Coating composition and laminate

Abstract

To provide a water-based coating composition that has silicone slidability effectively imparted thereto, while maintaining transparency and glossiness, and a laminate having a coating layer composed of the composition.SOLUTION: This invention provides a coating composition comprising: (A) an emulsion of a resin with film-forming capabilities, selected from urethane resins, acrylic resins, and vinyl chloride resins: 100 pts.mass of solid components; and (B) a silicone-acrylic graft copolymer resin: 5 to 70 pts.mass, having a median particle size of 8 to 150 μm, which is a copolymer of polyorganosiloxane having a mercapto group, an acryloxy group or a methacryloxy group with at least one monomer selected from acrylate and methacrylate monomers, where the mass ratio of acrylate units and methacrylate units to the polyorganosiloxane is between 30:70 and 99:1.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a coating composition. Specifically, the present invention relates to an aqueous coating composition that can impart gloss and sliding properties to a substrate surface while maintaining transparency. The present invention also relates to a laminate having a film formed thereon using the coating composition. [Background technology]

[0002] In recent years, in the field of coating agents, there has been a shift in dispersion media from organic solvents to water-based systems due to environmental concerns. Emulsions of urethane resins, acrylic resins, vinyl chloride, etc. have excellent film-forming properties and have been widely used as coating agents.

[0003] Silicone resins are known to be capable of imparting slidability to substrates, but when used as coating agents, they can cause problems such as whitening of the coating film.

[0004] Therefore, attempts have been made to use a method in which an emulsion of a film-forming urethane resin, acrylic resin, or vinyl chloride resin is mixed with a silicone resin as a coating agent. However, the mixing does not fully exhibit the sliding properties of the silicone resin, and the performance of the urethane resin, acrylic resin, and vinyl chloride resin is deteriorated, resulting in unsatisfactory performance.

[0005] Japanese Patent Laid-Open No. 2013-67787 (Patent Document 1) discloses that a coating agent made by mixing an emulsion of a urethane, acrylic, or vinyl chloride resin with a silicone resin can impart water repellency to a substrate. However, there is room for improvement in terms of sliding properties and transparency of the coating film.

[0006] Japanese Patent Laid-Open No. 2020-55938 (Patent Document 2) discloses a coating agent containing a urethane emulsion and a silicone acrylic resin emulsion. However, although the transparency of the coating film is improved, the use of the silicone acrylic resin emulsion causes the coating film to lose its gloss, making it unsuitable as a coating agent for applications requiring gloss. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-67787 [Patent Document 2] Japanese Patent Application Publication No. 2020-55938 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above circumstances, and aims to provide an aqueous coating composition that, when mixed with an emulsion of a resin selected from urethane resins, acrylic resins, and vinyl chloride resins, effectively imparts the sliding properties of silicone while maintaining transparency and gloss, and a laminate having a coating made of said composition. [Means for solving the problem]

[0009] As a result of extensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned problems can be solved by a coating composition comprising an emulsion of a film-forming resin selected from a urethane resin, an acrylic resin, or a vinyl chloride resin, blended in a predetermined ratio with a powder of a silicone acrylic graft copolymer resin having a specific median particle size (50% particle size), and have thus completed the present invention.

[0010] Accordingly, the present invention provides the following coating composition. (A) an emulsion of a resin having film-forming ability selected from a urethane resin, an acrylic resin, and a vinyl chloride resin: 100 parts by mass in terms of solid content, and (B) 5 to 70 parts by mass of a silicone acrylic graft copolymer resin, which is a copolymer of a polyorganosiloxane represented by the following general formula (1) and at least one monomer selected from an acrylic ester monomer and a methacrylic ester monomer, wherein the mass ratio of the acrylic ester unit and the methacrylic ester unit to the polyorganosiloxane is 30:70 to 99:1 and the resin has a median diameter of 8 to 150 μm: A coating composition comprising [ka] (In the formula, R 1 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 2 is a mercapto group, an alkyl group having 1 to 6 carbon atoms having an acryloxy group or a methacryloxy group, or a vinyl group; X is each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group; Y is X or -[O-Si(X)2] d -X, which may be the same or different groups, and the above formula (1) has at least two silicon-bonded hydroxyl groups or alkoxy groups, Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, a is an integer from 0 to 1,000, b is a positive number from 100 to 10,000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1,000. However, the bonding order of each siloxane unit in the above formula (1) is not limited to the above. Furthermore, the present invention provides the coating agent composition as described above, which further has at least one constituent feature selected from the following [1] to [5]. [1] In the above general formula (1), R 1 and X are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. [2] X and Y in the above general formula (1), and the above -[O-Si(X)2] d The coating composition as described above, wherein at least two of the X's in -X are hydroxyl groups or alkoxy groups. [3] (B) The coating composition, wherein the silicone acrylic graft copolymer resin has a median diameter of 10 to 130 μm. [4] (B) silicone acrylic graft copolymer resin, (b1) a polyorganosiloxane represented by the general formula (1), (b2) an acrylic acid ester monomer or a methacrylic acid ester monomer; Optionally, (b3) a functional group-containing monomer copolymerizable with the (b2) component; The coating composition is a copolymer of the above. [5] The coating composition, wherein in a laminate having a substrate and a coating film made of the coating composition, the haze value of the coating film has an increase rate of 2000% or less compared to the haze value of the surface of the substrate not having the coating film.

[0011] The present invention further provides a laminate comprising a substrate and a coating made of the coating composition, the coating being formed on one or both sides of the substrate. Furthermore, the present invention provides the above laminate, which further has at least one constituent feature selected from the following [i] to [v]. [i] The laminate as described above, wherein the substrate is a plastic selected from polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, polyester, cellulose, diethylene glycol bisallyl carbonate polymer, acrylonitrile-butadiene-styrene polymer, poly(meth)acrylic acid ester, polyurethane, and epoxy resin. [ii] The laminate as described above, wherein the substrate is a glass selected from soda-lime glass, quartz glass, lead glass, borosilicate glass, and alkali-free glass. [iii] The laminate, wherein the substrate is wood selected from the family Maple, Birch, Lauraceae, Chestnut, Scrophulariaceae, Araucaria, Ulmaceae, Bignoniaceae, Rosaceae, Cupressaceae, Dipterocarpaceae, Myrtaceae, Fagaceae, Pinaceae, Fabaceae, and Oleaceae. [iv] The laminate as described above, wherein the substrate is a fiber selected from cotton, hemp, linen, wool, silk, cashmere, asbestos, polyamide, polyester, viscose, cellulose, glass, and carbon. [v] The laminate, wherein the thickness of the coating is 1 to 500 μm.

[0012] The present invention further provides a powder of a silicone acrylic graft copolymer resin having a median diameter (D50) of 8 to 150 μm, wherein the silicone acrylic graft copolymer is a copolymer of a polyorganosiloxane represented by the above general formula (1) with at least one monomer selected from an acrylic ester monomer and a methacrylic ester monomer, and the mass ratio of the acrylic ester units and the methacrylic ester units to the polyorganosiloxane is 30:70 to 99:1. The powder preferably further has at least one constituent feature selected from the above [1] to [4]. More preferably, the present invention provides a powder for a coating agent made of the silicone acrylic graft copolymer resin, and a coating agent containing a powder of the silicone acrylic graft copolymer resin. [Effects of the Invention]

[0013] The coating composition of the present invention has gloss and sliding properties while maintaining excellent transparency, and can maintain high abrasion resistance without impairing the appearance of a laminate on which a film made of the coating composition is formed.Furthermore, since it is aqueous, it has great advantages in terms of workability and the environment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention provides a coating composition comprising: (A) 100 parts by mass (solids) of an emulsion of a film-forming resin selected from urethane resins, acrylic resins, and vinyl chloride resins; and (B) 5 to 70 parts by mass of a silicone acrylic graft copolymer resin, which is a copolymer of a polyorganosiloxane represented by the following general formula (1) and at least one monomer selected from acrylic ester monomers and methacrylic ester monomers, wherein the mass ratio of acrylic ester units to methacrylic ester units relative to the polyorganosiloxane is 30:70 to 99:1 and the median diameter is 10 to 150 μm. The coating composition comprises the silicone acrylic graft copolymer resin dispersed in the film-forming resin emulsion. More preferably, the coating composition has a haze value of the coating film in a laminate having a substrate and a coating film made of the coating composition, which increases by 2000% or less compared to the haze value of the surface of the substrate not having the coating film.

[0015] (A) The film-forming resin emulsion selected from urethane, acrylic, and vinyl chloride emulsions may be synthesized by known methods, such as emulsion polymerization using anionic or nonionic emulsifiers, or may be commercially available. Film-forming ability refers to the ability to eliminate particle-like properties on the coating surface after drying at a certain temperature or higher and to prevent fine cracks from forming during drying. The drying temperature range for film formation is not particularly limited, but is preferably 30 to 150°C, more preferably 100 to 150°C.

[0016] Examples of the resin include urethane-based resin emulsions, acrylic-based resin emulsions using (meth)acrylic monomers such as (meth)acrylic acid and (meth)acrylic acid esters, and vinyl chloride-based resin emulsions using vinyl chloride, vinyl chloride / vinyl acetate, vinyl chloride / (meth)acrylic acid, or esters thereof. Examples of (meth)acrylic monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, and crotonic acid. For these resin emulsions to have film-forming ability, the particle size is 10 to 750 nm, preferably 10 to 500 nm, and more preferably 20 to 200 nm. The glass transition temperature (hereinafter sometimes referred to as Tg) is 120°C or lower, preferably 60°C or lower, and even more preferably 30°C or lower. The lower limit of the glass transition temperature is preferably -50°C.

[0017] The glass transition temperature Tg is calculated using the following formula: (Pa+Pb+Pc) / Tg=(Pa / Ta)+(Pb / Tb)+(Pc / Tc) In the formula, Tg represents the glass transition temperature (K) of the polymer particles, Pa, Pb, and Pc represent the contents (mass%) of monomers a, b, and c, respectively, and Ta, Tb, and Tc represent the glass transition temperatures (K) of the homopolymers of monomers a, b, and c, respectively. The glass transition temperatures can be measured in accordance with JIS K7121.

[0018] Examples of urethane resin emulsions include various water-soluble urethane resins that are reaction products of polyisocyanate and polyol, with the polyol being polyether, polycarbonate, polyester, or the like. For this urethane resin emulsion to have film-forming ability, the particle size is 10 to 750 nm, preferably 10 to 500 nm, and more preferably 20 to 200 nm. The viscosity (25°C) should be 10 to 500 mPa·s. The glass transition temperature is 120°C or lower, preferably 60°C or lower, and more preferably 30°C or lower. The lower limit of the glass transition temperature is preferably −50°C. The glass transition temperature can be measured according to JIS K7121.

[0019] Commercially available polyether-based urethane resin emulsions include Adeka Bontiter HUX-350 manufactured by Adeka Corporation, WLS-201 and WLS-202 manufactured by DIC Corporation, and Superflex E-4000 and E-4800 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Examples of polycarbonate-based urethane resin emulsions include Hydran WLS-210 and WLS-213 manufactured by DIC Corporation, UW-1005E and UW-5502 manufactured by Ube Industries, Ltd., Permarin UA-368 manufactured by Sanyo Chemical Industries, Ltd., and Superflex 460 and Superflex 470 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Examples of polyester-based urethane resin emulsions include Adeka Bontiter HUX-380 and HUX-540 manufactured by Adeka Corporation, and Superflex 420 and Superflex 860 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0020] Examples of commercially available acrylic resin emulsions include Vinyblan manufactured by Nissin Chemical Industry Co., Ltd., Yodozole manufactured by Henkel Japan Co., Ltd., and Aron manufactured by Toagosei Co., Ltd. An example of a commercially available vinyl chloride resin emulsion is Vinyblan manufactured by Nissin Chemical Industry Co., Ltd.

[0021] The preferred film-forming resin emulsion varies depending on the substrate used, but when used for applications such as synthetic leather, a urethane-based resin emulsion is preferred.

[0022] The amount of resin emulsion capable of forming a film is 60 to 99 mass % in terms of solid content, and preferably 65 to 95 mass % relative to the total solid content in the coating composition (100%). If the amount of resin emulsion is less than the lower limit, there is a problem that the film properties such as abrasion resistance become very poor, while if the amount exceeds the upper limit, there is a problem that the surface is not smooth and the feel is poor.

[0023] The silicone acrylic graft copolymer resin of component (B) is preferably a copolymer obtained by emulsion graft polymerization of a mixture of (b1) a polyorganosiloxane represented by the following general formula (1), (b2) a (meth)acrylic acid ester monomer, and optionally (b3) a functional group-containing monomer copolymerizable with component (b2), followed by drying.

[0024] The silicone acrylic graft copolymer resin (B) is preferably obtained by using 1 to 233 parts by mass of the component (b2) and 0.01 to 20 parts by mass of the optional component (b3) per 100 parts by mass of the component (b1). More preferably, the amount of the component (b2) is 5.3 to 144 parts by mass, more preferably 8.7 to 66.7 parts by mass, and the amount of the optional component (b3) is 0.01 to 5 parts by mass per 100 parts by mass of the component (b1).

[0025] (b1) Polyorganosiloxane is represented by the following general formula (1). [ka] In the formula, R 1 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 2 is a mercapto group, an alkyl group having 1 to 6 carbon atoms having an acryloxy group or a methacryloxy group, or a vinyl group; X is each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group; Y is X or -[O-Si(X)2] d-X, which may be the same or different, and the formula (1) has at least two silicon atom-bonded hydroxyl groups or alkoxy groups, Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, a is an integer of 0 to 1,000, b is a positive number of 100 to 10,000, c is a positive number of 1 to 10, and d is a positive number of 1 to 1,000. In the above formula (1), the bonding order of the siloxane units is not limited to the above, and the siloxane units may form block units or may be bonded randomly.

[0026] In the above formula, R 1 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and are preferably a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. Examples of such groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl, tolyl, and naphthyl groups; alkenylaryl groups such as vinylphenyl groups; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and alkenylaralkyl groups such as vinylbenzyl and vinylphenylpropyl groups, as well as groups in which some or all of the hydrogen atoms have been substituted with halogen atoms such as fluorine, bromine, and chlorine, acryloxy, methacryloxy, carboxyl, alkoxy, alkenyloxy, amino, alkyl-, alkoxy-, or (meth)acryloxy-substituted amino groups. 1 is preferably a methyl group.

[0027] R 2 is a mercapto group, an acryloxy group or methacryloxy group-substituted alkyl group having 1 to 6 carbon atoms, or a vinyl group. For example, a mercaptopropyl group, an acryloxypropyl group, a methacryloxypropyl group, a vinyl group, etc. are preferred.

[0028] X's are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group. The unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms is, for example, R 1 Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a tetradecyloxy group. X is preferably a hydroxyl group, a methyl group, a butyl group, a phenyl group, or a methoxy group.

[0029] Y's are each independently X or -[O-Si(X)2] d It is a group represented by -X, and d is a positive number of 1 to 1,000, preferably a positive number of 1 to 200.

[0030] Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, and is preferably a hydroxyl group or a methyl group.

[0031] In the above formula (1), if a is greater than 1,000, the strength of the resulting coating will be insufficient. a is an integer from 0 to 1,000, preferably 0 or a positive number from 1 to 200. If b is less than 100, the flexibility of the coating will be poor, and if it is greater than 10,000, the tear strength of the coating will be reduced. Therefore, b is a positive number from 100 to 10,000, preferably a positive number from 1,000 to 5,000. c is a positive number from 1 to 10, preferably a positive number from 1 to 6. If c is greater than 10, the abrasion resistance of the substrate may not be improved when coated with the composition. d is a positive number from 1 to 1,000, preferably a positive number from 1 to 200. Furthermore, from the viewpoint of crosslinkability, the above formula (1) should have at least two, preferably two to four, silicon-bonded hydroxyl or alkoxy groups per molecule. Preferably, the group represented by X or Y in the formula (1) has at least two silicon-bonded hydroxyl groups or alkoxy groups. More preferably, X and Y in the formula (1) and the -[O-Si(X)2] d At least two of the X's in -X are preferably hydroxyl groups or alkoxy groups. More preferably, at least two, preferably two to four, of the X's at both ends in the above formula (1) are hydroxyl groups or alkoxy groups. The alkoxy groups are preferably alkoxy groups having 1 to 4 carbon atoms, more preferably methoxy groups. More preferred are compounds having silicon-bonded hydroxyl groups at both ends.

[0032] The polyorganosiloxane (b1) is preferably used in the form of an emulsion, and may be a commercially available product or may be synthesized. When synthesizing, a known emulsion polymerization method may be used. For example, polyorganosiloxanes can be easily synthesized by emulsifying and dispersing a cyclic organosiloxane, an α,ω-dihydroxysiloxane oligomer, an α,ω-dialkoxysiloxane oligomer, an alkoxysilane, or the like, which may have fluorine atoms, (meth)acryloxy groups, carboxyl groups, hydroxyl groups, or amino groups, and a silane coupling agent represented by the following general formula (2) in water using an anionic surfactant, and then adding a catalyst such as an acid as necessary to carry out a polymerization reaction. R 3 (4-e-f) R 4 f Si(OR 5 ) e (2) In the above formula (2), R 3 R is a monovalent organic group having a polymerizable double bond, and in particular an alkyl group having 1 to 6 carbon atoms substituted with an acryloxy group or a methacryloxy group. 4 is an alkyl group having 1 to 4 carbon atoms, and R 5 is an alkyl group having 1 to 4 carbon atoms, e is 2 or 3, f is 0 or 1, and e+f=2 or 3.

[0033] Examples of the cyclic organosiloxane include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), 1,1-diethylhexamethylcyclotetrasiloxane, phenylheptamethylcyclotetrasiloxane, 1,1-diphenylhexamethylcyclotetrasiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7-tetracyclohexyltetramethylcyclotetrasiloxane, tris(3,3,3-trifluoropropyl)trimethylcyclotrisiloxane, and 1,3,5,7-tetra(3-methacryloxypropyl)tetramethylsiloxane. Examples include chlorotetrasiloxane, 1,3,5,7-tetra(3-acryloxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(3-carboxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(3-vinyloxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(p-vinylphenyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra[3-(p-vinylphenyl)propyl]tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(N-acryloyl-N-methyl-3-aminopropyl)tetramethylcyclotetrasiloxane, and 1,3,5,7-tetra(N,N-bis(lauroyl)-3-aminopropyl)tetramethylcyclotetrasiloxane. Octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane are preferably used.

[0034] Examples of the silane coupling agent include vinyl silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrippropoxysilane, vinyltriisopropoxysilane, vinylmethyldimethoxysilane, and vinylmethyldiethoxysilane; γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropyltripropoxysilane, γ-(meth)acryloxypropyltriisopropoxysilane, and γ-(meth)acryloxypropyltriisopropoxysilane; Examples of suitable silane coupling agents include acrylic silanes such as γ-(meth)acryloxypropyl tributoxysilane, γ-(meth)acryloxypropyl methyldimethoxysilane, γ-(meth)acryloxypropyl methyldiethoxysilane, γ-(meth)acryloxypropyl methyldipropoxysilane, γ-(meth)acryloxypropyl methyldiisopropoxysilane, and γ-(meth)acryloxypropyl methyldibutoxysilane; and mercaptosilanes such as γ-mercaptopropyl methyldimethoxysilane and γ-mercaptopropyl trimethoxysilane. Oligomers obtained by condensation polymerization of these silane coupling agents may be more preferred because they suppress the generation of alcohol. Here, (meth)acryloxy refers to acryloxy or methacryloxy. The amount of the silane coupling agent is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the cyclic organosiloxane. If the amount of the silane coupling agent is less than 0.01 parts by mass, the transparency of the coating agent may decrease, whereas if the amount of the silane coupling agent is more than 10 parts by mass, the coating agent may not exhibit sufficient sliding properties.

[0035] By copolymerizing the above-mentioned cyclic organosiloxane or the like with the silane coupling agent represented by the above general formula (2), the following (R 2 A polyorganosiloxane having (Z)SiO units and represented by the following formula (1) is obtained, and the effect of grafting the monomer of component (b2) or (b3) is obtained. [ka]

[0036] Known polymerization catalysts may be used as the polymerization catalyst. Among these, strong acids are preferred, such as hydrochloric acid, sulfuric acid, dodecylbenzenesulfonic acid, citric acid, lactic acid, and ascorbic acid. Dodecylbenzenesulfonic acid, which has emulsifying properties, is preferred. The amount of acid catalyst added is preferably 0.01 to 10 parts by mass, more preferably 0.2 to 2 parts by mass, per 100 parts by mass of the cyclic organosiloxane.

[0037] Examples of surfactants used in polymerization include anionic surfactants such as sodium lauryl sulfate, sodium laureth sulfate, N-acylamino acid salts, N-acyltaurate salts, aliphatic soaps, and alkyl phosphates. Among these, those that are easily soluble in water and do not have a polyethylene oxide chain are preferred. N-acylamino acid salts, N-acyltaurate salts, aliphatic soaps, and alkyl phosphates are more preferred. Sodium lauroyl methyl taurate, sodium myristoyl methyl taurate, and sodium lauryl sulfate are particularly preferred. The amount of the anionic surfactant is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the cyclic organosiloxane.

[0038] The polymerization temperature is preferably 50 to 75° C., and the polymerization time is preferably 10 hours or more, more preferably 15 hours or more. Furthermore, it is particularly preferable to age the mixture after polymerization at 5 to 30° C. for 10 hours or more.

[0039] The (b2) acrylic acid ester or methacrylic acid ester (hereinafter sometimes referred to as the acrylic component) used in the present invention refers to an acrylic acid ester monomer or methacrylic acid ester monomer that does not have a functional group such as a hydroxyl group, an amide group, or a carboxyl group. An acrylic acid ester or methacrylic acid ester having an alkyl group having 1 to 10 carbon atoms is preferred. Furthermore, a monomer that provides an acrylic component polymer with a glass transition temperature (hereinafter sometimes referred to as Tg) of 40°C or higher, preferably 60°C or higher, is preferred. Examples of such a monomer include methyl methacrylate, isopropyl methacrylate, ethyl methacrylate, and cyclohexyl methacrylate. Monomers with low Tg, such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate, can be used in combination with monomers with high Tg. The upper limit of Tg is preferably 200°C or lower, more preferably 150°C or lower. The glass transition temperature can be measured according to JIS K7121.

[0040] The functional group-containing monomer (b3) copolymerizable with the component (b2) is a monomer having an unsaturated bond, such as a carboxyl group, an amide group, a hydroxyl group, a vinyl group, or an allyl group. Examples of such monomers include methacrylic acid, acrylic acid, acrylamide, allyl methacrylate, vinyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. By copolymerizing these monomers, compatibility can be improved.

[0041] The silicone acrylic graft copolymer resin emulsion (B) of the present invention is prepared by emulsion graft polymerizing the polyorganosiloxane (b1) obtained as described above with a mixture of a (b2) (meth)acrylic acid ester monomer and a (b3) monomer containing a functional group copolymerizable with the component (b2).

[0042] The mass ratio of the polyorganosiloxane of formula (1) to the (meth)acrylic acid ester monomer during graft polymerization (mass ratio of the polyorganosiloxane of formula (1) to the (meth)acrylic unit) is 30:70 to 99:1, preferably 45:65 to 95:5, and more preferably 60:40 to 92:8. If the silicone component is less than the lower limit, there is a problem in that the abrasion resistance does not improve when coated.

[0043] A radical initiator may be used in the reaction. Examples of the radical initiator include persulfates such as potassium persulfate and ammonium persulfate, aqueous hydrogen persulfate, t-butyl hydroperoxide, and hydrogen peroxide. If necessary, a redox system using a reducing agent such as sodium sulfite, Rongalite, L-ascorbic acid, tartaric acid, sugars, or amines can also be used.

[0044] The surfactant contained in the polyorganosiloxane emulsion described above is sufficient for graft polymerization, but to improve stability, anionic surfactants such as sodium lauryl sulfate, sodium laureth sulfate, N-acylamino acid salts, N-acyltaurine salts, aliphatic soaps, and alkyl phosphates can be added. Nonionic emulsifiers such as polyoxyethylene lauryl ether and polyoxyethylene tridecyl ether can also be added.

[0045] The graft polymerization temperature of components (b2) and (b3) to component (b1) is preferably 25 to 55° C., more preferably 25 to 40° C. The polymerization time is preferably 2 to 8 hours, more preferably 3 to 6 hours.

[0046] Furthermore, a chain transfer agent can be added to adjust the molecular weight and graft rate of the graft polymer.

[0047] The silicone acrylic graft copolymer resin emulsion obtained as described above is a polymer in which components (b2) and (b3) are randomly grafted to component (b1).

[0048] The solids content of the silicone acrylic graft copolymer resin emulsion of the present invention is preferably 35 to 50% by mass. The viscosity (25°C) is preferably 500 mPa·s or less, more preferably 50 to 500 mPa·s. The viscosity can be measured using a rotational viscometer. The median diameter of the dispersed particles in the emulsion is 180 nm or less, preferably 50 to 180 nm, and more preferably 80 to 170 nm. If the median diameter is too large, a transparent coating agent cannot be obtained, while if the median diameter is too small, there is a problem of reduced dispersibility. The median diameter of the dispersed particles is a volume-based particle size that can be measured using a laser diffraction / scattering particle size distribution analyzer.

[0049] The silicone acrylic graft copolymer emulsion of the present invention is prepared by concentrating the dispersion, for example, by methods such as thermal dehydration, filtration, centrifugation, or decantation, followed by washing with water as necessary, and then removing moisture by methods such as thermal drying under normal or reduced pressure, spray drying in which the dispersion is sprayed into an air stream, or thermal drying using a fluidized heat medium, followed by drying and powdering. The drying temperature is preferably 40 to 105°C. If the obtained powder is slightly agglomerated, it may be crushed using a suitable grinder such as a jet mill, ball mill, or hammer mill.

[0050] The resulting silicone-acrylic graft copolymer resin may be washed to remove any residual cyclic organosiloxane and surfactant. The solvent used for washing is preferably an alcohol-based organic solvent or a hydrocarbon-based organic solvent, such as a lower alcohol having 1 to 4 carbon atoms or an aliphatic hydrocarbon having 5 to 20 carbon atoms. Methanol, ethanol, isopropyl alcohol, hexane, or isododecane is particularly preferred. While the washing method is not particularly limited, for example, 100 parts by mass of the powder is placed in a beaker, and the solvent is added in an amount equal to or greater than 5 times the mass of the powder. The mixture is stirred for several hours and then filtered by suction. It is more effective to then wash the powder with the same solvent or with a water-soluble solvent such as an alcohol-based solvent. Washing is typically performed at room temperature (25°C), but heating may be used if necessary.

[0051] If washed, it is dried again to form a powder, but the filtered powder may simply be dried in a dryer at a temperature of 40 to 105°C for several hours, or a fluidized bed dryer may be used.

[0052] The silicone acrylic graft copolymer resin (B) obtained by drying in the above manner preferably has a volumetric median diameter of 8 to 150 μm, preferably 10 to 130 μm, more preferably 40 to 120 μm, and particularly preferably 50 to 100 μm. The median diameter can be measured using a laser diffraction / scattering particle size distribution analyzer with methanol or the like as a dispersion medium.

[0053] The present invention is characterized by an emulsion containing powder of a silicone acrylic graft copolymer resin having the above median diameter. By mixing this resin with the above-mentioned emulsion of film-forming resin (A), a coating composition is provided that effectively imparts the sliding properties of silicone while maintaining transparency and gloss. While silica and other silicone-based resins can partially aggregate, causing streaks and clumps during coating, the present invention uses fine particles of silicone acrylic graft copolymer resin (B) with good surface properties, and their compatibility and dispersibility with the emulsion of film-forming resin (A) enable the production of a uniform coating film.

[0054] The weight-average molecular weight of the silicone acrylic graft copolymer resin is preferably 50,000 to 500,000. If it is less than 50,000, precipitation on the surface of the rubber compound may become severe, and if it exceeds 500,000, the friction reduction effect may be insufficient. The weight-average molecular weight is measured by mixing the emulsion with isopropyl alcohol (IPA), extracting and drying the oil, and then dissolving 1 g of the mixture in 100 mL of toluene, and converting it into dimethyl silicone molecular weight from the kinematic viscosity measured at 25°C.

[0055] The amount of silicone acrylic graft copolymer resin (component (B)) blended in the coating composition is 1 to 40 mass % on a solids basis, preferably 1 to 35 mass %, and more preferably 2 to 15 mass %. If the amount of silicone acrylic graft copolymer resin emulsion is less than the lower limit, there is a problem in that no improvement in abrasion resistance is observed, whereas if the amount is more than the upper limit, there is a problem in that whitening occurs and abrasion resistance also decreases. The blending ratio of the film-forming resin emulsion (A) and the silicone acrylic graft copolymer resin (B) may be such that, in terms of solid content, the amount of component (B) is 5 to 70 parts by mass, preferably 8 to 50 parts by mass, and more preferably 10 to 25 parts by mass, per 100 parts by mass of component (A).

[0056] The coating composition of the present invention can be obtained by mixing (A) a film-forming resin emulsion with (B) a silicone acrylic graft copolymer resin, preferably in an aqueous system, by a known mixing and preparation method (1000 to 5000 rpm) using a propeller stirrer, homogenizer, or the like, to disperse (B) the silicone acrylic graft copolymer resin.

[0057] Furthermore, the coating composition of the present invention may contain additives such as antioxidants, colorants, ultraviolet absorbers, light stabilizers, antistatic agents, plasticizers, flame retardants, thickeners, surfactants, organic solvents such as film-forming aids, other resins, etc., within the range that does not affect the performance.

[0058] In order to ensure the desired high transparency, the coating composition of the present invention preferably exhibits an increase in haze of 0% to 2000% relative to the haze value of the substrate before application, and more preferably 0% to 1800%, depending on the type of substrate. The "haze" referred to in the present invention is haze calculated from the total luminous transmittance and diffuse transmittance according to the following formula in accordance with JIS K7136 (2000). HAZE (Haze) = (Diffuse transmittance T d / Total light transmittance T t )×100 (%) The haze value of the coating applied to the substrate can be measured, for example, using a haze meter manufactured by Nippon Denshoku Industries Co., Ltd. The haze value of the substrate before the coating composition is applied can also be measured according to the same standard as above. In addition, the "haze increase rate" referred to in the present invention is calculated by the following equation, where X is the haze value of the substrate and Y is the haze value after the coating composition is applied: [Haze increase rate (%)] = [(Y - X) / X] × 100 It can be expressed as:

[0059] The coating composition of the present invention obtained in this manner can be applied to one or both surfaces of a substrate, such as plastics (PET, PI, synthetic leather, etc.), glass (general-purpose glass, SiO, etc.), metals (Si, Cu, Fe, Ni, Co, Au, Ag, Ti, Al, Zn, Sn, Zr, and alloys thereof, etc.), wood, fibers (cloth, thread, etc.), paper, or ceramics (fired oxides, carbides, nitrides, etc.), by immersion or coating, followed by drying (room temperature to 150°C), imparting the long-term benefits of silicone resin, such as water repellency, weather resistance, heat resistance, cold resistance, gas permeability, and tribological properties, while maintaining the advantages of resin. This is believed to be due to the formation of a robust sea-island structure between the film-forming resin and the curable silicone resin.

[0060] Examples of plastic substrates include poly(meth)acrylic acid esters such as polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, polyester, cellulose, diethylene glycol bisallyl carbonate polymers, acrylonitrile-butadiene-styrene polymers, polyurethane, and epoxy resins. Examples of plastic processed products include automotive interior materials, organic glass, electrical and building materials, building exterior materials, optical films used in liquid crystal displays, light-diffusing films, mobile phones, and home appliances. Drying methods include leaving the substrate at room temperature for 1 to 10 days, but from the perspective of rapidly promoting curing, heating at a temperature of 20 to 150°C for 1 second to 10 hours is preferred. Furthermore, when the plastic substrate is made of a material that is prone to deformation or discoloration due to heating, drying at a relatively low temperature of 20 to 100°C is preferred.

[0061] Examples of glass substrates that can be used include soda-lime glass, quartz glass, lead glass, borosilicate glass, and alkali-free glass. Glass processed products include architectural plate glass, glass for vehicles such as automobiles, glass for lenses, glass for mirrors, glass for display panels, and glass for solar cell modules. Drying is preferably performed by leaving the glass at room temperature for about 1 to 10 days, or by heating the glass at a temperature of 20 to 150°C, particularly 60 to 150°C, for 1 second to 10 hours.

[0062] Examples of wood substrates include wood from the families Maple, Birch, Lauraceae, Chestnut, Scrophulariaceae, Araucaria, Ulmaceae, Bignoniaceae, Rosaceae, Cupressaceae, Dipterocarpaceae, Myrtaceae, Fagaceae, Pinaceae, Fabaceae, and Oleaceae. Wood products include processed and molded products made from wood itself, plywood and laminated lumber, processed and molded products thereof, and combinations thereof. Examples include building materials, including exterior and interior materials for buildings, furniture such as desks, wooden toys, and musical instruments. Hot air drying at 20 to 150°C, particularly 50 to 150°C, for 0.5 to 5 hours is preferred. Furthermore, discoloration of the coating film can be avoided by keeping the drying temperature below 120°C.

[0063] Examples of fiber substrates include natural fibers such as cotton, hemp, linen, wool, silk, cashmere, and asbestos, and chemical fibers such as polyamide, polyester, viscose, cellulose, glass, and carbon. Fiber processed products include all types of woven fabrics, knitted fabrics, and nonwoven fabrics, as well as films and papers. Drying methods include leaving the material at room temperature for 10 minutes to several tens of hours, or drying at a temperature of 20 to 150°C for 0.5 minutes to 5 hours.

[0064] The method for coating the coating composition of the present invention onto a substrate is not particularly limited, and examples thereof include application methods using various coaters such as a gravure coater, a bar coater, a blade coater, a roll coater, an air knife coater, a screen coater, a curtain coater, and brush coating; spray application; and immersion.

[0065] The amount of the coating composition of the present invention to be applied to a substrate is not particularly limited, but is usually, in terms of antifouling properties, application workability, etc., preferably 1 to 300 g / m in terms of solid content. 2 , more preferably 5 to 100 g / m 2 The thickness of the resulting film is preferably in the range of 1 to 500 μm, and more preferably 5 to 100 μm. The film may be formed by natural drying or by heating and drying at 100 to 200° C. [Example]

[0066] The present invention will be described in more detail below with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. In the following Examples, parts and % represent parts by mass and % by mass, respectively. In addition, in the structural formula of the organopolysiloxane shown below, the bonding order of the siloxane units is not limited to the following.

[0067] [Manufacturing Example 1] A solution of 600g of octamethylcyclotetrasiloxane, 0.6g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The mixture was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and subjected to a polymerization reaction at 50-70°C for 24 hours. After this, the emulsion was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. The resulting silicone emulsion had a non-volatile content of 45.8% after drying at 105°C for 3 hours, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group. To 1200 g of the silicone emulsion obtained above, 227 g of methyl methacrylate (MMA) and 4.6 g of hydroxyethyl methacrylate (2-HEMA) were added dropwise over 3 to 5 hours while carrying out a redox reaction with peroxide and a reducing agent at 30°C, resulting in an emulsion of silicone-acrylic graft copolymerized with silicone, with a non-volatile content of 45.0%. The emulsion was spray-dried at 135°C to obtain a silicone resin powder with a median diameter of 69.9 μm (Production Example 1).

[0068] [Manufacturing Example 2] A solution of 600g of octamethylcyclotetrasiloxane, 0.5g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate dissolved in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid dissolved in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The emulsion was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and subjected to a polymerization reaction at 50-70°C for 24 hours. After this, the emulsion was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. After drying for 3 hours at 105°C, this silicone emulsion had a non-volatile content of 46.0%, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group.

[0069] To the silicone emulsion obtained above, 227 g of methyl methacrylate (MMA) and 4.6 g of hydroxyethyl methacrylate (2-HEMA) were added dropwise over 3 to 5 hours while a redox reaction was carried out with peroxide and a reducing agent at 30°C, resulting in an emulsion of silicone-acrylic graft copolymer resin with a nonvolatile content of 45.6%. This emulsion was spray-dried at 115°C to obtain a silicone resin powder with a median diameter of 12.2 μm (Production Example 2).

[0070] [Manufacturing Example 3] A solution of 600g of octamethylcyclotetrasiloxane, 3g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The emulsion was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerization reaction was carried out at 50-70°C for 24 hours, after which it was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. After drying for 3 hours at 105°C, this silicone emulsion had a non-volatile content of 45.0%, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group.

[0071] To the silicone emulsion obtained above, 58.8 g of methyl methacrylate (MMA) and 1.2 g of hydroxyethyl methacrylate (2-HEMA) were added dropwise over 3 to 5 hours while a redox reaction was carried out with peroxide and a reducing agent at 30°C, resulting in an emulsion of silicone-acrylic graft copolymer resin with a nonvolatile content of 44.5%. This emulsion was spray-dried at 135°C to obtain a silicone resin powder with a median diameter of 92.1 μm (Production Example 3).

[0072] [Manufacturing Example 4] A solution of 600g of octamethylcyclotetrasiloxane, 3g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The emulsion was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerization reaction was carried out at 50-70°C for 24 hours, after which it was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. After drying for 3 hours at 105°C, this silicone emulsion had a non-volatile content of 45.0%, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group.

[0073] To the silicone emulsion obtained above, 529.6 g of methyl methacrylate (MMA) and 10.8 g of hydroxyethyl methacrylate (2-HEMA) were added dropwise over 3 to 5 hours while a redox reaction was carried out with peroxide and a reducing agent at 30°C, resulting in an emulsion of silicone-acrylic graft copolymer resin with a nonvolatile content of 45.3%. This emulsion was spray-dried at 135°C to obtain a silicone resin powder with a median diameter of 43.3 μm (Production Example 4).

[0074] [Manufacturing Example 5] A solution of 600g of octamethylcyclotetrasiloxane, 3g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The emulsion was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerization reaction was carried out at 50-70°C for 24 hours, after which it was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. After drying for 3 hours at 105°C, this silicone emulsion had a non-volatile content of 45.0%, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group.

[0075] To the silicone emulsion obtained above, 358.2 g of methyl methacrylate (MMA) and 182.1 g of butyl acrylate (BA) were added dropwise over 3 to 5 hours while a redox reaction was carried out with the peroxide and reducing agent at 30°C, resulting in an acrylic graft copolymerization of the silicone to the silicone, yielding a silicone acrylic graft copolymer resin emulsion with a non-volatile content of 45.6%. This emulsion was spray-dried at 135°C to yield a powdered silicone resin with a median diameter of 58.0 μm (Production Example 5).

[0076] [Comparative Manufacturing Example 1] A solution of 600g of octamethylcyclotetrasiloxane, 0.6g of gamma-methacryloxypropylmethyldimethoxysilane, and 8.4g of sodium lauryl sulfate in 76g of ion-exchanged water, and a solution of 6g of dodecylbenzenesulfonic acid in 54g of pure water were placed in a 2L polyethylene beaker and emulsified uniformly using a homomixer. After that, 450g of ion-exchanged water was gradually added to dilute the mixture, and the mixture was heated under a pressure of 300kgf / cm. 2 The emulsion was passed through a high-pressure homogenizer twice at 105°C, yielding a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerization reaction was carried out at 50-70°C for 24 hours, after which it was neutralized to a pH of 6-8 with 20g of 10% aqueous sodium carbonate solution. After drying for 3 hours at 105°C, this silicone emulsion had a non-volatile content of 45.8%, and the organopolysiloxane in the emulsion was in the form of a non-flowable soft gel. The organopolysiloxane in the emulsion has the following composition: [ka] (In the above formula, R 2 is a γ-methacryloxypropyl group, and X is a hydroxyl group or a methoxy group.

[0077] To the silicone emulsion obtained above, 227 g of methyl methacrylate (MMA) and 4.6 g of hydroxyethyl methacrylate were added dropwise over 3 to 5 hours while carrying out a redox reaction with the peroxide and reducing agent at 30°C, thereby grafting acrylic onto the silicone, yielding an emulsion of silicone acrylic graft copolymer resin with a nonvolatile content of 45.0% and a median particle diameter of 232 nm (Comparative Production Example 1).

[0078] [Comparative Manufacturing Example 2] The silicone acrylic graft copolymer resin emulsion obtained in Production Example 1 was salted out by adding water and calcium chloride, and then dehydrated and dried to obtain a powdery silicone resin (Comparative Production Example 2) with a median diameter of 684 μm.

[0079] [Measurement of evaporation residue (solid concentration)] Approximately 1 g of sample was weighed onto an aluminum foil dish, placed in a dryer maintained at 105-110°C, heated for 1 hour, then removed from the dryer and allowed to cool in a desiccator. The sample was then weighed after drying and the evaporation residue was calculated using the following formula.

number

[0080] [Particle size measurement] The median diameter in the above examples and comparative examples was measured as follows. The median diameter was measured using a laser diffraction particle size analyzer (LA-950V2 manufactured by Horiba, Ltd.) In Production Examples 1 to 5, the resin refractive index was set to 1.45 and the methanol refractive index was set to 1.329, and the powders obtained in Production Examples 1 to 5 were directly added to the stirring methanol in the analyzer, and the volume-based median diameter of the resin was measured. In Comparative Production Example 1, the resin refractive index was set to 1.45 and the water refractive index to 1.333, and the silicone acrylic graft copolymer resin emulsion was directly added to the ion-exchanged water in the device while it was being stirred, and the volume-based median diameter of the emulsion particles was measured.

[0081] [Example 1] The polycarbonate-based polyurethane resin emulsion used was "Hydran WLS-213" (product name, manufactured by DIC Corporation) (viscosity 200 mPa·s (25°C), average particle size 80 nm, solids content approximately 35 wt%, Tg -15°C). While stirring the resin emulsion, Olfin PD-002W (manufactured by Nissin Chemical Industry Co., Ltd.) as a dispersant, Olfin EXP-4300 (manufactured by Nissin Chemical Industry Co., Ltd.) as a leveling agent, Adekanol UH450VF (manufactured by ADEKA Corporation) as a thickener, and the silicone acrylic graft copolymer resin obtained in Production Example 1 were added in the solids mass ratios shown in Table 2. The mixture was stirred for at least 30 minutes using a dispersing mixer, and then filtered through an 80-mesh sieve to obtain a coating composition.

[0082] [Examples 2 to 9, Comparative Examples 1 to 7] The polyether-based polyurethane resin emulsion used was "Hydran WLS-201" (viscosity 200 mPa·s (25°C), average particle size 80 nm, solid content approximately 35 wt%, Tg -15°C) manufactured by DIC Corporation. Furthermore, as a vinyl chloride-acrylic copolymer resin emulsion, Vinyblan 278 (manufactured by Nissin Chemical Industry Co., Ltd., average particle size 180 nm, solid content approximately 43 wt %, Tg 33° C.) was used. Coating compositions were obtained by repeating the method of Example 1 above, except that the blending ratios (solid mass ratios) of each component were as shown in Table 2 (Examples 2 to 9) and Table 3 (Comparative Examples 1 to 6). The raw material ratios shown in Tables 2 and 3 are mass ratios of solid content.

[0083] Coating films were formed using the coating compositions obtained in the above Examples and Comparative Examples using the following method. The resulting coating films were measured for haze value, haze increase rate, static and dynamic friction coefficients, water contact angle, and gloss. The measurement methods are as follows. The results are shown in Tables 2 and 3.

[0084] <Film formation method> PET film The coating composition of each example was applied using a bar coater and dried at 105°C for 5 minutes to form a coating film on the PET film with a dry thickness of about 10 µm.

[0085] <Haze value and light transmittance measurement> The haze value of the substrate having the coating film was measured using a product called "Haze Meter COH400" (manufactured by Nippon Denshoku Industries Co., Ltd.) The preferred range of haze value for PET film (haze value 5%) is 5.0 to 40.0%.

[0086] <Haze increase rate> The haze increase rate is calculated by the following formula. If the increase rate of the haze value is 0 to 2000%, the transparency can be judged to be high. If it is 1000% or less, the transparency is even higher and is preferable. On the other hand, if the increase in haze value exceeds 2000%, the transparency of the laminate deteriorates and it appears whitish. "Haze increase rate (%)" = [(Y - X) / X] x 100 X: Haze value of the substrate Y: Haze value after coating composition is applied

[0087] <Static and dynamic friction coefficient measurement> Using a HEIDON TYPE-38 (manufactured by Shinto Scientific Co., Ltd.), a 200 g metal indenter was brought into contact with the coating film perpendicularly and moved at a rate of 3 cm / min. The friction force was measured, and the coefficient of friction was calculated from the friction force. The preferred ranges for the static and dynamic friction coefficients of a PET film are 0.01 to 0.40 for the static friction coefficient and 0.01 to 0.20 for the dynamic friction coefficient. If the static friction coefficient exceeds 0.40 or the dynamic friction coefficient exceeds 0.20, the surface friction increases, causing snagging and deteriorating the feel, which is not preferred.

[0088] <Water contact angle> 2 μl of pure water was dropped onto the coating film, and the contact angle after 10 seconds was measured using a contact angle meter, model CA-D, manufactured by Kyowa Interface Science Co., Ltd. The preferred range for the water contact angle is 40° or more. If it is less than 40°, it will not repel water-based dirt, causing it to adhere more, resulting in a decrease in anti-fouling properties, which is not preferred.

[0089] <Glossiness> The gloss of the coating film was measured using a gloss meter PG-1M (manufactured by Nippon Denshoku Industries Co., Ltd.) and the value at 60° was read. The preferred range of gloss is 50 or more, more preferably 54 or more. If the gloss is less than 50, the surface will not be glossy and the appearance will deteriorate, which is not preferred.

[0090] The raw material composition ratios and median diameters of the silicone acrylic graft copolymer resins and emulsion resins obtained in the above Production Examples and Comparative Production Examples are summarized in Table 1 below.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] As shown in Table 3 above, the coating compositions of Comparative Examples 1 to 7 were unable to provide the coating film with good sliding properties, water repellency, or stain resistance while maintaining the transparency and gloss of the coating film. Furthermore, the coating composition of Comparative Example 3 corresponds to the coating agent containing the silicone acrylic resin emulsion described in JP 2020-55938 A (Patent Document 2). While this coating composition improved the transparency of the coating film, the gloss of the coating film was inferior to that of the coating compositions of the Examples. Furthermore, the coating composition obtained in Comparative Example 4 had a large particle diameter, which caused the components to separate in a short time, preventing the formation of a uniform coating film, making it impossible to evaluate the coating properties. On the other hand, as shown in Table 2 above, the coating composition containing the silicone acrylic graft copolymer resin powder of the present invention forms a coating film that is excellent in transparency and gloss, as well as in sliding properties, water repellency, and stain resistance. [Industrial Applicability]

[0095] The coating composition of the present invention has gloss and sliding properties while maintaining excellent transparency, and can maintain high abrasion resistance without impairing the appearance of a laminate on which a film made of the coating composition is formed. The coating film also has high uniformity and good coatability. Furthermore, because it is water-based, it has significant advantages in terms of workability and the environment.

Claims

1. (A) an emulsion of a resin having film-forming ability selected from a urethane-based resin, an acrylic-based resin, and a vinyl chloride-based resin: 100 parts by mass in terms of solid content; and (B) 5 to 70 parts by mass of a silicone acrylic graft copolymer resin, which is a copolymer of a polyorganosiloxane represented by the following general formula (1) and at least one monomer selected from an acrylic acid ester monomer and a methacrylic acid ester monomer, wherein the mass ratio of the acrylic acid ester unit and the methacrylic acid ester unit to the polyorganosiloxane is 30:70 to 99:1 and the median diameter is 8 to 150 μm: A coating composition comprising 【Chemistry 1】 (In the formula, R 1 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 2 is a mercapto group, an alkyl group having 1 to 6 carbon atoms having an acryloxy group or a methacryloxy group, or a vinyl group; X is each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group; Y is X or —[O—Si(X) 2 ] d -X, and the above formula (1) has at least two silicon-bonded hydroxyl or alkoxy groups, Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, a is an integer from 0 to 1,000, b is a positive number from 100 to 10,000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1,000, provided that the bonding order of each siloxane unit in the above formula (1) is not limited to the above.

2. In the above general formula (1), R １ 2. The coating composition according to claim 1, wherein X and X are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

3. X and Y in the general formula (1) and the -[O-Si(X) ２ ] ｄ 3. The coating composition according to claim 1, wherein at least two of X in -X are hydroxyl groups or alkoxy groups.

4. 2. The coating composition according to claim 1, wherein (B) the silicone acrylic graft copolymer resin has a median diameter of 10 to 130 μm.

5. (B) the silicone acrylic graft copolymer resin is (b1) a polyorganosiloxane represented by the general formula (1), (b2) an acrylic acid ester monomer or a methacrylic acid ester monomer; Optionally, (b3) a functional group-containing monomer copolymerizable with the component (b2), 2. The coating composition according to claim 1, which is a copolymer of the following:

6. 2. The coating composition according to claim 1, wherein in a laminate having a substrate and a coating film made of the coating composition according to claim 1, the haze value of the coating film has an increase rate of 2000% or less compared to the haze value of the surface of the substrate not having the coating film.

7. A laminate comprising a substrate and a coating film made of the coating composition according to any one of claims 1 to 6, the coating film being formed on one or both sides of the substrate.

8. 8. The laminate according to claim 7, wherein the substrate is at least one selected from polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, polyester, cellulose, diethylene glycol bisallyl carbonate polymer, acrylonitrile-butadiene-styrene polymer, poly(meth)acrylic acid ester, polyurethane, and epoxy resin.

9. 8. The laminate according to claim 7, wherein the substrate is at least one selected from the group consisting of soda-lime glass, quartz glass, lead glass, borosilicate glass, and alkali-free glass.

10. 8. The laminate according to claim 7, wherein the substrate is at least one selected from woods of the families Maple, Birch, Lauraceae, Chestnut, Scrophulariaceae, Araucaria, Ulmaceae, Bignoniaceae, Rosaceae, Cupressaceae, Dipterocarpaceae, Myrtaceae, Fagaceae, Pinaceae, Fabaceae, and Oleaceae.

11. 8. The laminate according to claim 7, wherein the substrate is at least one fiber selected from cotton, hemp, linen, wool, silk, cashmere, asbestos, polyamide, polyester, viscose, cellulose, glass, and carbon.

12. The laminate according to any one of claims 7 to 11, wherein the thickness of the coating is 1 to 500 µm.

13. A powder made of a silicone acrylic graft copolymer resin having a median diameter (D50) of 8 to 150 μm, wherein the silicone acrylic graft copolymer is The powder is a copolymer of a polyorganosiloxane represented by the following general formula (1) and at least one monomer selected from an acrylic acid ester monomer and a methacrylic acid ester monomer, and the mass ratio of the acrylic acid ester unit and the methacrylic acid ester unit to the polyorganosiloxane is 30:70 to 99:

1. 【Chemistry 2】 (In the formula, R 1 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R 2 is a mercapto group, an alkyl group having 1 to 6 carbon atoms having an acryloxy group or a methacryloxy group, or a vinyl group; X is each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group; Y is X or —[O—Si(X) 2 ] d -X, and the above formula (1) has at least two silicon-bonded hydroxyl or alkoxy groups, Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, a is an integer from 0 to 1,000, b is a positive number from 100 to 10,000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1,000, provided that the bonding order of each siloxane unit in the above formula (1) is not limited to the above.

14. In the above general formula (1), R 1 and X are each independently a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

15. X and Y in the general formula (1) and the -[O-Si(X) ２ ] ｄ The powder according to claim 13 or 14, wherein at least two of X in -X are hydroxyl groups or alkoxy groups.

16. The silicone acrylic graft copolymer resin is (b1) a polyorganosiloxane represented by the general formula (1), (b2) an acrylic acid ester monomer or a methacrylic acid ester monomer; Optionally, (b3) a functional group-containing monomer copolymerizable with the component (b2), 14. The powder according to claim 13, which is a copolymer of

17. A powder for coating agents, comprising the silicone acrylic graft copolymer resin according to any one of claims 13 to 16.

18. A coating agent comprising the powder according to any one of claims 13 to 16.

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