Coating composition and in-mold coating method

Abstract

A purpose of the present disclosure is to provide a coating composition which can form coating films excellent in terms of adhesiveness to polycarbonate resin bases, releasability from molds, and smoothness and which has a low VOC content.　The coating composition comprises (A) hydroxylated compounds, (B) a polyisocyanate compound, and (C) a curing catalyst and has a solid concentration of 90 mass% or higher. The hydroxylated compounds (A) include a hydroxylated compound (A1) having a nurate ring structure. The coating composition has a content of the hydroxylated compound (A1) having a nurate ring structure within the range of 5-50 mass% based on the total amount of the solid components of the hydroxylated compounds (A).

Description

Coating composition and in-mold coating method

[0001] The present disclosure relates to coating compositions and in-mold coating methods.

[0002] Conventionally, for the purpose of imparting excellent appearance, performance, etc. to a substrate surface, a coating film has been formed by applying a coating composition to the substrate surface and curing the formed wet coating film. In recent years, from the viewpoint of reducing the environmental load, there has been a demand for reducing volatile organic compounds (VOCs) in coating compositions and reducing the air conditioning energy required during painting.

[0003] Generally, an automobile body is made of a metal material and a bumper is made of a resin material. In recent years, due to improvements in the strength of resin materials, there has been a shift from metal materials to lighter resin materials in areas where metal materials were previously used. In particular, the use of polycarbonate resin materials, which have excellent weather resistance, is being considered.

[0004] There are various methods for coating resin materials, one of which is in-mold coating. In-mold coating is a coating method in which a resin material is molded in a mold, a coating material is injected between the molded product and the inner wall of the mold, the coating material is cured, and then the molded product coated with the coating film is removed from the mold. This coating method is carried out in a closed system from coating to curing. This coating method requires that the coating be substantially solvent-free to avoid defects in the coating film such as air bubbles.

[0005] In the in-mold coating, high adhesion between the coating film and the resin material as well as mold releasability of the coating film from the mold are required. Patent Document 1 discloses a two-component coating material composition containing a coating base component A and a curing component B, wherein the coating base component A comprises: i. one or more polyols A1 selected from the group of polyols containing ester groups, and having a hydroxyl value of 300 to 500 mg KOH / g and a hydroxyl group functionality of more than 2; ii. a polyol having a general formula (I): R 1 that does not contain an ether group or an ester group; １ -(OH) ｐ (In the formula, R １is a p-valent branched, cyclic or straight-chain, saturated or unsaturated aliphatic hydrocarbon radical having 5 to 18 carbon atoms, and the radical R １ optionally containing one or more tertiary amino groups, and p is 2 to 6), iii. one or more aliphatic polyols A2 of the general formula (II): R ２ -(C=O) ｒ -O-(AO) ｓ -R ３ (In the formula, R ２ is a saturated or unsaturated aliphatic hydrocarbon radical having 6 to 30 carbon atoms, R ３ is H, radical PO(OH) ２or a radical of an optionally partially phosphorylated mono- or disaccharide or a radical of an optionally partially phosphorylated alditol, where AO represents one or more alkylene oxide radicals selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, r is 0 or 1, and s is 0 to 30), iv. one or more crosslinking catalysts A4 selected from the group of organotin compounds, v. one or more polyamines A5 having at least two secondary amino groups and an amine value of 120 to 280 mg KOH / g, and ix. one or more additives A9 selected from the group consisting of wetting agents and / or dispersants, rheological aids, and flow control agents, and wherein said curing component B comprises: i. Disclosed is a two-component coating material composition comprising one or more polyisocyanates B1 having an average of 2.4 to 5 NCO groups, the two-component coating material composition comprising a solids content of at least 96% by weight according to ASTM D2369 (2015), based on the total weight of the two-component coating material composition, and characterized in that the molar ratio of NCO groups in the curing component B to acidic hydrogen atoms of hydroxyl groups, primary amino groups, and secondary amino groups in the paint base component A is 1:1.15 to 1:0.95. The two-component coating material composition is disclosed as allowing damage-free release from normally metal mold surfaces without the use of external mold release agents, while ensuring excellent adhesion to the substrate, and being recoatable with further coating films, such as base coats and clear coats, to form surfaces of excellent quality without costly and inconvenient cleaning and / or polishing steps.

[0006] Special Publication 2020-528103

[0007] The technology described in Patent Document 1 results in a low VOC content in the resulting coating composition and excellent mold releasability for the formed coating film, but the resulting coating film sometimes lacks sufficient adhesion to polycarbonate resin substrates.The present disclosure aims to provide a coating composition with a low VOC content that is capable of forming a coating film that has excellent adhesion to polycarbonate resin substrates, mold releasability, and smoothness.

[0008] As a result of extensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned object can be achieved by a coating composition comprising a hydroxyl group-containing compound (A), a polyisocyanate compound (B), and a curing catalyst (C) and having a solids concentration of 90 mass % or more, wherein the hydroxyl group-containing compound (A) comprises a hydroxyl group-containing compound (A1) having a nurate ring structure.

[0009] That is, the present disclosure relates to the following items <1> to <10>. <1> A coating composition comprising (A) a hydroxyl group-containing compound, (B) a polyisocyanate compound, and (C) a curing catalyst, and having a solids concentration of 90% by mass or more, wherein the hydroxyl group-containing compound (A) comprises a hydroxyl group-containing compound (A1) having a nurate ring structure. <2> The coating composition according to <1>, wherein the content of the hydroxyl group-containing compound (A1) having a nurate ring structure is within the range of 5 to 50% by mass, based on the total solids content of the hydroxyl group-containing compound (A). <3> The coating composition according to <1> or <2>, wherein the hydroxyl group-containing compound (A) comprises a hydroxyl group-containing acrylic resin (A2). <4> The coating composition according to any one of <1> to <3>, wherein the hydroxyl group-containing compound (A) comprises a polycaprolactone resin (A3') having three or more hydroxyl groups per molecule. <5> The coating composition according to any one of <1> to <4>, wherein the content of the curing catalyst (C) is within the range of 0.1 to 2.0 mass% based on the total amount of the coating composition. <6> The coating composition according to any one of <1> to <5>, further comprising a dehydrating agent (D). <7> The coating composition according to any one of <1> to <5>, wherein (i) the coating composition is applied to a polycarbonate resin substrate so that the film thickness after drying is 200 μm to form an uncured coating film, (ii) the uncured coating film is heat-cured at 80°C for 1 minute to form a cured coating film, and (iii) when the Martens hardness of the cured coating film is measured by indenting a square pyramidal diamond indenter into the cured coating film over 20 seconds at a temperature of 23°C and a humidity of 50% RH under conditions of a maximum test load of 20 mN, the Martens hardness is 60 to 150 N / mm ２The coating composition according to any one of <1> to <6>, which is configured to have a Martens hardness within the range of 0.05 to 0.05. <8> The coating composition according to any one of <1> to <7>, which is an in-mold coating coating composition. <9> The coating composition according to <8>, which further comprises an internal release agent (E). <10> The coating composition according to <9>, which internal release agent (E) comprises a fatty acid amide. <11> An in-mold coating method, which comprises the steps of injecting an in-mold coating coating composition between a molded substrate and an inner wall of a mold, curing the in-mold coating coating composition, and then removing the coated molded article from the mold, wherein the in-mold coating coating composition is the coating composition according to any one of <1> to <10>. <12> The in-mold coating method according to <11>, which further comprises an internal release agent (E). <13> The in-mold coating method according to <12>, which internal release agent (E) comprises a fatty acid amide.

[0010] According to the present disclosure, it is possible to provide a coating composition that is capable of forming a coating film that has excellent adhesion to polycarbonate resin substrates, mold releasability, and smoothness, and that has a low VOC content.

[0011] The present disclosure will be described in detail below, but these are merely examples of desirable embodiments, and the present disclosure is not limited to these contents. [Paint composition] The paint composition according to the present disclosure is a paint composition comprising a hydroxyl group-containing compound (A), a polyisocyanate compound (B), and a curing catalyst (C), and having a solids concentration of 90 mass % or more, wherein the hydroxyl group-containing compound (A) comprises a hydroxyl group-containing compound (A1) having a nurate ring structure.

[0012] In this specification, "solid content" refers to non-volatile components such as resins, curing agents, and pigments remaining after drying at 80°C for 30 minutes. The solid content can be determined, for example, by weighing a sample into a heat-resistant container such as an aluminum foil cup, spreading the sample on the bottom of the container, drying at 80°C for 30 minutes, and weighing the mass of the components remaining after drying. In addition, in this specification, "solid content concentration" refers to the mass ratio of the solid content in the composition. Therefore, the solid content concentration of a composition can be calculated, for example, by weighing 1.0 g of the composition into a heat-resistant container such as an aluminum foil cup, spreading the composition on the bottom of the container, drying at 80°C for 30 minutes, weighing the mass of the components remaining in the composition after drying, and determining the ratio of the mass of the components remaining after drying to the total mass of the composition before drying.

[0013] The solids concentration in the coating composition according to the present disclosure is 90% by mass or more. By having a solids concentration of the coating composition of 90% by mass or more, the VOC content in the resulting coating composition can be reduced. From the viewpoint of reducing the VOC content in the resulting coating composition, the solids concentration of the coating composition according to the present disclosure is preferably within the range of 93 to 100% by mass, more preferably within the range of 95 to 100% by mass, and even more preferably within the range of 97 to 100% by mass.

[0014] [Hydroxyl Group-Containing Compound (A)] The hydroxyl group-containing compound (A) is a compound having at least one hydroxyl group per molecule. Examples of the hydroxyl group-containing compound (A) include hydroxyl group-containing polymers such as hydroxyl group-containing compounds (A1) having a nurate ring structure, hydroxyl group-containing acrylic resins (A2), hydroxyl group-containing polycaprolactone resins (A3), hydroxyl group-containing polyester resins, hydroxyl group-containing polyether resins, hydroxyl group-containing polycarbonate resins, hydroxyl group-containing acrylic-modified polyester resins, hydroxyl group-containing polyurethane resins, hydroxyl group-containing epoxy resins, hydroxyl group-containing alkyd resins, and any combinations thereof.

[0015] The hydroxyl group-containing compound (A) according to the present disclosure includes a hydroxyl group-containing compound (A1) having a nurate ring structure. When the hydroxyl group-containing compound (A) according to the present disclosure includes a hydroxyl group-containing compound (A1) having a nurate ring structure, the adhesion of the formed coating film to a polycarbonate resin substrate can be improved.

[0016] [Hydroxyl Group-Containing Compound (A1) Having a Nurate Ring Structure] Examples of the hydroxyl group-containing compound (A1) having a nurate ring structure include tris(hydroxyalkyl)isocyanurates such as tris(hydroxyethyl)isocyanurate, tris(hydroxypropyl)isocyanurate, and tris(hydroxybutyl)isocyanurate; ε-caprolactone-modified products of the tris(hydroxyalkyl)isocyanurates; alkylene oxide-modified products of the tris(hydroxyalkyl)isocyanurates; esters of tris(hydroxyethyl)isocyanurate obtained by reacting tris(hydroxyethyl)isocyanurate, a diol compound, and a dicarboxylic acid in a state where the hydroxyl groups in the tris(hydroxyethyl)isocyanurate and the diol compound are in excess relative to the carboxyl groups in the dicarboxylic acid; reaction products obtained by reacting a polyisocyanate compound having a nurate ring structure with a diol compound in a state where the hydroxyl groups in the diol compound are in excess relative to the isocyanate groups in the polyisocyanate compound having a nurate ring structure; and any combinations thereof.

[0017] From the viewpoints of the smoothness of the coating film formed and the adhesion to the polycarbonate resin substrate, the hydroxyl group-containing compound (A1) having a nurate ring structure preferably contains an ε-caprolactone-modified tris(2-hydroxyethyl)isocyanurate.

[0018] The hydroxyl group-containing compound (A1) having a nurate ring structure preferably has a number average molecular weight of 300 or more, more preferably 400 or more, and even more preferably 450 or more, from the viewpoints of the smoothness of the coating film to be formed and the mold releasability, and preferably has a number average molecular weight of 1500 or less, more preferably 1300 or less, and even more preferably 1100 or less.

[0019] The hydroxyl value of the hydroxyl-containing compound (A1) having a nurate ring structure is preferably 50 mgKOH / g or more, more preferably 100 mgKOH / g or more, and even more preferably 150 mgKOH / g or more, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, and is preferably 600 mgKOH / g or less, more preferably 400 mgKOH / g or less, and even more preferably 300 mgKOH / g or less.

[0020] In this specification, the number average molecular weight and weight average molecular weight are values ​​obtained by converting the retention time (retention volume) measured using a gel permeation chromatograph (GPC) into the molecular weight of polystyrene using the retention time (retention volume) of a standard polystyrene of known molecular weight measured under the same conditions. Specifically, the gel permeation chromatograph uses "HLC-8120GPC" (trade name, manufactured by Tosoh Corporation), four columns ("TSKgel G4000HXL", "TSKgel G3000HXL", "TSKgel G2500HXL", and "TSKgel G2000HXL" (trade names, all manufactured by Tosoh Corporation) in total, a differential refractometer is used as the detector, and the mobile phase is tetrahydrofuran, the measurement temperature is 40°C, and the flow rate is 1 mL / min.

[0021] From the viewpoints of the smoothness of the coating film to be formed, adhesion to the polycarbonate resin substrate, releasability from the mold, etc., the content of the hydroxyl group-containing compound (A1) having a nurate ring structure is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 10% by mass or more, based on the total solid content of the hydroxyl group-containing compound (A), and is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less.

[0022] [Hydroxyl-containing acrylic resin (A2)] The hydroxyl-containing compound (A) preferably contains a hydroxyl-containing acrylic resin (A2) from the viewpoint of the mold releasability of the coating film formed. The hydroxyl-containing acrylic resin (A2) can be produced, for example, by copolymerizing a hydroxyl-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl-containing polymerizable unsaturated monomer by a method known per se, such as solution polymerization or emulsion polymerization in water, and is preferably produced by solution polymerization. However, in the present disclosure, a hydroxyl-containing acrylic resin having a nurate ring structure is not included in the hydroxyl-containing acrylic resin (A2), but is included in the hydroxyl-containing compound (A1) having a nurate ring structure.

[0023] When the hydroxyl group-containing acrylic resin (A2) is produced by solution polymerization, the solvent used in the solution polymerization preferably contains a polyhydric alcohol, from the viewpoint of reducing the VOC content in the resulting coating composition.

[0024] The hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated bonds per molecule. Examples of the hydroxyl group-containing polymerizable unsaturated monomer include monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; ε-caprolactone-modified monoesters of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms; N-hydroxymethyl (meth)acrylamide; allyl alcohol; and (meth)acrylates having a polyoxyalkylene chain with a hydroxyl group at the molecular terminal. However, in this embodiment, even if a monomer corresponding to the polymerizable unsaturated monomer having an ultraviolet absorbing functional group (xvii) described later has a hydroxyl group, it should be defined as another polymerizable unsaturated monomer copolymerizable with the above-mentioned hydroxyl group-containing polymerizable unsaturated monomer, and is excluded from the hydroxyl group-containing polymerizable unsaturated monomer. These can be used alone or in combination of two or more kinds.

[0025] Examples of other polymerizable unsaturated monomers copolymerizable with the above hydroxyl group-containing polymerizable unsaturated monomer include the following monomers (i) to (xx) and any combinations thereof. (i) Alkyl or cycloalkyl (meth)acrylates: for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, tricyclodecanyl (meth)acrylate, etc.

[0026] (ii) Polymerizable unsaturated monomers having an isobornyl group: isobornyl (meth)acrylate, etc. (iii) Polymerizable unsaturated monomers having an adamantyl group: adamantyl (meth)acrylate, etc. (iv) Polymerizable unsaturated monomers having a tricyclodecenyl group: tricyclodecenyl (meth)acrylate, etc. (v) Polymerizable unsaturated monomers containing an aromatic ring: benzyl (meth)acrylate, styrene, α-methylstyrene, vinyltoluene, etc.

[0027] (vi) Polymerizable unsaturated monomers having an alkoxysilyl group: vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, etc. (vii) Polymerizable unsaturated monomers having a fluorinated alkyl group: perfluoroalkyl(meth)acrylates such as perfluorobutylethyl(meth)acrylate and perfluorooctylethyl(meth)acrylate; fluoroolefins, etc. (viii) Polymerizable unsaturated monomers having a photopolymerizable functional group such as a maleimide group

[0028] (ix) vinyl compounds: N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate, etc. (x) carboxyl group-containing polymerizable unsaturated monomers: (meth)acrylic acid, maleic acid, crotonic acid, β-carboxyethyl (meth)acrylate, etc. (xi) nitrogen-containing polymerizable unsaturated monomers: (meth)acrylonitrile, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylamide, methylenebis(meth)acrylamide, ethylenebis(meth)acrylamide, adducts of glycidyl (meth)acrylate and amine compounds, etc.

[0029] (xii) Polymerizable unsaturated monomers having two or more polymerizable unsaturated groups in one molecule: allyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, etc. (xiii) Epoxy group-containing polymerizable unsaturated monomers: glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexylpropyl (meth)acrylate, allyl glycidyl ether, etc. (xiv) (meth)acrylates having a polyoxyethylene chain with an alkoxy group at the molecular terminal

[0030] (xv) Polymerizable unsaturated monomers having a sulfonic acid group: 2-acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl (meth)acrylate, allylsulfonic acid, 4-styrenesulfonic acid, etc.; sodium salts and ammonium salts of these sulfonic acids, etc. (xvi) Polymerizable unsaturated monomers having a phosphoric acid group: acid phosphooxyethyl (meth)acrylate, acid phosphooxypropyl (meth)acrylate, acid phosphooxypoly(oxyethylene)glycol (meth)acrylate, acid phosphooxypoly(oxypropylene)glycol (meth)acrylate, etc. (xvii) Polymerizable unsaturated monomers having an ultraviolet absorbing functional group: 2-hydroxy-4(3-methacryloyloxy-2-hydroxypropoxy)benzophenone, 2-hydroxy-4-(3-acryloyloxy-2-hydroxypropoxy)benzophenone, 2,2'-dihydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone, 2,2'-dihydroxy-4-(3-acryloyloxy-2-hydroxypropoxy)benzophenone, 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole, etc.

[0031] (xviii) Light-stable polymerizable unsaturated monomers: 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, etc. (xix) (xx) Polymerizable unsaturated monomers having a carbonyl group: acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone), etc. (xx) Polymerizable unsaturated monomers having an acid anhydride group: maleic anhydride, itaconic anhydride, citraconic anhydride, etc.

[0032] As used herein, the term "polymerizable unsaturated group" refers to an unsaturated group capable of radical polymerization. Examples of such polymerizable unsaturated groups include vinyl groups, (meth)acryloyl groups, (meth)acrylamide groups, vinyl ether groups, allyl groups, propenyl groups, isopropenyl groups, and maleimide groups. Furthermore, as used herein, "(meth)acrylate" refers to acrylate and / or methacrylate. "(meth)acrylic acid" refers to acrylic acid and / or methacrylic acid. Furthermore, "(meth)acryloyl" refers to acryloyl and / or methacryloyl. Furthermore, "(meth)acrylamide" refers to acrylamide and / or methacrylamide.

[0033] The number average molecular weight of the hydroxyl group-containing acrylic resin (A2) is preferably 800 or more, more preferably 1000 or more, and even more preferably 1200 or more, from the viewpoints of the smoothness of the coating film to be formed and the releasability from the mold, and is preferably 3000 or less, more preferably 2500 or less, and even more preferably 2200 or less.

[0034] From the viewpoint of the mold releasability of the coating film to be formed, the hydroxyl value of the hydroxyl-containing acrylic resin (A2) is preferably 50 mgKOH / g or more, more preferably 70 mgKOH / g or more, even more preferably 100 mgKOH / g or more, and is preferably 250 mgKOH / g or less, more preferably 230 mgKOH / g or less, even more preferably 210 mgKOH / g or less.

[0035] The glass transition temperature (Tg) of the hydroxyl group-containing acrylic resin (A2) is preferably −20° C. or higher, more preferably −10° C. or higher, even more preferably 0° C. or higher, and is preferably 70° C. or lower, more preferably 60° C. or lower, even more preferably 50° C. or lower, from the viewpoints of reducing the VOC content in the resulting coating composition and improving the adhesion of the coating film to the polycarbonate resin substrate and the mold releasability.

[0036] In this specification, the glass transition temperature (Tg) of the hydroxyl group-containing acrylic resin (A2) is a value calculated by the following formula: 1 / Tg(K)=W1 / T1+W2 / T2+...Wn / Tn Tg(°C)=Tg(K)-273 In the formula, W1, W2,...Wn are the mass fractions of each monomer, and T1, T2,...Tn are the glass transition temperatures Tg(K) of the homopolymers of each monomer. The glass transition temperatures of the homopolymers of each monomer are calculated by the ... The glass transition temperature of a monomer not described in the document is the static glass transition temperature when a homopolymer of the monomer is synthesized so as to have a weight-average molecular weight of about 50,000.

[0037] The polyhydric alcohol that can be used as a solvent when producing the hydroxyl group-containing acrylic resin (A2) by solution polymerization is a compound having two or more hydroxyl groups per molecule. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, tetramethylene glycol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, hydrochloride polylactone diols obtained by adding a lactone compound such as ε-caprolactone to any of these dihydric alcohols; ester diol compounds such as bis(hydroxyethyl) terephthalate; polyether diol compounds such as alkylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; trihydric or higher alcohols such as glycerin, trimethylolethane, trimethylolpropane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, and mannite; polylactone polyol compounds obtained by adding a lactone compound such as ε-caprolactone to any of these trihydric or higher alcohols; fatty acid esters of glycerin; and any combination thereof.

[0038] From the viewpoint of reducing the VOC content in the resulting coating composition, the amount of the polyhydric alcohol added is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, based on the total amount of the hydroxyl group-containing acrylic resin (A2), and is preferably 150% by mass or less, more preferably 130% by mass or less, and even more preferably 100% by mass or less.

[0039] The solvent used in the solution polymerization method may contain an organic solvent other than the polyhydric alcohol, as necessary. Examples of the organic solvent include aromatic solvents such as toluene, xylene, and "Swasol 1000" (trade name, high-boiling point petroleum solvent, manufactured by Cosmo Oil Co., Ltd.); ester solvents such as ethyl acetate, butyl acetate, propyl propionate, butyl propionate, 1-methoxy-2-propyl acetate, 2-ethoxyethyl propionate, 3-methoxybutyl acetate, ethylene glycol ethyl ether acetate, and propylene glycol methyl ether acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone; and alcohol solvents such as isopropanol, n-butanol, isobutanol, and 2-ethylhexanol.

[0040] When the hydroxyl group-containing compound (A) contains the hydroxyl group-containing acrylic resin (A2), the content of the hydroxyl group-containing acrylic resin (A2) is, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate, releasability from the mold, smoothness, etc., preferably 35% by mass or more, more preferably 37% by mass or more, even more preferably 40% by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, based on the total solid content of the hydroxyl group-containing compound (A).

[0041] [Hydroxyl Group-Containing Polycaprolactone Resin (A3)] From the viewpoint of the smoothness of the coating film to be formed, the hydroxyl group-containing compound (A) preferably contains a hydroxyl group-containing polycaprolactone resin (A3). The hydroxyl group-containing polycaprolactone resin (A3) can be obtained, for example, by ring-opening polymerization of ε-caprolactone using a dihydric to tetrahydric polyhydric alcohol as an initiator. Examples of the dihydric or higher polyhydric alcohol include ethylene glycol, glycerin, trimethylolethane, trimethylolpropane, diglycerin, ditrimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, polyhydric alcohol compounds obtained by reacting dimethylolalkanoic acid with a monoepoxy compound (e.g., "Cardura E10P; glycidyl ester of synthetic highly branched saturated fatty acid" manufactured by HEXION Specialty Chemicals), and any combination thereof.

[0042] However, in the present disclosure, a hydroxyl-containing compound obtainable by ring-opening polymerization of ε-caprolactone using a polyhydric alcohol having a nurate ring structure as an initiator is not included in the hydroxyl-containing polycaprolactone resin (A3), but is included in the hydroxyl-containing compound having a nurate ring structure (A1). Also, in the present disclosure, a resin modified by adding ε-caprolactone to a hydroxyl-containing acrylic resin is not included in the hydroxyl-containing polycaprolactone resin (A3), but is included in the hydroxyl-containing acrylic resin (A2).

[0043] The hydroxyl group-containing polycaprolactone resin (A3) may be a commercially available product, such as "PLACCEL 205," "PLACCEL 205H," "PLACCEL L205AL," "PLACCEL 205U," "PLACCEL 208," "PLACCEL 210," "PLACCEL 210N," "PLACCEL 210CP," "PLACCEL 212," "PLACCEL L212AL," "PLACCEL 220," "PLACCEL 220N," "PLACCEL 220CPB," "PLACCEL 220CPT," and "PLACCEL 2 20UA," "Placcel 220NP1," "Placcel L220AL," "Placcel 220EB," "Placcel 230," "Placcel 230N," "Placcel 240," "Placcel 303," "Placcel 305," "Placcel 308," "Placcel 309," "Placcel 312," "Placcel 320," "Placcel L320AL," "Placcel 410" (all trade names, manufactured by Daicel Corporation), "TONE Examples of the acrylic acid esters include Capa 0201, Capa 0230, Capa 0249, Capa 0301, Capa 0305, Capa 0310, Capa 1241, Capa 1278, and Capa 2221 (all trade names manufactured by The Dow Chemical Company), Capa 2043, Capa 2101, Capa 2201, Capa 2205, Capa 2209, Capa 2201A, Capa 2203A, Capa 3031, Capa 3050J, Capa 3091, and Capa 4101 (all trade names manufactured by Ingevity).

[0044] The hydroxyl group-containing polycaprolactone resin (A3) preferably contains a hydroxyl group-containing polycaprolactone resin (A3') having three or more hydroxyl groups per molecule, from the viewpoints of smoothness of the coating film to be formed, releasability from a mold, etc. As the hydroxyl group-containing polycaprolactone resin (A3') having three or more hydroxyl groups per molecule, commercially available products can be used. Examples of commercially available products include "PLACCEL 303," "PLACCEL 305," "PLACCEL 308," "PLACCEL 309," "PLACCEL 312," "PLACCEL 320," "PLACCEL L320AL," and "PLACCEL 410" (all trade names, manufactured by Daicel Corporation), "TONE 0301," "TONE 0305," and "TONE 0310" (all trade names, manufactured by The Dow Chemical Company), and "Capa 3031," "Capa 3050J," "Capa 3091," and "Capa 4101" (all trade names, manufactured by Ingevity).

[0045] The number average molecular weight of the hydroxyl group-containing polycaprolactone resin (A3) is preferably 280 or more, more preferably 290 or more, even more preferably 300 or more, from the viewpoints of reducing the VOC content in the resulting coating composition and improving the smoothness of the coating film formed, and is preferably 1,000 or less, more preferably 850 or less, even more preferably 600 or less.

[0046] From the viewpoint of the mold releasability of the coating film to be formed, the hydroxyl value of the hydroxyl-containing polycaprolactone resin (A3) is preferably 50 mgKOH / g or more, more preferably 100 mgKOH / g or more, even more preferably 130 mgKOH / g or more, and is preferably 900 mgKOH / g or less, more preferably 750 mgKOH / g or less, even more preferably 600 mgKOH / g or less.

[0047] When the hydroxyl group-containing compound (A) contains the hydroxyl group-containing polycaprolactone resin (A3), the content of the hydroxyl group-containing polycaprolactone resin (A3) is, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate, releasability from the mold, smoothness, etc., preferably 4 mass % or more, more preferably 10 mass % or more, even more preferably 15 mass % or more, and is preferably 45 mass % or less, more preferably 40 mass % or less, even more preferably 35 mass % or less, based on the total solids content of the hydroxyl group-containing compound (A).

[0048] The hydroxyl-containing polyester resin can be typically produced by an esterification reaction or transesterification reaction between an acid component and an alcohol component. The acid component can be a compound typically used as a polycarboxylic acid in the production of the hydroxyl-containing polyester resin. Examples of such polycarboxylic acids include aliphatic polybasic acids, alicyclic polybasic acids, and aromatic polybasic acids.

[0049] The alicyclic polybasic acids are generally compounds having one or more alicyclic structures and two or more carboxyl groups per molecule, acid anhydrides of such compounds, and esterified products of such compounds. The alicyclic structures can be primarily 4- to 6-membered ring structures. Examples of the alicyclic polybasic acids include alicyclic polycarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, 3-methyl-1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, and 1,3,5-cyclohexanetricarboxylic acid; anhydrides of such alicyclic polycarboxylic acids; esterified products of such alicyclic polycarboxylic acids with lower alkyl groups having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, and any combination thereof.

[0050] The aliphatic polybasic acid is generally an aliphatic compound having two or more carboxyl groups per molecule, an acid anhydride of the aliphatic compound, or an ester of the aliphatic compound. Examples of the aliphatic polybasic acid include aliphatic polycarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, octadecanedioic acid, citric acid, and butanetetracarboxylic acid; anhydrides of the aliphatic polycarboxylic acids; esters of the aliphatic polycarboxylic acids with lower alkyl groups having 1 to 6, preferably 1 to 4, carbon atoms; and any combinations thereof.

[0051] The aromatic polybasic acid is generally an aromatic compound having two or more carboxyl groups per molecule, an acid anhydride of the aromatic compound, or an ester of the aromatic compound. Examples of the aromatic polybasic acid include aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, trimellitic acid, and pyromellitic acid; anhydrides of the aromatic polycarboxylic acids; lower alkyl esters of the aromatic polycarboxylic acids having 1 to 6, preferably 1 to 4, carbon atoms; and any combinations thereof.

[0052] Acid components other than the above-mentioned aliphatic polybasic acids, alicyclic polybasic acids, and aromatic polybasic acids can also be used. Such acid components are not particularly limited, and examples thereof include fatty acids such as coconut oil fatty acids, cottonseed oil fatty acids, hempseed oil fatty acids, rice bran oil fatty acids, fish oil fatty acids, tall oil fatty acids, soybean oil fatty acids, linseed oil fatty acids, tung oil fatty acids, rapeseed oil fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids, and safflower oil fatty acids; monocarboxylic acids such as isononanoic acid, neodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexanoic acid, and 10-phenyloctadecanoic acid; hydroxycarboxylic acids such as lactic acid, 3-hydroxybutanoic acid, and 3-hydroxy-4-ethoxybenzoic acid; and any combinations thereof.

[0053] As the alcohol component, a polyhydric alcohol having two or more hydroxyl groups in one molecule can be suitably used, such as ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,2-pentanediol. 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylene glycol, tetramethylene glycol, 3-methyl-4,3-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, tetramethylene glycol Examples of the polyol include dihydric alcohols such as cyclodecane dimethanol, hydroxypivalic acid neopentyl glycol ester, hydrogenated bisphenol A, hydrogenated bisphenol F, and dimethylolpropionic acid; polylactone diols obtained by adding a lactone compound such as ε-caprolactone to these dihydric alcohols; ester diol compounds such as bis(hydroxyethyl) terephthalate; polyether diol compounds such as alkylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; trihydric or higher alcohols such as glycerin, trimethylolethane, trimethylolpropane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, and mannite; polylactone polyol compounds obtained by adding a lactone compound such as ε-caprolactone to these trihydric or higher alcohols; fatty acid esters of glycerin; and any combination thereof.

[0054] Alcohol components other than the above polyhydric alcohols can also be used. Examples of such alcohol components include, but are not limited to, monoalcohols such as methanol, ethanol, propyl alcohol, butyl alcohol, isobutyl alcohol, pentyl alcohol, 2-ethylhexyl alcohol, stearyl alcohol, benzyl alcohol, phenethyl alcohol, and 2-phenoxyethanol; alcohol compounds obtained by reacting a monoepoxy compound such as propylene oxide, butylene oxide, or "Cardura E10P" (trade name, manufactured by Hexion, a glycidyl ester of a synthetic highly branched saturated fatty acid) with an acid; and any combination thereof.

[0055] The method for producing the hydroxyl group-containing polyester resin is not particularly limited and can be carried out according to a conventional method. For example, the hydroxyl group-containing polyester polyol resin can be produced by heating the acid component and the alcohol component in a nitrogen stream at about 150 to 250°C for about 5 to 10 hours to cause an esterification reaction or transesterification reaction between the acid component and the alcohol component.

[0056] When the acid component and the alcohol component are subjected to an esterification reaction or transesterification reaction, these components may be added to a reaction vessel all at once, or one or both may be added in several portions. Alternatively, the hydroxyl-containing polyester resin may be first synthesized, and then the resulting hydroxyl-containing polyester resin may be reacted with an acid anhydride to half-esterify it into a carboxyl- and hydroxyl-containing polyester resin. Alternatively, the carboxyl-containing polyester resin may be first synthesized, and then the alcohol component may be added to produce the hydroxyl-containing polyester resin.

[0057] In the above-mentioned esterification or transesterification reaction, a catalyst known per se, such as dibutyltin oxide, antimony trioxide, zinc acetate, manganese acetate, cobalt acetate, calcium acetate, lead acetate, tetrabutyl titanate, or tetraisopropyl titanate, can be used as a catalyst for promoting the reaction.

[0058] The hydroxyl group-containing polyester resin can be modified with a fatty acid, a monoepoxy compound, a polyisocyanate compound, or the like during or after production of the resin. Examples of the fatty acid include coconut oil fatty acid, cottonseed oil fatty acid, hempseed oil fatty acid, rice bran oil fatty acid, fish oil fatty acid, tall oil fatty acid, soybean oil fatty acid, linseed oil fatty acid, tung oil fatty acid, rapeseed oil fatty acid, castor oil fatty acid, dehydrated castor oil fatty acid, and safflower oil fatty acid. Examples of the monoepoxy compound include "Cardura E10P" (trade name, manufactured by Hexion, a glycidyl ester of a synthetic highly branched saturated fatty acid).

[0059] Examples of the polyisocyanate compound include aliphatic diisocyanate compounds such as lysine diisocyanate, hexamethylene diisocyanate, and trimethylhexane diisocyanate; alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-(isocyanatomethyl)cyclohexane, and 1,4-(isocyanatomethyl)cyclohexane; aromatic diisocyanate compounds such as methylisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, and diphenylmethane diisocyanate; organic polyisocyanates themselves, such as trivalent or higher polyisocyanates such as lysine triisocyanate and 4-(isocyanatomethyl)octamethylene diisocyanate; adducts of these organic polyisocyanates with polyhydric alcohols, low-molecular-weight polyester resins, water, and the like; cyclized polymers of these organic polyisocyanates (for example, isocyanurates), biuret-type adducts, and any combinations thereof.

[0060] The number average molecular weight of the hydroxyl group-containing polyester resin is preferably 300 or more, more preferably 400 or more, and even more preferably 450 or more, from the viewpoints of reducing the VOC content in the resulting coating composition and improving the mold releasability of the coating film formed, and is preferably 1000 or less, more preferably 850 or less, and even more preferably 600 or less.

[0061] From the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, the hydroxyl value of the hydroxyl-containing polyester resin is preferably 20 mgKOH / g or more, more preferably 100 mgKOH / g or more, and even more preferably 300 mgKOH / g or more, and is preferably 600 mgKOH / g or less, more preferably 580 mgKOH / g or less, and even more preferably 560 mgKOH / g or less.

[0062] The glass transition temperature (Tg) of the hydroxyl group-containing polyester resin is preferably −80° C. or higher, more preferably −70° C. or higher, and even more preferably −60° C. or higher, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, and is preferably 10° C. or lower, more preferably 5° C. or lower, and even more preferably 0° C. or lower.

[0063] The glass transition temperature can be measured, for example, using a differential scanning calorimeter "DSC-50Q" (trade name, manufactured by Shimadzu Corporation), by placing a sample in a measuring cup, vacuum suctioning to completely remove the solvent, and then measuring the change in calorific value in the range of -100°C to 150°C at a temperature increase rate of 3°C / min, and defining the first change point in the baseline on the low temperature side as the static glass transition temperature.

[0064] When the hydroxyl group-containing compound (A) contains a hydroxyl group-containing polyester resin, the content of the hydroxyl group-containing polyester resin is, from the viewpoints of reducing the VOC content in the resulting coating composition and improving the adhesion of the coating film to the polycarbonate resin substrate and the mold releasability, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 95% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, based on the total solid content of the hydroxyl group-containing compound (A).

[0065] Examples of the hydroxyl group-containing polyether resin include alkylene oxide adducts of hydroxyl group-containing monomers, ring-opening (co)polymers of alkylene oxides or cyclic ethers (such as tetrahydrofuran), etc. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene glycol-propylene glycol (block or random) copolymers, polyhexamethylene glycol, polyoctamethylene glycol, and any combinations thereof.

[0066] The number average molecular weight of the hydroxyl group-containing polyether resin is preferably 300 or more, more preferably 350 or more, even more preferably 400 or more, from the viewpoints of reducing the VOC content in the resulting coating composition, and improving the adhesion of the coating film to the polycarbonate resin substrate and the mold releasability, and is preferably 1000 or less, more preferably 850 or less, even more preferably 600 or less.

[0067] From the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, the hydroxyl value of the hydroxyl-containing polyether resin is preferably 50 mgKOH / g or more, more preferably 70 mgKOH / g or more, and even more preferably 90 mgKOH / g or more, and is preferably 600 mgKOH / g or less, more preferably 500 mgKOH / g or less, and even more preferably 400 mgKOH / g or less.

[0068] When the hydroxyl group-containing compound (A) contains a hydroxyl group-containing polyether resin, the content of the hydroxyl group-containing polyether resin is preferably 5 mass % or more, more preferably 10 mass % or more, based on the total solid content of the hydroxyl group-containing compound (A), from the viewpoints of reducing the VOC content in the resulting coating composition and improving the adhesion of the coating film formed to the polycarbonate resin substrate, and is preferably 95 mass % or less, more preferably 50 mass % or less, and even more preferably 25 mass % or less.

[0069] The hydroxyl group-containing polycarbonate resin is a compound obtained by a conventional polycondensation reaction of a known polyol component with a carbonylating agent. Examples of the polyol component include a diol component and a polyhydric alcohol component such as a trihydric or higher alcohol.

[0070] Examples of the diol component include linear diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol; 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl- Examples of the diol include branched diols such as 1,3-pentanediol and 2-ethyl-1,3-hexanediol; alicyclic diols such as 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol; aromatic diols such as p-xylenediol and p-tetrachloroxylenediol; ether-based diols such as diethylene glycol and dipropylene glycol; polylactone diols obtained by adding a lactone compound such as ε-caprolactone to any of these diol components; and any combination thereof.

[0071] Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, a dimer of trimethylolpropane, and pentaerythritol; polylactone polyols obtained by adding a lactone compound such as ε-caprolactone to any of these trihydric or higher alcohols; and any combinations thereof.

[0072] As the carbonylating agent, known agents can be used. Specific examples include alkylene carbonate, dialkyl carbonate, diallyl carbonate, phosgene, and any combination thereof. Among these, preferred examples include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and diphenyl carbonate.

[0073] The number average molecular weight of the hydroxyl group-containing polycarbonate resin is preferably 300 or more, more preferably 400 or more, even more preferably 450 or more, from the viewpoints of reducing the VOC content in the resulting coating composition, and improving the adhesion of the coating film to the polycarbonate resin substrate and the releasability from the mold, and is preferably 2000 or less, more preferably 1000 or less, even more preferably 900 or less.

[0074] The hydroxyl value of the hydroxyl group-containing polycarbonate resin is preferably 40 mgKOH / g or more, more preferably 70 mgKOH / g or more, and even more preferably 90 mgKOH / g or more, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, and is preferably 300 mgKOH / g or less, more preferably 250 mgKOH / g or less, and even more preferably 200 mgKOH / g or less.

[0075] When the hydroxyl group-containing compound (A) contains a hydroxyl group-containing polycarbonate resin, the content of the hydroxyl group-containing polycarbonate resin is, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, based on the total solid content of the hydroxyl group-containing compound (A), and is preferably 95% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less.

[0076] The hydroxyl group-containing compound (A) may also contain a hydroxyl group-containing monomer. Examples of the hydroxyl group-containing monomer include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylene glycol, tetramethylene glycol, 3-methyl-4,3-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2 , 5-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, hydroxypivalic acid neopentyl glycol ester, hydrogenated bisphenol A, hydrogenated bisphenol F, glycerin, trimethylolethane, trimethylolpropane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, mannite, hydroxyacetone, 4-(2-hydroxyethyl)morpholine, benzyl alcohol, 2-phenylethanol, 2-phenoxyethanol, naphthalen-1-ol, (1,3-benzoxol-5-yl)methanol, nonylphenol, dinonylphenol, nonylphenol ethoxylate, monostyrenated phenol, distyrenated phenol, tristyrenated phenol, any combination thereof, and the like.

[0077] When the hydroxyl group-containing compound (A) contains the hydroxyl group-containing monomer, the content of the hydroxyl group-containing monomer is preferably within a range of 5 to 60 mass %, more preferably within a range of 5 to 40 mass %, and even more preferably within a range of 5 to 30 mass %, based on the total solid content of the hydroxyl group-containing compound (A), from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold.

[0078] In the coating composition according to the present disclosure, the content of the hydroxyl group-containing compound (A) is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, based on the total amount of the coating composition, from the viewpoints of reducing the VOC content in the resulting coating composition, and improving the adhesion of the coating film to the polycarbonate resin substrate and the mold releasability, and is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 50% by mass or less.

[0079] [Polyisocyanate Compound (B)] The polyisocyanate compound (B) is a compound having at least two isocyanate groups in one molecule, and includes, for example, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and derivatives of the polyisocyanates.

[0080] Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate, methyl 2,6-diisocyanatohexanoate (common name: lysine diisocyanate), aliphatic diisocyanates such as 2-isocyanatoethyl 2,6-diisocyanatohexanoate, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, and 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyloctane.

[0081] Examples of the alicyclic polyisocyanate include alicyclic diisocyanates such as 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (common name: hydrogenated xylylene diisocyanate) or a mixture thereof, and norbornane diisocyanate; 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2-(3-isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2.2.1)hepta 2-(3-isocyanatopropyl)-2,6-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 3-(3-isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-3-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, 6-(2-isocyanatoethyl)-2-isocyanato alicyclic triisocyanates such as 2-isocyanatoethyl-3-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane, and 6-(2-isocyanatoethyl)-2-isocyanatomethyl-2-(3-isocyanatopropyl)-bicyclo(2.2.1)heptane.

[0082] Examples of the araliphatic polyisocyanate include araliphatic diisocyanates such as 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene (common name: tetramethylxylylene diisocyanate) or a mixture thereof; and araliphatic triisocyanates such as 1,3,5-triisocyanatomethylbenzene.

[0083] Examples of the aromatic polyisocyanate include aromatic diisocyanates such as m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 2,4'- or 4,4'-diphenylmethane diisocyanate or mixtures thereof, 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, 4,4'-toluidine diisocyanate, and 4,4'-diphenyl ether diisocyanate; aromatic triisocyanates such as triphenylmethane-4,4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, and 2,4,6-triisocyanatotoluene; and aromatic tetraisocyanates such as 4,4'-diphenylmethane-2,2',5,5'-tetraisocyanate. Examples of the derivatives of the polyisocyanates include dimers, trimers, biurets, allophanates, uretdione, uretonimine, isocyanurates, iminooxadiazinedione, polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI), crude TDI, and the like of the polyisocyanate compounds.

[0084] The polyisocyanates and derivatives thereof may be used alone or in combination of two or more thereof. Among these polyisocyanates, it is preferable to use aliphatic diisocyanates, aliphatic triisocyanates, alicyclic diisocyanates, araliphatic diisocyanates, and derivatives thereof alone or in combination of two or more thereof.

[0085] The polyisocyanate compound (B) may be a prepolymer obtained by reacting the polyisocyanate or a derivative thereof with a compound reactive with the polyisocyanate under conditions of excess isocyanate groups. Examples of the compound reactive with the polyisocyanate include compounds having active hydrogen groups such as hydroxyl groups and amino groups. Specific examples of the polyisocyanate that can be used include polyhydric alcohols, low-molecular-weight polyester resins, amines, and water. The polyhydric alcohols described in the section on the hydroxyl-containing polyester resins can be used.

[0086] From the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, the polyisocyanate compound (B) is used so that the ratio of isocyanate groups in the polyisocyanate compound (B) to hydroxyl groups in the hydroxyl group-containing compound (A) is preferably 0.7 or more, more preferably 0.9 or more, and preferably 2.0 or less, more preferably 1.5 or less.

[0087] Furthermore, in the coating composition according to the present disclosure, the content of the polyisocyanate compound (B) is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, based on the total amount of the coating composition, from the viewpoints of adhesion of the coating film to the polycarbonate resin substrate and releasability from the mold, and is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less.

[0088] [Curing catalyst (C)] The coating composition according to the present disclosure contains a curing catalyst (C). By including the curing catalyst (C) in the coating composition according to the present disclosure, the mold releasability of the coating film formed can be improved. Examples of the curing catalyst (C) include tin octoate, dibutyltin diacetate, dibutyltin di(2-ethylhexanoate), dibutyltin dilaurate, dioctyltin diacetate, dioctyltin di(2-ethylhexanoate), dioctyltin dineodecanoate, dioctyltin diversatate, dibutyltin oxide, dibutyltin sulfide, dioctyltin oxide, dibutyltin fatty acid salts, lead 2-ethylhexanoate, zinc octoate, zinc naphthenate, zinc fatty acids, bismuth octanoate, bismuth 2-ethylhexanoate, bismuth oleate, bismuth neodecanoate, Organometallic compounds such as bismuth versatate, bismuth naphthenate, cobalt naphthenate, calcium octoate, copper naphthenate, tetra(2-ethylhexyl)titanate, tetra(n-butyl)titanate, titanium diisopropoxybis(acetylacetonate), titanium tetraacetylacetonate, titanium diisopropoxybis(ethylacetoacetate), titanium butoxide dimer, zirconium tetra-normal propoxide, zirconium tetra-normal butoxide, zirconium tetraacetylacetonate, and zirconium tributoxymonoacetylacetonate;Triethylamine, N,N'-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), 1,5-diazabicyclo[4.3.0]-pentane (PBB ... ]-5-nonene (DBN), N-methyl-N'-(2-dimethylaminoethyl)piperazine, N-ethylmorpholine, 1,2-dimethylimidazole, dimethylethanolamine, dimethylaminoethoxyethanol, N-methyl-N'-(2-hydroxyethyl)piperazine, 2-hydroxyethyl-1,4-diazabicyclo[2.2.2]octane, 1,1'-{[3-(dimethylamino)propyl]imino}bis(2-propanol), bis(2-dimethylaminoethyl)ether, bis(2-morpholinoethyl)ether, and other tertiary amine compounds, neutralized salts of the tertiary amine compounds; quaternary ammonium salts, such as carboxylates of tetraalkylammonium, tetraarylammonium, and alkylarylammonium, and halides of tetraalkylammonium, tetraarylammonium, and alkylarylammonium, and any combination thereof;

[0089] In view of the mold releasability of the coating film formed, the coating composition according to the present disclosure may contain, as the curing catalyst (C), dioctyltin diversatate, dibutyltin dilaurate, dioctyltin diacetate, dioctyltin dineodecanoate, zinc octoate, zinc naphthenate, zinc fatty acids, bismuth octanoate, bismuth 2-ethylhexanoate, bismuth oleate, bismuth neodecanoate, bismuth versatate, bismuth naphthenate, tetra(2-ethylhexyl) Titanate, tetra(n-butyl)titanate, titanium diisopropoxybis(acetylacetonate), titanium tetraacetylacetonate, titanium diisopropoxybis(ethylacetoacetate), titanium butoxide dimer, zirconium tetra-normal-propoxide, zirconium tetra-normal-butoxide, zirconium tetraacetylacetonate, zirconium tributoxymonoacetylacetonate, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and 1,5-diazabicyclo[4.3.0]octane (DABCO). ]-5-nonene (DBN), dioctyltin diversatate, dibutyltin dilaurate, dioctyltin diacetate, dioctyltin dineodecanoate, zinc octylate, zinc naphthenate, zinc fatty acids, zirconium tetra-n-propoxide, zirconium tetra-n-butoxide, zirconium tetraacetylacetonate, zirconium tributoxymonoacetylacetonate, 1,4-diazabicyclo[2.2.2.]octane (DABCO), 1,8-diazabicyclo[5.4.0.]-7-undecene (DBU), and 1,5-diazabicyclo[4.3.0.]octane (DABCO). ]-5-nonene (DBN), and more preferably contains at least one curing catalyst selected from dioctyltin diversatate, dibutyltin dilaurate, dioctyltin diacetate, and dioctyltin dineodecanoate.

[0090] The content of the curing catalyst (C) is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and preferably 2.0 mass % or less, more preferably 1.5 mass % or less, based on the total amount of the coating composition, from the viewpoints of mold releasability and smoothness of the coating film to be formed.

[0091] [Dehydrating agent (D)] The coating composition according to the present disclosure preferably contains a dehydrating agent (D) from the viewpoint of smoothness of the coating film to be formed, etc. As the dehydrating agent (D), at least one dehydrating agent selected from inorganic dehydrating agents and organic dehydrating agents can be used.

[0092] Examples of the inorganic dehydrating agent include calcium compounds such as calcium hydride, calcium oxide (quicklime), calcium chloride, and calcium sulfate (gypsum); barium compounds such as barium oxide; magnesium compounds such as magnesium sulfate; sodium compounds such as sodium sulfate and sodium carbonate; copper compounds such as copper sulfate; inorganic silicon compounds such as silica gel; aluminum compounds such as aluminum oxide (hydraulic alumina, lithium aluminum hydride, amorphous silica alumina, and crystalline aluminosilicates (molecular sieves); and any combinations thereof.

[0093] Examples of the organic dehydrating agent include alkyl orthoformate; alkyl orthoacetate; alkyl orthoborate; vinylsilane; alkoxysilane compounds; monoisocyanate compounds; aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides such as benzoic anhydride, and any combination thereof.

[0094] When the coating composition according to the present disclosure contains the dehydrating agent (D), from the viewpoint of the mold releasability and smoothness of the coating film to be formed, the content of the dehydrating agent (D) is preferably 0.1 mass % or more, more preferably 0.3 mass % or more, and preferably 3.0 mass % or less, more preferably 2.5 mass % or less, based on the total amount of the coating composition.

[0095] [Internal Release Agent (E)] When the coating composition according to the present disclosure is used as an in-mold coating coating composition, it is preferable to contain an internal release agent (E) from the viewpoint of the releasability between the formed coating film and the mold. Examples of the internal mold release agent (E) include saturated fatty acids such as stearic acid and palmitic acid; saturated fatty acid salts such as zinc stearate, aluminum stearate, magnesium stearate, calcium stearate, sodium stearate, potassium stearate, barium stearate, zinc palmitate, aluminum palmitate, magnesium palmitate, calcium palmitate, and sodium palmitate; saturated fatty acid amides such as lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, N,N-dimethyllauric acid amide, N,N-dimethylmyristic acid amide, N,N-dimethylpalmitic acid amide, N,N-dimethylstearic acid amide, N,N-diethyllauric acid amide, N,N-diethylmyristic acid amide, N,N-diethylpalmitic acid amide, and N,N-diethylstearic acid amide; unsaturated fatty acids such as palmitoleic acid and oleic acid; zinc palmitoleate, aluminum palmitoleate, palmitoleate, and palmitic acid amide. unsaturated fatty acid salts such as magnesium lumitoleate, calcium palmitoleate, sodium palmitoleate, potassium palmitoleate, barium palmitoleate, zinc oleate, aluminum oleate, magnesium oleate, calcium oleate, sodium oleate, potassium oleate, and barium oleate; unsaturated fatty acid amides such as palmitoleic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, N-oleyl palmitic acid amide, N-stearyl erucic acid amide, N,N-dimethyl oleic acid amide, and N,N-diethyl oleic acid amide; nonionic surfactants such as polyoxyethylene alkyl ethers and sorbitan alkyl esters; fluorine-based compounds such as polytetrafluoroethylene, fluoropolyethers, perfluoroalkyl esters, and perfluoroalkyl ester salts; phosphate ester compounds such as phosphate monoesters and / or phosphate diesters having alkyl chains or oxyethylene chains;Examples of the fatty acid esters include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearate monosorbitate, stearyl stearate, palmitic acid monoglyceride, palmitic acid diglyceride, palmitic acid triglyceride, behenic acid monoglyceride, behenic acid diglyceride, behenyl behenate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, stearyl stearate, palmityl palmitate, methyl stearate, butyl stearate, methyl laurate, methyl palmitate, isopropyl palmitate, biphenyl biphenate, sorbitan monostearate, and 2-ethylhexyl stearate; soybean oil lecithin, silicone oil, and fatty acid alcohol dibasic acid esters; and any combination thereof. ;

[0096] From the viewpoints of the adhesion of the coating film to the polycarbonate resin substrate and the releasability from the mold, the internal release agent (E) preferably contains a fatty acid amide, more preferably contains a fatty acid tertiary amide, and even more preferably contains a fatty acid tertiary dimethylamide.

[0097] Examples of the fatty acid amides include saturated fatty acid amides such as lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, N,N-dimethyllauric acid amide, N,N-dimethylmyristic acid amide, N,N-dimethylpalmitic acid amide, N,N-dimethylstearic acid amide, N,N-diethyllauric acid amide, N,N-diethylmyristic acid amide, N,N-diethylpalmitic acid amide, and N,N-diethylstearic acid amide; and unsaturated fatty acid amides such as palmitoleic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, N-oleylpalmitic acid amide, N-stearylerucic acid amide, N,N-dimethyloleic acid amide, and N,N-diethyloleic acid amide.

[0098] Commercially available products can be used as the internal release agent containing the fatty acid amide. Examples of commercially available products include "INT-120IMC" (trade names, manufactured by Axel Plastics), "Amide AP-1", "Diamid Y", "Diamid O-200", and "Diamid I-200" (trade names, manufactured by Mitsubishi Chemical Corporation), "Neutron", "Neutron-2", "Neutron-S", "Neutron BNT-22H", "Neutron PNT-34", and "Neutron SNT-F" (trade names, manufactured by Nippon Fine Chemicals Co., Ltd.), "Alflo S-10", "Alflo E-10", and "Alflo P-10" (trade names, manufactured by NOF Corporation), "Armoslip CP Powder", "Armoslip HT Powder", and "Armoslip E" (trade names, manufactured by Lion Specialty Chemicals Co., Ltd.), "Fatty Acid Amide S", "Fatty Acid Amide O-N", and "Fatty Acid Amide E" (trade names, manufactured by Kao Corporation).

[0099] When the internal release agent (E) contains the fatty acid amide, the content of the fatty acid amide is preferably in the range of 30 to 100% by mass, more preferably in the range of 50 to 100% by mass, and even more preferably in the range of 70 to 100% by mass, based on the total amount of the internal release agent (E), from the viewpoints of the adhesion of the coating film to the polycarbonate resin substrate and the releasability from the mold.

[0100] Examples of the fatty acid tertiary amide include N,N-dimethyllauric amide, N,N-dimethylmyristic amide, N,N-dimethylpalmitic amide, N,N-dimethylstearic amide, N,N-diethyllauric amide, N,N-diethylmyristic amide, N,N-diethylpalmitic amide, N,N-diethylstearic amide, and N,N-dimethyloleic amide. Commercially available products can be used as the internal release agent containing the fatty acid tertiary amide. An example of a commercially available product is "INT-120IMC" (trade name, manufactured by AXEL PLASTICS).

[0101] When the internal release agent (E) contains a fatty acid tertiary amide, the content of the fatty acid tertiary amide is preferably within the range of 20 to 100% by mass, more preferably within the range of 35 to 100% by mass, and even more preferably within the range of 50 to 100% by mass, based on the total amount of the internal release agent (E), from the viewpoints of adhesion of the coating film formed to the polycarbonate resin substrate and releasability from the mold. Examples of the fatty acid tertiary dimethylamide include N,N-dimethyllauric acid amide, N,N-dimethylmyristic acid amide, N,N-dimethylpalmitic acid amide, N,N-dimethylstearic acid amide, and N,N-dimethyloleic acid amide. Commercially available products can be used as the internal release agent containing the fatty acid tertiary dimethylamide. Examples of commercially available products include "INT-120IMC" (trade name, manufactured by AXEL PLASTICS).

[0102] When the internal release agent (E) contains the fatty acid tertiary dimethylamide, the content of the fatty acid tertiary dimethylamide is preferably in the range of 20 to 100% by mass, more preferably in the range of 35 to 100% by mass, and even more preferably in the range of 50 to 100% by mass, based on the total amount of the internal release agent (E), from the viewpoints of the adhesion of the coating film to the polycarbonate resin substrate and the releasability from the mold.

[0103] When the in-mold coating coating composition according to the present disclosure contains the above-mentioned internal release agent (E), the content of the internal release agent (E) is, from the viewpoints of adhesion of the formed coating film to the polycarbonate resin substrate and releasability from the mold, preferably 0.12 mass % or more, more preferably 0.15 mass % or more, even more preferably 0.18 mass % or more, and preferably 2.0 mass % or less, more preferably 1.5 mass % or less, even more preferably 1.0 mass % or less, based on the total amount of the in-mold coating coating composition.

[0104] [Other Components] The coating composition according to the present disclosure may further contain an ultraviolet absorber and / or a light stabilizer in addition to the above. Furthermore, the coating composition may optionally contain other additives commonly used in the field of coating, such as a crosslinker, a solvent (organic solvent, water), a pigment, an antioxidant, a surface conditioner, an antifoaming agent, an emulsifier, a surfactant, an antifouling agent, a wetting agent, a thickener, a dye, a scratch resistance improver, a gloss adjuster, etc.

[0105] <Ultraviolet Absorber> As the ultraviolet absorber, conventionally known ones can be used, for example, benzotriazole-based absorbers, triazine-based absorbers, salicylic acid derivative-based absorbers, benzophenone-based absorbers, etc. Furthermore, the ultraviolet absorber may have a polymerizable unsaturated group.

[0106] Specific examples of the benzotriazole-based absorbents include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2-(2'-hydroxy-4'-octoxyphenyl)benzotriazole, 2-{2'-hydroxy-3'-(3'',4'',5'',6''-tetrahydrophthalimidomethyl)-5'-methylphenyl}benzotriazole, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and the like.

[0107] Specific examples of the triazine-based absorbents include 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-1,3,5-triazine, 2-[4((2-hydroxy-3-dodecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-((2-hydroxy-3-tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine. Specific examples of the salicylic acid derivative-based absorbents include phenyl salicylate, p-octylphenyl salicylate, and 4-tert-butylphenyl salicylate.

[0108] Specific examples of the benzophenone-based absorbents include 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, and naphthalene. Examples include thorium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, resorcinol monobenzoate, 2,4-dibenzoylresorcinol, 4,6-dibenzoylresorcinol, hydroxydodecylbenzophenone, and 2,2'-dihydroxy-4(3-methacryloxy-2-hydroxypropoxy)benzophenone.

[0109] Commercially available examples of the ultraviolet absorber include "TINUVIN 1130," "TINUVIN 900," "TINUVIN 928," "TINUVIN 384-2," "TINUVIN 479," "TINUVIN 477," "TINUVIN 405," "TINUVIN 400" (trade names manufactured by BASF, TINUVIN is a registered trademark), and "RUVA 93" (trade name manufactured by Otsuka Chemical Co., Ltd.).

[0110] When the coating composition according to the present disclosure contains the above-mentioned ultraviolet absorber, the content of the ultraviolet absorber is, from the viewpoint of the weather resistance of the coating film to be formed and the like, preferably 0.1 mass % or more, more preferably 0.2 mass % or more, even more preferably 0.3 mass % or more, based on the total amount of the coating composition, and is preferably 10 mass % or less, more preferably 5.0 mass % or less, even more preferably 3.0 mass % or less.

[0111] <Light Stabilizer> The light stabilizer is used as a radical chain inhibitor that captures active radical species generated during the deterioration process of the coating film, and examples thereof include light stabilizers of hindered amine compounds.

[0112] Examples of the hindered amine compound include bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(N-methyl-2,2,6,6-tetramethyl-4-piperidinyl)sebacate, 4-benzoyloxy-2,2',6,6'-tetramethylpiperidine, bis(1,2,2,6,6-pentamethyl-4-piperidyl){[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl}butylmalonate, Examples of the light stabilizer include, but are not limited to, monomeric types such as methyl acrylate, methyl meth ...

[0113] Examples of commercially available products of the light stabilizer include "TINUVIN 123," "TINUVIN 152," "TINUVIN 249," and "TINUVIN 292" (trade names, manufactured by BASF, TINUVIN is a registered trademark), "HOSTAVIN 3058" (trade name, manufactured by Clariant, Hostavin is a registered trademark), and "ADK STAB LA-82" (trade name, manufactured by ADEKA Corporation, ADK STAB is a registered trademark).

[0114] When the coating composition according to the present disclosure contains the above-mentioned light stabilizer, the content of the light stabilizer is, from the viewpoint of the weather resistance of the coating film to be formed and the like, preferably 0.1 mass % or more, more preferably 0.2 mass % or more, even more preferably 0.3 mass % or more, based on the total amount of the coating composition, and preferably 10 mass % or less, more preferably 7.5 mass % or less, even more preferably 5.0 mass % or less.

[0115] <Solvent> Examples of the solvent that can be used include organic solvents, water, etc. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based solvents such as ethyl acetate, butyl acetate, methyl benzoate, ethyl ethoxypropionate, ethyl propionate, and methyl propionate; ether-based solvents such as tetrahydrofuran, dioxane, and dimethoxyethane; glycol ether-based solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; aromatic solvents such as toluene, xylene, and "Swasol 1000" (trade name, high-boiling point petroleum solvent, manufactured by Cosmo Oil Co., Ltd.); and aliphatic hydrocarbon-based solvents such as hexane and heptane.

[0116] The content of the solvent in the coating composition according to the present disclosure is within the range of 0 to 10 mass % based on the total amount of the coating composition. From the viewpoint of reducing the VOC content in the resulting coating composition, the content of the solvent in the coating composition according to the present disclosure is preferably within the range of 0 to 5 mass %, and more preferably within the range of 0 to 3 mass %.

[0117] <Pigment> Examples of the pigment include luster pigments, color pigments, extender pigments, any combination thereof, etc. Examples of the luster pigment include aluminum (including vapor-deposited aluminum), copper, zinc, brass, nickel, glass flake, aluminum oxide, mica, aluminum oxide coated with titanium oxide and / or iron oxide, and mica coated with titanium oxide and / or iron oxide.

[0118] Examples of the color pigments include titanium oxide, zinc oxide, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, threne pigments, perylene pigments, dioxazine pigments, diketopyrrolopyrrole pigments, heat-shielding pigments, etc. Examples of the extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, alumina white, etc.

[0119] When the coating composition according to the present disclosure contains the above-mentioned pigment, the content of the pigment is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, even more preferably 0.3 mass % or more, based on the total amount in the coating composition, from the viewpoints of reducing the VOC content in the resulting coating composition and improving the adhesion of the coating film formed to the polycarbonate resin substrate, and is preferably 40 mass % or less, more preferably 30 mass % or less, even more preferably 20 mass % or less.

[0120] <Method for forming a coating film using a coating composition> A coating composition according to the present disclosure is applied to a substrate to form a wet coating film (uncured coating film), and the wet coating film is then cured to form the desired coating film. The substrate is preferably made of a resin material from the viewpoints of adhesion of the coating film to be formed and releasability of the coating film to be formed from a mold, etc.

[0121] Examples of the resin material include polycarbonate resin, acrylic resin such as polymethyl methacrylate, polyester resin such as polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate, polybutylene terephthalate, epoxy resin typified by commercially available products such as Epicoat (trade name: manufactured by Yuka Shell Epoxy Co., Ltd.), polyimide resin, novolac resin, phenol resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-ethylene-styrene (AES) resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-ethylene-styrene (AES) resin, acrylic ... Examples of suitable materials include tolyl-styrene-acrylate (ASA) resins, vinyl chloride resins, vinylidene chloride resins, polyurethane resins, cellulose ester resins (e.g., triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetylpropionyl cellulose, nitrocellulose), polyamide resins, polystyrene resins (e.g., syndiotactic polystyrene), polyolefin resins (e.g., polypropylene, polyethylene, polymethylpentene), polysulfone resins, polyethersulfone resins, polyarylate resins, polyetherimide resins, polyetherketone resins, various fiber-reinforced plastic materials (hereinafter sometimes abbreviated as FRP materials or simply FRP), as well as polymer alloys thereof, recycled materials thereof, etc. Furthermore, the resin materials may be mixed with compounds containing reactive functional groups such as hydroxyl groups, amino groups, mercapto groups, silanol groups, vinyl groups, and epoxy groups, as well as wood fibers, cellulose nanofibers, kenaf, etc., to form the substrate.

[0122] When the substrate according to the present disclosure is a resin material, the resin material is preferably at least one resin material selected from polycarbonate resin and a polymer alloy of polycarbonate resin and other resin. Furthermore, the substrate may be, for example, a resin material coated with a primer paint, an intermediate paint, or a top coat paint, thereby forming a primer layer, an intermediate coat layer, or a top coat layer in advance. The substrate may also be treated (physical treated) by at least one physical method selected from plasma treatment, corona discharge treatment, active energy ray treatment, flame treatment, blast treatment, polishing treatment, etc.

[0123] It is preferable that the coating composition of the present disclosure is directly applied on substrate.In addition, the application of the object to be coated with the coating composition of the present disclosure is not particularly limited, and can be exemplified as outer panels of automobile bodies such as passenger cars, trucks, motorcycles, buses, etc.; automobile interior and exterior parts such as bumpers, center pillars, mirrors, door handles, instrument panels, door trims, center consoles, etc.; furniture and building materials related parts such as chairs, vanity mirrors, window frames, gates, etc.; outer panels of household electrical appliances such as mobile phones, audio equipment, etc.

[0124] The method for applying the coating composition according to the present disclosure to a substrate is not particularly limited. For example, the coating composition can be applied by air spray, airless spray, rotary atomizer, dip coating, applicator, brush, roller, in-mold coating, etc. Electrostatic application may be performed during application.

[0125] The coating film thickness of the coating composition according to the present disclosure is, in terms of the mold releasability of the coating film formed, preferably 70 μm or more, more preferably 80 μm or more, and even more preferably 90 μm or more, in terms of the cured film thickness, and is preferably 1000 μm or less, more preferably 900 μm or less, and even more preferably 800 μm or less. The coating composition according to the present disclosure can be cured on the substrate to which it is applied by heating.

[0126] <Heating> The heating can be carried out by any suitable method known in the art. Specifically, the heating can be carried out using, for example, hot air, hot gas, an infrared heater, an IR radiator, an oven, a heated roller, a hot press, a microwave, etc. From the viewpoint of ease of operation, the heating is preferably carried out by hot air, an infrared heater, a hot press, etc.

[0127] The heating temperature is preferably 30° C. or higher, more preferably 50° C. or higher, and even more preferably 60° C. or higher, from the viewpoints of productivity, workability, adhesion of the coating film to the polycarbonate resin substrate, releasability from a mold, etc., and is preferably 130° C. or lower, more preferably 120° C. or lower, and even more preferably 110° C. or lower. The heating time is preferably 20 seconds or higher, more preferably 40 seconds or higher, and is preferably 60 minutes or lower, more preferably 10 minutes or lower, from the viewpoints of productivity, workability, adhesion of the coating film to the polycarbonate resin substrate, releasability from a mold, etc.

[0128] The coating composition according to the present disclosure preferably has a strength of 60 N / mm 2 More preferably, 70 N / mm 2 More preferably, 80 N / mm 2 and preferably has a Martens hardness of 150 N / mm 2 or less, more preferably 140 N / mm 2 More preferably, 130 N / mm 2 It has the following Martens hardness:

[0129] The Martens hardness is measured as follows: (i) The coating composition is applied to a polycarbonate resin substrate so that the film thickness after drying is 200 μm to form an uncured coating film; (ii) The uncured coating film is heat-cured at 80° C. for 1 minute to form a cured coating film; (iii) A pyramidal diamond indenter is pressed into the cured coating film at a temperature of 23° C. for 20 seconds under conditions of a maximum test load of 20 mN.

[0130] The Martens hardness in this specification can be measured using a Fischerscope (registered trademark) HM2000S (trade name, manufactured by Fischer Instruments Co., Ltd.). The Martens hardness is measured by pressing an indenter into the surface of the coating film for 20 seconds at a maximum load of 20 mN in an atmosphere of 23°C and 50% RH. A Vickers pyramid (material: diamond) is used as the indenter, and the position of the sample is adjusted so that the indenter's point of action is near the center of one prism peak.

[0131] The specific procedure for measuring Martens hardness in this specification is as follows: (1) Press the indenter down over 20 seconds to a maximum load of 20 mN. (2) After reaching the maximum load, release the load over 20 seconds. (3) Repeat steps (1) and (2) while changing the measurement position, and collect three data points for each sample. (4) Calculate the Martens hardness by dividing the test load by the surface area penetrated by the indenter, and take the average of the three values. The coated plate used for measuring Martens hardness is "Makrolon AL2447" (trade name, manufactured by Covestro, 100 mm x 100 mm x 2 mm flat polycarbonate resin substrate) coated with a film to a dry film thickness of 200 μm, which is then heated and cured at 80°C for 1 minute.

[0132] The coating composition according to the present disclosure can also be suitably used in coating by an in-mold coating method, which typically allows the use of coating compositions with low VOC content and further reduces the air conditioning energy required during coating, thereby offering the advantage of reducing the environmental impact.

[0133] [In-mold coating method] The in-mold coating method according to the present disclosure comprises the steps of injecting the coating composition according to the present disclosure (hereinafter, when the coating composition according to the present disclosure is used in the in-mold coating method, it will be referred to as the in-mold coating coating composition) between a molded substrate and an inner wall of a mold, curing the in-mold coating coating composition, and then removing the coated molded article from the mold.

[0134] The in-mold coating method can be any conventional method of molding and coating in a mold without any particular limitations. Specifically, for example, the methods described in JP-A-2000-141407 and JP-A-2008-525212 can be used.

[0135] The resin molding mold used for molding the resin material and the in-mold coating mold used for in-mold coating with the in-mold coating composition may be the same or different. When the resin molding mold and the in-mold coating mold are the same, for example, a heated and molten resin material is injected in an injection cylinder between the resin molding molds having the shape of the desired molded product, and then cooled and pressurized in the resin molding mold to form a molded product from the resin material. Then, the resin molding mold is separated from the surface of the molded product made of the resin material. Next, a gap sufficient for injecting the in-mold coating composition is provided between the surface of the molded product made of the resin material and the in-mold coating mold, and the in-mold coating composition is injected between the surface of the molded product made of the resin material and the inner wall of the in-mold coating mold, and the in-mold coating mold is closed to form an uncured in-mold coating film on the molded product made of the resin material. Next, the uncured in-mold coating film formed on the molded product made of the resin material is heated and molded into the desired shape, thereby obtaining an in-mold coated molded product in which a cured in-mold coating film is formed on the molded product made of the resin material.

[0136] When the resin molding mold and the first coating film coated mold are different, for example, a heated and molten resin material is injected in an injection cylinder between resin molding molds having the shape of the desired molded product, cooled and pressurized in the resin molding mold, the resin material is molded into a molded product, and the resin molding mold is then separated from the surface of the molded product made of the resin material and removed. Next, the in-mold coating mold is brought close to the surface of the resin molded product, a gap sufficient to inject the in-mold coating paint composition is provided between the surface of the molded product made of the resin material and the in-mold coating mold, and the in-mold coating paint composition is injected between the surface of the molded product made of the resin material and the inner wall of the in-mold coating mold. The in-mold coating mold is then closed, and an uncured in-mold coating film is formed on the molded product made of the resin material. Next, the uncured in-mold coating film formed on the molded product made of the resin material is heated and molded into the desired shape, resulting in an in-mold coated molded product with a cured in-mold coating film formed on the molded product made of the resin material.

[0137] From the viewpoint of releasability between the in-mold coated molded article and the in-mold coated mold, an external mold release agent may be applied to the mold, such as a fluorine-based, silicone-based, surfactant-based, or wax-based external mold release agent.

[0138] The heating temperature when melting the resin in the injection cylinder is determined arbitrarily depending on the type of resin material, etc., but is preferably 70 to 300° C. The temperature of the mold when injecting the resin material is determined arbitrarily depending on the molding time, type of resin material, etc., but is preferably 30 to 120° C. The molding time for the resin material may be until the resin material is completely solidified, but it is sufficient if the resin material is solidified to a strength that does not impair the molded shape when the in-mold coating paint composition is injected, and is usually preferably about 20 seconds to 60 minutes.

[0139] The amount of the in-mold coating paint composition injected into the in-mold coating mold is an amount sufficient to obtain the desired film thickness, and from the viewpoint of the releasability of the formed coating film from the mold, the amount is an amount sufficient to obtain a cured film thickness of preferably 70 μm or more, more preferably 80 μm or more, and even more preferably 90 μm or more, and is an amount sufficient to obtain a cured film thickness of preferably 1000 μm or less, more preferably 900 μm or less, and even more preferably 800 μm or less.

[0140] The heating temperature when heating the uncured in-mold coating film is preferably 20°C or higher, more preferably 40°C or higher, even more preferably 60°C or higher, and preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower. The heating time when heating the uncured in-mold coating film is preferably 20 seconds or higher, more preferably 30 seconds or higher, even more preferably 40 seconds or higher, and preferably 10 minutes or lower, more preferably 5 minutes or lower, and even more preferably 4 minutes or lower. When heating and curing the uncured in-mold coating film, it is preferable to apply pressure. When applying pressure, the pressure is preferably within the range of 2 to 14 MPa, from the viewpoint of the adhesion of the coating film to the polycarbonate resin substrate to be formed.

[0141] The present disclosure will be explained in more detail below with reference to Production Examples, Examples, and Comparative Examples. Note that these Production Examples, Examples, and Comparative Examples are merely illustrative and are not intended to limit the scope of the present disclosure. In the Production Examples, Examples, and Comparative Examples, "parts" and "%" are based on mass unless otherwise specified. Furthermore, the film thickness of the coating film is based on the cured coating film. The components used in the following examples are as follows.

[0142] [Preparation of Hydroxyl-Containing Acrylic Resin Composition] [Preparation Example 1] 40 parts of 1,4-cyclohexanedimethanol were charged into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen inlet tube, and dropping device. The charged liquid was stirred at 150°C while nitrogen gas was blown into the reaction vessel, and a monomer mixture consisting of 25 parts of styrene, 15 parts of methyl methacrylate, 20 parts of n-butyl acrylate, 40 parts of 2-hydroxyethyl methacrylate, and 8 parts of di-tertiary amyl peroxide (polymerization initiator) was added dropwise to the reaction vessel at a uniform rate over 4 hours. The contents of the reaction vessel were then aged at 150°C for 1 hour and then cooled to obtain a hydroxyl-containing acrylic resin (A2-1) composition with a solids concentration of 100% by mass. The hydroxyl value of the hydroxyl-containing acrylic resin in the resulting hydroxyl-containing acrylic resin (A2-1) composition was 172 mgKOH / g, the number average molecular weight was 1,900, and the glass transition temperature was 39.0°C.

[0143] [Production Example 2] 40 parts of 1,4-cyclohexanedimethanol were charged into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen inlet tube, and dropping device. The charged liquid was stirred at 150°C while nitrogen gas was blown into the reaction vessel, and a monomer mixture consisting of 30 parts of n-butyl acrylate, 30 parts of 2-ethylhexyl acrylate, 40 parts of 2-hydroxyethyl methacrylate, and 8 parts of di-tertiaryamyl peroxide (polymerization initiator) was added dropwise to the reaction vessel at a uniform rate over 4 hours. The contents of the reaction vessel were then aged at 150°C for 1 hour and then cooled to obtain a hydroxyl-containing acrylic resin (A2-2) composition with a solids concentration of 100% by mass. The hydroxyl value of the hydroxyl-containing acrylic resin in the resulting hydroxyl-containing acrylic resin (A2-2) composition was 172 mgKOH / g, the number average molecular weight was 1,900, and the glass transition temperature was -27.1°C.

[0144] [Production Example 3] 40 parts of 1,4-cyclohexanedimethanol were charged into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen inlet tube, and dropping device. The charged liquid was stirred at 150°C while nitrogen gas was blown into the reaction vessel, and a monomer mixture consisting of 30 parts of styrene, 30 parts of methyl methacrylate, 30 parts of 2-ethylhexyl acrylate, 10 parts of 2-hydroxyethyl methacrylate, and 8 parts of di-tertiary amyl peroxide (polymerization initiator) was added dropwise to the reaction vessel at a uniform rate over 4 hours. The contents of the reaction vessel were then aged at 150°C for 1 hour and then cooled to obtain a hydroxyl-containing acrylic resin (A2-3) composition with a solids concentration of 100% by mass. The hydroxyl value of the hydroxyl-containing acrylic resin in the resulting hydroxyl-containing acrylic resin (A2-3) composition was 43 mgKOH / g, the number average molecular weight was 1,900, and the glass transition temperature was 32.6°C.

[0145] [Production Example 4] 40 parts of 1,4-cyclohexanedimethanol were charged into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen inlet tube, and dropping device. The charged liquid was stirred at 150°C while nitrogen gas was blown into the reaction vessel, and a monomer mixture consisting of 25 parts of styrene, 15 parts of methyl methacrylate, 20 parts of 2-ethylhexyl acrylate, 40 parts of 2-hydroxyethyl methacrylate, and 20 parts of di-tertiary amyl peroxide (polymerization initiator) was added dropwise to the reaction vessel at a uniform rate over 4 hours. The contents of the reaction vessel were then aged at 150°C for 1 hour and then cooled to obtain a hydroxyl-containing acrylic resin (A2-4) composition with a solids concentration of 100% by mass. The hydroxyl value of the hydroxyl-containing acrylic resin in the resulting hydroxyl-containing acrylic resin (A2-4) composition was 165 mgKOH / g, the number average molecular weight was 700, and the glass transition temperature was 39.5°C.

[0146] [Production of Pigment Dispersion (P)] [Production Example 5] 4.7 parts of butyl acetate, 1 part of "Raven 5000 ULTRA III POWDER" (trade name, manufactured by BIRLA CARBON, carbon black pigment, solids concentration 100%), 0.1 parts of "SOLSPERSE 5000S" (trade name, manufactured by LUBRISOL, phthalocyanine pigment derivative, solids concentration 100%), and 1 part of "DISPERBYK-2013" (trade name, manufactured by BYK-Chemie, dispersant, solids concentration 100%) were placed in a container equipped with a stirrer and mixed uniformly. The resulting mixed solution was then placed in a wide-mouth glass bottle, and glass beads with a diameter of approximately 1.3 mm were added as a dispersion medium, the bottle was sealed, and the bottle was dispersed for 4 hours using a paint shaker to obtain pigment dispersion (P-1).

[0147] [Production of Coating Composition] [Example 1] Into a vessel equipped with a stirrer were added 25.0 parts of "THEIC-LD" (trade name, manufactured by Shikoku Chemical Industry Co., Ltd., ε-caprolactone-modified tris(2-hydroxyethyl)isocyanurate, number average molecular weight 617, solid content 100%), 50.0 parts of the hydroxyl group-containing acrylic resin (A2-1) composition (solid content 100%) obtained in Production Example 1, 25.0 parts of "PLACCEL 305" (trade name, manufactured by Daicel Corporation, polycaprolactone resin having three hydroxyl groups, number average molecular weight 550, solid content 100%), 60.0 parts of "DESMODUR N3600" (trade name, manufactured by Sumika Covestro Urethane Co., Ltd., isocyanurate of hexamethylene diisocyanate, solid content 100%), and 10.0 parts of "DESMODUR N3600". NZ200 (trade name, manufactured by Sumika Covestro Urethane Co., Ltd., a mixture of isocyanurate of hexamethylene diisocyanate and isocyanurate of isophorone diisocyanate, solid content 100%) 60.0 parts, "Neostan U-830" (trade name, manufactured by Nitto Kasei Co., Ltd., dioctyltin diversatate, solid content 100%) 1.5 parts, methyl orthoacetate (solid content 0%) 1.2 parts, "Amide AP-1" (trade name, manufactured by Mitsubishi Chemical Corporation, stearic acid amide, solid content 100%) 1.5 parts, "BYK-333" (trade name, manufactured by BYK-Chemie Co., Ltd., surface conditioner (polyether-modified polydimethylsiloxane), solid content 100%) 0.1 parts, "TINUVIN 400" (trade name, manufactured by BASF Corporation, triazine-based ultraviolet absorber, solid content 85%) 1.2 parts and "TINUVIN 2.0 parts of "292" (trade name, manufactured by BASF, hindered amine compound light stabilizer, solids concentration 100%) was added and mixed uniformly to obtain In-mold Coating Paint Composition No. 1 with a solids concentration of 99.4%.

[0148] Examples 2 to 53 and Comparative Examples 1 to 3 In-mold coating compositions No. 2 to No. 56 were obtained in the same manner as in Example 1, except that the blending compositions were as shown in Tables 1-1 to 1-4 below. In Tables 1-1 to 1-4, "polycaprolactone resin (A3') having three or more hydroxyl groups in one molecule" is expressed as "polycaprolactone resin (A3')."

[0149]

[0150]

[0151]

[0152]

[0153] The components listed in the table are as follows: (Note 1) "Placcel E2394": Trade name, manufactured by Daicel Corporation, ε-caprolactone-modified tris(2-hydroxyethyl)isocyanurate, number average molecular weight 1000, solid content 100% (Note 2) "THEIC-EP": Trade name, manufactured by Shikoku Chemicals Corporation, propylene oxide-modified tris(2-hydroxyethyl)isocyanurate, number average molecular weight 465, solid content 100% (Note 3) "Placcel 303": Trade name, manufactured by Daicel Corporation, polycaprolactone resin having three hydroxyl groups, number average molecular weight 310, solid content 100% (Note 4) "Placcel 205U": Trade name, manufactured by Daicel Corporation, polycaprolactone resin having two hydroxyl groups, number average molecular weight 530, solid content 100% (Note 5) "Desmophen VPLS" 2249 / 1": Trade name, manufactured by Covestro, hydroxyl group-containing polyester resin, number average molecular weight 400, solid content 100% (Note 6) "Desmodur N3900": Trade name, manufactured by Sumika Covestro Urethane Co., Ltd., polyisocyanate having an iminooxadiazinedione group, solid content 100% (Note 7) "K-KAT A209": Trade name, manufactured by KING INDUSTRIES, zirconium complex, solid content 72.5% (Note 8) "Moldwiz INT-120IMC": Trade name, manufactured by AXEL PLASTICS, fatty acid tertiary dimethylamide-containing mixture, solid content 100% (Note 9) "Daifree FB-962": Trade name, manufactured by Daikin, fluoropolymer, solid content 100%

[0154] [Preparation of In-Mold Coated Molded Article] [Example 54] (Preparation of In-Mold Coated Molded Article) Polycarbonate (PC) resin (Makrolon AL2447, manufactured by Covestro) was filled into an injection molding cylinder and heated to melt at 270°C. The heated and melted polycarbonate resin was then injected into a resin molding die at 80°C, and the pressure was maintained for 30 seconds while cooling to obtain a 100mm x 100mm x 2mm flat-plate-shaped PC resin molded article. Next, the resin molding die was opened, and the in-mold coating paint composition No. 1 obtained in Example 1 was injected between the obtained molded article and the coating film-coated die. The interior of the coating film-coated die was heated to 80°C, and while maintaining the temperature, a molding pressure of 5 MPa was applied and maintained for 1 minute. After that, the coating film-coated die was decompressed, and the coating film-coated die was opened to obtain in-mold coated molded article No. 1, in which a coating film with a cured film thickness of 200 μm was coated on the molded article. 1 was produced.

[0155] [Examples 55 to 106 and Comparative Examples 4 to 6] In-mold coated moldings No. 2 to No. 56 were prepared in the same manner as in Example 54, except that the types of coating compositions were as shown in Table 2 below.

[0156] [Measurement of Martens Hardness] The Martens hardness (N / mm) of each of the cured coating films of the in-mold coated moldings No. 1 to No. 56 was measured. 2 ) was measured using a "Fisherscope (registered trademark) HM2000S" (product name, manufactured by Fischer Instruments Co., Ltd.). The results are also shown in Tables 2-1 to 2-4.

[0157] [Evaluation of In-Mold Coated Molded Products] The cured coating films of each of the in-mold coated molded products No. 1 to No. 56 were evaluated for adhesion to the PC resin substrate, releasability, and smoothness. The evaluation results are shown in Tables 2-1 to 2-4.

[0158] [Adhesion to PC resin substrate] The coating film of each of in-mold coated moldings No. 1 to No. 56 was cut into a grid pattern with a cutter so as to reach the substrate, creating 100 2 mm x 2 mm squares. Next, adhesive cellophane tape was applied to the surface of each of the cut-out coated test panels, and the adhesive cellophane tape was rapidly peeled off at a temperature of 23±2°C and a relative humidity of 50±5% RH. The remaining state of the cross-hatched coating film after peeling was examined, and adhesion was evaluated based on the following evaluation criteria. A, B, and C were considered acceptable.

[0159] [Evaluation criteria] A: 100 cross-hatched coating films remained, and there were no small chips or lifting of the coating film at the edges of the cutter notches. B: 100 cross-hatched coating films remained, and there were small chips or lifting of the coating film at the edges of the cutter notches. C: 90 to 99 cross-hatched coating films remained. D: 80 to 89 cross-hatched coating films remained. E: The number of remaining cross-hatched coating films was 79 or less.

[0160] [Mold Releasability] In the preparation of each of the above in-mold coated molded articles No. 1 to No. 56, when the coating film-coated mold was released, a spatula was inserted into the gap between one of the four corners of the in-mold coated mold and the coating film-coated mold, and the mold release test was performed to release the in-mold coated mold from the coating film-coated mold. If the in-mold coating composition could not be released from the mold, the spatula was removed, and the spatula was inserted again into the gap between one of the four corners on the right and the coating film-coated mold, and the mold release test was performed by lifting the mold in the same manner. The mold release test was performed on all four corners until the in-mold coating composition was released, for a total of up to four times. Furthermore, for in-mold coated molded articles in which peeling of the coating film was observed, the surface of the in-mold coated molded article was observed with the naked eye, the number of peeled coatings was counted, and the mold release property was evaluated based on the following evaluation criteria. A, B, and C were considered acceptable.

[0161] [Evaluation criteria] A: The in-mold coated molded article was released from the mold in the first or second mold release test, and the number of peeled coating films was zero. B: The in-mold coated molded article was released from the mold in the third or fourth mold release test, and the number of peeled coating films was zero. C: The in-mold coated molded article was released from the mold in the first to fourth mold release test, and the number of peeled coating films was one. D: The in-mold coated molded article was released from the mold in the first to fourth mold release test, and the number of peeled coating films was two or more. E: The in-mold coated molded article did not release from the mold even after four mold release tests, or the coating film completely peeled from the substrate.

[0162] [Smoothness] For each of the coating films of in-mold coated moldings No. 1 to No. 56, smoothness was evaluated according to the following evaluation criteria based on the Long Wave (LW) value measured using a "Wave Scan" (trade name, manufactured by BYK Gardner). The smaller the LW value, the higher the smoothness of the coating surface, with A, B, and C being acceptable. [Evaluation criteria] A: The LW value was less than 12. B: The LW value was 12 or more and less than 15. C: The LW value was 15 or more and less than 18. D: The LW value was 18 or more and less than 20. E: The LW value was 20 or more.

[0163]

[0164]

[0165]

[0166]

Claims

1. A paint composition comprising (A) a hydroxyl group-containing compound, (B) a polyisocyanate compound, and (C) a curing catalyst, having a solid content concentration of 90% by mass or more, wherein the hydroxyl group-containing compound (A) contains a hydroxyl group-containing compound (A1) having a nurate ring structure.

2. The paint composition according to claim 1, wherein the content of the hydroxyl group-containing compound (A1) having a nurate ring structure is in the range of 5 to 50% by mass based on the total solid content of the hydroxyl group-containing compound (A).

3. The paint composition according to claim 1 or 2, wherein the hydroxyl group-containing compound (A) contains a hydroxyl group-containing acrylic resin (A2).

4. The paint composition according to any one of claims 1 to 3, wherein the hydroxyl group-containing compound (A) contains a polycaprolactone resin (A3') having 3 or more hydroxyl groups in one molecule.

5. The paint composition according to any one of claims 1 to 4, wherein the content of the curing catalyst (C) is in the range of 0.1 to 2.0% by mass based on the total amount of the paint composition.

6. The paint composition according to any one of claims 1 to 5, further comprising a dehydrating agent (D).

7. When the paint composition is configured such that (i) the paint composition is applied onto a polycarbonate resin substrate so that the film thickness after drying becomes 200 μm to form an uncured coating film, (ii) the uncured coating film is heat-cured at 80° C. for 1 minute to form a cured coating film, and (iii) the Martens hardness is measured by pressing a square pyramid-shaped diamond indenter against the cured coating film at a temperature of 23° C. and a humidity of 50% RH for 20 seconds under the condition that the maximum test load becomes 20 mN, the paint composition according to any one of claims 1 to 6, which has a Martens hardness within the range of 60 to 150 N / mm ２ is configured to have a Martens hardness within the range of.

8. The paint composition according to any one of claims 1 to 7, wherein the paint composition is an in-mold coating paint composition.

9. The paint composition according to claim 8, further comprising an internal mold release agent (E).

10. The paint composition according to claim 9, wherein the internal mold release agent (E) contains a fatty acid amide.

11. An in-mold coating method comprising the step of injecting an in-mold coating paint composition between a molded substrate and the inner wall of a mold, curing the in-mold coating paint composition, and then removing the coated molded article from the mold, wherein the in-mold coating paint composition is the paint composition according to any one of claims 1 to 10.

12. The in-mold coating method according to claim 11, wherein the in-mold coating paint composition further comprises an internal mold release agent (E).

13. The in-mold coating method according to claim 12, wherein the internal mold release agent (E) contains a fatty acid amide.

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