JPH07286133A - Composition for active energy ray curing type coating compound - Google Patents

Abstract

PURPOSE:To provide a composition for active energy ray curing type coating compound having excellent curing properties with active energy rays, adhesiveness to a base, surface smoothness, flexibility, weather resistance and water resistance. CONSTITUTION:The characteristics of this composition for active energy ray curing type coating compound is that it consists of (A) a urethane acrylate which is obtained by reacting the following components (1) to (3), has >=2 repeating units of the component (1), 3-11 urethane bond groups and/or urea bond groups per constituent unit of the component (1) and 1,000-20,000 molecular weight and (B) a polymerizable monomer having <500 molecular weight. The component (1) is a copolyester polyol containing >=40mol% of an aromatic dicarboxylic acid and having 1,000-10,000 molecular weight. The component (2) is a polyisocyanate compound. The component (3) is a compound containing one or more (meth)acryloyl groups and one or more hydroxyl groups.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an active energy ray curable coating composition which has good curability with respect to active energy rays and is excellent in adhesion to metals and plastics, surface smoothness, flexibility, weather resistance and water resistance. Composition.

[0002]

2. Description of the Related Art Unlike general solvent-based paints, active energy ray-curable paints are solvent-free and the active energy ray-curing process has high productivity, resource saving and energy saving. Due to these features, development is progressing as a paint for various applications. However, the active energy ray-curable coating material has poor wettability with respect to the base material, and internal stress due to shrinkage during curing remains, resulting in poor adhesion to the base material.
Also in terms of curability, the curability varied greatly depending on the color of the paint. Further, although the flexibility of the coating film has been required due to higher performance of the coating material, a coating composition having excellent flexibility has poor adhesion to a base material and is poor in weather resistance and water resistance. There was a problem.

[0003]

SUMMARY OF THE INVENTION The present invention was devised to solve the above-mentioned problems of the prior art. The purpose of the present invention is to provide excellent curability for low energy active energy rays, and Another object of the present invention is to provide an active energy ray-curable coating composition having excellent adhesion to plastics, surface smoothness, flexibility, weather resistance, and water resistance.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a polyester polyol having a molecular weight of 1,000 to 20,000 obtained by copolymerizing a specific amount of an aromatic dicarboxylic acid with (2) A urethane acrylate (3) having a molecular weight in a specific range and a urethane or urea group concentration obtained by introducing a compound having at least one (meth) acryloyloxy group and at least one hydrogen group through an isocyanate compound ( A), polymerizable monomer (B)
By using the paint obtained by blending the pigment (C) as necessary, excellent curability and adhesion to active energy rays in the low energy range, surface smoothness, flexibility, weather resistance, and water resistance are obtained. It has been found that an active energy ray-curable coating composition can be obtained.

That is, the active energy ray-curable coating composition of the present invention is obtained by reacting the following (1) to (3) with the number of repeating units of the component (1) being 2 or more and the component ( 1)
3 to 11 urethane bonding groups and /
Alternatively, the molecular weight of the urea-bonded group is 1000 to 200.
No. 00 urethane acrylate (A), a polymerizable monomer (B) having a molecular weight of less than 500, and optionally a pigment (C) are contained in the active energy ray-curable coating composition. (1) Copolyester polyol containing 40 mol% or more of aromatic dicarboxylic acid and having a molecular weight of 1,000 to 10,000 (2) Polyisocyanate compound (3) One or more (meth) acryloyloxy groups and one or more Compounds with hydrogen groups

The (1) copolymerized polyester polyol used in the present invention comprises a dicarboxylic acid component and a glycol component. The aromatic dicarboxylic acid which is an essential component in the present invention is a dicarboxylic acid having a group having aromaticity in the molecule, and examples thereof include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid and 1,5-naphthalic acid. Is a typical example. If necessary, a small amount of tri- and tetracarboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid may be contained. Examples of the dicarboxylic acid copolymerizable with other than the aromatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid and other aliphatic dicarboxylic acids, 1,2-hexahydrophthalic acid, 1,3- Hexahydrophthalic acid,
Aliphatic dicarboxylic acids such as 1,4-hexahydrophthalic acid and perhydronaphthalene dicarboxylic acid, unsaturated dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid, unsaturated fats such as tetrahydrophthalic acid and cyclobutene dicarboxylic acid Examples thereof include oxy acids such as cyclic dicarboxylic acid, p-hydroxyethyloxybenzoic acid and ε-caprolactone.

Examples of the glycol component include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and 1,9-nonanediol. , Neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, spiroglycol, 1,4-phenylene glycol, 1,4-phenylene glycol Ethylene oxide adduct, bisphenol A ethylene oxide adduct and propylene oxide adduct, hydrogenated bisphenol A ethylene oxide adduct and propylene oxide adduct, polyethylene glycol,
Examples include diols such as polypropylene glycol and polytetramethylene glycol. If necessary, a small amount of trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and other triols and tetraols may be contained.

In order to obtain a copolymerized polyester polyol from such a dicarboxylic acid component and a glycol component, the glycol raw material may be used in excess with respect to the dicarboxylic acid raw material. It is desirable to synthesize such that the carboxyl group end is less than 50 eq / 10 ⁶ g in the copolyester. When it is 50 eq / 10 ⁶ g or more, the number of inactive terminals in the reaction with the diisocyanate compound becomes too large when synthesizing the urethane acrylate resin described later, the desired urethane resin cannot be obtained, and the curability to active energy rays decreases. To do.

The polyester polyol used in the present invention contains 40 mol% or more of an aromatic dicarboxylic acid as a dicarboxylic acid component and has a molecular weight of 1,000 to 10,000. If the aromatic dicarboxylic acid component is less than 40 mol% as the dicarboxylic acid component, the adhesion is lowered and the toughness of the cured coating film is also lowered, which is not preferable. Further, if the molecular weight is less than 1000, the adhesiveness is reduced and the flexibility of the cured coating film is insufficient. If the molecular weight exceeds 10,000, the urethane-forming reactivity decreases and the viscosity increases, which causes a handling problem.

The (2) polyisocyanate compound used in the present invention is 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, p-phenylene diisocyanate, biphenylmethane diisocyanate,
m-phenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,
3'-dimethoxy-4,4'-biphenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,
3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-diphenylene diisocyanate, 4,
4'-diisocyanate diphenyl ether, 1,5 '
-Naphthalene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 1,3
-Diisocyanate compounds such as diisocyanate methylcyclohexane, 1,4-diisocyanate dicyclohexane, 4,4'-diisocyanate dicyclohexane, 4,4'-diisocyanate dicyclohexylmethane and isophorone diisocyanate, or 7 mol% or less of all isocyanate groups of 2 , 4-Tolylene diisocyanate trimer, hexamethylene diisocyanate 3
Triisocyanate compounds such as monomers may be mentioned. Of these isocyanate compounds, isophorone diisocyanate and hexamethylene diisocyanate are particularly preferable in terms of weather resistance.

The compound (3) having at least one (meth) acryloyloxy group and at least one hydrogen group used in the present invention is a mono (meth) glycol such as ethylene glycol, diethylene glycol or hexamethylene glycol. ) Acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, trimethylolpropane, glycerin, monomethyl triol compounds such as trimethylolethane ( Mono (meth) acrylates of tetravalent or higher valent polyols such as (meth) acrylate and di (meth) acrylate, pentaerythritol, dipentaerythritol,
Di (meth) acrylate, tri (meth) acrylate,
Examples thereof include hydroxyl group-containing acrylic compounds such as glycerin monoallyl ether and glycerin diacryl ether.

Urethane acrylate used in the present invention
(A) may optionally contain a polyol other than (1) and /
Alternatively, polyamines may be used as chain extenders. Examples of the polyol other than the above (1) include glycol components of the above (1) copolymerized polyester polyol such as ethylene glycol and propylene glycol. Examples of polyamines include hexamethylenediamine, diaminodiphenylmethane, N-methyldiethanolamine, and high molecular weight polyamines such as terminal aminated polybutadiene having two or more primary or secondary amino groups in the molecule. Further, water may be used similarly to these compounds.

The urethane acrylate (A) of the present invention is prepared by reacting the above-mentioned (1) copolymerized polyester polyol and (2) polyisocyanate compound at [NCO] / [OH] <2 to obtain an isocyanate-terminated urethane prepolymer. Then (3) one or more (meth) acryloyloxy groups and 1
It can be obtained by reacting a compound having at least one hydrogen group. As another production method, the above (1) copolymerized polyester polyol and (2) polyisocyanate compound are used in [NC
O] / [OH] ≧ 2 to obtain an isocyanate-terminated prepolymer, and then (3) a compound having at least one (meth) acryloyloxy group and at least one hydrogen group.
(4) It can be obtained by reacting a polyol and / or a polyamine other than the above (1). These resins can also be obtained by a method in which the compounds to be reacted are collectively charged at a fixed ratio and reacted.

The urethane acrylate (A) of the present invention thus obtained has a molecular weight in the range of 1,000 to 20,000, the number of repeating units of the component (1) is 2 or more in the molecule, and the number of repeating units of the component (1) is at least one. It is necessary to have 3 to 11 urethane bonding groups and / or urea bonding groups per structural unit. When the molecular weight is less than 1000, the strain during curing becomes large, and the adhesion to the substrate becomes poor, which is not preferable. If the molecular weight exceeds 20,000, the compatibility with the polymerizable monomer (B) described later becomes poor, resulting in a problem that the viscosity becomes too high and it becomes difficult to use. When the number of repeating units is one, the toughness and adhesion of the coating film are insufficient. Even if the number of repeating units is 2 or more, if the number of urethane bonding groups and / or urea bonding groups in the molecule is less than 3 per unit of the constituent polyester polyol (1), the adhesion to the substrate will be insufficient. In addition, the toughness of the coating film is insufficient. If it exceeds 11, the adhesiveness will decrease and the viscosity will increase due to urethane bonds and the like, which is not preferable.

Another essential component of the present invention has a molecular weight of 50.
Examples of the polymerizable monomer (B) of less than 0 include (meth)
Methyl acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate,
Phenoxyethyl (meth) acrylate, toluyloxyethyl (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, glycidyl (meth) acrylate , N, N-diethylaminoethyl (meth) acrylate, isobornyl (meth) acrylate, morpholinoethyl acrylate, ethylene oxide modified phosphoric acid (meth) acrylate, N-methylvinylpyrrolidone,
Caprolactone-modified tetrahydrofurfuryl (meth) acrylate, (meth) acryloxyethyl succinate, 2-hydroxy-3-phenoxypropyl (meth)
Monoacrylate compounds such as acrylate, ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, diethylene glycol (meth) acrylate, tripropylene glycol di (meth) acrylate, Hydroxypivalic acid neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, bisphenol A di (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) ) Acrylate, diacrylate compounds such as polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Tri (meth) acrylate,
Triacrylate compounds such as propylene oxide-modified trimethylolpropane triacrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, tetraacrylate compounds such as propionic acid-modified dipentaerythritol tetra (meth) acrylate, dimethylacrylamide , Isopropyl acrylamide, acryloyl morpholine, dimethylaminopropyl acrylamide and the like.

Among these polymerizable monomers, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, toluyloxyethyl (meth) acrylate, N-vinylpyrrolidone, (meth) are preferred because of their excellent adhesion to polyethylene terephthalate. Acryloyl monophorine is preferred.

The pigment (C) used in the present invention may be inorganic or organic. Examples of inorganic pigments include titanium oxide and carbon black, and examples of organic pigments include phthalocyanine blue, quinacridone red, dioxadio violet, isoindoline yellow, and perylene maroon.

The active energy ray-curable coating composition using these compounds is excellent in curability against active energy rays, adhesion to metals and plastics, especially polyethylene terephthalate, and flexibility sufficient for practical use.
It is preferable because it has excellent weather resistance and water resistance.

The active energy ray-curable coating composition according to the present invention comprises the above-mentioned urethane acrylate resin (A), polymerizable monomer (B) and, if necessary, pigment (C). The blending ratio can be set arbitrarily, but in terms of weight ratio
The range of (A) / (B) / (C) = 20 to 50/10 to 50/0 to 55 is preferable. When the content of the component (A) is less than 20% by weight, the properties as a urethane acrylate resin are lost and the adhesion to metals and plastics is deteriorated, and the flexibility, weather resistance and water resistance are deteriorated, which is not preferable. Also the ingredients
When the content of (A) is more than 50% by weight, the viscosity becomes too high to make it difficult to use, and not only the surface smoothness is deteriorated but also the curability to active energy rays is deteriorated, which is not preferable.

As a method for producing the active energy ray-curable coating composition of the present invention, a polymerizable monomer is prepared after the urethane acrylate resin (A) is synthesized by the above method.
There is a method of blending (B). Another method is to synthesize the urethane acrylate resin (A) using the polymerizable monomer (B) as a reaction solvent. As a method of blending the pigment (C), it is preferable to add the pigment (C) to the urethane acrylate resin (A) and disperse it, but the method is not limited to this method.

Components other than the above-mentioned components (A) to (C) can be added to the active energy curable coating material according to the present invention as required. The components that can be added are not particularly limited as long as they are used in ordinary paints. For example, other resins, plasticizers, defoamers, leveling agents, solvents, stabilizers,
There are photopolymerization initiators and the like. The active energy rays used in the present invention are ultraviolet rays, electron rays, γ rays, neutron rays and the like. When ultraviolet rays are used, it is desirable to add a photopolymerization initiator.

The organic solvent usable in the present invention is limited to volatile ones, and most or all of them must be volatilized by heating and drying before curing with active energy rays. Examples of usable solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, esters such as methyl acetate and ethyl acetate, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, benzene, toluene, xylene, and the like. , Aromatic hydrocarbons such as hexane and heptane, alcohols such as methanol, ethanol and isopropyl alcohol, and mixtures thereof. The solvent used during the synthesis of the urethane acrylate resin (A) of the present invention can be used as it is.

As the photopolymerization initiator, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1
-(4-Isopropylphenyl) -2-hydroxy-2
-Methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl)
Acetophenones such as ketones, 1-hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl Benzoin ethers such as ether, benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-
Benzoyl-4′-methyl-diphenyl sulfide,
Alkylated benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4-benzoyl-N, N-dimethyl-N- [2-
((1-Oxo-2-propenyloxy) ethyl] benzenemethanaminium bromide, benzophenones such as (4-benzoylbenzyl) trimethylammonium choroid, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl Examples thereof include thioxanthones such as thioxanthone and 2,4-dichlorothioxanthone, which may be used alone or in combination.

Further, as the photopolymerization initiator, triethanolamine, methyldiethanolamine, triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, benzoic acid (2 -Dimethylamino) ethyl,
4,4'-Dimethylaminobenzophenone, 4,4'-
A sensitizer such as diethylaminobenzophenone may be used in combination.

As an electron beam irradiator, a scanning system,
Or the curtain beam method can be adopted, and the absorbed dose is 1
-20 Mrad, preferably 2-15 Mrad.

The active energy ray-curable coating composition of the present invention has excellent curability with respect to active energy rays, adhesion to metals and plastics, surface smoothness, flexibility, weather resistance and water resistance. Utilizing its characteristics, it can be used in various applications such as surface protection film for metals and plastics, coating of electronic parts, top coating agent for furniture, anticorrosion coating of steel materials, surface coating agent for optical fiber, surface treatment of printing paper, etc. .

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by weight".

(Production Example of Copolyester Polyol) Dimethyl terephthalate 44 was placed in a reaction vessel equipped with a thermometer, a stirrer, a distillation column, a condenser, and a pressure reducing device.
0 part, 440 parts of dimethyl isophthalate, 412 parts of ethylene glycol, 393 parts of hexanediol, and 0.5 parts of tetrabutoxy titanate were charged, and 150 to 23
A transesterification reaction was performed by heating at 0 ° C for 120 minutes.
Then, the reaction system was depressurized to 10 mmHg and the temperature was raised to 250 ° C. for 30 minutes to carry out the reaction to obtain a copolymerized polyester polyol A. Polyester polyol A has a molecular weight of 160
It was 0. The polyester polyols B to F obtained by the same method are shown in Table 1 together with the polyester polyol A. The resin composition was analyzed by ¹ H NMR.

[0029]

[Table 1]

(Production Example 1 of active energy ray-curable coating composition) 100 parts of copolymerized polyester polyol A and 132 parts of phenoxyethyl acrylate were charged into a reaction vessel equipped with a thermometer, a stirrer and a reflux condenser, and after dissolution. , 17 parts of hexamethylene diisocyanate and 0.05 part of dibutyltin dilaurate were charged and reacted at 70 to 80 ° C. for 2 hours, and then 15 parts of 2-hydroxyethyl acrylate was further added to carry out the reaction at 70 to 80 ° C. To obtain an active energy ray-curable coating composition A which is a phenoxyethyl acrylate solution of a urethane acrylate resin. The molecular weight of urethane acrylate is 2
It was 000. Urethane acrylate resins were synthesized by the same method to obtain active energy ray-curable coating compositions B to E. The composition obtained is shown in Table 2.

[0031]

[Table 2]

(Production Example 2 of active energy ray-curable coating composition) 100 parts of copolymerized polyester polyol A and 135 parts of acryloylmorpholine were charged into a reaction vessel equipped with a thermometer, a stirrer and a reflux condenser, and after dissolution, After charging 21 parts of hexamethylene diisocyanate and 0.05 parts of dibutyltin dilaurate and reacting at 70 to 80 ° C. for 2 hours, 7 parts of 2-hydroxyethyl acrylate was further added and further reacted at 70 to 80 ° C. for 2 hours, By adding 7 parts of 3-methyl-1,5-pentanediol as a chain extender and carrying out the reaction, an active energy ray-curable coating composition F, which is a solution of urethane acrylate resin in acryloylmorpholine, was obtained. The molecular weight of urethane acrylate was 4,100. Urethane acrylate resins were synthesized by the same method to obtain active energy ray-curable coating compositions G to K. The composition obtained is the third
Shown in the table.

[0033]

[Table 3]

Example 1 A photopolymerization initiator 1- (4-isopropylphenyl) -2 was added to 100 parts of the active energy ray-curable coating composition B.
-Hydroxy-2-methylpropan-1-one (manufactured by Darocur 1116 MARK) was mixed, and the thickness after curing was 10 μm on a polyethylene terephthalate sheet.
It was applied using an applicator so as to have m. Then, 6.4kw x 4 lamps water-cooled low-pressure mercury lamp is used to emit 100 ultraviolet rays.
Polymerization was performed by irradiating so as to obtain mJ / cm ² . A coating film was formed on a galvanized steel sheet, a polycarbonate sheet, a polyimide sheet, and a vinyl chloride sheet by the same method. Coating films were similarly prepared for coating compositions C, E, F and H.

Comparative Example 1 Photopolymerization initiator 1- (4-isopropylphenyl) -2 was added to 100 parts of active energy ray-curable coating composition A.
-Hydroxy-2-methylpropan-1-one (manufactured by Darocur 1116 MARK) was mixed, and the thickness after curing was 10 μm on a polyethylene terephthalate sheet.
It was applied using an applicator so as to have m. Then, 6.4kw x 4 lamps water-cooled low-pressure mercury lamp is used to emit 100 ultraviolet rays.
Polymerization was performed by irradiating so as to obtain mJ / cm ² . A coating film was formed on a galvanized steel sheet, a polycarbonate sheet, a polyimide sheet, and a vinyl chloride sheet by the same method. Coating films were similarly prepared for the coating compositions D, G, I, J, and K.

The coating film was evaluated by the following method.・ Adhesiveness Using a ruler for cross-cutting test of Taiki Equipment Co., Ltd., 100 pieces of 1 mm x 1 mm squares were made on the coating film with a cutter knife. Nichiban Co., Ltd. cellophane tape No. 405 was attached and peeled off, and the number of crosses in which the coating film was adhered without peeling off was evaluated.

Surface smoothness The surface condition of the coating film was visually evaluated. ◯: Good smoothness Δ: Slightly decreased smoothness ×: Poor smoothness

-Flexibility: Using a paint film bending tester manufactured by Taiyo Equipment Co., Ltd., bend the coating film together with the substrate by 180 °. At this time, the diameter of the minimum mandrel that does not cause cracks or peeling on the painted surface is used.

-Weather resistance In the accelerated weather resistance test (QUV), the change in gloss after 300 hours of exposure was visually judged. ◯: No abnormality Δ: Gloss slightly decreased X: Gloss significantly decreased

Water resistance The change in gloss of the coating surface after the coating film was left in water for 300 hours was visually evaluated. ◯: No abnormality Δ: Gloss slightly decreased X: Gloss significantly decreased

Tables 4 and 5 show the evaluation results of the coating films obtained from the active energy ray-curable coating compositions of Example 1 and Comparative Example 1.

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

The active energy ray-curable coating composition of the present invention has excellent curability with respect to active energy rays, and the cured film has adhesion to metals and plastics, surface smoothness, flexibility and weather resistance. , Which is excellent in water resistance.

Claims (1)

[Claims] 1. The number of repeating units of the component (1) obtained by reacting with the following (1) to (3) is 2 or more and the component (1):
Having a molecular weight of 3 to 11 urethane bond groups and / or urea bond groups per unit of 1000 to 2000
No. 0 urethane acrylate (A), polymerizable monomer (B) having a molecular weight of less than 500, and optionally pigment (C), active energy ray-curable coating composition (1) Aromatic Copolyester polyol containing dicarboxylic acid in an amount of 40 mol% or more and having a molecular weight of 1,000 to 10,000 (2) Polyisocyanate compound (3) Compound having one or more (meth) acryloyloxy groups and one or more hydrogen groups .