Coating compositions, coated films and articles having the films

Abstract

The present invention provides a coating composition, a coated film, and a synthetic leather or a resin article having the coated film, the coating composition characterized by containing the following components: (A) a silicone acrylic copolymer resin which is a polymer containing (a1) an organopolysiloxane represented by a specific formula, and (a2) a mixture containing two or more acrylic monomers, the acrylic monomers of the (a2) component being adjusted so that the glass transition temperature (Tg) of the acrylic polymer obtained by polymerizing the (a2) component polymer is less than 60°C, as represented by Tg calculated from the glass transition temperatures (Tg) of the homopolymers of the respective acrylic monomers using the Fox equation, and (B) one or more organic solvents selected from a specific group. According to the present invention, when the coating composition is made into a coated film, excellent tactile sensation and gloss can be imparted, and even if the article having the coated film is stretched, whitening does not occur to impair the appearance.

Description

Technical Field

[0001] This invention relates to a coating composition containing an organosilicon acrylic copolymer resin, a coated film obtained by drying the composition, and an article having the film. More specifically, it relates to a coating composition, a coated film, and an article having the film, which, by coating the surface of a substrate such as leather or resin, can impart excellent tactile feel and gloss, and whose appearance is not impaired even when the article having the coated film is stretched. Background Technology

[0002] Previously, silicone resins were used to impart slip properties to substrates such as leather and resin. As a method to improve the abrasion resistance and slip properties of leather, it is known to incorporate silicone components such as silicone oil and silicone powder into the resin during leather manufacturing. For example, in Japanese Patent Application Publication No. 2007-138326 (Patent Document 1), which describes the manufacture of synthetic leather by incorporating acrylic-silicone copolymer particles into a polyurethane elastomer, improved abrasion resistance was successfully achieved. However, in this case, the manufacturing process becomes complex due to the need to incorporate the powder into the resin. Furthermore, to exhibit abrasion resistance, an increased amount of acrylic-silicone copolymer particles is required.

[0003] To address this problem, methods exist for coating the surface of leather, such as natural leather and synthetic leather, with resins. Japanese Patent Application Publication No. 2007-314919 (Patent Document 2) discloses a method that improves abrasion resistance by adding a crosslinking agent and a polyether-modified silicone surface finishing agent to an aqueous polyurethane resin and then coating it onto artificial leather. However, in this case, due to the increased hydrophilicity of the surface finishing agent, there are concerns about color transfer to the leather when dark beverages or liquids, such as coffee, adhere to it, and about color transfer from the fibers to the leather when wiping clothing, thus diminishing the stain-resistant properties of the leather surface.

[0004] Furthermore, as a method to improve the stain resistance of leather, methods such as coating the leather surface with resin are known. Japanese Patent Application Publication No. 2010-241963 (Patent Document 3) discloses a method of coating natural leather with a mixture of acrylic resin, acrylic silica resin, acrylic polysiloxane resin, and an organosilicon tactile agent. Japanese Patent Application Publication No. 2008-308785 (Patent Document 4) discloses the formation of an organosilicon resin film on the surface of synthetic leather made of polyurethane resin. However, for water-based coating agents, the water resistance and stain resistance performance are not sufficient.

[0005] International Publication No. 2019 / 244321 (Patent Document 5) discloses a method for coating synthetic leather with a treatment solution prepared by dissolving a base resin and an organosilicon acrylic resin in an organic solvent. While stain resistance is improved compared to existing methods, this method has the disadvantage of causing the coated leather to whiten when stretched, and there is room for improvement.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2007-138326

[0009] Patent Document 2: Japanese Patent Application Publication No. 2007-314919

[0010] Patent Document 3: Japanese Patent Application Publication No. 2010-241963

[0011] Patent Document 4: Japanese Patent Application Publication No. 2008-308785

[0012] Patent Document 5: International Publication No. 2019 / 244321 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] The present invention was made in view of the above-mentioned actual situation, and its object is to provide a coating composition having excellent tactile feel and gloss, a coating film that does not whiten even when stretched, and an article having the coating film.

[0015] Methods for solving problems

[0016] To achieve the above-mentioned objective, the inventors conducted in-depth research and discovered that in a coating composition containing an organosilicon acrylic copolymer resin, by using an acrylic monomer whose Tg is calculated according to a prescribed formula (hereinafter also referred to as "calculated Tg") of the homopolymer of each of the two or more acrylic monomers used for grafting with organopolysiloxane (organosilicon resin) is within a specified range, the polymer containing these acrylic monomers and organopolysiloxane, i.e., the specific organosilicon acrylic copolymer resin, is dissolved in an organic solvent. As a result, the coating composition not only has excellent touch and gloss, but also does not whiten even when the coating film made of the coating composition and the article having the coating film are stretched, without damaging the appearance. This invention is thus completed.

[0017] Therefore, the present invention provides a coating composition containing an organosilicon acrylic copolymer resin, a coating film obtained by drying the composition, and an article having the coating film.

[0018] 1. A coating composition, characterized in that it contains:

[0019] (A) An organosilicon acrylic copolymer resin, comprising 50-99 parts by mass of an organopolysiloxane represented by the following general formula (1) and 1-50 parts by mass of a mixture containing two or more acrylic monomers, wherein the acrylic monomers of component (a2) are modulated such that the glass transition temperature (Tg) of the acrylic polymer obtained by polymerizing component (a2) is expressed as Tg calculated using the Fox formula from the glass transition temperature (Tg) of the homopolymers of each acrylic monomer, and is less than 60°C.

[0020] (B) One or more organic solvents selected from amide compounds, ether compounds, ketone compounds, aromatic hydrocarbons and acetates.

[0021]

[0022] (where R is in the formula) 1 R is an unsubstituted or substituted monovalent hydrocarbon group with 1 to 20 carbon atoms, which may be the same or different. 2 It is an alkyl group having 1 to 6 carbon atoms substituted with a mercapto, acryloyloxy, or methacryloyloxy group. X is the same or different unsubstituted or substituted 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 is derived from -[O-Si(X)2]. d -X represents the same or different groups, where at least two of X and Y are hydroxyl groups. Z is an alkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, or a hydroxyl group. a is a positive number from 0 to 1000, b is a positive number from 100 to 10000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1000.

[0023] 2. The coating composition according to the above, wherein the organic solvent of component (B) is selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, methyl ethyl ketone, cyclopentanone, cyclohexanone, toluene, xylene, ethyl acetate and propylene glycol monoethyl ether acetate.

[0024] 3. The coating composition according to the above, wherein the organosilicon acrylic copolymer resin as component (A) is an emulsified graft polymer of a mixture of components (a1) and (a2).

[0025] 4. The coating composition according to the above, wherein the organopolysiloxane represented by formula (1) is a polymer of cyclic organosiloxane, α,ω-dihydroxysiloxane oligomer, α,ω-dialkoxysiloxane oligomer or alkoxysilane and the silane coupling agent represented by the following general formula (2).

[0026] R 3(4-e-f) R 4 f Si(OR 5 ) e (2)

[0027] (where R is in the formula) 3 R is an alkyl group having 1 to 6 carbon atoms substituted with mercapto, acryloyloxy, or methacryloyloxy. 4 It is an alkyl group having 1 to 4 carbon atoms, R 5 It is an alkyl group having 1 to 4 carbon atoms, where e is 2 or 3, f is 0 or 1, and e+f is 2 or 3.

[0028] 5. The coating composition according to the above, wherein the mixture of components (a2) contains at least two monomers, namely, a monomer whose glass transition temperature (Tg) of the homopolymer is 50°C or higher, and a monomer whose glass transition temperature (Tg) of the homopolymer is less than 50°C.

[0029] 6. The coating composition according to the above, wherein the organopolysiloxane of component (a1) has a weight-average molecular weight of 100,000 to 500,000.

[0030] 7. A coated film obtained by drying the coating composition described above.

[0031] 8. A synthetic leather or resin article having a coating as described above.

[0032] The effects of the invention

[0033] The coating composition of the present invention, by dissolving a specific organosilicon acrylic copolymer resin in an organic solvent, imparts excellent tactile feel and gloss when the coating composition is made into a coating film, and does not cause whitening or damage to the appearance even when the coated film is stretched. Detailed Implementation

[0034] The coating composition of the present invention contains (A) a specific organosilicon acrylic copolymer resin and (B) an organic solvent.

[0035] The following is a detailed description of each component.

[0036] The organosilicone acrylic copolymer resin, which is component (A), is a polymer of an organopolysiloxane represented by a specific formula and an acrylic monomer. Preferably, it is obtained by emulsifying and grafting a mixture of an organopolysiloxane represented by the following general formula (1) and an acrylic monomer containing two or more types of acrylic monomers.

[0037] Among them, (a1) organopolysiloxane is represented by the following general formula (1).

[0038]

[0039] (where R is in the formula) 1 R is an unsubstituted or substituted monovalent hydrocarbon group with 1 to 20 carbon atoms, which may be the same or different. 2 It is an alkyl group having 1 to 6 carbon atoms substituted with a mercapto, acryloyloxy, or methacryloyloxy group. X is the same or different unsubstituted or substituted 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 is derived from -[O-Si(X)2]. d -X represents the same or different groups, where at least two of X and Y are hydroxyl groups. Z is an alkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, or a hydroxyl group. a is a positive number from 0 to 1000, b is a positive number from 100 to 10000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1000.

[0040] Among them, R 1 This refers to monovalent hydrocarbon groups with 1 to 20 carbon atoms, whether identical or different, and specifically includes alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc.; cyclopentyl, cyclohexyl, cycloheptyl, etc.; vinyl, allyl, etc.; aryl, vinylphenyl, etc.; benzyl, phenylethyl, phenylpropyl, etc.; aralkyl, vinylbenzyl, vinylphenylpropyl, etc.; and groups in which some or all of the hydrogen atoms are replaced by halogen atoms such as fluorine, bromine, chlorine, acryloyloxy, methacryloyloxy, carboxyl, alkoxy, alkenyloxy, amino, alkyl or alkoxy or (meth)acryloyloxy substituted amino groups. As R 1 Preferably, it is methyl.

[0041] R 2 It is an alkyl group having 1 to 6 carbon atoms substituted with mercapto, acryloyloxy, or methacryloyloxy. Specifically, mercaptopropyl, acryloyloxypropyl, methacryloyloxypropyl, etc. are preferred.

[0042] X is the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group having 1 to 20 carbon atoms. As an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, it can be exemplified by the group in R. 1 The same group as the one exemplified herein, as an alkoxy group having 1 to 20 carbon atoms, specifically includes methoxy, ethoxy, propoxy, butoxy, hexoxy, heptoxy, octoxy, decoxy, tetradecoxy, etc. As X, hydroxyl, methyl, butyl, or phenyl are preferred.

[0043] Y is either X or composed of -[O-Si(X)2] d-X represents the same or different groups. d is a positive number from 1 to 1000, preferably a positive number from 1 to 200. Furthermore, in this invention, from the perspective of crosslinking, each molecule has at least two, preferably two to four, hydroxyl groups from X and Y, and preferably at both ends.

[0044] Z is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group, preferably a hydroxyl or methyl group.

[0045] If a becomes greater than 1000, the strength of the resulting cured product becomes insufficient; therefore, it is a positive number from 0 to 1000, preferably a positive number from 0 to 200. If b is less than 100, the cured product lacks flexibility; if it is greater than 10000, the tear strength of the resulting cured product decreases; therefore, it is a positive number from 100 to 10000, preferably a positive number from 1000 to 5000. c is a positive number from 1 to 10; if it exceeds 10, gelling particles are more easily generated during the reaction. It should be noted that the arrangement of the above repeating units can be block or random.

[0046] Such (a1) organopolysiloxanes are preferably used in emulsion form, and can be commercially available or synthesized. In the case of synthesis, well-known emulsion polymerization methods can be used. For example, cyclic organosiloxanes, α,ω-dihydroxysiloxane oligomers, α,ω-dialkoxysiloxane oligomers, alkoxysilanes, etc., which may have halogen atoms such as fluorine atoms, (meth)acryloyloxy groups, carboxyl groups, alkoxy groups, alkenoxy groups, alkenoxy groups, hydroxyl groups, amino groups, etc., are emulsified and dispersed in water with a silane coupling agent represented by the following general formula (2), and a catalyst such as an acid is added as needed to carry out a polymerization reaction, thereby enabling easy synthesis.

[0047] R 3 (4-e-f) R 4 f Si(OR 5 ) e (2)

[0048] (where R is in the formula) 3 R is an alkyl group having 1 to 6 carbon atoms substituted with mercapto, acryloyloxy, or methacryloyloxy. 4 It is an alkyl group having 1 to 4 carbon atoms, R 5 It is an alkyl group having 1 to 4 carbon atoms, where e is 2 or 3, f is 0 or 1, and e+f is 2 or 3.

[0049] Specifically, examples of the aforementioned cyclic organosiloxanes include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecylcyclohexasiloxane (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-methacryloyloxypropyl)tetramethylcyclotetrasiloxane. Siloxanes, including 1,3,5,7-tetra(3-acryloyloxypropyl)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, etc. Octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane are preferred.

[0050] Specifically, examples of silane coupling agents include acrylic silanes such as γ-(meth)acryloyloxypropyltrimethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, γ-(meth)acryloyloxypropyltripropoxysilane, γ-(meth)acryloyloxypropyltriisopropoxysilane, γ-(meth)acryloyloxypropyltributoxysilane, γ-(meth)acryloyloxypropylmethyldimethoxysilane, γ-(meth)acryloyloxypropylmethyldiethoxysilane, γ-(meth)acryloyloxypropylmethyldipropoxysilane, γ-(meth)acryloyloxypropylmethyldiisopropoxysilane, and γ-(meth)acryloyloxypropylmethyldibutoxysilane; and mercaptosilanes such as γ-mercaptopropylmethyldimethoxysilane and γ-mercaptopropyltrimethoxysilane. Alternatively, oligomers formed by their condensation polymerization can inhibit the formation of alcohols, which is sometimes more preferable. In this context, (meth)acryloyloxy represents acryloyloxy or methacryloyloxy.

[0051] With respect to these silane coupling agents, 0.01 to 20 parts by weight are preferred, and more preferably 0.01 to 5 parts by weight, relative to 100 parts by weight of cyclic organosiloxanes, α,ω-dihydroxysiloxane oligomers, α,ω-dialkoxysiloxane oligomers, or alkoxysilanes.

[0052] By copolymerizing with a silane coupling agent to obtain an organopolysiloxane having a siloxane unit of formula (1), the effect of grafting monomers of component (a2) is achieved.

[0053] In the above reaction, known polymerization catalysts can be used as catalysts for polymerization. Strong acids are preferred, examples of which include hydrochloric acid, sulfuric acid, dodecylbenzenesulfonic acid, citric acid, lactic acid, and ascorbic acid. Dodecylbenzenesulfonic acid, which has emulsifying ability, is particularly preferred.

[0054] The amount of acid catalyst used is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of cyclic organosiloxane, α,ω-dihydroxysiloxane oligomer, α,ω-dialkoxysiloxane oligomer or alkoxysilane, more preferably 0.2 to 2 parts by mass.

[0055] Furthermore, examples of anionic surfactants used for polymerization include sodium dodecyl sulfate, sodium lauryl ether sulfate, N-acyl amino acid salts, N-acyl taurate, aliphatic soaps, and alkyl phosphates. Among these, anionic surfactants that are readily soluble in water and do not possess polyoxyethylene chains are preferred. N-acyl amino acid salts, N-acyl taurate, aliphatic soaps, and alkyl phosphates are more preferred, and sodium lauroyl methyl taurate, sodium myristoyl methyl taurate, and sodium dodecyl sulfate are particularly preferred.

[0056] Regarding the amount of anionic surfactant used, it is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of cyclic organosiloxane, α,ω-dihydroxysiloxane oligomer, α,ω-dialkoxysiloxane oligomer or alkoxysilane.

[0057] The polymerization temperature is preferably 50–75°C, and the polymerization time is preferably 10 hours or more, more preferably 15 hours or more. Furthermore, it is particularly preferred to cure the polymer solution at 5–30°C for 10 hours or more after polymerization. Additionally, the pH of the resulting polymerization solution is preferably 6–8.

[0058] The obtained (a1) organopolysiloxane preferably has a weight-average molecular weight of 100,000 to 500,000, more preferably 150,000 to 450,000. By achieving this weight-average molecular weight, a coating agent (coating composition) that imparts the excellent sliding properties characteristic of organosilicon is obtained. It should be noted that in this invention, the weight-average molecular weight (Mw) can be calculated from the specific viscosity ηsp (25°C) of a toluene solution of organopolysiloxane at a concentration of 1 g / 100 ml.

[0059] ηsp=(η / η0)-1

[0060] (η0: viscosity of toluene; η: viscosity of the solution)

[0061] ηsp=[η]+0.3[η] 2

[0062] [η] = 2.15 × 10 -4 M 0.65

[0063] Specifically, 20g of emulsion was mixed with 20g of IPA (isopropanol). After the emulsion was broken down, the IPA was discarded, and the remaining rubbery organopolysiloxane was dried at 105°C for 3 hours. This resulted in a toluene solution of organopolysiloxane with a concentration of 1g / 100ml, which was measured using an Ubbelohde viscometer at 25°C. By substituting the viscosity into the above formula, the molecular weight could be determined (References: Nakamuta, Nichika, 77 858

[1956] , Doklady Akad.Nauk.USSR89 65

[1953] ).

[0064] In the above reaction, for example, taking the case where octamethyltetrasiloxane is used as a cyclic organosiloxane and γ-methacryloyloxypropylmethyldimethoxysilane is used as a silane coupling agent, as described below.

[0065]

[0066] The (a2) component of the present invention is a mixture containing two or more acrylic monomers. Examples of acrylic monomers (hereinafter sometimes referred to as "acrylic components") include acrylic acid, methacrylic acid, acrylates, and methacrylates. Acrylates and methacrylates are preferred. Specifically, examples include methyl methacrylate, ethyl methacrylate, butyl methacrylate, allyl methacrylate, tert-butyl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, stearyl methacrylate, dodecyl methacrylate, urea methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, tert-butyl acrylate, glycidyl acrylate, isodecanyl acrylate, hexyl acrylate, lauryl acrylate, dodecyl acrylate, stearyl acrylate, hydroxypropyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, ethyl diethylene glycol acrylate, and dihydrocyclopentadiene acrylate. Two or more of these monomers can be used. In particular, it is preferred to select 3 or more but no more than 10 acrylic monomers.

[0067] For component (a2) above, the type and amount of acrylic monomers in component (a2) are appropriately selected such that the glass transition temperature (Tg) of the acrylic polymer obtained by polymerizing the acrylic components of component (a2) (also called "polymer of acrylic components") is less than 60°C, calculated using the glass transition temperature (Tg) of the homopolymers of each acrylic monomer using the Fox formula. Specifically, the (Tg) of this acrylic polymer calculated using the Fox formula is the glass transition temperature obtained using the following formula.

[0068] That is, when the glass transition temperature (K) of the acrylic polymer is set as Tg, and the glass transition temperature (K) of the homopolymer of each acrylic monomer used is set as Tg1, Tg2, ..., Tgn, and the content (mass%) of each acrylic monomer is set as P1, P2, ..., Pn, it is represented by the following formula (I): (P1+P2+...Pn) / Tg=(P1 / Tg1)+(P2 / Tg2)+...+(Pn / Tgn)(I)

[0069] It should be noted that P1+P2+····Pn=100 (mass%), and the glass transition temperature (K) of the homopolymer of each of the above acrylic monomers can be determined based on JIS K7121.

[0070] In this invention, the glass transition temperature (hereinafter sometimes simply referred to as "calculated Tg") calculated according to the above formula (I) is less than 60°C, more preferably less than 55°C, and even more preferably less than 50°C. On the other hand, as a lower limit, it is preferably 30°C or more, more preferably 40°C or more. If the above-mentioned calculated Tg exceeds 60°C, the coated film will whiten when stretched, and the effects of this invention will no longer be obtained.

[0071] For the mixture of components (a2) above, it is preferable to contain two or more monomers with a glass transition temperature (Tg) of 50°C or higher and monomers with a glass transition temperature (Tg) of less than 50°C. This is because by using monomers with a Tg of 50°C or higher for the homopolymer, the flowability of the powder during drying and powdering is ensured; and by using monomers with a Tg of less than 50°C for the homopolymer, the polymer is given flexibility. Even after dissolving in a solvent and coating onto a substrate, the coated film made of this coating composition and the article having the film do not whiten, and there is no tendency to damage the appearance.

[0072] Examples of acrylic monomers with a Tg of 50°C or higher as homopolymers include methyl methacrylate (105°C), acrylic acid (106°C), acrylonitrile (105°C), methacrylic acid (185°C), allyl methacrylate (52°C), 2-hydroxyethyl methacrylate (55°C), isobornyl acrylate (97°C), and ethyl methacrylate (65°C). Preferably, the acrylic monomer with a Tg of 50°C or higher as a homopolymer contains at least methyl methacrylate.

[0073] On the other hand, monomers with a Tg of less than 50°C as homopolymers include ethyl acrylate (-22°C), butyl acrylate (-52°C), 2-ethylhexyl acrylate (-70°C), isobutyl acrylate (-40°C), methyl acrylate (8°C), n-butyl methacrylate (20°C), isobutyl methacrylate (48°C), lauryl acrylate (15°C), etc.

[0074] Regarding the mixing ratio of monomers with a Tg of 50°C or higher to monomers with a Tg of less than 50°C in the homopolymer, there are no particular limitations as long as the design is based on a Tg of less than 60°C. Specifically, the monomers with a Tg of 50°C or higher in the homopolymer are preferably 50 to 99 parts by mass, and the monomers with a Tg of less than 50°C are preferably 1 to 50 parts by mass. More preferably, the monomers with a Tg of 50°C or higher in the homopolymer are 50 to 80 parts by mass, and the monomers with a Tg of less than 50°C are 20 to 50 parts by mass.

[0075] The organopolysiloxane of formula (1) obtained as described above preferably has 2 to 10 crosslinking points per mole of polymer, more preferably 2 to 6 points, which can induce graft polymerization with component (a2).

[0076] Regarding the organosilicone acrylic graft copolymer resin as component (A), firstly, the acrylic monomer (a2) is graft polymerized with the organopolysiloxane (a1) obtained as described above. In this case, it is preferable to perform emulsion graft polymerization of component (a2) and component (a1).

[0077] In this case, the mass ratio of the organopolysiloxane of formula (1) to the acrylic monomer during graft polymerization is 50:50 to 99:1, preferably 60:40 to 99:1. If the organosilicon content is less than 50 by mass ratio, sufficient abrasion resistance may not be observed.

[0078] Furthermore, relative to 100 parts by mass of component (a1) above, it is preferable to use 1 to 100 parts by mass of component (a2) above, more preferably 10 to 100 parts by mass, and even more preferably 20 to 100 parts by mass.

[0079] Examples of free radical initiators used for graft polymerization include potassium persulfate, ammonium persulfate, persulfates, hydrogen persulfate, tert-butyl hydroperoxide, and hydrogen peroxide. Redox systems combining reducing agents such as acidic sodium sulfite, sodium silicate, L-ascorbic acid, tartaric acid, sugars, and amines can also be used as needed. The amount of free radical initiator used is preferably 0.1 to 5% by mass of the total amount of component (a2), more preferably 0.5 to 3% by mass.

[0080] Graft polymerization can be fully carried out using the surfactant already contained in the emulsion during the preparation of organopolysiloxanes. To improve stability, anionic surfactants such as sodium dodecyl sulfate, sodium lauryl ether sulfate, N-acyl amino acid salts, N-acyl taurate, aliphatic soaps, and alkyl phosphates can be added. Alternatively, nonionic emulsifiers such as polyoxyethylene lauryl ether and polyoxyethylene tridecyl ether can also be added. The preferred amount of surfactant used is 0.1–5% by mass of component (a2).

[0081] Furthermore, chain transfer agents can be added to adjust the molecular weight and grafting rate of the grafted polymer.

[0082] The preferred graft polymerization temperature is 25–55°C, more preferably 25–40°C. The preferred polymerization time is 2–8 hours, more preferably 3–6 hours.

[0083] The resulting organosilicon acrylic copolymer resin is a polymer in which components (a2) and (a1) are randomly grafted.

[0084] Furthermore, the organosilicon-acrylic copolymer resin obtained above is preferably 30-50% by mass, based on the solids content of the emulsion. Additionally, the viscosity of the emulsion (at 25°C) is preferably 10-5000 mPa·s, more preferably 50-1000 mPa·s. The viscosity can be measured using a rotational viscometer. The average particle size of the emulsion is preferably 1 μm or less, preferably 0.1 μm (100 nm) to 0.3 μm (300 nm). The pH is preferably 6-8. It should be noted that the average particle size can be measured using a laser diffraction / scattering particle size distribution measuring device.

[0085] The obtained organosilicon-acrylic graft copolymer resin is in emulsion form. Therefore, after concentrating the dispersion by methods such as heating dehydration, filtration, centrifugation, and decantation, it is washed with water as needed. Then, moisture is removed through methods such as heating and drying under normal or reduced pressure, spray drying by spraying the dispersion in an airflow, or heating and drying using a flowing heat medium, resulting in temporary drying and powdering. The preferred drying temperature is 50–200°C. If some agglomeration occurs in the obtained powder, it can be appropriately crushed using a jet mill, ball mill, hammer mill, or other pulverizer.

[0086] To remove residual cyclic organosiloxanes and surfactants from the obtained organosilicon-acrylic graft copolymer resin, washing is sometimes performed. For this purpose, alcohol-based or hydrocarbon-based organic solvents are preferred, including lower alcohols with 1 to 4 carbon atoms and aliphatic hydrocarbons with 5 to 20 carbon atoms; more specifically, methanol, ethanol, isopropanol, hexane, and isododecane are preferred. As for the washing method, for example, 100 parts by weight of the powder are taken in a beaker, and more than five times its weight of the aforementioned solvent is added. After stirring for several hours, the mixture is filtered. Then, washing with the same solvent, or with water using an alcohol-based solvent that is soluble in water, is more effective. In this case, the washing is usually carried out at room temperature (25°C), and sometimes heating is used.

[0087] In the case of cleaning, the powder is then re-dried to form a powder. For filtered powder, it can be dried for several hours using a dryer at a temperature above 40°C and below 200°C, or a flow dryer can be used.

[0088] The resulting organosilicon-acrylic copolymer resin preferably has an average particle size of less than 100 μm, and particularly preferably 10–50 μm. It should be noted that the above-mentioned average particle size refers to the particle size measured using a dynamic light scattering method.

[0089] Examples of organic solvents used as (B) include amide compounds such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; ether compounds such as 1,4-dioxane, 1,3-dioxolane, and tetrahydrofuran; ketone compounds such as methyl ethyl ketone, cyclopentanone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; and acetate esters such as ethyl acetate and propylene glycol monoethyl ether acetate. Organic solvents can be used alone or in mixtures.

[0090] The amount of the specific organosilicon acrylic copolymer resin (A) is not particularly limited as long as it is soluble in the organic solvent (B). It is preferred to be 1 to 60 parts by mass, and more preferably 10 to 50 parts by mass, relative to 100 parts by mass of the organic solvent (B).

[0091] The coating composition of the present invention is obtained by mixing and dissolving (A) an organosilicon acrylic copolymer resin and (B) an organic solvent using known mixing preparation methods such as a propeller mixer, homogenizer, ball mill, or bead mill.

[0092] In addition, in the coating composition of the present invention, within a range that does not affect performance, other than component (A), such as resins, pigments, matting agents, antioxidants, ultraviolet absorbers, antifreeze agents, pH adjusters, preservatives, defoamers, antibacterial agents, antifungal agents, light stabilizers, antistatic agents, plasticizers, flame retardants, thickeners, surfactants, film-forming aids, organic solvents, and other resins may be added.

[0093] If the coating composition of the present invention obtained in this way is coated or impregnated on one or both sides of a substrate such as synthetic leather or resin and dried (room temperature to 150°C), it is characterized in that it can impart excellent tactile feel and gloss, and its appearance is not impaired even when the coated article is stretched.

[0094] The synthetic leather uses products formed from vinyl chloride-based resins and polyurethanes on a substrate. As the resin substrate, poly(meth)acrylates such as polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, polyester, cellulose, allyl dicarbonate polymers, acrylonitrile-butadiene-styrene polymers, polyurethane, and epoxy resins are used. As a drying method, methods such as leaving it at room temperature for 1 to 10 days are listed. From the viewpoint of rapid curing, methods of heating at a temperature of 20 to 150°C for 1 second to 10 hours are preferred. Furthermore, if the resin substrate is made of a material that is easily deformed or discolored by heating, drying at a lower temperature of 20 to 100°C is preferred.

[0095] There are no particular limitations on the method of applying the coating composition of the present invention to the substrate. For example, coating methods using various coating machines such as photogravure coating machines, bar coating machines, doctor blade coating machines, roller coating machines, air knife coating machines, screen coating machines, and curtain coating machines, as well as spraying, dipping, and brush coating, can be listed.

[0096] There is no particular limitation on the coating amount of the coating composition of the present invention on the substrate. Generally, considering factors such as stain resistance and workability, it is preferred to use 1 to 300 g / m² when calculated based on solid content. 2 More preferably, 5-100 g / m 2 The film can be formed in the range of 1 to 500 μm, preferably 5 to 100 μm, and can be naturally dried or heated to 100 to 200°C to form a film.

[0097] The coating composition of the present invention is characterized in that, when used on synthetic leather or resin articles, it can impart excellent tactile feel and gloss, and its appearance is not impaired even when the article with the coated film is stretched.

[0098] There are no particular limitations on the substrate on which the coating composition of the present invention is applied. By producing synthetic leather or resin articles with a known film thickness range of 0.1 to 10 mm, the property of not damaging the appearance even when stretched can be effectively achieved.

[0099] Example

[0100] The following examples, embodiments, and comparative examples illustrate the invention in detail, but the invention is not limited to the following embodiments. It should be noted that in the examples below, parts and % represent parts by mass and percentage by mass, respectively.

[0101] [Manufacturing Example 1]

[0102] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0103] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice to obtain a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution to obtain an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, had a non-volatile content of 45.4% and the organopolysiloxane in the emulsion was a non-flowing, soft gel-like product. The structure of the organopolysiloxane obtained through the above polymerization reaction is as follows: 1 H-NMR (frequency 600MHz, room temperature, cumulative count 128 times) and 29 Si-NMR (frequency 600 MHz, room temperature, cumulative strikes 5000) (apparatus: JNM-ECA600, solvent: CDCl3) was used for confirmation. It should be noted that the weight-average molecular weight (Mw) of the organopolysiloxane (a1) was determined as described above and is shown in Table 1.

[0104] Manufacturing Example 1 (A) of the manufacture of organosilicon acrylic graft copolymer resin

[0105] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), butyl acrylate (BA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / BA / AMA = 75.8 / 24 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic modified organopolysiloxane) containing approximately 45% acrylic silicone resin, comprising an acrylic graft copolymer resin. The average particle size of this emulsion was 280 nm. It should be noted that the Tg of the acrylic components was calculated using the above formula with the above mass ratios of methyl methacrylate (homopolymer Tg: 105℃), butyl acrylate (homopolymer Tg: -52℃), and allyl methacrylate (homopolymer Tg: 52℃), and the result was 50℃. It should be noted that the above Tg values ​​are based on measurements according to JIS K7121. By spray drying, an organosilicon acrylic copolymer resin powder can be obtained (Manufacturing Example 1). It should be noted that the weight-average molecular weight (Mw) of (a1) is shown in Table 1, and this Mw was determined by the method described above.

[0106] [Manufacturing Example 2]

[0107] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0108] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0109] Manufacturing Example 2 (A) Manufacturing of Organosilicon Acrylic Graft Copolymer Resin

[0110] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), butyl acrylate (BA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / BA / AMA = 70.5 / 29.3 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic modified organopolysiloxane) containing approximately 45% silicone acrylic graft copolymer resin. The average particle size of this emulsion was 270 nm. It should be noted that, for the calculation of Tg of the above acrylic components, methyl methacrylate (homopolymer Tg: 105°C), butyl acrylate (homopolymer Tg: -52°C), and allyl methacrylate (homopolymer Tg: 52°C) were calculated using the above formula at the above mass ratio, and the result was 40°C. By spray drying, silicone acrylic copolymer resin powder was obtained (Manufacturing Example 2).

[0111] [Manufacturing Example 3]

[0112] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0113] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 10°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0114] Manufacturing Example 3 (A) Manufacturing of Organosilicon Acrylic Graft Copolymer Resin

[0115] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), butyl acrylate (BA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / BA / AMA = 75.8 / 24 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic-modified organopolysiloxane) containing approximately 45% silicone acrylic graft copolymer resin. The average particle size of this emulsion was 280 nm. It should be noted that, for the calculation of Tg of the above acrylic components, methyl methacrylate (homopolymer Tg: 105°C), butyl acrylate (homopolymer Tg: -52°C), and allyl methacrylate (homopolymer Tg: 52°C) were calculated using the above formula at the above mass ratio, and the result was 50°C. By spray drying, silicone acrylic copolymer resin powder was obtained (Manufacturing Example 3).

[0116] [Manufacturing Example 4]

[0117] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0118] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0119] Manufacturing Example 4(A) Manufacturing of Organosilicon Acrylic Graft Copolymer Resin

[0120] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), 2-ethylhexyl acrylate (AEH), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / AEH / AMA = 79.8 / 20 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic modified organopolysiloxane) containing approximately 45% acrylic silicone resin, comprising an acrylic graft copolymer resin. The average particle size of this emulsion was 270 nm. It should be noted that, for the calculation of the Tg of the above acrylic components, methyl methacrylate (homopolymer Tg: 105℃), 2-ethylhexyl acrylate (homopolymer Tg: -70℃), and allyl methacrylate (homopolymer Tg: 52℃) were calculated using the above formula at the above mass ratio, and the result was 50℃. By spray drying the powder, organosilicon acrylic copolymer resin powder can be obtained (manufacturing example 4).

[0121] [Manufacturing Example 5]

[0122] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0123] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0124] Manufacturing Example 5 (A) of the manufacture of organosilicon acrylic graft copolymer resin

[0125] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), ethyl acrylate (EA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / EA / AMA = 65.8 / 34 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic-modified organopolysiloxane) containing approximately 45% acrylic silicone resin graft copolymer resin. The average particle size of this emulsion was 270 nm. It should be noted that, for the calculation of Tg of the acrylic components above, methyl methacrylate (homopolymer Tg: 105°C), ethyl acrylate (homopolymer Tg: -22°C), and allyl methacrylate (homopolymer Tg: 52°C) were calculated using the above formula at the above mass ratio, and the result was 50°C. By spray drying, silicone acrylic copolymer resin powder was obtained (Manufacturing Example 5).

[0126] [Comparative Manufacturing Example 1]

[0127] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0128] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0129] Manufacturing of (A) Organosilicon Acrylic Grafted Copolymer Resin in Comparative Manufacturing Example 1

[0130] In the silicone emulsion composition obtained above, methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (2-HEMA) were added dropwise over 3 to 5 hours at a ratio of MMA / 2-HEMA = 98 / 2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic-modified organopolysiloxane) containing approximately 45% acrylic silicone resin graft copolymer resin. The average particle size of this emulsion was 290 nm. It should be noted that, for the calculation of Tg of the acrylic component above, methyl methacrylate (homopolymer Tg: 105°C) and 2-hydroxyethyl methacrylate (homopolymer Tg: 55°C) were calculated using the above formula at the above mass ratio, and the result was 104°C. By spray drying, silicone acrylic copolymer resin powder was obtained (Comparative Manufacturing Example 1).

[0131] [Comparative Manufacturing Example 2]

[0132] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0133] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0134] Comparative manufacturing example 2 (A) Manufacturing of organosilicon acrylic graft copolymer resin

[0135] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), butyl acrylate (BA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / BA / AMA = 89.8 / 10 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic-modified organopolysiloxane) containing approximately 45% of an acrylic silicone resin graft copolymer resin. The average particle size of this emulsion was 280 nm. It should be noted that, for the calculation of Tg of the above acrylic components, methyl methacrylate (homopolymer Tg: 105°C), butyl acrylate (homopolymer Tg: -52°C), and allyl methacrylate (homopolymer Tg: 52°C) were calculated using the above formula at the above mass ratio, and the result was 80°C. By spray drying, an acrylic silicone copolymer resin powder was obtained (Comparative Manufacturing Example 2).

[0136] [Comparative Manufacturing Example 3]

[0137] (a1) Preparation of emulsion compositions containing organopolysiloxanes

[0138] The products obtained by dissolving 828g of octamethylcyclotetrasiloxane, 0.7g of 3-methacryloyloxypropyldimethoxysilane, and 8.3g of sodium dodecyl sulfate in 75g of pure water, and the product obtained by dissolving 8.3g of dodecylbenzenesulfonic acid in 75g of pure water, were placed in 2L polyethylene beakers. After homogeneous emulsification using a homogeneous mixer, 629g of pure water was slowly added for dilution at a pressure of 300kgf / cm². 2 The emulsion was passed through a high-pressure homogenizer twice, yielding a homogeneous white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser, and polymerized at 55°C for 24 hours. After aging at 15°C for 24 hours, it was neutralized to pH 6-8 with 27g of a 10% sodium carbonate aqueous solution, yielding an organosilicon emulsion composition. This emulsion, after drying at 105°C for 3 hours, contained 45.4% non-volatile components and was a non-flowing, soft gel-like product containing organopolysiloxanes.

[0139] Comparative manufacturing example 3 (A) Manufacturing of organosilicon acrylic graft copolymer resin

[0140] In the silicone emulsion composition obtained above, methyl methacrylate (MMA), butyl acrylate (BA), and allyl methacrylate (AMA) were added dropwise over 3-5 hours at a ratio of MMA / BA / AMA = 80.8 / 19 / 0.2 (%), while peroxide and reducing agent were added at room temperature to carry out a redox reaction and perform acrylic graft copolymerization, resulting in an acrylic silicone resin emulsion (acrylic-modified organopolysiloxane) containing approximately 45% silicone acrylic graft copolymer resin. The average particle size of this emulsion was 280 nm. It should be noted that, for the calculation of Tg of the above acrylic components, methyl methacrylate (homopolymer Tg: 105°C), butyl acrylate (homopolymer Tg: -52°C), and allyl methacrylate (homopolymer Tg: 52°C) were calculated using the above formula at the above mass ratio, and the result was 60°C. By spray drying, silicone acrylic copolymer resin powder was obtained (Comparative Manufacturing Example 3).

[0141] < Methods for determining softening temperature and flow start temperature >

[0142] For the silicone-acrylic copolymer resins of Manufacturing Examples 1-5 and Comparative Manufacturing Examples 1-3, the measurements were performed using a capillary rheometer (CFT-500D, manufactured by Shimadzu Corporation) under a load of 5 kgf and by the heating method.

[0143] The softening temperature is preferably 40–80°C, more preferably 50–70°C. A lower softening temperature results in a softer film, but thermal fusion may occur when the film is dried; therefore, the above-mentioned range is preferred.

[0144] In addition, the preferred flow start temperature is 100–160°C.

[0145] Table 1

[0146]

[0147] The Tg values ​​for forming homopolymers of the acrylic monomers listed in Table 1 are as follows.

[0148] MMA: Methyl methacrylate; Tg: 105℃

[0149] BA: Butyl acrylate Tg: -52℃

[0150] AEH: 2-Ethylhexyl acrylate Tg: -70℃

[0151] EA: Ethyl acrylate Tg: -22℃

[0152] AMA: Allyl methacrylate; Tg: 52℃

[0153] 2-HEMA: 2-Hydroxyethyl methacrylate; Tg: 55℃

[0154] [Example 1]

[0155] A mixed solvent was prepared by mixing 30 parts toluene, 30 parts methyl ethyl ketone, and 20 parts N,N-dimethylformamide. 20 parts of the organosilicon-acrylic copolymer resin obtained in Manufacturing Example 1 were dissolved to prepare a coating composition. The coating composition was applied to polyurethane synthetic leather (1 mm thick) using a doctor blade, and dried to approximately 15 μm. The mixture was then dried at 120°C for 1 minute to form a coating film on the polyurethane synthetic leather.

[0156] The obtained coating was evaluated using the method described below. The results are shown in Table 2.

[0157] <Methods for measuring gloss>

[0158] Visual evaluation was conducted on the polyurethane synthetic leather that had formed a coating.

[0159] ○: You can see a high-end luster.

[0160] △: A slight sheen can be seen.

[0161] ×: Almost no gloss effect was observed.

[0162] <Methods for measuring touch>

[0163] For polyurethane synthetic leather with a coating, a tactile sensory evaluation was performed using fingers.

[0164] ○: It has a unique and pleasant slippery feel.

[0165] △: Slightly slippery.

[0166] ×: The fingers feel resistance, but there is no slippery feeling.

[0167] <Method for determining stretch whitening>

[0168] Before washing: The black polyurethane synthetic leather (1mm thick) was stretched vigorously to form a coating, and the color change of the area under tension was visually evaluated.

[0169] After washing: Rub the black polyurethane synthetic leather with the coating formed under running water for 1 minute, wipe off the moisture, and dry at room temperature for 24 hours. Then stretch it vigorously and visually evaluate the color change of the area under tension.

[0170] ○: No whitening was detected.

[0171] △: Albinism was found in some areas.

[0172] ×: Overall, whitening was observed.

[0173] <Methods for determining the coefficient of friction>

[0174] A 200g metal indenter was used to make vertical contact with a coated polyurethane synthetic leather using HEIDON TYPE-38 (manufactured by Shin-Dong Science Co., Ltd.). The frictional force was measured when the leather moved at a speed of 3cm / min, and the coefficient of friction was calculated from the frictional force.

[0175] It should be noted that, with regard to the preferred range of static and dynamic friction coefficients in polyurethane synthetic leather, the static friction coefficient is 0.01 to 0.40, and the dynamic friction coefficient is 0.01 to 0.30.

[0176] [Examples 2-5, Comparative Examples 1-3]

[0177] The silicone-acrylic copolymer resin and organic solvent were formulated in the proportions shown in Table 2 and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0178] Table 2

[0179]

[0180] As shown in Table 2, the coating compositions of the present invention (Examples 1-5) are coating compositions with excellent tactile feel and gloss, and have a coating film that does not whiten even when stretched, and are therefore most suitable for coating synthetic leather or resin articles.

Claims

1. A coating composition, characterized in that, contain: (A) An organosilicon acrylic copolymer resin, which is an emulsified graft polymer comprising a mixture of (a1) and (a2): (a1) 50 to 99 parts by mass of an organopolysiloxane represented by the following general formula (1), and (a2) 1 to 50 parts by mass of a mixture of two or more acrylic monomers, comprising 50 to 99 parts by mass of an acrylic monomer having a glass transition temperature (Tg) of 50°C or higher and 1 to 50 parts by mass of an acrylic monomer having a glass transition temperature (Tg) of less than 50°C, wherein the acrylic monomers of component (a2) are prepared such that the glass transition temperature (Tg) of the acrylic polymer obtained by polymerizing component (a2) is expressed as Tg calculated by the Fox formula from the glass transition temperature (Tg) of the homopolymer of each acrylic monomer, and is less than 60°C. (B) One or more organic solvents selected from amide compounds, ether compounds, ketone compounds, aromatic hydrocarbons, and acetate esters. In the formula, R 1 R is an unsubstituted or substituted monovalent hydrocarbon group with 1 to 20 carbon atoms, which may be the same or different. 2 It is an alkyl group having 1 to 6 carbon atoms substituted with mercapto, acryloyloxy, or methacryloyloxy; X is the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, or hydroxyl group; Y is X or is derived from -[O-Si(X)2]. d -X represents the same or different groups, at least two of X and Y are hydroxyl groups, Z is an alkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, or a hydroxyl group, a is a positive number from 0 to 1000, b is a positive number from 100 to 10000, c is a positive number from 1 to 10, and d is a positive number from 1 to 1000.

2. The coating composition according to claim 1, wherein, (B) The organic solvent of the component is selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, methyl ethyl ketone, cyclopentanone, cyclohexanone, toluene, xylene, ethyl acetate and propylene glycol monoethyl ether acetate.

3. The coating composition according to claim 1 or 2, wherein, The organopolysiloxane represented by formula (1) is a polymer of cyclic organosiloxane, α,ω-dihydroxysiloxane oligomer, α,ω-dialkoxysiloxane oligomer, alkoxysilane and the silane coupling agent represented by the following general formula (2). R 3 (4-e-f) R 4 f Si(OR 5 ) e (2) In the formula, R 3 R is an alkyl group having 1 to 6 carbon atoms substituted with mercapto, acryloyloxy, or methacryloyloxy. 4 It is an alkyl group having 1 to 4 carbon atoms, R 5 It is an alkyl group with 1 to 4 carbon atoms, where e is 2 or 3, f is 0 or 1, and e+f is 2 or 3.

4. The coating composition according to claim 1 or 2, wherein, The weight-average molecular weight of the organopolysiloxane in component (a1) is 100,000 to 500,000.

5. A coated film obtained by drying the coating composition according to any one of claims 1 to 4.

6. A synthetic leather or resin article having the coating as described in claim 5.

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