Fluorine-based graft copolymer or its salt, and coating agent

Abstract

To provide a fluorine-based graft copolymer or a salt thereof that can be dissolved in water and can form a coating layer to exhibit fluorine properties such as water- and oil-repellence and stain resistance, antistatic properties, and durability in a balanced manner.SOLUTION: The present invention discloses a fluorine-based graft copolymer or a salt thereof, prepared by polymerizing a monomer component containing the following (A), (B) and (C): (A) a polymerizable unsaturated monomer having an amino group; (B) a polymerizable unsaturated monomer having a carboxyl group; and (C) a fluorine-based macro monomer having a polymerizable unsaturated functional group at an end.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a fluorine-based graft copolymer or a salt thereof, and a coating agent.

Background Art

[0002] In a coating agent for imparting water and oil repellency and stain resistance to the surface of a substrate, it has been proposed to use a graft copolymer obtained by copolymerizing a fluorine-based macromonomer and another monomer (see, for example, Patent Document 1). Patent Document 1 discloses a fluorine-based graft copolymer composed of a fluorine-based polymer having a crosslinkable functional group in the main chain and a crosslinkable functional group introduced into the side chain, and a coating liquid containing the fluorine-based graft copolymer. In Patent Document 1, by arranging a fluorine segment in the graft chain portion of the copolymer, while reducing the fluorine content of the fluorine-based graft copolymer to reduce the cost, a coating film that sufficiently exhibits properties due to fluorine such as water and oil repellency and stain resistance is obtained. Further, in Patent Document 1, a coating liquid is prepared using methyl ethyl ketone as a solvent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] From the viewpoint of environmental protection, the water-based conversion of paints is being studied. However, generally, when a polymer is converted to an aqueous solution, the water repellency and toughness of the coating film tend to decrease. In addition, a coating film formed by a coating agent is required to exhibit not only water and oil repellency and toughness, but also stain resistance and a property of being less likely to generate static electricity.

[0005] The fluorine-based graft copolymer described in Citation Document 1 can exhibit high levels of water and oil repellency even when the fluorine content is reduced, shows good fluorine characteristics, and can form a tough coating film due to the crosslinkable functional groups introduced into the main chain and side chains. However, the fluorine-based graft copolymer described in Citation Document 1 is insoluble in water and difficult to use as an aqueous coating agent.

[0006] The present invention has been made in view of the above circumstances, and its main object is to provide a fluorine-based graft copolymer or a salt thereof that can be dissolved in water and can form a coating film that exhibits good balance of fluorine characteristics such as water and oil repellency and stain resistance, antistatic property, and durability.

Means for Solving the Problems

[0007] The inventors of the present invention have intensively studied to solve the above problems and completed the present invention by using a graft copolymer having a specific functional group in the main chain and a fluorine segment in the side chain. According to the present invention, the following means are provided.

[0008] 〔1〕 A fluorine-based graft copolymer or a salt thereof obtained by polymerizing a monomer component containing the following (A), (B), and (C). (A) A polymerizable unsaturated monomer having an amino group. (B) A polymerizable unsaturated monomer having a carboxyl group. (C) A fluorine-based macromonomer having a polymerizable unsaturated functional group at the terminal. 〔2〕 The monomer component contains 10 to 60% by mass of the (C) fluorine-based macromonomer, and the fluorine-based graft copolymer or a salt thereof according to the above 〔1〕. 〔3〕 The monomer component contains 5 to 50% by mass of the (A) monomer and 5 to 40% by mass of the (B) monomer, and the fluorine-based graft copolymer or a salt thereof according to the above 〔1〕 or 〔2〕. [4] The (C) fluoromacromonomer contains a structural unit derived from a crosslinkable functional group-containing monomer, and the crosslinkable functional group-containing monomer contains a monomer having 10 or more carbon atoms having a structure derived from a cyclic ester or a polyether structure. The fluorine-based graft copolymer according to any one of [1] to [3] above or a salt thereof. [5] The fluorine-based graft copolymer according to [4] above or a salt thereof, wherein the average number of moles of addition of the cyclic ester in the monomer having a structure derived from the cyclic ester is 2 moles or more. [6] The fluorine-based graft copolymer according to [4] or [5] above or a salt thereof, wherein the content of the crosslinkable functional group in the (C) fluoromacromonomer is 0.2 to 2.0 meq / g. [7] The fluorine-based graft copolymer according to any one of [1] to [6] above or a salt thereof, wherein the (C) fluoromacromonomer contains 20 to 95% by mass of a structural unit derived from a monomer having a fluorine atom with respect to all the structural units of the (C) fluoromacromonomer. [8] The fluorine-based graft copolymer according to any one of [1] to [7] above or a salt thereof, wherein the weight average molecular weight of the (C) fluoromacromonomer is 4000 to 23000. [9] A method for producing a fluorine-based graft copolymer or a salt thereof, comprising a step of polymerizing a monomer component containing the above (A), (B) and (C).

[10] A coating agent containing the fluorine-based graft copolymer according to any one of [1] to [8] above or a salt thereof.

[11] The coating agent according to

[10] above, further containing a crosslinking agent. [Advantages of the Invention]

[0009] According to the present invention, it is possible to form a coating film that exhibits fluorine characteristics such as water and oil repellency and stain resistance, antistatic properties, and durability in a well-balanced manner. In addition, since the fluorine-based graft copolymer of the present invention is soluble in water, it is not necessary to use an organic solvent when preparing a coating agent containing a polymer component in a medium. Therefore, according to the present invention, an environmentally friendly coating agent can be obtained. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, the present invention will be described in detail. In this specification, "(meth)acryl" means acrylic and / or methacrylic, and "(meth)acrylate" means acrylate and / or methacrylate. The "(meth)acryloyl group" means an acryloyl group and / or a methacryloyl group.

[0011] 《Fluorine-based graft copolymer or its salt》 The fluorine-based graft copolymer or its salt of the present invention (hereinafter, also referred to as "the present graft copolymer") can be obtained by polymerizing monomer components including the following (A), (B), and (C). (A) A polymerizable unsaturated monomer having an amino group. (B) A polymerizable unsaturated monomer having a carboxyl group. (C) A fluorine-based macromonomer having a polymerizable unsaturated functional group at its terminal. Hereinafter, each monomer will be described.

[0012] <(A) monomer> Examples of the polymerizable unsaturated monomer having an amino group (hereinafter, also referred to as "(A) monomer") include primary amino group-containing vinyl monomers, secondary amino group-containing vinyl monomers, tertiary amino group-containing vinyl monomers or their salts, and quaternary ammonium salts of vinyl monomers obtained by reacting tertiary amino group-containing vinyl monomers with quaternizing agents. As the (A) monomer, one kind may be used alone, or two or more kinds may be used in combination. Preferred examples of the (A) monomer include compounds represented by the following formula (1) or their salts. CH 2 =C(R 1 )-CO-X 1 -(CH 2 ) a -X 2 …(1) (In formula (1), R 1 is a hydrogen atom or a methyl group. X 1 is -O- or -NH-. X2 is a group containing a primary amino group, a secondary amino group, a tertiary amino group or a quaternary ammonium salt structure. a is an integer from 1 to 5.)

[0013] (A) Specific examples of the monomer include, as a primary amino group-containing vinyl monomer, 2-aminoethyl (meth)acrylate, 3-aminopropyl (meth)acrylate, 2-aminoethyl (meth)acrylamide, 3-aminopropyl (meth)acrylamide and the like. Examples of the secondary amino group-containing vinyl monomer include 2-(N-methylamino)ethyl (meth)acrylate, 2-(N-ethylamino)ethyl (meth)acrylate, 2-(N-methylamino)ethyl (meth)acrylamide, 2-(N-ethylamino)ethyl (meth)acrylamide and the like. Examples of the tertiary amino group-containing vinyl monomer include 2-(dimethylamino)methyl (meth)acrylate, 2-(diethylamino)methyl (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, 2-(diethylamino)ethyl (meth)acrylate, 3-(dimethylamino)propyl (meth)acrylate, 3-(dimethylamino)propyl (meth)acrylamide and the like. The quaternary ammonium salt of the vinyl monomer obtained by reacting the tertiary amino group-containing vinyl monomer with a quaternizing agent may be an inorganic acid salt such as a hydrochloride or a sulfate, or an organic acid salt such as an acetate. Examples of the quaternizing agent to be reacted include methyl chloride, benzyl chloride, dimethyl sulfate, epichlorohydrin and the like. Among these, the tertiary amino group-containing vinyl monomer or its salt can be preferably used.)

[0014] In the production of this graft copolymer, the amount of monomer (A) used is preferably 1 to 60% by mass based on the total amount of monomer components used in the production of this graft copolymer. When the amount of monomer (A) used is 1% by mass or more, the solubility of this graft copolymer in water can be sufficiently increased, and a tougher and more excellent antistatic coating layer can be formed. On the other hand, when the amount of monomer (A) used is 60% by mass or less, a structural unit derived from the (C) fluorine-based macromonomer can be sufficiently introduced into this graft copolymer, and in the resulting coating film, fluorine characteristics such as water / oil repellency and stain resistance can be sufficiently increased. From these viewpoints, the lower limit of the amount of monomer (A) used is more preferably 5% by mass or more, and even more preferably 10% by mass or more. The upper limit of the amount of monomer (A) used is more preferably 50% by mass or less, and even more preferably 40% by mass or less. The range of the amount of monomer (A) used is more preferably 5 to 50% by mass, and even more preferably 10 to 40% by mass based on the total amount of monomer components.

[0015] <(B) monomer> As the polymerizable unsaturated monomer having a carboxyl group (hereinafter also referred to as “(B) monomer”), a vinyl-based monomer containing a carboxyl group can be used. Specific examples thereof include, for example, (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, caffeic acid, maleic anhydride, monobutyl itaconate, monobutyl maleate, cyclohexanedicarboxylic acid and the like. The carbon number of the (B) monomer is not particularly limited, but is preferably 20 or less, more preferably 10 or less, and even more preferably 6 or less. As the (B) monomer, one kind may be used alone, or two or more kinds may be used in combination.

[0016] When polymerizing the graft copolymer, the amount of the monomer (B) used is preferably 1 to 50% by mass based on the total amount of the monomer components used in the production of the graft copolymer. When the amount of the monomer (B) used is 1% by mass or more, the solubility of the graft copolymer in water can be sufficiently increased, and a tougher coating layer can be formed. On the other hand, when the amount of the monomer (B) used is 50% by mass or less, a structural unit derived from the (C) fluorine-based macromonomer can be sufficiently introduced into the graft copolymer, and the fluorine characteristics of the coating film can be sufficiently increased. From these viewpoints, the lower limit of the amount of the monomer (B) used is more preferably 5% by mass or more, and even more preferably 10% by mass or more. The upper limit of the amount of the monomer (B) used is more preferably 40% by mass or less, and even more preferably 30% by mass or less. The range of the amount of the monomer (B) used is more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass based on the total amount of the monomer components.

[0017] The ratio of the monomer (A) to the monomer (B) used in the production of the graft copolymer is preferably (A) monomer / (B) monomer = 10 / 90 to 90 / 10 in terms of mass ratio. When the ratio of the monomer (A) to the monomer (B) is within the above range, it is preferable in that the solubility of the graft copolymer in water and the effect of improving the durability of the coating film can be sufficiently obtained. (A) monomer / (B) monomer is more preferably 15 / 85 to 85 / 15, and even more preferably 20 / 80 to 80 / 20.

[0018] <(C) fluorine-based macromonomer> (C) The fluorine-based macromonomer is a high-molecular-weight monomer containing fluorine atoms and having a polymerizable unsaturated functional group at its terminal. By copolymerizing the (C) fluorine-based macromonomer with the (A) monomer and the (B) monomer, a graft copolymer having fluorine atoms in its side chains can be obtained. Further, by adopting a structure having a fluorine segment in the side chain, the copolymer can effectively exhibit fluorine characteristics. Thereby, even if the fluorine content is relatively small, excellent performance as a fluorine-based coating agent can be exhibited. That is, according to this graft copolymer, a coating agent that provides a coating layer excellent in water and oil repellency and stain resistance can be obtained while achieving cost reduction.

[0019] From the viewpoint of copolymerizability, the polymerizable unsaturated functional group possessed by the (C) fluorine-based macromonomer is preferably a functional group containing a vinyl group, more preferably a (meth)acryloyl group or a vinylphenyl group, and even more preferably a (meth)acryloyl group. The (C) fluorine-based macromonomer can be obtained by polymerizing a monomer component containing a monomer having fluorine atoms (hereinafter also referred to as "fluorine-containing monomer").

[0020] (Fluorine-containing monomer) The fluorine-containing monomer is preferably a vinyl-based monomer. Specific examples of the fluorine-containing monomer include (meth)acrylic monomers such as trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, heptafluoropropyl (meth)acrylate, nonafluorobutyl (meth)acrylate, undecafluoropentyl (meth)acrylate, tridecafluorohexyl (meth)acrylate, pentadecafluoroheptyl (meth)acrylate, and the compound represented by the following formula (2); fluoroethylenes such as monofluoroethylene, difluoroethylene, trifluoroethylene, chlorotrifluoroethylene, and tetrafluoroethylene; vinylidene fluoride, vinyl fluoride, hexafluoropropylene, and the like. CH 2 =C(R 2 )-COO-(CH 2 ) m -(CF2 ) n -Z 1 …(2) (In formula (2), R 2 is a hydrogen atom or a methyl group. Z 1 is a hydrogen atom or a fluorine atom. m is an integer from 1 to 4. n is an integer from 1 to 20.)

[0021] In the above formula (2), Z 1 is preferably a fluorine atom. From the viewpoint of availability, m is preferably 1 or 2. From the viewpoint of obtaining a coating layer that sufficiently exhibits fluorine characteristics, n is preferably 2 or more, and more preferably 4 or more. Regarding the upper limit of n, from the viewpoints of ensuring the safety of the compound, solubility in water, and compatibility with other components, it is preferably 12 or less, more preferably 10 or less, and still more preferably 8 or less.

[0022] Specific examples of the compound represented by the above formula (2) include, by trade name, CHEMINOX FAAC-4, FAAC-6, FAMAC-4, FAMAC-6 (above, manufactured by Unimatec); R-1420, R-1620, R-5410, R-5610, M-1420, M-1620, M-5410, M-5610 (above, manufactured by Daikin); Light Acrylate FA-108 (manufactured by Kyoeisha Chemical Co., Ltd.); Biscoat-3FM, -8F, -8FM (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), etc.

[0023] Among these, from the viewpoints of copolymerizability and handleability, (meth)acrylic monomers are preferred as the fluorine-containing monomer, and from the viewpoints of availability and cost, the compound represented by the above formula (2) is more preferred. Also, since the characteristics of fluorine are likely to appear and the durability tends to increase, acrylate compounds can be more preferably used as the fluorine-containing monomer.

[0024] (Monomer containing a crosslinkable functional group) (C) The fluorine-based macromonomer preferably contains a structural unit derived from a crosslinkable functional group-containing monomer (hereinafter also referred to as "crosslinkable functional group-containing monomer") together with a structural unit derived from a fluorine-containing monomer. By introducing a crosslinkable functional group into the (C) fluorine-based macromonomer, a tough coating layer with excellent durability can be obtained. From the viewpoint of ease of controlling the crosslinking reaction and the physical properties of the coating layer after crosslinking, a hydroxyl group, a carboxyl group, or a (meth)acryloyl group is preferable as the crosslinkable functional group. Among these, a hydroxyl group or a carboxyl group is more preferable, and a hydroxyl group is particularly preferable.

[0025] From the viewpoint of allowing the crosslinking reaction to proceed sufficiently, the crosslinkable functional group-containing monomer preferably has a crosslinkable functional group at the terminal position on the side opposite to the polymerizable unsaturated functional group (i.e., the ω-position). More specifically, the crosslinkable functional group-containing monomer more preferably contains a monomer having 5 or more carbon atoms with a crosslinkable functional group at the ω-position, and particularly preferably contains a monomer having 10 or more carbon atoms with a crosslinkable functional group at the ω-position (hereinafter also referred to as "monomer M1"). When a crosslinkable functional group is introduced into the side chain (branched polymer) by monomer M1, the presence of crosslinking points at a position sufficiently distant from the branched polymer makes it difficult to hinder the surface orientation of the fluorine segment, which is preferable in terms of ensuring excellent water and oil repellency.

[0026] Monomer M1 preferably has a structure derived from a cyclic ester or a polyether structure in terms of obtaining a coating layer with high durability. Examples of such monomer M1 include compounds in which a cyclic ester is added to hydroxyalkyl (meth)acrylate (hereinafter also referred to as "cyclic ester adduct"), polyalkylene glycol mono(meth)acrylates, ω-carboxy-polycaprolactone mono(meth)acrylate, and the like. The carbon number of monomer M1 is more preferably 12 or more and 40 or less, and even more preferably 12 or more and 30 or less.

[0027] Specific examples of the cyclic ester adducts include compounds obtained by adding cyclic esters such as ε-caprolactone and δ-valerolactone to 2-hydroxyethyl (meth)acrylate. Commercially available products of such compounds include Placcel FA1DDM, FA2D, FA3D, FA10L, FM2D, FM3, and FM5 (manufactured by Daicel Corporation) under their trade names. Specific examples of polyalkylene glycol mono(meth)acrylates include polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and (meth)acrylate compounds of polyethylene / polypropylene block bodies. A specific example of ω-carboxy-polycaprolactone mono(meth)acrylate is Aronix M-5300 (manufactured by Toagosei Co., Ltd.) under its trade name.

[0028] In addition, when producing the (C) fluorine-based macromonomer, a monomer having less than 10 carbon atoms may be used as the crosslinkable functional group-containing monomer. Examples of the monomer having less than 10 carbon atoms include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate.

[0029] Among the above, in terms of being able to obtain a coating layer with high durability, the crosslinkable functional group-containing monomer preferably includes a monomer having 10 or more carbon atoms having a structure derived from a cyclic ester or a polyether structure, and more preferably includes a monomer having 10 or more carbon atoms having a structure derived from a cyclic ester. In the monomer having 10 or more carbon atoms having a structure derived from a cyclic ester, the average number of added moles of the cyclic ester is preferably 2 moles or more, and more preferably 2 to 4 moles. Note that the crosslinkable functional group-containing monomer can be used alone or in combination of two or more.

[0030] (Other monomers) In the production of the fluorine-based macromonomer, a monomer different from the fluorine-containing monomer and the crosslinkable functional group-containing monomer (hereinafter also referred to as "other monomer") may be used in combination within a range that does not impair the fluorine properties. The other monomer is not particularly limited as long as it is a monomer copolymerizable with the fluorine-containing monomer and the crosslinkable functional group-containing monomer.

[0031] Specific examples of the other monomer include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, amyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and octadecyl (meth)acrylate; aliphatic cyclic esters of (meth)acrylic acid such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; aromatic esters of (meth)acrylic acid such as phenyl methacrylate, benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and 3-phenoxypropyl (meth)acrylate; styrenes such as styrene, α-methylstyrene, and p-methylstyrene. As the other monomer, one of these may be used alone, or two or more thereof may be used in combination. It is preferable that the other monomer does not contain a monomer having an amino group.

[0032] (Production of Fluorine-based Macromonomer) (C) The method for producing the fluorine-based macromonomer is not particularly limited, but from the viewpoint of copolymerizability, it is preferably by a radical polymerization method. The (C) fluorine-based macromonomer can be obtained, for example, by polymerizing the above monomer by adopting a known radical polymerization method such as a solution polymerization method in the presence of a chain transfer agent having a plurality of active hydrogen groups, thereby obtaining a polymer having an active hydrogen group at the polymerization terminal. Then, it can be produced by reacting the obtained polymer with a compound having a polymerizable unsaturated functional group and capable of reacting with the active hydrogen group (hereinafter, also referred to as "polymerizable terminal-imparting compound").

[0033] In the case of the solution polymerization method, an organic solvent and a monomer are charged into a reactor, and a polymerization initiator is added and copolymerized to obtain the target polymer. The charging method of each raw material containing the monomer may be a batch-type initial one-shot charging in which all raw materials are charged at once, a semi-continuous charging in which at least one kind of raw material is continuously supplied into the reactor, or a continuous polymerization method in which all raw materials are continuously supplied and the produced resin is continuously withdrawn from the reactor at the same time.

[0034] The organic solvent used in the solution polymerization method is preferably an organic hydrocarbon-based compound. Specific examples of the organic solvent include aromatic compounds such as benzene, toluene, xylene, and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; 、 ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; cyclic ethers such as tetrahydrofuran and dioxane; dimethylformamide, acetonitrile, dimethyl sulfoxide, alcohol, etc. As the organic solvent, one of these may be used alone, or two or more thereof may be used in combination.

[0035] As the polymerization initiator, known radical polymerization initiators such as azo compounds, organic peroxides, and persulfates can be used. Among these, azo compounds are preferred in terms of being easy to handle safely and having few side reactions during radical polymerization. Specific examples of azo compounds include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and the like. As the polymerization initiator, only one kind may be used, or two or more kinds may be used in combination.

[0036] The amount of the polymerization initiator used is not particularly limited, but from the viewpoint of stably performing the polymerization reaction, it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. Regarding the upper limit of the amount of the polymerization initiator used, it is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer.

[0037] As the chain transfer agent, known compounds can be used. For example, hydroxyl group-containing thiol compounds such as 2-mercaptoethanol, 3-mercaptopropanol, and thioglycerol; carboxyl group-containing thiol compounds such as thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, α-mercaptoisobutyric acid, methyl mercaptopropionate, ethyl mercaptopropionate, thioacetic acid, thiomalic acid, and thiosalicylic acid; and the like. (C) When producing a fluorine-based macromonomer, by using a hydroxyl group-containing thiol compound as the chain transfer agent, a hydroxyl group can be introduced to the polymerization terminal. Further, by using a carboxyl group-containing thiol compound as the chain transfer agent, a carboxyl group can be introduced to the polymerization terminal. Furthermore, by carrying out the polymerization reaction in the presence of a chain transfer agent, the molecular weight of the macromonomer can be adjusted. The amount of the chain transfer agent used is not particularly limited, but is, for example, 0.01 to 5% by mass based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. As the chain transfer agent, one kind may be used alone, or two or more kinds may be used in combination.

[0038] In the above polymerization reaction, the usage amount of the fluorine-containing monomer is preferably 20% by mass or more based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. When the usage amount of the fluorine-containing monomer is 20% by mass or more, a coating film that sufficiently exhibits fluorine characteristics such as water repellency, oil repellency, and stain resistance can be obtained. The usage amount of the fluorine-containing monomer is more preferably 30% by mass or more and even more preferably 40% by mass or more based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. Regarding the upper limit of the usage amount of the fluorine-containing monomer, from the viewpoint of obtaining a highly durable coating layer, it is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 85% by mass or less based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. The range of the usage amount of the fluorine-containing monomer is preferably 20 to 99% by mass, more preferably 20 to 95% by mass, and even more preferably 40 to 85% by mass based on the total monomers used for the polymerization of the (C) fluorine-based macromonomer.

[0039] The usage amount of the crosslinkable functional group-containing monomer is preferably 1% by mass or more based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. When the usage amount of the crosslinkable functional group-containing monomer is 1% by mass or more, the durability of the coating film formed using this graft copolymer can be sufficiently increased. The usage amount of the crosslinkable functional group-containing monomer is more preferably 2% by mass or more, even more preferably 5% by mass or more, and even more preferably 10% by mass or more based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer. Regarding the upper limit of the usage amount of the crosslinkable functional group-containing monomer, from the viewpoint of sufficiently ensuring fluorine characteristics, it is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less based on the total monomers used for the polymerization of the (C) fluorine-based macromonomer. The range of the usage amount of the crosslinkable functional group-containing monomer is preferably 1 to 80% by mass, more preferably 5 to 80% by mass, and even more preferably 15 to 60% by mass based on the total amount of the monomers used for the polymerization of the (C) fluorine-based macromonomer.

[0040] Among the crosslinkable functional group-containing monomers, the amount of monomer M1 (more preferably, a monomer having a structure derived from a cyclic ester or a polyether structure) used is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more based on the total amount of the crosslinkable functional group-containing monomers.

[0041] From the viewpoint of enhancing the durability of the coating film obtained using this graft copolymer, the amount of monomers having less than 10 carbon atoms used is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and even more preferably 1% by mass or less based on the total amount of the crosslinkable functional group-containing monomers.

[0042] From the viewpoint of sufficiently obtaining the effects of the present invention, the amount of other monomers used is preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 20% by mass or less, and even more preferably 10% by mass or less based on the total monomers used for the polymerization of the (C) fluorine-based macromonomer.

[0043] The reaction temperature in the polymerization reaction is preferably 40 to 150°C, more preferably 45 to 110°C. When the reaction temperature is 40°C or higher, the polymerization reaction can proceed smoothly. When it is 150°C or lower, side reactions can be suppressed, and the restrictions on the polymerization initiators and organic solvents that can be used are relaxed, which is preferable. The reaction time can be appropriately set according to the monomers used, etc., but is preferably 1 to 48 hours, more preferably 3 to 24 hours.

[0044] (C) To obtain a fluorine-based macromonomer, subsequently, a polymer having an active hydrogen group at the polymerization terminal obtained by the above polymerization reaction is reacted with a polymerizable terminal-introducing compound. The polymerizable terminal-introducing compound is not particularly limited as long as it is a compound having a functional group capable of reacting with an active hydrogen group and a polymerizable unsaturated functional group. Examples thereof include epoxy compounds having a (meth)acryloyl group, epoxy compounds having a vinylphenyl group, carboxylic acids having a (meth)acryloyl group, carboxylic acids having a vinylphenyl group, isocyanate compounds having a (meth)acryloyl group, and the like. As the polymerizable terminal-introducing compound, one kind may be used alone, or two or more kinds may be used.

[0045] The reaction between the polymer having an active hydrogen group at the polymerization terminal and the polymerizable terminal-introducing compound is preferably carried out in an organic solvent in the presence of an appropriate catalyst as necessary. Examples of the organic solvent used in the reaction include the solvents exemplified as the organic solvents used as the polymerization solvent. The reaction temperature and reaction time can be appropriately set according to the compounds used in the reaction and the like. For example, the reaction can be carried out under the conditions of 40 to 170 °C and 1 to 24 hours. In the following polymerization reaction for obtaining this graft copolymer, the (C) fluorine-based macromonomer obtained by the above reaction may be used as a solution dissolved in an organic solvent, or may be used after distilling off the organic solvent by heat treatment under reduced pressure or the like.

[0046] (C) The weight average molecular weight (Mw) of the fluorine-based macromonomer is preferably 4000 or more. When Mw is 4000 or more, the fluorine characteristics can be sufficiently enhanced. The Mw of the (C) fluorine-based macromonomer is more preferably 4500 or more, and still more preferably 5000 or more. Regarding the upper limit of Mw of the (C) fluorine-based macromonomer, it is preferably 23000 or less. When Mw exceeds 23000, the polymerizability of this graft copolymer may decrease. Further, due to an increase in the proportion of the linear polymer without side chains being introduced, the fluorine characteristics may not be effectively exhibited. Regarding the upper limit of Mw, 15000 or less is more preferable, and 10000 or less is still more preferable. The range of Mw of the (C) fluorine-based macromonomer is preferably from 4000 to 23000, more preferably from 4500 to 20000, still more preferably from 5000 to 15000, and even more preferably from 5000 to 10000. In the present specification, the weight average molecular weight (Mw) of the (C) fluorine-based macromonomer is a value in terms of polystyrene measured by gel permeation chromatography (GPC).

[0047] (C) In the fluorine-based macromonomer, the content of the crosslinkable functional group is preferably in the range of 0.1 to 4.0 meq / g. When the content of the crosslinkable functional group is 0.1 meq / g or more, the durability of the coating film formed using this graft copolymer can be sufficiently increased. Also, when the content of the crosslinkable functional group is 4.0 meq / g or less, the stain resistance of the coating film surface can be sufficiently ensured. From these viewpoints, the content of the crosslinkable functional group is more preferably 0.2 meq / g or more, still more preferably 0.3 meq / g or more, even more preferably 0.4 meq / g or more, and particularly preferably 0.5 meq / g or more. Regarding the upper limit of the content of the crosslinkable functional group, it is more preferably 3.0 meq / g or less, still more preferably 2.0 meq / g or less, even more preferably 1.0 meq / g or less, and particularly preferably 0.8 meq / g or less. The range of the content of the crosslinkable functional group is more preferably 0.1 to 3.0 meq / g, still more preferably 0.2 to 2.0 meq / g, and even more preferably 0.2 to 1.0 meq / g. Note that the content of the crosslinkable functional group can be calculated from the charging ratio of the monomers.

[0048] In the production of this graft copolymer, the amount of the (C) fluorine-based macromonomer used is preferably 5 to 75% by mass based on the total amount of the monomer components of this graft copolymer. When the amount of the (C) fluorine-based macromonomer used is 5% by mass or more, the fluorine characteristics such as water and oil repellency and stain resistance in this graft copolymer can be sufficiently increased, and when it is 75% by mass or less, the solubility in water can be increased. From these viewpoints, regarding the lower limit of the amount of the (C) fluorine-based macromonomer used, it is more preferably 10% by mass or more, still more preferably 15% by mass or more, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more. Regarding the upper limit of the amount of the (C) fluorine-based macromonomer used, it is more preferably 70% by mass or less, still more preferably 65% by mass or less, and particularly preferably 60% by mass or less. Also, the range of the amount of the (C) fluorine-based macromonomer used is more preferably 10 to 70% by mass, still more preferably 10 to 60% by mass based on the total amount of the monomer components.

[0049] <(D) monomer> The monomer components used in the production of this graft copolymer may further contain a monomer (A), a monomer (B), and a monomer different from the fluorine-based macromonomer (C) (hereinafter also referred to as “monomer (D)”). The monomer (D) is not particularly limited as long as it is copolymerizable with the monomer (A), the monomer (B), and the fluorine-based macromonomer (C). Examples of the monomer (D) include the compounds exemplified as other monomers that may be used in the production of the fluorine-based macromonomer (C). In terms of being able to increase the glass transition temperature of this graft copolymer and obtain a coating film with high strength, the monomer (D) is preferably at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, isobornyl (meth)acrylate, and styrenes, and particularly preferably at least one selected from the group consisting of methyl (meth)acrylate and isobornyl (meth)acrylate. Note that this graft copolymer substantially does not have fluorine atoms in the main chain. Specifically, it is preferable that the monomer (D) does not contain a monomer having a fluorine atom.

[0050] When polymerizing this graft copolymer, the amount of the monomer (D) used is preferably 80% by mass or less, more preferably 70% by mass or less, and still more preferably 50% by mass or less, based on the total amount of the monomer components used in the production of this graft copolymer. Regarding the lower limit of the amount of the monomer (D) used, it is preferably 1% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more, based on the total amount of the monomer components used in the production of this graft copolymer. As the monomer (D), one kind may be used alone, or two or more kinds may be used in combination.

[0051] <Production of Fluorine-based Graft Copolymer> The method for producing the present graft copolymer is not particularly limited, but from the viewpoint of copolymerizability, it is preferably by a radical polymerization method. The present graft copolymer can be obtained by polymerizing a monomer component containing the above-mentioned (A) monomer, (B) monomer, and (C) fluorine-based macromonomer by adopting a known radical polymerization method such as a solution polymerization method. Regarding the details of the solvent, polymerization initiator, etc. used in the polymerization reaction, the above description regarding the production method of the (C) fluorine-based macromonomer can be applied. The present graft copolymer obtained by the polymerization reaction may be directly used as a solution dissolved in an organic solvent for the preparation of a coating agent, or may be used after the organic solvent is distilled off by heating under reduced pressure or the like.

[0052] When the present graft copolymer is in the form of a salt, the types of counterions of the cationic functional group and anionic functional group possessed by the present graft copolymer are not particularly limited. Specific examples of counterions include, as anionic counterions, for example, chloride ion, bromide ion, iodide ion, etc.; as cationic counterions, for example, sodium ion, magnesium ion, calcium ion, etc. can be respectively mentioned.

[0053] The weight average molecular weight (Mw) of the present graft copolymer is preferably 10,000 or more. When Mw is 10,000 or more, the strength of the coating film obtained using the present graft copolymer can be sufficiently high and the durability can be enhanced. The Mw of the present graft copolymer is more preferably 12,000 or more, and still more preferably 15,000 or more. Regarding the upper limit of Mw of the present graft copolymer, it is preferably 100,000 or less. When Mw is 100,000 or less, the viscosity of the solution for forming the coating film does not become too high, and the coatability can be improved. From such a viewpoint, the upper limit of Mw is more preferably 80,000 or less, and still more preferably 50,000 or less. The range of Mw of the present graft copolymer is preferably 10,000 to 100,000, and more preferably 15,000 to 50,000. In the present specification, the Mw of the present graft copolymer is a value in terms of polystyrene measured by GPC.

[0054] "Coating Agent" The coating agent of the present invention (hereinafter, also referred to as "this coating agent") contains the present graft copolymer obtained above. Note that the present graft copolymer contained in this coating agent may be only one kind, or two or more kinds. Further, this coating agent may consist only of the present graft copolymer obtained above, but may further contain components different from the present graft copolymer as necessary.

[0055] (Crosslinking Agent) This coating agent can, as necessary, further contain a crosslinking agent in addition to the fluorine-based graft copolymer. The crosslinking agent to be used is not particularly limited as long as it can undergo a crosslinking reaction with the crosslinkable functional group introduced into the present graft copolymer. As the crosslinking agent, a water-soluble compound can preferably be used. For example, epoxy-based crosslinking agents, isocyanate-based crosslinking agents, amino resin-based crosslinking agents, carbodiimide-based crosslinking agents, hydrazide-based crosslinking agents, and oxazoline-based crosslinking agents can be mentioned. Among these, at least one selected from the group consisting of epoxy-based crosslinking agents, carbodiimide-based crosslinking agents, and isocyanate-based crosslinking agents is preferable in terms of reactivity and ease of control.

[0056] Specific examples of the crosslinking agent include, as epoxy-based crosslinking agents, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol Z-type epoxy resins, and bisphenol-type epoxy resins such as hydrogenated bisphenol-type epoxy resins; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diglycidylamine, N,N,N',N'-tetraglycidyl-m-xylenediamine, and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, etc.

[0057] Specific examples of the isocyanate-based crosslinking agent include p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, 4,4'-diphenylene diisocyanate, 1,5-octylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, diphenylmethane diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, and carbodiimide-modified 4,4'-diphenylmethane diisocyanate, etc.

[0058] Examples of the amino resin-based crosslinking agent include alkyl etherified melamine, alkyl etherified urea resin, and alkyl etherified benzoguanamine, etc. Among these, examples of the alkyl etherified melamine include fully alkyl etherified melamine such as hexamethoxymethylol melamine and hexabutoxymethylol melamine, and partially alkyl etherified melamine with an alkyl etherification degree of 5 or less, etc. Also, multimers such as dimers and trimers of alkyl etherified melamine can be used.

[0059] Examples of the carbodiimide-based crosslinking agent include 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, polycarbodiimide resin, etc. Examples of the polycarbodiimide resin include commercially available products such as Carbodilite V-02, V-02-L2, SV-02, V-04, V-10, SW-12G (all manufactured by Nisshinbo Chemical Inc.).

[0060] The compounding amount of the crosslinking agent is preferably in the range of 0.1 to 10 equivalents, more preferably 0.2 to 5 equivalents, and even more preferably 0.5 to 2 equivalents, relative to the amount of crosslinkable functional groups possessed by the graft copolymer. The crosslinking reaction of the graft copolymer can be appropriately set according to the types of crosslinkable functional groups and crosslinking agents used, etc., and can be carried out, for example, under heating conditions of about 80 to 200°C. Further, for the purpose of accelerating the crosslinking reaction, a known curing catalyst (such as an organic base, etc.) may be compounded together with the crosslinking agent.

[0061] When the crosslinkable functional group is a polymerizable vinyl group, a photoinitiator can be added as necessary to obtain an active energy ray-curable coating agent. When a photoinitiator is compounded, examples of the photoinitiator include benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, acylphosphine oxides, and α-diketones, etc. Among these, benzophenones and thioxanthones are preferable in terms of fast polymerization rate. The compounding amount of the photoinitiator is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the graft copolymer.

[0062] Also, for the purpose of improving the sensitivity to active energy rays, a photosensitizer can be used together with the photoinitiator. Examples of the photosensitizer include benzoic acid-based and amine-based photosensitizers, etc. Here, examples of the active energy rays include visible light, ultraviolet rays, X-rays, and electron beams, etc. Among these, ultraviolet rays are preferably used as the active energy rays because an inexpensive device can be used. Examples of the light source when using ultraviolet rays include ultra-high pressure, high pressure, medium pressure, or low pressure mercury lamps, metal halide lamps, xenon lamps, electrodeless discharge lamps, and carbon arc lamps, etc. The ultraviolet irradiation can be, for example, several seconds to several minutes.

[0063] The coating agent may further contain a fluorine-free binder component capable of forming a coating layer alone. As the fluorine-free binder, various known general-purpose polymers and oligomers can be used. Among these, an acrylic polymer having a crosslinkable functional group of the same type as the fluorine-based graft copolymer of the present invention can be preferably used. The blending amount of the fluorine-free binder is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, based on 1 part by mass of the graft copolymer in terms of solid content.

[0064] The coating agent can also be blended with silica, titanium oxide, etc. for the purpose of improving the coating film strength and adjusting the volume resistivity, etc., as long as the fluorine characteristics and durability of the coating film formed using the coating agent are not impaired. The blending ratios thereof can be appropriately set as long as the effects of the present invention are not impaired.

[0065] The coating agent may be a composition in which the graft copolymer and, if necessary, additives are dispersed or dissolved in a solvent. Examples of the solvent include water, organic solvents, and mixed solvents of water and organic solvents. Among these, a solvent capable of dissolving the graft copolymer is preferred, a mixed solvent of water or an organic solvent soluble in water and water is more preferred, and water is particularly preferred.

[0066] Examples of organic solvents used together with water include alcohols such as methanol, ethanol, propanol, and butanol; ketones such as acetone and methyl ethyl ketone; alkylene glycols such as ethylene glycol and propylene glycol; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, and tetrahydrofuran; esters such as ethylene glycol monomethyl ether acetate and ethyl acetate; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; etc. As the organic solvent, one kind can be used alone or two or more kinds can be used in combination. The amount of the organic solvent used is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total amount of the solvent.

[0067] When an aqueous solvent is used as the solvent component of this coating agent, a neutralizing agent may be used to dissolve this graft copolymer in the aqueous solvent. The neutralizing agent is not particularly limited, and known acids or bases can be used. Specific examples of the neutralizing agent include, as acids, for example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, lactic acid, citric acid, etc.; as bases, for example, ammonia, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, tributylamine, triethanolamine, sodium hydroxide, potassium hydroxide, etc. The amount of the neutralizing agent used can be appropriately set according to the type of the neutralizing agent, etc. For example, it is 0.2 to 1.5 molar equivalents with respect to the ionic functional groups possessed by this graft copolymer.

[0068] When the coating agent is in a liquid state, the solid content concentration of the coating agent (that is, the ratio of the mass of components other than the solvent in the coating agent to the total mass of the coating agent) is preferably 1 to 60% by mass. When the solid content concentration is 1% by mass or more, a coating layer having sufficient thickness and strength can be formed. Further, when the solid content concentration is 60% by mass or less, good coatability can be ensured, and a coating layer with a uniform thickness is easily formed. The solid content concentration of the coating agent is more preferably 3 to 50% by mass, and still more preferably 5 to 30% by mass.

[0069] This coating agent is useful for applications to impart water and oil repellency and stain resistance to the surface of a substrate made of various materials such as resin, rubber, metal, glass, ceramic, wood, fiber, and leather. Specifically, it can be used as a paint, a surface modifier, a water and oil repellent, and an antistatic agent for construction, automobiles, electronic components, etc. Further, it can be used as a coating agent for peripheral members of a copying machine such as an ink ejection part of an inkjet printer, a photoreceptor, a rubber roll, a carrier, and other internal parts.

Examples

[0070] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In the following, unless otherwise specified, "part" means "part by mass" and "%" means "% by mass". The macromonomer, graft copolymer, and coating agent obtained in each example were evaluated by measuring the following physical properties and characteristics.

[0071] (1) Characteristics of macromonomer and graft copolymer a) Solid content Approximately 1 g of the measurement sample was weighed (a), and then the residue after drying in a ventilating dryer at 155°C for 30 minutes was measured (b), and calculated from the following formula. A weighing bottle was used for the measurement. For other operations, JIS K 0067-1992 (Test method for loss in mass and residue of chemical products) was followed. [Solid content (%)] = (b / a) × 100 b) Molecular weight The molecular weight was measured by gel permeation chromatography (GPC method). First, the sample was dissolved in tetrahydrofuran (hereinafter referred to as "THF") to prepare a 0.2% solution, and then 100 μL of this solution was injected into a column (manufactured by Tosoh Corporation, "TSK-GEL MULTIPORE HXL-M" (4 columns)). The component adsorbed on the column was eluted by passing THF through the column at a flow rate of 1.0 mL / min at a column temperature of 40 °C. The number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated from a calibration curve prepared in advance using polystyrene with a known molecular weight as a standard substance. c) Solubility of the graft copolymer in water The graft copolymer and water were mixed, and a neutralizing agent was added thereto to prepare a 1% solid content mixture. This mixture was heated at 40 °C for 10 minutes, and after cooling to 25 °C, the appearance was visually confirmed and evaluated according to the following criteria. As the neutralizing agent, ammonia equivalent to the amount of carboxyl groups of each graft copolymer A1 to A33, B1 and copolymer B3 was used. For graft copolymer B2, hydrochloric acid equivalent to the amount of amino groups of graft copolymer B2 was used. ○: Completely dissolved △: Partially dissolved ×: Insoluble

[0072] (2) Characteristics of the coating agent a) Contact angle, contact angle after wear test, and friction durability Using an automatic contact angle measuring device "OCA-20" (manufactured by Dataphysics), the contact angles of pure water and n-hexadecane (HD) with respect to each test coating film sample were measured. It can be said that the larger the contact angle of pure water, the better the water repellency, and the larger the contact angle of n-hexadecane, the better the oil repellency. Thereafter, a nylon scrubbing brush was placed on the coating film sample, and a friction test of 10 reciprocations was performed with a load of 1 kg using a rubbing tester (manufactured by Dai-Ei Kagaku Seisakusho, Gakushin type dyed fabric rubbing fastness tester). Similar to the above, the contact angles of pure water and n-hexadecane (contact angles after the friction test) were measured respectively. Also, as an index of friction durability, the ratio Rt of the contact angle after the test to the contact angle before the test [Rt = (contact angle after the test / contact angle before the test) × 100, unit: %] was calculated for each of pure water and n-hexadecane. It can be said that the larger the value of the ratio Rt, the better the friction durability. b) Antistatic property Under the environment of temperature 25°C × humidity 40%RH, the test coating film sample was rubbed 30 times with a 100% nylon cloth and left standing for 1 minute. Then, using an electrostatic measuring instrument "Statiron DZ4" (manufactured by Shishido Electrostatic Co., Ltd.), the amount of static electricity on the surface of the coating film was measured. The amount of static electricity is represented by a negative value, and it can be said that the larger the numerical value (that is, the smaller the absolute value), the better the antistatic property. c) Magic ink stain resistance A line was drawn on the surface of each test coating film sample with black magic ink, and after 1 hour, the ink was wiped off with a paper towel. The ease of wiping off the ink at that time was evaluated according to the following criteria. ◎: Can be wiped off with a light force and no trace remains. ○: Can be wiped off by applying a slightly stronger force, but a slight trace remains. △: Can be wiped off by applying a strong force, but an obvious trace remains. ×: Almost cannot be wiped off.

[0073] <Manufacture of macromonomer> 〔Synthesis Example 1: Manufacture of macromonomer A〕 Into a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube, and a thermometer, 80 parts of 2-(perfluorohexyl)ethyl methacrylate (manufactured by Unimatec Co., Ltd., trade name "CHEMINOX FAMAC-6") as a monomer, 20 parts of a caprolactone 2 mol adduct of 2-hydroxyethyl methacrylate (manufactured by Daicel Corporation, trade name "Placcel FM2D"), 100 parts of butyl acetate as a polymerization solvent, and 2.5 parts of 3-mercaptopropionic acid (hereinafter referred to as "MPA") as a chain transfer agent were charged, and the mixture was heated and stirred at 90 °C under a nitrogen stream. In a separate container, 0.5 part of 2,2'-azobis(2-methylbutyronitrile) (manufactured by Nippon Fine Chemical Co., Ltd., trade name "ABN-E") was added to 20 parts of butyl acetate and dissolved to prepare a polymerization initiator solution. While maintaining the solution in the flask at 90 °C, this polymerization initiator solution was dropped into the flask over 3 hours. Polymerization was completed by continuing heating and stirring for another 3 hours to obtain a polymer having a carboxyl group at one end. The nitrogen stream was switched to air bubbling, and subsequently, 0.01 part of methoxyphenol, 0.6 part of tetrabutylammonium bromide, and 3.5 parts of glycidyl methacrylate (hereinafter referred to as "GMA") as a polymerizable terminal group-introducing compound were added to the same flask and heated at 110 °C for 7 hours, then cooled to room temperature. Butyl acetate was added to adjust the solid content to 50% to obtain a butyl acetate solution of macromonomer A having a methacryloyl group at one end. When the molecular weight of the obtained macromonomer A was measured, the number average molecular weight (Mn) = 5,900 and the weight average molecular weight (Mw) = 8,500. This macromonomer A has a hydroxyl group equivalent to 0.54 meq / g as a crosslinkable functional group.

[0074] 〔Synthesis Examples 2 to 15, 17, 18: Production of Macromonomers B to O, Q, R〕 The same operations as in Synthesis Example 1 were carried out except that the monomers, chain transfer agents, and polymerizable terminal group-introducing compounds were used as shown in Table 1 to obtain butyl acetate solutions of macromonomers B to O, Q, R. The physical property values of the obtained macromonomers are shown in Table 1.

[0075] 〔Synthesis Example 16: Production of Macromonomer P〕 Into a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube, and a thermometer, 80 parts of 2-(perfluorohexyl)ethyl acrylate (manufactured by Unimatec Co., Ltd., trade name "CHEMINOX FAAC-6") as a monomer, 20 parts of ω-carboxy-polycaprolactone (n≈2) monoacrylate (manufactured by Toagosei Co., Ltd., trade name "ARONIX M-5300"), 100 parts of butyl acetate as a polymerization solvent, and 1.1 parts of 2-mercaptoethanol (hereinafter referred to as "MTG") as a chain transfer agent were charged, and the mixture was heated and stirred at 90 °C under a nitrogen stream. In a separate container, 1.0 part of ABN-E was added to 20 parts of butyl acetate and dissolved to prepare a polymerization initiator solution. While maintaining the solution in the flask at 90 °C, this polymerization initiator solution was dropped into the flask over 3 hours. Polymerization was completed by continuing heating and stirring for another 3 hours to obtain a polymer having a hydroxyl group at one end. The nitrogen stream was switched to air bubbling, and subsequently, 0.02 part of methoxyphenol, 0.01 part of dioctyltin dilaurate (manufactured by Nitto Kasei Co., Ltd., trade name "Neostan U-810"), and 2.2 parts of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko K.K., trade name "Karenz MOI") as a polymerizable end-capping compound were added to the same flask and heated at 110 °C for 3 hours, then cooled to room temperature, and butyl acetate was added to adjust the solid content to 50%, thereby obtaining a butyl acetate solution of macromonomer P having a methacryloyl group at one end and a carboxyl group as a crosslinkable functional group. The physical property values of the obtained macromonomer P are shown in Table 1.

[0076]

Table 1

[0077] The details of the compounds shown in Table 1 are as follows. · 3FM: 2,2,2-Trifluoroethyl methacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Biscoat-3FM") · FAAC-4: 2-(Perfluorobutyl)ethyl acrylate (manufactured by Unimatec Co., Ltd., trade name "CHEMINOX FAAC-4") · FAAC-6: 2-(Perfluorohexyl)ethyl acrylate (manufactured by Unimatec, trade name "CHEMINOX FAAC-6") · FAMAC-6: 2-(Perfluorohexyl)ethyl methacrylate (manufactured by Unimatec, trade name "CHEMINOX FAMAC-6") · FA-108: 2-(Perfluorooctyl)ethyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Light Acrylate FA-108") · HEA: 2-Hydroxyethyl acrylate · FA1DDM: Caprolactone 1 mol adduct of HEA (manufactured by Daicel Corporation, trade name "Placcel FA1DDM") · FA2D: Caprolactone 2 mol adduct of HEA (manufactured by Daicel Corporation, trade name "Placcel FA2D") · FM2D: Caprolactone 2 mol adduct of 2-Hydroxyethyl methacrylate (HEMA) (manufactured by Daicel Corporation, trade name "Placcel FM2D") · FA3D: Caprolactone 3 mol adduct of HEA (manufactured by Daicel Corporation, trade name "Placcel FA3D") · AE-200: Polyethylene glycol monoacrylate (manufactured by NOF Corporation, trade name "Blemmer AE-200") · M-5300: ω-Carboxy-polycaprolactone (n≈2) monoacrylate (manufactured by Toagosei Co., Ltd., trade name "Aronix M-5300") · MMA: Methyl methacrylate · MPA: 3-Mercaptopropionic acid · MTG: 2-Mercaptoethanol · GMA: Glycidyl methacrylate · MOI: 2-Isocyanatoethyl methacrylate (manufactured by Showa Denko K.K., trade name "Karex MOI")

[0078] <Production of copolymer> 〔Production Example 1: Production of Graft Copolymer A1〕 Into a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube, and a thermometer, 20 parts (10 parts as solid content) of a butyl acetate solution of the macromonomer A obtained above, 18 parts of 2-(dimethylamino)ethyl methacrylate (manufactured by Mitsubishi Gas Chemical Company, hereinafter referred to as "DAM"), 10 parts of methacrylic acid (hereinafter referred to as "MAA"), 62 parts of methyl methacrylate (hereinafter referred to as "MMA"), 50 parts of methyl ethyl ketone (hereinafter referred to as "MEK"), and 150 parts of isopropyl alcohol (hereinafter referred to as "IPA") were charged, and the mixture was heated and stirred at 80 °C under a nitrogen stream. In a separate container, 1.0 part of ABN-E was added to 10 parts of MEK and 10 parts of IPA and dissolved to prepare a polymerization initiator solution. While maintaining the solution in the flask at 80 °C, this polymerization initiator solution was dropped into the flask over 2 hours. Further, polymerization was completed by continuing heating and stirring for 3 hours to obtain a MEK / IPA solution of graft copolymer A1. The obtained graft copolymer solution was vacuum dried at 60 °C for 12 hours and pulverized to obtain powdery graft copolymer A1. When the solubility of graft copolymer A1 in water was confirmed, it was completely dissolved in water.

[0079] 〔Production Examples 2 to 33: Production of Graft Copolymers A2 to A33〕 The same operations as in Production Example 1 were carried out except that the monomers constituting the main chain and the macromonomer serving as the side chain were used as shown in Tables 2 and 3 to obtain graft copolymers A2 to A33. The evaluation results of the solubility in water of each of the obtained graft copolymers are shown in Tables 2 and 3.

[0080]

Table 2

[0081]

Table 3

[0082] 〔Comparative Production Examples 1 to 3: Production of Graft Copolymers B1, B2 and Copolymer B3〕 The monomers and macromonomers were changed as shown in Table 4, and the same operations as in Production Example 1 were carried out to obtain each of copolymers B1 to B3. In Comparative Production Example 3, no macromonomer was used. Table 4 shows the evaluation results of the solubility in water of each of the obtained copolymers B1 to B3.

[0083]

Table 4

[0084] The details of the compounds shown in Tables 2 to 4 are as follows. ·DAM: 2-(dimethylamino)ethyl methacrylate (manufactured by Mitsubishi Gas Chemical Company) ·DMAPAA: 3-(dimethylamino)propyl acrylamide (manufactured by KJ Chemicals) ·MAA: Methacrylic acid ·MMA: Methyl methacrylate ·IBXMA: Isobornyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Light Ester IB-X")

[0085] Among the copolymers produced in each of the above examples, the copolymers of Production Examples A1 to A7, A9 to A33 and Comparative Production Examples B1, B3 were completely dissolved in water. Also, the copolymer of Production Example A8 was partially dissolved in water. This is presumably because the content of the fluorine-based macromonomer unit in the copolymer of Production Example A8 is larger than that in other examples. On the other hand, the copolymer of Comparative Production Example B2 having no unsaturated carboxylic acid monomer unit was insoluble in water.

[0086] <Production and Evaluation of Coating Agent> 〔Example 1〕 100 parts by solid content of the graft copolymer A1 obtained in Production Example 1, 4.0 parts of 25% aqueous ammonia (half equivalent of the amount of carboxyl groups of the graft copolymer) as a neutralizing agent, 10.1 parts of Denacol EX-810 (manufactured by Nagase ChemteX Corporation, epoxy-based crosslinking agent) (equivalent to the amount of carboxyl groups of the graft copolymer) as a crosslinking agent, and 0.5 parts of DBU (1,8-diazabicyclo[5.4.0]undecene) (0.5% based on the graft copolymer) as a curing catalyst were mixed, and diluted with water to a solid content of 10% to prepare a coating solution. This coating solution was applied onto a PET film (manufactured by Toyobo Co., Ltd., trade name "A4300", 188 μm) using a bar coater No. 24, and then dried and crosslinked at 100 °C for 30 minutes in a ventilation dryer to obtain a test coating film sample A1. Table 6 shows the results of evaluating various properties of the coating solution for the coating film sample A1.

[0087] [Examples 2 to 34 and Comparative Examples 1 to 3] The types and amounts of the copolymer, crosslinking agent, and curing accelerator were changed as shown in Table 5. Regarding the neutralizing agent, ammonia equivalent to half the amount of carboxyl groups of each copolymer was used for each of the copolymers A1 to A33, B1, and B3, and hydrochloric acid equivalent to half the amount of amino groups of the graft copolymer B2 was used for the graft copolymer B2. Coating film samples were obtained by the same operations as in Example 1. Table 6 shows the evaluation results of each coating film sample. In Table 5, the numerical values of the crosslinking agent and curing catalyst indicate the blending amounts [parts] of each component per 100 parts of the copolymer. In Table 6, "HD" represents n-hexadecane.

[0088]

Table 5

[0089] Details of the compounds used in Table 5 are shown below. (Crosslinking agent) EX-810: Denacol EX810 (manufactured by Nagase ChemteX Corporation, epoxy-based crosslinking agent) V-02: Carbodiite V-02 (manufactured by Nisshinbo Chemical Inc., polycarbodiimide resin) (Curing catalyst) DBU: 1,8-Diazabicyclo[5.4.0]undec-7-ene

[0090] [Table 6]

[0091] In Examples 1 to 34 using the graft copolymer of the present invention, a coating film showing good water and oil repellency could be obtained. Further, the coating films obtained in Examples 1 to 34 could wipe off the magic ink adhering to their surfaces and had good stain resistance. In particular, in Examples 5 to 7 where the content of the (C) fluorine-based macromonomer unit was 50 to 60% by mass, the magic ink on the surface could be wiped off with a light force, showing excellent stain resistance.

[0092] In addition, the coating films obtained in Examples 1 to 34 also had good friction durability and antistatic properties. Looking in detail at the friction durability, Examples 1 to 32 and 34 using a fluorine-based graft copolymer having a crosslinkable functional group had a larger value of contact angle after the test / contact angle before the test (ratio Rt) compared to Example 33 using a fluorine-based graft copolymer having no crosslinkable functional group, and were excellent in durability. However, when the content of the crosslinkable functional group in the (C) fluorine-based macromonomer was relatively low at 0.14 meq / g (Example 21), the value of the ratio Rt was smaller compared to when the crosslinkable functional group was sufficiently large (for example, Example 18). Also, in Examples using a monomer having 10 or more carbon atoms as the crosslinkable functional group-containing monomer (for example, Examples 1 to 20, 22 to 31), the contact angle after the friction test was higher than that of Example 32 using 2-hydroxyethyl acrylate, showing better durability.

[0093] On the other hand, in Comparative Example 1 using a graft copolymer having (B) monomer units and not having (A) monomer units, and Comparative Example 2 using a graft copolymer having (A) monomer units and not having (B) monomer units, the contact angles after the friction test were small for both water and n-hexadecane, and the friction durability was inferior to that of Examples 1 to 34. Further, the coating film obtained in Comparative Example 1 showed a large negative value of -4.5 kV for the amount of static electricity and was also inferior in antistatic properties. In Comparative Example 3 using a copolymer not having (C) fluorine-based macromonomer units, both the fluorine characteristics and the durability were inferior.

[0094] From the above results, it became clear that by using the fluorine-based graft copolymer or a salt thereof of the present invention, a coating film can be formed that exhibits water and oil repellency, stain resistance, antistatic properties, and durability in a well-balanced manner.

Claims

1. A fluorine-based graft copolymer or a salt thereof, obtained by polymerizing a monomer component containing the following (A), (B), and (C), wherein the monomer component contains 5 to 50% by mass of the (A) monomer, 5 to 40% by mass of the (B) monomer, and 10 to 75% by mass of the (C) fluorine-based macromonomer. (A) A compound represented by the following formula (1) or a salt thereof. CH₂=C(R₁)-CO-X₁-(CH₂)ₐ-X₂ …(1) (In formula (1), R₁ is a hydrogen atom or a methyl group. X₁ is -O- or -NH-. X₂ is a group containing a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium salt structure. a is an integer of 1 to 5.) (B) At least one selected from the group consisting of (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, cinnamic acid, maleic anhydride, itaconic acid monobutyl, maleic acid monobutyl, and cyclohexanedicarboxylic acid. (C) A fluorine-based macromonomer having a polymerizable unsaturated functional group at the terminal.

2. The fluorine-based graft copolymer or a salt thereof according to claim 1, wherein the monomer component contains 10 to 60% by mass of the (C) fluorine-based macromonomer.

3. The (C) fluorine-based macromonomer contains a structural unit derived from a crosslinkable functional group-containing monomer, The fluorine-based graft copolymer or a salt thereof according to claim 1 or 2, wherein the crosslinkable functional group-containing monomer contains a monomer having 10 or more carbon atoms having a structure derived from a cyclic ester or a polyether structure.

4. The fluorine-based graft copolymer or a salt thereof according to claim 3, wherein the average number of moles of addition of the cyclic ester in the monomer having a structure derived from the cyclic ester is 2 moles or more.

5. The fluorine-based graft copolymer or a salt thereof according to claim 3 or 4, wherein the content of the crosslinkable functional group in the (C) fluorine-based macromonomer is 0.2 to 2.0 meq / g.

6. The fluorine-based graft copolymer or a salt thereof according to any one of claims 1 to 5, wherein the (C) fluorine-based macromonomer contains 20 to 95% by mass of a structural unit derived from a monomer having a fluorine atom with respect to all the structural units of the (C) fluorine-based macromonomer.

7. The weight average molecular weight of the (C) fluorine-based macromonomer is from 4,000 to 23,000, the fluorine-based graft copolymer or a salt thereof according to any one of claims 1 to 6.

8. including a step of polymerizing a monomer component containing the following (A), (B), and (C), a method for producing a fluorine-based graft copolymer or a salt thereof, wherein the monomer component contains 5 to 50% by mass of the (A) monomer, 5 to 40% by mass of the (B) monomer, and 10 to 75% by mass of the (C) fluorine-based macromonomer. (A) A compound represented by the following formula (1) or a salt thereof. CH2 = C(R1) - CO - X1 - (CH2)a - X2 …(1) (In formula (1), R1 is a hydrogen atom or a methyl group. X1 is -O- or -NH-. X2 is a primary amino group, secondary amino group, tertiary amino group, or a group containing a quaternary ammonium salt structure. a is an integer of 1 to 5.) (B) At least one selected from the group consisting of (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, cinnamic acid, maleic anhydride, itaconic acid monobutyl, maleic acid monobutyl, and cyclohexanedicarboxylic acid. (C) A fluorine-based macromonomer having a polymerizable unsaturated functional group at the terminal.

9. A coating agent containing the fluorine-based graft copolymer or a salt thereof according to any one of claims 1 to 7.

10. The coating agent according to claim 9, further containing a crosslinking agent.

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