Coating composition, coating film, layered product, and coated article

Abstract

Provided is a coating material composition comprising a fluororesin, a polymer (I) containing a polymerization unit (I) derived from a monomer represented by the general formula (I) below, and an aqueous medium, wherein the content of the polymer (I) is 2,000 ppm by mass or less based on the coating material composition: CX¹X³=CX²R(-CZ¹Z²-A⁰)m (I) wherein X¹ and X³ are each independently F, C1, H, or CF₃; X² is H, F, an alkyl group, or a fluorine-containing alkyl group; A⁰ is an anionic group; R is a linking group; Z¹ and Z² are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more. (No suitable figure)

Description

Coating composition, coating film, laminate and coated article

[0001] The present disclosure relates to coating compositions, coatings, laminates and coated articles.

[0002] Polytetrafluoroethylene (PTFE) is excellent in heat resistance, chemical resistance, water and oil repellency, mold releasability, sliding properties, etc. For these reasons, aqueous dispersions containing PTFE are used as mold release agents for molding dies, rolls for office automation (OA) equipment, household products such as irons, kitchen appliances such as frying pans and hot plates, and as coating compositions in the fields of the food industry, electrical industry, machinery industry, etc.

[0003] Patent Document 1 describes an aqueous dispersion composition for a primer for a fluororesin coating layer, which contains (A) a water-soluble and curable polyamideimide-based and / or polyimide-based binder polymer, (B) ceramic spherical particles, (C) modified polytetrafluoroethylene particles, and (D) an aqueous medium, in which the modified polytetrafluoroethylene particles (C) have a melt creep viscosity of 8×10 at 380° C. ９ That's 1.0 x 10 １０ The document describes an aqueous dispersion composition for a primer, characterized by containing modified polytetrafluoroethylene particles having a viscosity in the range of Pa·s or less and a standard specific gravity of 2.146 to 2.170.

[0004] Patent Document 2 describes a laminate comprising a substrate, a primer layer formed on the substrate, the primer layer containing inorganic particles (a) having an average particle size of 3 μm or more and a heat-resistant resin (a) and not containing a fluororesin, an intermediate layer formed on the primer layer, the intermediate layer containing a fluororesin (b) and a heat-resistant resin (b), and a topcoat layer formed on the intermediate layer, the topcoat layer containing a fluororesin (c).

[0005] Patent Document 3 describes a method for producing a fluoropolymer, which comprises a step of obtaining a fluoropolymer by polymerizing a fluoromonomer in an aqueous medium in the presence of a polymer (1) containing polymerized units (1) based on a monomer represented by the following general formula (1): CX ２ =CY(-CZ ２-O-Rf-A) (1) (In the formula, X is the same or different and represents -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and represents -H, -F, an alkyl group or a fluoroalkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. A is -COOM, -SO ３ M or -OSO ３ M (M is —H, a metal atom, —NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group, provided that at least one of X, Y, and Z contains a fluorine atom.

[0006] Patent Document 4 describes a method for producing an aqueous fluoropolymer dispersion, which comprises a step A of subjecting a pre-treatment aqueous dispersion containing a fluoropolymer (excluding the polymer (I)) obtained by polymerization in the presence of a polymer (I) containing polymerized units (I) based on a monomer represented by the following general formula (I) to ultrafiltration, microfiltration, or dialysis membrane treatment, or a combination thereof: CX １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more.

[0007] Japanese Patent No. 4853081 JP 2015-127142 A International Publication No. 2019 / 168183 International Publication No. 2020 / 218620

[0008] An object of the present disclosure is to provide a novel coating composition.

[0009] According to the present disclosure, there is provided a coating composition (sometimes referred to as a "first coating composition" in the present disclosure) containing a fluororesin, a polymer (I) containing polymerized units (I) based on a monomer represented by general formula (I), and an aqueous medium, wherein the content of the polymer (I) in the coating composition is 2000 mass ppm or less. １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more.

[0010] The viscosity of the first coating composition of the present disclosure is preferably 100 mPa·s or more and 1000 mPa·s or less. In the first coating composition of the present disclosure, the content of the fluororesin is preferably 15.0 mass% or more and 52.0 mass% or less, based on the coating composition. In the first coating composition of the present disclosure, the fluororesin is preferably at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, ethylene / tetrafluoroethylene copolymer, and ethylene / chlorotrifluoroethylene copolymer. The stability retention time of the first coating composition of the present disclosure, as measured by a stirring test, is preferably 10 minutes or more. In the first coating composition of the present disclosure, the content of polymer (I) is preferably 0.1 mass ppm or more, based on the coating composition. The first coating composition of the present disclosure preferably further contains a nonionic surfactant.

[0011] The present disclosure also provides a coating composition containing a fluororesin and an aqueous medium, which has a stability retention time of 10 minutes or more as measured by a stirring test and a viscosity of 50 mPa·s or more and 1000 mPa·s or less (sometimes referred to as a "second coating composition" in the present disclosure).

[0012] In the second coating composition of the present disclosure, the content of the fluororesin is preferably 15.0% by mass or more and 52.0% by mass or less, relative to the coating composition. In the second coating composition of the present disclosure, the fluororesin preferably contains at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer. In the second coating composition of the present disclosure, the fluororesin preferably contains at least polytetrafluoroethylene. In the second coating composition of the present disclosure, the content of polytetrafluoroethylene in the coating composition is preferably 60% by mass or more, relative to the fluororesin. In the second coating composition of the present disclosure, the fluororesin preferably contains only tetrafluoroethylene / hexafluoropropylene copolymer, and the content of the fluororesin is preferably 30.0% by mass or more and 50.0% by mass or less, relative to the coating composition. In the second coating composition of the present disclosure, it is preferred that the fluororesin contains only a tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, and that the content of the fluororesin is 30.0 mass% or more and 50.0 mass% or less relative to the coating composition.

[0013] The present disclosure also provides a coating composition (sometimes referred to as a "third coating composition" in the present disclosure) that contains a fluororesin, a nonionic surfactant, an anionic hydrocarbon surfactant, and an aqueous medium, and is substantially free of a fluorine-containing compound that has a hydrophilic group.

[0014] In the third coating composition of the present disclosure, the fluorine-containing compound having a hydrophilic group is preferably an anionic fluorine-containing surfactant containing fluorine in the anionic moiety having a molecular weight of 800 or less. In the third coating composition of the present disclosure, the content of the fluorine-containing compound having a hydrophilic group is preferably 100 mass ppb or less. In the third coating composition of the present disclosure, the fluorine-containing compound having a hydrophilic group is preferably H(CF ２ ) ７ COOM, F(CF２ ) ７ COOM、 F(CF ２ ) ５ COOM、 H(CF ２ ) ６ 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、および、 (In each formula, M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group. ) is preferably a compound represented by the formula (I). In the third coating composition of the present disclosure, the content of the fluororesin is preferably 15.0 mass% or more and 52.0 mass% or less, relative to the coating composition. In the third coating composition of the present disclosure, the fluororesin preferably contains at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer. In the third coating composition of the present disclosure, the fluororesin preferably contains at least polytetrafluoroethylene. In the third coating composition of the present disclosure, the content of polytetrafluoroethylene in the coating composition is preferably 60 mass% or more, relative to the fluororesin.

[0015] The coating composition of the present disclosure (the first, second, and third coating compositions of the present disclosure may be referred to as "the coating compositions of the present disclosure") preferably further contains a film-forming agent. The coating composition of the present disclosure preferably further contains a binder resin, and the binder resin is preferably at least one selected from the group consisting of polyamideimide, polyimide, polyethersulfone, and polyphenylene sulfide.

[0016] The present disclosure also provides a coating film obtained by applying the coating composition. The present disclosure also provides a laminate including the coating film. The present disclosure also provides a coated article including the coating film or the laminate.

[0017] According to the present disclosure, a new coating composition can be provided.

[0018] 1(a) and 1(b) are front and left side views of the impeller used in the stirring test.

[0019] Specific embodiments of the present disclosure will be described in detail below, but the present disclosure is not limited to the following embodiments.

[0020] In the present disclosure, the term "organic group" refers to a group containing one or more carbon atoms or a group formed by removing one hydrogen atom from an organic compound. Examples of the "organic group" include an alkyl group which may have one or more substituents, an alkenyl group which may have one or more substituents, an alkynyl group which may have one or more substituents, a cycloalkyl group which may have one or more substituents, a cycloalkenyl group which may have one or more substituents, a cycloalkadienyl group which may have one or more substituents, an aryl group which may have one or more substituents, an aralkyl group which may have one or more substituents, a non-aromatic heterocyclic group which may have one or more substituents, a heteroaryl group which may have one or more substituents, a cyano group, a formyl group, RaO-, RaCO-, and RaSO. ２ -, RaCOO-, RaNRaCO-, RaCONRa-, RaOCO-, RaOSO ２ -, and RaNRbSO ２- (In these formulas, Ra is independently an alkyl group which may have one or more substituents, an alkenyl group which may have one or more substituents, an alkynyl group which may have one or more substituents, a cycloalkyl group which may have one or more substituents, a cycloalkenyl group which may have one or more substituents, a cycloalkadienyl group which may have one or more substituents, an aryl group which may have one or more substituents, an aralkyl group which may have one or more substituents, a non-aromatic heterocyclic group which may have one or more substituents, or a heteroaryl group which may have one or more substituents; and Rb is independently H or an alkyl group which may have one or more substituents). As the organic group, an alkyl group which may have one or more substituents is preferred.

[0021] In the present disclosure, the term "substituent" refers to a substitutable 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 oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl group, an aliphatic sulfonyloxy group, an aromatic sulfonyloxy group, a heterocyclic sulfonyloxy group, a sulfamoyl group, an aliphatic sulfonamido group, an aromatic sulfonamido group, a heterocyclic sulfonamido group, an amino group, and an aliphatic amino group. groups, aromatic amino groups, heterocyclic amino groups, aliphatic oxycarbonylamino groups, aromatic oxycarbonylamino groups, heterocyclic oxycarbonylamino groups, aliphatic sulfinyl groups, aromatic sulfinyl groups, aliphatic thio groups, aromatic thio groups, hydroxy groups, cyano groups, sulfo groups, carboxy groups, aliphatic oxyamino groups, aromatic oxyamino groups, carbamoylamino groups, sulfamoylamino groups, halogen atoms, sulfamoylcarbamoyl groups, carbamoylsulfamoyl groups, dialiphatic oxyphosphinyl groups, and diaromatic oxyphosphinyl groups.

[0022] The aliphatic group may be saturated or unsaturated and may have a hydroxy group, an aliphatic oxy 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, etc. Examples of the aliphatic group include alkyl groups having a total of 1 to 8, preferably 1 to 4, carbon atoms, such as a methyl group, an ethyl group, a vinyl group, a cyclohexyl group, and a carbamoylmethyl group.

[0023] The aromatic group may have, for example, a nitro group, a halogen atom, an aliphatic oxy 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, etc. Examples of the aromatic group include aryl groups having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms in total, such as a phenyl group, a 4-nitrophenyl group, a 4-acetylaminophenyl group, and a 4-methanesulfonylphenyl group.

[0024] The heterocyclic group may have a halogen atom, a hydroxy group, an aliphatic oxy 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, etc. Examples of the heterocyclic group include 5- or 6-membered heterocycles having a total of 2 to 12, preferably 2 to 10, carbon atoms, such as a 2-tetrahydrofuryl group and a 2-pyrimidyl group.

[0025] The acyl group may have an aliphatic carbonyl group, an arylcarbonyl group, a heterocyclic carbonyl group, a hydroxy group, a halogen atom, an aromatic group, an aliphatic oxy 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, etc. Examples of the acyl group include acyl groups having a total of 2 to 8, preferably 2 to 4, carbon atoms, such as an acetyl group, a propanoyl group, a benzoyl group, and a 3-pyridinecarbonyl group.

[0026] The acylamino group may have an aliphatic group, an aromatic group, a heterocyclic group, etc., such as an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propanoylamino group, etc. Examples of the acylamino group include acylamino groups having a total of 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, and alkylcarbonylamino groups having a total of 2 to 8 carbon atoms, such as an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propanoylamino group, etc.

[0027] The aliphatic oxycarbonyl group may be saturated or unsaturated and may have a hydroxy group, an aliphatic oxy 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, etc. Examples of the aliphatic oxycarbonyl group include alkoxycarbonyl groups having a total of 2 to 8, preferably 2 to 4, carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a (t)-butoxycarbonyl group.

[0028] The carbamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, etc. Examples of the carbamoyl group include an unsubstituted carbamoyl group, an alkylcarbamoyl group having a total of 2 to 9 carbon atoms, preferably an unsubstituted carbamoyl group, or an alkylcarbamoyl group having a total of 2 to 5 carbon atoms, such as an N-methylcarbamoyl group, an N,N-dimethylcarbamoyl group, or an N-phenylcarbamoyl group.

[0029] The aliphatic sulfonyl group may be saturated or unsaturated and may have a hydroxy group, an aromatic group, an aliphatic oxy 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, etc. Examples of the aliphatic sulfonyl group include alkylsulfonyl groups having a total of 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, such as a methanesulfonyl group.

[0030] The aromatic sulfonyl group may have a hydroxy group, an aliphatic group, an aliphatic oxy 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, etc. Examples of the aromatic sulfonyl group include arylsulfonyl groups having a total of 6 to 10 carbon atoms, such as a benzenesulfonyl group.

[0031] The amino group may have an aliphatic group, an aromatic group, a heterocyclic group, or the like.

[0032] The acylamino group may have, for example, an acetylamino group, a benzoylamino group, a 2-pyridinecarbonylamino group, a propanoylamino group, etc. Examples of the acylamino group include acylamino groups having a total of 2 to 12 carbon atoms, 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, a 2-pyridinecarbonylamino group, a propanoylamino group, etc.

[0033] The aliphatic sulfonamide group, aromatic sulfonamide group, and heterocyclic sulfonamide group may be, for example, a methanesulfonamide group, a benzenesulfonamide group, or a 2-pyridinesulfonamide group.

[0034] The sulfamoyl group may have an aliphatic group, an aromatic group, a heterocyclic group, etc. Examples of the sulfamoyl group include a sulfamoyl group, an alkylsulfamoyl group having 1 to 9 carbon atoms in total, a dialkylsulfamoyl group having 2 to 10 carbon atoms in total, an arylsulfamoyl group having 7 to 13 carbon atoms in total, and a heterocyclic sulfamoyl group having 2 to 12 carbon atoms in total, more preferably a sulfamoyl group, an alkylsulfamoyl group having 1 to 7 carbon atoms in total, a dialkylsulfamoyl group having 3 to 6 carbon atoms in total, an arylsulfamoyl group having 6 to 11 carbon atoms in total, and a heterocyclic sulfamoyl group having 2 to 10 carbon atoms in total, such as a sulfamoyl group, a methylsulfamoyl group, an N,N-dimethylsulfamoyl group, a phenylsulfamoyl group, and a 4-pyridine sulfamoyl group.

[0035] The aliphatic oxy group may be saturated or unsaturated and may have a methoxy group, an ethoxy group, an i-propyloxy group, a cyclohexyloxy group, a methoxyethoxy group, etc. Examples of the aliphatic oxy group include alkoxy groups having a total of 1 to 8, preferably 1 to 6, carbon atoms, such as a methoxy group, an ethoxy group, an i-propyloxy group, a cyclohexyloxy group, and a methoxyethoxy group.

[0036] The aromatic amino group and heterocyclic amino group may have an aliphatic group, an aliphatic oxy group, a halogen atom, a carbamoyl group, a heterocyclic group fused with the aryl group, or an aliphatic oxycarbonyl group, preferably an aliphatic group having 1 to 4 carbon atoms in total, an aliphatic oxy group having 1 to 4 carbon atoms in total, a halogen atom, a carbamoyl group having 1 to 4 carbon atoms in total, a nitro group, or an aliphatic oxycarbonyl group having 2 to 4 carbon atoms in total.

[0037] The aliphatic thio group may be saturated or unsaturated and includes alkylthio groups having a total of 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, such as a methylthio group, an ethylthio group, a carbamoylmethylthio group, and a t-butylthio group.

[0038] The carbamoylamino group may have an aliphatic group, an aryl group, a heterocyclic group, etc. Examples of the carbamoylamino group include a carbamoylamino group, an alkylcarbamoylamino group having a total of 2 to 9 carbon atoms, a dialkylcarbamoylamino group having a total of 3 to 10 carbon atoms, an arylcarbamoylamino group having a total of 7 to 13 carbon atoms, and a heterocyclic carbamoylamino group having a total of 3 to 12 carbon atoms, preferably a carbamoylamino group, an alkylcarbamoylamino group having a total of 2 to 7 carbon atoms, a dialkylcarbamoylamino group having a total of 3 to 6 carbon atoms, an arylcarbamoylamino group having a total of 7 to 11 carbon atoms, and a heterocyclic carbamoylamino group having a total of 3 to 10 carbon atoms, such as a carbamoylamino group, a methylcarbamoylamino group, an N,N-dimethylcarbamoylamino group, a phenylcarbamoylamino group, and a 4-pyridinecarbamoylamino group.

[0039] In this disclosure, ranges expressed by endpoints include all numbers subsumed within that range (eg, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0040] In this disclosure, the term "at least 1" includes all numbers greater than or equal to 1 (e.g., at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

[0041] Next, the coating composition of the present disclosure will be described in detail.

[0042] The first coating composition of the present disclosure contains a fluororesin, a polymer (I) containing polymerized units (I) based on a monomer represented by general formula (I), and an aqueous medium, and the content of the polymer (I) is 2000 mass ppm or less based on the composition.

[0043] The viscosity of the first coating composition of the present disclosure is preferably 50 to 1000 mPa·s. The viscosity of the first coating composition of the present disclosure is more preferably 100 mPa·s or higher, even more preferably 110 mPa·s or higher, particularly preferably 120 mPa·s or higher, more preferably 900 mPa·s or lower, and even more preferably 750 mPa·s or lower. A coating composition having a viscosity within the above range exhibits excellent aggregation suppression during stirring and also suppresses molding defects such as dripping during application, thereby producing a beautiful coating film. Herein, the viscosity of the coating composition is measured using a Brookfield viscometer with a No. 2 rotor at a liquid temperature of 25°C and 60 rpm.

[0044] The first coating composition of the present disclosure preferably has a stability retention time of 10 minutes or more as measured by a stirring test. Preferred stability retention times are, in order of preference, 10 minutes or more, 12 minutes or more, 15 minutes or more, 20 minutes or more, and 30 minutes or more. Coating compositions having stability retention times within the above ranges are excellent in inhibiting aggregation during stirring. The upper limit of the stability retention time is not particularly limited, but is usually 120 minutes or less. In this specification, the stability retention time is measured by the stirring test described in the Examples.

[0045] The first coating composition of the present disclosure preferably further contains a nonionic surfactant. By including a nonionic surfactant, the coating composition has excellent agglomeration suppression properties during stirring, and molding defects such as dripping during application are suppressed. Excellent agglomeration suppression properties during stirring make it difficult for aggregates to adhere to the resulting coating film, making it easy to obtain a coating film with excellent film thickness uniformity. Furthermore, excellent agglomeration suppression properties during stirring can suppress large aggregates from adhering to the inside of the narrow nozzle or the tip of the nozzle when spray coating, allowing for highly efficient spray coating.

[0046] The first coating composition of the present disclosure preferably further contains an anionic hydrocarbon surfactant, which provides the coating composition with excellent aggregation suppression properties during stirring and suppresses molding defects such as dripping during application.

[0047] A second coating composition of the present disclosure is a coating composition containing a fluororesin and an aqueous medium, and has a stability retention time of 10 minutes or more as measured by a stirring test, and a viscosity of 50 mPa·s or more and 1000 mPa·s or less.

[0048] The second coating composition of the present disclosure is excellent in inhibiting aggregation during stirring and inhibiting molding defects such as dripping during application, making it possible to produce a beautiful coating film. Furthermore, even when the coating composition contains a relatively large amount of fluororesin, the second coating composition of the present disclosure is excellent in inhibiting aggregation during stirring and inhibiting molding defects such as dripping during application, making it possible to produce a beautiful coating film with high efficiency.

[0049] The preferred stability retention times of the second coating composition of the present disclosure are, in order of preference, 12 minutes or more, 15 minutes or more, 20 minutes or more, and 30 minutes or more. A coating composition having a stability retention time within the above range has even better aggregation suppression properties during stirring. The upper limit of the stability retention time is not particularly limited, but is usually 120 minutes or less.

[0050] The second coating composition of the present disclosure has a viscosity of 50 to 1000 mPa·s. The viscosity of the second coating composition of the present disclosure is preferably 100 mPa·s or more, more preferably 110 mPa·s or more, and even more preferably 120 mPa·s or more, and is preferably 900 mPa·s or less, and more preferably 750 mPa·s or less. By having a viscosity within the above range, the coating composition has even better aggregation suppression properties during stirring, and molding defects such as dripping during application are further suppressed.

[0051] The second coating composition of the present disclosure preferably further contains a polymer (I) containing polymerized units (I) based on a monomer represented by general formula (I). By containing the polymer (I), the aggregation suppression properties of the coating composition during stirring can be further improved.

[0052] The second coating composition of the present disclosure preferably further contains a nonionic surfactant, which provides the coating composition with even better suppression of aggregation during stirring and further suppresses molding defects such as dripping during application.

[0053] The second coating composition of the present disclosure preferably further contains an anionic hydrocarbon surfactant, which provides the coating composition with even better suppression of aggregation during stirring and further suppresses molding defects such as dripping during application.

[0054] A third coating composition of the present disclosure contains a fluororesin, a nonionic surfactant, an anionic hydrocarbon surfactant, and an aqueous medium, and is substantially free of a fluorine-containing compound having a hydrophilic group.

[0055] There is a need for a coating composition that is substantially free of fluorine-containing compounds having hydrophilic groups and that has excellent aggregation-inhibiting properties during stirring. The third composition of the present disclosure is substantially free of fluorine-containing compounds having hydrophilic groups, but contains a nonionic surfactant and an anionic hydrocarbon surfactant, and therefore has excellent aggregation-inhibiting properties during stirring.

[0056] The third coating composition of the present disclosure preferably further contains a polymer (I) containing polymerized units (I) based on a monomer represented by general formula (I). By containing the polymer (I), the aggregation suppression properties of the coating composition during stirring can be further improved.

[0057] The third coating composition of the present disclosure has a suitable stability retention time similar to that of the first coating composition of the present disclosure, and a suitable viscosity similar to that of the first coating composition of the present disclosure.

[0058] The coating composition of the present disclosure preferably has a solids concentration of 20 to 50% by mass, more preferably 22% by mass or more, even more preferably 30% by mass or more, more preferably 48% by mass or less, and even more preferably 45% by mass or less. When the solids concentration is within the above range, a coating film having even better adhesion to the substrate and even better non-stick properties can be formed. In the present disclosure, the solids concentration of the coating composition is the concentration of the residue at 380°C, and specifically, can be measured by the method described in the examples.

[0059] The coating composition of the present disclosure may have a viscosity of 150 mPa·s or more and 500 mPa·s or less, from the viewpoint of being able to improve film-forming properties when the solid content concentration of the coating composition is high.

[0060] The configuration of the coating composition of the present disclosure will be described in more detail below.

[0061] <Fluororesin> The coating composition of the present disclosure (in this disclosure, the first coating composition, second coating composition, and third coating composition of the present disclosure may be referred to as the "coating composition of the present disclosure") contains a fluororesin.

[0062] The fluororesin is not particularly limited as long as it contains fluorine atoms, and examples thereof include polytetrafluoroethylene (PTFE) and fluororesins other than PTFE.

[0063] As the fluororesin other than PTFE, for example, tetrafluoroethylene (TFE) / hexafluoropropylene (HFP) copolymer (FEP), TFE / perfluoro(alkyl vinyl ether) (PAVE) copolymer (PFA), TFE / perfluoroallyl ether copolymer, ethylene / TFE copolymer (ETFE), ethylene / chlorotrifluoroethylene (CTFE) copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), ethylene / TFE / HFP copolymer (EFEP), polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) copolymer, polyvinyl fluoride (PVF) etc. can be enumerated.The fluororesin can be used alone or in combination of two or more kinds.

[0064] In the coating composition of the present disclosure, the fluororesin is preferably at least one selected from PTFE, FEP, PFA, ETFE, and ECTFE, more preferably at least one selected from PTFE, FEP, and PFA, and even more preferably one containing PTFE.

[0065] A preferred embodiment of PTFE as the fluororesin will be described later.

[0066] In one embodiment of the coating composition of the present disclosure, the fluororesin contains at least PTFE. The coating composition of the present disclosure may contain only PTFE as the fluororesin, or may contain PTFE and a fluororesin other than PTFE as the fluororesin. For example, the coating composition of the present disclosure may contain PTFE and at least one selected from the group consisting of FEP and PFA as the fluororesin.

[0067] When the coating composition of the present disclosure contains PTFE, the PTFE content in the coating composition of the present disclosure is preferably 10.0% by mass or more and 52.0% by mass or less. The preferred lower limit of the PTFE content is, in order of preference, 15.0% by mass or more, 16.0% by mass or more, 18.0% by mass or more, and 20.0% by mass or more. The upper limit of the PTFE content is more preferably 50.0% by mass or less, and even more preferably 48.0% by mass or less.

[0068] In one embodiment of the coating composition of the present disclosure, the PTFE content in the coating composition is 30.0% by mass or more and 52.0% by mass or less. In this case, the PTFE content in the coating composition is more preferably 32.0% by mass or more, even more preferably 35.0% by mass or more, more preferably 50.0% by mass or less, and even more preferably 48.0% by mass or less. By having the PTFE content in the coating composition within the above range, a coating film with a high PTFE content can be easily obtained with high efficiency.

[0069] In the coating composition of the present disclosure, the amount of PTFE present in the fluororesin is preferably 55.0% by mass or more, more preferably 60.0% by mass or more, and even more preferably 65.0% by mass or more, and may be 100.0% by mass or less.

[0070] In one embodiment of the coating composition of the present disclosure, the content of PTFE in the coating composition is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and preferably 100% by mass or less, relative to the mass of the fluororesin in the coating composition. Furthermore, the coating composition of the present disclosure may contain only PTFE as the fluororesin.

[0071] In one embodiment of the first coating composition of the present disclosure, the amount of PTFE present in the fluororesin is 90.0 mass% or more. In this case, the amount of PTFE present in the fluororesin is more preferably 95.0 mass% or more, even more preferably 96.0 mass% or more, and may be 100.0 mass%. By having the amount of PTFE present in the fluororesin within the above range, a coating film with a high PTFE content can be easily obtained with high efficiency.

[0072] Although the FEP is not particularly limited, a copolymer in which the molar ratio of TFE units to HFP units (TFE units / HFP units) is 70 / 30 or more and less than 99 / 1 is preferred. A more preferred molar ratio is 70 / 30 or more and 98.9 / 1.1 or less, and an even more preferred molar ratio is 80 / 20 or more and 98.9 / 1.1 or less. If the TFE units are too few, mechanical properties tend to decrease, while if the TFE units are too many, the melting point tends to become too high and film-forming properties tend to decrease. It is also preferred that the FEP is a copolymer in which the monomer units derived from monomers copolymerizable with TFE and HFP are 0.1 to 10 mol %, and the total of TFE units and HFP units is 90 to 99.9 mol %. Examples of monomers copolymerizable with TFE and HFP include PAVE and alkyl perfluorovinyl ether derivatives.

[0073] The melting point of FEP is preferably 150 to less than 322°C, more preferably 200 to 320°C, even more preferably 200 to 300°C, and particularly preferably 215 to 280°C.

[0074] The thermal decomposition starting temperature of FEP is preferably 360° C. or higher, more preferably 380° C. or higher, and even more preferably 390° C. or higher.

[0075] When the coating composition of the present disclosure contains FEP, the content of FEP in the coating composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and preferably 70.0% by mass or less, more preferably 60.0% by mass or less, even more preferably 52.0% by mass or less, and particularly preferably 50.0% by mass or less. In one embodiment, the content of FEP is preferably 0.1 to 20.0% by mass, more preferably 0.5 to 15.0% by mass, and even more preferably 1.0 to 50.0% by mass.

[0076] In the present disclosure, the thermal decomposition onset temperature is the temperature at which a 10 mg sample loses 1 mass % when heated from room temperature at a heating rate of 10°C / min using a differential thermal / thermogravimetric analyzer [TG-DTA] (trade name: TG / DTA6200, manufactured by Seiko Electronics Co., Ltd.).

[0077] The PFA is not particularly limited, but a copolymer in which the molar ratio of TFE units to PAVE units (TFE units / PAVE units) is 70 / 30 or more and less than 99 / 1 is preferred. A more preferred molar ratio is 70 / 30 or more and 98.9 / 1.1 or less, and an even more preferred molar ratio is 80 / 20 or more and 98.9 / 1.1 or less. If the TFE units are too few, the mechanical properties tend to decrease, while if the TFE units are too many, the melting point tends to become too high and the film-forming properties tend to decrease. It is also preferred that the PFA is a copolymer in which the monomer units derived from monomers copolymerizable with TFE and PAVE are 0.1 to 10 mol %, and the total of the TFE units and PAVE units is 90 to 99.9 mol %. Examples of monomers copolymerizable with TFE and PAVE include HFP, CZ ３ Z ４ =CZ ５ (CF ２ ) ｎ Z ６ (In the formula, Z ３ , Z ４ and Z ５ are the same or different and represent a hydrogen atom or a fluorine atom; Z ６ represents a hydrogen atom, a fluorine atom, or a chlorine atom, and n represents an integer of 2 to 10. ２ =CF-OCH ２ -Rf ７ (wherein, Rf ７ represents a perfluoroalkyl group having 1 to 5 carbon atoms.

[0078] The melting point of PFA is preferably 180 to less than 322°C, more preferably 230 to 320°C, and even more preferably 280 to 320°C.

[0079] The thermal decomposition starting temperature of PFA is preferably 380° C. or higher, more preferably 400° C. or higher, and even more preferably 410° C. or higher.

[0080] When the coating composition of the present disclosure contains PFA, the content of PFA in the coating composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, preferably 70.0% by mass or less, more preferably 60.0% by mass or less, even more preferably 52.0% by mass or less, and particularly preferably 50.0% by mass or less. In one embodiment, the content of PFA is preferably 0.1 to 20.0% by mass, more preferably 0.5 to 15.0% by mass, and even more preferably 1.0 to 10.0% by mass.

[0081] The content of each monomer unit of a fluororesin (PTFE and fluororesins other than PTFE) can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis depending on the type of monomer.

[0082] In the coating composition of the present disclosure, the content of the fluororesin is preferably 15.0 to 52.0% by mass relative to the coating composition. The content of the fluororesin is more preferably 16% by mass or more, even more preferably 18.0% by mass or more, particularly preferably 20.0% by mass or more, most preferably 30.0% by mass or more, more preferably 50.0% by mass or less, and even more preferably 48.0% by mass or less. The content of the fluororesin in the coating composition can be determined as the solids concentration of the coating composition.

[0083] In one embodiment of the coating composition of the present disclosure, at least FEP is contained as the fluororesin. The coating composition of the present disclosure may contain only FEP as the fluororesin, or may contain FEP and a fluororesin other than FEP as the fluororesin.

[0084] In one embodiment of the coating composition of the present disclosure, at least PFA is contained as the fluororesin. The coating composition of the present disclosure may contain only PFA as the fluororesin, or may contain PFA and a fluororesin other than PFA as the fluororesin.

[0085] <Polytetrafluoroethylene (PTFE)> In one embodiment of the coating composition of the present disclosure, polytetrafluoroethylene (PTFE) is contained as the fluororesin.

[0086] Polytetrafluoroethylene (PTFE) generally has extensibility, fibrillation properties, and non-melt fabrication properties. Non-melt fabrication properties mean that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point in accordance with ASTM D 1238 and D 2116, i.e., the PTFE does not flow easily even in the melting temperature range.

[0087] The PTFE may be a tetrafluoroethylene (TFE) homopolymer, or may be a modified PTFE containing TFE units and modified monomer units.

[0088] The modifying monomer is not particularly limited as long as it is copolymerizable with TFE, and examples thereof include fluoromonomers and non-fluoromonomers.

[0089] The non-fluoromonomer is not particularly limited and may be a monomer represented by the general formula: ２ =CR Ｑ１ -LR Ｑ２ (In the formula, R Ｑ１ represents a hydrogen atom or an alkyl group. L represents a single bond, -CO-O-*, -O-CO-* or -O-. * represents R Ｑ２ represents the bonding position with Ｑ２ represents a hydrogen atom, an alkyl group or a nitrile group.

[0090] Examples of non-fluoromonomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, vinyl methacrylate, vinyl acetate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, ethyl vinyl ether, cyclohexyl vinyl ether, etc. Of these, butyl methacrylate, vinyl acetate, and acrylic acid are preferred as non-fluoromonomers.

[0091] Examples of fluoromonomers include perfluoroolefins such as hexafluoropropylene (HFP); chlorofluoroolefins such as chlorotrifluoroethylene (CTFE); hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride (VDF); fluoro(alkyl vinyl ethers); (perfluoroalkyl)ethylenes; and perfluoroallyl ethers.

[0092] The modifying monomer used may be one type or a plurality of types.

[0093] The fluoro(alkyl vinyl ether) is not particularly limited, and examples thereof include fluoro(alkyl vinyl ethers) represented by the general formula (A): CF ２ ═CF-ORf (A) (wherein Rf represents a perfluoroorganic group). In the present disclosure, the term "perfluoroorganic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. The perfluoroorganic group may have an ether oxygen.

[0094] An example of the fluoro(alkyl vinyl ether) is perfluoro(alkyl vinyl ether) (PAVE) represented by the general formula (A), where Rf is a perfluoroalkyl group having 1 to 10 carbon atoms. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5.

[0095] Examples of the perfluoroalkyl group in PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

[0096] Further, the fluoro(alkyl vinyl ether) may be a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms in the general formula (A), ... or a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms in the general formula (A)

[0097]

[0098] (wherein m represents 0 or an integer of 1 to 4), and Rf is a group represented by the following formula:

[0099] CF ３ CF ２ CF ２ -(O-CF(CF ３ )-CF ２ ) ｎ - (wherein n represents an integer of 1 to 4).

[0100] Hydrogen-containing fluoroolefins include CH ２ =CF ２ , CFH=CH ２ , CFH=CF ２ , C.H. ２ =CFCF ３ , C.H. ２ = CHCF ３ , CHF=CHCF ３ (E form), CHF=CHCF ３ (Z-isomer), etc.

[0101] The fluoro(alkyl vinyl ether) is preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE), and more preferably PMVE.

[0102] The (perfluoroalkyl)ethylene (PFAE) is not particularly limited, and examples thereof include (perfluorobutyl)ethylene (PFBE), (perfluorohexyl)ethylene, and (perfluorooctyl)ethylene.

[0103] Examples of perfluoroallyl ethers include those represented by the general formula: CF ２ =CF-CF ２ Examples of the fluoromonomer include those represented by —ORf (wherein Rf represents a perfluoroorganic group).

[0104] Rf in the above general formula is the same as Rf in general formula (A). Rf is preferably a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. Examples of perfluoroallyl ethers include CF ２ =CF-CF ２ -O-CF ３ , C.F. ２ =CF-CF ２ -O-C ２ F ５ , C.F. ２ =CF-CF ２ -O-C ３ F ７ , and CF ２ =CF-CF ２ -O-C ４ F ９ At least one selected from the group consisting of CF ２ =CF-CF ２ -O-C ２ F ５ , C.F. ２ =CF-CF ２ -O-C ３ F ７ , and CF ２ =CF-CF ２ -O-C ４ F ９ More preferably, at least one selected from the group consisting of CF ２ =CF-CF ２ -O-CF ２ CF ２ CF ３ is more preferable.

[0105] The content of the modified monomer unit in the modified PTFE is preferably in the range of 0.00001 to 1.0% by mass relative to all polymerized units. The lower limit is preferably 0.0001% by mass, more preferably 0.001% by mass, and even more preferably 0.005% by mass. The upper limit of the content of the modified monomer unit is, in order of preference, 0.90% by mass, 0.50% by mass, 0.30% by mass, 0.20% by mass, 0.15% by mass, 0.10% by mass, and 0.05% by mass. In the present disclosure, the modified monomer unit refers to a portion of the molecular structure of the modified PTFE that is derived from the modified monomer.

[0106] Preferred examples of the modifying monomer include comonomer (3) having a monomer reactivity ratio of 0.1 to 8. The presence of comonomer (3) makes it possible to obtain PTFE particles with a small particle size, and to obtain a coating composition that is excellent in inhibiting aggregation during stirring.

[0107] Here, the monomer reactivity ratio in copolymerization with TFE is the value obtained by dividing the rate constant of the reaction of the growing radical with TFE when the growing radical is less than the repeating unit based on TFE by the rate constant of the reaction of the growing radical with comonomer.The lower this value, the higher the reactivity of the comonomer with TFE.The monomer reactivity ratio can be calculated by copolymerizing TFE with comonomer, determining the composition in the produced polymer immediately after the start, and using the Feynman-Ross equation.

[0108] The copolymerization was carried out in a 6.0L stainless steel autoclave using 3600g of deionized and degassed water, 1000 mass ppm of ammonium perfluorooctanoate relative to the water, and 100g of paraffin wax at a pressure of 0.78 MPaG and a temperature of 70°C. 0.05g, 0.1g, 0.2g, 0.5g, and 1.0g of comonomer were added to the reactor, respectively, and 0.072g of ammonium persulfate (20 mass ppm relative to water) was added. TFE was continuously fed to maintain the polymerization pressure at 0.78 MPaG. When the TFE loading reached 1000g, stirring was stopped and the reactor was depressurized until atmospheric pressure was reached. After cooling, the paraffin wax was separated to obtain an aqueous dispersion containing the resulting polymer. The aqueous dispersion was stirred to coagulate the resulting polymer, and then dried at 150°C. The composition of the resulting polymer is calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis depending on the type of monomer.

[0109] The comonomer (3) having a monomer reactivity ratio of 0.1 to 8 is preferably at least one selected from the group consisting of comonomers represented by formulas (3a) to (3d): CH ２ =CH-Rf １ (3a) (wherein, Rf １ is a perfluoroalkyl group having 1 to 10 carbon atoms.) CF ２ ═CF—O—Rf ２ (3b) (wherein, Rf ２ is a perfluoroalkyl group having 1 to 2 carbon atoms.) CF ２ =CF-O-(CF ２ ) ｎ CF = CF ２ (3c) (Wherein, n is 1 or 2.)

[0110] (In the formula, X ３ and X ４ is F, Cl or a methoxy group, and Y is of formula Y1 or Y2.

[0111] (In formula Y2, Z and Z′ are F or a fluorinated alkyl group having 1 to 3 carbon atoms.)

[0112] The content of the comonomer (3) unit is preferably in the range of 0.00001 to 1.0 mass% relative to the total polymerized units of the modified PTFE. The lower limit is more preferably 0.0001 mass%, even more preferably 0.001 mass%, even more preferably 0.005 mass%, and particularly preferably 0.009 mass%. The upper limit is, in order of preference, 0.90 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.08 mass%, 0.05 mass%, and 0.01 mass%.

[0113] As the modified monomer, since it can obtain the coating composition with small average primary particle diameter of modified polytetrafluoroethylene particles, small aspect ratio of primary particles, and excellent aggregation suppression during stirring, it is preferred to select at least one from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, fluoro(alkyl vinyl ether), (perfluoroalkyl)ethylene, ethylene, and modified monomers having functional groups and hydrophilic groups that can react by radical polymerization.By using the modified monomer, it can obtain the coating composition with smaller average primary particle diameter, small aspect ratio of primary particles, and excellent aggregation suppression during stirring.In addition, it can obtain the coating composition with less uncoagulated polymer.

[0114] The modified monomer preferably includes a modified monomer having a functional group capable of reacting by radical polymerization and a hydrophilic group (hereinafter referred to as "modified monomer (A)").

[0115] By adding the modified monomer (A), it is possible to obtain PTFE particles with a small primary particle size, and to obtain a coating composition with excellent aggregation suppression during stirring. It is also possible to reduce the amount of uncoagulated polymer. Furthermore, it is possible to reduce the aspect ratio of the primary particles.

[0116] The PTFE containing TFE unit and modified monomer (A) unit can be obtained, for example, by polymerizing TFE and modified monomer (A) in aqueous medium.The amount of modified monomer (A) used during polymerization is preferably more than the amount corresponding to 0.1 mass ppm of aqueous medium, more preferably more than 0.5 mass ppm, even more preferably more than 1.0 mass ppm, even more preferably more than 5 mass ppm, particularly preferably more than 10 mass ppm.If the amount of modified monomer (A) used is too small, the average primary particle diameter of the obtained PTFE may not be small.The amount of modified monomer (A) used may be within the above range, and for example, the upper limit can be set to 5000 mass ppm.

[0117] Since the modified monomer (A) is highly water-soluble, even if the coating composition contains unreacted modified monomer (A), the modified monomer (A) can be easily removed from the coating composition by methods such as concentration, coagulation, and washing.

[0118] The hydrophilic group in the modified monomer (A) is, for example, —NH ２ , -PO ３ M, -P(O)(OM) ２ , -OPO ３ M, -OP(O)(OM) ２ , -SO ３ M, -OSO ３ M, -COOM (in each formula, M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ７ are H or organic groups and may be the same or different. Any two of them may be bonded to each other to form a ring.) Among the above hydrophilic groups, -SO ３ M or -COOM is preferred. ７ The organic group in R is preferably an alkyl group. ７ As the group, H or C １－１０ is preferably an organic group represented by the formula: １－４ More preferred are organic groups represented by the formula:１－４ The metal atom is preferably a monovalent or divalent metal atom, such as an alkali metal (Group 1) or an alkaline earth metal (Group 2), and more preferably Na, K, or Li.

[0119] Examples of the "functional group capable of reacting by radical polymerization" in the modifying monomer (A) include groups having an ethylenically unsaturated bond, such as a vinyl group and an allyl group. The group having an ethylenically unsaturated bond is a group represented by the following formula: CX ｅ X ｇ =CX ｆ R- (wherein, X ｅ , X ｆ and X ｇ are each independently F, Cl, H, or CF ３ , C.F. ２ H, C.F.H. ２ , or CH ３ and R is a linking group. The linking group of R can be represented by the formula: ａ Preferably, the linking group is -CH=CH ２ , -CF=CH ２、 -CH=CF ２、 -CF = CF ２ , -CH ２ -CH=CH ２ , -CF ２ -CF=CH ２ , -CF ２ -CF = CF ２ , -(C=O)-CH=CH ２ , -(C=O)-CF=CH ２ , -(C=O)-CH=CF ２ , -(C=O)-CF=CF ２ , -(C=O)-C(CH ３ ) = CH ２ , -(C=O)-C(CF ３ ) = CH ２ , -(C=O)-C(CH ３ ) = CF ２ , -(C=O)-C(CF ３ ) = CF ２ , —O—CH ２ -CH=CH ２ , —O—CF ２ -CF=CH２ , —O—CH ２ -CH=CF ２ , —O—CF ２ -CF = CF ２ Examples of groups having an unsaturated bond include the following.

[0120] Since the modified monomer (A) has functional group that can react by radical polymerization, it is presumed that when used in polymerization, it will react with TFE at the initial stage of polymerization reaction, and will form particles that have hydrophilic groups derived from the modified monomer (A) and have high stability.Therefore, it is considered that when polymerization is carried out in the presence of the modified monomer (A), the number of particles will increase.

[0121] The polymerization may be carried out in the presence of one type of the modifying monomer (A) or in the presence of two or more types thereof.

[0122] In the polymerization, a compound having an unsaturated bond can be used as the modifying monomer (A).

[0123] The modifying monomer (A) is a compound represented by the general formula (4A): CX ｉ X ｋ =CX ｊ R ａ - (CZ １ Z ２ ) ｋ -Y ３ (4A) (wherein, X ｉ , X ｊ and X ｋ are each independently F, Cl, H or CF ３ and Y ３ is a hydrophilic group; R ａ is a linking group; Z １ and Z ２ are each independently H, F or CF ３ and k is 0 or 1. Examples of the hydrophilic group include —NH ２ , -PO ３ M, -P(O)(OM) ２ , -OPO ３ M, -OP(O)(OM) ２ , -SO ３ M, -OSO ３M, -COOM (in each formula, M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ７ are H or organic groups and may be the same or different. Any two of them may be bonded to each other to form a ring.) Among the above hydrophilic groups, -SO ３ M or -COOM is preferred. ７ As the group, H or C １－１０ is preferably an organic group represented by the formula: １－４ More preferred are organic groups represented by the formula: １－４ The alkyl group represented by the formula (I) is more preferred. Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred. By using the modified monomer (4A), it is possible to obtain a coating composition having a smaller average primary particle size and better aggregation suppression properties during stirring. It is also possible to further reduce the aspect ratio of the primary particles.

[0124] The above R ａ is a linking group. In the present disclosure, a "linking group" refers to a divalent linking group. The linking group may be a single bond and preferably contains at least one carbon atom. The number of carbon atoms may be 2 or more, 4 or more, 8 or more, 10 or more, or 20 or more. There is no upper limit, but it may be, for example, 100 or less, or 50 or less. The linking group may have a linear or branched, cyclic or acyclic structure, 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 may optionally 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, but may contain a catenary heteroatom such as oxygen, sulfur, or nitrogen.

[0125] The above R ａis preferably a catenary heteroatom such as oxygen, sulfur, or nitrogen, or a divalent organic group. ａ When R is a divalent organic group, the hydrogen atom bonded to the carbon atom may be replaced with a halogen other than fluorine, such as chlorine, and the group may or may not contain a double bond. ａ may be either linear or branched, and may be either cyclic or acyclic. ａ R may contain functional groups (e.g., esters, ethers, ketones, amines, halides, etc.). ａ R may also be a non-fluorinated divalent organic group, or a partially fluorinated or perfluorinated divalent organic group. ａ Examples of the hydrocarbon group include a hydrocarbon group in which no fluorine atoms are bonded to a carbon atom, a hydrocarbon group in which some of the hydrogen atoms bonded to a carbon atom are substituted with fluorine atoms, a hydrocarbon group in which all of the hydrogen atoms bonded to a carbon atom are substituted with fluorine atoms, -(C=O)-, -(C=O)-O-, or a hydrocarbon group containing an ether bond, which may contain an oxygen atom, a double bond, or a functional group.

[0126] R ａ is preferably -(C=O)-, -(C=O)-O-, or a hydrocarbon group having 1 to 100 carbon atoms which may contain an ether bond and may contain a carbonyl group, and in the hydrocarbon group, some or all of the hydrogen atoms bonded to the carbon atoms may be substituted with fluorine. ａ is preferably —(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 -[(CF ２ ) ｃ -O] ｄ -、-O-[CF ２ CF(CF ３ )O] ａ -(CF ２ ) ｂ -、-(C=O)-、-(C=O)-O-、-(C=O)-(CH ２ ) ａ -、-(C=O)-(CF ２ ) ａ -、-(C=O)-O-(CH ２ ) ａ -、-(C=O)-O-(CF ２ ) ａ -、-(C=O)-[(CH ２ ) ａ -O] ｂ -、-(C=O)-[(CF ２ ) ａ -O] ｂ -、-(C=O)-O[(CH ２ ) ａ -O] ｂ -、-(C=O)-O[(CF ２ ) ａ -O] ｂ -、-(C=O)-O[(CH ２ ) ａ -O] ｂ -(CH ２ ) ｃ -、-(C=O)-O[(CF ２ ) ａ -O] ｂ -(CF ２ ) ｃ -、-(C=O)-(CH ２ )ａ -O-(CH ２ ) ｂ -, -(C=O)-(CF ２ ) ａ -O-(CF ２ ) ｂ -, -(C=O)-O-(CH ２ ) ａ -O-(CH ２ ) ｂ -, -(C=O)-O-(CF ２ ) ａ -O-(CF ２ ) ｂ -, -(C=O)-OC ６ H ４ - and at least one selected from combinations thereof. In the formula, a, b, c, and d are independently at least 1. a, b, c, and d may independently be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limits of a, b, c, and d are, for example, 100.

[0127] R ａ A specific example of a suitable group is —CF ２ —O—, —CF ２ -O-CF ２ -, -CF ２ -O-CH ２ -, -CF ２ -O-CH ２ CF ２ -, -CF ２ -O-CF ２ CF ２ -, -CF ２ -O-CF ２ CH ２ -, -CF ２ -O-CF ２ CF ２ CH 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(CF３ ) CH ２ —, —(C=O)—, —(C=O) —O—, —(C=O)—(CH ２ )—, —(C=O)—(CF ２ )—, —(C=O)—O—(CH ２ )—, —(C=O)—O—(CF ２ )—, —(C=O)—[(CH ２ ) ２ —O] ｎ —, —(C=O)—[(CF ２ ) ２ —O] ｎ —, —(C=O)—O[(CH ２ ) ２ —O] ｎ —, —(C=O)—O[(CF ２ ) ２ —O] ｎ —, —(C=O)—O[(CH ２ ) ２ —O] ｎ —(CH ２ )—, —(C=O)—O[(CF ２ ) ２ —O] ｎ 。—(CF ２ )—, —(C=O)—(CH ２ ) ２ —O—(CH ２ )—, —(C=O)—(CF ２ ) ２ —O—(CF ２ )—, —(C=O)—O—(CH ２ ) ２ —O—(CH ２ )—, —(C=O)—O—(CF ２ ) ２ —O—(CF ２ )—, —(C=O)—O—C ６ H ４ — etc. are included. Among them, the above R ａ is specifically, —CF ２ —O—, —CF ２ —O—CF ２ —, —CF ２ —O—CF ２ CF ２ —, —CF ２ —O—CF(CF[[ID=**96**]] ３ )—, —CF２ -O-CF(CF ３ )CF ２ -, -CF ２ -O-CF(CF ３ )CF ２ -O-, -(C=O)-, -(C=O)-O-, -(C=O)-(CH ２ )-,-(C=O)-O-(CH ２ )-,-(C=O)-O[(CH ２ ) ２ -O] ｎ -, -(C=O)-O[(CH ２ ) ２ -O] ｎ - (CH ２ )-,-(C=O)-(CH ２ ) ２ -O-(CH ２ )-, or -(C=O)-O-C ６ H ４ In the above formula, n is an integer of 1 to 10.

[0128] -R in general formula (4A) ａ - (CZ １ Z ２ ) ｋ - is -CF ２ -O-CF ２ -, -CF ２ -O-CF(CF ３ ) -, -CF ２ -O-C(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 )-、-CF ２ -O-CF(CF ３ )CF ２ -O-C(CF ３ ) ２ -、-(C=O)-、-(C=O)-O-、-(C=O)-(CH ２ )-、-(C=O)-(CF ２ )-、-(C=O)-O-(CH ２ )-、-(C=O)-O-(CF ２ )-、-(C=O)-[(CH ２ ) ２ -O] ｎ -(CH ２ )-、-(C=O)-[(CF ２ ) ２ -O] ｎ -(CF ２)-、-(C=O)-[(CH ２ ) ２ -O] ｎ -(CH ２ )-(CH ２ )-、-(C=O)-[(CF ２ ) ２ -O] ｎ -(CF ２ )-(CF ２ )-、-(C=O)-O[(CH ２ ) ２ -O] ｎ -(CF ２ )-、-(C=O)-O[(CH ２ ) ２ -O] ｎ -(CH ２ )-(CH ２ )-、-(C=O)-O[(CF ２ ) ２ -O] ｎ -(CF ２ )-、-(C=O)-O[(CF ２ ) ２ -O] ｎ -(CF ２ )-(CF ２ )-、-(C=O)-(CH ２ ) ２ -O-(CH ２ )-(CH ２ )-、-(C=O)-(CF ２ ) ２ -O-(CF ２ )-(CF ２ )-、-(C=O)-O-(CH ２ ) ２ -O-(CH ２ )-(CH ２ )-、-(C=O)-O-(CF ２ ) ２ -O-(CF ２ )-(CF ２ )-、-(C=O)-O-(CH ２ ) ２ -O-(CH ２ )-C(CF ３ ) ２ -、-(C=O)-O-(CF ２ ) ２ -O-(CF ２ )-C(CF３ ) ２ - or -(C=O)-O-C ６ H ４ -C(CF ３ ) ２ - is preferred, and -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 ) -, -CF ２ -O-CF(CF ３ )CF ２ -O-CF(CF ３ )-, -(C=O)-, -(C=O)-O-(CH ２ )-,-(C=O)-O-(CH ２ )-(CH ２ )-,-(C=O)-O[(CH ２ ) ２ -O] ｎ - (CH ２ )-(CH ２ )-,-(C=O)-O-(CH ２ ) ２ -O-(CH ２ )-C(CF ３ ) ２ - or -(C=O)-O-C ６ H ４ -C(CF ３ ) ２ In the above formula, n is an integer of 1 to 10.

[0129] Specific examples of the compound represented by general formula (4A) include: (In the formula, X ｊ and Y ３ is the same as above. n is an integer of 1 to 10.

[0130] R ａ As the general formula (r1): -(C=O) ｈ -(O) ｉ -CF ２ -O-(CX ６ ２ ) ｅ -{O-CF(CF ３ ) ｆ -(O) ｇ - (r1) (wherein, X ６ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1), and a divalent group represented by the general formula (r2): -(C=O) ｈ -(O) ｉ -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ - (r2) (wherein, X ７ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, and i is 0 or 1.) is also preferred.

[0131] -R in general formula (4A) ａ - (CZ １ Z ２ ) ｋ - also includes the general formula (t1): -(C=O) ｈ -(O) ｉ -CF ２ -O-(CX ６ ２ ) ｅ -{O-CF(CF ３ ) ｆ -(O) ｇ -CZ １ Z ２ - (t1) (wherein, X ６ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, and Z １ and Z２ are each independently F or CF ３ In formula (t1), a divalent group represented by １ and Z ２ is one F and the other CF ３ In addition, in the general formula (4A), -R ａ - (CZ １ Z ２ ) ｋ - is a group represented by the general formula (t2): -(C=O) ｈ -(O) ｉ -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ -CZ １ Z ２ - (t2) (wherein, X ７ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, g is 0 or 1, h is 0 or 1, i is 0 or 1, and Z １ and Z ２ are each independently F or CF ３ In formula (t2), a divalent group represented by １ and Z ２ is one F and the other CF ３ It is more preferable that:

[0132] The compound represented by the general formula (4A) is a compound having a hydrophilic group (Y ３ ) except for the above, it is also preferable that the compound has a C—F bond and does not have a C—H bond. ｉ , X ｊ , and X ｋ All of the are F and R ａ is preferably a perfluoroalkylene group having one or more carbon atoms, and the perfluoroalkylene group may be either linear or branched, may be cyclic or acyclic, and may contain at least one catenary heteroatom. The number of carbon atoms in the perfluoroalkylene group may be 2 to 20, or may be 4 to 18.

[0133] The compound represented by the general formula (4A) may be partially fluorinated. That is, the compound represented by the general formula (4A) may have a hydrophilic group (Y ３ ), it is also preferred that the alkyl group has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0134] The compound represented by general formula (4A) is also preferably a compound represented by the following formula (4A-a): CF ２ ═CF—O—Rf ０ -Y ３ (4A-a) (wherein, Y ３ is a hydrophilic group, and Rf ０ is a perfluorinated divalent linking group which may be linear or branched, cyclic or acyclic in structure, saturated or unsaturated, substituted or unsubstituted, and which optionally contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen.

[0135] The compound represented by general formula (4A) is also preferably a compound represented by the following formula (4A-b): CH ２ =CH-O-Rf ０ -Y ３ (4A-b) (wherein, Y ３ is a hydrophilic group, and Rf ０ is a perfluorinated divalent linking group defined by formula (4A-a).

[0136] In general formula (4A), Y ３ Ha-OSO ３ One of the preferred embodiments is Y. ３ Ga-OSO ３ When M is a compound represented by general formula (4A), CF ２ =CF(OCF ２ CF ２ CH ２ OSO ３ M), CH ２ =CH((CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(O(CF ２ )４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OSO ３ M), CH ２ =CH((CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OSO ３ M), CH ２ =CH(CF ２ CF ２ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OSO ３ M), CH ２ =CH(CF ２ CF ２ CH ２ OSO ３ In the above formula, M is the same as above.

[0137] In general formula (4A), Y ３ Ha-SO ３ M is also a preferred embodiment. ３ Ga-SO ３ When M is a polymerized unit based on the compound represented by general formula (4A), CF ２ =CF(OCF２ CF ２ SO ３ M), CF ２ =CF(O(CF ２ ) ４ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ SO ３ M), CH ２ =CH(CF ２ CF ２ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ CF ２ SO ３ M), CH ２ =CH((CF ２ ) ４ SO ３ M), CH ２ =CH(CF ２ CF ２ SO ３ M), CH ２ =CH((CF ２ ) ３ SO ３ In the above formula, M is the same as above.

[0138] In general formula (4A), Y ３ It is also a preferred embodiment that Y is -COOM. ３ is -COOM, the compound represented by general formula (4A) is CF ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(OCF ２ CF ２ CF ２ COOM), C.F. ２ =CF(O(CF ２ )５ COOM), CF ２ =CF(OCF ２ CF(CF ３ ), COOM), CF ２ =CF(OCF ２ CF(CF ３ ), O(CF ２ ) ｎ COOM) (n is greater than 1), CH ２ =CH(CF ２ CF ２ COOM), CH ２ =CH((CF ２ ) ４ COOM), CH ２ =CH(CF ２ CF ２ COOM), CH ２ =CH((CF ２ ) ３ COOM), CF ２ =CF(OCF ２ CF ２ SO ２ NR'CH ２ COOM), CF ２ =CF(O(CF ２ ) ４ SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ ), SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ ), OCF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH(CF ２ CF ２ SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ ), OCF ２ CF ２ CF ２ CF ２ SO２ NR'CH ２ COOM), CH ２ =CH((CF ２ ) ４ SO ２ NR'CH ２ COOM), CH ２ =CH(CF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH((CF ２ ) ３ SO ２ NR'CH ２ In the above formula, R' is H or C １－４ is an alkyl group, and M is the same as above.

[0139] In general formula (4A), Y ３ Ha-OPO ３ M or -OP(O)(OM) ２ It is also a preferred embodiment that ３ Ga-OPO ３ M or -OP(O)(OM) ２ In this case, the compound represented by general formula (4A) is CF ２ =CF(OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(O(CF ２ ) ４ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF ２ SO２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(CF ２ CF ２ CH ２ OP (O) (OM) ２ , C.H. ２ =CH((CF ２ ) ４ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(CF ２ CF ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH((CF ２ ) ３ CH ２ OP (O) (OM) ２ In the above formula, M is the same as above.

[0140] In general formula (4A), Y ３ Ha-PO ３ M or -P(O)(OM) ２ It is also a preferred embodiment that ３ Ga-PO ３ M or -OP(O)(OM) ２ In this case, the compound represented by general formula (4A) is CF ２ =CF(OCF ２ CF ２ P(O)(OM) ２ ), CF ２ =CF(O(CF ２ ) ４ P(O)(OM) ２ ), CF ２ =CF(OCF２ CF (CF ３ ) P (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH(CF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH((CF ２ ) ４ P(O)(OM) ２ ), C.H. ２ =CH(CF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH((CF ２ ) ３ P(O)(OM) ２ ) and the like, in which M is the same as above.

[0141] The compound represented by general formula (4A) includes a compound represented by general formula (5A): CX ２ =CY(-CZ ２ -O-Rf-Y ３ ) (5A) (In the formula, X is the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and is -H, -F, an alkyl group or a fluorine-containing alkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is the same as above.), a compound represented by general formula (6A): CX ２ =CY(-O-Rf-Y ３ (6A) (wherein X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is the same as above.) and a compound represented by general formula (7A): CX２ =CY(-Rf-Y ３ (7A) (wherein X may be the same or different and is -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. Y ３ is the same as above.) The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and contains an ether bond between carbon atoms.

[0142] In general formula (5A), X is -H or -F. Both Xs may be -F, or at least one X may be -H. For example, one X may be -F and the other may be -H, or both Xs may be -H.

[0143] In general formula (5A), Y is -H, -F, an alkyl group or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. Y may be -H, -F or -CF ３ is preferred, and —F is more preferred.

[0144] In general formula (5A), Z's may be the same or different and are -H, -F, an alkyl group, or a fluoroalkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The Z's may be -H, -F, or -CF ３ is preferred, and —F is more preferred.

[0145] In general formula (5A), it is preferable that at least one of X, Y, and Z contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0146] In general formula (5A), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. The number of carbon atoms in the fluorine-containing alkylene group is preferably 2 or more. Also, the number of carbon atoms is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. Examples of the fluorine-containing alkylene group include -CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２ CH ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２ The fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0147] The number of carbon atoms of the fluorine-containing alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms of the fluorine-containing alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, and even more preferably 12 or less. Examples of the fluorine-containing alkylene group having an ether bond include those represented by the following formula: (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ ; p1+q1+r1 is an integer of 1 to 10; s1 is 0 or 1; t1 is an integer of 0 to 5). Specific examples of the fluorine-containing alkylene group having an ether bond include -CF(CF ３ )CF ２ -O-CF(CF ３ )-,-(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ )-(wherein n is an integer from 1 to 10), -CF(CF ３ )CF ２ -O-CF(CF ３ ) CH ２ -, -(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ ) CH ２ - (wherein n is an integer of 1 to 10), -CH ２ CF ２ CF ２ O-CH ２ CF ２ CH ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CH ２ -, -CF ２ CF ２ O-CF ２ -, -CF２ CF ２ O-CF ２ CH ２ The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0148] In general formula (5A), Y ３ is -COOM, -SO ３ M or -OSO ３ M (M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ７ are H or organic groups, and may be the same or different. Any two of them may be bonded to each other to form a ring. ７ The organic group in R is preferably an alkyl group. ７ As the group, H or C １－１０ is preferably an organic group represented by the formula: １－４ More preferred are organic groups represented by the formula: １－４ The metal atom may be an alkali metal (Group 1) or an alkaline earth metal (Group 2), and preferably Na, K, or Li. The M may be —H, a metal atom, or —NR ７ ４ is preferred, and —H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or —NR ７ ４ is more preferred, and —H, —Na, —K, —Li or —NH ４ is more preferred, and —Na, —K or —NH ４ is even more preferred, and —Na or —NH ４ is particularly preferred, and —NH ４ The most preferred is the above Y ３ As the group, -COOM or -SO ３ M is preferred, and —COOM is more preferred.

[0149] The compound represented by general formula (5A) is preferably a compound (5a) represented by general formula (5a). ２ =CF(-CF２ -O-Rf-Y ３ ) (5a) (wherein Rf and Y ３ is the same as above.)

[0150] Specific examples of the compound represented by general formula (5a) include compounds represented by the following formula:

[0151]

[0152] (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 are an integer of 0 to 10; s1 is 0 or 1; t1 is an integer of 0 to 5; Y ３ is the same as above. However, Z ３ and Z ４ are both H, then p1+q1+r1+s1 is not 0). More specifically, compounds represented by the following formula:

[0153]

[0154] Among them,

[0155]

[0156] It is preferable that:

[0157] The compound represented by general formula (5a) includes compounds represented by formula (5a) ３ is preferably -COOM, and in particular CH ２ =CFCF ２ OCF (CF ３ ) COOM, and CH ２ =CFCF ２ OCF (CF ３ )CF ２ OCF (CF ３ )COOM (wherein M is as defined above), and CH ２ =CFCF ２ OCF (CF ３ ) COOM is more preferred.

[0158] The compound represented by general formula (5A) is preferably a compound (5b) represented by general formula (5b). ２ ２ =CFCF ２ -O-(CF(CF ３ )CF ２ O) ｎ５ -CF (CF ３ )-Y ３ (5b) (where each X ２ are the same and represent F or H. n5 represents 0 or an integer of 1 to 10, Y ３ is the same as the above definition.)

[0159] In the general formula (5b), n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, from the viewpoint of the aggregation suppression properties of the resulting coating composition during stirring. ３ is preferably -COOM in that it provides adequate water solubility and inhibits aggregation during stirring of the coating composition, and the above M is preferably H or NH in that it is less likely to remain as an impurity and improves the heat resistance of the resulting coating film. ４ It is preferable that:

[0160] Examples of the compound represented by general formula (5c) include CH ２ =CFCF ２ OCF (CF ３ ) COOM, C.H. ２ =CFCF ２ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM (wherein M is as defined above).

[0161] Further, examples of the compound represented by the general formula (5A) include a compound represented by the general formula (5c).

[0162] CF ２ =CFCF ２ -O-Rf-Y ３ (5c) (wherein Rf and Y ３ is the same as above)

[0163] More specifically, etc.

[0164] In general formula (6A), X is -H or -F. Both Xs may be -F, or at least one X may be -H. For example, one X may be -F and the other may be -H, or both Xs may be -H.

[0165] In general formula (6A), Y is -H, -F, an alkyl group or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. Y may be -H, -F or -CF ３ is preferred, and —F is more preferred.

[0166] In general formula (6A), it is preferable that at least one of X and Y contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0167] In general formula (6A), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. The number of carbon atoms in the fluorine-containing alkylene group is preferably 2 or more. The number of carbon atoms in the fluorine-containing alkylene group is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. Examples of the fluorine-containing alkylene group include -CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２ CH ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２The fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0168] In the above general formula (6A), Y ３ is -COOM, -SO ３ M or -OSO ３ M (M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ７ are H or organic groups, and may be the same or different. Any two of them may be bonded to each other to form a ring. ７ The organic group in R is preferably an alkyl group. ７ As the group, H or C １－１０ is preferably an organic group represented by the formula: １－４ More preferred are organic groups represented by the formula: １－４ The metal atom may be an alkali metal (Group 1) or an alkaline earth metal (Group 2), and preferably Na, K, or Li. The M may be —H, a metal atom, or —NR ７ ４ is preferred, and —H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or —NR ７ ４ is more preferred, and —H, —Na, —K, —Li or —NH ４ is more preferred, and —Na, —K or —NH ４ is even more preferred, and —Na or —NH ４ is particularly preferred, and —NH ４ The most preferred is the above Y ３ As the group, -COOM or -SO ３ M is preferred, and —COOM is more preferred.

[0169] The compound represented by general formula (6A) is preferably at least one selected from the group consisting of compounds represented by general formulas (6a), (6b), (6c), (6d), and (6e). ２ =CF-O-(CF ２ ) ｎ１ -Y３ (6a) (wherein n1 represents an integer of 1 to 10, and Y ３ is the same as defined above.) CF ２ =CF-O-(CF ２ C (CF ３ ) F) ｎ２ -Y ３ (6b) (wherein n2 represents an integer of 1 to 5, and Y ３ is the same as the definition above.) CF ２ =CF-O-(CFX １ ) ｎ３ -Y ３ (6c) (wherein, X １ is F or CF ３ n3 represents an integer of 1 to 10; Y ３ is the same as the definition above.) CF ２ =CF-O-(CF ２ CFX １ O) ｎ４ -(CF ２ ) ｎ６ -Y ３ (6d) (wherein n4 represents an integer of 1 to 10, n6 represents an integer of 1 to 3, and Y ３ and X １ is the same as the definition above.) CF ２ =CF-O-(CF ２ CF ２ CFX １ O) ｎ５ -CF ２ CF ２ CF ２ -Y ３ (6e) (wherein n5 represents an integer of 0 to 10, and Y ３ and X １ is the same as the above definition.)

[0170] In the general formula (6a), n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less. ３ is preferably -COOM in that it provides adequate water solubility and excellent inhibition of aggregation during stirring of the coating composition, and M is preferably H or NH in that it is less likely to remain as an impurity and the heat resistance of the resulting coating film is improved. ４ It is preferable that:

[0171] Examples of the compound represented by general formula (6a) include CF ２ =CF-O-CF ２ COOM, C.F. ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(OCF ２ CF ２ CF ２ COOM) (wherein M is as defined above).

[0172] In the general formula (6b), n2 is preferably an integer of 3 or less from the viewpoint of the aggregation suppression property during stirring of the resulting coating composition, and Y ３ is preferably -COOM in that it provides adequate water solubility and excellent aggregation suppression properties during stirring of the coating composition, and M is preferably H or NH in that it is less likely to remain as an impurity and the heat resistance of the resulting coating film is improved. ４ It is preferable that:

[0173] In the general formula (6c), n3 is preferably an integer of 5 or less in terms of water solubility, and Y ３ is preferably -COOM in that it provides suitable water solubility and excellent aggregation suppression properties during stirring of the coating composition, and the above M is preferably H or NH in that it provides good aggregation suppression properties during stirring. ４ It is preferable that:

[0174] In the general formula (6d), the X １ is -CF in terms of the ability to inhibit aggregation during stirring of the coating composition. ３ In terms of water solubility, n4 is preferably an integer of 5 or less, and Y ３ is preferably -COOM in that it provides adequate water solubility and excellent aggregation suppression properties during stirring of the coating composition, and M is preferably H or NH ４ It is preferable that:

[0175] Examples of the compound represented by general formula (6d) include CF ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ COOM (wherein M is H, NH ４ or an alkali metal.

[0176] In the general formula (6e), n5 is preferably an integer of 5 or less in terms of water solubility, and Y ３ is preferably -COOM in that it provides adequate water solubility and excellent aggregation suppression properties during stirring of the coating composition, and M is preferably H or NH ４ It is preferable that:

[0177] Examples of the compound represented by general formula (6e) include CF ２ = CFOCF ２ CF ２ CF ２ COOM (wherein M is H, NH ４ or an alkali metal.

[0178] In general formula (7A), Rf is preferably a fluorine-containing alkylene group having 1 to 40 carbon atoms. In general formula (7A), at least one of X and Y preferably contains a fluorine atom.

[0179] The compound represented by general formula (7A) is represented by general formula (7a): CF ２ =CF-(CF ２ ) ｎ１ -Y ３ (7a) (wherein n1 represents an integer of 1 to 10, and Y ３ is the same as defined above.) and a compound represented by general formula (7b): CF ２ =CF-(CF ２ C (CF ３ ) F) ｎ２ -Y ３ (7b) (wherein n2 represents an integer of 1 to 5, and Y３ is as defined above. ３ is -SO ３ M or -COOM is preferred, where M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. ７ represents H or an organic group.

[0180] In the general formula (7b), n2 is preferably an integer of 3 or less from the viewpoint of the aggregation suppression property during stirring of the resulting coating composition, and Y ３ is preferably -COOM in that it provides adequate water solubility and excellent aggregation suppression properties during stirring of the coating composition, and M is preferably H or NH in that it is less likely to remain as an impurity and the heat resistance of the resulting coating film is improved. ４ It is preferable that:

[0181] The modified monomer preferably contains modified monomer (A), and preferably contains at least one selected from the group consisting of compounds represented by general formula (5c), general formula (6a), general formula (6b), general formula (6c), and general formula (6d), and more preferably contains a compound represented by general formula (5c).

[0182] When the modified monomer comprises the modified monomer (A), the content of the modified monomer (A) unit is preferably in the range of 0.00001 to 1.0 mass% based on the total polymerized units of PTFE.The lower limit is preferably 0.0001 mass%, more preferably 0.001 mass%, even more preferably 0.005 mass%, and particularly preferably 0.009 mass%.The upper limit is, in order of preference, 0.90 mass%, 0.50 mass%, 0.40 mass%, 0.30 mass%, 0.20 mass%, 0.15 mass%, 0.10 mass%, 0.08 mass%, 0.05 mass%, and 0.01 mass%.

[0183] In the present disclosure, the content of each compound unit constituting PTFE can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis depending on the type of compound. In addition, the content of each compound unit constituting PTFE can also be calculated from the amount of modified monomer added used in polymerization.

[0184] The PTFE may have a core-shell structure. Examples of PTFE having a core-shell structure include modified PTFE particles containing a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE. Examples of such modified PTFE include the PTFE described in JP-A-2005-527652.

[0185] The average primary particle diameter of PTFE is preferably 150 nm or more, more preferably 180 nm or more. The larger the average primary particle diameter of PTFE, the more suppressed the increase in paste extrusion pressure when using the powder for paste extrusion molding, resulting in excellent film-forming properties. The upper limit is not particularly limited, but may be 500 nm. From the viewpoint of productivity in the polymerization process, the upper limit is preferably 400 nm, more preferably 350 nm. The average primary particle diameter is determined by diluting an aqueous PTFE dispersion with water to a solids concentration of 0.15% by mass, measuring the transmittance of 550 nm projected light per unit length of the resulting diluted latex, and measuring the number-based average primary particle diameter determined by measuring the unidirectional diameter using a transmission electron microscope photograph, creating a calibration curve, and using this calibration curve to determine the actual transmittance of 550 nm projected light for each sample. The average primary particle diameter can also be measured by dynamic light scattering. The average primary particle size can be measured by preparing an aqueous dispersion adjusted to a solids concentration of about 1.0% by mass, and using dynamic light scattering at 25°C, with a refractive index of the solvent (water) of 1.3328 and a viscosity of the solvent (water) of 0.8878 mPa s, accumulating 70 times. For the dynamic light scattering method, for example, an ELSZ-1000S (manufactured by Otsuka Electronics Co., Ltd.) can be used.

[0186] The aspect ratio of the primary particles of PTFE is preferably less than 2.00, more preferably 1.90 or less, even more preferably 1.80 or less, even more preferably 1.70 or less, particularly preferably 1.60 or less, and particularly preferably 1.50 or less. The aspect ratio is more preferably 1.45 or less, even more preferably 1.40 or less, even more preferably 1.35 or less, particularly preferably 1.30 or less, particularly preferably 1.20 or less, and most preferably 1.10 or less. When measuring in an aqueous dispersion, the aspect ratio is measured by observing the PTFE aqueous dispersion diluted to a solid content concentration of about 1% by mass with a scanning electron microscope (SEM), and randomly selecting 400 or more particles and processing the images, and then calculating the average ratio of the major axis to the minor axis. When measuring the aspect ratio in powder form, the PTFE powder is irradiated with an electron beam, then added to an aqueous fluorosurfactant solution, and re-dispersed by ultrasonic waves to obtain an aqueous PTFE dispersion. The aspect ratio is determined from this aqueous PTFE dispersion in the same manner as in the case of measuring the aspect ratio in aqueous dispersions.

[0187] The standard specific gravity (SSG) of PTFE is preferably 2.280 or less, more preferably 2.210 or less, even more preferably 2.200 or less, even more preferably 2.190 or less, and especially preferably 2.180 or less. Also, it is preferably 2.130 or more. The SSG is measured by the water displacement method according to ASTM D 792 using a sample molded according to ASTM D 4895-89.

[0188] The PTFE preferably has a peak temperature in the range of 333 to 347°C. More preferably, it is 335°C or higher and 345°C or lower. The peak temperature is the temperature corresponding to the maximum value on the heat of fusion curve when PTFE that has not been heated to temperatures above 300°C is heated at a rate of 10°C / min using a differential scanning calorimeter (DSC). The peak temperature can also be specified as the temperature corresponding to the maximum value that appears on a differential thermal (DTA) curve obtained by heating PTFE that has not been heated to temperatures above 300°C at a rate of 10°C / min using a TG / DTA (thermogravimetric / differential thermal analyzer).

[0189] <Polymer (I)> The first coating composition of the present disclosure contains a polymer (I). The second coating composition and the third coating composition of the present disclosure preferably contain a polymer (I). The polymer (I) contains polymerized units (I) based on a monomer represented by general formula (I). The polymer (I) preferably contains two or more polymerized units (I). CX １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more. ２ as F, Cl, H or CF ３ In addition, Z １ and Z ２ As the ３ is preferred.

[0190] In the present disclosure, anionic groups include anionic groups such as sulfate groups, carboxylate groups, and acid groups such as —COOH, —COONH ４ The anionic group includes a functional group that provides an anionic group such as an acid-base group, such as a sulfate group, a carboxylate group, a phosphate group, a phosphonate group, a sulfonate group, or a -C(CF ３ ) ２ OM (wherein M is —H, a metal atom, —NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0191] The polymer (I) may contain only polymerized units (I) based on one type of monomer represented by general formula (I), or may contain polymerized units (I) based on two or more types of monomers represented by general formula (I).

[0192] R is a linking group. In the present disclosure, a "linking group" is an (m+1)-valent linking group, and when m is 1, it refers to 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. There is no upper limit, but it may be, for example, 100 or less, or 50 or less.

[0193] The linking group may be linear or branched, cyclic or acyclic in structure, 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 may optionally 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 but may be a catenary heteroatom such as oxygen, sulfur, or nitrogen.

[0194] m is an integer of 1 or more, preferably 1 or 2, and more preferably 1. When m is an integer of 2 or more, Z １ , Z ２ and A ０ may be the same or different. Next, a preferred structure when m is 1 in general formula (I) will be described.

[0195] R is preferably a catenary heteroatom such as oxygen, sulfur, or nitrogen, or a divalent organic group.

[0196] When R is a divalent organic group, a hydrogen atom bonded to a carbon atom may be replaced with a halogen atom other than fluorine, such as chlorine, and may or may not contain a double bond. R may be either linear or branched, and may be cyclic or acyclic. R may also contain a functional group (e.g., ester, ether, ketone (keto group), amine, halide, etc.).

[0197] R may also be a non-fluorinated divalent organic group, or a partially fluorinated or perfluorinated divalent organic group.

[0198] R may be, for example, a hydrocarbon group in which no fluorine atoms are bonded to the carbon atoms, a hydrocarbon group in which some of the hydrogen atoms bonded to the carbon atoms are substituted with fluorine atoms, or a hydrocarbon group in which all of the hydrogen atoms bonded to the carbon atoms are substituted with fluorine atoms, and these may contain an oxygen atom, a double bond, or a functional group.

[0199] R is preferably a hydrocarbon group having 1 to 100 carbon atoms which may contain an ether bond or a keto group, and in the hydrocarbon group, some or all of the hydrogen atoms bonded to the carbon atoms may be substituted with fluorine.

[0200] R is preferably —(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 - [(CF ２ ) ｃ -O] ｄ -, -O-[CF ２ CF (CF ３ ) O] ａ -(CF ２ ) ｂ -, -[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 at least one selected from combinations thereof. In the formula, a, b, c, and d are independently at least 1. a, b, c, and d may independently be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limits of a, b, c, and d are, for example, 100.

[0201] R is a group represented by the general formula (r1): -CF ２ -O-(CX ６ ２ ) ｅ -{O-CF(CF ３ ) ｆ -(O) ｇ- (r1) (wherein, X ６ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, f is an integer of 0 to 3, and g is 0 or 1), and a divalent group represented by the general formula (r2): -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ - (r2) (wherein, X ７ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, and g is 0 or 1).

[0202] A specific example of a suitable R is —CF ２ —O—, —CF ２ -O-CF ２ -, -CF ２ -O-CH ２ -, -CF ２ -O-CH ２ CF ２ -, -CF ２ -O-CF ２ CF ２ -, -CF ２ -O-CF ２ CH ２ -, -CF ２ -O-CF ２ CF ２ CH 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 -, -CF ２ -O-CF(CF ３ ) CH ２ Among these, R is preferably a perfluoroalkylene group which may contain an oxygen atom, specifically, —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.

[0203] -R-CZ of general formula (I) １ Z ２ - is a group 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) (wherein, X ６ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, and Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group), and in formula (s1), Z １ and Z ２ is F or CF ３ is more preferred, one of which is F and the other is CF ３ It is more preferable that:

[0204] In addition, in the general formula (I), -R-CZ １ Z ２ - is a group represented by the general formula (s2): -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ -CZ １ Z ２ - (s2) (wherein, X ７are each independently H, F or CF ３ where e is an integer of 0 to 3, g is 0 or 1, and Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group), and in formula (s2), Z １ and Z ２ is F or CF ３ is more preferred, one of which is F and the other is CF ３ It is more preferable that:

[0205] -R-CZ of general formula (I) １ Z ２ - is -CF ２ -O-CF ２ -, -CF ２ -O-CF(CF ３ ) -, -CF ２ -O-C(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(CF３ ) 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 -O-C(CF ３ ) ２ - is preferred, and -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 )- is more preferred.

[0206] It is also preferred that the polymer (I) is highly fluorinated. For example, the polymer (I) may contain phosphate group moieties (e.g., CH ２ OP (O) (OM)２ ) and sulfate group moieties (e.g., CH ２ OS (O) ２ anionic groups (A) such as ０ ), it is preferred that 80% or more, 90% or more, 95% or more, or 100% of the C—H bonds in the polymer (I) are substituted with C—F bonds.

[0207] The polymer (I) contains an anionic group (A ０ ) except for the above, it is also preferable that the compound has a C—F bond and does not have a C—H bond. １ , X ２ , and X ３ is preferably F, and R is a perfluoroalkylene group having one or more carbon atoms, and the perfluoroalkylene group may be either linear or branched, may be cyclic or acyclic, and may contain at least one catenary heteroatom. The number of carbon atoms in the perfluoroalkylene group may be 2 to 20, or may be 4 to 18.

[0208] The polymer (I) may be partially fluorinated. That is, the polymer (I) may contain an anionic group (A ０ ), it is also preferred that the alkyl group has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0209] Anionic group (A ０ ) is -SO ３ M, -OSO ３ M, -COOM, -SO ２ NR'CH ２ COOM, -CH ２ OP (O) (OM) ２ , [-CH ２ O] ２ P(O)(OM), -CH ２ CH ２ OP (O) (OM) ２ , [-CH ２ CH ２ O] ２ P(O)(OM), -CH ２ CH ２ OSO ３M, -P(O)(OM) ２ , -SO ２ NR'CH ２ CH ２ OP (O) (OM) ２ , [-SO ２ NR'CH ２ CH ２ O] ２ P(O)(OM), -CH ２ OSO ３ M, -SO ２ NR'CH ２ CH ２ OSO ３ M, or -C(CF ３ ) ２ Among them, -SO ３ M, -OSO ３ M, -COOM, -P(O)(OM) ２ or -C(CF ３ ) ２ -OM is preferred, -COOM and -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM is more preferred, and —SO ３ M, -COOM or -P(O)(OM) ２ is more preferred, and —SO ３ Particularly preferred is M or -COOM, with -COOM being most preferred.

[0210] M is H, a metal atom, or NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0211] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred.

[0212] M is —H, a metal atom, or NR ７ ４ is preferred, and —H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR ７ ４is more preferred, and —H, —Na, —K, —Li or NH ４ is more preferred, and —H, —Na, —K or NH ４ is even more preferred, and —H, —Na or NH ４ is particularly preferred, and —H or —NH ４ is most preferred.

[0213] In the polymer (I), each polymer unit (I) may have a different anionic group or may have the same anionic group.

[0214] The polymer (I) is also preferably a polymer containing polymerized units (Ia) based on a monomer represented by general formula (Ia): CF ２ ═CF—O—Rf ０ -A ０ (Ia) (wherein A ０ is an anionic group, and Rf ０ is a perfluorinated divalent linking group which may be linear or branched, cyclic or acyclic in structure, saturated or unsaturated, substituted or unsubstituted, and which optionally contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen.

[0215] The polymer (I) is also preferably a polymer containing polymerized units (Ib) based on a monomer represented by general formula (Ib). ２ =CH-O-Rf ０ -A ０ (Ib) (wherein, A ０ is an anionic group, and Rf ０ is a perfluorinated divalent linking group as defined in formula Ia.

[0216] In general formula (I), A ０ is a sulfate group. ０ is, for example, —CH ２ OSO ３ M, -CH ２ CH ２ OSO ３ M or -SO ２ NR'CH ２ CH ２ OSO ３M, where R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0217] A ０ is a sulfate group, examples of the monomer represented by general formula (I) include CF ２ =CF(OCF ２ CF ２ CH ２ OSO ３ M), CH ２ =CH((CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(O(CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OSO ３ M), CH ２ =CH((CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OSO ３ M), CH ２ =CH(CF ２ CF ２ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO ２ N (CH ３ ) CH２ CH ２ OSO ３ M), CH ２ =CH(CF ２ CF ２ CF ２ CH ２ OSO ３ In the above formula, M is the same as above.

[0218] In general formula (I), A ０ In one preferred embodiment, A is a sulfonate group. ０ For example, -SO ３ M, where M is the same as above.

[0219] A ０ is a sulfonate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ SO ３ M), CF ２ =CF(O(CF ２ ) ３ SO ３ M), CF ２ =CF(O(CF ２ ) ４ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ SO ３ M), CH ２ =CH(CF ２ CF ２ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ CF ２ SO ３ M), CH ２ =CH((CF ２ )４ SO ３ M), CH ２ =CH(CF ２ CF ２ SO ３ M), CH ２ =CH((CF ２ ) ３ SO ３ In the above formula, M is the same as above.

[0220] In general formula (I), A ０ In one preferred embodiment, A is a carboxylate group. ０ Examples of the group include -COOM and -SO ２ NR'CH ２ COOM, where R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above. ０ is a carboxylate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(O(CF ２ ) ３ COOM), C.F. ２ =CF(O(CF ２ ) ４ COOM), C.F. ２ =CF(O(CF ２ ) ５ COOM), C.F. ２ =CF(OCF ２ CF (CF ３ ) COOM), CF ２ =CF(OCF ２ CF (CF ３ ) O(CF ２ ) ｎ COOM) (n is greater than 1), CH ２ =CH(CF ２ CF ２ COOM), CH ２ =CH((CF ２ ) ４ COOM), CH ２ =CH((CF ２ ) ３ COOM), C.F. ２ =CF(OCF２ CF ２ SO ２ NR'CH ２ COOM), C.F. ２ =CF(O(CF ２ ) ４ SO ２ NR'CH ２ COOM), C.F. ２ =CF(OCF ２ CF (CF ３ ) SO ２ NR'CH ２ COOM), C.F. ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH(CF ２ CF ２ SO ２ NR'CH ２ COOM), C.F. ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH((CF ２ ) ４ SO ２ NR'CH ２ COOM), CH ２ =CH((CF ２ ) ３ SO ２ NR'CH ２ In the above formula, R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0221] In general formula (I), A ０ In one preferred embodiment, A is a phosphate group. ０ Examples of the group include -CH ２ OP (O) (OM) ２ , [-CH ２ O]２ P(O)(OM), -CH ２ CH ２ OP (O) (OM) ２ , [-CH ２ CH ２ O] ２ P(O)(OM), [-SO ２ NR'CH ２ CH ２ O] ２ P(O)(OM) or -SO ２ NR'CH ２ CH ２ OP (O) (OM) ２ wherein R' is an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0222] A ０ is a phosphate, the monomer represented by general formula (I) is CF ２ =CF(OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(O(CF ２ ) ４ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(CF ２ CF ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH((CF ２ ) ４ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH((CF ２ ) ３ CH ２ OP (O) (OM) ２ In the above formula, M is the same as above.

[0223] In general formula (I), A ０ In one preferred embodiment, A is a phosphonate group. ０ is a phosphonate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ P(O)(OM) ２ ), CF ２ =CF(O(CF ２ ) ４ P(O)(OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) P (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH(CF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH((CF ２ ) ４ P(O)(OM) ２ ), C.H. ２ =CH((CF２ ) ３ P(O)(OM) ２ ) wherein M is the same as above.

[0224] The polymer (I) is preferably a polymer (1) containing polymerized units (1) based on a monomer represented by general formula (1): CX ２ =CY(-CZ ２ -O-Rf-A) (1) (In the formula, X is the same or different and represents -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and represents -H, -F, an alkyl group or a fluoroalkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.) However, at least one of X, Y, and Z contains a fluorine atom.) The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and contains an ether bond between carbon atoms. When the coating composition of the present disclosure contains polymer (1), the aggregation suppression properties of the coating composition during stirring are improved. The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and contains an ether bond between carbon atoms.

[0225] In general formula (1), X is -H or -F. Both Xs may be -F, or at least one X may be -H. For example, one X may be -F and the other may be -H, or both Xs may be -H.

[0226] In general formula (1), Y is -H, -F, an alkyl group or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The Y may be -H, -F or -CF ３ is preferred, and —F is more preferred.

[0227] In general formula (1), Z's may be the same or different and are -H, -F, an alkyl group, or a fluoroalkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The Z's may be -H, -F, or -CF ３ is preferred, and —F is more preferred.

[0228] In the general formula (1), at least one of X, Y, and Z contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0229] In the general formula (1), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond.

[0230] The number of carbon atoms in the fluorine-containing alkylene group is preferably 2 or more. The number of carbon atoms in the fluorine-containing alkylene group is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. Examples of the fluorine-containing alkylene group include -CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２CH ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２ The fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0231] The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, and even more preferably 12 or less. The fluorine-containing alkylene group having an ether bond is, for example, a group represented by the general formula: (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 1 to 10; s1 is 0 or 1; and t1 is an integer of 0 to 5).

[0232] Specific examples of the fluorine-containing alkylene group having an ether bond include —CF ２ CF (CF ３ ) OCF ２ CF ２ -, -CF(CF ３ )CF ２ -O-CF(CF ３ )-,-(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ )-(wherein n is an integer from 1 to 10), -CF(CF ３ )CF ２ -O-CF(CF ３ ) CH ２ -, -(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ ) CH ２- (wherein n is an integer of 1 to 10), -CH ２ CF ２ CF ２ O-CH ２ CF ２ CH 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 CH ２ -, -CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ O-CF ２ CH ２ The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0233] In the general formula (1), A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group).

[0234] R ７ As the group, H or C １－１０ is preferably an organic group represented by the formula: １－４ More preferred are organic groups represented by the formula: １－４ More preferred are alkyl groups of the formula:

[0235] Examples of the metal atom include alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred.

[0236] M is —H, a metal atom, or —NR ７ ４ is preferred, and —H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or —NR ７ ４ is more preferred, and —H, —Na, —K, —Li or —NH ４ is more preferred, and —Na, —K or —NH ４ is even more preferred, and —Na or —NH ４ is particularly preferred, and —NH ４ is most preferred.

[0237] A is -COOM or -SO ３ M is preferred, and —COOM is more preferred.

[0238] Examples of the monomer represented by the general formula (1) include a monomer represented by the general formula (1a): ２ =CFCF ２ -O-(CF(CF ３ )CF ２ O) ｎ５ -CF (CF ３ )-A (1a) (wherein each X is the same and represents F or H, n5 represents 0 or an integer of 1 to 10, and A is as defined above).

[0239] In the general formula (1a), n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, in that PTFE particles having a small primary particle diameter can be obtained.

[0240] The polymer (1) may be a homopolymer of the monomer represented by the general formula (1a) or a copolymer with other monomers.

[0241] The polymerized unit (1) is preferably a polymerized unit (1A) based on a monomer represented by general formula (1A): CH ２ =CF(-CF ２—O—Rf-A) (1A) (wherein Rf and A are the same as defined above.)

[0242] The polymer (1) may be a homopolymer of the monomer represented by the general formula (1A) or a copolymer with other monomers.

[0243] Specific examples of the monomer represented by formula (1A) include the monomer represented by the general formula:

[0244]

[0245] (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 0 to 10; s1 is 0 or 1; t1 is an integer of 0 to 5, provided that Z ３ and Z ４ are both H, then p1+q1+r1+s1 is not 0; A is the same as defined above). More specifically,

[0246]

[0247] Among them,

[0248]

[0249] It is preferable that:

[0250] In the monomer represented by the general formula (1A), A in the formula (1A) is preferably -COOM, and particularly preferably CH ２ =CFCF ２ OCF (CF ３ ) COOM, and CH ２ =CFCF ２ OCF (CF ３ )CF ２ OCF (CF ３ )COOM (wherein M is as defined above), and CH ２ =CFCF ２ OCF (CF ３ ) COOM is more preferred.

[0251] Further, examples of the monomer represented by general formula (1) include a monomer represented by the following formula: CF ２ =CFCF ２ -O-Rf-A (wherein Rf and A are the same as above)

[0252] More specifically, etc.

[0253] The polymer (I) is also preferably a polymer (2) containing polymerized units (2) based on a monomer represented by general formula (2): CX ２ =CY(-O-Rf-A) (2) (In the formula, X's are the same or different and each represents -H or -F; Y represents -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf represents a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond or a keto group; and A is the same as defined above.)

[0254] In general formula (2), X is -H or -F. Both Xs may be -F, or at least one X may be -H. For example, one X may be -F and the other may be -H, or both Xs may be -H.

[0255] In general formula (2), Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. Y is -H, -F, or -CF ３ is preferred, and —F is more preferred.

[0256] In general formula (2), it is preferable that at least one of X and Y contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0257] In general formula (2), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, a fluorine-containing alkylene group having an ether bond having 2 to 100 carbon atoms, or a fluorine-containing alkylene group having a keto group having 2 to 100 carbon atoms. The fluorine-containing alkylene group having an ether bond having 2 to 100 carbon atoms is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and that contains an ether bond between carbon atoms.

[0258] The carbon number of the fluorine-containing alkylene group of Rf is preferably 2 or more, and more preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, and particularly preferably 5 or less. Examples of the fluorine-containing alkylene group include -CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２ CH ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２ -, -CF ２ CF ２ CF ２ -, CF ２ CF ２ CF ２ CF ２ The fluorine-containing alkylene group is preferably a perfluoroalkylene group, more preferably an unbranched linear perfluoroalkylene group.

[0259] The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less. The fluorine-containing alkylene group having an ether bond is, for example, a group represented by the general formula: (In the formula, Z １ is F or CF ３ ;Z ２ and Z３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 1 to 10; s1 is 0 or 1; and t1 is an integer of 0 to 5).

[0260] Specific examples of the fluorine-containing alkylene group having an ether bond include —CF ２ CF (CF ３ ) OCF ２ CF ２ -, -CF ２ CF (CF ３ ) OCF ２ CF ２ -, -CF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ -, -CF(CF ３ )CF ２ -O-CF(CF ３ )-,-(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ )-(wherein n is an integer from 1 to 10), -CF(CF ３ )CF ２ -O-CF(CF ３ ) CH ２ -, -(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ ) CH ２ - (wherein n is an integer of 1 to 10), -CH ２ CF ２ CF ２ O-CH ２ CF ２ CH 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 ２O-CF ２ CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CH ２ -, -CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ O-CF ２ CH ２ The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0261] The number of carbon atoms in the fluorine-containing alkylene group having a keto group is preferably 3 or more. The number of carbon atoms in the fluorine-containing alkylene group having a keto group is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less.

[0262] Specific examples of the fluorine-containing alkylene group having a keto group include: 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 -, -CF ２ CF (CF ３ )CO-CF ２ CF ２ CF ２ CF ２ The fluorine-containing alkylene group having a keto group is preferably a perfluoroalkylene group.

[0263] Water may be added to the keto group in the fluorine-containing alkylene group. Therefore, the monomer (2) may be a hydrate. Examples of the fluorine-containing alkylene group in which water is added to the keto group include —CF ２ CF (CF ３)C(OH) ２ -CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ CF ２ CF ２ - etc.

[0264] The monomer represented by general formula (2) is preferably at least one selected from the group consisting of monomers represented by general formulas (2a), (2b), (2c), (2d), (2e), (2f) and (2g). ２ =CF-O-(CF ２ ) ｎ１ -A (2a) (wherein n1 represents an integer of 1 to 10, and A is the same as defined above) CF ２ =CF-O-(CF ２ C (CF ３ ) F) ｎ２ -A (2b) (wherein n2 represents an integer of 1 to 5, and A is as defined above) CF ２ =CF-O-(CFX １ ) ｎ３ -A (2c) (wherein, X １ is F or CF ３ wherein n3 represents an integer of 1 to 10, and A is as defined above. ２ =CF-O-(CF ２ CFX １ O) ｎ４ -(CF ２ ) ｎ６ -A (2d) (wherein n4 represents an integer of 1 to 10, n6 represents an integer of 1 to 3, and A and X １ is the same as the definition above.) CF ２=CF-O-(CF ２ CF ２ CFX １ O) ｎ５ -CF ２ CF ２ CF ２ -A (2e) (wherein n5 represents an integer of 0 to 10, and A and X １ is the same as the definition above.) CF ２ =CF-O-(CF ２ ) ｎ７ -O-(CF ２ ) ｎ８ -A (2f) (wherein n7 represents an integer of 1 to 10, n8 represents an integer of 1 to 3, and A is as defined above.) CF ２ =CF[OCF ２ CF (CF ３ )] ｎ９ O (CF ２ ) ｎ１０ O[CF(CF ３ )CF ２ O] ｎ１１ CF (CF ３ )-A (2g) (wherein n9 represents an integer of 0 to 5, n10 represents an integer of 1 to 8, and n11 represents an integer of 0 to 5. A is as defined above.)

[0265] In the general formula (2a), n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less.

[0266] Examples of the monomer represented by general formula (2a) include CF ２ =CF-O-CF ２ COOM, C.F. ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(O(CF ２ ) ３ COOM), C.F. ２ =CF(OCF ２ CF ２ SO ３ M), CF ２ = CFOCF ２ SO ３ M., C.F. ２ = CFOCF ２ CF２ CF ２ SO ３ M (wherein M is as defined above).

[0267] In general formula (2b), n2 is preferably an integer of 3 or less, from the viewpoint of inhibiting aggregation during stirring of the resulting coating composition.

[0268] In the general formula (2c), n3 is preferably an integer of 5 or less from the viewpoint of water solubility, A is preferably -COOM, and M is preferably H, Na, or NH ４ It is preferable that:

[0269] In general formula (2d), X １ is -CF in terms of the ability to inhibit aggregation during stirring of the coating composition. ３ n4 is preferably an integer of 5 or less in terms of water solubility, A is preferably -COOM, and M is H, Na, or NH ４ It is preferable that:

[0270] Examples of the monomer represented by general formula (2d) include CF ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ SO ３ M., C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ SO ３ M., C.F. ２ = CFOCF ２ CF (CF３ ) OCF ２ CF ２ CF ２ SO ３ M (wherein M is H, NH ４ or an alkali metal.

[0271] In the general formula (2e), n5 is preferably an integer of 5 or less from the viewpoint of water solubility, A is preferably -COOM, and M is preferably H or NH ４ It is preferable that:

[0272] Examples of the monomer represented by general formula (2e) include CF ２ = CFOCF ２ CF ２ CF ２ COOM (wherein M is H, Na, NH ４ or an alkali metal.

[0273] In the general formula (2f), n7 is preferably an integer of 5 or less in terms of water solubility, and A is -COOM or -SO ３ M is preferred, and -COOM is more preferred. M is H, Na, K or NH ４ It is preferable that:

[0274] Examples of the monomer represented by general formula (2f) include CF ２ =CF-O-(CF ２ ) ３ -O-CF ２ -COOM (wherein M is H, NH ４ or an alkali metal.

[0275] 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 A is -COOM or -SO ３ M is preferred, and -COOM is more preferred. M is H, Na, K or NH ４ It is preferable that:

[0276] Examples of the monomer represented by general formula (2g) include CF ２= CFO (CF ２ ) ２ OCF (CF ３ ) COOM, C.F. ２ = CFOCF ２ CF ２ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ OCF (CF ３ ) COOM, C.F. ２ =CF[OCF ２ CF (CF ３ )] ２ O (CF ２ ) ２ O[CF(CF ３ )CF ２ O]CF(CF ３ ) COOM, C.F. ２ =CF[OCF ２ CF (CF ３ )] ３ O (CF ２ ) ２ O[CF(CF ３ )CF ２ O] ３ CF (CF ３ ) COOM (wherein M is H, NH ４ or an alkali metal.

[0277] The polymer (I) is also preferably a polymer (3) containing polymerized units (3) based on a monomer represented by general formula (3): CX ２ =CY(-Rf-A) (3) (In the formula, X is the same or different and represents -H or -F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond; and A is the same as defined above.)

[0278] The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and that contains an ether bond between carbon atoms.

[0279] In general formula (3), Rf is preferably a fluorine-containing alkylene group having 1 to 40 carbon atoms. In general formula (3), at least one of X and Y preferably contains a fluorine atom.

[0280] The monomer represented by the general formula (3) is represented by the general formula (3a): CF ２ =CF-(CF ２ ) ｎ１ -A (3a) (wherein n1 represents an integer of 1 to 10, and A is as defined above), and a monomer represented by the general formula (3b): CF ２ =CF-(CF ２ C (CF ３ ) F) ｎ２ -A (3b) (wherein n2 represents an integer of 1 to 5, and A is as defined above) is preferred.

[0281] In the general formula (3a) and the general formula (3b), A is —SO ３ M or -COOM is preferred, where M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. ７ represents H or an organic group.

[0282] In the general formula (3a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. A is preferably -COOM, and M is H or NH. ４ It is preferable that:

[0283] Examples of the monomer represented by general formula (3a) include CF ２ =CFCF ２ COOM (wherein M is as defined above).

[0284] In general formula (3b), n2 is preferably an integer of 3 or less from the viewpoint of the aggregation suppression property during stirring of the resulting coating composition, A is preferably -COOM, and M is preferably H or NH ４ It is preferable that:

[0285] Next, a preferred structure when m in general formula (I) is an integer of 2 or more will be described.

[0286] It is also preferable that the polymer (I) is a polymer (4) containing polymerized units (4) based on at least one monomer selected from the group consisting of monomers represented by general formula (4a) and general formula (4b). ２ =CF-CF ２ -O-Q Ｆ１ -CF(-Q Ｆ２ -CZ １ Z ２ -A) ２ (4a) (wherein, Z １ , Z ２ and A is the same as defined above, Q Ｆ１ and Q Ｆ２ are the same or different and are a single bond, a fluorine-containing alkylene group which may contain an ether bond between carbon atoms, or a fluorine-containing oxyalkylene group which may contain an ether bond between carbon atoms. ２ =CF-O-Q Ｆ１ -CF(-Q Ｆ２ -CZ １ Z ２ -A) ２ (4b) (wherein, Z １ , Z ２ , A, Q Ｆ１ and Q Ｆ２ is the same as above)

[0287] The monomers represented by general formula (4a) and general formula (4b) include: etc.

[0288] The polymer (I) is preferably at least one selected from the group consisting of the polymer (1), the polymer (2) and the polymer (3), and more preferably the polymer (1).

[0289] The polymer (I) may be a homopolymer consisting of only the polymerized unit (I), or may be a copolymer containing the polymerized unit (I) and a polymerized unit based on another monomer copolymerizable with the monomer represented by the general formula (I). From the viewpoint of solubility in an aqueous medium, a homopolymer consisting of only the polymerized unit (I) is preferred. The polymerized units (I) may be the same or different in each occurrence, and the polymer (I) may contain polymerized units (I) based on two or more different monomers represented by the general formula (I).

[0290] The other monomers include those represented by the general formula CFR=CR ２ (wherein R is independently H, F or a perfluoroalkyl group having 1 to 4 carbon atoms) is preferred. As the other monomer, a fluorine-containing ethylenic monomer having 2 or 3 carbon atoms is preferred. As the other monomer, for example, CF ２ =CF ２ , C.F. ２ = CFCl, CH ２ =CF ２ , CFH=CH ２ , CFH=CF ２ , C.F. ２ =CFCF ３ , C.H. ２ =CFCF ３ , C.H. ２ = CHCF ３ , CHF=CHCF ３ (E form), CHF=CHCF ３ Among them, tetrafluoroethylene (CF ２ =CF ２ ), chlorotrifluoroethylene (CF ２ =CFCl) and vinylidene fluoride (CH ２ =CF ２), and more preferably at least one selected from the group consisting of tetrafluoroethylene and vinylidene fluoride. Therefore, the polymerized units based on the other monomer are preferably polymerized units based on tetrafluoroethylene. The polymerized units based on the other monomer may be the same or different in each occurrence, and polymer (I) may contain polymerized units based on two or more different other monomers.

[0291] The other monomers also include those represented by the general formula (n1-2):

[0292]

[0293] (In the formula, X １ , X ２ are the same or different and are H or F; X ３ are H, F, Cl, CH ３ or CF ３ ;X ４ , X ５ are the same or different and are H or F; a and c are the same or different and are 0 or 1. ３ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond).

[0294] Specifically, CH ２ =CFCF ２ -O-Rf ３ , C.F. ２ ═CF—O—Rf ３ , C.F. ２ =CFCF ２ -O-Rf ３ , C.F. ２ =CF-Rf ３ , C.H. ２ =CH-Rf ３ , C.H. ２ =CH-O-Rf ３ (wherein, Rf ３ is the same as the above formula (n1-2).

[0295] Examples of the other monomer include a monomer of the formula (n2-1):

[0296]

[0297] (In the formula, X ９ is H, F or CH ３ ; Rf ４ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond). ４ The base is

[0298]

[0299] (wherein d3 is an integer of 1 to 4; e3 is an integer of 1 to 10).

[0300] Examples of the other monomer include a monomer represented by formula (n2-2): CH ２ =CHO-Rf ５ (n2-2) (wherein, Rf ５ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond), and

[0301] Specific examples of the monomer of general formula (n2-2) include:

[0302]

[0303] (wherein e6 is an integer of 1 to 10) are preferred.

[0304] More specifically,

[0305]

[0306] Examples include:

[0307] Others include those represented by the general formula (n2-3): CH ２ =CHCH ２ O-Rf ６ (n2-3) (wherein, Rf ６ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and an ether bond), a fluorine-containing allyl ether represented by the general formula (n2-4): CH ２ =CH-Rf ７ (n2-4) (wherein, Rf ７is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond), and the like.

[0308] Specific examples of the monomers represented by general formulas (n2-3) and (n2-4) include:

[0309]

[0310] Examples of such monomers include:

[0311] The polymer (I) usually has a terminal group. The terminal group is a terminal group generated during polymerization, and typical terminal groups are independently selected from hydrogen, iodine, bromine, linear or branched alkyl groups, and linear or branched fluoroalkyl groups, and may optionally contain at least one catenary heteroatom. The alkyl group or fluoroalkyl group preferably has 1 to 20 carbon atoms. These terminal groups are generally generated from the initiator or chain transfer agent used in forming the polymer (I), or are generated during the chain transfer reaction.

[0312] In the polymer (I), the content of the polymerized units (I) relative to all polymerized units is, in order of preference, 1.0 mol% or more, 3.0 mol% or more, 5.0 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, and 90 mol% or more. The content of the polymerized units (I) is particularly preferably substantially 100 mol%, and the polymer (I) is most preferably composed only of the polymerized units (I).

[0313] In the polymer (I), the content of polymerization units based on other monomers copolymerizable with the monomer represented by general formula (I) is, in order of preference, 99.0 mol% or less, 97.0 mol% or less, 95.0 mol% or less, 90 mol% or less, 80 mol% or less, 70 mol% or less, 60 mol% or less, 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, and 10 mol% or less, based on all polymerization units. It is particularly preferable that the content of polymerization units based on other monomers copolymerizable with the monomer represented by general formula (I) is substantially 0 mol%, and it is most preferable that the polymer (I) does not contain polymerization units based on other monomers.

[0314] The number average molecular weight of the polymer (I) is 0.1 × 10 ４ More than 0.2 × 10 ４ More preferably, 0.3 × 10 ４ More preferably, 0.4 × 10 ４ More preferably, 0.5 × 10 ４ More preferably, 1.0 x 10 ４ More preferably, 3.0 × 10 ４ More particularly, 3.1 × 10 ４ More than 75.0×10 is most preferable. ４ Preferably, 50.0 x 10 ４ More preferably, 40.0 x 10 ４ More preferably, 30.0 x 10 ４ The following is particularly preferred: 20.0 x 10 ４ The following are particularly preferred. The number average molecular weight and weight average molecular weight are values ​​calculated by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. When measurement by GPC is not possible, the number average molecular weight of polymer (I) can be determined from the correlation between the number average molecular weight calculated from the number of terminal groups obtained by NMR, FT-IR, etc. and the melt flow rate. The melt flow rate can be measured in accordance with JIS K 7210.

[0315] The lower limit of the weight average molecular weight of the polymer (I) is, in order of preference, 0.2 × 10 ４ That's it, 0.4 x 10４ That's it, 0.6 x 10 ４ That's it, 0.8 x 10 ４ That's it, 1.0 x 10 ４ That's it, 2.0 x 10 ４ That's it, 5.0 x 10 ４ That's it, 10.0 x 10 ４ That's it, 15.0 x 10 ４ That's it, 20.0 x 10 ４ That's it, 25.0 x 10 ４ The upper limit of the weight average molecular weight of the polymer (I) is, in order of preference, 150.0×10 ４ Below, 100.0 x 10 ４ Below, 60.0 x 10 ４ Below, 50.0 x 10 ４ Below, 40.0 x 10 ４ The following is the result.

[0316] The polymer (I) preferably has an ion exchange ratio (IXR) of 53 or less. The IXR is defined as the number of carbon atoms in the polymer main chain relative to the ionic group. ２ F) is not considered an ionizable group for purposes of determining IXR.

[0317] IXR is preferably 0.5 or more, more preferably 1 or more, even more preferably 3 or more, even more preferably 4 or more, particularly preferably 5 or more, and particularly preferably 8 or more. IXR is more preferably 43 or less, more preferably 33 or less, and particularly preferably 23 or less.

[0318] The ion exchange capacity of the polymer (I) is, in order of preference, 0.80 meg / g or more, 1.50 meg / g or more, 1.75 meg / g or more, 2.00 meg / g or more, 2.20 meq / g or more, more than 2.20 meq / g, 2.50 meg / g or more, 2.60 meg / g or more, 3.00 meg / g or more, and 3.50 meg / g or more. The ion exchange capacity is the content of ionic groups (anionic groups) in the polymer (I) and is calculated from the composition of the polymer (I).

[0319] In polymer (I), the ionic (anionic) groups are typically distributed along the polymer backbone. The polymer (I) comprises a polymer backbone with recurring side chains attached to the backbone, which preferably carry ionic groups.

[0320] Preferably, polymer (I) comprises ionic groups having a pKa of less than 10, more preferably less than 7. The ionic groups of polymer (I) are preferably selected from the group consisting of sulfonate, carboxylate, phosphonate, and phosphate.

[0321] The terms "sulfonate, carboxylate, phosphonate, and phosphate" are intended to refer to the respective salts or the respective acids capable of forming salts. When salts are used, preferably the salts are alkali metal or ammonium salts. A preferred ionic group is a sulfonate group.

[0322] The polymer (I) is preferably water-soluble. Water-soluble means the property of being easily dissolved or dispersed in an aqueous medium. The particle size of the water-soluble polymer (I) cannot be measured by dynamic light scattering (DLS), for example, or the particle size is 10 nm or less.

[0323] The viscosity of an aqueous solution of polymer (I) is preferably 5.0 mPa.s or more, more preferably 8.0 mPa.s or more, even more preferably 10.0 mPa.s or more, particularly preferably 12.0 mPa.s or more, and most preferably 14.0 mPa.s or more, and is preferably 100.0 mPa.s or less, more preferably 50.0 mPa.s or less, even more preferably 25.0 mPa.s or less, and especially preferably 20.0 mPa.s or less.

[0324] The viscosity of the aqueous solution of polymer (I) can be determined by adjusting the content of polymer (I) in the aqueous solution to 33 mass % based on the aqueous solution, and measuring the viscosity of the obtained aqueous solution at 20°C using a tuning fork vibro viscometer (model number: SV-10) manufactured by A&D Co., Ltd.

[0325] The critical micelle concentration (CMC) of the polymer (I) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less.

[0326] The critical micelle concentration of the polymer (I) can be determined by measuring the surface tension, for example, using a surface tensiometer CBVP-A3 manufactured by Kyowa Interface Science Co., Ltd.

[0327] The acid value of the polymer (I) is preferably 60 or more, more preferably 90 or more, even more preferably 120 or more, particularly preferably 150 or more, and most preferably 180 or more. The upper limit is not particularly limited, but is preferably 300 or less.

[0328] The acid value of the polymer (I) is determined by the amount of anionic groups other than the acid functional groups, such as —COOM and —SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ When the compound has a group (H or an organic group), these groups can be converted into acid groups and then measured by acid-base titration.

[0329] The polymer (I) can be produced by a conventionally known method except for using the above-mentioned monomers.

[0330] In the first coating composition of the present disclosure, the content of polymer (I) is 2000 ppm by mass or less relative to the coating composition. The content of polymer (I) in the first coating composition of the present disclosure is preferably 1500 ppm by mass or less, and may also be 1000 ppm by mass or less, 500 ppm by mass or less, or 250 ppm by mass or less. Furthermore, the content of polymer (I) in the first coating composition of the present disclosure is preferably 0.1 ppm by mass or more, and more preferably 0.5 ppm by mass or more, relative to the coating composition.

[0331] In the first coating composition of the present disclosure, the content of polymer (I) relative to the fluororesin is preferably 0.1 ppm by mass or more, more preferably 0.2 ppm by mass or more, even more preferably 0.5 ppm by mass or more, particularly preferably 1.0 ppm by mass or more, and most preferably 3.0 ppm by mass or more. The content of polymer (I) relative to the fluororesin may be, for example, 500 ppm by mass or more. Furthermore, in the first coating composition of the present disclosure, the content of polymer (I) relative to the fluororesin is preferably 1.5% by mass or less, more preferably 1.0% by mass or less, and may be 0.5% by mass or less, 0.4% by mass or less, or 0.3% by mass or less.

[0332] In the second and third coating compositions of the present disclosure, the content of polymer (I) is preferably 2000 ppm by mass or less, more preferably 1500 ppm by mass or less, and may be 1000 ppm by mass or less, 500 ppm by mass or less, or 250 ppm by mass or less, relative to the coating composition. Furthermore, the content of polymer (I) in the second and third coating compositions of the present disclosure is preferably 0.1 ppm by mass or more, more preferably 0.5 ppm by mass or more, relative to the coating composition.

[0333] In the second and third coating compositions of the present disclosure, the content of polymer (I) in the coating composition is preferably 0.1 mass ppm or more, more preferably 0.2 mass ppm or more, even more preferably 0.5 mass ppm or more, particularly preferably 1.0 mass ppm or more, and most preferably 3.0 mass ppm or more, relative to PTFE. The content of polymer (I) may be, for example, 500 mass ppm or more, relative to PTFE. Furthermore, in the second and third coating compositions of the present disclosure, the content of polymer (I) is preferably 1.5 mass% or less, more preferably 1.0 mass% or less, and may also be 0.5 mass% or less, 0.4 mass% or less, or 0.3 mass% or less, relative to PTFE.

[0334] The content of polymer (I) in the coating composition of the present disclosure can be determined by solid-state NMR measurement. Measurement methods for each polymer are described in Publication No. 2012 / 082707, WO 2012 / 082703, WO 2012 / 082451, WO 2006 / 135825, WO 2004 / 067588, WO 2009 / 068528, JP 2004-075978, JP 2001-226436, WO 1992 / 017635, WO 2014 / 069165, JP 11-181009, etc. As a method for measuring the content of polymer (I), the measurement methods for each polymer described therein can be used.

[0335] The content of dimers and trimers of the monomer represented by general formula (I) in the coating composition of the present disclosure is preferably 1.0% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, particularly preferably 0.001% by mass or less, and most preferably 0.0001% by mass or less, relative to polymer (I).

[0336] The content of dimers and trimers of the monomer represented by general formula (I) in the coating composition of the present disclosure can be measured by the same method as the content of dimers and trimers in polymer (I) described below.

[0337] <Aqueous Medium> The aqueous medium refers to a liquid containing water. The aqueous medium is not particularly limited as long as it contains water, and may contain water and, for example, a fluorine-free organic solvent such as an alcohol, ether, or ketone, and / or a fluorine-containing organic solvent having a boiling point of 40°C or lower. The aqueous medium is preferably a mixture of water and an organic solvent. The water content in the coating composition of the present disclosure is preferably 20.0% by mass to 60.0% by mass. Furthermore, from the viewpoint of improving the dispersion stability of the coating composition when the solid content concentration of the coating composition is high, the water content in the coating composition of the present disclosure may be 40.0% by mass to 50.0% by mass.

[0338] <Nonionic Surfactant> The third coating composition of the present disclosure contains a nonionic surfactant. The first coating composition and the second coating composition of the present disclosure preferably contain a nonionic surfactant.

[0339] The nonionic surfactants described above typically contain no charged groups and have a hydrophobic portion that is a long hydrocarbon chain. The hydrophilic portion of the nonionic surfactant contains a water-soluble functional group, such as an ethylene ether chain derived from polymerization with ethylene oxide.

[0340] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerol esters, and derivatives thereof.

[0341] Specific examples of polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene behenyl ether.

[0342] Specific examples of polyoxyethylene alkylphenyl ethers include polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether.

[0343] Specific examples of polyoxyethylene alkyl esters include polyethylene glycol monolaurate, polyethylene glycol monooleate, and polyethylene glycol monostearate.

[0344] Specific examples of sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate.

[0345] Specific examples of polyoxyethylene sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monostearate.

[0346] Specific examples of glycerol esters include glycerol monomyristate, glycerol monostearate, and glycerol monooleate.

[0347] Specific examples of the above derivatives include polyoxyethylene alkylamines, polyoxyethylene alkylphenyl-formaldehyde condensates, polyoxyethylene alkyl ether phosphates, and the like.

[0348] The ethers and esters may have an HLB value of 10-18.

[0349] Examples of nonionic surfactants include Triton (registered trademark) X series (X15, X45, X100, etc.), Tergitol (registered trademark) 15-S series, Tergitol (registered trademark) TMN series (TMN-6, TMN-10, TMN-100, etc.), and Tergitol (registered trademark) L series, all manufactured by The Dow Chemical Company; and Pluronic (registered trademark) R series (31R1, 17R2, 10R5, 25R4 (m to 22, n to 23) and Iconol (registered trademark) TDA series (TDA-6, TDA-9, TDA-10), all manufactured by BASF.

[0350] The nonionic surfactants themselves provide a polymerization field and can also act as nucleation sites by initially transferring radicals to give many low molecular weight fluoropolymers.

[0351] The nonionic surfactant is preferably a nonionic surfactant that does not contain fluorine.For example, ether-type nonionic surfactants such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, etc.; polyoxyethylene derivatives such as ethylene oxide / propylene oxide block copolymer, etc.; ester-type nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, etc.; amine-based nonionic surfactants such as polyoxyethylene alkylamine, alkyl alkanolamide, etc.; etc. Among them, polyoxyethylene alkyl ether is preferred.

[0352] In the above nonionic surfactants, the hydrophobic group may be any of an alkylphenol group, a linear alkyl group, and a branched alkyl group.

[0353] The nonionic surfactant is preferably a nonionic surfactant represented by general formula (i): ６-O-A １ -H (i) (wherein, R ６ is a linear or branched primary or secondary alkyl group having 8 to 18 carbon atoms, and A １ is a polyoxyalkylene chain.

[0354] In general formula (i), R ６ The number of carbon atoms in R is preferably 10 to 16, and more preferably 12 to 16. ６ When the carbon number of R is 16 or less, the composition is likely to have excellent aggregation suppression properties during stirring. ６ If the carbon number exceeds 18, the flow temperature is high and the copolymer is difficult to handle.

[0355] The above R ６ is represented by the following general formula (i-1): CH ２ R ３１ R ３２ - (i-1) (wherein, R ３１ represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, R ３２ represents an alkyl group having 1 to 17 carbon atoms, and R ３１ and R ３２ The total number of carbon atoms in R is 7 to 17. ３１ is more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, even more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and even more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. ３２ As the alkyl group, an alkyl group having 1 to 15 carbon atoms is more preferable, an alkyl group having 1 to 14 carbon atoms is even more preferable, and an alkyl group having 1 to 13 carbon atoms is even more preferable.

[0356] The above R ６ is preferably an alkyl group having 8 to 18 carbon atoms and an average number of methyl groups of 2.0 or more. ３ The average number of methyl groups in R is more preferably 2.5 or more, even more preferably 3.0 or more, even more preferably 3.5 or more, and particularly preferably 4.0 or more. ３ The upper limit of the average number of methyl groups is preferably 12 or less, more preferably 10 or less, and even more preferably 8 or less.

[0357] In addition, the above R６ The average number of methyl groups per molecule is preferably 4.0 or more, more preferably 4.3 or more, even more preferably 4.7 or more, and most preferably 5.0 or more. ６ In this specification, the average number of methyl groups is determined by adding methanol to a sample, performing Soxhlet extraction, and then measuring the amount of the extracted １ This value is determined by measuring with H-NMR.

[0358] The polyoxyalkylene chain may be composed of oxyethylene and oxypropylene. It is a polyoxyalkylene chain having an average repeat number of 5 to 20 oxyethylene groups and an average repeat number of 0 to 2 oxypropylene groups, and is a hydrophilic group. The number of oxyethylene units may include either a broad or narrow unimodal distribution, which is usually provided, or a broader or bimodal distribution obtained by blending. When the average repeat number of oxypropylene groups is greater than 0, the oxyethylene groups and oxypropylene groups in the polyoxyalkylene chain may be arranged in a block or random configuration. From the viewpoints of the viscosity of the composition and the ability to inhibit aggregation during stirring, a polyoxyalkylene chain having an average repeat number of 7 to 12 oxyethylene groups and an average repeat number of 0 to 2 oxypropylene groups is preferred. In particular, A １ When the number of oxypropylene groups is 0.5 to 1.5 on average, low foaming properties are favorable, and this is preferred.

[0359] More preferably, R ６ is (R')(R'')HC-, where R' and R'' are the same or different straight, branched, or cyclic alkyl groups having a total of at least 5, preferably 7 to 17, carbon atoms. Preferably, at least one of R' or R'' is a branched or cyclic hydrocarbon group.

[0360] Specific examples of the polyoxyethylene alkyl ether include C １３ H ２７ -O-(C ２ H ４ O) １０ -H, C１２ H ２５ -O-(C ２ H ４ O) １０ -H, C １０ H ２１ CH (CH ３ ) CH ２ -O-(C ２ H ４ O) ９ -H, C １３ H ２７ -O-(C ２ H ４ O) ９ -(CH(CH ３ ) CH ２ O) -H, C １６ H ３３ -O-(C ２ H ４ O) １０ -H, HC(C ５ H １１ ) (C ７ H １５ )—O—(C ２ H ４ O) ９ -H, etc. Commercially available polyoxyethylene alkyl ethers include, for example, Genapol X080 (product name, manufactured by Clariant), the Noigen TDS series (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) such as Noigen TDS-80 (trade name) and Noigen TDS-100 (trade name), the Leocol TD series (manufactured by Lion Corporation) such as Leocol TD-90 (trade name), the Lionol (registered trademark) TD series (manufactured by Lion Corporation), the T-Det A series (manufactured by Harcros Chemicals) such as T-Det A138 (trade name), the Tergitol (registered trademark) 15-S series (manufactured by Dow Chemical Company), and Dispanol TOC (trade name, manufactured by NOF Corporation).

[0361] Also preferred is an ethoxylate of 2,6,8-trimethyl-4-nonanol having an average of about 4 to about 18 ethylene oxide units, an ethoxylate of 2,6,8-trimethyl-4-nonanol having an average of about 6 to about 12 ethylene oxide units, or a mixture thereof. Nonionic surfactants of this type are also commercially available, for example, as TERGITOL TMN-6, TERGITOL TMN-10, and TERGITOL TMN-100X (all trade names, manufactured by The Dow Chemical Company).

[0362] The hydrophobic group of the nonionic surfactant may be any of an alkylphenol group, a linear alkyl group, and a branched alkyl group. For example, the nonionic surfactant may be a nonionic surfactant represented by the general formula (ii): ７ -C ６ H ４ -O-A ２ -H (ii) (wherein, R ７ is a linear or branched primary or secondary alkyl group having 4 to 12 carbon atoms, and A ２ is a polyoxyalkylene chain.) Specific examples of the nonionic surfactant include Triton X-100 (trade name, manufactured by The Dow Chemical Company).

[0363] The nonionic surfactant also includes polyol compounds. Specific examples include those described in International Publication No. 2011 / 014715. Typical examples of polyol compounds include compounds having one or more sugar units as polyol units. The sugar units may be modified to contain at least one long chain. Suitable polyol compounds containing at least one long chain moiety include, for example, alkyl glycosides, modified alkyl glycosides, sugar esters, and combinations thereof. Sugars include, but are not limited to, monosaccharides, oligosaccharides, and sorbitan. Monosaccharides include pentoses and hexoses. Typical examples of monosaccharides include ribose, glucose, galactose, mannose, fructose, arabinose, and xylose. Oligosaccharides include oligomers of 2 to 10 identical or different monosaccharides. Examples of oligosaccharides include, but are not limited to, sucrose, maltose, lactose, raffinose, and isomaltose.

[0364] Typically, sugars suitable for use as polyol compounds include cyclic compounds containing a five-membered ring with four carbon atoms and one heteroatom (typically oxygen or sulfur, but preferably oxygen), or a six-membered ring with five carbon atoms and one heteroatom, preferably oxygen, as described above. These further contain at least two or at least three hydroxy groups (—OH groups) attached to the carbon ring atoms. Typically, the sugars are modified in that one or more of the hydrogen atoms of the hydroxy groups (and / or hydroxyalkyl groups) attached to the carbon ring atoms are replaced with a long-chain residue such that an ether or ester bond is created between the long-chain residue and the sugar moiety. Sugar-based polyols may contain one sugar unit or multiple sugar units. One sugar unit or multiple sugar units may be modified with a long-chain moiety as described above. Specific examples of sugar-based polyol compounds include glycosides, sugar esters, sorbitan esters, and mixtures and combinations thereof.

[0365] A preferred class of polyol compounds are the alkyl or modified alkyl glucosides. These classes of surfactants contain at least one glucose moiety. (wherein x represents 0, 1, 2, 3, 4, or 5; R １ and R ２ independently represent H or a long chain unit containing at least 6 carbon atoms, with the proviso that R １ and R ２ and at least one of R is not H. １ and R ２ Typical examples of alkyl polyglucosides include fatty alcohol residues. Examples of fatty alcohols include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), eicosanoic acid, and combinations thereof. While the above formula represents a specific example of an alkyl polyglucoside showing glucose in the pyranose form, it is understood that other sugars or sugars of the same sugar but in different enantiomeric or diastereomeric forms may also be used. Alkyl glucosides can be obtained, for example, by the acid-catalyzed reaction of glucose, starch, or n-butyl glucoside with aliphatic alcohols, which typically results in a mixture of various alkyl glucosides (Alkylpolygylcoside, Rompp, Lexikon Chemie, Version 2.0, Stuttgart / New York, George Thieme Verlag, 1999). Examples of aliphatic alcohols include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tetradecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), eicosanoic acid, and combinations thereof. Alkyl glucosides are also commercially available from Cognis GmbH, Dusseldorf, Germany under the tradenames GLUCOPON or DISPONIL.

[0366] Other nonionic surfactants include difunctional block copolymers supplied by BASF as part of the Pluronic® R series, and tridecyl alcohol alkoxylates supplied by BASF as part of the Iconol® TDA series.

[0367] The nonionic surfactant is preferably at least one selected from the group consisting of nonionic surfactants represented by general formula (i) and nonionic surfactants represented by general formula (ii), and more preferably a nonionic surfactant represented by general formula (i).

[0368] The nonionic surfactant preferably does not contain an aromatic moiety.

[0369] The nonionic surfactant may be a mixture of two different nonionic surfactants, for example, A １ and a compound having a polyoxyalkylene chain with an average number of oxyethylene units of 7.0 to 12.0 and an average number of oxypropylene units of 0.0 to 2.0, １ In addition, for example, the compound A in the above general formula (i) may be a mixture of the compound A and a compound A in the above general formula (i). １ and a compound having an average number of oxyethylene units of 7.0 or more and less than 10.0, and A １ and a compound having a polyoxyalkylene chain with an average number of oxyethylene units of 10.0 or more and 12.0 or less.

[0370] The nonionic surfactant preferably has an HLB of 13.00 or more, more preferably 13.20 or more, even more preferably 14.00 or more, even more preferably 14.05 or more, and particularly preferably 14.10 or more. The HLB is preferably 14.50 or less, more preferably 14.40 or less, even more preferably 14.30 or less, even more preferably 14.20 or less, and particularly preferably 14.15 or less. The HLB is a value calculated using Griffin's formula [HLB=E / 5 (where E is the weight percent of ethylene oxide in the molecule); HLB=(E+P) / 5 (where E is as defined above, P is the weight percent of polyhydric alcohol in the molecule); HLB=20(1-S / N) / 5 (where S is the saponification value of the ester, and N is the neutralization value of the fatty acid constituting the ester)]. When two or more nonionic surfactants are used, the HLB is calculated from the HLB of each nonionic surfactant and its mass ratio. For example, if the nonionic surfactant with an HLB of 14.00 accounts for 60 mass% and the nonionic surfactant with an HLB of 15.00 accounts for 40 mass% of the total content of nonionic surfactants, the HLB is calculated as 14.00 × 0.6 + 15.00 × 0.4 = 14.40.

[0371] The coating composition of the present disclosure may contain two types of nonionic surfactants with different HLBs. For example, the coating composition of the present disclosure may contain a nonionic surfactant with an HLB of 13.00 or more but less than 14.10, and a nonionic surfactant with an HLB of 14.10 or more but less than 15.00. Adding nonionic surfactants with different HLBs can suppress foaming without adding an antifoaming agent. Also, for example, the coating composition of the present disclosure may contain a nonionic surfactant with an HLB of 13.00 or more but less than 13.50, and a nonionic surfactant with an HLB of 13.50 or more but less than 15.00 (preferably 14.50 or less, more preferably 14.00 or less).

[0372] The cloud point of a nonionic surfactant is a measure of the solubility of the surfactant in water. The cloud point of a nonionic surfactant is preferably 30 to 90°C, more preferably 35 to 85°C, even more preferably 40 to 80°C, and particularly preferably 45 to 75°C.

[0373] The coating composition of the present disclosure may contain two types of nonionic surfactants with different cloud points. For example, the coating composition of the present disclosure may contain a nonionic surfactant with a cloud point of 30°C or higher and 60°C or lower and a nonionic surfactant with a cloud point of more than 60°C and less than 90°C, or may contain a nonionic surfactant with a cloud point of 35 to 60°C and a nonionic surfactant with a cloud point of 65 to 80°C. The use of a nonionic surfactant with a high cloud point can improve aggregation suppression during stirring. Furthermore, the addition of nonionic surfactants with different cloud points can suppress foaming without the addition of an antifoaming agent. Furthermore, for example, the coating composition of the present disclosure may contain a nonionic surfactant with a cloud point of 30°C or higher and 60°C or lower and a nonionic surfactant with a cloud point of more than 60°C and less than 90°C, or may contain a nonionic surfactant with a cloud point of 35 to 60°C and a nonionic surfactant with a cloud point of 65 to 80°C.

[0374] The content of the nonionic surfactant in the first coating composition of the present disclosure is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 3.0% by mass or more, and particularly preferably 4.0% by mass or more, relative to the fluororesin. Furthermore, the content of the nonionic surfactant is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, particularly preferably 15% by mass or less, and most preferably 12% by mass or less, relative to the fluororesin. By keeping the content of the nonionic surfactant within the above range, the coating composition can be improved in its aggregation suppression properties during stirring.

[0375] The content of the nonionic surfactant in the second coating composition and the third coating composition of the present disclosure is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 3.0% by mass or more, and particularly preferably 4.0% by mass or more, relative to PTFE. Furthermore, the content of the nonionic surfactant is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, particularly preferably 15% by mass or less, and most preferably 12% by mass or less, relative to PTFE. By keeping the content of the nonionic surfactant within the above range, the aggregation suppression properties of the coating composition during stirring can be improved.

[0376] <Anionic hydrocarbon surfactant> The third coating composition of the present disclosure contains an anionic hydrocarbon surfactant. The first coating composition and the second coating composition of the present disclosure preferably contain an anionic hydrocarbon surfactant. Use of an anionic hydrocarbon surfactant can appropriately adjust the viscosity of the coating composition and improve the compatibility of pigments, fillers, and the like.

[0377] Anionic hydrocarbon surfactants typically have a hydrophilic portion, such as a carboxylate, sulfonate, or sulfate, and a hydrophobic portion, which is a long chain hydrocarbon moiety, such as an alkyl.

[0378] Examples of anionic hydrocarbon surfactants include Versatic (registered trademark) 10 manufactured by Resolution Performance Products and Avanel S series (S-70, S-74, etc.) manufactured by BASF.

[0379] The anionic hydrocarbon surfactant may be R-L-M (wherein R is a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent, and when the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or may form a ring; L is -ArSO ３ － , -SO ３－ , -SO ４ -, -PO ３ － or -COO － and M is H, a metal atom, or NR ５ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ５ is H or an organic group, -ArSO ３ － is an aryl sulfonate.

[0380] Specifically, CH 3 esters such as lauric acid and lauryl sulfate are ３ - (CH ２ ) ｎ -LM (wherein n is an integer of 6 to 17, and L and M are the same as above). A mixture in which R is an alkyl group having 12 to 16 carbon atoms and LM is a sulfate can also be used.

[0381] In addition, the anionic hydrocarbon surfactants include R ６ (-L-M) ２ (In the formula, R ６ is a linear or branched alkylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylene group having 3 or more carbon atoms which may have a substituent, and when the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocycle or may form a ring. ３ － , -SO ３ － , -SO ４ -, -PO ３ － or -COO － and M is H, a metal atom, or NR ５ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ５ is H or an organic group, -ArSO ３ －is an aryl sulfonate.

[0382] In addition, the anionic hydrocarbon surfactants include R ７ (-L-M) ３ (In the formula, R ７ is a linear or branched alkylidyne group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylidyne group having 3 or more carbon atoms which may have a substituent, and when the number of carbon atoms is 3 or more, it may contain a monovalent or divalent heterocycle or may form a ring. ３ － , -SO ３ － , -SO ４ -, -PO ３ － or -COO － and M is H, a metal atom, or NR ５ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ５ is H or an organic group. ３ － is an aryl sulfonate.

[0383] Anionic hydrocarbon surfactants also include siloxane hydrocarbon surfactants. Examples of siloxane hydrocarbon surfactants include those described in Silicone Surfactants, R. M. Hill, Marcel Dekker, Inc., ISBN: 0-8247-00104. The structure of siloxane hydrocarbon surfactants includes a distinct hydrophobic portion and a hydrophilic portion. The hydrophobic portion includes one or more dihydrocarbylsiloxane units, where the substituents on the silicone atoms are entirely hydrocarbons. These siloxane surfactants can also be considered hydrocarbon surfactants in the sense that the carbon atoms of the hydrocarbyl groups are entirely substituted with hydrogen atoms, although they may be substituted with halogens such as fluorine, i.e., the monovalent substituents on the carbon atoms of the hydrocarbyl groups are hydrogen.

[0384] The hydrophilic portion of the siloxane hydrocarbon surfactant may contain one or more polar moieties containing ionic groups such as sulfates, sulfonates, phosphonates, phosphate esters, carboxylates, carbonates, sulfosuccinates, taurates (as free acids, salts, or esters), phosphine oxides, betaines, betaine copolyols, and quaternary ammonium salts. The ionic hydrophobic portion may also contain ionically functionalized siloxane grafts. Examples of such siloxane hydrocarbon surfactants include polydimethylsiloxane-grafted (meth)acrylates, polydimethylsiloxane-grafted polyacrylate salts, and polydimethylsiloxane-grafted quaternary amines. The polar portion of the hydrophilic portion of the siloxane hydrocarbon surfactant may contain nonionic groups formed by polyethers such as polyethylene oxide (PEO) and mixed polyethylene oxide / propylene oxide polyethers (PEO / PPO); monosaccharides and disaccharides; and water-soluble heterocycles such as pyrrolidinone. The ratio of ethylene oxide to propylene oxide (EO / PO) can be varied in mixed polyethylene oxide / propylene oxide polyethers.

[0385] The hydrophilic portion of the siloxane hydrocarbon surfactant may also contain a combination of ionic and nonionic moieties. Such moieties include, for example, ionically end-functionalized or randomly functionalized polyethers or polyols. Preferred for the practice of the present disclosure are siloxanes with nonionic moieties, i.e., nonionic siloxane surfactants.

[0386] The arrangement of hydrophobic and hydrophilic moieties in the structure of the siloxane hydrocarbon surfactant may take the form of a diblock polymer (AB), a triblock polymer (ABA) (where "B" represents the siloxane portion of the molecule), or a multiblock polymer. Alternatively, the siloxane surfactant may comprise a graft polymer.

[0387] Siloxane hydrocarbon surfactants are also disclosed in US Pat. No. 6,841,616.

[0388] Siloxane-based anionic hydrocarbon surfactants include SilSense®, available from Noveon® Consumer Specialties of Lubrizol Advanced Materials, Inc. ＴＭ PE-100 silicone, SilSense ＴＭ CA-1 silicone and the like.

[0389] Examples of anionic hydrocarbon surfactants include the sulfosuccinate surfactant Lankropol® K8300 from Akzo Nobel Surface Chemistry LLC. Examples of sulfosuccinate surfactants include diisodecyl sulfosuccinate sodium salt (Emulsogen® SB10 from Clariant) and diisotridecyl sulfosuccinate sodium salt (Polirol® TR / LNA from Cesapinia Chemicals).

[0390] Anionic hydrocarbon surfactants include PolyFox® surfactants from Omnova Solutions, Inc. ＴＭ PF-156A, PolyFox ＴＭ PF-136A, etc.)

[0391] Examples of the anionic hydrocarbon surfactant include those represented by the general formula (α): １０ -COOM (α) (wherein, R １０ is a monovalent organic group containing one or more carbon atoms. M is H, a metal atom, NR １１ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R １１ R is H or an organic group, and may be the same or different. １１ As H or C １－１０is preferably an organic group represented by the formula: １－４ From the viewpoint of surface activity, the organic group R １０ The number of carbon atoms in R is preferably 2 or more, and more preferably 3 or more. １０ The number of carbon atoms in is preferably 29 or less, more preferably 23 or less. The metal atom of M includes alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred. M is H, a metal atom, or NR １１ ４ is preferred, and H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR １１ ４ is more preferred, and H, Na, K, Li or NH ４ is more preferred, Na, K or NH ４ is even more preferred, Na or NH ４ is particularly preferred, and NH ４ is most preferred.

[0392] Compound (α) includes R １２ -COOM (in the formula, R １２ is a linear or branched alkyl group, alkenyl group, alkylene group or alkenylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group, alkenyl group, alkylene group or alkenylene group having 3 or more carbon atoms which may have a substituent, and these may contain an ether bond. When the carbon number is 3 or more, it may contain a monovalent or divalent heterocycle or may form a ring. M is the same as above. ) are also included. Specifically, CH ３ - (CH ２ ) ｎ -COOM (wherein n is an integer of 2 to 28, and M is the same as above).

[0393] From the viewpoint of emulsion stability, the compound (α) may be one that does not contain a carbonyl group (excluding the carbonyl group in a carboxyl group). Examples of the hydrocarbon-containing surfactant that does not contain a carbonyl group include those represented by the following formula (A): R-COO-M (A) (wherein R is an alkyl group, an alkenyl group, an alkylene group, or an alkenylene group, which may contain an ether bond. M is H, a metal atom, NR １１ ４ , an imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent. １１ are the same or different and are H or an organic group having 1 to 10 carbon atoms. In the above formula (A), R is preferably an alkyl group or an alkenyl group (which may contain an ether group). The alkyl group or alkenyl group in R may be linear or branched. The number of carbon atoms in R is not limited, but is, for example, 2 to 29.

[0394] When the alkyl group is linear, the number of carbon atoms in R is preferably 3 to 29, and more preferably 5 to 23. When the alkyl group is branched, the number of carbon atoms in R is preferably 5 to 35, and more preferably 11 to 23. When the alkenyl group is linear, the number of carbon atoms in R is preferably 2 to 29, and more preferably 9 to 23. When the alkenyl group is branched, the number of carbon atoms in R is preferably 2 to 29, and more preferably 9 to 23.

[0395] Examples of the alkyl group and alkenyl group include a methyl group, an ethyl group, an isobutyl group, a t-butyl group, and a vinyl group.

[0396] Further, examples of the anionic hydrocarbon surfactant include carboxylic acid hydrocarbon surfactants. Examples of the carboxylic acid hydrocarbon surfactants include butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, (9,12,15)-linolenic acid, (6,9,12)linolenic acid, eleostearic acid, arachidic acid, 8,11-eicosadienoic acid, mead acid, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, crotonic acid, myristic acid, hydroxybenzoic ... Examples of suitable salts include oleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, α-eleostearic acid, β-eleostearic acid, mead acid, dihomo-γ-linolenic acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, bosseopentaenoic acid, eicosapentaenoic acid, osbondo acid, sardine acid, tetracosapentaenoic acid, docosahexaenoic acid, herring acid, and salts thereof. Particularly preferred are at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecylic acid, palmitic acid, and salts thereof. The salts include those in which the hydrogen atom of the carboxyl group is bonded to a metal atom of the formula M, NR １１ ４ Examples of the compound include, but are not limited to, imidazolium which may have a substituent, pyridinium which may have a substituent, and phosphonium which may have a substituent.

[0397] Furthermore, examples of anionic hydrocarbon surfactants that can be used include those described in International Publication Nos. 2013 / 146950 and 2013 / 146947. Examples include those having a saturated or unsaturated aliphatic chain containing 6 to 40 carbon atoms, preferably 8 to 20 carbon atoms, and more preferably 9 to 13 carbon atoms. The saturated or unsaturated aliphatic chain may be either a linear or branched chain, or may have a cyclic structure. The hydrocarbon may be aromatic or may have an aromatic group. The hydrocarbon may have a heteroatom such as oxygen, nitrogen, or sulfur.

[0398] Examples of anionic hydrocarbon surfactants include alkyl sulfonates, alkyl sulfates, alkylaryl sulfates, and salts thereof; aliphatic (carboxylic) acids and salts thereof; alkyl phosphates, alkylaryl phosphates, and salts thereof; and among these, alkyl sulfonates, alkyl sulfates, aliphatic carboxylic acids, and salts thereof are preferred.

[0399] Preferred alkyl sulfates or salts thereof include ammonium lauryl sulfate and sodium lauryl sulfate. Preferred aliphatic carboxylic acids or salts thereof include succinic acid, decanoic acid, undecanoic acid, undecenoic acid, lauric acid, hydrododecanoic acid, and salts thereof.

[0400] The content of the anionic hydrocarbon surfactant in the first coating composition of the present disclosure is preferably 10 ppm to 5000 ppm relative to the fluororesin, although this will depend on the types of other compounding ingredients. The lower limit of the content of the anionic hydrocarbon surfactant is more preferably 50 ppm or more, even more preferably 100 ppm or more, more preferably 4000 ppm or less, and even more preferably 3000 ppm or less, relative to the fluororesin. By keeping the content of the anionic hydrocarbon surfactant within the above range, it is possible to appropriately adjust the viscosity of the coating composition and improve the miscibility of pigments, fillers, etc., while suppressing excessive foaming.

[0401] In the second coating composition and the third coating composition of the present disclosure, the content of the anionic hydrocarbon surfactant in the coating composition is preferably 10 ppm to 5000 ppm relative to PTFE, depending on the types of other compounding ingredients. The lower limit of the content of the anionic hydrocarbon surfactant is more preferably 50 ppm or more, even more preferably 100 ppm or more, more preferably 4000 ppm or less, and even more preferably 3000 ppm or less relative to PTFE. By keeping the content of the anionic hydrocarbon surfactant within the above range, it is possible to appropriately adjust the viscosity of the coating composition and improve the miscibility of pigments, fillers, etc., while suppressing excessive foaming.

[0402] The third coating composition of the present disclosure is substantially free of fluorine-containing compounds having hydrophilic groups (excluding the monomer (I) and polymer (I) represented by general formula (I)). The first coating composition and the second coating composition of the present disclosure may contain fluorine-containing compounds having hydrophilic groups, but preferably are substantially free of fluorine-containing compounds having hydrophilic groups (excluding the monomer (I) and polymer (I) represented by general formula (I)).

[0403] In the present disclosure, "substantially free of fluorine-containing compounds having hydrophilic groups" means that the content of fluorine-containing compounds having hydrophilic groups in the coating composition is 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 25 ppb by mass or less, still more preferably 10 ppb by mass or less, particularly preferably 1 ppb by mass or less, and most preferably the amount of fluorine-containing compounds having hydrophilic groups is below the detection limit when measured by liquid chromatography-mass spectrometry (LC / MS).

[0404] In another embodiment of the coating composition of the present disclosure, the coating composition is substantially free of a fluorine-containing surfactant.

[0405] In the present disclosure, "substantially free of fluorine-containing surfactant" means that the content of fluorine-containing surfactant in the coating composition is 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, still more preferably 1 ppb by mass or less, and particularly preferably below the detection limit of the fluorine-containing surfactant as measured by liquid chromatography-mass spectrometry (LC / MS).

[0406] In another embodiment of the coating composition of the present disclosure, the coating composition is substantially free of anionic fluorine-containing surfactants.

[0407] In the present disclosure, "substantially free of anionic fluorine-containing surfactant" means that the content of anionic fluorine-containing surfactant in the coating composition is 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, still more preferably 1 ppb by mass or less, and particularly preferably below the detection limit when measured by liquid chromatography-mass spectrometry (LC / MS).

[0408] In another embodiment of the coating composition of the present disclosure, the coating composition is substantially free of fluorine-containing anionic surfactants in which the molecular weight of the anionic moiety is 800 or less.

[0409] In the present disclosure, "substantially free of fluorine-containing anionic surfactants whose anionic moiety has a molecular weight of 800 or less" means that the content of fluorine-containing anionic surfactants whose anionic moiety has a molecular weight of 800 or less in the coating composition is 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, still more preferably 1 ppb by mass or less, and particularly preferably below the detection limit when measured by liquid chromatography-mass spectrometry (LC / MS).

[0410] The content of the fluorine-containing compound having a hydrophilic group can be quantified by a known method. For example, it can be measured by adding methanol to the composition, extracting, and analyzing the obtained extract by LC / MS. To further improve the extraction efficiency, treatments such as Soxhlet extraction and ultrasonic treatment may be performed. Molecular weight information is extracted from the obtained LC / MS spectrum, and its agreement with the structural formula of the candidate fluorine-containing compound having a hydrophilic group is confirmed. Thereafter, aqueous solutions containing five or more levels of the confirmed fluorine-containing compound having a hydrophilic group are prepared, and LC / MS analysis is performed on the aqueous solutions containing each level. The relationship between the content and the area relative to the content is plotted, and a calibration curve is drawn. Then, using the calibration curve, the area of ​​the LC / MS chromatogram of the fluorine-containing compound having a hydrophilic group in the extract can be converted to the content of the fluorine-containing compound having a hydrophilic group.

[0411] Examples of the fluorine-containing compound containing a hydrophilic group include a fluorine-containing surfactant, a fluorine-containing telomer containing a hydrophilic group, a fluorine-containing oligomer containing a hydrophilic group, a perfluoropolyether carboxylic acid, and a perfluoropolyether sulfonic acid.

[0412] Examples of the hydrophilic group include -NH ２ , -PO ３ M, -P(O)(OM) ２ , -OPO ３ M, -OP(O)(OM) ２ , -SO ３ M, -OSO ３ M, -COOM (in each formula, M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium, R ７ are H or organic groups and may be the same or different. Any two of them may be bonded to each other to form a ring.) Among the above hydrophilic groups, -SO ３ M or -COOM is preferred.

[0413] Examples of the fluorine-containing surfactant include anionic fluorine-containing surfactants, etc. The anionic fluorine-containing surfactant may be, for example, a surfactant containing fluorine atoms and having a total carbon number of 20 or less excluding the anionic group.

[0414] The fluorine-containing surfactant may be a surfactant containing fluorine, the molecular weight of which in the anionic moiety is 800 or less. The "anionic moiety" means the part of the fluorine-containing surfactant excluding the cation. For example, F(CF) represented by the formula (I) described below may be used. ２ ) ｎ１ In the case of COOM, "F(CF ２ ) ｎ１ This is the "COO" part.

[0415] The fluorine-containing surfactant also includes a fluorine-containing surfactant having a Log POW of 3.5 or less. The Log POW is the partition coefficient between 1-octanol and water, and is expressed as Log P [where P represents the ratio of the fluorine-containing surfactant concentration in octanol to the fluorine-containing surfactant concentration in water when a 1:1 octanol / water mixture containing the fluorine-containing surfactant undergoes phase separation]. The Log POW can be measured using a column: TOSOH ODS-120T column (φ4.6 mm×250 mm, manufactured by Tosoh Corporation), an eluent: acetonitrile / 0.6% by mass HClO ４ HPLC is performed on standard substances (heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid) with known octanol / water partition coefficients under conditions of water=1 / 1 (vol / vol %), flow rate: 1.0 ml / min, sample amount: 300 μL, column temperature: 40°C, and detection light: UV 210 nm. A calibration curve is prepared between each elution time and the known octanol / water partition coefficient, and the elution time is calculated from the HPLC elution time of the sample solution based on this calibration curve.

[0416] Specific examples of the fluorine-containing surfactants include those described in U.S. Patent Application Publication No. 2007 / 0015864, U.S. Patent Application Publication No. 2007 / 0015865, U.S. Patent Application Publication No. 2007 / 0015866, U.S. Patent Application Publication No. 2007 / 0276103, U.S. Patent Application Publication No. 2007 / 0117914, U.S. Patent Application Publication No. 2007 / 142541, U.S. Patent Application Publication No. 2008 / 0015319, and U.S. Patent No. 3,250,808. , U.S. Patent No. 3,271,341, JP 2003-119204 A, WO 2005 / 042593, WO 2008 / 060461, WO 2007 / 046377, WO 2007 / 119526, WO 2007 / 046482, WO 2007 / 046345, U.S. Patent Application Publication No. 2014 / 0228531, WO 2013 / 189824, and those described in WO 2013 / 189826, and the like.

[0417] The anionic fluorine-containing surfactant may be a surfactant represented by the general formula (N ０ ): X ｎ０ -Rf ｎ０ -Y ０ (N ０ ) (wherein, X ｎ０ is H, Cl or F. ｎ０ is a linear, branched or cyclic alkylene group having 3 to 20 carbon atoms, in which some or all of the H atoms have been substituted with F, and the alkylene group may contain one or more ether bonds, and some of the H atoms may have been substituted with Cl. ０ is an anionic group.

[0418] Y ０ The anionic group is -COOM, -SO ２ M or -SO ３ M, -COOM or -SO ３ M. M may be H, a metal atom, NR ７ ４, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group. The metal atom includes alkali metals (Group 1), alkaline earth metals (Group 2), etc., such as Na, K, or Li. ７ As the group, H or C １－１０ and may be an organic group of the formula: １－４ and may be an organic group of the formula: １－４ M may be H, a metal atom, or an alkyl group of the formula NR ７ ４ may be H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR ７ ４ may be H, Na, K, Li or NH ４ The above Rf ｎ０ may be one in which 50% or more of H is substituted with fluorine.

[0419] General formula (N ０ The compound represented by the general formula (N １ ): X ｎ０ -(CF ２ ) ｍ１ -Y ０ (N １ ) (wherein, X ｎ０ is H, Cl, and F, m1 is an integer from 3 to 15, and Y ０ is as defined above), a compound represented by the general formula (N ２ ): Rf ｎ１ -O-(CF(CF ３ )CF ２ O) ｍ２ CFX ｎ１ -Y ０ (N ２ ) (wherein, Rf ｎ１ is a perfluoroalkyl group having 1 to 5 carbon atoms, m2 is an integer of 0 to 3, and X ｎ１ is F or CF ３ and Y ０ is as defined above), a compound represented by the general formula (N ３ ): Rf ｎ２(CH ２ ) ｍ３ -(Rf ｎ３ ) ｑ -Y ０ (N ３ ) (wherein, Rf ｎ２ is a partially or fully fluorinated alkyl group having 1 to 13 carbon atoms which may contain an ether bond, m3 is an integer of 1 to 3, and Rf ｎ３ is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, q is 0 or 1, and Y ０ is as defined above), a compound represented by the general formula (N ４ ): Rf ｎ４ -O-(CY ｎ１ Y ｎ２ ) ｐ CF ２ -Y ０ (N ４ ) (wherein, Rf ｎ４ is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms, which may contain an ether bond and / or a chlorine atom; Y ｎ１ and Y ｎ２ are the same or different and are H or F, p is 0 or 1, and Y ０ is as defined above), a compound represented by the general formula (N ５ ): (In the formula, X ｎ２ , X ｎ３ and X ｎ４ Rf may be the same or different and are H, F, or a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, which may contain an ether linkage. ｎ５ is a linear or branched partially or fully fluorinated alkylene group having 1 to 3 carbon atoms, which may contain an ether bond; L is a linking group; Y ０ is as defined above, where X ｎ２ , X ｎ３ , X ｎ４ and Rf ｎ５ wherein the total number of carbon atoms is 18 or less.

[0420] General formula (N ０More specifically, the compounds represented by the general formula (I) include perfluorocarboxylic acids (I), ω-H perfluorocarboxylic acids (II), general formula (III), perfluoropolyether carboxylic acids (III), general formula (IV), perfluoroalkyl alkylene carboxylic acids (IV), general formula (V), perfluoroalkoxy fluorocarboxylic acids (V), general formula (VI), perfluoroalkyl sulfonic acids (VI), general formula (VII), ω-H perfluoro sulfonic acids (VII), general formula (VIII), perfluoroalkyl alkylene sulfonic acids (VIII), general formula (IX), alkyl alkylene carboxylic acids (IX), general formula (X), fluorocarboxylic acids (X), general formula (XI), alkoxy fluoro sulfonic acids (XI), general formula (XII), and compounds represented by the following general formula (XIII).

[0421] The perfluorocarboxylic acid (I) is represented by the general formula (I): F(CF ２ ) ｎ１ COOM (I) (wherein n1 is an integer of 3 to 14, and M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0422] The ω-H perfluorocarboxylic acid (II) is represented by the general formula (II): H(CF ２ ) ｎ２ COOM (II) (wherein n2 is an integer of 4 to 15, and M is as defined above).

[0423] The perfluoropolyether carboxylic acid (III) is represented by the general formula (III): Rf １ -O-(CF(CF ３ )CF ２ O) ｎ３ CF (CF ３) COOM (III) (wherein, Rf １ is a perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer of 0 to 3, and M is as defined above.

[0424] The perfluoroalkyl alkylene carboxylic acid (IV) is represented by the general formula (IV): Rf ２ (CH ２ ) ｎ４ Rf ３ COOM (IV) (wherein, Rf ２ is a perfluoroalkyl group having 1 to 5 carbon atoms, and Rf ３ is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, n4 is an integer of 1 to 3, and M is as defined above.

[0425] The alkoxyfluorocarboxylic acid (V) is represented by the general formula (V): Rf ４ -O-CY １ Y ２ CF ２ -COOM (V) (wherein, Rf ４ is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms, which may contain an ether bond and / or a chlorine atom; Y １ and Y ２ are the same or different and are H or F, and M is as defined above.

[0426] The perfluoroalkylsulfonic acid (VI) is represented by the general formula (VI): F(CF ２ ) ｎ５ SO ３ M (VI) (wherein n5 is an integer of 3 to 14, and M is as defined above).

[0427] The ω-H perfluorosulfonic acid (VII) is represented by the general formula (VII): H(CF ２ ) ｎ６ SO ３ M (VII) (wherein n6 is an integer of 4 to 14, and M is as defined above).

[0428] The perfluoroalkyl alkylene sulfonic acid (VIII) is represented by the general formula (VIII): Rf ５ (CH ２ ) ｎ７ SO ３ M (VIII) (wherein, Rf ５ is a perfluoroalkyl group having 1 to 13 carbon atoms, n7 is an integer of 1 to 3, and M is as defined above.

[0429] The alkyl alkylene carboxylic acid (IX) is represented by the general formula (IX): ６ (CH ２ ) ｎ８ COOM (IX) (wherein, Rf ６ is a linear or branched partially or fully fluorinated alkyl group having 1 to 13 carbon atoms which may contain an ether bond, n8 is an integer from 1 to 3, and M is as defined above.

[0430] The fluorocarboxylic acid (X) is represented by the general formula (X): Rf ７ -O-Rf ８ -O-CF ２ -COOM (X) (wherein, Rf ７ is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, which may contain an ether bond and / or a chlorine atom, and Rf ８ is a linear or branched, partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and M is as defined above.

[0431] The alkoxyfluorosulfonic acid (XI) is represented by the general formula (XI): Rf ９ -O-CY １ Y ２ CF ２ -SO ３ M (XI) (wherein, Rf ９ is a linear or branched alkyl group having 1 to 12 carbon atoms, which may contain an ether bond, and which may contain chlorine, and which is partially or completely fluorinated; Y １ and Y２ are the same or different and are H or F, and M is as defined above.

[0432] The compound (XII) is represented by the general formula (XII): (In the formula, X １ , X ２ and X ３ Rf may be the same or different and are H, F and linear or branched partially or fully fluorinated alkyl groups having 1 to 6 carbon atoms, which may contain ether bonds; １０ is a perfluoroalkylene group having 1 to 3 carbon atoms, L is a linking group, and Y ０ is an anionic group. ０ is -COOM, -SO ２ M or -SO ３ M, and -SO ３ M or COOM (wherein M is as defined above). Examples of L include a single bond and a partially or fully fluorinated alkylene group having 1 to 10 carbon atoms which may contain an ether bond.

[0433] The compound (XIII) has the following general formula (XIII): １１ -O-(CF ２ CF (CF ３ ) O) ｎ９ (CF ２ O) ｎ１０ CF ２ COOM (XIII) (wherein, Rf １１ is a fluoroalkyl group containing chlorine and having 1 to 5 carbon atoms, n9 is an integer of 0 to 3, n10 is an integer of 0 to 3, and M is as defined above. ２ ClO(CF ２ CF (CF ３ ) O) ｎ９ (CF ２ O) ｎ１０ CF ２ COONH ４ (a mixture having an average molecular weight of 750, wherein n9 and n10 are defined above).

[0434] Thus, examples of the anionic fluorine-containing surfactant include carboxylic acid surfactants and sulfonic acid surfactants.

[0435] The fluorine-containing surfactant may be one type of fluorine-containing surfactant or a mixture containing two or more types of fluorine-containing surfactants.

[0436] Examples of the fluorine-containing surfactant include compounds represented by the following formula: The fluorine-containing surfactant may be a mixture of these compounds. In one embodiment of the coating composition of the present disclosure, the coating composition is substantially free of a compound represented by the following formula: H(CF ２ ) ７ COOM, F(CF ２ ) ７ COOM, F(CF ２ ) ５ COOM, H(CF ２ ) ６ COOM, C.F. ３ O (CF ２ ) ３ OCHFCF ２ COOM, C ３ F ７ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ３ CF ２ CF ２ OCF (CF ３ ) COOM, C.F. ３ CF ２ OCF ２ CF ２ OCF ２ COOM, C ２ F ５ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ３ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ２ ClCF ２ CF ２ OCF (CF ３ )CF２ OCF ２ COOM, C.F. ２ ClCF ２ CF ２ OCF ２ CF (CF ３ ) OCF ２ COOM, C.F. ２ ClCF(CF ３ ) OCF (CF ３ )CF ２ OCF ２ COOM, C.F. ２ ClCF(CF ３ ) OCF ２ CF (CF ３ ) OCF ２ COOM, (In each formula, M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0437] In the present disclosure, "substantially free of compounds represented by the above formula" means that the content of compounds represented by the above formula in the coating composition is 10 ppm by mass or less in total, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, still more preferably 1 ppb by mass or less, and particularly preferably below the detection limit when measured by liquid chromatography-mass spectrometry (LC / MS).

[0438] <Film-forming agent> In one embodiment of the coating composition of the present disclosure, a film-forming agent is contained. When a film-forming agent is contained, the coating composition can suppress the occurrence of cracks when the resulting coating film is dried, and the coating composition has excellent workability.

[0439] Examples of the film-forming agent include acrylic resins such as depolymerizable acrylic resins, urethane resins, polyethylene glycol, and polypropylene glycol.

[0440] When the coating composition of the present disclosure is applied, dried, and then baked, the depolymerizable acrylic resin gradually decomposes while maintaining its binding effect on the fluororesin, thereby preventing the occurrence of cracks.

[0441] In one embodiment of the composition of the present disclosure, a depolymerizable acrylic resin is contained in addition to PTFE. The depolymerizable acrylic resin preferably remains up to the temperature at which PTFE begins to melt (melting temperature), even if depolymerization begins below the melting point of PTFE, and decomposes and volatilizes at the baking (processing) temperature. For example, at the melting temperature of PTFE (usually 240-345°C), 5% or more, particularly 10% or more, at least 50%, and preferably at least 20%, remain, but at the baking (processing) temperature (usually a temperature above the melting temperature of PTFE and up to 415°C, preferably 360-400°C), only 10% or less, particularly 5% or less remain, and essentially none remain at the completion of baking. From this perspective, the depolymerization (decomposition) temperature of the depolymerizable acrylic resin is preferably about 200°C or higher but lower than the baking (processing) temperature. In particular, regardless of the type of resin, a depolymerizable acrylic resin that remains at about 25 to 50% in the temperature range of 300 to 320°C and at about 20 to 10% in the temperature range of 330 to 345°C is suitable in terms of the balance between the effect of preventing shrinkage cracking and the effect of preventing discoloration, and any depolymerizable acrylic resin that satisfies this condition can be used.

[0442] As described in "Polym. Eng. Soi., Vol. 6, p. 273 (1966)," "Plast. Massy., Vol. 75, p. 48 (1971)," and "Deterioration of Polymer Materials," Corona Publishing, p. 144 (1958), the more branches there are in the polymer chain, the weaker the C-C bond and C-H bond become, and the easier it is to undergo oxidative decomposition and depolymerization. Examples of depolymerizable acrylic resins include methacrylate resins, and specific examples thereof include those represented by the formula (5): CH ２ =C(CH ３)COOR (5) (wherein R is an alkyl or hydroxyalkyl group having 1 to 5 carbon atoms) is preferred. Specific examples of the methacrylate monomer that are preferably used include methyl methacrylate, ethyl methacrylate, propyl methacrylate, dimethylpropyl methacrylate, butyl methacrylate, and pentyl methacrylate. Among these, depolymerizable acrylic resins that use butyl methacrylate as a monomer are preferred because of their low glass transition temperature and good depolymerizability (decomposability).

[0443] Furthermore, there is no problem if a stable emulsion can be formed using a homopolymer, but from the viewpoint of stabilizing the emulsion, a monomer having a carboxyl group or a hydroxyl group may be used as a comonomer as appropriate.

[0444] The depolymerizable acrylic resin can be used as fine particles (depolymerizable acrylic resin emulsion) produced by a method such as emulsion polymerization, and the average particle size is preferably 0.1 to 100 μm, particularly 0.2 to 1 μm. Particles with an average particle size of less than 0.1 μm tend to easily cause mud cracking, while particles with an average particle size of more than 100 μm tend to make coating difficult.

[0445] In the first coating composition of the present disclosure, the content of the depolymerizable acrylic resin is preferably 5 to 25 parts, more preferably 7 to 20 parts, and even more preferably 10 to 15 parts per 100 parts of the fluororesin, from the viewpoints of film-forming properties and prevention of discoloration of the coating film.

[0446] In the second and third coating compositions of the present disclosure, the content of the depolymerizable acrylic resin is preferably 5 to 25 parts, more preferably 7 to 20 parts, and even more preferably 10 to 15 parts per 100 parts of PTFE, from the viewpoints of film-forming properties and prevention of discoloration of the coating film.

[0447] The depolymerizable acrylic resin is preferably mixed with the other ingredients in the form of an emulsion.

[0448] <Binder Resin> In one embodiment of the coating composition of the present disclosure, a binder resin is contained. When a binder resin is contained, the coating composition can provide a coating film with excellent adhesion to the substrate. The binder resin has the effect of improving the coating film hardness and gloss of the resulting coating film.

[0449] Examples of binder resins include polyamideimide (PAI), polyimide (PI), polyethersulfone (PES), polyarylene sulfide (PAS), polyetherimide, polyetheretherketone, aromatic polyester, etc. The binder resins may be used alone or in combination of two or more.

[0450] PAI is a resin made of a polymer having an amide bond and an imide bond in its molecular structure. There are no particular limitations on the PAI. Examples of PAI include, but are not limited to, resins made of high-molecular-weight polymers obtained by various reactions, such as the reaction of an aromatic diamine having an amide bond in the molecule with an aromatic tetracarboxylic acid such as pyromellitic acid; the reaction of an aromatic tricarboxylic acid such as trimellitic anhydride with a diamine such as 4,4-diaminophenyl ether or a diisocyanate such as diphenylmethane diisocyanate; and the reaction of a dibasic acid having an aromatic imide ring in the molecule with a diamine. As PAI, those made of a polymer having an aromatic ring in the main chain are preferred because of their excellent heat resistance.

[0451] PI is a resin made of a polymer having an imide bond in its molecular structure. There are no particular limitations on the PI, but examples include resins made of high-molecular-weight polymers obtained by the reaction of aromatic tetracarboxylic anhydrides such as pyromellitic anhydride. As PI, those made of polymers having an aromatic ring in the main chain are preferred because of their excellent heat resistance.

[0452] PES is represented by the following general formula:

[0453]

[0454] The PES is not particularly limited, but examples thereof include a resin made of a polymer obtained by polycondensation of dichlorodiphenyl sulfone and bisphenol.

[0455] PAS is a resin made of a polymer having a repeating unit represented by the general formula -[Ar-S]- (wherein Ar represents an arylene group). The PAS is not particularly limited, but examples thereof include polyphenylene sulfide (PPS).

[0456] As the binder resin, at least one selected from the group consisting of PAI, PI, PES, and PPS is preferred, with PAI being more preferred, as it can provide a coating film with even better adhesion to the substrate. Furthermore, PES is preferred as the binder resin, as it can suppress coloration during baking and increase the degree of freedom in color tone of the coating film. Using a combination of PAI and PES as the binder resin is also a preferred embodiment.

[0457] In the coating composition of the present disclosure, the content of the binder resin is preferably 5% by mass or more, more preferably 8% by mass or more, and preferably 15% by mass or less, more preferably 12% by mass or less, based on the coating composition. When the content of the binder resin is within the above range, a coating film with even better adhesion to the substrate can be obtained.

[0458] In the first coating composition of the present disclosure, the mass ratio of the fluororesin to the binder resin (fluororesin / binder resin) is preferably 90 / 10 to 50 / 50, more preferably 85 / 15 to 60 / 40, and even more preferably 80 / 20 to 70 / 30. When the mass ratio of the fluororesin to the binder resin is within the above range, a coating film with even better adhesion to the substrate can be obtained.

[0459] In the second and third coating compositions of the present disclosure, the mass ratio of PTFE to binder resin (PTFE / binder resin) is preferably 90 / 10 to 50 / 50, more preferably 85 / 15 to 60 / 40, and even more preferably 80 / 20 to 70 / 30. When the mass ratio of PTFE to binder resin is within the above range, a coating film with even better adhesion to the substrate can be obtained.

[0460] The coating composition of the present disclosure may contain other components, such as preservatives, water-soluble polymer compounds, pigments, fillers, antifoaming agents, drying agents, thickeners, organic solvents, leveling agents, anti-cracking agents, dispersants, antifreezing agents, solid lubricants, anti-settling agents, moisture absorbers, surface conditioners, thixotropy-imparting agents, viscosity modifiers, anti-gelling agents, UV absorbers, HALS (light stabilizers), matting agents, plasticizers, anti-color separation agents, anti-skinning agents, anti-scratch agents, rust inhibitors, mildew inhibitors, antibacterial agents, antioxidants, flame retardants, anti-sagging agents, antistatic agents, silane coupling agents, various reinforcing agents, various extenders, conductive fillers, and colloidal silica.

[0461] The paint composition of the present disclosure contains a preservative, which makes it possible to inhibit spoilage of the paint composition and bacterial growth even when the paint composition is stored for a long period of time.

[0462] Examples of preservatives include isothiazolones, azoles, pronopol, chlorothalonil, methylsulfonyltetrachloropyrrolidin, carbentazim, fluorophorbet, sodium diacetate, and diiodomethyl-paratolylsulfone.

[0463] The content of the preservative in the first coating composition of the present disclosure is preferably 0.01 to 0.5 mass % relative to the fluororesin, and more preferably 0.05 to 0.2 mass %. The content of the preservative in the second coating composition and the third coating composition of the present disclosure is preferably 0.01 to 0.5 mass % relative to the PTFE, and more preferably 0.05 to 0.2 mass %.

[0464] Examples of the water-soluble polymer compound include methyl cellulose, alumina sol, polyvinyl alcohol, carboxylated vinyl polymer, polyethylene oxide (dispersion stabilizer), polyethylene glycol (dispersion stabilizer), polyvinylpyrrolidone (dispersion stabilizer), phenol resin, urea resin, epoxy resin, melamine resin, polyester resin, polyether resin, acrylic silicone resin, silicone resin, silicone polyester resin, and polyurethane resin.

[0465] As the pigment, various conventionally known pigments can be used, such as titanium oxide, carbon black, red iron oxide, extender pigments, etc. In the coating composition of the present disclosure, the content of the pigment is preferably 0.1 to 20.0% by mass, and more preferably 1 to 10% by mass, relative to the coating composition.

[0466] Examples of the filler include inorganic fillers, diamond, fluorinated diamond, and carbon black.

[0467] Examples of inorganic fillers include pigments, mica particles, mica particles coated with pigments, titanium-coated mica, inorganic nitrides, carbides, borides and oxides of zirconium, tantalum, titanium, tungsten, silicon, aluminum or beryllium (specifically, aluminum oxide, silicon carbide, zirconium oxide, zirconium carbide, etc.), metal flakes, metal powder, clay, talc, tourmaline, jade, germanium, corundum, silica stone, chrysoberyl, topaz, beryl, garnet, quartz, garnet, barium sulfate, glass, and the like.

[0468] The inorganic filler provides the function of improving abrasion resistance, and mica is preferred in terms of aesthetic appearance. The particle size of the mica particles is 10 to 100 μm, preferably 15 to 50 μm. If the particle size is less than 10 μm, the abrasion resistance and brilliance tend to decrease, and if it exceeds 100 μm, the non-stickiness tends to decrease. The mica particles coated with a pigment are, for example, TiO ２ Fe ２ O ３ The pigment can be obtained by adhering the above pigment to the mica particles by a sintering deposition method or the like.

[0469] Examples of metal flakes include flakes of titanium, zirconium, aluminum, zinc, antimony, tin, iron, nickel, etc., but titanium and zirconium are preferred from the viewpoint of rust resistance. The size of the flakes can be within the range of sizes normally used in paints.

[0470] Examples of metal powders include powders of gold, silver, copper, platinum, and stainless steel.

[0471] Various aqueous defoaming agents can be used, including, for example, lower alcohols such as methanol, ethanol, butanol, etc.; higher alcohols such as amyl alcohol, polypropylene glycol and derivatives thereof; oils and fats such as oleic acid, tall oil, mineral oil, soap, etc.; surfactants such as sorbitan fatty acid esters, polyethylene glycol fatty acid esters, Pluronic-type nonionic surfactants, etc.; and silicone surfactants such as siloxanes and silicone resins, which can be used alone or in combination. Typical commercially available defoaming agents include the B-series (manufactured by Asahi Denka Kogyo Co., Ltd.) such as Adekanate B and Adekanate B1068; the SN Defoamer series (manufactured by Formaster DL, Nopco NXZ, SN Defoamer 113, 325, 308, 368, etc.); Dehydran 1293 and Dehydran 1513 (manufactured by San Nopco Ltd.); Fronon SB-110N, SB-210, 510, 551, Aqualene 800, 805. , Aqualene 1488 (manufactured by Kyoeisha Chemical Co., Ltd.); Surfynol 104E, 440 (acetylene-based defoamers manufactured by Air Products Co., Ltd.); KS-607A (manufactured by Shin-Etsu Chemical Co., Ltd.); FS Antifoam (manufactured by Dow Corning Corporation); BYK-020, 031, 073, W (manufactured by BYK-Chemie); Dehydran 981 (manufactured by Henkel Hakusui Chemical Co., Ltd.); Epan-410, 710, 720 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); Tego Foamex series (manufactured by Tego Goldschmidt); Foamrex-747, TY-10, EP series (manufactured by Nicca Chemical Co., Ltd.). The content of the defoamer in the coating composition is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass.

[0472] An example of the desiccant is cobalt oxide.

[0473] Examples of thickeners include methyl cellulose, polyvinyl alcohol, carboxylated vinyl polymers, etc. In the coating composition of the present disclosure, the content of the thickener is preferably 0.1 to 20.0% by mass, and more preferably 0.5 to 10% by mass.

[0474] The organic solvent is preferably a high-boiling polyhydric alcohol, which can prevent mud cracks from occurring when the coating composition of the present disclosure is applied and then dried.

[0475] A high-boiling polyhydric alcohol (hereinafter referred to as "polyhydric alcohol") has two or more hydroxyl groups and a boiling point of 100°C or higher. Polyhydric alcohols containing nitrogen atoms are not preferred because they cause discoloration due to thermal decomposition during baking. Preferably, the boiling point is at or above the drying temperature of the coating composition, more preferably at or above 150°C, and particularly at or above 200°C. The preferred number of hydroxyl groups in a polyhydric alcohol is 2 to 3. Substances with one or no hydroxyl group and a boiling point of 100°C or higher have poor hydrophilicity, making uniform mixing difficult. Many polyhydric alcohols with four or more hydroxyl groups are solid at room temperature, making it difficult to expect mud crack prevention effects.

[0476] The polyhydric alcohol must be completely evaporated or decomposed and vaporized by heating during the baking process described below. Therefore, it is preferable that the boiling point or thermal decomposition temperature is equal to or lower than the melting point of the fluororesin or PTFE contained in the coating composition, preferably 340°C or lower.

[0477] Suitable polyhydric alcohols include, for example, one or more of ethylene glycol (boiling point: 198°C), 1,2-propanediol (boiling point: 188°C), 1,3-propanediol (boiling point: 214°C), 1,2-butanediol (boiling point: 190°C), 1,3-butanediol (boiling point: 208°C), 1,4-butanediol (boiling point: 229°C), 1,5-pentanediol (boiling point: 242°C), 2-butene-1,4-diol (boiling point: 235°C), glycerin (boiling point: 290°C), 2-ethyl-2-hydroxymethyl-1,3-propanediol (boiling point: 295°C), and 1,2,6-hexanetriol (boiling point: 178°C under 5 mmHg pressure). Of these, glycerin is preferred.

[0478] In the first coating composition of the present disclosure, the content of the polyhydric alcohol is generally 5 to 18 mass%, preferably 7 to 15 mass%, and particularly preferably 7 to 12 mass%, relative to the fluororesin. In the second coating composition and the third coating composition of the present disclosure, the content of the polyhydric alcohol is generally 5 to 18 mass%, preferably 7 to 15 mass%, and particularly preferably 7 to 12 mass%, relative to the PTFE. By keeping the polyhydric alcohol content within the above range, it is possible to prevent the occurrence of mud cracks while preventing discoloration of the resulting coating film.

[0479] If necessary, organic solvents other than the high-boiling polyhydric alcohols may be blended within a range that does not impair the effects of the present disclosure. Examples of such organic solvents include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents having 9 to 11 carbon atoms.

[0480] <Method for producing coating composition> The first coating composition of the present disclosure can be suitably produced, for example, by a production method including a step of polymerizing a fluoromonomer in an aqueous medium in the presence of polymer (I) to obtain a polymerization dispersion containing a fluororesin, polymer (I), and an aqueous medium, and a step of concentrating the polymerization dispersion by phase separation concentration to obtain a concentrated composition.

[0481] As a method for polymerizing a fluoromonomer in an aqueous medium in the presence of polymer (I), a conventionally known method can be adopted, for example, the method described in WO 2019 / 168183 or WO 2020 / 218620 can be adopted.

[0482] The polymerization is preferably carried out in the absence of a fluorine-containing surfactant. In the present disclosure, "substantially in the absence of a fluorine-containing surfactant" means that the fluorine-containing surfactant is present at a concentration of 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, and still more preferably 1 ppb by mass or less, relative to the aqueous medium.

[0483] After obtaining a polymer dispersion containing a fluororesin, polymer (I), and an aqueous medium, the polymer dispersion is concentrated by phase separation concentration. By performing phase separation concentration, the content of polymer (I) in the coating composition of the present disclosure can be adjusted to the preferred range described above.

[0484] The concentration by phase separation can be carried out by heating a polymer dispersion containing a fluororesin, polymer (I), and an aqueous medium to cause phase separation into a fluororesin-free phase (supernatant phase) and a fluororesin-containing phase (concentrated phase), removing the fluororesin-free phase, and recovering the fluororesin-containing phase (concentrated phase).

[0485] Prior to the phase separation concentration, the polymer dispersion may be mixed with a nonionic surfactant to prepare a composition containing a fluororesin, polymer (I), a nonionic surfactant, and an aqueous medium, and the resulting composition may then be subjected to phase separation concentration. In this case, the phase separation concentration can be carried out by heating the composition to a temperature at least 10°C lower than the cloud point of the nonionic surfactant to cause phase separation into a supernatant phase and a concentrated phase, and recovering the concentrated phase to obtain a concentrated composition. The nonionic surfactant used in this case may be any of those described above, preferably at least one selected from the group consisting of nonionic surfactants represented by general formula (i) and nonionic surfactants represented by general formula (ii), more preferably nonionic surfactants represented by general formula (i). Furthermore, polyoxyethylene alkyl ethers are suitable as nonionic surfactants.

[0486] The recovered fluororesin-containing phase (concentrated phase) contains the fluororesin and the aqueous medium, as well as the polymer (I) in a content reduced from that before concentration.

[0487] The concentration by phase separation may be carried out by leaving the mixture at a temperature that is 10° C. lower than the cloud point of the nonionic surfactant or higher. Alternatively, the concentration by phase separation may be carried out by leaving the mixture at a temperature that is 10° C. higher than the cloud point or lower.

[0488] It is also preferable to repeatedly perform the phase separation concentration. The number of repetitions is not particularly limited, but is preferably 2 or more times, more preferably 3 or more times. The upper limit of the number of repetitions is not limited, but may be, for example, 10 or less times. By repeatedly performing the phase separation concentration, the content of polymer (I) can be further reduced.

[0489] When the phase separation concentration is performed two or more times, the first phase separation concentration is preferably performed by heating at a temperature at least 5°C lower than the cloud point of the nonionic surfactant and then allowing to stand, resulting in separation into an upper supernatant phase and a concentrated phase. The heating temperature is more preferably at least 3°C ​​lower than the cloud point, even more preferably at least the cloud point, and particularly preferably heating above the cloud point. The second or subsequent phase separation concentration is preferably performed by heating at a temperature at least 5°C lower than the cloud point of the nonionic surfactant and then allowing to stand, resulting in separation into an upper supernatant phase and a concentrated phase. The heating temperature is more preferably at least 3°C ​​lower than the cloud point, and particularly preferably heating to the cloud point.

[0490] After the phase separation concentration, the concentrated composition may be mixed with an anionic hydrocarbon surfactant. By adding an anionic surfactant to the concentrated composition, it is possible to appropriately adjust the viscosity of the coating composition and improve the compatibility with pigments, fillers, etc., even when the coating composition contains a large amount of fluororesin.

[0491] After the phase separation concentration, a nonionic surfactant may be further added to the concentrated composition and mixed. By further adding a nonionic surfactant to the concentrated composition, the viscosity of the coating composition can be appropriately adjusted and the miscibility of pigments, fillers, etc. can be improved, even when the coating composition contains a large amount of fluororesin. The nonionic surfactant used in this case can be any of those described above. Preferably, at least one selected from the group consisting of nonionic surfactants represented by general formula (i) and nonionic surfactants represented by general formula (ii) is used, with nonionic surfactants represented by general formula (i) being more preferred. Furthermore, polyoxyethylene alkyl ethers are suitable as nonionic surfactants.

[0492] A fluorine-containing compound having a hydrophilic group may be added to the polymer dispersion or the concentrated composition, but it is preferable not to add it to either of them.

[0493] The coating composition of the present disclosure can be produced by mixing the concentrated composition with components such as a film-forming agent, a binder resin, and other components that are added as needed. Alternatively, two or more aqueous dispersions may be produced by the above method and then mixed together. The method for mixing the components is not particularly limited, and any conventionally known method can be used. The order in which the components are mixed is also not particularly limited.

[0494] The second coating composition of the present disclosure can be suitably produced by a production method including the steps of: polymerizing TFE in an aqueous medium in the presence of polymer (I) to obtain a polymer dispersion containing PTFE, polymer (I), and an aqueous medium; and concentrating the polymer dispersion by performing phase separation concentration two or more times to obtain a concentrated composition. By such a production method, the second coating composition of the present disclosure, which has excellent aggregation suppression properties during stirring, can be obtained.

[0495] Regarding the step of obtaining a polymer dispersion, the above-mentioned step of polymerizing a fluoromonomer in an aqueous medium in the presence of the polymer (I) to obtain a polymer dispersion containing a fluororesin, the polymer (I) and an aqueous medium can have the same configuration as described above, except that TFE is used as the fluoromonomer and PTFE is obtained as the fluororesin.

[0496] The viscosity of the concentrated composition may be adjusted as necessary, for example, by mixing the concentrated composition with an anionic hydrocarbon surfactant, or by adding a nonionic surfactant to the concentrated composition and mixing them.

[0497] The third coating composition of the present disclosure can be suitably produced, for example, by a production method including the steps of: polymerizing TFE in an aqueous medium in the presence of a polymer (I) containing polymerized units (I) based on a monomer represented by general formula (I) to obtain a polymer dispersion containing PTFE, the polymer (I), and an aqueous medium; mixing the polymer dispersion with a nonionic surfactant to obtain a composition containing PTFE, the polymer (I), the nonionic surfactant, and the aqueous medium; concentrating the composition by phase separation concentration to obtain a concentrated composition; and adding an anionic hydrocarbon surfactant to the concentrated composition.

[0498] Regarding the step of obtaining a polymer dispersion, the above-mentioned step of polymerizing a fluoromonomer in an aqueous medium in the presence of the polymer (I) to obtain a polymer dispersion containing a fluororesin, the polymer (I) and an aqueous medium can have the same configuration as described above, except that TFE is used as the fluoromonomer and PTFE is obtained as the fluororesin.

[0499] As the anionic hydrocarbon surfactant, those described above as the anionic hydrocarbon surfactant that can be contained in the third coating composition of the present disclosure can be suitably used.

[0500] The mixing ratio of the concentrated composition and the anionic hydrocarbon surfactant is not particularly limited, but it is preferable to mix the concentrated composition and the anionic hydrocarbon surfactant in a ratio that results in a suitable content of the anionic hydrocarbon surfactant in the third coating composition of the present disclosure.

[0501] When producing the third coating composition of the present disclosure, it is preferred that the polymerization is carried out in the absence of a fluorine-containing surfactant, and that no fluorine-containing compound having a hydrophilic group is added to the polymer dispersion or concentrated composition.

[0502] The coating composition of the present disclosure can be applied, for example, as a coating material for products whose substrate surfaces require heat resistance, non-stickiness, slipperiness, etc. Examples of products provided with such a coating material include the coated articles described below.

[0503] <Coated Film> A coated film can be formed by applying the coating composition of the present disclosure onto a substrate. The present disclosure also relates to a coated film obtained by applying the coating composition of the present disclosure.

[0504] The coating film of the present disclosure is obtained by applying the coating composition of the present disclosure, and therefore contains a fluororesin or PTFE.

[0505] The coating film of the present disclosure may contain, as needed, the components described above as other components in the coating composition of the present disclosure, such as binder resins, pigments, and inorganic fillers.

[0506] The coating film preferably has a thickness of 1 to 100 μm, more preferably 10 μm or more, and more preferably 50 μm or less.

[0507] The method for obtaining the coating film of the present disclosure is not particularly limited, and examples include methods for applying the coating composition of the present disclosure to a substrate by spray coating, roll coating, coating with a doctor blade, dip (immersion) coating, impregnation coating, spin flow coating, curtain flow coating, etc. Of these, spray coating is preferred.

[0508] After applying the coating composition of the present disclosure to a substrate, the coating composition is preferably dried and baked. Drying is preferably carried out at a temperature of 80 to 200°C for 5 to 30 minutes, and baking is preferably carried out at a temperature of 300 to 400°C for 10 to 90 minutes.

[0509] Letters, drawings, etc. may be printed on the coating film. The printing method is not particularly limited, and examples thereof include pad transfer printing. The printing ink used for printing is not particularly limited, and examples thereof include a composition comprising PES, a TFE homopolymer, and titanium oxide.

[0510] <Laminate> The present disclosure also relates to a laminate including the coating film of the present disclosure.

[0511] The laminate of the present disclosure preferably further includes a substrate. The coating film may be provided directly on the substrate, or may be provided on the substrate via another layer. Alternatively, another layer may be provided on the coating film.

[0512] It is also preferable that the laminate has two or more coating layers. For example, the laminate may have a substrate, a primer layer formed on the substrate, and a top coat layer formed on the primer layer. Alternatively, the laminate may have a substrate, a primer layer formed on the substrate, an intermediate layer formed on the primer layer, and a top coat layer formed on the intermediate layer. The intermediate layer may be two or more layers.

[0513] When the laminate has two or more coating films, at least one of the primer layer, intermediate layer, and top coat layer may be the coating film of the present disclosure. When the laminate has two or more coating films of the present disclosure, the two or more coating films may have the same composition or different compositions.

[0514] The laminate preferably further comprises layers other than the substrate and the coating film. These layers are usually provided between the substrate and the coating film.

[0515] The material of the substrate is not particularly limited, and examples thereof include metals such as iron, aluminum, stainless steel, copper, and alloys thereof, and non-metallic inorganic materials such as enamel, glass, ceramic, etc. Examples of alloys include stainless steel.

[0516] The substrate may be subjected to a surface treatment such as degreasing or roughening, as necessary. The roughening method is not particularly limited, and examples thereof include chemical etching with an acid or alkali, anodizing (anodizing), sandblasting, etc. The surface treatment may be appropriately selected depending on the type of substrate and primer coating composition, etc., from the viewpoints of enabling the primer coating composition for forming the primer layer to be uniformly applied without causing cissing and improving adhesion between the substrate and the primer layer, but sandblasting, for example, is preferred.

[0517] The substrate may be one that has been subjected to a degreasing treatment in which oil and other impurities are thermally decomposed and removed by baking at 380° C. In order to improve the adhesion between the substrate and the coating film, it is preferable to use an aluminum substrate that has been subjected to a surface roughening treatment using an alumina abrasive after surface treatment.

[0518] In one embodiment of the laminate of the present disclosure, the primer layer or the intermediate layer is the coating film of the present disclosure. When the primer layer or the intermediate layer is the coating film of the present disclosure, the top coat layer may be the coating film of the present disclosure or a coating film other than the coating film of the present disclosure.

[0519] In another embodiment of the laminate of the present disclosure, the top coat layer is the coating film of the present disclosure. When the top coat layer is the coating film of the present disclosure, the primer layer or the intermediate layer may be the coating film of the present disclosure or a coating film other than the coating film of the present disclosure.

[0520] The primer layer preferably contains a binder resin. Preferred binder resins are the same as the binder resins that can be contained in the coating composition of the present disclosure.

[0521] The content of the binder resin in the primer layer is preferably 10 to 50% by mass, more preferably 15% by mass or more, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0522] The primer layer may contain components other than the binder resin. The components other than the binder resin are not particularly limited, and examples thereof include fluororesins and the various components exemplified as other components. Preferred components other than the binder resin contained in the primer layer include fluororesins (particularly PTFE), pigments, and inorganic fillers.

[0523] The thickness of the primer layer is preferably 1 to 40 μm, and more preferably 5 to 35 μm. If the thickness is too thin, the anchoring effect of the primer surface cannot be expected, pinholes are likely to occur, and the corrosion resistance of the laminate may be reduced. If the thickness is too thick, coating defects such as cracks or blisters are likely to occur, and the abrasion resistance, hardness, and corrosion resistance of the laminate may be reduced. A more preferable upper limit of the thickness of the primer layer is 30 μm, and an especially preferable upper limit is 25 μm.

[0524] The primer layer can be obtained, for example, by applying a primer composition to a substrate, drying it as necessary, and then baking it. The method for applying the primer composition can be the same as the method for applying the coating composition of the present disclosure to a substrate. The drying and baking conditions for the primer composition can be the same as the conditions for drying and baking the coating composition of the present disclosure.

[0525] As the primer composition, a composition containing a binder resin and an aqueous medium is preferred, and a composition containing a binder resin, a fluororesin (particularly PTFE), and an aqueous medium is more preferred.

[0526] The intermediate layer preferably contains a fluororesin, such as PTFE or any of the fluororesins other than PTFE described above, with PTFE being preferred.

[0527] The content of the fluororesin is preferably 60 to 100% by mass, more preferably 65 to 100% by mass, and even more preferably 70 to 100% by mass, relative to the total mass of the intermediate layer. By using the fluororesin in the above range, it is possible to improve the adhesion between the intermediate layer and the coating film adjacent to the intermediate layer.

[0528] The intermediate layer may contain components other than the fluororesin. The components other than the fluororesin are not particularly limited, and for example, the additives exemplified as other components in the coating composition of the present disclosure can be used. The components other than the fluororesin contained in the intermediate layer are preferably a binder resin, a pigment, and an inorganic filler. The content of the inorganic filler is preferably 0.1 to 30% by mass of the intermediate layer, more preferably 20% by mass or less, and more preferably 1% by mass or more.

[0529] The thickness of the intermediate layer is preferably 5 to 30 μm, and more preferably 10 to 25 μm.

[0530] The intermediate layer can be obtained, for example, by applying an intermediate composition onto a primer layer and drying and baking as necessary. When there are two or more intermediate layers, the intermediate compositions for forming each intermediate layer can be applied in order and dried and baked as necessary to form two or more intermediate layers. As a method for applying the intermediate composition, the method described above as a method for applying the coating composition of the present disclosure onto a substrate can be used. As the drying and baking conditions for the intermediate composition, the conditions described above as the drying and baking conditions for the coating composition of the present disclosure can be used.

[0531] The intermediate composition is preferably a composition containing a fluororesin and an aqueous medium, and more preferably a composition containing a binder resin, a fluororesin and an aqueous medium.

[0532] The top coat layer preferably contains a fluororesin, more preferably PTFE. Suitable examples of the fluororesin and PTFE include those described above as the fluororesin and PTFE that can be contained in the coating composition of the present disclosure.

[0533] The content of the fluororesin is preferably 70 to 100% by mass, more preferably 75 to 100% by mass, and even more preferably 80 to 100% by mass, relative to the total mass of the top coat layer. By using the fluororesin in the above range, the non-stickiness of the top coat layer surface can be improved.

[0534] The top coat layer may contain a component other than the fluororesin. The component other than the fluororesin is not particularly limited, and for example, the additives exemplified as other components in the coating composition of the present disclosure can be used. As a component other than the fluororesin contained in the top coat layer, an inorganic filler is preferred.

[0535] The inorganic filler preferably has an average particle size of 14 μm or more. The average particle size of the inorganic filler is more preferably 16 μm or more, and even more preferably 20 μm or more. When the average particle size of the inorganic filler is within the above range, the abrasion resistance of the top coat layer can be improved. In order to further improve the abrasion resistance of the top coat layer, it is preferable that the inorganic filler protrudes from the top coat layer. The average particle size of the inorganic filler is calculated from the particle size distribution obtained by measurement using a laser diffraction / scattering particle size / particle size distribution measuring device (Microtrac MT3300II manufactured by Nikkiso Co., Ltd., medium: pure water, temperature: room temperature).

[0536] The amount of inorganic filler to be added can be adjusted depending on the type, hardness, etc. of the inorganic filler, but the abrasion resistance of the top coat layer can usually be improved by using it in the range of 2 to 10 mass % of the fluororesin.

[0537] The top coat layer preferably has a thickness of 10 to 40 μm. If the thickness is too thin, the non-stickiness, durability, and corrosion resistance of the resulting laminate may be insufficient. If the thickness is too thick, coating defects such as cracks and blisters are likely to occur. The lower limit of the thickness of the top coat layer is more preferably 15 μm or more, and even more preferably 18 μm or more. The upper limit is more preferably 30 μm or less, and even more preferably 25 μm or less.

[0538] The top coat layer can be obtained, for example, by applying a top coat composition to a primer layer or an intermediate layer, drying it as necessary, and then baking it. When the laminate of the present disclosure includes an intermediate layer, it is preferable to apply the intermediate composition to the primer layer, drying it as necessary, and then applying the top coat composition thereon, drying it as necessary, and baking it. This method allows the intermediate layer and the top coat layer to be baked simultaneously, resulting in excellent production efficiency. As a method for applying the top coat composition, the method described above as a method for applying the coating composition of the present disclosure to a substrate can be used. As the drying and baking conditions for the top coat composition, the conditions described above as the drying and baking conditions for the coating composition of the present disclosure can be used.

[0539] When the laminate of the present disclosure includes a top coat layer, letters, drawings, etc. may be printed on the top surface of the top coat layer.

[0540] <Coated Article> The coating film of the present disclosure or the laminate of the present disclosure can also constitute a coated article. The present disclosure also relates to a coated article including the coating film of the present disclosure or the laminate of the present disclosure.

[0541] Examples of coated articles include cooking utensils such as frying pans, grill pans, pressure cookers, other various pots, rice cookers, rice cake makers, ovens, hot plates, bread pans, knives, and gas stoves; food and beverage containers such as electric kettles and ice trays; food industry parts such as kneading rolls, rolling rolls, conveyors, and hoppers; industrial products such as rolls for office automation equipment (OA), OA belts, OA separation claws, papermaking rolls, and calendar rolls for film production; and polystyrene foam molding products. Examples of suitable applications include mold release devices for molds, casting dies, and release plates for manufacturing plywood and decorative panels; kitchen utensils such as range hoods; frozen food manufacturing equipment such as conveyor belts; tools such as saws, files, dies, and drills; household items such as irons, scissors, and knives; metal foils, electric wires; plain bearings for food processing machines, packaging machines, and textile machines; sliding parts for cameras and watches; automotive parts such as pipes, valves, and bearings, snow shovels, plows, chutes, ship bottoms, boilers, and industrial containers (especially for the semiconductor industry).

[0542] Although the 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.

[0543] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0544] The values ​​in the examples were measured by the following methods.

[0545] <Viscosity> Using a Brookfield viscometer (TVB-10 viscometer manufactured by Toki Sangyo Co., Ltd.), the liquid temperature of a coating composition (a top coat coating composition or a primer coating composition; the same applies hereinafter) was brought to 25°C, and then the viscosity was measured at 60 rpm using a No. 2 rotor, and the average value of two measurements was calculated to obtain the measured value.

[0546] <Solids concentration of coating composition> 2 g of the coating composition was dried in a blower dryer at 100°C for 60 minutes and then baked at 380°C for 45 minutes, and the ratio of the mass of the heating residue to the mass (2 g) of the coating composition was expressed as a percentage and used as the solids concentration.

[0547] <Stable Retention Time> 90 g of a sample was placed in a plastic cup having a diameter of 67 mm and an internal volume of 300 ml, and the cup was immersed in a water bath at 60°C. A stirring impeller having a diameter of 50 mm (FIG. 1) was set so that the height from the bottom of the plastic cup to the center of the stirring impeller (a position 6 mm from the bottom end of the stirring impeller in the axial direction of FIG. 1(b)) was 20 mm, and the cup was rotated at 3000 rpm. The time until the sample aggregated or solidified and scattered was measured as the stable retention time.

[0548] <Content of nonionic surfactant in aqueous dispersion> The content (N mass%) of the nonionic surfactant in the aqueous dispersion (either PTFE aqueous dispersions 1 to 3, A, B, FEP aqueous dispersions A, B, or PFA aqueous dispersions A, B; the same applies below) was calculated from the formula: N = [(Y-Z) / Z] x 100 (mass%), by placing about 1 g (X g) of the sample in an aluminum cup with a diameter of 5 cm, heating at 110°C for 30 minutes to obtain a heating residue (Y g), and further heating the obtained heating residue (Y g) at 300°C for 30 minutes to obtain a heating residue (Z g).

[0549] <Solids concentration of aqueous dispersion> The solids concentration (P % by mass) of the aqueous dispersion was calculated from the formula: P = [Z / X] × 100 (% by mass) by placing about 1 g (X g) of the aqueous dispersion in an aluminum cup having a diameter of 5 cm, heating it at 110°C for 30 minutes to obtain a heating residue (Y g), and further heating the obtained heating residue (Y g) at 300°C for 30 minutes to obtain a heating residue (Z g).

[0550] <Content of Polymer A in Aqueous Dispersion> The content of Polymer A in the aqueous dispersion relative to the fluororesin (PTFE, FEP, or PFA) (T Ａ The T mass % was calculated using the following formula from the mass of water added to the reactor in the production example, the mass of polymer A, and the solids concentration of the obtained aqueous dispersion. Ａ =W Ｄ / [(WＷ ×P Ａ / 100) / (1-P Ａ / 100)]×100 (mass%) W Ｗ : mass of water added to the reactor W Ｄ : mass of polymer A added to the reactor P Ａ : solids concentration of aqueous dispersion

[0551] <Content of Polymer A in the Supernatant Phase> A predetermined amount of sodium trifluoroacetate is added to the supernatant phase, １９ F NMR measurement was carried out. From the peak area values ​​of sodium trifluoroacetate and polymer A, the content of polymer A in the upper supernatant phase (T Ｓ The mass % was calculated.

[0552] <Content of Polymer A in Aqueous Dispersion> The content of Polymer A relative to the fluororesin (PTFE, FEP, or PFA) in the aqueous dispersion (T Ｄ The mass % was calculated by the following formula: Ｄ =T Ａ -W Ｓ ×T ２ / W Ａ T Ａ (mass%): content of polymer A in the aqueous dispersion relative to the fluororesin T Ｓ (mass%): content of polymer A in the upper supernatant phase W Ｓ (g): Mass of the upper supernatant phase W Ａ (g): Mass of fluororesin in the aqueous dispersion before concentration (i.e., mass of fluororesin in the concentrated phase)

[0553] <Average primary particle diameter> PTFE aqueous dispersion A was diluted with water to a solid content of 0.15% by mass, and the transmittance of 550 nm projected light per unit length of the diluted latex obtained and the number-based length average primary particle diameter determined by measuring the unidirectional diameter using a transmission electron microscope photograph were measured, and a calibration curve was prepared. Using this calibration curve, the average primary particle diameter was determined from the measured transmittance of 550 nm projected light of each sample.

[0554] <Standard Specific Gravity (SSG)> Using a sample molded in accordance with ASTM D 4895-89, the standard specific gravity was measured by the water displacement method in accordance with ASTM D 792.

[0555] <Fluorine-Containing Surfactant Content> An amount of aqueous dispersion corresponding to 1.5 g of fluororesin solid content in the aqueous dispersion was weighed into a 100 mL screw tube. This was then combined with the water contained in the aqueous dispersion, and water and methanol were added so that the extraction solvent was 37 g of water / methanol = 10 / 90 mass%, followed by thorough shaking until coagulation. The liquid phase was removed and centrifuged at 4000 rpm for 1 hour to extract the supernatant. The fluorine-containing surfactant in the extract was measured using a liquid chromatograph mass spectrometer (Waters, LC-MS ACQUITY UPLC / TQD). The measurement instrument configuration and LC-MS measurement conditions are shown in Table 1.

[0556]

[0557] The calibration curve used to calculate the fluorosurfactant concentration was obtained under the following conditions. Five levels of methanol standard solutions of fluorosurfactants with known concentrations ranging from 1 ng / mL to 100 ng / mL were prepared, and measurements were carried out using a liquid chromatograph mass spectrometer (Waters, LC-MS ACQUITY UPLC / TQD). Using a first-order approximation from the respective sample concentrations and peak integral values, a and b were calculated using the following relational equation (3): A = a × X + b (3) A: peak area of ​​fluorosurfactant X: concentration of fluorosurfactant (ng / mL) The lower limit of quantitation was 100 ppb.

[0558] The surfactants used in the preparation examples are as follows: Surfactant (a): Polyoxyethylene alkyl ether (C １３ H ２７ -(C ２ H ４ O) ｎ -H) (cloud point 60℃)

[0559] <Polymer A> Formula: CH ２ =CF(CF ２ OCFCF ３ COONH ４The number average molecular weight and weight average molecular weight were measured by gel permeation chromatography (GPC) using a GPC HLC-8020 manufactured by Tosoh Corporation and Shodex columns (one GPC KF-801, one GPC KF-802, and two GPC KF-806M columns connected in series) with tetrahydrofuran (THF) as the solvent at a flow rate of 1 ml / min, and the molecular weight was calculated using monodisperse polystyrene as the standard.

[0560] Preparation Example 1 (Preparation of PTFE Aqueous Dispersion A) 3,448 g of deionized water, 180 g of paraffin wax, and 103 g of a 5.0% by mass aqueous solution of Polymer A were placed in a 6 L stainless steel reactor equipped with a stirrer. Ammonia water was added to adjust the pH to 8.7. The contents of the reactor were then heated to 70°C while being aspirated, and simultaneously purged with TFE to remove oxygen from the reactor, and the contents were stirred. 2.4 g of HFP was added to the reactor, and 0.01 g of isopropyl alcohol was added, followed by the addition of TFE until the pressure reached 0.73 MPaG. 25.1 mg of ammonium persulfate (APS) and 537 mg of disuccinic acid peroxide (DSP) dissolved in 20 g of deionized water were added, and the pressure in the reactor was adjusted to 0.83 MPaG. A total of 3,580 g of water was added to the reactor. After the initiator was injected, a decrease in pressure occurred, and the initiation of polymerization was observed. TFE was added to the reactor to maintain a constant pressure of 0.78 MPaG. When the amount of TFE consumed in the reaction reached approximately 180 g, the supply of TFE and stirring were stopped. Next, the gas in the reactor was slowly released until the pressure in the reactor reached 0.02 MPaG. Thereafter, TFE was supplied until the pressure in the reactor reached 0.78 MPaG, and stirring was resumed to continue the reaction. When the amount of TFE consumed in the reaction reached approximately 1,470 g, the supply of TFE was stopped, stirring was stopped, and the reaction was terminated. Thereafter, the pressure in the reactor was vented to atmospheric pressure, and the contents were removed from the reactor and cooled. The supernatant paraffin wax was removed to obtain PTFE aqueous dispersion 1.

[0561] The solid content of the PTFE aqueous dispersion 1 was 29.1% by mass, and the average primary particle size was 250 nm. The concentration of the polymer A relative to the PTFE in the PTFE aqueous dispersion 1 was 0.35% by mass.

[0562] PTFE aqueous dispersion 1 was diluted with deionized water to a solids concentration of approximately 10% by mass, coagulated under high-speed stirring conditions, and the resulting wet powder was dried for 18 hours at 210° C. The resulting PTFE powder had an SSG of 2.201.

[0563] To PTFE aqueous dispersion 1, 15 parts by mass of surfactant (a) was added per 100 parts by mass of PTFE, and then water was added to a solids concentration of 25%, followed by heating in a constant temperature water bath at 62 ° C. After confirming that the contents had reached 62 ° C, the contents were allowed to stand and concentration was initiated, at which point phase separation began (separation into an upper supernatant phase and a concentrated phase). 360 minutes after the start of concentration, heating was terminated, and the upper supernatant phase and the concentrated phase were recovered to obtain upper supernatant phase 1 and PTFE aqueous dispersion 2, respectively. The solids concentration of the resulting PTFE aqueous dispersion 2 was 62%, and the content of surfactant (a) was 3.5% by mass relative to PTFE. The content of polymer A in the resulting upper supernatant phase 1 was 0.10% by mass relative to the upper supernatant phase.

[0564] To the obtained PTFE aqueous dispersion 2, surfactant (a) was added so that the amount was 5.5 mass % relative to PTFE, and ammonium lauryl sulfate was further added in an amount of 2000 ppm relative to PTFE, and deionized water and aqueous ammonia were further added to obtain PTFE aqueous dispersion A.

[0565] The resulting PTFE aqueous dispersion A had a solids concentration of 60.0 mass %, a surfactant (a) content of 5.5 mass % relative to PTFE, and a polymer A content of 0.12 mass % relative to PTFE and 0.072 mass % relative to the PTFE aqueous dispersion.

[0566] Approximately 5 g of a sample of PTFE aqueous dispersion A was weighed out, 10 ml of methanol was added, and the sample was poured into a cylindrical filter paper. Soxhlet extraction was performed so that the total amount of methanol used as the extraction solvent became 100 ml. The obtained extract was concentrated by nitrogen purging as appropriate to obtain an extract. The obtained extract was subjected to LC / MS measurement. The lower detection limit in the measurement was 5 ppb by mass. Fluorine-containing compounds having a hydrophilic group, including all compounds represented by the following formulas, were not detected. F(CF ２ ) ７ COOM, F(CF ２ ) ５ COOM, H(CF ２ ) ６ COOM, H(CF ２ ) ７ COOM, C.F. ３ O (CF ２ ) ３ OCHFCF ２ COOM, C ３ F ７ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ３ CF ２ CF ２ OCF (CF ３ ) COOM, C.F. ３ CF ２ OCF ２ CF ２ OCF ２ COOM, C ２ F ５ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ３ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ２ ClCF ２ CF ２ OCF (CF ３ )CF ２ OCF ２ COOM, C.F. ２ ClCF ２ CF ２ OCF ２CF (CF ３ ) OCF ２ COOM, C.F. ２ ClCF(CF ３ ) OCF (CF ３ )CF ２ OCF ２ COOM, C.F. ２ ClCF(CF ３ ) OCF ２ CF (CF ３ ) OCF ２ COOM, (In each formula, M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0567] Preparation Example 2 (Preparation of FEP aqueous dispersion A) According to Example 24 of WO 2019 / 168183, obtain FEP aqueous dispersion. Phase separation concentration was carried out in the same manner as in Preparation Example 1, obtain FEP aqueous dispersion A. The solid content concentration of the obtained FEP aqueous dispersion A was 54% by mass.

[0568] Preparation Example 3 (Preparation of PFA aqueous dispersion A) A PFA aqueous dispersion was obtained in accordance with Example 22 of WO 2019 / 168183. Phase separation and concentration were carried out in the same manner as in Preparation Example 1 to obtain PFA aqueous dispersion A. The solid content concentration of the obtained PFA aqueous dispersion A was 50% by mass.

[0569] Synthesis Example 1 After replacing the atmosphere in a 1 L autoclave with nitrogen, 16.5 g of dehydrated tetramethylurea and 220 g of diethylene glycol dimethyl ether were charged and cooled. 38.5 g of carbonyl fluoride was charged, followed by the addition of 100 g of hexafluoropropylene oxide and stirring. Subsequently, 38.5 g of carbonyl fluoride and 100 g of hexafluoropropylene oxide were additionally charged. Then, the same amounts of carbonyl fluoride and hexafluoropropylene oxide were further charged. After completion of the reaction, the reaction mixture was removed and separated to obtain the lower layer reaction product.

[0570] A 6-L autoclave was charged with 1,000 ml of tetraglyme and 75 g of CsF, and the atmosphere inside the autoclave was replaced with nitrogen. The autoclave was then cooled, and 2,100 g of the reaction product obtained above was charged. Hexafluoropropylene oxide was then introduced into the autoclave to initiate the reaction. Finally, 1,510 g of hexafluoropropylene oxide was charged. The contents were then removed, and the upper and lower layers were separated using a separatory funnel. The upper layer weighed 1,320 g, and the lower layer weighed 3,290 g. The lower layer was subjected to rectification and isolated.

[0571] Next, 1000 g of purified water was added to 1000 g of the isolated target product to carry out hydrolysis. The liquids were then separated using a separatory funnel, and the organic layer (lower layer) was recovered. The recovered solution was washed with aqueous sulfuric acid. The resulting solution was then purified by simple distillation. After purification, 500 g of the above-obtained simple distillate was added dropwise to an aqueous solution prepared by mixing the obtained compound with 76 g of 28 wt % aqueous ammonia solution and 600 g of pure water. After completion of the dropwise addition, 28 wt % aqueous ammonia solution was added to adjust the pH to 7. This was freeze-dried to obtain an ammonium salt of perfluoroethercarboxylic acid A.

[0572] Preparation Example 4 (Preparation of PTFE Aqueous Dispersion B) Using the ammonium salt of perfluoroethercarboxylic acid A, a PTFE aqueous dispersion B was obtained by a known emulsion polymerization method, a known ion exchange treatment method, and a known phase separation concentration method. The obtained PTFE aqueous dispersion had a solids concentration of 60 mass% and a standard specific gravity of 2.200. The content of the fluorine-containing surfactant (perfluoroethercarboxylic acid A) in the PTFE aqueous dispersion B was 650 ppb.

[0573] Preparation Example 5 (Preparation of FEP aqueous dispersion B) Using the ammonium salt of perfluoroethercarboxylic acid A, a known emulsion polymerization method, a known ion exchange treatment method, and a known phase separation concentration method was used to obtain FEP aqueous dispersion B. The obtained FEP aqueous dispersion had a solid content concentration of 54% by mass and an MFR of 5 g / 10 min.

[0574] Preparation Example 6 (Preparation of PFA aqueous dispersion B) Using an ammonium salt of perfluoroethercarboxylic acid A, a known emulsion polymerization method, a known ion exchange treatment method, and a known phase separation concentration method was used to obtain PFA aqueous dispersion B. The obtained PFA aqueous dispersion had a solids concentration of 50 mass% and an MFR of 29 g / 10 min.

[0575] In addition, the following various materials were used in each example and comparative example. Depolymerizable acrylic resin emulsion: butyl methacrylate-based resin, average particle size 0.3 μm, butyl methacrylate-based resin content 40% by mass; 50% by mass aqueous solution of nonionic surfactant: 50% by mass aqueous solution of polyoxyethylene alkyl ether; Hydrocarbon-based solvent: mixture of C10-12 aliphatic saturated hydrocarbons; Polyimideamide resin aqueous dispersion: aqueous dispersion of polyamideimide resin varnish prepared in accordance with the examples described in JP 2015-127142 A; Carbon black pigment mill base (solid content concentration 20% by mass): aqueous black pigment paste prepared by pulverizing commercially available carbon black pigment (average particle size 100 nm or less) together with a nonionic surfactant and water using a sand mill and glass beads as dispersion media; Thickener: methyl cellulose; Leveling agent: acetylene glycol

[0576] Example 1 A top coat paint composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solid content concentration 60% by mass) 70.0 parts, depolymerizable acrylic resin emulsion 12.6 parts, 50% by mass aqueous solution of nonionic surfactant 7.9 parts, glycerin 3.1 parts, hydrocarbon solvent 1.3 parts, water 5.1 parts. The contents of polymer (I), fluororesin, nonionic surfactant, and ammonium lauryl sulfate in the obtained top coat paint composition were calculated from the blend amounts of each material. The viscosity, solid content, and stability retention time of the obtained top coat paint composition were also measured. The results are shown in Table 2. The content of polymer A was 504 ppm by mass.

[0577] Example 2 A top coat paint composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solid content concentration 60% by mass) 67.0 parts FEP aqueous dispersion A (solid content concentration 54% by mass) 3.0 parts Depolymerizable acrylic resin emulsion 12.6 parts 50% by mass aqueous solution of nonionic surfactant 7.9 parts Glycerin 3.1 parts Hydrocarbon solvent 1.3 parts Water 5.1 parts The obtained top coat paint composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 2.

[0578] Example 3 A top coat paint composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solids concentration 60% by mass) 67.0 parts PFA aqueous dispersion A (solids concentration 50% by mass) 3.0 parts Depolymerizable acrylic resin emulsion 12.6 parts 50% by mass aqueous solution of nonionic surfactant 7.9 parts Glycerin 3.1 parts Hydrocarbon solvent 1.3 parts Water 5.1 parts The obtained top coat paint composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 2.

[0579] Example 4 A top coat paint composition was obtained by stirring and mixing the following components: FEP aqueous dispersion A (solid content concentration 54% by mass) 78.0 parts, 50% by mass aqueous solution of nonionic surfactant 7.9 parts, glycerin 3.1 parts, hydrocarbon solvent 1.3 parts, water 9.7 parts. Calculations and measurements were performed on the obtained top coat paint composition in the same manner as in Example 1. The results are shown in Table 2.

[0580] Example 5 A top coat paint composition was obtained by stirring and mixing the following components: PFA aqueous dispersion A (solid content concentration 50% by mass) 84.0 parts 50% by mass aqueous solution of nonionic surfactant 7.9 parts Glycerin 3.1 parts Hydrocarbon solvent 1.3 parts Water 3.7 parts The obtained top coat paint composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 2.

[0581] Comparative Example 1 A top coat paint composition was obtained in the same manner as in Example 1, except that 70.0 parts of PTFE aqueous dispersion B was used instead of 70.0 parts of PTFE aqueous dispersion A. For the obtained top coat paint composition, calculations and measurements were carried out in the same manner as in Example 1. The results are shown in Table 2. The content of perfluoroethercarboxylic acid A in the obtained top coat paint composition was 455 ppb.

[0582] Comparative Example 2 A top coat paint composition was obtained in the same manner as in Comparative Example 1, except that the amount of PTFE aqueous dispersion B added was changed from 70.0 parts to 67.0 parts, and 3.0 parts of FEP aqueous dispersion B was further added. The obtained top coat paint composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 2.

[0583] Comparative Example 3 A top coat paint composition was obtained in the same manner as in Comparative Example 1, except that the amount of PTFE aqueous dispersion B added was changed from 70.0 parts to 67.0 parts, and 3.0 parts of PFA aqueous dispersion B was further added. The obtained top coat paint composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 2.

[0584]

[0585] Example 6 A primer coating composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solid content concentration 60% by mass) 40.0 parts Polyamideimide resin aqueous dispersion 39.0 parts 50% by mass aqueous solution of nonionic surfactant 8.0 parts Carbon black pigment mill base (solid content concentration 20% by mass) 3.6 parts Thickener 7.0 parts Leveling agent 1.0 part Water 1.4 parts The resulting primer coating composition was calculated and measured in the same manner as in Example 1. The results are shown in Table 3. The content of polymer A was 288 ppm by mass.

[0586] Example 7 A primer coating composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solid content concentration 60% by mass) 36.0 parts FEP aqueous dispersion A (solid content concentration 54% by mass) 4.0 parts Polyamideimide resin aqueous dispersion 39.0 parts 50% by mass aqueous solution of nonionic surfactant 8.0 parts Carbon black pigment mill base (solid content concentration 20% by mass) 3.6 parts Thickener 7.0 parts Leveling agent 1.0 part Water 1.4 parts The resulting primer coating composition was calculated and measured in the same manner as in Example 1. The results are shown in Table 3.

[0587] Example 8 A primer coating composition was obtained by stirring and mixing the following components: PTFE aqueous dispersion A (solid content concentration 60% by mass) 27.0 parts FEP aqueous dispersion A (solid content concentration 54% by mass) 13.0 parts Polyamideimide resin aqueous dispersion 39.0 parts 50% by mass aqueous solution of nonionic surfactant 8.0 parts Carbon black pigment mill base (solid content concentration 20% by mass) 3.6 parts Thickener 7.0 parts Leveling agent 1.0 part Water 1.4 parts The resulting primer coating composition was calculated and measured in the same manner as in Example 1. The results are shown in Table 3.

[0588] Comparative Example 4 A primer coating composition was obtained in the same manner as in Example 6, except that 40.0 parts of PTFE aqueous dispersion B was used instead of 40.0 parts of PTFE aqueous dispersion A. For the obtained primer coating composition, calculations and measurements were carried out in the same manner as in Example 1. The results are shown in Table 3. The content of perfluoroether carboxylic acid A in the obtained primer coating composition was 260 ppb.

[0589] Comparative Example 5 A primer coating composition was obtained in the same manner as in Comparative Example 4, except that the amount of PTFE aqueous dispersion B added was changed from 40.0 parts to 36.0 parts, and 4.0 parts of FEP aqueous dispersion B was added. The obtained primer coating composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 3.

[0590] Comparative Example 6 A primer coating composition was obtained in the same manner as in Comparative Example 4, except that the amount of PTFE aqueous dispersion B added was changed from 40.0 parts to 27.0 parts, and 13.0 parts of FEP aqueous dispersion B was added. The obtained primer coating composition was subjected to calculations and measurements in the same manner as in Example 1. The results are shown in Table 3.

[0591]

Claims

1. A paint composition containing a fluororesin, a polymer (I) containing a polymerizable unit (I) based on a monomer represented by the general formula (I), and an aqueous medium, wherein the content of the polymer (I) is 2000 ppm by mass or less with respect to the paint composition. CX １ X ３ =CX ２ R(−CZ １ Z ２ −A ０ ) ｍ (I) (In the formula, X １ and X ３ are each independently F, Cl, H or CF ３ ; X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; m is an integer of 1 or more.) 2. The paint composition according to claim 1, wherein the viscosity is 100 mPa·s or more and 1000 mPa·s or less.

3. The paint composition according to claim 1 or 2, wherein the content of the fluororesin is 15.0% by mass or more and 52.0% by mass or less based on the paint composition.

4. The paint composition according to any one of claims 1 to 3, wherein the fluororesin is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, ethylene / tetrafluoroethylene copolymer, and ethylene / chlorotrifluoroethylene copolymer.

5. The paint composition according to any one of claims 1 to 4, wherein the stability retention time measured by a stirring test is 10 minutes or more.

6. The paint composition according to any one of claims 1 to 5, wherein the content of the polymer (I) is 0.1 mass ppm or more based on the paint composition.

7. The paint composition according to any one of claims 1 to 6, further containing a nonionic surfactant.

8. A paint composition containing a fluororesin and an aqueous medium, wherein the stability retention time measured by a stirring test is 10 minutes or more, and the viscosity is 50 mPa·s or more and 1000 mPa·s or less.

9. The paint composition according to claim 8, wherein the content of the fluororesin is 15.0% by mass or more and 52.0% by mass or less based on the paint composition.

10. The paint composition according to claim 8 or 9, containing at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer as the fluororesin.

11. The paint composition according to claim 8 or 9, containing at least polytetrafluoroethylene as the fluororesin.

12. The paint composition according to claim 11, wherein the content of polytetrafluoroethylene in the paint composition is 60% by mass or more based on the fluororesin.

13. The paint composition according to claim 8 or 9, containing only tetrafluoroethylene / hexafluoropropylene copolymer as the fluororesin, and the content of the fluororesin is 30.0% by mass or more and 50.0% by mass or less based on the paint composition.

14. The coating composition according to claim 8 or 9, wherein the fluororesin contains only a tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, and the content of the fluororesin is 30.0% by mass or more and 50.0% by mass or less based on the coating composition.

15. A coating composition containing a fluororesin, a nonionic surfactant, an anionic hydrocarbon surfactant, and an aqueous medium, and substantially free of a fluorine-containing compound containing a hydrophilic group.

16. The coating composition according to claim 15, wherein the fluorine-containing compound containing a hydrophilic group is an anionic fluorine-containing surfactant containing fluorine and having a molecular weight of 800 or less in the anionic moiety.

17. The coating composition according to claim 15 or 16, wherein the content of the fluorine-containing compound containing a hydrophilic group is 100 mass ppb or less.

18. The fluorine-containing compound containing the hydrophilic group is H(CF ２ ), ７ COOM F(CF ２ ), ７ COOM, F(CF ２ ), ５ COOM, H(CF ２ ), ６ COOM, CF ３ O(CF ２ ), ３ OCHFCF ２ COOM, C ３ F ７ OCF(CF ３ ), ２ OCF(CF ３ ), ３ COOM, CF ２ CF ２ OCF(CF ３ ), ３ CF ２ OCF ２ CF ２ OCF ２ COOM, C ２ F ５ OCF(CF ３ ), ２ OCF(CF ３ ), ３ COOM, CF ３ OCF(CF ２ ), ３ OCF(CF ２ ), ２ COOM, CF ２ ClCF ３ CF ２ OCF(CF ２ ), ２ ClCF ２ CF ２ OCF ２ CF(CF ３ ), ２ OCF ２ COOM, CF ３ ClCF(CF ３ ), ２ OCF ２ COOM, CF ２ ClCF(CF ３ ), OCF ２ CF (CF ３ ) OCF ２ COOM, and (wherein M is H, a metal atom, NR ７ ４ , imidazolium which may have a substituent, pyridinium which may have a substituent or phosphonium which may have a substituent). The coating composition according to any one of claims 15 to 17, which is a compound represented by 19. The coating composition according to any one of claims 15 to 18, wherein the content of the fluororesin is 15.0% by mass or more and 52.0% by mass or less based on the coating composition.

20. The coating composition according to any one of claims 15 to 19, wherein the fluororesin contains at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer.

21. The coating composition according to any one of claims 15 to 19, wherein the fluororesin contains at least polytetrafluoroethylene.

22. The coating composition according to claim 21, wherein the content of polytetrafluoroethylene in the coating composition is 60% by mass or more based on the fluororesin.

23. The coating composition according to any one of claims 1 to 22, further containing a film-forming agent.

24. The coating composition according to any one of claims 1 to 23, further containing a binder resin, and the binder resin is at least one selected from the group consisting of polyamideimide, polyimide, polyethersulfone, and polyphenylene sulfide.

25. A coating film obtained by applying the coating composition according to any one of claims 1 to 24.

26. A laminate comprising the coating film according to claim 25.

27. A coated article comprising the coating film according to claim 25 or the laminate according to claim 26.