Paint composition, coated article, and method for forming a cured film

Abstract

To provide a coating composition which can be easily produced and gives a cured film having excellent hardness, chemical resistance, antifouling properties, and weather resistance.SOLUTION: The coating composition contains: (A) 100 pts.mass of one or more polyols selected from acrylic polyols, polyester polyols and polyether polyols; (B) 0.5-20 pts.mass of a silane coupling agent having an isocyanurate skeleton; and (C) 5-100 pts.mass of an organopolysiloxane represented by the following formula (I) (where each R1 independently represents a substituted or unsubstituted C1-12 monovalent hydrocarbon group; R2 represents a hydrogen atom or a C1-6 alkyl group; a, b, c and d are numbers satisfying 0≤a≤1, 0≤b≤1, 0≤c≤0.5, 0≤d<1, a+b+c+d=1 and 0.5<(a+b)≤1; and e is a number satisfying 0<e≤4).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a paint composition, a coated article, and a method for forming a cured film, and more specifically, to a paint composition comprising an organic resin and an organopolysiloxane, a coated article having a cured film made of the paint composition, and a method for forming a cured film made of the paint composition. [Background technology]

[0002] Paints primarily composed of organopolysiloxane resins are widely used in the fields of architecture and civil engineering due to their excellent film hardness, chemical resistance, and weather resistance. While this organopolysiloxane-based coating has the advantages mentioned above, it also has the disadvantages of a slow curing speed and poor crack resistance in the resulting coating film.

[0003] To overcome these drawbacks, a method has been known in which a composition obtained by mixing organopolysiloxane with an organic resin such as an alkyd resin, polyester resin, acrylic resin, or epoxy resin is used as a paint. As such a composition, for example, Patent Document 1 proposes a paint composition containing a silyl group-containing vinyl polymer, a silanol group-containing organopolysiloxane, and an alkoxy group-containing organopolysiloxane. However, while this composition improves curability and crack resistance, it has the problem of reducing the hardness, chemical resistance, heat resistance, and weather resistance of organopolysiloxane-based resin coatings, which are characteristic of such coatings.

[0004] Also, Patent Document 2~ 4 While a method for compounding organic resins with organosilanes or organopolysiloxanes has been disclosed, this method has limitations in terms of versatility because it requires synthesis equipment for compounding the resins. Therefore, there is a need for a simple method to bring out the properties of both organopolysiloxanes and organic resins. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Laid-Open No. 3-197548 [Patent Document 2] Japanese Patent Laid-Open No. 11-116683 [Patent Document 3] Japanese Patent Laid-Open No. 5-345877 [Patent Document 4] Japanese Patent No. 5384939 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a coating composition containing an organic resin and an organopolysiloxane, which can be easily manufactured and gives a cured film having excellent hardness, chemical resistance, antifouling property, and weather resistance. [Means for Solving the Problems]

[0007] As a result of intensive studies to achieve the above object, the present inventor has found that a coating composition obtained by mixing a polyol, a silane coupling agent having an isocyanurate skeleton, and a predetermined organopolysiloxane in a predetermined ratio can be cured by heating, and a coating film obtained from the composition satisfies the above properties such as hardness, and has completed the present invention.

[0008] That is, the present invention provides 1. (A) One or more polyols selected from the group consisting of acrylic polyol, polyester polyol, and polyether polyol: 100 parts by mass, (B) A silane coupling agent having an isocyanurate skeleton: 0.5 to 20 parts by mass, and (C) An organopolysiloxane represented by the following formula (I): 5 to 100 parts by mass [Chemical Formula] (In the formula, R1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, which may be substituted or unsubstituted, and R 2 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a, b, c, d are numbers satisfying 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ c ≦ 0.5, 0 ≦ d < 1, a + b + c + d = 1, and 0.5 < (a + b) ≦ 1, and e is a number satisfying 0 < e ≦ 4.) A paint composition containing 2. The paint composition according to claim 1, wherein the component (A) is an acrylic polyol, a polyester polyol, or both of them. 3. The paint composition according to claim 1, wherein the component (B) is a compound represented by the following formula (II). [Chemical formula] (In the formula, R 3 each independently represents an alkylene group having 1 to 20 carbon atoms, R 4 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, which may be substituted or unsubstituted, and R 5 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and f is each independently 0, 1, or 2.) 4. In the formula (I), the paint composition according to claim 1, wherein R 1 each independently is an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. 5. In the formula (I), the paint composition according to claim 4, wherein R 1 each independently is a methyl group, an ethyl group, or a phenyl group. 6. In the formula (I), the paint composition according to claim 1, wherein the proportion of the alkyl group having 1 to 6 carbon atoms among all of R 2 is 80% or more. 7. In the formula (I), the paint composition according to claim 1, wherein a satisfies 0 < a ≦ 1. 8. In the formula (I), the paint composition according to claim 1, wherein d is 0. 9. The kinematic viscosity of the component (C) at 25°C is 1 to 200 mm2 The coating composition according to claim 1, which is / s 10. The coating composition according to claim 1, further comprising (D) a curing catalyst 11. A method for producing a coating composition according to any one of claims 1 to 10, wherein the components (A) to (C) are mixed at 10 to 40°C 12. A cured film formed from the coating composition according to any one of claims 1 to 10 13. A coated article having a substrate and the cured film according to claim 12 formed directly or via one or more other layers on at least one surface of the substrate 14. A method for forming a cured film on a substrate, comprising applying the coating composition according to any one of claims 1 to 10 directly or via one or more other layers on at least one surface of the substrate and then curing the coating composition is provided.

Advantages of the Invention

[0009] The coating composition of the present invention can be produced simply by mixing a polyol, a silane coupling agent having an isocyanurate skeleton, and a specific organopolysiloxane, and provides a cured film excellent in hardness, chemical resistance, antifouling property, and weather resistance, and thus is suitable for the production of various coated articles.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be specifically described. The coating composition of the present invention contains the following components (A) to (C). (A) Polyol (B) A silane coupling agent having an isocyanurate skeleton (C) An organopolysiloxane represented by the following formula (I)

Chemical formula

[0011] (1) (A) Polyol The polyol component (A) has two or more reactive hydroxyl groups in one molecule and, in the presence or absence of the curing catalyst, reacts with components (B) and (C), which have hydrolyzable silyl groups, to form a crosslinked structure.

[0012] Examples of polyols include acrylic polyols, which are (co)polymers of a (meth)acrylic monomer having a hydroxyl group and any other (meth)acrylic monomer; polyester polyols, which are condensation polymers of a polybasic acid and a polyhydric alcohol (including alkyd polyols, which are condensation polymers of a polybasic acid and a fatty acid and a polyhydric alcohol); and polyether polyols, which are addition polymers of a polyhydric alcohol and an alkylene oxide. Among these, acrylic polyols, polyester polyols, or both are preferred, and acrylic polyols are particularly preferred because they produce excellent transparency and gloss in the resulting coating film. In this specification, (meth)acrylic monomer includes both acrylic monomer and methacrylic monomer.

[0013] Specific examples of hydroxyl group-containing (meth)acrylic monomers that are raw material monomers for acrylic polyols include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl monobutyl fumarate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and various hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids such as "Praxel FM or Praxel FA" [caprolactone addition monomers manufactured by Daicel Chemical Corporation], or adducts of these with ε-caprolactone. Among these, 2-hydroxyethyl (meth)acrylate is preferred because it reacts easily.

[0014] Other (meth)acrylic monomers copolymerizable with hydroxyl group-containing (meth)acrylic monomers are not particularly limited, and known monomers can be used. Vinyl monomers are also copolymerizable. Specific examples include alkyl(meth)acrylates having alkyl groups with 1 to 22 carbon atoms, such as methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, tert-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and lauryl(meth)acrylate; aralkyl(meth)acrylates such as benzyl(meth)acrylate and 2-phenylethyl(meth)acrylate; cycloalkyl(meth)acrylates such as cyclohexyl(meth)acrylate and isobornyl(meth)acrylate; ω-alkoxyalkyl(meth)acrylates such as 2-methoxyethyl(meth)acrylate and 4-methoxybutyl(meth)acrylate; and aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene, and vinyltoluene. Examples include vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl pivalate, and vinyl benzoate; alkyl esters of crotonic acids such as methyl crotate and ethyl crotate; dialkyl esters of unsaturated dibasic acids such as dimethyl malate, di-n-butyl malate, dimethyl fumarate, and dimethyl itaconate; α-olefins such as ethylene and propylene; fluoroolefins such as vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene; alkyl vinyl ethers such as ethyl vinyl ether and n-butyl vinyl ether; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether; and monomers containing tertiary amide groups such as N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-(meth)acryloylpyrrolidine, and N-vinylpyrrolidone.

[0015] The polymerization method, solvent, and polymerization initiator used when copolymerizing these monomers are not particularly limited. For example, polymerization can be carried out using various polymerization methods such as bulk radical polymerization, solution radical polymerization, and non-aqueous dispersion radical polymerization, with solvents such as hydrocarbons like hexane, octane, toluene, and xylene; ketones like methyl ethyl ketone; esters like ethyl acetate; and alcohols like isopropyl alcohol, as needed, and with polymerization initiators such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, and diisopropyl peroxycarbonate.

[0016] The molecular weight of the polyol of component (A) is not particularly limited, but from the viewpoint of curability, weather resistance and paintability, the weight-average molecular weight (Mw) in terms of polystyrene in gel permeation chromatography is preferably 1,000 to 100,000, and more preferably 2,000 to 80,000. The amount of hydroxyl groups contained in component (A) is not particularly limited, but a hydroxyl value of 10 to 200 mg KOH / g is preferred, and 20 to 180 mg KOH / g is more preferred. In this invention, the hydroxyl value is the value according to JIS K 0070:1992.

[0017] (A) As for the component, commercially available products can be used, for example, Acrydic A-801P (acrylic polyol), Acrydic 53-580 (acrylic polyol), and Barnock D-220 (polyester polyol) (all manufactured by DIC Corporation). Furthermore, component (A) may be used alone or in combination of two or more types.

[0018] (2)(B) Silane coupling agents having an isocyanurate skeleton Component (B) is a silane coupling agent having an isocyanurate skeleton and preferably having one or more hydrolyzable silyl groups or silanol groups in one molecule.

[0019] Examples of hydrolyzable silyl groups include trialkoxysilyl groups such as trimethoxysilyl and triethoxysilyl; organodialkoxysilyl groups such as methyldimethoxysilyl and ethyldiethoxysilyl; diorganoalkoxysilyl groups such as dimethylmonomethoxysilyl and diethylmonoethoxysilyl; and halosilyl groups such as trichlorosilyl, dichloromethylsilyl, and chlorodimethylsilyl. Among these, trialkoxysilyl groups such as trimethoxysilyl and triethoxysilyl are preferred, and trimethoxysilyl is more preferred.

[0020] Examples of silane coupling agents having an isocyanurate skeleton include the compound shown in the following formula (II).

[0021] [ka]

[0022] R 3 Each of these independently represents an alkylene group with 1 to 20 carbon atoms, and R 4 Each of these independently represents a substituted or unsubstituted monovalent hydrocarbon group with 1 to 12 carbon atoms, and R 5 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and f is independently 0, 1, or 2.

[0023] R 3 The alkylene group is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms. R 3The alkylene group can be either a straight chain or a branched chain, and specific examples include methylene, ethylene, trimethylene, propylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, tridecamethylene, tetradecamethylene, pentadecamethylene, hexadecamethylene, heptadecamethylene, octadecamethylene, nonadecamethylene, eicosadecylene, etc. Among these, R 3 The group is preferably a methylene, ethylene, or trimethylene group, with the trimethylene group being more preferred.

[0024] R 4 The monovalent hydrocarbon group may be linear, branched, or cyclic. Examples include alkyl groups having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms; alkenyl groups having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms; aryl groups having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 12 carbon atoms, preferably 7 to 10 carbon atoms. Specific examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Specific examples of alkenyl groups with 2 to 12 carbon atoms include vinyl and allyl groups. Specific examples of aryl groups with 6 to 12 carbon atoms include phenyl and naphthyl groups. Specific examples of aralkyl groups with 7 to 12 carbon atoms include benzyl and phenylethyl groups. Furthermore, some or all of the hydrogen atoms bonded to the carbon atoms of these monovalent hydrocarbon groups may be substituted with halogen atoms such as chlorine, fluorine, or bromine, or with other substituents such as cyano groups. Specific examples of these include halogen-substituted hydrocarbon groups such as chloromethyl, bromoethyl, trifluoropropyl, chlorophenyl, and bromophenyl groups; and cyano-substituted hydrocarbon groups such as cyanoethyl groups.

[0025] Among these, R 4 The preferred groups are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, phenyl, benzyl, and vinyl groups, with methyl, ethyl, and phenyl groups being more preferred.

[0026] R 5 The alkyl group is preferably one having 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and may be either a linear or branched chain. A specific example is R 4 Among the alkyl groups exemplified in the above, those with 1 to 8 carbon atoms are also included. Of these, those with 1 to 3 carbon atoms are preferred, and methyl and ethyl groups are more preferred.

[0027] f is 0, 1, or 2, with 0 being preferred.

[0028] (B) A specific example of component (B) is, for instance, 1,3,5-tris(3-trimethoxy). CTris(3-triethoxysilylpropyl) isocyanurate, 1,3,5-tris(3-triethoxysilylpropyl) isocyanurate, 1,3,5-tris(3-tripropoxysilylpropyl) isocyanurate, 1,3,5-tris(3-methyldimethoxysilylpropyl) isocyanurate, 1,3,5-tris(3-methyldiethoxysilylpropyl) isocyanurate, 1,3,5-tris(3-methyldipropoxysilylpropyl) isocyanurate, 1,3,5-tris(3-phenyldimethoxysilylpropyl) isocyanurate, 1,3,5-tris(3-phenyldiethoxysilylpropyl) isocyanurate, 1,3,5-tri Examples include tri(2-trimethoxysilylethyl) isocyanurate, 1,3,5-tris(2-triethoxysilylethyl) isocyanurate, 1,3,5-tris(2-tripropoxysilylethyl) isocyanurate, 1,3,5-tris(2-methyldimethoxysilylethyl) isocyanurate, 1,3,5-tris(2-methyldiethoxysilylethyl) isocyanurate, 1,3,5-tris(2-methyldipropoxysilylethyl) isocyanurate, 1,3,5-tris(2-phenyldimethoxysilylethyl) isocyanurate, 1,3,5-tris(2-phenyldiethoxysilylethyl) isocyanurate, and 1,3,5-tris(2-phenyldipropoxysilylethyl) isocyanurate. Among these, 1,3,5-tris(3-trimethoxy) C Ilylpropyl) isocyanurate and 1,3,5-tris(3-triethoxysilylpropyl) isocyanurate are preferred, and 1,3,5-tris(3-trimethoxy C Rylpropyl isocyanurate is more preferred.

[0029] (B) As for component (B), commercially available products may be used, for example, KBM-9659 (manufactured by Shin-Etsu Chemical Co., Ltd.), but is not limited to these. (B) Component may be used alone or in combination of two or more components.

[0030] (B) component is formulated in an amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the non-volatile content of (A) component. When the amount of (B) component is less than 0.5 parts by mass, the chemical resistance, antifouling property, and weather resistance of the resulting cured film are inferior. When the amount of (B) component exceeds 20 parts by mass, the hardness of the resulting cured film is inferior.

[0031] (3) (C) Organopolysiloxane (C) component is an organopolysiloxane having a siloxane unit composition ratio represented by the following formula (I).

[0032]

Chemical formula

[0033] R 1 each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, substituted or unsubstituted, and R 2 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a, b, c, d are numbers satisfying 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ c ≦ 0.5, 0 ≦ d < 1, a + b + c + d = 1, and 0.5 < (a + b) ≦ 1, and e is a number satisfying 0 < e ≦ 4.

[0034] R 1 The monovalent hydrocarbon group of may be linear, branched, or cyclic. For example, an alkyl group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms; an alkenyl group having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms; an aryl group having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms; an aralkyl group having 7 to 12 carbon atoms, preferably 7 to 10 carbon atoms, etc. can be mentioned. Specific examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl group, etc. Specific examples of the alkenyl group having 2 to 12 carbon atoms include vinyl, allyl group, etc. Specific examples of the aryl group having 6 to 12 carbon atoms include phenyl, naphthyl group, etc. Specific examples of the aralkyl group having 7 to 12 carbon atoms include benzyl, phenylethyl group, and the like. In addition, some or all of the hydrogen atoms bonded to the carbon atoms of these monovalent hydrocarbon groups may be substituted with halogen atoms such as chlorine, fluorine, bromine, and other substituents such as cyano groups. Specific examples thereof include halogen-substituted hydrocarbon groups such as chloromethyl, bromoethyl, trifluoropropyl, chlorophenyl, bromophenyl groups; cyano-substituted hydrocarbon groups such as cyanoethyl group, and the like.

[0035] Among these, R 1 is preferably a methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, phenyl, benzyl, vinyl group, and more preferably a methyl, ethyl, phenyl group. In addition, the above R 1 is preferably such that 20% or more of the total number of R 1 is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms which may be substituted with a halogen atom.

[0036] On the other hand, specific examples of the alkyl group having 1 to 6 carbon atoms of R 2 include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-hexyl group, and the like. Among these, those having 1 to 3 carbon atoms are preferred, and methyl and ethyl groups are more preferred. In addition, in the present invention, the proportion of the alkyl group having 1 to 6 carbon atoms in the total number of R 2 is preferably 80% or more, more preferably 90% or more, and even more preferably 100%.

[0037] a is a number satisfying 0 ≦ a ≦ 1, but from the viewpoint of the hardness of the obtained cured film, 0 < a ≦ 1 is preferred, and 0.5 ≦ a ≦ 1 is more preferred. b is a number satisfying 0 ≦ b ≦ 1, but from the viewpoint of the scratch resistance of the obtained cured film, 0.1 ≦ b ≦ 0.8 is preferred, and 0.2 ≦ b ≦ 0.6 is more preferred. c is a number satisfying 0 ≦ c ≦ 0.5. From the viewpoints of the curability of the composition and the hardness of the resulting cured film, 0 ≦ c ≦ 0.4 is preferable, and 0.1 ≦ c ≦ 0.3 is more preferable. d is a number satisfying 0 ≦ d < 1. From the viewpoints of the curability of the composition and the hardness of the resulting cured film, 0 ≦ d ≦ 0.4 is preferable, and 0 is more preferable. e is a number satisfying 0 < e ≦ 4. From the viewpoints of being effective in suppressing the condensation reaction by the condensable functional group, and the crack resistance, water resistance, and weather resistance of the resulting cured film, 0 < e ≦ 3 is preferable, and a number satisfying 0 < e ≦ 1 is more preferable. Note that a + b + c + d = 1, and a + b is a number satisfying 0.5 < (a + b) ≦ 1, preferably 0.7 ≦ (a + b) ≦ 1.

[0038] The component (C) can be produced according to a general method for producing an organopolysiloxane. For example, it can be obtained by hydrolytically condensing a silane compound having a hydrolyzable group. The silane compound having a hydrolyzable group contains 1 to 4 chloro or alkoxy groups, which are hydrolyzable groups, on the silicon atom, and is not particularly limited as long as it is a silane compound having an organic substituent satisfying the above conditions. Specific examples include tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiisopropoxysilane, trimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, ethyltrichlorosilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrichlorosilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrichlorosilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrichlorosilane, hexyltrimethoxysilane, hexyltriethoxysilane, phenyl Examples include trichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, cyclohexyltrichlorosilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, propylmethyldichlorosilane, propylmethyldimethoxysilane, propylmethyldiethoxysilane, hexylmethyldichlorosilane, hexylmethyldimethoxysilane, hexylmethyldiethoxysilane, phenylmethyldichlorosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, diphenyldichlorosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, dimethylphenylchlorosilane, dimethylphenylmethoxysilane, dimethylphenylethoxysilane, and partial hydrolysates thereof. However, due to ease of handling, ease of removing by-products, and availability of raw materials, methoxysilane and ethoxysilane are preferred. The silane compounds mentioned above may be used individually or in combination of two or more.

[0039] A hydrolysis catalyst may be used when carrying out hydrolysis. Conventional known catalysts can be used as hydrolysis catalysts, and those whose aqueous solution exhibits acidity with a pH of 1 to 7 are preferred, with particular preference being acidic hydrogen halides, sulfonic acids, carboxylic acids, acidic or weakly acidic inorganic salts, solid acids such as ion exchange resins, etc. Specific examples of acidic catalysts include hydrogen fluoride, hydrochloric acid, nitric acid, sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, formic acid, acetic acid, maleic acid, benzoic acid, lactic acid, phosphoric acid, and cation exchange resins having sulfonic acid or carboxylic acid groups on their surface. The amount of hydrolysis catalyst used is not particularly limited, but considering the need to allow the reaction to proceed rapidly and the ease of removing the catalyst after the reaction, a range of 0.0002 to 0.5 moles per mole of hydrolyzable silane is preferred.

[0040] The mass ratio of hydrolyzable silane to water required for the hydrolysis condensation reaction is not particularly limited, but considering the need to prevent catalyst deactivation and allow the reaction to proceed sufficiently, as well as the ease of removing water after the reaction, a ratio of 0.1 to 10 moles of water per mole of hydrolyzable silane is preferred. The reaction temperature during hydrolysis condensation is not particularly limited, but -10 to 150°C is preferred to improve the reaction rate and prevent the decomposition of the organic functional groups of the hydrolyzable silane.

[0041] Furthermore, organic solvents may be used during hydrolysis condensation. Specific examples of usable organic solvents include methanol, ethanol, propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, toluene, and xylene.

[0042] Furthermore, component (C) preferably has a non-volatile content of 85% by mass or more, excluding solvents, and more preferably 90% by mass or more. If the volatile content is too high, it may cause deterioration of the appearance due to void formation when the composition is cured, and a decrease in mechanical properties. The molecular weight of component (C) is not particularly limited, but it is preferable that its weight-average molecular weight (Mw) in terms of polystyrene in gel permeation chromatography is 500 to 10,000. The kinematic viscosity of component (C) is not particularly limited, but is between 1 and 200 mm. 2 / s is preferred, and 1 to 150 mm 2 / s is more preferable, 3-120mm 2 / s is even more preferable. The kinematic viscosity was measured at 25°C using a Cannon-Fenske viscometer in accordance with JIS-Z-8803.

[0043] The amount of component (C) is 5 to 100 parts by mass of nonvolatile content per 100 parts by mass of nonvolatile content of component (A), but 8 to 60 parts by mass is preferred. If the amount of component (C) is less than the above range, the weather resistance and stain resistance of the resulting cured film will be insufficient, while if it is too much, the chemical resistance, crack resistance and weather resistance will be insufficient. Furthermore, component (C) may be a single composition or a mixture of multiple compounds with different compositions. In particular, the composition of the present invention can be suitably produced by mixing multiple compounds with different average compositions.

[0044] (4)(D) Curing catalyst The coating composition of the present invention may contain a curing catalyst. The curing catalyst is not particularly limited as long as it is one that is commonly used in organosiloxane-based coatings, but organometallic compounds are preferred, such as metal alkoxide compounds of Ti, Al, Zr, Sn, etc., metal chelate compounds, metal ester compounds, etc., but those containing organotin compounds are preferred. Specific examples of metal alkoxide compounds include aluminum alkoxides such as aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide, aluminum tri-s-butoxide, and aluminum tri-t-butoxide; and tetramethyl titanate, tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-t-butyl titanate, tetra-n-hexyl titanate, and tetramethyl titanate. Examples include titanium alkoxides such as lyisooctyl titanate and tetra-n-lauryl titanate; zirconium alkoxides such as tetraethyl zirconate, tetra-n-propyl zirconate, tetraisopropyl zirconate, tetra-n-butyl zirconate, tetra-s-butyl zirconate, tetra-t-butyl zirconate, tetra-n-pentyl zirconate, tetra-t-pentyl zirconate, tetra-t-hexyl zirconate, tetra-n-heptyl zirconate, tetra-n-octyl zirconate, and tetra-n-stearyl zirconate; and tin alkoxides such as dibutyltin dibutoxide.

[0045] Specific examples of metal chelating compounds include tris(ethylacetacetate)aluminum, tris(n-propylacetate)aluminum, tris(isopropylacetate)aluminum, tris(n-butylacetate)aluminum, isopropoxybis(ethylacetate)aluminum, tris(acetylacetonato)aluminum, tris(propionylacetonato)aluminum, diisopropoxypropionylacetonatoaluminum, acetylacetonato-bis(propionylacetonato)aluminum, monoethylacetate-bis(acetylacetonato)aluminum, acetylacetonatoaluminum-di-s-butyrate, methylacetoacetatealuminum-di-s-butyrate, di(methylacetoacetate)aluminum-mono-tert-butyrate, and diisopropoxyethyl Examples include aluminum chelate compounds such as cetoacetate aluminum and monoacetylacetonato-bis(ethylacetoacetate)aluminum; titanium chelate compounds such as diisopropoxy-bis(ethylacetoacetate)titanate, diisopropoxy-bis(acetylacetonato)titanate, and di-n-butoxy-bis(acetylacetonato)titanate; zirconium chelate compounds such as tetrakis(acetylacetonato)zirconium, tetrakis(n-propylacetoacetate)zirconium, and tetrakis(ethylacetoacetate)zirconium; and tin chelate compounds such as tin ester compounds such as dibutyltin diacetate, dibutyltin di(2-ethylhexylate), dibenzyltin di(2-ethylhexylate), dibutyltin dilaurate, dibutyltin diisooctylmaleate, and dibutyltin bis(acetylacetonate). Among these, tin chelate compounds such as tin ester compounds are suitable in terms of the chemical resistance of the resulting coating film.

[0046] Commercially available tin ester compounds can be used as described above, including, for example, Neostan U-100, U-130, U-200, U-220H, U-303, U-700, U-810, U-820, U-830 (all manufactured by Nitto Chemical Co., Ltd.), and BT-120S (manufactured by Kaneka Corporation).

[0047] When component (D) is included, the amount included should be sufficient to cure the composition, but usually 0.01 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the nonvolatile content of component (A). Furthermore, the curing catalyst of component (D) may be used alone or in combination of two or more types.

[0048] (5) Optional ingredients The coating composition of the present invention may contain any additives as appropriate, as long as they do not impair the effects of the present invention. Specific examples of additives include solvents, non-reactive silicone oils, reactive silicone oils, adhesion promoters such as silane coupling agents other than component (B), non-reactive polymer resins, fillers, leveling agents, rheology modifiers, reactive diluents, non-reactive diluents, surfactants, dispersants, defoamers, dehydrators, antioxidants, antioxidants, antistatic agents, infrared absorbers, ultraviolet absorbers, light stabilizers, fluorescent agents, dyes, pigments, fragrances, abrasives, rust inhibitors, thixotropy promoters, and the like. These can be used individually or in combination of two or more types.

[0049] Examples of solvents include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbons such as hexane and octane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These may be used individually or in combination of two or more. When a solvent is added, the amount added is preferably 1 to 50 parts by mass, and more preferably 2 to 30 parts by mass, per 100 parts by mass of the total nonvolatile content of components (A) to (C).

[0050] Pigments include, for example, titanium dioxide, red iron oxide, cyanine-based coloring pigments, carbon black, zircon powder, and other coloring pigments; extender pigments such as silica, barium powder, precipitated barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, white carbon, diatomaceous earth, talc, magnesium carbonate, alumina white, gloss white, and calcium carbonate; and zinc phosphate, zinc phosphate-silicate, zinc aluminum phosphate, zinc calcium phosphate, and calcium phosphate. , Pi Calcium triphosphate, aluminum dihydrogen tripolyphosphate, aluminum metaphosphate, calcium metaphosphate , Examples of rust-preventive pigments include zinc molybdate, aluminum phosphomolybdate, zinc, zinc oxide, zinc molybdate, calcium molybdate, borate compounds, barium metaborate, zinc cyanamide calcium, calcium silicate, calcium metasilicate; modified silica obtained by bonding cations such as calcium, zinc, cobalt, lead, strontium, and barium to porous silica particles; ion-exchange silica obtained by bonding cations by ion exchange; and vanadium-based compounds such as aluminum pyrophosphate, vanadium pentoxide, calcium vanadate, and ammonium metavanadate. These may be used individually or in combination of two or more.

[0051] When a pigment is incorporated into the paint composition of the present invention, the amount of pigment incorporated is preferably 5 to 100 parts by mass, and more preferably 30 to 90 parts by mass, in terms of nonvolatile content, per 100 parts by mass of the total nonvolatile content of components (A) to (C), from the viewpoint of the weather resistance of the formed coating film.

[0052] (6) Manufacturing method The paint composition of the present invention can be obtained by mixing and stirring the above components (A), (B), (C), and optionally (D) and other optional components in any order. The mixing conditions are not particularly limited, but considering workability and the stability of the paint composition, it is preferable to mix at 10 to 40°C.

[0053] The viscosity of the paint composition of the present invention is not particularly limited, but considering the need to improve moldability or application workability and suppress the occurrence of unevenness, the viscosity at 25°C measured by a rotational viscometer is preferably 100,000 mPa·s or less, and more preferably 20,000 mPa·s or less. The lower limit of viscosity is not particularly limited, but is preferably 10 mPa·s or more.

[0054] (7) Cured films and coated articles of paint compositions A cured film and a coated article are obtained by applying the coating composition of the present invention to an object to be coated and curing it. There are no restrictions on the application method; for example, known methods such as spray application, roller application, brush application, and pour application can be used. The paint composition of the present invention is curable by heating, preferably at a heating temperature of 80 to 200°C, which allows the formed cured coating film to exhibit excellent hardness, chemical resistance, stain resistance, and weather resistance.

[0055] Examples of materials to be coated include glass and, if desired, pre-treated metal materials such as steel plates, galvanized steel plates, stainless steel, and aluminum; alkaline substrates such as concrete, mortar, slate, and slate tiles; ceramic building materials; plastics; and materials on which old paint films have been formed.

[0056] The applications of the paint composition of the present invention are not particularly limited, but include heavy-duty corrosion protection coatings for steel structures such as bridges, power transmission towers, plants, and tanks.

[0057] The paint composition of the present invention exhibits excellent long-term weather resistance and, on its own, provides a cured film that protects the coated object from harsh environments and maintains its aesthetic appearance. However, layers of known primers and / or intermediate coats may be provided as needed.

[0058] Examples of the above-mentioned primers include epoxy resin paints, modified epoxy resin paints, epoxy resin-based glass flake paints, epoxy resin coating materials, ultra-thick film epoxy resin paints, epoxy resin zinc-rich paints, inorganic zinc-rich paints, chlorinated rubber resin paints, phthalic acid resin paints, and epoxy ester resin paints. Examples of intermediate coats include epoxy resin paints, polyurethane paints, epoxy resin MIO paints, phenolic resin MIO paints, chlorinated rubber resin paints, and phthalic acid resin paints. [Examples]

[0059] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The hydroxyl value was measured by neutralization titration in accordance with JIS K 0070:1992, the weight-average molecular weight was measured using GPC (gel permeation chromatography, HLC-8220, manufactured by Tosoh Corporation) with tetrahydrofuran (THF) as the developing solvent, the non-volatile content was measured by the residual heat method after heating and drying on an aluminum petri dish at 105°C for 3 hours in accordance with JIS K 5601-1-2:2008, and the kinematic viscosity was measured at 25°C using a Cannon-Fenske viscometer. Furthermore, the composition ratio of each siloxane unit in component (C) below is: 1 H-NMR and 29 This was calculated from the results of Si-NMR measurements.

[0060] [1] Manufacturing of paint compositions [Examples 1-1 to 1-7, Comparative Examples 1-1 to 1-4] Paint compositions (i) to (xi) were prepared by mixing the following components at 25°C in the composition ratios (mass ratios) shown in Table 1. <(A) component> (A-1): Acrydic A-801P (Acrylic polyol, 50% by mass of non-volatile content, 50 mg KOH / g hydroxyl value, manufactured by DIC Corporation) (A-2): Barnock D-220 (polyester polyol, 100% by mass of non-volatile content, hydroxyl value 147 mg KOH / g, manufactured by DIC Corporation) <(B) component> (B): KBM-9659 (Tris-(trimethoxy) C (Rylpropyl) Isocyanurate (manufactured by Shin-Etsu Chemical Co., Ltd.) <(C) component> (C-1): In equation (I), a=0.8, b=0.2, c=0, d=0, e=0.26, R 1 =methyl group, phenyl group (R 1 The proportion of phenyl groups in the total number of R groups: 20%, 2 =Organopolysiloxane represented by methyl groups (non-volatile content: 87% by mass, weight-average molecular weight 1,000, kinematic viscosity at 25°C 5 mm²) 2 (Manufactured by Shin-Etsu Chemical Co., Ltd.) (C-2): In equation (I), a=0.1, b=0.6, c=0.3, d=0, e=0.24, R 1 =methyl group, phenyl group (R 1 The proportion of phenyl groups in the total number of R groups: 30%, 2 =Organopolysiloxane represented by methyl groups (non-volatile content: 96% by mass, weight-average molecular weight 1,800, kinematic viscosity at 25°C 100 mm) 2 (Manufactured by Shin-Etsu Chemical Co., Ltd.) <(D) component> (D): Neostan U-830 (Dioctyl tin, manufactured by Nitto Kasei Co., Ltd.) <(E) component> (E): Ethyl acetate / butyl acetate mixed solvent (mass ratio 1:1)

[0061] [Table 1]

[0062] [2] Manufacturing and evaluation of coated articles [Examples 2-1 to 2-7, Comparative Examples 2-1 to 2-4] The coating compositions (i) to (xi) obtained in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4 were applied to a metal substrate by flow coating to a dry film thickness of 30 μm, and the films were heated at 150°C for 1 hour to obtain the coatings. The obtained coated articles were evaluated for coating appearance, rubbing test, pencil hardness, stain resistance test, and accelerated weathering resistance. The results are shown in Table 2. (1) Appearance of the coating Visually, a coating surface that was uniform and free from unevenness or cracks caused by aggregates was marked with a circle (○), while a coating surface that was uneven and showed whitening, unevenness or cracks caused by aggregates was marked with a cross (×). (2) Rubbing test Acetone in Bencot M-3II (area 4cm²) 2 The sample was immersed in a solution (manufactured by Asahi Kasei Corporation), and the surface was rubbed back and forth 30 times under a load of 500 gf. After the rubbing test, the appearance of the coating film was evaluated visually. ○: No significant changes were observed compared to the appearance of the coating film before the test. △: Slight peeling and whitening were observed compared to the appearance of the coating before the test. ×: Significant peeling and whitening were observed compared to the appearance of the coating before the test. (3) Pencil hardness The hardness was measured under a 750g load in accordance with JIS K 5600-5-4. A hardness of F or higher was considered acceptable. (4) Stain resistance test On the test surface, draw lines with an oil-based marker (organic solvent type marker, product name: Macky Extra Fine, manufactured by Zebra Co., Ltd.), leave for 3 hours, then soak Benkot M-3II (area 4 cm²) in a mixed solvent of ethanol:toluene (mass ratio 1:1). 2 The test evaluated whether the ink could be wiped off using a product manufactured by Asahi Kasei Corporation. After the test, the amount of ink remaining on the coating was visually observed and evaluated on a three-point scale. ○: No significant changes are observed compared to the current test specimen. △: Slightly more ink remains compared to the current test piece. ×: Significantly more ink remains compared to the current test specimen. (5) Accelerated weather resistance The accelerated weathering test was conducted using an ultra-accelerated weathering tester (iSuper UV Tester, manufactured by Iwasaki Electric Co., Ltd.). Polyester-coated steel sheets (0.8 mm x 70 mm x 60 mm) were used as test specimens. The test conditions consisted of a 10-hour cycle consisting of 3 hours of irradiation (UV irradiation intensity 90 mW, black panel temperature 63°C, 70% RH), 4 hours of darkness (black panel temperature 63°C, 70% RH), and 3 hours of condensation (black panel temperature 30°C, 90% RH), and 30 cycles were performed. After the test, the blistering, cracking, peeling, and gloss changes of the coating film were observed visually and evaluated on a three-point scale. ○: No significant changes are observed compared to the current test specimen. △: Slightly less glossy compared to the current test specimen. ×: Compared to the current test specimen, there is significant loss of gloss, cracking, and peeling.

[0063] [Table 2]

[0064] As shown in Table 2, the cured films obtained in Examples 2-1 to 2-7 exhibit excellent chemical resistance, hardness, stain resistance, and weather resistance. On the other hand, the cured film of Comparative Example 2-1, which used a composition with an insufficient amount of component (B), exhibited insufficient chemical resistance, stain resistance, and weather resistance, while the coating film of Comparative Example 2-3, which used a composition with an excessive amount of component (B), showed inferior hardness. Furthermore, in the coating film of Comparative Example 2-2, which used a composition with an insufficient amount of component (C), chemical resistance, hardness, stain resistance, and weather resistance were insufficient. In the coating film of Comparative Example 2-4, which used a composition with an excessive amount of component (C), the coating film surface was uneven, resulting in poor chemical resistance and weather resistance.

Claims

1. (A) One or more polyols selected from the group consisting of acrylic polyols, polyester polyols, and polyether polyols: 100 parts by mass, (B) Silane coupling agent having an isocyanurate skeleton: 0.5 to 20 parts by mass, and (C) Organopolysiloxane represented by the following formula (I): 5 to 100 parts by mass 【Chemistry 1】 (In the formula, R 1 Each of these independently represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, R 2 (where a represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, a, b, c, and d are numbers satisfying 0 ≤ a ≤ 1, 0 ≤ b ≤ 1, 0 ≤ c ≤ 0.5, 0 ≤ d < 1, a + b + c + d = 1, and 0.5 < (a + b) ≤ 1, and e is a number satisfying 0 < e ≤ 4.) A paint composition containing the following:

2. The coating composition according to claim 1, wherein the component (A) is an acrylic polyol, a polyester polyol, or both thereof.

3. The paint composition according to claim 1, wherein the component (B) is a compound represented by the following formula (II). 【Chemistry 2】 (In the formula, R 3 Each of these independently represents an alkylene group with 1 to 20 carbon atoms, and R 4 Each of these independently represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, R 5 (where f represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and f is independently 0, 1, or 2.)

4. In the above formula (I), R 1 The paint composition according to claim 1, wherein each is independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms.

5. In the above formula (I), R 1 The paint composition according to claim 4, wherein each is independently a methyl group, an ethyl group, or a phenyl group.

6. In the above formula (I), R 2 The paint composition according to claim 1, wherein the proportion of alkyl groups having 1 to 6 carbon atoms among the total number of atoms is 80% or more.

7. The paint composition according to claim 1, wherein in formula (I), a is 0 < a ≤ 1.

8. The paint composition according to claim 1, wherein d in formula (I) is 0.

9. The paint composition according to claim 1, wherein the kinematic viscosity at 25°C of the component (C), measured by a Canon Fenske viscometer in accordance with JIS-Z-8803, is 1 to 200 mm 2 / s.

10. Furthermore, the paint composition according to claim 1, further comprising (D) a curing catalyst.

11. A method for producing a paint composition according to any one of claims 1 to 10, comprising mixing the components (A) to (C) at 10 to 40°C.

12. A cured film formed from the paint composition according to any one of claims 1 to 10.

13. A coated article having a substrate and a cured film according to claim 12 formed directly on at least one surface of the substrate or via one or more other layers.

14. A method for forming a cured film on a substrate, comprising applying the coating composition according to any one of claims 1 to 10 directly or via one or more other layers to at least one surface of the substrate, and then curing the coating composition.

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