V):

Rf ⁴ -O-CY ¹ Y ² CF ₂ -COOM (V)

where Rf ⁴ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 to 12 carbon atoms and optionally containing an ester bond and/or a chlorine atom, Y ¹ and Y ² are the same or different and each represent H or F and M are as defined above.

[0185] Perfluoroalkylsulfonic acid (VI) is represented by the following general formula (VI):

F(CF ₂ ) _n5 SO ₃ M (VI)

where n5 is an integer from 3 to 14 and M is as defined above.

[0186] ω-H perfluoroalkylsulfonic acid (VII) is represented by the following general formula (VII):

H(CF ₂ ) _n6 SO ₃ M (VII)

where n6 is an integer from 4 to 14 and M is as defined above.

[0187] Perfluoroalkylalkylene sulfonic acid (VIII) is represented by the following general formula (VIII):

Rf ⁵ (CH ₂ ) _n7 SO ₃ M (VIII)

where Rf ⁵ represents a perfluoroalkyl group containing from 1 to 13 carbon atoms, n7 is an integer from 1 to 3 and M is as defined above.

[0188] Alkylalkylenecarboxylic acid (IX) is represented by the following general formula (IX):

Rf ⁶ (CH ₂ ) _n8 COOM (IX)

where Rf ⁶ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 to 13 carbon atoms and optionally containing an ether linkage, n8 is an integer from 1 to 3 and M is as defined above.

[0189] Fluorocarboxylic acid (X) is represented by the following general formula (X):

Rf ⁷ -O-Rf ⁸ -O-CF ₂ -COOM (X)

where Rf ⁷ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 to 6 carbon atoms and optionally containing an ether bond and/or a chlorine atom, Rf ⁸ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 up to 6 carbon atoms, and M is as defined above.

[0190] Alkoxyfluorosulfonic acid (XI) is represented by the following general formula (XI):

Rf ⁹ -O-CY ¹ Y ² CF ₂ -SO ₃ M (XI)

where Rf ⁹ represents a linear or branched partially or fully fluorinated alkyl group containing from 1 to 12 carbon atoms, optionally containing an ether linkage and optionally containing chlorine, Y ¹ and Y ² are the same or different and each represent H or F and M is as defined above.

[0191] Compound (XII) is represented by the following general formula (XII):

where X ¹ , X ² and X ³ are the same or different and each represent H, F, or a linear or branched partially or fully fluorinated alkyl group containing from 1 to 6 carbon atoms and optionally containing an ether linkage, Rf ¹⁰ represents is a perfluoroalkylene group containing from 1 to 3 carbon atoms, L is a linking group and Y ⁰ is an anionic group.

[0192] Y ⁰ may be -COOM, -SO ₂ M or -SO ₃ M and may be -SO ₃ M or -COOM, where M is as defined above.

[0193] Examples of L include a single linkage and a partially or fully fluorinated alkylene group containing from 1 to 10 carbon atoms and optionally containing an ether linkage.

[0194] Compound (XIII) is represented by the following general formula (XIII):

Rf ¹¹ -O-(CF ₂ CF(CF ₃ )O) _n9 (CF ₂ O) _n10 CF ₂ COOM (XIII)

where Rf ¹¹ represents a fluoroalkyl group containing 1 to 5 carbon atoms and containing chlorine, n9 is an integer from 0 to 3, n10 is an integer from 0 to 3, and M is as defined above. Examples of compound (XIII) include CF ₂ ClO(CF ₂ CF(CF ₃ )O) _n9 (CF ₂ O) _n10 CF ₂ COONH ₄ (a mixture having a number average molecular weight of 750, where n9 and n10 are as defined above) .

[0195] The fluorine surfactant may be one type of fluorine surfactant or may be a mixture containing two or more types of fluorine surfactants.

[0196] Examples of the fluorine surfactant include compounds represented by the following formulas. The fluorine surfactant may be a mixture of two or more of these compounds. In one polymerization embodiment, the fluoromonomer is polymerized substantially in the absence of compounds represented by the following formulas:

F(CF ₂ ) ₇ COOM,

F(CF ₂ ) ₅ COOM,

H(CF ₂ ) ₆ COOM,

H(CF ₂ ) ₇ COOM,

CF ₃ O(CF ₂ ) ₃ OCHFCF ₂ COOM,

C ₃ F ₇ OCF(CF ₃ )CF ₂ OCF(CF ₃ )COOM,

CF ₃ CF ₂ CF ₂ OCF(CF ₃ )COOM,

CF ₃ CF ₂ OCF ₂ CF ₂ OCF ₂ COOM,

C ₂ F ₅ OCF(CF ₃ )CF ₂ OCF(CF ₃ )COOM,

CF ₃ OCF(CF ₃ )CF ₂ OCF(CF ₃ )COOM,

CF ₂ ClCF ₂ CF ₂ OCF(CF ₃ )CF ₂ OCF ₂ COOM,

CF ₂ ClCF ₂ CF ₂ OCF ₂ CF(CF ₃ )OCF ₂ COOM,

CF ₂ ClCF(CF ₃ )OCF(CF ₃ )CF ₂ OCF ₂ COOM,

CF ₂ ClCF(CF ₃ )OCF ₂ CF(CF ₃ )OCF ₂ COOM and

where M represents H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0197] In the production method of the present invention, the polymerization of a fluorine-containing monomer can be carried out, for example, by loading the polymer (1) and an aqueous medium into a sealed polymerization tank equipped with a stirrer, deoxygenating the polymerization tank, then loading the monomer, heating the polymerization tank to a predetermined temperature and adding a polymerization initiator to initiate the reaction. The pressure decreases as the reaction progresses, whereby additional monomer is fed continuously or intermittently to maintain the initial pressure, the feed is stopped when a given amount of monomer is supplied, the monomer in the reaction vessel is purged, and the temperature is lowered to room temperature to stop the reaction.

[0198] In the production method of the present invention, polymerization can be carried out in the presence of a polymerization initiator.

[0199] The polymerization initiator may be a radical polymerization initiator. The polymerization initiator is not limited as long as it can generate radicals at the polymerization temperature of the fluorine-containing monomer, and may be, for example, an oil-soluble polymerization initiator, a water-soluble polymerization initiator or an azo compound, but a water-soluble polymerization initiator is preferred. The polymerization initiator may be combined with a reducing agent or the like to serve as a redox initiator.

[0200] The amount of polymerization initiator for polymerizing the fluorine-containing monomer is suitably determined in accordance with the type of monomer used, the molecular weight of the target fluorine-containing elastomer and the reaction rate. The amount of the polymerization initiator is suitably determined according to the molecular weight of the target fluorine-containing elastomer and the rate of the polymerization reaction, and is from 0.00001 to 10% by mass, and preferably is from 0.0001 to 1% by mass, based on the total amount of monomer being 100 % wt.

[0201] The polymerization initiator may be an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator.

[0202] The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, and representative examples include dialkyl peroxycarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate; peroxyethers such as tert-butylperoxyisobutyrate and tert-butylperoxypivalate; and dialkyl peroxides, such as di-tert-butyl peroxide, as well as di[perfluoro(or fluorochloro)acyl]peroxides, such as di(ω-hydro-dodecafluorohexanoyl) peroxide, di(ω-hydrotetradecafluoroheptanoyl) peroxide, di(ω-hydrohexadecafluorononanoyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluorovaleryl) peroxide, di(perfluorohexanoyl) peroxide, di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide, di(perfluorononanoyl) peroxide, di(ω-chlorohexafluorobutyryl) peroxide, di(ω- chlorodecafluorohexanoyl)peroxide, di(ω-chloro-tetradecafluorohexanoyl)peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexadecafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chlorodecafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl -peroxide, di(dichloropentafluorobutanoyl) peroxide, di(trichlorooctafluorohexanoyl) peroxide, di(tetrachloroondefluorooctanoyl) peroxide, di(pentachlorotetradecafluorodecanoyl) peroxide and di(undecachlorodothoriacontafluorodocosanoyl) peroxide.

[0203] Examples of the azo compound include azodicarboxylate, azodicarboxydiamide, 2,2'-azobisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride and 4,4'- azobis(4-cyanovaleric acid).

[0204] The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples thereof include ammonium salts, potassium salts and sodium salts of persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, percarbonic acid and the like, organic peroxides such as peroxide disuccinic acid and diglutaric acid peroxide, tert-butyl permaleate and tert-butyl hydroperoxide. A reducing agent such as sulfite may be included with them, and its amount may be 0.1 to 20 times different from the amount of peroxide.

[0205] The water-soluble peroxide is a salt of persulfuric acid, since the amount of radicals generated can be easily controlled, and potassium persulfate (K ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), and sodium persulfate (Na ₂ S ₂ O ₈ ) are preferred, and ammonium persulfate is most preferred.

[0206] When polymerization is carried out using a water-soluble peroxide at a polymerization temperature of 45°C or higher, it is preferable that no reducing agent is used.

[0207] For example, when polymerization is carried out at a low temperature, 60°C or lower, the polymerization initiator used is a redox initiator obtained by combining an oxidizing agent and a reducing agent. In other words, polymerization occurs in the presence of a redox initiator.

[0208] Examples of the oxidizing agent include persulfates, organic peroxides, potassium permanganate, manganese triacetate, cerium ammonium nitrate and bromates. Examples of the reducing agent include sulfites, bisulfites, bromates, diimine, oxalic acid and sulfinic acid metal salts. Examples of persulfates include ammonium persulfate, potassium persulfate and sodium persulfate. Examples of sulfites include sodium sulfite and ammonium sulfite. To increase the decomposition rate of the initiator, a copper salt or an iron salt is preferably also added to the redox initiator combination. The copper salt may be copper(II) sulfate and the iron salt may be iron(II) sulfate. When a copper salt or an iron salt is used, it is especially preferable to add a chelating agent. The chelating agent is disodium ethylenediaminetetraacetate dihydrate.

[0209] Examples of the redox initiator include potassium permanganate/oxalic acid, ammonium persulfate/bisulfite/iron(II) sulfate, ammonium persulfate/sulfite/iron(II) sulfate, ammonium persulfate/sulfite, ammonium persulfate/sulfate/ferrous sulfate ( II), manganese triacetate/oxalic acid, ammonium cerium nitrate/oxalic acid, bromate/sulfite, bromate/bisulfite and ammonium persulfate/sodium hydroxymethanesulfinate dihydrate and ammonium persulfate/sodium hydroxymethanesulfinate dihydrate are preferred.

[0210] When a redox initiator is used, one of the oxidizing agent and the reducing agent may be loaded into the polymerization tank in advance, after which the other is added continuously or periodically to initiate polymerization. For example, when using ammonium persulfate/sodium hydroxymethanesulfinate dihydrate, ammonium persulfate is preferably charged into a polymerization tank, and then sodium hydroxymethanesulfinate dihydrate is continuously added thereto.

[0211] The amount of persulfate used in the redox initiator is from 0.001 to 2.0% by mass, more preferably from 0.01 to 1.5% by mass, and especially preferably from 0.05 to 1.0% by mass, based on to the aqueous medium used in polymerization.

[0212] The amount of reducing agent used is 1 to 30% by weight, more preferably 3 to 25% by weight, and particularly preferably 5 to 20% by weight, based on the aqueous medium used in the polymerization.

[0213] The amount of the third component (such as the above copper salt or iron salt) used is from 0.001 to 0.5 mass%, more preferably from 0.005 to 0.4 mass%, and especially preferably from 0.01 to 0.3 % mass relative to the aqueous medium used in polymerization.

[0214] In the production method of the present invention, the fluorine-containing monomer can also be polymerized in the presence of a chain transfer agent. The chain transfer agent may be a known chain transfer agent, for example, a hydrocarbon, an ester, an ether, an alcohol, a ketone, a halogen-containing compound, a carbonate and the like. In particular, isopentane, diethyl malonate and ethyl acetate are preferred from the point of view of reducing the likelihood of a decrease in the reaction rate, and diiodine compounds such as I(CF ₂ ) ₄ I, I(CF ₂ ) ₆ I and II are preferred from the point of view that they can iodize the end portions of the polymer, and the resulting polymer can be used as a reactive polymer.

[0215] The chain transfer agent used is particularly preferably a bromine compound or an iodine compound. The polymerization method using a bromine compound or an iodine compound is, for example, iodine transfer polymerization or bromine transfer polymerization.

[0216] The iodine compound and bromine compound are insoluble in water and are less likely to emulsify. Accordingly, their use in emulsion polymerization is usually limited and there is a tendency to use large amounts of surfactant. According to the production method of the present invention, the fluorine-containing elastomer can be produced by polymerization using an iodine compound or bromine compound, such as iodine transfer polymerization or bromine transfer polymerization, even in the absence of a commonly used surfactant.

[0217] Iodine transfer polymerization refers to a process involving living radical polymerization by a radical catenary reactivation mechanism, which is radically active due to the low dissociation energy of the carbon-iodine bond and occurs due to the involvement of a chain transfer reaction during the radical polymerization reaction. Known reaction conditions can be suitably used, and, for example, the reaction conditions described, but not limited to, in "KOBUNSHI RONBUNSHU (Japanese Journal of Polymer Science and Technology), Vol. 49, No. 10, pp. 765-783, October 1992", in Japanese Patent Laid-Open No. 53-3495, and the like, such polymerization can be carried out using a bromine compound instead of an iodine compound, and such polymerization is called bromine transfer polymerization herein.

[0218] Among them, iodine transfer polymerization is preferable from the viewpoint of polymerization reactivity, cross-linking reactivity and the like.

[0219] Typical examples of a bromine compound or an iodine compound include compounds represented by the general formula:

R ⁸ I _x Br _y

where each x and y is an integer from 0 to 2 and satisfies the condition 1≤x+y≤2, and R ⁸ represents a saturated or unsaturated hydrofluorocarbon group or a chlorofluorocarbon group containing from 1 to 16 carbon atoms, or a hydrocarbon group, containing from 1 to 3 carbon atoms, which may contain an oxygen atom. Iodine or bromine is introduced into the polymer using a bromine compound or iodine compound and acts as a cross-linking point.

[0220] Examples of the bromine compound and the iodine compound include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4-dichloroperfluoropentane, 1, 6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorodecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoperfluorohexane, 1,3-diiodo-n-propane, CF ₂ Br ₂ , BrCF ₂ CF ₂ Br , CF ₃ CFBrCF ₂ Br, CFClBr ₂ , BrCF ₂ CFClBr, CFBrClCFClBr, BrCF ₂ CF ₂ CF ₂ Br, BrCF ₂ CFBrOCF ₃ , 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4 -iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene-1,2-bromo-4-iodoperfluorobutene-1 and monoiodomonobromine substituted product, diiodomonobromine substituted product and (2-iodoethyl) and (2-bromoethyl) substituted product benzene, and these compounds can be used alone or in combination of two or more of them. Among them, from the viewpoint of polymerization reactivity, cross-linking reactivity, availability and the like, compounds that do not contain bromine and contain only iodine are preferred, and 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane are preferably used or 2-iodoperfluoropropane.

[0221] The amount of the chain transfer agent is 0.2×10 ^-3 to 2% mol, and more preferably 1.0×10 ^-3 to 1% mol, based on the total amount of monomer used in the polymerization.

[0222] Aqueous medium means a liquid containing water. The aqueous medium is not limited as long as it contains water and may be a medium containing water and, for example, a fluorine-free organic solvent such as an alcohol, ether or ketone, and/or a fluorine-containing organic solvent with a boiling point of 40° C. or lower.

[0223] When polymerizing a fluorine-containing monomer, a phosphoric acid salt, sodium hydroxide, potassium hydroxide, ammonia and the like can be used as a pH adjuster.

[0224] The aqueous medium is preferably acidic. By polymerizing the fluorine-containing monomer in the presence of the polymer (1) using an acidic aqueous medium, more fluorine-containing polymer particles can be produced at a higher polymerization rate, and the adhesion of the fluorine-containing polymer in the polymerization tank is further suppressed. The pH of the aqueous medium is preferably 7 or lower, and more preferably 6 or lower, and preferably 3 or higher.

[0225] In the production method of the present invention, the fluorine-containing monomer can be polymerized in the presence or absence of seeds for polymerizing the fluorine-containing monomer.

[0226] "Seed particles for the polymerization of fluorine-containing monomer" are obtained by polymerizing the fluorine-containing monomer in an aqueous medium, and they must be present during the second polymerization, in which the types of components, such as the monomer and the additive (for example, a polymerization initiator) constituting the polymerization reaction system , the proportions of components present, reaction conditions, and the like, differ from the first. The fluorine-containing monomer polymerization seed particles act as so-called seeds during the polymerization of the fluorine-containing monomer and represent the polymerization of the fluorine-containing monomer in the presence of the seed particles, that is, seed polymerization. The production method of the present invention may be a method in which such seed polymerization is not carried out when the fluorine-containing monomer is polymerized.

[0227] In the production method of the present invention, the polymerization temperature of the fluorine-containing monomer is preferably 10 to 120°C, and more preferably 20 to 100°C. From the point of view of stability of the aqueous dispersion and reduction of the adhesion fraction, the polymerization temperature is from 15 to 60°C, from 18 to 55°C, and even more preferably from 20 to 50°C. Moreover, from the point of view that the polymerization rate is increased and, furthermore, a fluorine-containing elastomer can be obtained imparting excellent physical properties to the molded article, the polymerization temperature is preferably 60 to 120°C, more preferably 60 to 100°C, and even more preferably from 70 to 90°C.

[0228] In the production method of the present invention, the polymerization pressure for polymerizing the fluorine-containing monomer is preferably 0.5 to 10 MPa g, and even more preferably 1 to 7 MPa g.

[0229] In the production method of the present invention, since the fluorine-containing monomer is polymerized in the presence of the polymer (1) and the aqueous medium, the adhesion of the polymer (fluorine-containing elastomer) in the polymerization tank can be suppressed. The adhesion ratio of the polymer in the polymerization tank is preferably 8 wt% or less, more preferably 4 wt% or less, even more preferably 3 wt% or less, and most preferably 2 wt% or less.

[0230] The polymer adhesion ratio is the ratio (adhesion ratio in the polymerization tank) of the mass of polymer deposits adhered in the polymerization tank after completion of polymerization to the total amount of polymer (fluorinated elastomer) after completion of polymerization. Polymer deposits include polymer adhering to the interior of the polymerization tank, such as the inner wall of the polymerization tank and the stirrer blades, after removing the aqueous dispersion from the polymerization tank after completion of polymerization, as well as polymer released from the aqueous dispersion that floats or settles due to aggregation, not dispersing in an aqueous dispersion. The mass of the polymer deposits is the mass after the water contained in the polymer deposits has been removed by drying at 120°C.

Polymer adhesion fraction (% mass) = mass of polymer deposits / mass of resulting polymer (including deposits) × 100

Mass of polymer produced = Mass of aqueous dispersion × Solids concentration (% wt) of aqueous dispersion/100 + Mass of polymer deposits

[0231] In the production method of the present invention, an aqueous dispersion of a fluorine-containing elastomer is produced by polymerizing a fluorine-containing monomer. The fluorine-containing monomer preferably does not contain a hydrophilic group.

[0232] Examples of the fluorine-containing monomer include fluorine-containing monomers such as vinylidene fluoride (VdF), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro(alkyl vinyl ether) (PAVE), chlorotrifluoroethylene (CTFE), trifluoroethylene, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, ten , tetrafluoroisobutene, hexafluoroisobutene, vinyl fluoride, iodine vinyl fluoride ether and fluorine monomer (2), represented by the general formula (2):

CHX ¹ =CX ² Rf (2)

where one of X ¹ and X ² represents H, the other represents F, and Rf represents a linear or branched fluoroalkyl group containing from 1 to 12 carbon atoms.

[0233] PAVE is more preferably perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE) or perfluoro(propyl vinyl ether) (PPVE), and particularly preferably PMVE.

[0234] PAVE may be a perfluorovinyl ether represented by the formula: CF ₂ =CFOCF ₂ ORf ^c where Rf ^c is a linear or branched perfluoroalkyl group containing from 1 to 6 carbon atoms, a cyclic perfluoroalkyl group containing from 5 to 6 carbon atoms, or a linear or branched perfluorooxyalkyl group containing from 1 to 3 oxygen atoms and from 2 to 6 carbon atoms. PAVE is preferably, for example, CF ₂ =CFOCF ₂ OCF ₃ , CF ₂ =CFOCF ₂ OCF ₂ CF ₃ or CF ₂ =CFOCF ₂ OCF ₂ CF ₂ OCF ₃ .

[0235] The fluorine-containing monomer (2) is preferably a monomer in which Rf is a linear fluoroalkyl group, and more preferably is a monomer in which Rf is a linear perfluoroalkyl group. Rf preferably contains from 1 to 6 carbon atoms.

[0236] Examples of fluorine-containing monomer (2) include =CFCF ₃ , =CFCF ₂ CF ₃ , =CFCF ₂ CF ₂ CF ₃ , =CFCF ₂ CF ₂ CF ₂ CF ₃ , CHF=CHCF ₃ (1,3,3,3 -tetrafluoropropene), CHF=CHCF ₃ (E form) and CHF=CHCF ₃ (Z form) and in particular 2,3,3,3-tetrafluoropropylene represented by the formula =CFCF ₃ is preferred.

[0237] In the production method of the present invention, at least vinylidene fluoride or tetrafluoroethylene is preferably polymerized as a fluorine-containing monomer, and vinylidene fluoride is more preferably polymerized because more fluorine-containing elastomer particles can be produced at a higher polymerization rate, while adhesion of the fluorine-containing elastomer in the polymerization tank is further suppressed.

[0238] In the production method of the present invention, the fluorine-free monomer can be polymerized together with the fluorine-containing monomer. Examples of the fluorine-free monomer include α-olefin monomers containing 2 to 10 carbon atoms, such as ethylene, propylene, butene and pentene, and alkyl vinyl ethers containing an alkyl group containing 1 to 20 carbon atoms, such as methyl vinyl ether ether, ethyl vinyl ether, propyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether and butyl vinyl ether, and one or a combination of two or more of these monomers and compounds may be used.

[0239] The production method of the present invention produces an aqueous dispersion containing a fluorine-containing elastomer. The fluorine-containing elastomer is preferably a partially fluorinated elastomer because the polymerization of the fluorine-containing monomer proceeds more smoothly and more particles of the fluorine-containing elastomer can be produced at a higher polymerization rate, while the adhesion of the fluorine-containing elastomer in the polymerization tank is further suppressed. A partially fluorinated elastomer is a fluoropolymer that contains a fluorine-containing monomer unit in which the content of the perfluoromonomer unit is less than 90 mol% relative to the total monomer units, and which has a glass transition temperature of 20°C or lower and a peak melting value (ΔH) of 4.5 J/g or less.

[0240] The fluorine-containing elastomer preferably contains a methylene group (-CH ₂ -) in the main chain. The fluorine-containing elastomer (partially fluorinated elastomer) containing -CH ₂ - in the main chain is not limited to as long as it contains the chemical structure represented by -CH ₂ -, examples thereof include fluorine-containing elastomers containing a structure such as -CH ₂ -CF ₂ - , -CH ₂ -CH(CH ₃ )-, -CH ₂ -CH ₂ - or -CH ₂ CF(CF ₃ )-, and they can be introduced into the backbone of the fluorine-containing elastomer by polymerization of, for example, vinylidene fluoride, propylene, ethylene and 2,3,3,3-tetrafluoropropylene. The tetrafluoroethylene unit content of the fluorine-containing elastomer (the content of tetrafluoroethylene-based monomer unit relative to all monomer units of the fluorine-containing elastomer) may be less than 40 mol%.

[0241] The fluorine-containing elastomer preferably contains a monomer unit based on at least one monomer selected from the group consisting, for example, of tetrafluoroethylene (TFE), vinylidene fluoride (VdF) and a perfluoroethylene-unsaturated compound (such as hexafluoropropylene (HFP) or perfluoro(alkyl vinyl ether) (PAVE)), represented by the general formula: CF ₂ =CF-Rf ^a , where Rf ^a represents -CF ₃ or -ORf ^b (Rf ^b represents a perfluoroalkyl group containing from 1 to 5 carbon atoms ). The fluorine-containing elastomer preferably contains a VdF unit or, in particular, a TFE unit.

[0242] More specific examples of fluorine-containing elastomer include VdF-based fluorine-elastomer, TFE/propylene (Pr)-based fluorine-elastomer, TFE/Pr/VdF-based fluorine-elastomer, ethylene (Et)/HFP-based fluorine-elastomer, based on Et/HFP/VdF, fluorinated elastomer based on Et/HFP/TFE and fluorinated elastomer based on Et/TFE/PAVE. Among them, VdF based fluorine elastomer, TFE/Pr based fluorine elastomer, TFE/Pr/VdF based fluorine elastomer or Et/TFE/PAVE based fluorine elastomer is more suitable for use in terms of good heat aging resistance and oil resistance.

[0243] The VdF-based fluorine elastomer is a fluorine elastomer having a VdF unit. The VdF-based fluorine-containing elastomer preferably contains a VdF unit accounting for 20 mol% or more and 90 mol% or less, more preferably 40 mol% or more and 85 mol% or less, even more than the observed 45 mol% or more and 80% mol or less and especially preferably 50 mol% or more and 80 mol% or less of the total number of moles of the VdF unit and the monomer unit based on the additional monomer.

[0244] The additional monomer in the VdF-based fluorine-containing elastomer is not limited as long as it is a monomer copolymerizable with VdF, and, for example, the fluorine-containing monomer described above can be used.

[0245] The VdF-based fluorine-containing elastomer is at least one copolymer selected from the group consisting of VdF/HFP copolymer, VdF/TFE/HFP copolymer, VdF/CTFE copolymer, VdF/CTFE/TFE copolymer, VdF copolymer /PAVE, VdF/TFE/PAVE copolymer, VdF/HFP/PAVE copolymer, VdF/HFP/TFE/PAVE copolymer, VdF/TFE/Pr copolymer, VdF/Et/HFP copolymer and VdF/fluorine monomer copolymer (2). The VdF-based fluorine-containing elastomer more preferably contains, as an additional monomer other than VdF, at least one monomer selected from the group consisting of TFE, HFP and PAVE.

[0246] Among these VdF-based fluorine-containing elastomers, at least one copolymer selected from the group consisting of VdF/HFP copolymer, VdF/TFE/HFP copolymer, VdF/fluorine-containing monomer copolymer (2), VdF/PAVE copolymer, VdF/TFE/PAVE copolymer, VdF/HFP/PAVE copolymer and VdF/HFP/TFE/PAVE copolymer is preferred, and at least one copolymer selected from the group consisting of VdF/HFP copolymer, VdF/HFP copolymer /TFE, a VdF/fluorine-containing monomer copolymer (2) and a VdF/PAVE copolymer is more preferred.

[0247] The VdF/PAVE copolymer preferably contains a VdF/PAVE composition of (65 to 90)/(35 to 10) (% mol).

In one preferred form, the VdF/PAVE composition is (50 to 78)/(50 to 22) (% mol).

[0248] The VdF/TFE/PAVE copolymer preferably contains a composition of VdF/TFE/PAVE (40 to 80)/(3 to 40)/(15 to 35) (% mol).

[0249] The VdF/HFP/PAVE copolymer preferably contains a composition of VdF/HFP/PAVE (65 to 90)/(3 to 25)/(3 to 25) (% mol).

[0250] The VdF/HFP/TFE/PAVE copolymer preferably contains a composition of VdF/HFP/TFE/PAVE (40 to 90)/(0 to 25)/(0 to 40)/(3 to 35) (% mol), and more preferably (40 to 80)/(3 to 25)/(3 to 40)/(3 to 25) (% mol).

[0251] The VdF copolymer/fluorine-containing monomer (2) is preferably a copolymer in which the % molar ratio of the VdF unit/fluorine-containing monomer (2) is (85 to 20)/(15 to 80) and an additional monomer unit other than VdF and fluorine-containing monomer (2) is 0 to 50 mol% of the total monomer units, and the mole % ratio of VdF unit/fluorine-containing monomer (2) is more preferably (80 to 20)/(20 to 80). In one preferred form, the composition of VdF unit/fluorine-containing monomer (2) is (78 to 50)/(22 to 50) (% mol).

[0252] Also, the VdF copolymer/fluorine-containing monomer (2) is preferably a copolymer in which the mole % ratio of the VdF unit/fluorine-containing monomer (2) is (85 to 50)/(15 to 50), and the additional monomer unit , different from VdF and fluorine-containing monomer (2), ranges from 1 to 50% mol of all monomer units. In addition, monomers other than VdF and fluorine-containing monomer (2) are preferably monomers provided as additional monomers to the VdF-based fluorine-containing elastomer, such as TFE, HFP, PMVE, perfluoroethyl vinyl ether (PEVE), PPVE , CTFE, trifluoroethylene, hexafluoroisobutene, vinyl fluoride, Et, Pr, alkyl vinyl ether and a monomer that provides a cross-linkable group, and in particular PMVE, CTFE, HFP and TFE are more preferred.

[0253] TFE/Pr fluorine elastomer refers to a fluorine copolymer containing 45 to 70 mol% TFE and 55 to 30 mol% Pr. In addition to these two components, a specific third component may be included.

[0254] The particular third component contained may be, for example, a fluorine-containing monomer, such as a fluorine-containing olefin other than TFE (such as VdF, HFP, CTFE or perfluoro(butylethylene)), fluorovinyl ether, perfluoropropylvinyl ether ) or perfluoro(methyl vinyl ether)); or a hydrocarbon-based monomer such as an α-olefin (such as ethylene or 1-butene), a vinyl ether (such as ethyl vinyl ether, butyl vinyl ether, or hydroxybutyl vinyl ether), or a vinyl ester (such as vinyl acetate, vinyl benzoate, vinyl crotonate or vinyl methacrylate). With regard to the specific third component, one component or a combination of two or more of them can be used.

[0255] The TFE/Pr based fluorine elastomer preferably contains VdF, and among TFE/Pr based fluorine elastomers, an elastomer containing TFE, Pr and VdF is referred to as a TFE/Pr/VdF based fluorine elastomer.

[0256] The TFE/Pr/VdF-based fluorine-containing elastomer may further comprise the above-mentioned specific third component other than VdF. With respect to the specific third component, one or a combination of two or more components may be used. The total content of the third component in the TFE/Pr fluorine-containing elastomer is preferably 35 mol% or less, more preferably 33 mol% or less, and even more preferably 31 mol% or less.

[0257] The Et/HFP copolymer preferably contains a composition of Et/HFP (35 to 80)/(65 to 20) (mol%), and more preferably (40 to 75)/(60 to 25) (mol% ).

[0258] The Et/HFP/TFE copolymer preferably contains a composition of Et/HFP/TFE (35 to 75)/(25 to 50)/(0 to 15) (% mol), and more preferably (45 to 75 ) /(25 to 45)/(0 to 10) (% mol).

[0259] The Et/TFE/PAVE copolymer preferably contains a composition of Et/TFE/PAVE (10 to 40)/(32 to 60)/(20 to 40) (% mol), and more preferably (20 to 40 )/(40 to 50)/(20 to 30) (% mol). PAVE is PMVE.

[0260] The fluorine-containing elastomer is preferably a fluorine-containing elastomer containing a VdF unit, and more preferably a VdF/HFP copolymer or a VdF/HFP/TFE copolymer, and the fluorine-containing elastomer having a VdF/HFP/TFE composition (32 to 85)/( 10 to 34)/(0 to 40) (% mol) is particularly preferred. The VdF/HFP/TFE composition is more preferably (32 to 85)/(15 to 34)/(0 to 34) (mol%), and even more preferably (47 to 81)/(17 to 32) /(0 to 26) (% mol).

[0261] For example, the VdF/HFP copolymer preferably has a composition of VdF/HFP (45 to 85)/(15 to 55) (% mol), more preferably (50 to 83)/(17 to 50) (% mol). mol), even more preferably (55 to 81)/(19 to 45) (% mol), and especially preferably (60 to 80)/(20 to 40) (% mol).

[0262] The configuration described above is the configuration of the main monomers of the fluorine-containing elastomer, and the monomer that provides the cross-linkable group can be copolymerized in addition to the main monomers. A monomer that forms a cross-linkable group is a monomer capable of introducing into a fluorine-containing elastomer a cross-linkable group suitable according to the production method and cross-linking system, and examples include known polymerizable compounds containing a cross-linkable group such as iodine atom, bromine atom , carbon-carbon double bond, cyano group, carboxyl group, hydroxyl group, amino group or ester group.

[0263] Preferable examples of the monomer that provides the cross-linkable group include compounds represented by the general formula (3):

CY ¹ ₂ =CY ² R _f ² X ¹ (3)

where each of Y ¹ and Y ² independently represents a fluorine atom, a hydrogen atom or -CF ₃ ; Rf ² is a linear or branched fluorine-containing alkylene group which may contain one or more oxygen atoms linked by an ether bond, which may contain an aromatic ring and in which some or all of the hydrogen atoms are replaced by fluorine atoms; and X ¹ represents an iodine atom or a bromine atom.

[0264] Specific examples of the monomer that provides the cross-linkable group include iodine- or bromine-containing monomers represented by the general formula (4):

CY ¹ ₂ =CY ² R _f ³ CHR ¹ -X ¹ (4)

where Y ¹ , Y ² and X ¹ are as described above; Rf ³ is a linear or branched fluorine alkylene group which may contain one or more oxygen atoms linked by an ether bond and in which some or all of the hydrogen atoms are replaced by fluorine atoms, that is, a linear or branched fluorinated alkylene group in which some or all hydrogen atoms are replaced by fluorine atoms, a linear or branched fluorine-containing oxyalkylene group in which some or all of the hydrogen atoms are replaced by fluorine atoms, or a linear or branched fluorine-containing polyoxyalkylene group in which some or all of the hydrogen atoms are replaced by fluorine atoms; and R ¹ represents a hydrogen atom or a methyl group, and

iodine- or bromine-containing monomers, represented by general formulas (5) - (22):

CY ⁴ ₂ =CY ⁴ (CF ₂ ) _n -X ¹ (5)

where Y ⁴ s are the same or different and each represent a hydrogen atom or a fluorine atom, and n is an integer from 1 to 8,

CF ₂ =CFCF ₂ R _f ⁴ -X ¹ (6)

where R ⁴ represents -(OCF ₂ ) _n - or -(OCF(CF ₃ )) _n -, and n represents an integer from 0 to 5,

CF ₂ =CFCF ₂ (OCF(CF ₃ )CF ₂ ) _m (OCF ₂ CF ₂ ) _n OCF ₂ -X ¹ (7)

where m is an integer from 0 to 5, and n is an integer from 0 to 5,

CF ₂ =CFCF ₂ (OCF ₂ CF ₂ ) _m (OCF(CF ₃ )CF ₂ ) _n OCF(CF ₃ )-X ¹ (8)

where m is an integer from 0 to 5, and n is an integer from 0 to 5,

CF ₂ =CF(OCF ₂ CF(CF ₃ )) _m O(CF ₂ ) _n -X ¹ (9)

where m is an integer from 0 to 5, and n is an integer from 1 to 8,

CF ₂ =CF(OCF ₂ CF(CF ₃ )) _m -X ¹ (10)

where m is an integer from 1 to 5,

CF ₂ =CFOCF ₂ (CF(CF ₃ )OCF ₂ ) _n CF(-X ¹ )CF ₃ (11)

where n is an integer from 1 to 4,

CF ₂ =CFO(CF ₂ ) _n OCF(CF ₃ )-X ¹ (12)

where n is an integer from 2 to 5,

CF ₂ =CFO(CF ₂ ) _n -(C ₆ H ₄ )-X ¹ (13)

where n is an integer from 1 to 6,

CF ₂ =CF(OCF ₂ CF(CF ₃ )) _n OCF ₂ CF(CF ₃ )-X ¹ (14)

where n is an integer from 1 to 2,

=CFCF ₂ O(CF(CF ₃ )CF ₂ O) _n CF(CF ₃ )-X ¹ (15)

where n is an integer from 0 to 5,

CF ₂ =CFO(CF ₂ CF(CF ₃ )O) _m (CF ₂ ) _n -X ¹ (16)

where m is an integer from 0 to 5, and n is an integer from 1 to 3,

=CFCF ₂ OCF(CF ₃ )OCF(CF ₃ )-X ¹ (17)

=CFCF ₂ OCF ₂ -X ¹ (18)

CF ₂ =CFO(CF ₂ CF(CF ₃ )O) _m CF ₂ CF(CF ₃ )-X ¹ (19)

where m is an integer from 0 or more,

CF ₂ =CFOCF(CF ₃ )CF ₂ O(CF ₂ ) _n -X ¹ (20)

where n is an integer of 1 or more,

CF ₂ =CFOCF ₂ OCF ₂ CF(CF ₃ )OCF ₂ -X ¹ (21) and

=CH-(CF ₂ ) _n X ¹ (22)

where n is an integer from 2 to 8,

(in general formulas (5) - (22), X ¹ is as described above), and

they can be used alone or in any combination of two or more of them.

[0265] The iodine- or bromine-containing monomer represented by the general formula (4) is an iodine-containing fluorinated vinyl ether represented by the general formula (23):

where m is an integer from 1 to 5, and n is an integer from 0 to 3,

More specific examples include

and among them, ICF ₂ CF ₂ OCF=CF ₂ is preferred.

[0266] More specifically, the iodine- or bromine-containing monomer represented by the general formula (5) is preferably ICF ₂ CF ₂ CF= or I(CF ₂ CF ₂ ) ₂ CF=.

[0267] More specifically, the iodine- or bromine-containing monomer represented by the general formula (9) is preferably I(CF ₂ CF ₂ ) ₂ OCF=CF ₂ .

[0268] More specifically, the iodine- or bromine-containing monomer represented by the general formula (22) is preferably =CHCF ₂ CF ₂ I or I(CF ₂ CF ₂ ) ₂ CH=.

[0269] The monomer that provides the cross-linkable group is preferably a bisolefin compound represented by the formula: R ² R ³ C=CR ⁴ -Z-CR ⁵ =CR ⁶ R ⁷

where R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different and each represent H or an alkyl group containing from 1 to 5 carbon atoms; and Z represents a linear or branched alkylene or cycloalkylene group containing from 1 to 18 carbon atoms, which may contain an oxygen atom and which is at least partially fluorinated group or (per)fluoropolyoxyalkylene group. As used herein, "(per)fluoropolyoxyalkylene group" means a "fluoropolyoxyalkylene group or perfluoropolyoxyalkylene group".

[0270] Z represents a (per)fluoroalkylene group containing from 4 to 12 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ preferably represent hydrogen atoms.

[0271] Z, when it represents a (per)fluoropolyoxyalkylene group, is preferably a (per)fluoropolyoxyalkylene group represented by the formula:

-(Q) _p -CF ₂ O-(CF ₂ CF ₂ O) _m -(CF ₂ O) _n -CF ₂ -(Q) _p -

where Q is an alkylene group containing from 1 to 10 carbon atoms or an oxyalkylene group containing from 2 to 10 carbon atoms, p is 0 or 1, and m and n are integers, so that the ratio m/n is from 0.2 to 5, and the molecular weight of this (per)fluoropolyoxyalkylene group is in the range from 500 to 10000, and preferably from 1000 to 4000. In this formula, Q is preferably selected from -O- and -O(O) _s - (s =1-3).

[0272] A preferred bisolefin is

=CH-(CF ₂ ) ₂ -CH=,

=CH-(CF ₂ ) ₄ -CH=,

=CH-(CF ₂ ) ₆ -CH=,

formula: =CH-Z ¹ -CH=

where Z ¹ is -O-CF ₂ O-(CF ₂ CF ₂ O) _m -(CF ₂ O) _n -CF ₂ -O- (m/n is 0.5) and the molecular weight is preferably 2000, or anything like that.

[0273] Particularly preferred is 3,3,4,4,5,5,6,6,7,7,8,8-dodecafluoro-1,9-decadiene, represented by =CH-(CF ₂ ) ₆ - CH=.

[0274] The number average molecular weight Mn of the fluorine-containing elastomer is preferably 1,000 to 1,000,000, more preferably 10,000 to 500,000, and particularly preferably 20,000 to 300,000.

[0275] The fluorine content of the fluorine-containing elastomer is preferably 50% by weight or more, more preferably 55% by weight or more, even more preferably 60% by weight or more. The upper limit of fluorine content is preferably 75 mass% or less, and more preferably 73 mass% or less. The fluorine content is calculated based on the measured value obtained by ¹⁹ F-NMR, ¹ H-NMR, elemental analysis or the like.

[0276] The fluorine-containing elastomer preferably has a Mooney viscosity at 100°C (ML1+10 (100°C)) of 130 or less. More preferably, the Mooney viscosity is 110 or less, and even more preferably 90 or less. More preferably, the Mooney viscosity is 10 or more, and even more preferably 20 or more. In this document, Mooney viscosity is the value measured in accordance with JIS K 6300-1.2013.

[0277] The fluorine-containing elastomer preferably has a glass transition temperature of -50 to 0°C. More preferably, the glass transition temperature is -2°C or lower, and even more preferably -3°C or lower. More preferably, the glass transition temperature is -45°C or higher, and even more preferably -40°C or higher. The glass transition temperature may be -10°C or higher and may be -9°C or higher. Here, the glass transition temperature can be determined by heating 10 mg of sample at 20°C/min to obtain a DSC curve using a differential scanning calorimeter (for example, X-DSC 7000, manufactured by Hitachi High-Tech Science Corporation) and calculating the glass transition temperature from the differential DSC curve in accordance with JIS K 6240:2011.

[0278] The fluorine-containing elastomer preferably has an iodine content of 0.05 to 1.0 wt%, more preferably the iodine content is 0.08 wt% or more, and even more preferably 0.10 wt% or more, and more preferably 0.80 wt% or less, and even more preferably 0.60 wt% or less.

[0279] Iodine content can be determined using elemental analysis. In particular, iodine content can be measured by mixing 5 mg of Na ₂ SO ₃ with 12 mg of fluorine-containing elastomer, burning the mixture in oxygen in a quartz flask using an absorbent obtained by dissolving 30 mg of a 1:1 (mass ratio) mixture of Na ₂ CO ₃ and K ₂ CO ₃ in 20 ml of pure water, keeping the burnt mixture for 30 minutes, and then measuring the iodine content using a Shimadzu 20A ion chromatograph. A calibration curve can be generated using a KI standard solution containing 0.5 ppm. mass, and a standard KI solution containing 1.0 ppm. mass of iodine ions.

[0280] The fluorine-containing elastomer preferably contains an -I structure. The presence of structure -I can be verified by the ¹ H-NMR spectrum. A fluorine-containing elastomer containing the -I structure can be prepared by iodine transfer polymerization.

[0281] In the fluorine-containing elastomer, the amount of -CH ₂ I structure is preferably from 0.05 to 1.50 mol% relative to 100 mol% of -CH ₂ - structure. The amount of -CH ₂ I structure is more preferably 0.08 mol% or more, and even more preferably 0.12 mol% or more, and more preferably is 1.20 mol% or less, even more preferably 1.00 mol% or less, and particularly preferably 0.80 mol% or less. The amount of -CH ₂ I structure can be determined from the 1H-NMR spectrum.

[0282] More preferably, the fluorine-containing elastomer contains a -CF ₂ CH ₂ I structure. The fluorine-containing elastomer containing the -CF ₂ CH ₂ I structure can be obtained by preparing a VdF-based fluorine-elastomer by iodine transfer polymerization.

[0283] In the fluorine-containing elastomer, the amount of the -CF ₂ CH ₂ I structure is preferably from 0.05 to 1.50 mol% relative to 100 mol% of the -CH ₂ - structure. More preferably, the amount of -CF ₂ CH ₂ I structure is 0.08 mol% or more, and even more preferably 0.12 mol% or more, and more preferably is 1.20 mol% or less, even more preferably 1.00 mol% or less, and particularly preferably 0.80 mol% or less. The amount of structure -CF ₂ CH ₂ I is calculated as A/B∙100 from the integral value A of the intensities of all peaks observed in the chemical shift region from 3.75 to 4.05 ppm obtained for -CH ₂ I, and the integral B values of the intensities of all peaks observed at the chemical shift of the regions from 2.3 to 2.7 ppm. and from 2.9 to 3.75 ppm, derived from -CH ₂ - in the ¹ H-NMR spectrum.

[0284] A useful fluorine-containing monomer for use in the production method of the present invention may be a fluorine-containing monomer described with respect to a fluorine-containing elastomer.

[0285] Using the production method of the present invention, an aqueous dispersion of a fluorine-containing elastomer is obtained. The resulting aqueous fluorinated elastomer dispersion preferably contains a solids concentration (fluorinated elastomer content) of 10 to 50 wt%, more preferably 15 to 40 wt%, and even more preferably 20 to 30 wt% when polymerization is complete.

[0286] The solids concentration (fluorinated elastomer content) of the aqueous fluorinated elastomer dispersion can be determined by drying 1 g of the aqueous dispersion at 150°C for 180 minutes, measuring the mass of the heated residue, and calculating the ratio of the mass of the heated residue to the mass of the aqueous dispersion.

[0287] The aqueous dispersion of fluorine-containing elastomer may contain particles of fluorine-containing elastomer. The average particle size of the fluorine-containing elastomer is preferably from 10 to 800 nm, more preferably from 50 to 500 nm, and even more preferably from 70 to 300 nm. The average particle size of fluorine-containing elastomers is the cumulant average diameter and can be measured using dynamic light scattering.

[0288] The number of fluorine elastomer particles contained in the aqueous fluorine elastomer dispersion is preferably 1.0 x 10 ¹² particles/cm ³ or more, more preferably 5.0 x 10 ¹² particles/cm ³ or more, and even more preferably 1 .0 × 10 ¹³ particles/cm ³ or more. The number of particles (number of polymer particles) can be calculated according to the following expression:

[0289]

The number of particles of fluorine-containing elastomer obtained from the expression is equal to the number of particles per 1 cm ³ of water. The relative density is the relative density of the fluorine-containing elastomer. The relative density of the fluorine-containing elastomer can be determined in accordance with JIS Z 8807:2012.

[0290] Treatments, such as coagulation or heating, can be performed on the aqueous dispersion of the fluorine-containing elastomer.

[0291] Coagulation can be accomplished by adding an alkaline earth metal or earth metal salt to the aqueous dispersion. Examples of the alkaline earth or earth metal salt include sulfuric acid salt, nitric acid salt, hydrochloric acid salt and calcium magnesium aluminum acetic acid salt.

[0292] The coagulated fluoroelastomer can be washed with water to remove small amounts of impurities such as buffer and salt present in the fluoroelastomer, and then the washed fluoroelastomer can be dried. The drying temperature is preferably 40 to 200°C, more preferably 60 to 180°C, and even more preferably 80 to 150°C.

[0293] The form of the fluorine-containing elastomer obtained after coagulation is not limited, and may be a gum, crumb, powder, granule and the like, and is preferably a gum or crumb. Gum is a finely divided mass of fluorine-containing elastomer, and crumb is an amorphous mass of fluorine-containing elastomer formed by the fusion of particles that cannot maintain the shape of fine particles in the form of gum at room temperature. The gum or crumb is suitably obtained by coagulation, drying and the like, generally in a known manner, from the aqueous dispersion obtained by the production method of the present invention.

[0294] The polymer (1), degradation products and by-products of the polymer (1) obtained as a by-product from the polymer (1), residual monomers and the like can be collected from waste water generated by the above coagulation or washing, and /or from waste gases generated during drying and then purified for reuse of the polymer (1), from decomposition products and by-products of the polymer (1), obtained from the polymer (1), residual monomers and the like. Although the method for carrying out the above collection and purification is not limited, it can be carried out in a known manner. For example, this can be done in the manner described in the Japanese translation of PCT International Application Publication No. 2011-520020.

[0295] Although the method of collecting and purifying the polymer (1), degradation products and by-products of the polymer (1) generated as by-products from the polymer (1), residual monomers and the like from the generated wastewater as described above coagulation, waste water generated during washing, and waste gas generated during drying is not limited, a well-known method can be used. Examples thereof include the methods described in US Patent Application Publication No. 2007/0015937, US Patent Application Publication No. 2007/0025902 and US Patent Application Publication No. 2007/0027251, and specific examples thereof include the following methods.

[0296] Examples of a method for collecting the polymer (1), degradation products and by-products of the polymer (1) obtained during the production of the polymer (1), residual monomers and the like from the above waste water include a method in which the waste water is contacted with adsorbent particles composed of ion exchange resin, activated carbon, silica gel, clay, zeolite and the like, so that the polymer (1) and other substances are adsorbed on the adsorbent particles, and the waste water and the adsorbent particles are then separated. By burning the adsorbent particles that have adsorbed the polymer (1) and other substances, it is possible to prevent the polymer (1) and other substances from entering the environment.

[0297] Alternatively, the polymer (1) and other components can be collected by removing and eluting the polymer (1) and other components from the ion exchange resin particles that have adsorbed the polymer (1) and other components, in a known manner. For example, when the ion exchange resin particles are anion exchange resin particles, the polymer (1) and others can be eluted by contacting the mineral acid with the anion exchange resin. When a water-soluble organic solvent is then added to the resulting eluate, the mixture typically separates into two phases. Therefore, by collecting and neutralizing the lower phase containing polymer (1) and other substances, polymer (1) and other substances can be collected. Examples of the above water-soluble organic solvent include polar solvents such as alcohols, ketones and ethers.

[0298] Other examples of a method for collecting polymer (1) and other substances from ion exchange resin particles include a method using an ammonium salt and a water-soluble organic solvent, and a method using an alcohol and, if desired, an acid. In the latter method, ester derivatives of the polymer (1) and other substances are formed, and thus can be easily separated from the alcohol by distillation.

[0299] When the above waste water contains fluorine elastomer particles and other solids, it is preferable that they are removed before the waste water and the adsorbent particles come into contact with each other. Examples of the method for removing fluorine-elastomer particles and other solids include a method of adding aluminum salt or the like to precipitate these components and then separating waste water and sediment, and an electrocoagulation method. They can also be removed by mechanical means such as cross-flow filtration, deep filtration method or pre-filtration method.

[0300] The concentration of non-aggregated fluorine-containing elastomer in the waste water is preferably low, more preferably less than 0.4 wt% and especially preferably less than 0.3 wt% from a performance standpoint.

[0301] Examples of a method for collecting polymer (1) and other substances from exhaust gas include a method in which to contact the exhaust gas with deionized water, an alkaline aqueous solution, an organic solvent such as a glycol ether solvent or the like , a scrubber is used to produce a scrubbing solution containing polymer (1) and other substances. When a highly concentrated alkaline aqueous solution is used as the alkaline aqueous solution, the scrubbing solution can be collected in a state where the polymer (1) and other phases are separated, which makes it easier to collect and reuse the polymer (1) and other substances. Examples of the alkali metal compound include alkali metal hydroxides and quaternary ammonium salts.

[0302] The scrubbing solution containing the polymer (1) and other substances can be concentrated using a reverse osmosis membrane or the like. The concentrated scrubber solution usually contains fluoride ions. However, fluoride ions can be removed by further adding alumina after concentration to facilitate reuse of the polymer (1) and other substances. Alternatively, the adsorbent particles may be brought into contact with the scrubbing solution to adsorb the polymer (1) and other substances, thereby collecting the polymer (1) and other substances in the manner described above.

[0303] The polymer (1) and other substances collected by any of the above methods can be reused to produce a fluorine-containing elastomer.

[0304] The crosslinkable composition can be prepared by adding a cross-linking agent and the like to an aqueous dispersion of a fluorine-containing elastomer or a fluorine-containing elastomer obtained by the production method of the present invention. The type and amount of the cross-linking agent are not limited, and the cross-linking agent can be used within known limits.

[0305] When the fluorine-containing elastomer is a non-cross-linked elastomer, examples of the cross-linking system therefor include a peroxide cross-linking system, a polyol cross-linking system and a polyamine cross-linking system, and the cross-linking system is at least one system selected from the group consisting of a peroxide crosslinking system and a polyol crosslinking system. For chemical resistance, a peroxide crosslinking system is preferred, and for heat resistance, a polyol crosslinking system is preferred.

[0306] Accordingly, the cross-linking agent is at least one cross-linking agent selected from the group consisting of a polyol cross-linking agent and a peroxide cross-linking agent, and more preferably a peroxide cross-linking agent.

[0307] The amount of cross-linking agent contained is suitably selected according to the type of cross-linking agent and the like, and is from 0.2 to 6.0 parts by weight, and more preferably from 0.3 to 5.0 parts by weight relative to 100 parts by weight of fluorine-containing elastomer.

[0308] Peroxide cross-linking can be carried out using a non-cross-linked peroxide cross-linkable elastomer as the fluorine-containing elastomer and an organic peroxide as the cross-linking agent.

[0309] The peroxide cross-linkable non-cross-linked elastomer is not limited to, and may be a non-cross-linked elastomer having a peroxide cross-linkable portion. The active site capable of peroxide cross-linking is not limited, and examples thereof include an active site containing an iodine atom and an active site containing a bromine atom.

[0310] The organic peroxide may be an organic peroxide capable of readily forming peroxy radicals upon heating and in the presence of a redox system, and examples thereof include 1,1-bis(tert-butylperoxy)-3,5,5-trimethylcyclohexane, 2 ,5-dimethylhexane-2,5-dihydroperoxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di( tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexine-3, benzoyl peroxide, tert-butylperoxybenzene, tert-butylperoxymaleate, tert-butylperoxyisopropyl carbonate and tert-butylperoxybenzoate. Among them, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexine-3 are preferred.

[0311] The amount of organic peroxide contained is preferably from 0.1 to 15 parts by mass, and more preferably from 0.3 to 5 parts by mass, per 100 parts by mass of fluorine-containing elastomer.

[0312] When the cross-linking agent is an organic peroxide, the fluorine-containing elastomeric composition preferably further contains a cross-linking agent. Examples of the cross-linking additive include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N,N'-m-phenylene bismaleimide, dipropagyl terephthalate, diallyl phthalate, tetraallyl terephthalamide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate. (1,3,5-tris(2,3,3-trifluoro-2-propenyl)-1,3,5-triazine-2,4,6-trione), tris(diallylamine)-S-triazine, N, N-diallyl acrylamide, 1,6-divinyldecafluorohexane, hexaallylphosphoramide, N,N,N',N'-tetraallylphthalamide, N,N,N',N'-tetraallylmalonamide, trivinyl isocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri(5- norbornene-2-methylene)cyanurate, triallyl phosphite and trimetallyl isocyanurate. Among them, triallyl isocyanurate (TAIC) is preferred in terms of excellent cross-linkability, mechanical properties and flexibility.

[0313] The amount of cross-linking additive contained is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 7.0 parts by mass, and even more preferably 0.1 to 5.0 parts by mass per 100 parts by mass fluorine-containing elastomer. An amount of cross-linking additive less than 0.01 part by weight results in poor mechanical properties and poor flexibility. An amount exceeding 10 parts by mass tends to result in deterioration in heat resistance as well as poor durability of the molded product.

[0314] Cross-linking with polyols can be accomplished by using a non-crosslinkable elastomer capable of cross-linking with polyols as the fluorine-containing elastomer and a polyhydroxy compound as the cross-linking agent. In the polyol cross-linking system, the amount of the polyhydroxy compound contained is preferably from 0.01 to 10 parts by weight per 100 parts by weight of the non-crosslinkable polyol crosslinkable elastomer. When the amount of the polyhydroxy compound contained is in such a range, cross-linking with the polyol can be accelerated sufficiently. More preferably, the amount is from 0.02 to 8 parts by mass. Even more preferably, the amount is from 0.03 to 4 parts by mass.

[0315] The non-cross-linked elastomer capable of being cross-linked by a polyol is not limited to, and may be a non-cross-linked elastomer having a portion capable of being cross-linked by a polyol. The active site capable of cross-linking with the polyol is not limited, and may be, for example, an active site containing a vinylidene fluoride (VdF) unit. The method of introducing a cross-linking active site may be a method including copolymerizing a monomer that provides a cross-linking active site during polymerization of the non-crosslinked elastomer.

[0316] A useful polyhydroxy compound may be an aromatic polyhydroxy compound in terms of excellent heat resistance.

[0317] The aromatic polyhydroxy compound is not limited, and examples thereof include 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A), 2,2-bis(4-hydroxyphenyl)perfluoropropane (hereinafter referred to as bisphenol AF, and bisphenol AF is available, for example, from FUJIFILM Wako Pure Chemical Corporation or Central Glass Co., Ltd.), 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, dihydroxynaphthalene, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis(4-hydroxyphenyl)butane (hereinafter referred to as bisphenol B), 4,4-bis(4 -hydroxyphenyl)valeric acid, 2,2-bis(4-hydroxyphenyl)tetrafluorodichloropropane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylketone, tri(4-hydroxyphenyl)methane, 3,3',5,5'- tetrachlorobisphenol A and 3,3',5,5'-tetrabromobisphenol A. These aromatic polyhydroxy compounds may be alkali metal salts, alkaline earth metal salts and the like, and when the copolymer is coagulated with an acid, metal salts are preferably not used. The amount of the aromatic polyhydroxy compound contained is from 0.1 to 15 parts by mass, and preferably from 0.5 to 5 parts by mass, per 100 parts by mass of non-crosslinked elastomer.

[0318] When the cross-linking agent is a polyhydroxy compound, the fluorine-containing elastomeric composition preferably further contains a cross-linking accelerator. The cross-linking accelerator promotes the formation of an intramolecular double bond in the reaction of dehydrofluorination of the polymer backbone and the addition of a polyhydroxy compound to the resulting double bond.

[0319] The cross-linking accelerator can be used in combination with an acid scavenger such as magnesium oxide or a cross-linking additive.

[0320] Examples of the cross-linking accelerator include onium compounds, and among the onium compounds, the cross-linking accelerator is preferably at least one accelerator selected from the group consisting of ammonium compounds such as quaternary ammonium salt, phosphonium compounds such such as a quaternary phosphonium salt, oxonium compounds, sulfonium compounds, cyclic amines and monofunctional amine compounds, and more preferably at least one accelerator selected from the group consisting of quaternary ammonium salts and quaternary phosphonium salts.

[0321] The quaternary ammonium salt is not limited, and examples thereof include 8-methyl-1,8-diazabicyclo[5,4,0]-7-undecium chloride, 8-methyl-1,8-diazabicyclo[5,4,0 ]-7-undecium iodide, 8-methyl-1,8-diazabicyclo[5,4,0]-7-undecene hydroxide, 8-methyl-1,8-diazabicyclo[5,4,0]-7-undecinium methyl sulfate , 8-ethyl-1,8-diazabicyclo[5,4,0]-7-undecenium bromide, 8-propyl-1,8-diazabicyclo[5,4,0]-7-undecenium bromide, 8-dodecyl-1 ,8-diazabicyclo[5,4,0]-7-undecinium chloride, 8-dodecyl-1,8-diazabicyclo[5,4,0]-7-undecinium hydroxide, 8-eicosyl-1,8-diazabicyclo[5 ,4,0]-7-undecinium chloride, 8-tetracosyl-1,8-diazabicyclo[5,4,0]-7-undecinium chloride, 8-benzyl-1,8-diazabicyclo[5,4,0]- 7-Undecenium Chloride (hereinafter referred to as DBU-B, and DBU-B is available, for example, from FUJIFILM Wako Pure Chemical Corporation), 8-benzyl-1,8-diazabicyclo[5,4,0]-7-undecinium hydroxide , 8-phenethyl-1,8-diazabicyclo[5,4,0]-7-undecenium chloride, 8-(3-phenylpropyl)-1,8-diazabicyclo[5,4,0]-7-undecenium chloride, tetrabutylammonium hydrogen sulfate, tetrabutylammonium hydroxide, tetrabutylammonium chloride and tetrabutylammonium bromide. Among them, DBU-B is preferred in terms of crosslinkability, mechanical properties and flexibility.

[0322] The quaternary phosphonium salt is not limited, and examples thereof include tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltrimethylphosphonium chloride, benzyltributylphosphonium chloride, tributylphosphonium chloride, tributyl-2-methoxypropylphosphonium chloride and benzylphenyl(dimethylamino)phosphonium chloride, and among Of these, benzyltriphenylphosphonium chloride (BTPPC) is preferred in terms of cross-linkability, mechanical properties and flexibility.

[0323] The cross-linking accelerator may be a quaternary ammonium salt-bisphenol AF solid solution, a quaternary phosphonium salt-bisphenol AF solid solution, or a chlorine-free cross-linking accelerator described in Japanese Patent Laid-Open No. 11-147891.

[0324] The amount of cross-linking accelerator contained is preferably 0.01 to 8.00 parts by mass, and more preferably 0.02 to 5.00 parts by mass, based on 100 parts by mass of uncrosslinked elastomer. Even more preferably, the amount is from about 0.03 to 3.00 parts by mass. When the amount of the cross-linking accelerator is less than 0.01 part by mass, there is a possibility that the cross-linking of the non-cross-linked elastomer will be insufficient, and the resulting molded product will have poor heat resistance and the like. When the amount exceeds 8.00 parts by weight, there is a possibility that the fluorine-containing elastomer composition will have poor moldability, and there is a tendency for elongation to decrease in relation to mechanical properties as well as flexibility to decrease.

[0325] An acid scavenger is used to neutralize the acidic substance formed during polyol cross-linking, and specific examples include magnesium oxide, calcium hydroxide (for example, NICC 5000 (manufactured by Inoue Calcium Corporation), CALDIC #2000, CALDIC #1000 (manufactured by Ohmi Chemical Industry Co., Ltd.)), calcium oxide, litharge (lead oxide), zinc oxide, dibasic lead phosphite and hydrotalcite, and the acid scavenger is at least one scavenger selected from the group consisting of high reactive magnesium oxide and low reactive magnesium.

[0326] Cross-linking of polyamines can be carried out using a fluorine-containing elastomer capable of cross-linking with polyamines as the fluorine-containing elastomer and a polyamine compound as the cross-linking agent.

[0327] The fluorine-containing elastomer capable of cross-linking with polyamines is not limited to, and may be a fluorine-containing elastomer having an active site capable of cross-linking with polyamines. The active site capable of cross-linking with polyamines is not limited, and may be, for example, an active site containing a vinylidene fluoride (VdF) unit. The method of introducing a cross-linking active site may be a method including copolymerizing a monomer that provides a cross-linking active site during polymerization of a fluorine-containing elastomer.

[0328] Examples of the polyamine compound include hexamethylenediamine carbamate, N,N'-dicinnamylidene-1,6-hexamethylenediamine, and 4,4'-bis(aminocyclohexyl)methane carbamate. Among them, N,N'-dicinnamylidene-1,6-hexamethylenediamine is preferred.

[0329] The method for producing the cross-linkable composition is not limited as long as the method allows the fluorine-containing elastomer obtained by the production method of the present invention to be uniformly mixed with the cross-linking agent. An example may be a method involving mixing the powder obtained by coagulating only the fluorine-containing elastomer, and, if necessary, another additive or compounding agent using a mixer, for example, with open shafts.

[0330] The present description also relates to a composition containing a fluorine-containing elastomer and a polymer (1) containing a polymerization unit (1) based on a monomer (1) represented by the general formula (1):

CF ₂ =CF-R-CZ ¹ Z ² -COOM (1)

where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group.

[0331] A usable configuration of the fluorine-containing elastomer is the same as the configuration of the fluorine-containing elastomer produced by the production method of the present invention.

[0332] The usable configuration of the polymer (1) is the same as the configuration of the polymer (1) used in the production method of the present invention.

[0333] The form of the composition of the present invention is not limited, but may be, for example, an aqueous dispersion, gum, crumb, powder, granules or the like. Aqueous dispersion refers to a dispersion system in which the aqueous medium is the dispersion medium and the fluorine-containing elastomer is the dispersed phase. The aqueous medium is not limited to, as long as it is a liquid containing water, and may contain, in addition to water, an organic solvent such as an alcohol, ether, ketone or paraffin wax.

[0334] The lower limit value of the polymer (1) in the composition is preferably about 0.00001 wt%, more preferably 0.0001 wt%, even more preferably 0.001 wt%, and especially preferably 0.01 wt% based on the fluorine elastomer . The upper limit value of the polymer (1) in the composition is preferably 20 mass%, more preferably 10 mass%, even more preferably 6 mass%, more preferably 4 mass%, and most preferably 2 mass% or less.

[0335] The content of polymer (1) in the composition can be determined, for example, by solid-state ¹⁹ F-MAS NMR measurement. Examples of the polymer content measurement method (1) include polymer content measurement methods suitably described in International Publication No. WO 2014/099453, International Publication No. WO 2010/075497, International Publication No. WO 2010/075496, International Publication No. WO 2011/008381, International Publication No. WO 2009/055521, International Publication No. WO 1987/007619, Japanese Patent Laid-Open No. 61-293476, International Publication No. WO 2010/075494, International Publication No. WO 2010/075359, International Publication No. WO 2006/119224, International Publication No. WO 2013/085864, International Publication No. WO 2012/082707, International Publication No. WO 2012/082703, International Publication No. WO 2012/082454, International Publication No. WO 2012/082451, International Publication No. WO 2006/135825, International Publication No. No. WO 2004/067588, International Publication No. WO 2009/068528, in Japanese Patent Laid-Open No. 2004-075978, Japanese Patent Laid-Open No. 2001-226436, in International Publication No. WO 1992/017635, International Publication No. WO 2014/069165, in Laid-Open Japanese Patent No. 11-181009, and the like. Specific examples of devices used for this purpose include the AVANCE III HD400 from Bruker and the AVANCE300 from Bruker. The rotation speed is set in accordance with the resonant frequency of the device for and is set such that the sideband from the rotation does not overlap the peaks used to calculate the content of fluorine-containing elastomer or polymer (1).

[0336] The content of polymer (1) in the composition can also be measured in the following way. It can be measured by a method in which the composition is mixed with a solvent that dissolves the fluorine-containing elastomer, the resulting mixed solution is added dropwise to deionized water to extract the polymer (1) from the resulting mixed solution, the aqueous phase containing the polymer (1) is collected and the mass is measured residue (polymer (1)) obtained by heating and drying the collected aqueous phase to calculate the content of polymer (1).

[0337] Examples of the solvent that dissolves the fluorine-containing elastomer include a ketone solvent, an ether solvent, a perfluorobenzene ester solvent, and the ketone solvent is preferably acetone, the ether solvent is preferably tetrahydrofuran and the ester solvent is preferably ethyl acetate.

[0338] The composition of the present invention may be an aqueous dispersion containing a fluorine-containing elastomer, a polymer (1) and an aqueous medium. The upper limit of the solids concentration in the aqueous dispersion is preferably 50% by weight, more preferably 40% by weight, even more preferably 35% by weight and especially preferably 30% by weight with respect to the aqueous dispersion. The lower limit of solids concentration in the aqueous dispersion is preferably 5 wt%, more preferably 10 wt%, even more preferably 15 wt%, and particularly preferably 20 wt%. The solid concentration in the aqueous dispersion can be controlled by diluting or concentrating the aqueous dispersion obtained by polymerization.

[0339] The aqueous dispersion solids concentration refers to the concentration of solids contained in the aqueous dispersion. Examples of solids include fluorine-containing elastomer and polymer (1). The concentration of solids in the aqueous dispersion may also represent the total content of fluorine-containing elastomer and polymer (1) in the aqueous dispersion. The solid concentration of the aqueous dispersion can be determined by drying 1 g of the aqueous dispersion at 150° C. for 180 minutes, measuring the mass of the heated residue, and calculating the ratio of the mass of the heated residue to the mass of the aqueous dispersion.

[0340] The composition of the present invention preferably contains substantially no fluorosurfactant.

[0341] The expression "substantially free of fluorosurfactant" as used herein means that the fluorosurfactant content is 10 ppm. mass or less in terms of fluorine-containing elastomer. The fluorine surfactant content is preferably 1 ppm. mass or less, more preferably 100 ppb mass or less, even more preferably 10 ppb mass or less, even more preferably 1 ppb mass or less, and especially preferably the fluorinated surfactant content is below the detection limit measured using liquid chromatography-mass spectrometry (LC/MS).

[0342] The fluorine surfactant content can be quantified in a known manner, and can be quantified, for example, by LC/MS analysis.

[0343] First, an organic solvent such as methanol is added to the resulting aqueous dispersion, powder, granules, molded article or dust obtained by micronizing the granules, molded article or molded article to extract the fluorosurfactant, and the extracted liquid is subjected to analysis LC/MS. Molecular mass information is extracted from the acquired LC/MS spectrum to confirm the structural formula of the surfactant candidate. The extraction method may be a Soxhlet extraction method.

[0344] Aqueous solutions having five or more different concentration levels of the confirmed surfactant are then prepared and aqueous solutions at the corresponding concentration levels are analyzed by LC/MS to obtain a calibration curve of peak area versus concentration.

[0345] That is, the fluorine surfactant content can be measured, for example, by adding methanol to the composition to perform extraction and subjecting the resulting extracted liquid to LC/MS analysis.

To further improve the extraction efficiency, treatment can be carried out using Soxhlet extraction, ultrasonication or the like.

From the resulting LC/MS spectrum, molecular weight information is extracted to confirm that the candidate fluorine surfactant matches the structural formula.

Aqueous solutions having five or more different levels of the identified fluorosurfactant are then prepared and the aqueous solutions at the corresponding levels are analyzed by LC/MS and a calibration curve is constructed for the relationship between the content and the area corresponding to the content.

Using the calibration curve, the area of the LC/MS chromatogram of fluorosurfactant in the extracted liquid can then be converted to fluorosurfactant content.

[0346] The fluorine surfactant is the same as those given above as an example with reference to the production method of the present invention. For example, a fluorine surfactant may be a surfactant containing a fluorine atom having, excluding an anionic group, only 20 or less carbon atoms, it may be a fluorine surfactant containing an anionic moiety having a molecular weight 800 or less and may be a fluorosurfactant having a LogPOW of 3.5 or less.

[0347] Examples of the anionic fluorosurfactant include the compound represented by the general formula (N ⁰ ), and specific examples thereof include the compound represented by the general formula (N ¹ ), the compound represented by the general formula (N ² ), the compound represented by the general formula (N ² ), a compound represented by the general formula (N ³ ), a compound represented by the general formula (N ⁴ ), and a compound represented by the general formula (N ⁵ ). More specific examples include perfluorocarboxylic acid (I) represented by the general formula (I), ω-H perfluorocarboxylic acid (II) represented by the general formula (II), perfluoroethercarboxylic acid (III) represented by the general formula (III), perfluoroalkylalkylenecarboxylic acid (IV ) represented by the general formula (IV), perfluoroalkoxyfluorocarboxylic acid (V) represented by the general formula (V), perfluoroalkylsulfonic acid (VI) represented by the general formula (VI), ω-H perfluorosulfonic acid (VII) represented by the general formula (VII) , perfluoroalkylene sulfonic acid (VIII) represented by the general formula (VIII), alkylalkylene carboxylic acid (IX) represented by the general formula (IX), fluorocarboxylic acid (X) represented by the general formula (X), alkoxyfluorosulfonic acid (XI) represented by the general formula ( XI), the compound (XII) represented by the general formula (XII), and the compound (XIII) represented by the general formula (XIII).

[0348] The composition of the present invention can be suitably produced using the production method of the present invention.

[0349] The present invention also relates to a cross-linkable composition containing the above composition and a cross-linking agent. A useful configuration of the cross-linking agent is the same as that of the cross-linking composition obtained by the production method of the present invention.

[0350] The cross-linkable composition may contain at least one multifunctional compound. A polyfunctional compound is a compound containing two or more functional groups, having the same or different structure, in one molecule. The functional group contained in the multifunctional compound may be a functional group that is generally chemically active, such as a carbonyl group, a carboxyl group, a haloformyl group, an amide group, an olefin group, an amino group, an isocyanate group, a hydroxyl group, or an epoxy group. group.

[0351] The cross-linkable composition may contain a conventional additive that is added to the elastomer as needed, such as a filler (such as carbon black or barium sulfate), a processing aid (such as a wax), a plasticizer, a colorant, a stabilizer, an adhesion agent ( such as coumarone resin or coumarone indene resin), mold release agent, electrical conductivity agent, thermal conductivity agent, anti-stick agent, flexibility agent, heat resistance improving agent, flame retardant and the like various additives and may contain, at least one conventional cross-linking agent other than those described above, or a cross-linking accelerator.

[0352] The content of filler such as carbon black is not limited, and is preferably 0 to 300 parts by mass, more preferably 1 to 150 parts by mass, even more preferably 2 to 100 parts by mass, and particularly preferably 2 to 75 parts by mass parts per 100 parts by weight of fluorine-containing elastomer.

[0353] The content of the processing aid such as wax is preferably 0 to 10 parts by mass, and more preferably 0 to 5 parts by mass, per 100 parts by mass of fluorine-containing elastomer. When processing aid, plasticizer and mold release agent are used, the mechanical properties and sealing ability of the resulting molded article tend to deteriorate, and thus their content must be adjusted so that the characteristics of the resulting molded article are acceptable.

[0354] By cross-linking the cross-linkable composition, a molded article can be obtained. In addition, by molding and cross-linking the cross-linkable composition, a molded product can be obtained. The crosslinkable composition can be prepared in a generally known manner. The molding and cross-linking methods and conditions are within the scope of known methods and conditions for conventional molding and cross-linking. The order of molding and cross-linking is not limited, and the composition may be formed and then cross-linked, may be cross-linked and then molded, or may be molded and then cross-linked at the same time.

[0355] Examples of the molding method include, but are not limited to, compression molding, casting, injection molding, extrusion, and Rotocure molding. As for the cross-linking method, steam cross-linking, heating cross-linking, radiation cross-linking and other methods can be used, among which steam cross-linking and heating cross-linking are preferred. Non-limiting specific crosslinking conditions may be determined as necessary according to the types of crosslinking accelerator, crosslinking agent, acid scavenger and other parameters, generally within a temperature range of 140 to 250° C. and crosslinking time of 1 minute to 24 hours.

[0356] By heating the resulting molded article in an oven or the like, the mechanical properties and high-temperature compression set characteristics can be improved. Non-limiting specific cross-linking conditions may be determined as necessary according to the types of cross-linking accelerator, cross-linking agent, acid scavenger and others, generally within a temperature range of 140 to 300° C. and a time range of 30 minutes to 72 hours.

[0357] The molded article has excellent properties such as heat resistance, oil resistance, chemical resistance and flexibility, as well as excellent high temperature compression set properties. Thus, molded products are typically used for areas that slide in contact with other materials, encapsulate or seal other materials or substances, or are intended for vibration protection or sound insulation, and can be used as various components in various applications, such as such as the automobile industry, aircraft manufacturing and semiconductor industry.

[0358] Examples of areas in which the molded article is used include: the semiconductor area; automotive sector; aviation field; astronautics and rocket science; delivery area; chemical products area such as chemical plants; pharmaceutical field, such as drug production; photography area such as developers; printing area such as printing machines; painting area such as painting equipment; the field of analytical and physical-chemical equipment, such as the field of analytical equipment and measuring equipment; the field of food equipment, including equipment for food factories and household goods; equipment for the production of beverages and food; area of equipment for pharmaceutical production; production of medical components; the field of equipment for the transportation of chemical reagents; areas of equipment for nuclear power plants; iron and steel production, such as sheet metal processing plants; general industrial sphere; field of electrical engineering; fuel cell field; area of electronic components; area of optical equipment components; area of space equipment components; field of petrochemical equipment; the field of equipment components for exploration and production of energy resources such as oil and gas; the field of oil refining and the field of equipment components for oil transportation.

[0359] Examples of molded product uses include various sealing materials and packings such as rings, packings, gaskets, diaphragms, oil seals, bearing seals, lip seals, plunger seals, door seals, lip and end seals, gas supply devices, plate seals , plate support seals and barrel seals. The molded product can be used as a sealing material in applications requiring heat resistance, solvent resistance, chemical resistance and non-tackiness.

[0360] The molded article can also be used as a tube, hose, roller, various types of rubber rolls, flexible joint, rubber plate, cover, belt, damper, valve, valve seat, valve body, chemical resistant cover material, lamination material, lining material and the like.

[0361] The cross-section of the ring, packing, and seal may have any of various shapes. In particular, it may have, for example, a square shape, an O-shape or a tip, or it may have an irregular shape such as a D-shape, L-shape, T-shape, V-shape, X-shape or Y-shape. figurative form.

[0362] In the field of semiconductors, the molded article can be used, for example, for semiconductor manufacturing devices, liquid crystal panel manufacturing devices, plasma panel manufacturing devices, plasma display panel manufacturing devices, plasma addressable liquid crystal panel manufacturing devices , devices for the production of organic electroluminescent panels, devices for the production of field emission display panels, devices for the production of solar cell substrates, semiconductor transport devices and the like. Examples of such devices include: CVD devices; gas control devices such as gas control devices for semiconductors; dry etching devices; wet etching devices; devices for plasma etching; devices for reactive ion etching; devices for reactive ion beam etching; spray etching devices; devices for ion beam etching; oxidation-diffusion devices for; spray devices for; ashing devices; devices for plasma ashing; cleaning devices for; ion implantation devices; plasma CVD devices for; ventilation devices for; exposure devices for; polishing devices for; film-forming devices for; dry etching cleaning devices; UV/O ₃ cleaning devices; devices for ion-beam cleaning; laser beam cleaning devices; plasma cleaning devices; gas etching cleaning devices; extraction cleaning devices; devices for extraction purification using a Soxhlet apparatus; high temperature extraction devices for high pressure cleaning; devices for purification using microwave extraction; devices for supercritical extraction purification; devices for cleaning with hydrofluoric acid, hydrochloric acid, sulfuric acid, ozone water and the like; steppers; varnishers/developers; devices for CMP; excimer laser exposure machines; pipelines for chemical solutions; gas pipelines; devices on which plasma treatment is performed, such as NF ₃ plasma treatment, O ₂ plasma treatment and fluoride plasma treatment; devices for heat treatment with film formation; equipment for transporting plates; plate cleaning devices; devices for cleaning silicon wafers; devices for processing silicon wafers; devices used in the LP-CVD process; devices for lamp annealing and devices used in the reflow process.

[0363] Specific examples of use in the semiconductor related field include: various sealing materials such as O-rings and gaskets for check valves, quartz windows, chambers, chamber covers, gates, caps, couplings and pumps; various sealing materials such as O-rings, hoses and tubing for resist development and removal solutions; linings and coatings for resist development baths, resist removal baths, wafer cleaning baths and wet etching baths; diaphragms for pumps; rollers for transporting plates; hoses for cleaning solutions for plates; sealing materials for cleanrooms, such as sealants for cleanrooms, including the cleanrooms themselves; sealing materials for warehouses for storing apparatus and devices for the production of semiconductors, for example, wafers; and diaphragms for carrying chemical solutions used in the semiconductor manufacturing process.

[0364] In the automotive field, the molded product can be used for engine housing, main engine system, valve train system, lubrication/cooling system, fuel system, intake/exhaust system, passenger car transmission system, drive system, chassis steering system, brake system and electrical components such as main electrical components, electrical control system components and electrical equipment components. The automotive field also includes motorcycles.

[0365] In the engine casing and its peripheral devices described above, the molded product can be used for various sealing materials, which must have heat resistance, oil resistance, fuel oil resistance, engine cooling antifreeze resistance and steam resistance, and examples of such sealing materials materials also include seals such as gaskets, shaft seals and valve stem seals, non-contact or contact type seals such as self-sealing seals, piston rings, split ring seals, mechanical seals and oil seals, bellows, diaphragms, hoses, tubes and various sealing materials used for electrical wires, gasket materials, vibration-proofing materials and belt devices for vehicles.

[0366] Specific examples of use in the fuel system include: O-rings used for fuel injectors, cold start injectors, fuel line quick connects, sensor flange quick connects, fuel pumps, fuel tank quick connects, gasoline mix pumps, gasoline pumps, fuel line housings , fuel pipe connectors, injectors and the like; seals for intake manifolds, fuel filters, pressure control valves, canisters, fuel caps, fuel pumps, fuel tanks, fuel tank sensors, fuel injection devices, high pressure fuel pumps, fuel line connector systems, pump timing control valves, suction control valves, solenoid units, fuel shut-off valves, etc.; canister purge solenoid valve seals, onboard vapor recovery (ORVR) valve seals, fuel pump seals, fuel level sensor seals, fuel tank tilt valve seals, filler neck seals, injector seals, filler cap seals, and fuel filler cap valve seals; hoses such as fuel hoses, fuel supply hoses, fuel return hoses, steam (evaporation) hoses, vent (breather) hoses, fill hoses, filler hoses, hoses in fuel tanks (in-tank hoses), carburetor control hoses, fuel inlet hoses and hoses fuel breather; gaskets used for fuel filters, fuel line connector systems and the like, and flange gaskets used for carburetors and the like; piping materials such as vapor recovery lines, fuel lines, and steam/ORVR lines; diaphragms for canisters, ORVR, fuel pumps, pressure sensors in fuel tanks, gasoline pumps, carburetor sensors, combined air distributors (CAC), pulsation dampers, canisters, truck cranes and the like, as well as diaphragms for pressure regulators of fuel devices; fuel pump valves, carburetor needle valves, check valves and pressure valves; tubes used in vents (breathers) and fuel tanks; seals of fuel tanks and the like, as well as seals of pistons of accelerator pumps of carburetors; vibration isolation components for fuel tanks; O-rings and diaphragms for fuel pressure control; accelerator pump cups; mounting the fuel pump in the tank; rings of injector cushions of fuel injection devices; injector O-rings; carburetor needle valve cores; carburetor accelerator pump pistons; valve seats of combined pneumatic control devices; fuel tank housings; and sealing components for solenoid valves.

[0367] Specific examples of use in the brake system include diaphragms used for brake booster master cylinder assemblies, air brake hydraulic brake hoses, air brake brake chambers, and the like; hoses used for brake hoses, brake oil hoses, vacuum brake hoses and the like; various sealing materials such as oil seals, O-rings, packings and brake piston seals; atmospheric valves and vacuum valves for master cylinders with vacuum booster assemblies and check valves for brake valves; piston seals (rubber seals) for master cylinders and brake cups; O-rings and bushings of the master cylinders and vacuum boosters of hydraulic brakes, boots of the working cylinders of hydraulic brakes and anti-lock brake system (ABS).

[0368] Specific examples of use in basic electrical components include electrical wire insulators and jackets (harnesses), external harness component tubing, and connector bushings.

[0369] Specific examples of use in electrical components of a control system include coating materials for various sensor wires.

[0370] Specific examples of use in electrical equipment components include automotive air conditioning O-rings and seals, coolant hoses, high pressure air conditioning hoses, air conditioning hoses, gaskets for electronic throttle bodies, direct ignition plug bushings, and diaphragms for distribution elements. The molded product can also be used to connect electrical components.

[0371] Specific examples of use in the air intake and exhaust system include: seals used for intake manifolds, exhaust manifolds and the like, and throttle body seals; diaphragms used for EGR (exhaust gas recirculation), boost control (BPT), wastegate valves, turbo wastegate valves, actuators, variable geometry turbine (VTG) drives, exhaust gas aftertreatment valves and the like; hoses such as EGR (exhaust gas recirculation) control hoses, emission control hoses, turbo oil hoses (supply) and turbo oil hoses (return) of turbochargers, turbo air hoses, intercooler hoses, turbocharger hoses, hoses connected to compressors of turbo engines equipped with intercoolers , exhaust gas hoses, air intake hoses, turbo hoses and DPF (diesel particulate filter) sensor hoses; air ducts and turbo air ducts; intake manifold gaskets; and materials of EGR seals, valve seats, AB valves to prevent burnout, turbine shaft seals (turbochargers and the like) and sealing elements used for rocker covers used in automobile engines and for air intake manifold groove components and the like

[0372] In addition, in the exhaust gas control component, the molded article can be used as any of the seals used for vapor recovery canisters, catalytic converters, exhaust gas sensors, oxygen sensors and the like, and seals for vapor recovery solenoid valves and vapor canisters ; intake manifold gaskets; etc.

[0373] Additionally, in a diesel engine component, the molding may be used as any of O-rings for direct injectors, rotary pump seals, control diaphragms, fuel hoses, EGR, boost pumps, boost compensator diaphragms, and the like. similar. The molded product can also be used for O-rings, sealing materials, hoses, pipes, diaphragms, gasket materials and pipes used for SCR urea systems, urea water tank bodies of SCR urea systems, sealing materials for urea water tanks and like.

[0374] Specific examples of use in a transmission system include transmission-related bearing seals, oil seals, O-rings, seals, and torque converter hoses. Examples also include transmission seals and transmission oil hoses, ATF hoses, O-rings, and AT seals.

[0375] It should be noted that transmissions include AT (automatic transmission), MT (manual transmission), CVT (continuously variable transmission), DCT (dual clutch transmission) and the like.

[0376] Examples also include seals, gaskets, O-rings and packings for manual or automatic transmissions, seals, gaskets, O-rings and packings for continuously variable transmissions (belt or toroidal type), seals for ATF linear solenoids, oil hoses for manual transmissions gears, ATF hoses for automatic transmissions and CVTF hoses for continuously variable transmissions (belt or toroidal type).

[0377] Specific examples of use in the steering system include power steering oil hoses and high pressure power steering hoses.

[0378] Examples of use in automotive engine housings include gaskets such as cylinder head gaskets, cylinder head gaskets, oil pan seals and general purpose gaskets, seals such as O-rings, timing belt cover seals and gaskets, hoses such as hoses controls, vibration-proof rubber engine mounts, control valve diaphragms and camshaft seals.

[0379] In the main drive system of an automobile engine, the molded article can be used for shaft seals such as crankshaft seals and camshaft seals and the like.

[0380] In an automotive engine valve train system, the molded product may be used for engine valve stem seals, throttle valve seats, and the like.

[0381] In an automobile engine lubrication and cooling system, the molded product can be used for engine oil cooler hoses, oil return hoses, sealing gaskets, water hoses around radiators, radiator seals, radiator gaskets, radiator O-rings, vacuum pump oil hoses and vacuum pumps, and also radiator hoses, radiator tanks, oil pressure diaphragms, fan clutch seals and the like.

[0382] As described above, specific examples of use in the automotive field include engine head gaskets, oil pan gaskets, manifold seals, oxygen sensor seals, oxygen sensor bushings, nitrogen oxide ( _NOx ) sensor seals, nitrogen oxide (NO) sensor bushings _x ), sulfur oxide sensor seals, temperature sensor seals, temperature sensor bushings, particulate filter sensor seals, particulate filter sensor bushings, injector o-rings, injector seals, fuel pump o-rings and diaphragms, transmission seals, power piston seals, liner seals cylinders, valve stem seals, static valve stem seals, dynamic valve stem seals, automatic transmission front pump valve seals, rear axle gear seals, universal joint gaskets, speedometer gear seals, foot brake piston cups, O-rings and oil seals for torque transfer devices, oil seals and bearing seals for exhaust gas afterburning devices, hoses for afterburning devices, carburetor sensor diaphragms, rubber vibration insulation (engine mounts, exhaust units, suspension muffler, suspension bushings, central bearings, rubber strut shock absorbers, etc.), rubber vibration insulation for suspensions (mounts, bushings and the like), rubber vibration isolation of drive systems (dampers and the like), fuel hoses, EGR pipes and hoses, carburetor twin pipes, carburetor needle valve cores, carburetor gasket flanges, oil hoses, oil cooler hoses, ATF hoses, head gaskets cylinders, water pump seals, transmission seals, needle valve tips, motorcycle reed reeds, automotive engine seals, gas hose gun seals, automotive air conditioner seals, rubber hoses for engine intercoolers, fuel line connection system seals, CAC valves, needle tips, electrical wires around engines, filler hoses, auto A/C O-rings, intake gaskets, fuel tank materials, distributor diaphragms, water hoses, clutch hoses, PS hoses, AT hoses, brake master cylinder hoses with vacuum booster assemblies, heater hoses, A/C hoses , ventilation hoses, oil filler caps, PS rack seals, rack and pinion boots, CVJ boots, ball joint boots, strut boots, sealing strips, double glazed windows, center block seals, body side gaskets, bumper rubbers, door locks, instrument panel insulators, cables high voltage, flat belts, poly V-belts, timing belts, V-belts, tires, windshield wiper blades, diaphragms and plungers for regulators of gas vehicles, diaphragms and valves for regulators of gas vehicles, rubber parts resistant to DME, diaphragms and boots for auto tensioners, diaphragms and idle speed control valves, automatic speed control actuators, diaphragms, check valves and vacuum pump plungers, OPS diaphragms and O-rings, gasoline pressure relief valves, engine cylinder liner O-rings and gaskets, wet cylinder liner O-rings and gaskets, seals and differential gaskets (seals and gaskets for transmission oils), oil seals and gaskets for power steering devices (seals and gaskets for PSF), seals and gaskets for shock absorbers (seals and gaskets for SAF), seals and gaskets for constant speed joints, wheel bearing seals and gaskets, coating agents for metal gaskets, caliper seals, boots, wheel bearing seals and tubes used for vulcanization molding of tires.

[0383] In the aviation, space, missile, and shipping fields, the molded product can be used, in particular, for fuel systems and lubricating oil systems.

[0384] In the field of aircraft applications, the molded article may be used, for example, as any of various aircraft seal components, various aircraft components in aircraft engine oils, jet engine valve stem seals, gaskets and O-rings, rotary shaft seals, gaskets hydraulic equipment, fire seals, hoses, gaskets and O-rings for fuel supply, cables, oil seals and shaft seals for aircraft and the like.

[0385] In the space and missile field, the molded article can be used, for example, as any lip seals, diaphragms and O-rings of space vehicles, jet engines, rockets and the like, oil-resistant gas turbine engines, O-rings and vibration-isolating pads for level control of rockets land.

[0386] Also, in the marine field, the molded article can be used, for example, as any of the stern seals of propeller shafts, valve stem seals for the intake and exhaust of diesel engines, butterfly valve seals, valve seats and the like, butterfly valve shaft seals , butterfly valve shaft seals, stern tube seals, fuel hoses, gaskets, engine O-rings, marine cables, marine oil seals, marine shaft seals and the like.

[0387] In the field of chemical products, such as chemical plants, and the pharmaceutical field, such as pharmaceuticals, the molded product can be used in a process requiring a high level of chemical resistance, such as a process for the production of chemical products, such as pharmaceuticals, agrochemicals, paints and varnishes and resins.

[0388] Specific examples of use in the chemical and pharmaceutical fields include seals used for chemical devices, chemical pumps and flow meters, chemical piping, heat exchangers, agrochemical sprayers, agrochemical transfer pumps, gas pipelines, fuel cells, analytical equipment, and physical and chemical equipment, (for example, column fittings and the like, analytical equipment and measuring equipment), flue gas desulfurization compensation devices, nitric acid plants, power plant turbines and the like, seals used for medical sterilization processes, seals for electroplating solutions, belt roll seals for paper production and wind tunnel joint seals; O-rings used for chemical apparatus such as reactors and stirrers, analytical and instrumentation equipment, chemical pumps, pump housings, valves and tachometers, O-rings for mechanical seals and O-rings for compressor sealing; attachments used for high temperature vacuum dryers and pipe connections, and the like, gas chromatographs and pH meters, and glass cooler attachments for sulfuric acid production devices; diaphragms used for diaphragm pumps, analytical equipment, physical and chemical equipment and the like; gaskets used for analytical and measuring equipment; tips for analytical and measuring equipment; valve seats; U-shaped cups; linings of chemical devices, gas tanks, wind tunnels and the like, as well as corrosion-resistant linings of alumite processing tanks; coatings of masking devices for electroplating; fittings for analytical equipment and physical and chemical equipment; compensators for flue gas desulfurization installations; hoses resistant to acids such as concentrated sulfuric acid, chlorine gas transfer hoses, oil-resistant hoses and rainwater drainage hoses for benzene or toluene storage tanks; chemically resistant tubes for analytical equipment and physical and chemical equipment, medical tubes; trichlorethylene-resistant fiber dyeing rollers and dyeing rollers; stoppers for pharmaceuticals; medical rubber plugs; chemical solution bottles, chemical solution tanks, chemical bags and containers; and acid- and solvent-resistant protective equipment such as gloves and dust guards.

[0389] In the field of photography, such as developers, the field of printing, such as printing machines, and the field of coloring, such as dyeing equipment, the molded article can be used as any member of rollers, belts, seals, valve components and the like, dry-dry copiers manifestation.

[0390] Specific examples of use in the fields of photography, printing, and inking include: surface layers of copier transfer rollers, copier cleaner blades, and copier belts; rollers (such as locking rollers, crimp rollers and pinch rollers) and belts for OA equipment such as copiers, printers and fax machines; PPC copier shafts, shafts and belts; rollers of developing machines for film and developing machines for X-ray photographic film; printing rollers, scrapers, tubes, valve components and printing machine belts; printer ink tubes, rolls and belts; paint rollers, scrapers, tubes and valve components for coating and painting equipment; and processing rollers, gravure rollers, guide rollers, magnetic tape coating line guide shafts, magnetic tape coating line engraving shafts and coating rollers.

[0391] In the field of food equipment, including food processing equipment and household products, the molded product can be used in food manufacturing processes and for food handling equipment or food storage equipment.

[0392] Specific examples of use in the food equipment field include plate heat exchanger seals, vending machine solenoid valve seals, thermopot seals, sanitary pipe seals, pressure cooker seals, boiler seals, gaskets for heat exchangers, diaphragms and packings for food processing devices, and rubber materials ( for example, various seals such as heat exchanger gaskets, diaphragms and O-rings, pipelines, hoses, sanitary packings, valve packings and filling packings used as connections between bottle necks and the like, and filler during filling) for processing machines food products. Examples also include packings, gaskets, tubing, diaphragms, hoses and couplings used for products such as alcoholic and non-alcoholic beverages, dispensers, food sterilizers, brewers, boilers, various food vending machines and things like that.

[0393] In the field of nuclear power plant equipment, the molded article can be used for check valves and pressure relief valves around nuclear reactors, seals for uranium hexafluoride concentration devices, and the like.

[0394] Specific examples of use in the general industrial field include sealing materials for hydraulic equipment such as machine tools, construction machines, and hydraulic machines; seals in general and bearing seals of hydraulic and lubrication machines; sealing materials used for mandrels, and the like; seals for windows and the like for dry cleaners; conventional seals and (vacuum) seals for cyclotron valves, proton accelerator seals, automatic packaging machines seals, pump diaphragms for sulfurous acid and chlorine gas analyzers in air (contamination measuring instruments), screw pump linings, printer rolls and belts, belts (conveyor belts) for transportation, squeezing rolls for pickling iron plates and the like, robot cables, solution squeezing rolls of aluminum rolling lines and the like, coupling O-rings, acid-resistant gasket materials, dust seals and the like, rubber cuffs for sliding parts of cutting machines, waste incineration plant gaskets, friction materials, modifiers of metal or rubber surfaces and facing materials. The molded product can also be used as any of the lining and sealing materials of devices used in papermaking processes, sealants for filtration units for clean rooms, sealants for construction, protective coatings for concrete, cement and the like, materials for impregnation of fiberglass, processing aids for polyolefins, formability additives for polyethylene, for fuel tanks of small generators, lawn mowers and the like, and for pre-coated metals obtained by priming metal plates. In addition, the formed product can be used as any sheets and tapes, impregnating fabrics with them and firing them.

[0395] Specific examples of use in the iron and steel industry include rolls for processing steel sheet in iron sheet processing plants.

[0396] Specific examples of use in the electrical field include insulating oil caps of Shinkansen bullet trains, liquid seal transformer vent seals, transformer seals, oil well cable sheaths, furnace seals such as electric furnaces, microwave oven window frame seals, sealing materials used for CRT wedge and neck joints, halogen lamp sealing materials, electrical component retainers, shielded heater lead sealing materials, and sealing materials used for insulating and moisture-proofing electrical equipment wire lead treatments. The molded product can also be used for coating materials for oil and heat resistant electrical wires, high temperature resistant electrical wires, chemical resistant electrical wires, high insulation electrical wires, high voltage power lines, cables, electrical wires used for geothermal power generation devices, electrical wires used around car engines, and the like. The molded product can also be used for vehicle cable seals and shafts. In addition, the molded product can also be used for electrical insulating materials (such as insulating pads of various types of electrical equipment, insulating tapes used on joints, terminals and the like, cables and materials used for heat shrink tubing and the like), and materials for electrical and electronic equipment used in high temperature atmospheres (for example, lead wire materials for motors and electrical wire materials around high temperature furnaces). In addition, the formed product can also be used for encapsulation layers and protective films (back sheets) of solar cells.

[0397] In the field of fuel cells, the molded article can be used as any of the sealing materials between electrodes or between an electrode and a separator in polymer electrolyte fuel cells, phosphoric acid fuel cells and the like, as well as seals, packing, separators and the like, pipelines for hydrogen, oxygen, generated water and the like.

[0398] In the field of electronic components, the molded article can be used as raw materials for heat-emitting materials, raw materials for electromagnetic wave shielding, pads for hard disk drives (magnetic recording devices) of computers, and the like. The molded product can also be used as any of the shock-absorbing rubbers (emergency plugs) of hard drives, binders for electrode active materials of nickel-metal hydride batteries, binders for active materials of lithium-ion batteries, polymer electrolytes of lithium batteries, binders for positive electrodes of alkaline batteries batteries, binders for EL cells (electroluminescent cells), binders for electrode-active materials of capacitors, sealing agents, sealants, quartz coating materials for optical fibers, films and sheets such as optical fiber coating materials, pottings, coatings and adhesive seals for electronic components and printed circuit boards such as CMOS electronic circuits, transistors, integrated circuits, organic transistors, light emitting elements, actuators, memories, sensors, coils, capacitors and resistors, as fixing agents for electronic components, modifiers for encapsulation agents such as epoxy resins, PCB coating agents, modifiers for PCB prepreg resins such as epoxy resins, anti-dissipation materials for light bulbs and the like, gaskets for computers, cooling hoses for large computers, seals such as gaskets and O-rings for secondary batteries, especially for lithium secondary batteries, as encapsulating layers to cover one or both outer surfaces of organic EL structures, connectors and dampers.

[0399] In the field of chemical agent transport equipment, the molded product can be used for safety valves and loading valves of trucks, trailers, tankers, shipping and the like.

[0400] In the field of equipment components for exploration and production of energy resources such as oil and gas, the molded article is used as any of various sealing materials used in the production of oil, natural gas and the like, and used electrical connector boots in oil wells .

[0401] Specific examples of use in the field of energy exploration and production equipment components include drill bit seals, pressure control diaphragms, horizontal drilling motor (stator) seals, stator bearing (shaft) seals, sealing materials used in blowout preventers. (preventers), sealing materials used in rotary blowout preventers (pipe cleaners), sealing materials and gas-liquid connectors used in measurement while drilling (MWD) systems, logging tool seals (such as O-rings, seals, packings, gas-liquid connectors couplings and boots) used in logging devices (logging equipment), expansion packers and completion packers, and packers used for them, seals and packings used in cementing devices, seals used in rock drills (drilling rigs), seals, packings and motor linings are used in mud pumps, geophone covers, U-cups, composite cups, rotary seals, multi-layer elastomeric bearings, flow control seals, sand volume control seals, safety valve seals, hydraulic fracturing device seals (equipment for hydraulic fracturing), seals and packings for linear packers and linear hangers, wellhead seals and packings, choke and valve seals and packings, sealing materials for logging while drilling (LWD) systems, diaphragms (e.g. lube oil supply diaphragms for oil production quarries and the like) used in oil exploration and production, in valves, electronic shoes and sealing elements of rock drills.

[0402] In addition, the molded product can also be used to seal seams in kitchens, bathrooms, toilets and the like; in coated fabrics for camping tents; when printing for stamp materials; in rubber hoses for gas heat pumps and freon-resistant rubber hoses; in films, linings and weather-resistant coatings for agriculture; in containers made of laminated steel sheets and the like, used in construction and household appliances; etc.

[0403] In addition, the molded product can also be used as a metal bonded product such as aluminum. Examples of such uses include door seals, gate valves, pendulum valves and solenoid tips, as well as metal-bonded piston seals and diaphragms, and metal-bonded metal rubber components such as metal gaskets.

[0404] In addition, the molded product can also be used to make rubber components, brake shoes, brake pads and the like, bicycles.

[0405] The molded product may also be used for belts.

[0406] Examples of belts include the following: transmission belts (including flat belts, V-belts, ridge belts, timing belts and the like) and conveyor belts (conveyor belts), such as flat belts used for various applications subject to high temperature, for example, near the engines of agricultural machines, machine tools and industrial machines; belt conveyors for transporting bulk or solid materials such as coal, crushed rock, earth and sand, ores, wood chips and the like, under high temperature conditions; conveyor belts used in metallurgical plants, for example for blast furnaces; conveyor belts for use in high ambient temperatures in precision equipment assembly plants, food factories, etc.; V-belts and serpentine belts for agricultural machinery, general purpose equipment (such as OA equipment, printing machines and commercial dryers), automobiles and the like; drive belts for mobile robots; timing belts, such as drive belts of food machines and machine tools; and timing belts used in automobiles, OA equipment, medical applications and printing machines.

[0407] In particular, representative examples of timing belts for automobiles include timing belts.

[0408] Belts may have a single-layer structure or a multi-layer structure.

[0409] In the case of a multi-layer structure, the belts may consist of a layer obtained by cross-linking the stitchable composition and a layer consisting of additional material.

[0410] Examples of the layer consisting of additional material in multi-layer belts include layers consisting of additional rubber, layers consisting of thermoplastic resin, various fiber-reinforced layers, scrims, and metal foil layers.

[0411] The molded article can also be used to make industrial anti-vibration pads, anti-vibration mats, slab mats for railways, gaskets, anti-vibration rubbers for automobiles and the like. Examples of anti-vibration rubbers for automobiles include anti-vibration rubbers for engine mounts, engine mounts, beam mounts, strut mounts, bushings, shock absorbers, muffler mounts, center bearings and the like.

[0412] Examples of other uses include connecting elements such as flexible joints and expansion joints, boots and bushings. In the shipping field, examples include marine pumps.

[0413] Connectors refer to connections used in piping and piping equipment, and are used in applications such as preventing vibration and noise generated by piping systems, absorbing expansion and contraction or displacement caused by temperature changes or pressure changes, absorbing dimensional changes, mitigation and prevention of the consequences of earthquakes and ground subsidence.

[0414] Flexible joints and expansion joints may be advantageously used as, for example, complex-shaped moldings for shipbuilding piping, pump and compressor equipment piping, chemical plant piping, electrical wiring, construction and waterworks piping, automobiles, and the like.

Boots may preferably be used as, for example, complex shaped molded products such as boots for various industries, including boots for automobiles, such as constant velocity joint boots, dust boots, rack and pinion steering boots, pin boots, and piston boots. , boots for agricultural machines, boots for industrial vehicles, boots for construction machines, boots for hydraulic machines, boots for pneumatic machines, boots for centralized lubrication machines, boots for pumping liquids, boots for fire extinguishing, boots for pumping various liquefied gases.

[0415] The molded article can also be used to make diaphragms for filter presses, diaphragms for blowers, diaphragms for water supply, diaphragms for liquid storage tanks, diaphragms for pressure switches, diaphragms for batteries, diaphragms for air springs such as suspensions, etc.

[0416] By combining a molded article and a rubber or resin, an anti-slip agent can be obtained to obtain a molded article or coating film that is not slippery in an environment that is wetted by water, such as rain, snow, ice, or sweat.

[0417] The molded article can also be used, for example, as a hot-pressing liner material in the production of decorative plywood, printed circuit boards, electrical insulation boards, rigid polyvinyl chloride laminates of melamine resins, phenolic resins, epoxy resins, and the like.

[0418] In addition, the molded article can also help impart impermeability to various substrates, such as gun gaskets and clothing to protect against contact with harsh chemicals.

[0419] The molded product can also be used to make O-rings, V-rings, X-rings, seals, gaskets, diaphragms, oil seals, bearing seals, lip seals, plunger seals, door seals, lip seals, and end seals. seals, gas supply plate seals, base plate seals, barrel seals and other various sealing materials used to seal or encapsulate lubricating oils (such as engine oils, workstation oils and transmission oils), fuel oils and greases (especially urea-based lubricants) containing amine-type additives (in particular, amine-type additives used as antioxidants and detergent dispersants) used in transportation systems such as automobiles and ships, and they can also be used as any tubes, hoses, various rubber rollers, coatings, belts, valve bodies and the like. The molded product can also be used as any of the laminating materials and facing materials.

[0420] The molded article can also be used to cover heat and oil resistant electrical wires used, for example, as electrical input wires for sensors that contact transmission oil and/or engine oil and detect oil temperatures and/or oil pressures in internal combustion engines of automobiles and the like, and they can also be used in high-temperature oil atmosphere, such as in the oil pan of an automatic transmission or engine.

[0421] In addition, the molded article can be used after forming a vulcanized film thereon. Specific examples of such applications include non-stick oil-resistant rollers for copiers, weather-resistant seals to prevent ice formation, rubber stoppers for infusion solutions, rubber stoppers for vials, mold release agents, non-stick lightweight shipping belts, anti-stick coatings on automotive engine mount pulley spacers, means for treating coatings made of synthetic fibers, as well as bolted elements or connections having a thin layer of sealing coating.

[0422] It should be noted that the use of the molded article in automotive components also includes the use as components of motorcycles having the same design.

[0423] Examples of fuels in the automotive field include diesel fuel, gasoline, and diesel engine fuel (including biodiesel).

[0424] The molded article can also be used as a sealing material for rolling bearings.

[0425] Examples of rolling bearings include a ball bearing, a roller bearing, a bearing assembly, and a linear bearing.

[0426] Examples of ball bearings include a deep groove ball bearing, a thrust ball bearing, and a thrust angular contact ball bearing.

[0427] Examples of the deep groove ball bearing include a deep groove ball bearing, an angular contact ball bearing, a four-point contact ball bearing, and a self-aligning ball bearing.

[0428] Deep groove ball bearings are used, for example, in electric motors, household appliances, and OA equipment.

[0429] Examples of angular contact ball bearing include single row angular contact ball bearing, matched angular contact ball bearing and double row angular contact ball bearing, and single row angular contact ball bearing is used in electric motors, household electrical appliances and OA equipment, and hydraulic pumps , vertical pumps and the like, which are subject to axial load in addition to radial load. Angular contact ball bearing with matched installation is used in the main shaft, grinding spindle and the like of the machine tool, which is necessary to improve the rotation accuracy and rigidity of the shaft. Double row angular contact ball bearing is used in electromagnetic clutch of automobile air conditioner and the like.

[0430] A four-point contact ball bearing is used, for example, in a gearbox that accepts axial loads from both directions and does not have much space across the width of the bearing.

[0431] A self-aligning ball bearing is used in areas where it is difficult to align the shaft and housing, on power transmission shafts that bend easily, and the like.

[0432] The thrust ball bearing includes a unidirectional thrust ball bearing and a bidirectional thrust ball bearing, and the molded article is applicable to conventionally known applications in which such ball bearings are used.

[0433] A thrust angular contact ball bearing is used in combination with a double row cylindrical roller bearing to carry the axial load of the main shaft of a machine tool.

[0434] Examples of the roller bearing include a radial roller bearing and a thrust roller bearing.

[0435] Examples of the radial roller bearing include a cylindrical roller bearing, a needle roller bearing, a tapered roller bearing, and a self-aligning roller bearing.

[0436] Cylindrical roller bearings are used in general engineering, machine tools, electric motors, gearboxes, train wheel axles, aircraft and the like.

[0437] Needle roller bearings are used in general engineering, automobiles and electric motors.

[0438] Tapered roller bearing is used in machine tool, automobile and train wheel axle, rolling mill, gearbox and the like.

[0439] Self-aligning roller bearing is used in general machinery, rolling mill, paper machine, wheel axle and the like.

[0440] Examples of the thrust roller bearing include a cylindrical thrust roller bearing, a needle roller thrust bearing, a tapered roller thrust bearing, and a self-aligning thrust roller bearing.

[0441] Cylindrical roller thrust bearing is used in machine tools, general purpose machinery and the like.

[0442] Thrust needle roller bearing is used in automobiles, pumps, general machinery and the like.

[0443] Tapered roller thrust bearing is used in general machinery, rolling mill and the like.

[0444] Thrust self-aligning roller bearing is used in faucets, extruders, general purpose machinery and the like.

[0445] In addition to being cross-linked and used as a molded article, the cross-linkable composition can also be used as various components in various industrial applications. Therefore, applications of the crosslinkable composition will now be described.

[0446] The cross-linkable composition can be used, for example, for surface modifiers of metals, rubbers, plastics, glass and the like; for sealing and coating materials that must be heat-resistant, chemical-resistant, oil-resistant and non-stick, such as metal gaskets and seals; for non-stick coating materials for rollers, belts and the like, for OA equipment or leak barriers; and for coating woven sheets and tapes by impregnation and firing.

[0447] The surface crosslinkable composition can be used as a sealing material, gasket and complex-shaped sealant in a conventional manner by obtaining high viscosity and high concentration; can be used to form a thin film several microns thick due to its low viscosity; and it can be used to coat pre-coated metal, O-ring, diaphragm and reed valve because it has medium viscosity.

[0448] In addition, the cross-linkable composition can also be used to coat conveyor rolls or belts for woven fabrics or paper sheets, printing tapes, chemical resistant tubing, chemical plugs and fuel hoses.

[0449] The following metals, such as iron, stainless steel, copper, aluminum and brass, can be used as substrates for articles to be coated with the cross-linkable composition; glass products such as glass plates and woven and non-woven materials made from glass fibers; molded products and products coated with versatile and heat-resistant resins such as polypropylene, polyoxymethylene, polyimide, polyamideimide, polysulfone, polyethersulfone and polyetherketone; molded products and products coated with general purpose rubbers such as SBR, butyl rubber, NBR and EPDM, and heat-resistant rubbers such as silicone rubber and fluoroelastomer; fabrics and non-woven materials made of natural and synthetic fibers and the like.

[0450] Coated products formed from a cross-linkable composition can be used in applications where heat resistance, solvent resistance, lubricity and non-stickiness are required, and specific examples of applications include rolls (such as fixing rolls and corrugated rolls) and conveyor belts for OA equipment such as copiers, printers and fax machines; sheets and belts; and O-rings, diaphragms, chemical resistant tubing, fuel hoses, valve seals, chemical plant gaskets, engine system gaskets and the like.

[0451] The cross-linkable composition can also be used as a coating material or adhesive by dissolving in a solvent. The cross-linkable composition can also be used as a coating material since it is produced as an emulsified dispersion (latex).

[0452] The cross-linkable composition is used as any of the sealing materials and gaskets for various devices, pipelines and the like; agents for treating the surface of structures consisting of inorganic and organic substrates such as metals, ceramics, glass, stone, concrete, plastic, rubber, wood, paper and fibers; etc.

[0453] The cross-linkable composition can be applied to substrates and the like by dispenser coating or screen printing.

[0454] The cross-linkable composition can be used as a coating composition for film casting or for dipping a substrate such as fabric, plastic, metal or elastomer.

[0455] In particular, the cross-linkable composition can be used in latex form to make upholstery fabrics, protective gloves, impregnated fibers, O-ring coatings, fuel system quick release O-ring coatings, fuel system seal coatings, fuel tank tilt valve diaphragm coatings, coatings for diaphragms of fuel tank pressure sensors, coatings for oil and fuel filter seals, coatings for fuel tank sensor seals and sensor head seals, coatings for fuser mechanism shafts of copiers, polymer paint and varnish compositions.

[0456] These compositions are suitable for use in coating silicone rubbers, nitrile rubbers and other elastomers. To improve both the penetration resistance and chemical resistance of the substrate elastomers, as well as heat resistance, they are also suitable for use in coating components made from such elastomers. Other applications include coatings for heat exchangers, expansion joints, tanks, reservoirs, fans, chimneys and other piping, as well as storage structures such as concrete warehouse structures. The cross-linkable composition may be applied to the open cross-section of a multilayer composite structure, for example, in a method for making a hose and diaphragm structure. The sealing element at the joint and joint is often made of a hard material, and the cross-linking composition provides an improved frictional interface and improved dimensional interference fit with reduced leakage along the sealing surface. Its latex increases the durability of seals in various automotive systems.

[0457] They can also be used in the manufacture of power steering systems, fuel systems, air conditioning systems and any connections where hoses and tubes connect to other components. The cross-linkable composition is also useful for repairing manufacturing defects (and damage caused by use) in a multi-layer rubber structure, such as a three-layer fuel hose. The cross-linkable composition is also suitable for coating a thin steel plate, which may be formed or stamped before or after application of the coating material. For example, multiple layers of coated steel can be assembled to form a spacer between two rigid metal elements. The sealing effect is obtained by applying a cross-linkable composition between these layers. This process can be used to produce engine head gaskets and exhaust manifold gaskets to reduce bolt forces and distortion of assembled components, while providing good fuel economy and low emissions by reducing cracking, deflection and bore distortion.

[0458] In addition, the cross-linkable composition can also be used as any of the following: coating agents; substrate-embedded gaskets and packings obtained by dispensing and forming on substrates containing inorganic materials such as metals and ceramics; multilayer articles formed by coating substrates containing inorganic materials such as metals and ceramics; etc.

[0459] The cross-linkable composition is also suitable as a conductor material for electronic devices that are lightweight and flexible, and it can be used in known electronic components. Examples include electronic components such as CMOS electronic circuits, transistors, integrated circuits, organic transistors, light-emitting elements, actuators, memories, sensors, coils, capacitors, and resistors. Through their use, flexible electronic devices such as solar cells, various displays, sensors, actuators, electronic artificial skin, sheet scanners, Braille displays and wireless power transmission sheets can be obtained.

[0460] While embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

Examples

[0461] In the following, embodiments of the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

[0462] Various numerical values in the examples are measured in the following ways.

[0463] <Oxygen concentration in reactor>

The gas discharged from the injection gas line connected to the reactor is measured and analyzed by a low concentration oxygen analyzer (trade name "PS-820-L", manufactured by Iijima Electronics Corporation) to thereby determine the oxygen concentration in the reactor during polymerization.

[0464] <Polymer concentration>

In a vacuum dryer, about 1 g of an aqueous polymer solution is dried at 60°C for 60 minutes, the mass of the heated residue is measured, and the ratio of the mass of the heated residue to the mass of the aqueous polymer solution (1 g) is expressed as a percentage and taken as the polymer concentration.

[0465] <Weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer>

Weight average molecular weight and number average molecular weight of the polymer were determined by gel permeation chromatography (GPC) using a 1260 Infinity II column from Agilent Technologies, Inc. (TSKgel G3000PW _XL × 1 column) from Tosoh Corporation, a mixed solvent of Tris buffer and acetonitrile (Tris buffer:acetonitrile=8:2(v/v)) was supplied as solvent at a flow rate of 0.5 mL/min, and also monodisperse polyethylene oxide (PEO) and polyethylene glycol (PEG) as standards.

[0466] <Solid concentration of aqueous dispersion containing fluorine-containing elastomer>

In an air dryer, 1 g of an aqueous dispersion containing a fluorine-containing elastomer is dried at 150°C for 180 minutes, the mass of the heated residue is measured and the mass fraction (wt%) of the heated residue relative to the mass of the aqueous dispersion (1 g) is determined as the concentration of the solid in the aqueous solution.

[0467] <Fluorine elastomer composition>

The composition of the fluorine-containing elastomer is determined using NMR analysis.

[0468] <Mooney Viscosity>

Mooney viscosity is measured at 100°C according to JIS K 6300-1.2013 using a Mooney viscometer MV 2000E manufactured by ALPHA TECHNOLOGIES.

[0469] <Polymer Adhesion Proportion>

The ratio (adhesion ratio for the polymerization tank) of the mass of polymer deposits adhered to the polymerization tank after completion of polymerization to the total amount of polymer (fluorine-containing elastomer) after completion of polymerization is determined by the following formula.

Polymer adhesion fraction (% mass) = weight of polymer deposits/weight of resulting polymer (including polymer deposits) × 100

Mass of polymer produced = mass of aqueous dispersion × solids concentration (% wt) of aqueous dispersion/100 + mass of polymer deposits

Polymer deposits include polymer adhered to the interior of the polymerization tank, such as the inner wall of the polymerization tank and the stirrer blades, after removing the aqueous dispersion from the polymerization tank after completion of polymerization, as well as polymer that is released from the aqueous dispersion due to aggregation and is suspended or sedimented without dispersing in an aqueous dispersion. The mass of polymer deposits is the mass after the water contained in the polymer deposits has been removed by drying at 120°C.

[0470] <Polymerization speed>

The polymerization rate is calculated using the following formula:

Polymerization rate={weight of aqueous dispersion × solid concentration/100}/{(amount of pure water used in polymerization+amount of water contained in aqueous solution of polymer (1) used in polymerization) × polymerization time}

The units of the corresponding quantities in the formula are as follows.

Weight of aqueous dispersion: g

Solid concentration: %wt

Amount of pure water used during polymerization: kg

Amount of water contained in the aqueous polymer solution (1) used during polymerization: kg

Curing time: hour

Curing rate: g/(hour × kg)

[0471] <Average particle size>

The average particle size (cumulant average diameter) of fluorine-containing elastomer particles in an aqueous dispersion is calculated using the cumulant method by performing dynamic light scattering measurement using an ELSZ-1000S (manufactured by Otsuka Electronics Co., Ltd.).

[0472] <Number of fluorinated elastomer particles in aqueous dispersion>

The number of fluorine elastomer particles in the aqueous dispersion was calculated using the following expression:

[0473]

[0474] where the average particle size is the cumulative average size calculated using the method described above, and the number of polymer particles (the number of particles of fluorine-containing elastomer) is the number of particles per 1 cm ³ of water, and the relative density of all fluorine-containing elastomers in the examples is 1.8.

[0475] Receipt example 1

Ammonium persulfate (APS) is added to 110 g of monomer A represented by the formula CF ₂ =CFOCF ₂ CF ₂ COOH and 220 g of water and the mixture is stirred at 52°C for 96 hours under a nitrogen atmosphere to obtain an aqueous solution of A- 1 polymer A, containing as polymer A the homopolymer CF ₂ =CFOCF ₂ CF ₂ COOH. Additional APS is added as needed during the reaction, and a total of 5 mol% is used. The oxygen concentration in the reactor ranges from 11 to 61 ppm. According to GPC analysis of the resulting aqueous solution A-1 of polymer A, polymer A has a Mw of 1.5 × 10 ⁴ and a Mn of 1.0 × 10 ⁴ . Water is added to the resulting aqueous solution A-1 of polymer A to bring the concentration to 2.2% by weight (polymer A, aqueous solution A-2).

[0475] Cooking example 1

Ammonium persulfate (APS) is added to 110 g of monomer A represented by the formula CF ₂ =CFOCF ₂ CF ₂ COOH and 220 g of water, and the mixture is stirred at 52°C for 96 hours under a nitrogen atmosphere to obtain an aqueous solution A -1 polymer A, containing as polymer A the homopolymer CF ₂ =CFOCF ₂ CF ₂ COOH. Additional APS is added as needed during the reaction, and a total of 5 mol% is used. The oxygen concentration in the reactor ranges from 11 ppm. volumetric up to 61 volumetric. According to GPC analysis of the resulting aqueous solution A-1 of polymer A, polymer A has a Mw of 1.5 x 10 ⁴ and a Mn of 1.0 x 10 ⁴ . Water is added to the resulting aqueous solution A-1 of polymer A to bring the concentration to 2.2% by weight (polymer A, aqueous solution A-2).

[0476] Cooking example 2

Add thirty grams of monomer B represented by the formula CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ COOH, 60 g of water, 0.5 eq. NH ₃ (in an amount corresponding to 0.5 equivalent with respect to monomer B) and 2% mol APS, and stirred at 52°C for 72 hours under a nitrogen atmosphere to obtain an aqueous solution B-1 of polymer B containing polymer B , homopolymer CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ COOH. The oxygen concentration in the reactor ranges from 20 ppm. volume up to 50 ppm volume. According to the GPC analysis of the resulting aqueous solution B-1 of polymer B, the aqueous solution B has a Mw of 1.4 × 10 ⁴ and a Mn of 0.9 × 10 ⁴ . Add water and 0.4 eq. NH ₃ (in an amount corresponding to 0.4 equivalents with respect to monomer B used for polymerization) to obtain aqueous solution B-1 of polymer B to bring the concentration to 1.9% by weight (polymer B aqueous solution B-2).

[0477] Example 1

First, 1.466 g of deionized water and 34.09 g of Polymer A of A-2 aqueous solution (2.2 wt%) were added to a SUS polymerization tank with an internal volume of 3 L. The polymerization tank is sealed and the system is purged with nitrogen to remove oxygen. The temperature of the polymerization tank is raised to 80°C and monomers (starting monomers) are introduced under pressure at a molar ratio of vinylidene fluoride (VDF)/tetrafluoroethylene (TFE)/hexafluoropropylene (HFP) = 19/11/70 (% mol) with stirring, so that the internal the pressure in the polymerization tank reached 1.47 MPa g.

[0478] Next, an aqueous polymerization initiator solution prepared by dissolving 0.026 g of ammonium persulfate (APS) in deionized water is introduced under nitrogen gas pressure to initiate polymerization. When the internal pressure drops to 1.45 MPa g. As polymerization progresses, mixed monomer VDF/TFE/HFP (= 50/20/30% mol) is charged so that the internal pressure is constantly at 1.47 MPa mang.

[0479] When 14 g of mixed monomer is added, 2.19 g of diiodine compound I(CF ₂ ) ₄ I is introduced under nitrogen gas pressure.

[0480] At each time 3.0 hours, 6.0 hours and 9.0 hours after initiation of polymerization, an aqueous solution of polymerization initiator is introduced under pressure of nitrogen gas containing 0.026 g of APS.

[0481] When 477 g of mixed monomer is added, stirring is stopped and the pressure is reduced until the pressure in the polymerization tank decreases to atmospheric pressure. The polymerization tank is cooled to obtain an aqueous dispersion. The results are shown in Table 1.

[0482] An aqueous solution of aluminum sulfate is added to the aqueous dispersion to effect coagulation. The resulting coagulated product is washed with water and dried to obtain a fluorine-containing elastomer. The Mooney viscosity of the fluorine-containing elastomer is ML1+10 (100°C)=54.9. The copolymer composition determined by NMR analysis is VDF/TFE/HFP=50/20/30 (% mol).

[0483] Example 2

The experiment is carried out under the same conditions as in Example 1, except that 34.09 g of polymer A aqueous solution A-2 (2.2% by weight) is neutralized with aqueous ammonia to pH 5.6 before adding to the polymerization tank .

[0484] The polymerization tank is cooled to obtain an aqueous dispersion. The results are shown in Table 1.

[0485] An aqueous solution of aluminum sulfate is added to the aqueous dispersion to effect coagulation. The resulting coagulated product is washed with water and dried to obtain a fluorine-containing elastomer. The Mooney viscosity of the fluorine-containing elastomer is ML1+10 (100°C)=54.7. The copolymer composition determined by NMR analysis is VDF/TFE/HFP=50/20/30 (% mol).

[0486] Example 3

The experiment is carried out under the same conditions as in Example 1, except that the amount of deionized water used is 1460 g, and 40.32 g of aqueous solution B-2 of polymer B (1.9% by weight) is added to the polymerization tank instead of 34.09 g of an aqueous solution A-2 of polymer A (2.2% by weight), and each time after 3.0 hours and 6.0 hours after the initiation of polymerization, an aqueous solution of a polymerization initiator containing 0.026 g of APS is introduced under nitrogen gas pressure .

[0487] The polymerization tank is cooled to obtain an aqueous dispersion. The results are shown in Table 1.

[0488] An aqueous solution of aluminum sulfate is added to the aqueous dispersion to effect coagulation. The resulting coagulated product is washed with water and dried to obtain a fluorine-containing elastomer. The Mooney viscosity of the fluorine-containing elastomer is ML1+10 (100°C)=63.9. The copolymer composition determined by NMR analysis is VDF/TFE/HFP=50/20/30 (% mol).

[0489]

[Table 1]

Example 1 Example 2 Example 3 Reaction time min 573 706 438 Polymer adhesion fraction % mass 1.62 1.43 1.74 Solid concentration % mass 22.8 22.8 22.8 Weight of aqueous dispersion G 1939 1930 1933 Average particle size nm 197 232 150 Number of particles particles/cm ³ 4.08 × 10 ¹³ 2.48 × 10 ¹³ 9.28 × 10 ¹³ Polymerization speed g/(hour × kg) 30.9 24.9 40.2

[0490] Cross-linking characteristics

Each of the fluorinated elastomers obtained in Examples 1 to 3 was mixed to obtain a fluorinated elastomer composition having the composition shown in Table 2. The cross-linking curve of the resulting fluorinated elastomer composition was determined using a MDRH2030 rubber vulcanization tester (manufactured by M&K Co., Ltd. ) during press cross-linking, and determine the minimum viscosity (ML), maximum torque level (MH), induction time (T10) and optimal cross-linking time (T90). In addition, the fluorine-containing elastomer composition is cross-linked by (press cross-linking and oven cross-linking after press cross-linking to obtain a cross-linked molded sheet of the product.

Mixing method: roller kneading.

Press cross-linking: 160°C for 10 minutes

Cross-linking in oven: 180°C for 4 hours.

[0491] The materials shown in Table 2 are as follows.

Carbon MT: Thermax N-990 from Cancarb Limited.

TAIC: triallyl isocyanurate, TAIC, manufactured by Nihon Kasei CO., LTD.

Perhexa 25B: 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, manufactured by NOF CORPORATION

[0492] Properties in normal state

Using a cross-linked molded product sheet, test specimens having a No. 6 dumbbell shape are prepared in accordance with JIS K 6251 and the 100% modulus (M100), tensile strength (TB) and elongation at break (EB) of the prepared specimens are measured for tests in normal condition.

[0493] Hardness

A dumbbell-shaped test piece No. 6 is prepared in the same manner as above, and the hardness (Shore A) of the prepared test piece is measured in accordance with JIS K 6253 (peak value, 1 sec, 3 sec).

[0494] Compression shrinkage

Using each of the fluorine-containing elastomer compositions, press cross-linking and oven cross-linking are carried out under the above conditions to produce an O-ring (P-24 size), and the compression shrinkage of the prepared O-ring is measured in accordance with JIS. K 6262 at 200°C, 72 hours and 25% compressibility.

[0495] The results are shown in Table 2.

[0496]

[Table 2]

Example 1 Example 2 Example 3 A drug Fluorine elastomer phr
(parts/100 parts) 100 100 100 Carbon MT phr 20 20 20 TAIC phr 4 4 4 Perhexa 25B phr 1.5 1.5 1.5 Cross-linking characteristics M.L. dNm 0.8 0.8 0.9 160°C M.H. dNm 25.9 25.7 25.8 T10 min 1.2 1.2 1.2 T90 min 3.7 3.5 3.4 Cross-linking conditions Cross stitching under pressure 160°C×10 min 160°C×10 min 160°C×10 min Cross-linking in the oven 180°C×4 hours 180°C×4 hours 180°C×4 hours Properties in normal condition M100 MPa 2.9 3.0 2.9 TB MPa 22.4 23.6 20.4 E.B. % 312 325 284 Hardness Peak A Shore spot 69 69 68 Shore A 1 sec spot 67 67 66 Shore A 3 sec spot 65 66 65 Compression shrinkage % 21 23 22

Claims (31)

1. A method for producing an aqueous dispersion of a fluorine-containing elastomer, including the polymerization of a fluorine-containing monomer in the presence of a polymer (1) containing a polymerization unit (1) based on the monomer (1) represented by the general formula (1) and an aqueous medium CF ₂ =CF-R-CZ ¹ Z ² -COOM (1) where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R ⁷ represents H or an organic group, where the amount of added polymer (1) is from 0.0001 to 2% by weight relative to 100% by weight of the aqueous medium, and the ion exchange capacity of the polymer (1) is 0.80 meq/g or more. 2. The production method according to claim 1, wherein the monomer (1) is a monomer (2) represented by the general formula (2): CF ₂ =CF(-O-Rf-COOM) (2) where Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is as defined above. 3. The production method according to claim 1 or 2, wherein the polymer (1) has a weight average molecular weight of 1.4 × 10 ⁴ or more. 4. The production method according to claim 1 or 2, wherein the content of the polymerization unit (1) is 50 mol% or more with respect to all polymerization units constituting the polymer (1). 5. The production method according to claim 1 or 2, in which the polymerization of the fluorine-containing monomer is carried out in the presence of a polymerization initiator, and the amount of added polymerization initiator is from 0.00001 to 10% by weight relative to 100% by weight of the fluorine-containing monomer. 6. The production method according to claim 1 or 2, wherein the polymerization of the fluorine-containing monomer is carried out substantially in the absence of a fluorine-containing surfactant. 7. The production method according to claim 1 or 2, in which the fluorine-containing monomer is vinylidene fluoride or tetrafluoroethylene. 8. The production method according to claim 1 or 2, wherein the fluorine-containing monomer is vinylidene fluoride. 9. The production method according to claim 1 or 2, in which the fluorine-containing elastomer contains -CH ₂ - in the main chain. 10. Composition for producing a molded product containing a fluorine-containing elastomer and a polymer (1) containing a polymerization unit (1) based on a monomer (1) represented by the general formula (1): CF ₂ =CF-R-CZ ¹ Z ² -COOM (1) where R is a linking group, Z ¹ and Z ² are each independently F or CF ₃ and M is H, a metal atom, NR ⁷ ₄ , imidazolium, optionally containing a substituent, pyridinium, optionally containing a substituent, or phosphonium, optionally containing a substituent, where R7 represents H or an organic group, where the amount of added polymer (1) is from 0.0001 to 2% by weight relative to 100% by weight of the aqueous medium, and the ion exchange capacity of the polymer (1) is 0.80 meq/g or more. 11. The composition according to claim 10, where the monomer (1) is a monomer (2) represented by the general formula (2): CF ₂ =CF(-O-Rf-COOM) (2) where Rf represents a fluorine alkylene group containing 1 to 40 carbon atoms, or a fluorine alkylene group containing 2 to 100 carbon atoms and containing an ether linkage or a keto group, and M is as defined above. 12. The composition according to claim 10 or 11, wherein the polymer (1) has a weight average molecular weight of 1.4 x 10 ⁴ or more. 13. The composition according to claim 10 or 11, in which the content of the polymerization unit (1) is 50 mol% or more with respect to all polymerization units constituting the polymer (1). 14. Composition according to claim 10 or 11, which is an aqueous dispersion. 15. The composition according to claim 14, wherein the concentration of solids in the aqueous dispersion is from 5 to 50% by weight relative to the aqueous dispersion. 16. A composition according to claim 10 or 11, which is substantially free of fluorinated surfactant. 17. The composition according to claim 10 or 11, in which the fluorine-containing elastomer contains a vinylidene fluoride unit or a tetrafluoroethylene unit. 18. The composition according to claim 10 or 11, in which the fluorine-containing elastomer contains a vinylidene fluoride unit. 19. The composition according to claim 10 or 11, in which the fluorine-containing elastomer contains -CH ₂ - in the main chain.