Thermosetting coating composition and decorative film

Abstract

To provide a decorative film that has excellent three-dimensional moldability, chemical resistance, weather resistance, and adhesion and can be suitably used outdoors, and a thermosetting coating composition that makes it possible to make the decorative film.SOLUTION: A thermosetting coating composition contains a methacrylic copolymer having a hydroxy group, a silsesquioxane compound represented by the formula (1), and a curing agent having two or more isocyanate groups.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermosetting coating composition and a decorative film. [Background technology]

[0002] There is a method for decorating the surface of molded resin products made from plastics, metals, and various other materials by using a decorative film made with a specific hard coating agent on the surface of the molded product to impart a design to the surface or protect the surface (for example, Patent Document 1). Compared to conventional painting, this method improves productivity and can impart designs that are difficult to achieve with painting, and has therefore become popular in home appliances, personal computers, and automotive interiors. It is stated that such hard coatings are required to have excellent formability and abrasion resistance so that they can be molded into three dimensions, and for automotive interiors, they are required to have high sunscreen resistance.

[0003] Patent Document 2 proposes an integrally moldable laminate sheet having a top coat layer made of a cured resin layer that has excellent three-dimensional formability, scratch resistance, chemical resistance, and adhesion. It describes that the hydroxyl-containing copolymer in the resin layer, obtained by curing a resin composition consisting of a hydroxyl-containing copolymer and a polyisocyanate compound, has a hydroxyl value of 10 to 300 KOHmg / g, a weight-average molecular weight of 2,000 to 50,000, and a glass transition temperature (Tg) of 80°C or lower. However, these products have insufficient outdoor weather resistance and substrate adhesion of the surface protective layer.

[0004] Patent Document 3 describes that by combining a double-decker silsesquioxane having a radically polymerizable functional group with an acrylic resin, it is possible to suppress cure shrinkage during curing and obtain a cured film in which a decrease in hardness (scratch resistance) is suppressed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-186500 A [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-347179 [Patent Document 3] International Publication No. 2018 / 131565 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a decorative film that is excellent in three-dimensional formability, chemical resistance, weather resistance, and substrate adhesion and is suitable for outdoor use, and a thermosetting coating composition that can be used to produce this decorative film. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that a thermosetting coating composition comprising a (meth)acrylic copolymer having a hydroxyl group, a silsesquioxane compound represented by formula (1), and a curing agent having two or more isocyanate groups can solve the above-mentioned problems, and have completed the present invention. [Effects of the Invention]

[0008] The surface protective layer obtained from the thermosetting coating composition of the present invention exhibits excellent three-dimensional formability, chemical resistance, weather resistance, and substrate adhesion. As a result, when the surface protective layer is formed on a substrate film, a laminate having the above properties can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an example of a decorative film having a surface protective layer made of a cured product of the thermosetting coating material of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0011] The present invention includes the following items.

[0012] [1] A thermosetting coating composition comprising the following components (a) to (c): (a) (meth)acrylic copolymer having hydroxyl groups (b) A silsesquioxane compound represented by formula (1) TIFF0007803060000001.tif4496 In formula (1), R is alkylene having 1 to 10 carbon atoms, and at least one -CH2- may be replaced with -O-. (c) a curing agent having two or more isocyanate groups

[0013] [2] The thermosetting coating composition according to item [1], wherein the component (a) has a hydroxyl value of 50 to 200 mgKOH / g and a glass transition temperature of 50°C or higher.

[0014] [3] The thermosetting coating composition according to item [1] or [2], wherein component (c) is an aliphatic isocyanate or an alicyclic isocyanate.

[0015] [4] The thermosetting coating composition according to any one of items [1] to [3], wherein component (c) is an isocyanate having an isocyanuric skeleton.

[0016] [5] The thermosetting coating composition according to any one of items [1] to [4], wherein the weight ratio of the component (a) to the component (b) is 95:5 to 50:50.

[0017] [6] The thermosetting coating composition according to any one of items [1] to [5], wherein the amount of isocyanate groups in component (c) is 0.5 to 1.5 molar equivalents relative to the total amount of hydroxyl groups in component (a) and component (b).

[0018] [7] An article having a surface protective layer made of a cured product of the thermosetting coating composition according to any one of items [1] to [6].

[0019] [8] A laminated film having a surface protective layer made of a cured product of the thermosetting coating composition according to any one of items [1] to [6] and a substrate layer.

[0020] [9] A decorative film using the laminated film according to item [8].

[0021] <Thermosetting Coating Composition> The thermosetting coating composition of the present invention contains the following components (a) to (c): (a) (meth)acrylic copolymer having hydroxyl groups (b) A silsesquioxane compound represented by formula (1) TIFF0007803060000002.tif4496In formula (1), R is alkylene having 1 to 10 carbon atoms, and at least one -CH2- may be replaced with -O-. (c) a curing agent having two or more isocyanate groups

[0022] <Component (a): (meth)acrylic copolymer having hydroxyl groups> The (meth)acrylic copolymer (a) having a hydroxyl group used in the present invention is obtained by copolymerizing an addition-polymerizable monomer having a hydroxyl group with another addition-polymerizable monomer. Examples of the addition-polymerizable functional group include a group having a terminal olefin-type or internal olefin-type radical-polymerizable functional group; a group having a cation-polymerizable functional group such as vinyl ether or propenyl ether; and a group having an anion-polymerizable functional group such as vinyl carboxyl or cyanoacryloyl, with the radical-polymerizable functional group being preferred.

[0023] The radically polymerizable functional group is not particularly limited as long as it is a radically polymerizable group, and includes, for example, (meth)acrylic, allyl, styryl, α-methylstyryl, vinyl, vinyl ether, vinyl ester, acrylamide, methacrylamide, N-vinylamide, maleic acid ester, fumaric acid ester, and N-substituted maleimide, and among these, a group containing (meth)acrylic is preferred. Here, (meth)acrylic is a general term for acrylic or methacrylic, and means acrylic or methacrylic. The same applies hereinafter.

[0024] Examples of the addition-polymerizable monomer having a hydroxyl group that can be used in the (meth)acrylic copolymer (a) of the present invention include hydroxyl-containing polymerizable unsaturated compounds such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 1,4-cyclohexanedimethanol monoacrylate, as well as adducts of hydroxyl-containing (meth)acrylic monomers with lactones such as ε-caprolactone (for example, Daicel Corporation's trade names "PLACCEL FA-1," "PLACCEL FA-3," "PLACCEL FM-1," and "PLACCEL FM-3"). One or more of these addition-polymerizable monomers having a hydroxyl group can be used as needed.

[0025] The addition polymerizable monomer other than the addition polymerizable monomer having a hydroxyl group used in the (meth)acrylic copolymer (a) of the present invention is not particularly limited, and may be any compound that can be copolymerized relatively easily. Such compounds are polymerizable unsaturated compounds substituted with a linear, branched, or cyclic saturated or unsaturated hydrocarbon having 1 to about 20 carbon atoms, and specific examples of the (meth)acrylic acid compound include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. ) acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and toluyl (meth)acrylate; aryl alkyl (meth)acrylates such as benzyl (meth)acrylate; alkoxy alkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate and 3-methoxybutyl (meth)acrylate; ethylene oxide adducts of (meth)acrylic acid; and (meth)acrylates having an alicyclic hydrocarbon group such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate and dicyclopentanyl (meth)acrylate.

[0026] Specific examples of the (meth)acrylic acid compound of an addition polymerizable monomer other than the above-mentioned addition polymerizable monomer having one addition polymerizable double bond and containing a hydroxyl group further include (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and 4-hydroxybutyl acrylate glycidyl ether; trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, and 2-perfluoroethylethyl (meth)acrylate. and fluoroalkyl (meth)acrylates such as perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate. One or more addition polymerizable monomers other than these hydroxyl group-containing addition polymerizable monomers can be used as needed.

[0027] The method for polymerizing the (meth)acrylic copolymer (a) having a hydroxyl group can be any known method such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc. Among these methods, the solution polymerization method is preferred because it allows the desired polymer to be obtained easily.

[0028] The solution polymerization method involves reacting the monomer components described above with an azo compound such as 2,2'-azobis-(2-methylbutyronitrile) or 2,2'-azobisisobutyronitrile, an organic peroxide such as tert-butylperoxy-2-ethylhexanoate, benzoyl peroxide or di-tert-butyl peroxide, or a chain transfer agent such as n-dodecyl mercaptan in an organic solvent containing aromatic hydrocarbons such as xylene or toluene, alcohols such as isopropanol or propylene glycol monomethyl ether, ketones such as cyclohexanone, methyl ethyl ketone or methyl isobutyl ketone, or esters such as ethyl acetate, butyl acetate or propylene glycol monomethyl acetate at a reaction temperature of 60 to 160°C for approximately 1 to 30 hours. However, the present invention is not limited to the above examples.

[0029] The (meth)acrylic copolymer (a) having a hydroxyl group may be used alone or in combination of two or more.

[0030] The glass transition temperature (hereinafter abbreviated as Tg) of the (meth)acrylic copolymer (a) having a hydroxyl group of the present invention, calculated by the Fox formula, is preferably 50° C. or higher from the viewpoint of heat moldability.

[0031] The hydroxyl value of the hydroxyl-containing copolymer (a) of the present invention is preferably 50 mgKOH / g to 200 mgKOH / g or more, more preferably 80 to 150 mgKOH / g, in which case the crosslink density of the polymer is improved and the chemical resistance is improved.

[0032] <Component (b): Silsesquioxane compound> The silsesquioxane compound used in the present invention is a double-decker silsesquioxane compound having a terminal hydroxyl group, represented by formula (1). The terminal hydroxyl group allows a crosslinked structure to be formed with the (meth)acrylic copolymer (a) and the curing agent (c) having two or more isocyanate groups, thereby imparting high weather resistance, particularly substrate adhesion. TIFF0007803060000003.tif53116

[0033] In the silsesquioxane compound represented by formula (1), R is alkylene having 1 to 10 carbon atoms, and at least one -CH2- may be replaced with -O-.

[0034] From the viewpoint of chemical resistance, the weight ratio of the (meth)acrylic copolymer (a) to the silsesquioxane compound (b) is preferably 95:5 to 50:50, more preferably 95:5 to 70:30. Within this range, sufficient alkali resistance is obtained.

[0035] The compound represented by formula (1) can be produced by referring to the method described in, for example, WO 2004 / 024741. The starting compound can be easily produced in high yield by hydrolyzing and polycondensing a silicon compound having three hydrolyzable groups in an oxygen-containing organic solvent such as tetrahydrofuran (hereinafter referred to as THF) or alcohol in the presence of an alkali metal hydroxide. Many silicon compounds having three hydrolyzable groups are commercially available. Compounds that are not commercially available can be synthesized by known techniques (e.g., reaction of a halogenated silane with a Grignard reagent). The starting compound represented by formula (2) can be obtained by polycondensation of triphenylsilane. The synthesis of formula (2) can also be carried out by reference to the method described in International Publication No. 03 / 024870.

[0036] TIFF0007803060000004.tif73127M is a monovalent alkali metal atom. Examples of alkali metal atoms include lithium, potassium, sodium, and cesium, with sodium being preferred.

[0037] One method for producing compound (1) from compound (2) is to first react compound (2) with dimethylchlorosilane to form (3), and then subject this to a hydrosilylation reaction with a compound having a hydroxyl group and a terminal unsaturated hydrocarbon group, such as allyl alcohol, to introduce a terminal hydroxyl group.

[0038] TIFF0007803060000005.tif71122

[0039] In the reaction of compound (2) with dimethylchlorosilane, an organic solvent is preferably used. Specifically, compound (2) is mixed with an organic solvent, and dimethylchlorosilane is added dropwise to this mixture. After the reaction is complete, the dimethylchlorosilane is removed by distillation, if necessary, and water is added to dissolve the alkali metal chloride by-product. The organic layer is then washed with water and dried with a dehydrating agent, after which the solvent is removed from the organic layer by distillation to obtain compound (3). The purity of compound (3) can be improved by recrystallization, if necessary, or by extracting impurities with an organic solvent.

[0040] The solvent used in the reaction is selected on the condition that it does not inhibit the progress of the reaction, and other than that, there are no particular limitations. Preferred solvents are aliphatic hydrocarbons (hexane, heptane, etc.), aromatic hydrocarbons (benzene, toluene, xylene, etc.), ethers (diethyl ether, THF, 1,4-dioxane, etc.), halogenated hydrocarbons (methylene chloride, carbon tetrachloride, etc.), and esters (ethyl acetate, etc.). These solvents may be used alone or in combination. More preferred solvents are aromatic hydrocarbons and ethers, and even more preferred solvents are toluene and THF. Furthermore, solvents with extremely low content of impurities (e.g., water) that readily react with dimethylchlorosilane are preferred.

[0041] The preferred ratio of compound (2) when mixed in a solvent is 0.05 to 50 wt % based on the weight of the solvent. To prevent the concentration of by-product salts from becoming so high that it inhibits the progress of the reaction, this ratio is preferably 50 wt % or less. To prevent volumetric efficiency from becoming so poor that it adversely affects costs, this ratio is preferably 0.05 wt % or more. A more preferred ratio is 1 to 10 wt %. There are no limitations on the amount of dimethylchlorosilane used, other than a molar ratio of 4 or more relative to compound (2). However, considering post-treatment processes, using a large excess is undesirable. The reaction temperature may be room temperature, or heating may be used as needed to promote the reaction. Cooling may be used if necessary to control the heat generated by the reaction or undesirable reactions.

[0042] This reaction can be easily accelerated by adding an amino-containing compound such as triethylamine or a basic organic compound. When triethylamine is used, the preferred addition ratio of triethylamine is 0.005 to 10 wt %, more preferably 0.01 to 3 wt %, based on the weight of the solvent. However, there is no particular limitation on the addition ratio of triethylamine, etc., as long as it can easily promote the reaction.

[0043] Compound (1) can be obtained by selecting one compound containing a hydroxyl group and a terminal unsaturated hydrocarbon group and subjecting it to a hydrosilylation reaction with compound (3). Compound (3) is mixed with an organic solvent and, if necessary, a hydrosilylation catalyst, and the compound containing a hydroxyl group and a terminal unsaturated hydrocarbon group is added dropwise to this mixture. Compound (1) can be obtained by removing the solvent from the organic layer. The purity of compound (1) can also be improved by recrystallization, if necessary, or by extracting impurities with an organic solvent.

[0044] The solvent used in the hydrosilylation reaction is selected on the condition that it does not inhibit the progress of the reaction, and there are no other particular limitations. Examples of preferred solvents are the same as the examples of solvents used in the reaction of compound (2) with dimethylchlorosilane, and they may be used alone or in combination of two or more. More preferred solvents are aromatic hydrocarbons, and toluene is most preferred among them.

[0045] When compound (3) is reacted with a compound having a hydroxyl group and a terminal unsaturated hydrocarbon group, the ratio of compound (3) to the solvent is preferably 0.05 to 80% by weight based on the weight of the solvent. A more preferred ratio is 30 to 70% by weight. There are no limitations on the ratio of the compound having a hydroxyl group and a terminal unsaturated hydrocarbon group to compound (3), except that the molar ratio relative to compound (3) must be 4 or more. However, considering the post-treatment process, it is undesirable to use a large excess.

[0046] The reaction temperature may be room temperature. Heating may be performed as needed to promote the reaction. Cooling may be performed if necessary to control the heat generated by the reaction or undesirable reactions. If necessary, the reaction can be made to proceed more easily by adding a hydrosilylation catalyst. Examples of preferred hydrosilylation catalysts include Karstedt's catalyst, Spier's catalyst, and Wilkinson's catalyst, which are generally well-known catalysts. These hydrosilylation catalysts are highly reactive, so adding a small amount is sufficient to promote the reaction. Usually, the transition metal contained is 10 times the amount of hydrosilyl. -9 The amount of addition is preferably 10 to 1 mol %. -7 ~10 -3 The amount of catalyst required to proceed with the reaction and complete it within an acceptable time is 10 mole percent of the transition metal relative to the hydrosilyl. -9 In order to keep production costs low, the amount of catalyst added must be such that the transition metal content is 1 mol % or less relative to the hydrosilyl.

[0047] Examples of compounds having a hydroxyl group and a terminal unsaturated hydrocarbon group include allyl alcohol, 3-buten-1ol, 2-methyl-3-buten-1ol, 4-penten-1-ol, 2-methyl-4-penten-1-ol, 3-methyl-4-penten-1-ol, 3-methyl-4-penten-2-ol, 4-methyl-1-penten-3-ol, 2,2-dimethyl-3-buten-1ol, 3,3-dimethyl-2-methylene-1-butanol, ethylene glycol monoallyl ether, ethylene glycol monovinyl ether, 1-(2-propen-1-yloxy)-1-propanol, 1-(2-propen-1-yloxy)-2-propanol, 2-(3-buten-1-yloxy)-ethanol, and 2-[2-(2-propen-1-yloxy)ethoxy]-ethanol.

[0048] The structure of the obtained compound can be analyzed by nuclear magnetic resonance (NMR) and matrix-assisted laser desorption / ionization (MALDI-TOF MS) as described in the Examples below. The silsesquioxane skeleton can also be analyzed by 29Si NMR.

[0049] <Component (c): Curing agent having an isocyanate group> The curing agent having two or more isocyanate groups used in the present invention has two or more isocyanate groups in one molecule, thereby forming a crosslinked structure between the (meth)acrylic copolymer (a) having a hydroxyl group and the silsesquioxane compound (b). Examples include aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates. Among these, aliphatic isocyanates or alicyclic isocyanates are preferred from the viewpoint of outdoor weather resistance. The curing agent (c) having an isocyanate group may be one type, or two or more types may be used.

[0050] Examples of aromatic isocyanates include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), naphthylene diisocyanate (NDI), paraphenylene diisocyanate (PPDI), and tetramethylxylylene diisocyanate (TMXDI).

[0051] Examples of the aliphatic isocyanate include hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), and trimethylhexamethylene diisocyanate.

[0052] Examples of alicyclic isocyanates include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), and 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI).

[0053] From the viewpoint of toxicity and the like, it is preferable to use these isocyanate compounds as adduct modified products, allophanate modified products, isocyanurate modified products, or biuret modified products of the above isocyanate and trimethylolpropane.

[0054] The adduct modified with trimethylolpropane is a compound obtained by modifying the above isocyanate with trimethylolpropane. The allophanate modified compound is produced by adding an isocyanate group to a urethane group. The isocyanurate modified compound is a compound having an isocyanurate ring in the molecule. The biuret modified compound is a compound in which an isocyanate group is added to a urea bond.

[0055] Among these isocyanate compounds, aliphatic or alicyclic trimethylolpropane adduct-modified compounds and isocyanurate-modified compounds are preferred from the viewpoint of the strength of the cured coating film, and isocyanurate-modified compounds are more preferred from the viewpoint of weather resistance. More specifically, isocyanurate-modified compounds of pentamethylene diisocyanate and isocyanurate-modified compounds of hexamethylene diisocyanate are preferred.

[0056] The isocyanurate of hexamethylene diisocyanate may be a commercially available product, such as "Coronate 2357" (manufactured by Tosoh Corporation), "Sumidur N3300" (manufactured by Sumika Covestro Urethane Co., Ltd.), "Duranate TPA-100" (manufactured by Asahi Kasei Corporation), "Takenate D170N" and "Takenate D177N" (both manufactured by Mitsui Chemicals, Inc.), and "Barnock DN-980" (manufactured by DIC Corporation). An example of the isocyanurate of pentamethylene diisocyanate is "Takenate D-370N" (manufactured by Mitsui Chemicals, Inc.).

[0057] The above isocyanate compounds can also be used as blocked isocyanates by reacting them with a blocking agent, such as phenol-based blocking agents such as phenol and xylenol, oximes, lactams, alcohols, active hydrogen compounds such as pyrazole, and active methylene compounds such as malonic acid esters.

[0058] In the present invention, the amount of isocyanate groups in the curing agent (c) having an isocyanate group is preferably 0.5 to 1.5 molar equivalents, more preferably 0.8 to 1.2 molar equivalents, relative to the total amount of hydroxyl groups in the (meth)acrylic copolymer (a) having a hydroxyl group and the silsesquioxane compound (b).Within this range, the coating film has sufficient curability and chemical resistance.

[0059] Catalyst (d) can be used to promote the curing of the thermosetting coating composition of the present invention. Examples of catalyst (d) include organotin compounds such as dibutyltin dilaurate, organotitanium compounds such as tetra-n-butyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetraoctyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetoacetate, and titanium ethylacetoacetate, organozirconium compounds such as tetra-n-butyl zirconate, n-propyl zirconate, and zirconium tetraacetylacetonate, amine compounds such as triethylamine and diazabicycloundecene, and organoaluminum compounds such as tris(acetylacetonato)aluminum and tris(ethylacetonato)aluminum.

[0060] In addition to the above, additives (e) may be added to the coating material. For example, fillers may be added to impart hardness and scratch resistance to the coating film. Leveling agents may be added to improve application properties. Other additives such as weathering agents and antifoaming agents may also be added. More specifically, the coating material may further contain optional components such as polymerization inhibitors, leveling agents (surface conditioners), wettability improvers, surfactants, plasticizers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, silane coupling agents, inorganic fillers such as silica and alumina, and organic fillers, as long as they do not adversely affect the effects of the film formed by the coating material.

[0061] Examples of leveling agents that can be used include commercially available acrylic surface conditioners such as BYK-342, BYK-350, BYK-352, BYK-354, BYK-356, BYK-381, BYK-392, BYK-394, BYK-3441, BYK-3440, and BYK-3550 (all trade names manufactured by BYK Japan Co., Ltd.). As an example of a leveling agent, commercially available silicone surface conditioners can be used, such as BYK-UV3500, BYK-UV-3570 (both trade names: manufactured by BYK Japan Co., Ltd.), and TEGO Examples of suitable acrylic resins include Rad2100, 2200N, 2250, 2500, 2600, and 2700 (all trade names: manufactured by Evonik Degussa Japan Co., Ltd.), X-22-2445, X-22-2455, X-22-2457, X-22-2458, X-22-2459, X-22-1602, X-22-1603, X-22-1615, X-22-1616, X-22-1618, X-22-1619, X-22-2404, X-22-2474, X-22-174DX, X-22-8201, X-22-2426, X-22-164A, and X-22-164C (all trade names: manufactured by Shin-Etsu Chemical Co., Ltd.).

[0062] Examples of weatherproofing agents include ultraviolet absorbers such as benzotriazoles, hydroxyphenyltriazines, and benzophenones. Examples of benzotriazoles include TINUVIN PS, TINUVIN 99-2, TINUVIN 326, TINUVIN 384-2, TINUVIN 900, TINUVIN 928, TINUVIN 1130, and TINUVIN Carboprotect, all manufactured by BASF; examples of hydroxyphenyltriazines include TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 477, and TINUVIN 479, all manufactured by BASF; and examples of benzophenones include 1413, manufactured by ADEKA Corporation, and Sumisorb 130, manufactured by Sumika Chemtex Corporation. These ultraviolet absorbents may be used alone or in combination, and it is preferable to appropriately select the type and combination of ultraviolet absorbents based on the wavelength of ultraviolet light to be absorbed.

[0063] Furthermore, examples of light stabilizers (HALS) include BASF's TINUVIN (registered trademark) 5100 (a neutral general-purpose HALS), TINUVIN 292 (compound name: bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate), and TINUVIN 152 (compound name: 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate]). TINUVIN 144 (compound name: bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate), TINUVIN 123 (compound name: decanedioic acid, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4piperidine) Reaction products of N-N'-N''-N''-tetrakis(4,6-bis(butyl-2,2,6,6-tetramethylpiperidinyl)-2-methylpropanol) esters (in the presence of 1,1-dimethylethyl hydroperoxide and octane), TINUVIN 111FDL (approximately 50%), TINUVIN 622 (compound name: butanedioic acid polymer (4-hydroxy-2,2,6,6-tetramethylpiperidinyl-yl)ethanol), approximately 50%, CHIMASSORB 119 (compound name: N-N'-N''-N'''-tetrakis(4,6-bis(butyl-2,2,6,6-tetramethylpiperidinyl)-2-methylpropanol), approximately 50%. (2,2,6,6-tetramethylpiperidin-4-yl)amino)triazin-2-yl)-4,7-diazadecane-1,10-diamine), or the Adeka STAB LA series manufactured by Adeka Corporation, specifically LA-52 ((5)-6116), LA-57 ((5)-5555), LA-62 ((5)-5711), LA-67 ((5)-5755), LA-82 ((5)-6023), and LA-87 ((5)-6022). The numbers in parentheses are the numbers of existing chemical substances.

[0064] Examples of inorganic fillers that can be used include silica, alumina, zirconium, titania, etc. Examples of such inorganic fillers include MEK-ST, MEK-ST-L, MEK-ST-40, MEK-ST-ZL, MEK-ST-UP, IPA-ST, IPA-ST-L, and IPA-ST-UP manufactured by Nissan Chemical Industries, Ltd., BYK-3601, BYK-3602, BYK-3610, and BYK-3611 manufactured by BYK-Chemie Japan, and MHI series FM-215M manufactured by Mikuni Pigment Co., Ltd. Examples of organic fillers include Techpolymer MBX series and SBX series manufactured by Sekisui Chemical Industries, Art Pearl cross-linked acrylic beads and Art Pearl cross-linked urethane beads manufactured by Negami Chemical Industries, and Ganz Pearl manufactured by Aica Kogyo. These fillers may be used alone or in combination.

[0065] The components (a), (b), (c), (d), and (e) contained in the thermosetting coating composition of the present invention may be dissolved in a solvent such as an organic solvent. The solvent is not particularly limited, and a general organic solvent can be used. Specific examples of solvents include hydrocarbon solvents (benzene, toluene, etc.), ether solvents (diethyl ether, tetrahydrofuran, diphenyl ether, anisole, dimethoxybenzene, propylene glycol monomethyl ether, propylene glycol monomethyl acetate, etc.), halogenated hydrocarbon solvents (methylene chloride, chloroform, chlorobenzene, etc.), ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), alcohol solvents (methanol, ethanol, propanol, isopropanol, butyl alcohol, t-butyl alcohol, etc.), nitrile solvents (acetonitrile, propionitrile, benzonitrile, etc.), ester solvents (ethyl acetate, butyl acetate, methyl 2-hydroxyisobutyrate, etc.), carbonate solvents (ethylene carbonate, propylene carbonate, etc.), and amide solvents (N,N-dimethylformamide, N,N-dimethylacetamide). These may be used alone or in combination of two or more.

[0066] The amount of solvent added is preferably such that the solid content of the thermosetting coating composition is 10 to 90% by weight, more preferably 15 to 40% by weight.

[0067] <Use of Thermosetting Coating Composition> By applying the thermosetting coating composition of the present invention to the surface of various articles and then drying and heating it, a surface protective layer can be formed that imparts weather resistance, chemical resistance, and adhesion to the surface of the article. While there are no particular limitations on the articles on which a surface protective layer can be formed, laminate films are particularly advantageous in that the liquid thermosetting coating composition of the present invention can be easily applied. Furthermore, among laminate films, decorative films that require formability are particularly useful as articles that utilize a surface protective layer. As shown in Figure 1, when a coating material is applied to a substrate layer 2 and cured, a surface protective layer 1 with excellent formability, weather resistance, chemical resistance, and adhesion can be formed. The laminated film provided with the surface protective layer will be described below.

[0068] <Surface protective layer> Treatments for curing thermosetting coating compositions typically include curing treatments such as heat aging. Curing treatment by heat aging is necessary to promote the reaction between the (meth)acrylic copolymer (a) having a hydroxyl group, the silsesquioxane compound (b) and the curing agent (c) having an isocyanate group. When the coating film contains a solvent, it is preferable to heat the coating film for several minutes at a temperature typically within the range of about 50 to 200°C, remove any remaining solvent, and then perform the curing treatment. Curing treatment by heat aging is typically performed for about 1 to 10 days in an environment between room temperature and about 100°C. While the aging temperature may be set to 100°C or higher to complete the aging process in a short time, it is preferable to perform aging at a low temperature in consideration of heat damage to the substrate layer. The thickness of the surface protective layer is generally 1 to 100 μm, preferably 2 to 50 μm, and more preferably 3 to 30 μm.

[0069] <Base material layer> The substrate layer is preferably a film formed of a thermoplastic resin. Examples of thermoplastic resins include polyurethane resins, polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and norbornene resins. One or more types of thermoplastic resins may be laminated. Polyester resins, polyolefin resins, (meth)acrylic resins, and polycarbonate resins are particularly preferred. These substrate films may also be laminated with multiple types of resins, such as a PMMA / PC two-layer film obtained by co-extrusion of a polycarbonate resin and a (meth)acrylic resin. The thickness of the substrate film is not particularly limited, but when the present invention is used as a laminate, the thickness of the substrate film is preferably 25 to 1000 μm, more preferably 100 to 400 μm. When the thickness of the substrate film is 25 μm or more, the mechanical strength of the substrate is sufficient, making it possible to form a layer on the substrate. Furthermore, when the thickness is 1000 μm or less, the thickness of the laminate does not become too thick.

[0070] <Laminated film manufacturing> The laminated film of the present invention can be obtained by applying a surface protective layer to a substrate layer and curing the layer by the above-described method, such as gravure coating, bar coating, spray coating, spin coating, roll coating, die coating, knife coating, air knife coating, hot melt coating, or curtain coating.

[0071] <Manufacturing decorative films> The decorative film of the present invention can be used to impart design features to the surface of molded articles made from plastic, metal, and various other materials, or to protect the surface. A surface protective layer may be applied to a substrate layer such as the laminate film described above, or a printed layer may be further provided to impart design features. The printed layer includes various decorations such as metallic tones, letters, pictures, and patterns. The printed layer can be provided on the surface of the substrate layer opposite the surface protective layer. Such decorative films can be used, for example, in film insert molding, laminate injection press molding, film in-mold molding, TOM molding, vacuum molding, and the like. [Example]

[0072] The present invention will be described in more detail below with reference to specific experimental examples, but the present invention is not limited to the following embodiments. Unless otherwise specified, measurements were carried out at 23°C.

[0073] <Synthesis example> The instruments used in the synthesis examples are as follows. <Equipment used> Gel permeation chromatography (GPC): Japan Analytical Industry Co., Ltd. Column: Showa Denko Shodex KF804L, Shodex KF805L, two connected in series Mobile phase: THF Flow rate: 0.5ml / min Temperature: 40℃ Detector: Differential Refractive Index (RI) Molecular weight standard sample: Polymethyl methacrylate resin with known molecular weight (manufactured by Showa Denko K.K.) Nuclear magnetic resonance (NMR): manufactured by VARIAN Equipment name: VARIAN NMR SYSTEM (500MHz) Matrix-assisted laser desorption / ionization (MALDI-TOF MS): BRUKER DALTONICS Equipment name:Bruker Daltonics autoflexIII Matrix: 2,5-dihydroxybenzoic acid (2,5-DHB) Ionizing agent: Sodium trifluoroacetate (NaTFA) Formulation (molar ratio): 2,5-DHB / NaTFA / Sample=100 / 10 / 1 Measurement: Linear Positive mode (measurement range: m / z = 1000 to 3000)

[0074] <Synthesis Example (a1) "Acrylic Copolymer (a1)"> A 200 mL four-neck flask equipped with a reflux condenser, thermometer, and dropping funnel was charged with 10.50 g of 2-hydroxyethyl methacrylate (HEMA), 24.50 g of methyl methacrylate (MMA), and 59.66 g of ethyl acetate. The flask was then placed in an oil bath maintained at 90°C under a nitrogen atmosphere and refluxed for 15 minutes. Next, a solution of 0.53 g of 2,2T-azobisisobutyronitrile (AIBN) dissolved in 5.34 g of ethyl acetate was added, and polymerization was initiated while maintaining the reflux temperature. After 6 hours of polymerization, the reaction was terminated by cooling, yielding a solution of acrylic copolymer (a1) with a solids content of approximately 35%. The acrylic copolymer (a1) had a number-average molecular weight of 15,000, a weight-average molecular weight of 28,000, a glass transition temperature of 88°C, and a hydroxyl value of 129 mgKOH / g.

[0075] <Synthesis Example (b1): Silsesquioxane Compound (b1)> A silsesquioxane compound represented by formula (b1) (hereinafter referred to as compound (b1)) was produced by the following method. Under a nitrogen blanket, 300 g of a compound represented by formula (α) (hereinafter referred to as compound (α)) synthesized by the method disclosed in International Publication No. 2004 / 024741 and 420 g of dehydrated toluene (Kanto Chemical Co., Ltd.) were charged into a reaction vessel, heated to 90°C, and stirred. 0.3 mL of PT-VTSC-3.0X (Umicore Japan) was added, and 69.6 g of allyl alcohol (Tokyo Chemical Industry Co., Ltd.) was added dropwise. The reaction solution was then refluxed for 5 hours, and the peak at 2140 cm was measured using a Fourier transform infrared spectrophotometer (FT-IR). -1After confirming that the peak had disappeared, heating was stopped and the mixture was cooled to room temperature. Then, 15 g of activated carbon (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reaction solution, which was stirred overnight. The activated carbon was then filtered off using Celite. The filtrate was concentrated in an evaporator until the solid concentration reached approximately 80%, and 750 g of heptane (manufactured by Wako Pure Chemical Industries, Ltd.) was added while stirring the solution, yielding a white precipitate. The resulting precipitate was filtered, thoroughly washed with heptane, and dried under reduced pressure to yield 310 g of compound (b1) (white solid). The hydroxyl value was 146 mg KOH / g. 1 H-NMR: (400 MHz, (CD3)2CO) δ = 7.27-7.57 (40H, Ph), 3.20-3.24 (12H, -OC H 2. O H ), 1.36 (8H, -C H 2), 0.58 (8H, -SiC H 2), 0.08 (24H, -Si(C H 3)2). MALDI-TOFMS: m / z C 68 H 92 NaO 18 Si 12 [M+Na]+, 1555.38.

[0076] TIFF0007803060000006.tif61122

[0077] TIFF0007803060000007.tif57130

[0078] <Synthesis Example (b2): Silsesquioxane Compound (b2)> Under a nitrogen blanket, a compound represented by formula (α) synthesized by the method disclosed in International Publication No. 2004 / 024741 and 420 g of dehydrated toluene (Kanto Chemical Co., Ltd.) were charged into a reaction vessel, heated to 95°C, and dissolved with stirring. 0.18 mL of PT-VTSC-3.0X (Umicore Japan) was added, and 122.4 g of ethylene glycol monoallyl ether (Tokyo Chemical Industry Co., Ltd.) was added dropwise. After confirming that the temperature had risen to 112°C, the reaction mixture was refluxed for 2 hours, and a peak at 2140 cm was observed by FT-IR.-1 After confirming that the peak had disappeared, heating was stopped and the mixture was cooled to room temperature. Activated carbon (15 g) was then added to the reaction mixture, which was stirred overnight, and the activated carbon was removed by filtration using Celite. The filtrate was concentrated in an evaporator until the solid concentration reached approximately 80%, and heptane was added while stirring the solution, followed by cooling in an ice bath to obtain a white precipitate. The resulting precipitate was filtered, thoroughly washed with heptane, and dried under reduced pressure to obtain 378.9 g of compound (b2) (white solid). The hydroxyl value was 127 mg KOH / g. 1 H-NMR: (400MHz, (CD3)2CO)δ = 7.20-7.55 (40H, Ph), 3.20-3.24 (8H, -OC H 2), 3.39 (4H,OH), 3.30(8H, -OC H 2CH2OH), 3.05(8H, -SiCH2CH2C H 2O-), 1.38 (8H, -SiCH2C H 2-), 0.56 (8H, -SiC H 2-), 0.08 (24H, -Si(C H 3)2).

[0079] TIFF0007803060000008.tif51149

[0080] [Preparation of Thermosetting Coating Composition] The coating liquids used in Examples 1 to 6 and Comparative Examples 1 and 2 were prepared as follows. Components (a) to (c) were selected as shown in Table 1, and mixed in the weight ratios shown in Table 1. Kyoei Chemical Co., Ltd.'s PMA (propylene glycol monomethyl ether acetate) was used as a diluent to dilute the coating liquid to a concentration of 20% by weight. All weight ratios shown in the table are solid masses. (a): Acrylic copolymer (a1) (b): Silsesquioxane compound (b1), silsesquioxane compound (b2) (c): Mitsui Chemicals, Inc. "Takenate D-170N (hexamethylene diisocyanate isocyanurate)" and "Stabio D-370N (pentamethylene diisocyanate isocyanurate)" (d): Dibutyltin dilaurate manufactured by Tokyo Chemical Industry Co., Ltd. (e): BYK-342 manufactured by Big Chemie Japan Co., Ltd.

[0081] [Manufacturing decorative films] The decorative films of Examples 1 to 6 and Comparative Examples 1 and 2 were prepared as follows. Each of the coating solutions described above was applied to the PMMA surface of a 300 μm-thick PMMA / PC two-layer film ("AW-10FSU" manufactured by Wavelock Advanced Technology Co., Ltd.) using a wire bar coater manufactured by RDS Webster, and then dried at 80°C for 3 minutes. The film was then aged at 50°C for 4 days to allow curing to proceed. In this way, decorative films were obtained in which a 5 μm-thick surface protective layer made of a cured product of the thermosetting coating composition was formed on one side of the PMMA / PC two-layer film.

[0082] <Evaluation of decorative films> The decorative film described above was evaluated from the following viewpoints and by the following methods, and the results are shown in Table 1.

[0083] (1) Heat moldability Tensile tests were conducted in a thermostatic chamber using a Shimadzu AGS-X tensile tester. Dumbbell-shaped test specimens (JIS-K7113 No. 2 test specimens, parallel section width 6±0.4 mm, parallel section length 33±2 mm, gauge length 25±1 mm) were cut from the resulting decorative film. The resulting dumbbell-shaped test specimens were then attached to the tensile tester with a chuck distance of 80 mm and held in a thermostatic chamber at 120°C for 3 minutes. The test was then conducted at a tensile speed of 50 mm / min, and the difference between the gauge length (L1) at which cracks occurred and the initial gauge length (25 mm) was measured. The elongation upon heating, ΔL, was calculated using the following formula. The higher the ΔL, the better the thermoformability. ΔL(%)=100×(L1-25) / 25

[0084] (2) Initial adhesion The surface protective layer of the resulting decorative film was subjected to a cross-cut test at 1 mm intervals in accordance with JIS K5600-6. The state of the grid formed by the cross-cuts was visually observed, and the state of adhesion between the surface protective layer of the decorative film and the PMMA / PC substrate was judged according to the following criteria. ◎: No peeling is observed within the grid, and the surface is well adhered to the substrate. ○: There is some peeling within the lattice, but it is less than 5%. ×: Peeling of 5% or more is observed within the lattice.

[0085] (3) Gloss retention after weathering test The surface protective layer of the resulting decorative film was subjected to a weathering test using the following accelerated weathering tester. Equipment: Suga Test Instruments Co., Ltd. Super Xenon Weather Meter SX-75Z Irradiance on sample surface: 180W / m 2 Continuous irradiation Test conditions: Black panel temperature 63°C ± 3°C, relative humidity 50 ± 5%, 18 minutes of water spray, 102 minutes without water spray (1 cycle), total 2500 hours (1250 cycles) (accumulated light intensity equivalent to approximately 5 years of outdoor exposure) The gloss value of the surface protective layer before and after the above test was measured at an incident / reflection angle of 60 degrees using a VG-7000 made by Nippon Denshoku Industries Co., Ltd., and the gloss retention was calculated using the following formula. The closer the gloss retention rate is to 100%, the better the weather resistance. Gloss retention rate (%) = 100 x gloss value after weathering test / gloss value before weathering test

[0086] (4) Adhesion after weathering test After conducting a weather resistance test similar to that described in (3) above, the surface protective layer was subjected to a cross-cut test at 1 mm intervals in accordance with JIS K5600-6. The state of the grid formed by the cross-cuts was visually observed, and the state of adhesion between the surface protective layer of the decorative film and the PMMA / PC substrate was judged according to the following criteria. ◎: No peeling is observed within the grid, and the surface is well adhered to the substrate. ○: There is some peeling within the lattice, but it is less than 5%. ×: Peeling of 5% or more is observed within the lattice.

[0087] (5) Chemical resistance One drop each of a 10% wt% aqueous solution of sulfuric acid, a 5% wt% aqueous solution of sodium hydroxide, a 50% wt% aqueous solution of ethanol, and toluene was added to the surface protective layer of the resulting decorative film, and the film was left at 23°C for 24 hours. After leaving the film, the surface protective layer was washed with water. The appearance was then visually inspected and rated according to the following criteria. 〇: No change on the coating surface ×: Changes in appearance such as marks or whitening can be observed on the coating surface.

[0088] Table 1. Evaluation results of decorative films made from each coating composition TIFF0007803060000009.tif81170

[0089] As shown in the table, Examples 1 to 6 have a surface protective layer that is a cured product made from a (meth)acrylic copolymer, a silsesquioxane compound having a specified structure, and a curing agent having an isocyanate group, and therefore have excellent heat moldability and excellent gloss retention and adhesion after weathering tests.

[0090] On the other hand, Comparative Examples 1 and 2 do not contain a silsesquioxane compound with a specified structure, and therefore although the initial adhesion is good, the adhesion after the weathering test is poor.

[0091] As described above, the present invention has made it possible to obtain a resin composition and a laminate thereof which are excellent in moldability, chemical resistance, weather resistance and adhesion to substrates and which can be suitably used outdoors. [Industrial Applicability]

[0092] The thermosetting coating composition of the present invention has a good balance of chemical resistance, moldability, weather resistance, and adhesion. Such a thermosetting coating composition of the present invention is useful as a surface protective layer for automotive exterior parts that require high functionality and design, such as emblems, radiator grilles, and various garnishes. It is expected that the present invention will enable the production of automotive exterior parts that can withstand the increasingly sophisticated requirements of recent years. [Explanation of symbols]

[0093] 1: Surface protective layer 2: Base material layer 3: Decorative film

Claims

1. A thermosetting coating composition comprising the following components (a) to (c): (a) A (meth)acrylic copolymer having a hydroxyl group, the hydroxyl value of which is 50 to 200 mgKOH / g and the glass transition temperature of which is 50°C or higher. (b) A silsesquioxane compound represented by formula (1) In formula (1), R is an alkylene having 1 to 10 carbon atoms and at least one -CH2 - may be replaced by -O-. (c) a curing agent having two or more isocyanate groups

2. Component (c) is an aliphatic isocyanate or an alicyclic isocyanate.

1. The thermosetting coating composition according to claim 1.

3. 3. The thermosetting coating composition according to claim 1, wherein the component (c) is an isocyanate having an isocyanuric skeleton.

4. In the thermosetting coating composition, the weight ratio of the component (a) to the component (b) The thermosetting coating according to any one of claims 1 to 3, wherein the ratio of the hydroxyl group to the hydroxyl group is 95:5 to 50:

50. Composition.

5. In the thermosetting coating composition, the total amount of the component (a) and the component (b) is the amount of isocyanate groups in the component (c) is 0.5 to 1.5 molar equivalents relative to the amount of hydroxyl groups; The thermosetting coating composition of any one of claims 1 to 4.

6. A surface protection comprising the thermosetting coating composition according to any one of claims 1 to 5. An article comprising a layer.

7. A cured product of the thermosetting coating composition according to any one of claims 1 to 5. A laminated film having a surface protective layer and a substrate layer.

8. A decorative film using the laminated film according to claim 7.

Images