Active energy ray-curable coating composition for flooring, cured coating film, and substrate with cured coating film

Abstract

Provided is an active energy ray-curable coating composition capable of forming a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance. The active energy ray-curable coating composition contains a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and particles (D). (A): Contains a trifunctional urethane (meth)acrylate (a1) and a hexafunctional urethane (meth)acrylate (a2), and the content of (A) is 20% by mass or more and 60% by mass or less relative to 100% by mass of the solid content of the composition. (B): Contains at least a (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups. (D): Contains inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3), and the content of (D) is 5% by mass or more and 30% by mass or less relative to 100% by mass of the solid content of the composition.

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable coating composition for flooring. The present invention also relates to a cured coating film formed from the active energy ray-curable coating composition and a substrate having the cured coating film. [Background technology]

[0002] Conventionally, a cured coating film has been provided on the surface of a flooring substrate, and various properties such as stain resistance and abrasion resistance are required of this cured coating film.

[0003] For example, in order to improve contamination resistance, warpage resistance, and abrasion resistance, Patent Document 1 proposes an energy ray-curable resin composition for flooring materials, which is characterized by containing a bifunctional urethane (meth)acrylate resin (A), a polysiloxane-modified urethane (meth)acrylate resin (B), and an epoxy (meth)acrylate resin (C). Furthermore, in order to improve contamination resistance, Patent Document 2 proposes an active energy ray-curable resin composition containing (A) urethane acrylate particles and (B) an active energy ray-curable resin, in which the content of the (A) urethane acrylate particles is 1% by mass or more and 60% by mass or less, based on 100% by mass of the solid content of the composition. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-57297 [Patent Document 2] Patent Publication No. 2021-20994 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the cracking resistance of the cured coating film was not fully investigated in Patent Documents 1 and 2. Therefore, there is a need for the development of a cured coating film that is excellent in all of cracking resistance, stain resistance, and abrasion resistance.

[0006] Therefore, an object of the present invention is to provide an active energy ray-curable coating composition capable of forming a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance. Another object of the present invention is to provide a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by providing an active energy ray-curable coating composition for flooring materials containing a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and particles (D), wherein the urethane (meth)acrylate (A) contains a trifunctional urethane (meth)acrylate (a1) and a hexafunctional urethane (meth)acrylate (a2), the (meth)acrylate monomer (B) contains at least a (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups, and the particles (D) contain inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3), and further adjusting the content of specific components. The present invention was completed based on this finding.

[0008] That is, according to the present invention, the following inventions are provided. [1] An active energy ray-curable coating composition for flooring materials, comprising a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and particles (D), the urethane (meth)acrylate (A) contains a trifunctional urethane (meth)acrylate (a1) and a hexafunctional urethane (meth)acrylate (a2); the content of the urethane (meth)acrylate (A) is 20% by mass or more and 60% by mass or less, based on 100% by mass of the solid content of the active energy ray-curable coating composition; the total content of the trifunctional urethane (meth)acrylate (a1) and the hexafunctional urethane (meth)acrylate (a2) is 70% by mass or more, based on the total amount of the urethane (meth)acrylate (A); the (meth)acrylate monomer (B) contains at least a (meth)acrylate monomer (b1) having a functional group number of 3 or more and 4 or less, the particles (D) include inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3); an active energy ray-curable coating composition for flooring, wherein the content of the particles (D) is 5% by mass or more and 30% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable coating composition, and the content of the urethane resin particles (d2) is 15% by mass or more and 50% by mass or less, relative to the total amount of the particles (D). [2] The active energy ray-curable coating composition according to [1], wherein the content of the trifunctional urethane (meth)acrylate (a1) is 20% by mass or more and 80% by mass or less based on the total of the trifunctional urethane (meth)acrylate (a1) and the hexafunctional urethane (meth)acrylate (a2). [3] The active energy ray-curable coating composition according to [1] or [2], wherein the content of the (meth)acrylate monomer (B) is 20% by mass or more and 60% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable coating composition. [4] The active energy ray-curable coating composition according to any one of [1] to [3], wherein the content of the (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups is 20% by mass or more and 60% by mass or less based on the total amount of the (meth)acrylate monomer (B). [5] The active energy ray-curable coating composition according to any one of [1] to [4], wherein the content of the inorganic particles (d1) is 20% by mass or more and 70% by mass or less based on the total amount of the particles (D). [6] The active energy ray-curable resin coating composition according to any one of [1] to [5], wherein the content of the acrylic resin particles (d3) is 5% by mass or more and 40% by mass or less relative to the total amount of the particles (D). [7] The active energy ray-curable coating composition according to any one of [1] to [6], wherein the flooring material is made of a synthetic resin. [8] A cured coating film formed from the active energy ray-curable coating composition according to any one of [1] to [7]. [9] A substrate having a cured coating film, the substrate having, on at least a part of its surface, a cured coating film formed from the active energy ray-curable coating composition according to any one of [1] to [7].

[10] A step of applying the active energy ray-curable coating composition according to any one of [1] to [7] to at least a part of a surface of a substrate; a curing step of curing the active energy ray-curable coating composition by ultraviolet irradiation to form a cured coating film after the coating step; A method for producing a substrate with a cured coating film, comprising: [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an active energy ray-curable coating composition capable of forming a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance. Furthermore, according to the present invention, it is possible to provide a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance, and a substrate having the cured coating film. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will now be described in more detail. In this specification, "(meth)acrylate" refers to acrylate and methacrylate, and "(meth)acryloyl" refers to acryloyl and methacryloyl. The term "active energy rays" refers to rays including ultraviolet rays, visible light, infrared rays, electron beams, X-rays, gamma rays, proton rays, neutron rays, and the like. The term "solid content" refers to the components remaining after excluding volatile components such as organic solvents from the active energy ray-curable coating composition, and which constitute a cured coating film when cured.

[0011] <Active energy ray curable coating composition> The active energy ray-curable coating composition according to the present invention contains at least a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and particles (D). The active energy ray-curable coating composition according to the present invention is suitable for flooring materials. Such an active energy ray-curable coating composition can form a cured coating film that is excellent in crack resistance, contamination resistance, and abrasion resistance.

[0012] Each component of the active energy ray-curable coating composition according to the present invention will be described in detail below.

[0013] (Urethane (meth)acrylate (A)) The urethane (meth)acrylate (A) is not particularly limited, but for example, a polyfunctional urethane (meth)acrylate, which is a reaction product of an isocyanate compound obtained by reacting a polyol with a diisocyanate, and a (meth)acrylate monomer having a hydroxyl group, can be used. The polyfunctional urethane (meth)acrylate is preferably an oligomer or polymer, and more preferably an oligomer. The polyfunctional urethane (meth)acrylate may also be a modified product obtained by silicone modification, fluorine modification, or the like. The silicone modification, fluorine modification, or the like treatment can be carried out by a conventionally known method and is not particularly limited.

[0014] The number of functional groups in the polyfunctional urethane (meth)acrylate is not particularly limited, but is preferably from 2 to 12, and more preferably from 3 to 6. In the present invention, the active energy ray-curable coating composition preferably contains at least a trifunctional urethane (meth)acrylate (a1) and a hexafunctional urethane (meth)acrylate (a2).

[0015] The polyol, which is a raw material for synthesizing the isocyanate compound, is not particularly limited, but examples thereof include polyester polyol, polyether polyol, polycarbonate polyol, etc., and one of these may be used alone, or two or more may be used in combination.

[0016] There are no particular restrictions on the production method of the polyester polyol, and it is possible to use polyester polyols obtained by known methods, such as by subjecting a diol to a polycondensation reaction with a dicarboxylic acid or a dicarboxylic acid chloride, or by esterifying a diol or a dicarboxylic acid and subjecting it to a transesterification reaction. The diol used in the synthesis of the polyester polyol is not particularly limited, but examples thereof include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, and tetrapropylene glycol. The dicarboxylic acid used in the synthesis of the polyester polyol is not particularly limited, but examples thereof include adipic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, dimaleic acid, terephthalic acid, isophthalic acid, and phthalic acid.

[0017] The polyether polyol is not particularly limited, but examples thereof include polyethylene oxide, polypropylene oxide, and ethylene oxide-propylene oxide random copolymers.

[0018] The polycarbonate polyol is not particularly limited, but examples thereof include reaction products obtained by polycondensation of the following components A and B. That is, component A is not particularly limited, but examples thereof include diols such as 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol, dipropylene glycol, and diethylene glycol, or reaction products of these diols with dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, and hexahydrophthalic acid. Component B is not particularly limited, but examples thereof include aromatic carbonates or aliphatic carbonates such as diphenyl carbonate, bis(chlorophenyl) carbonate, dinaphthyl carbonate, phenyltoluyl carbonate, phenylchlorophenyl carbonate, 2-tolyl-4-tolyl carbonate, dimethyl carbonate, diethyl carbonate, diethylene carbonate, and ethylene carbonate.

[0019] The diisocyanate that is a raw material for synthesizing the isocyanate compound is not particularly limited, but a linear or cyclic aliphatic diisocyanate is preferred. Specific examples include isocyanate group-containing linear hydrocarbons such as tetramethylene diisocyanate and hexamethylene diisocyanate; isocyanate group-containing branched hydrocarbons such as 2,2,4-trimethylhexamethylene diisocyanate; isocyanate group-containing cyclic hydrocarbons such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate and hydrogenated toluene diisocyanate; and diisocyanate group-containing aromatic hydrocarbons such as p-phenylene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 1,3-xylene diisocyanate, dianisidine diisocyanate, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, tolylene diisocyanate and 4,4-diphenylmethane diisocyanate.

[0020] As the (meth)acrylate monomer having a hydroxyl group, a (meth)acrylate having at least one hydroxyl group, preferably 1 to 5 hydroxyl groups, can be used. Furthermore, the number of carbon atoms in such a hydroxyl group-containing (meth)acrylate is not particularly limited, but it is preferable that it has a hydrocarbon moiety having 2 to 20 carbon atoms. Here, the hydrocarbon moiety refers to an organic group having a linear or branched aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, and the aliphatic hydrocarbon group or alicyclic hydrocarbon group may be saturated or unsaturated. Furthermore, a portion of the hydrocarbon moiety may contain an ether bond (C-O-C bond).

[0021] Examples of (meth)acrylate monomers having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, hydroxyhexyl (meth)acrylate, 3-hydroxy-3-chloropropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycidol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, and dipentaerythritol di(meth)acrylate. In addition to the above, modified products such as polycaprolactone-modified 2-hydroxyethyl (meth)acrylate may also be used.

[0022] As the polyfunctional urethane (meth)acrylate, commercially available products can also be used. Examples of bifunctional urethane (meth)acrylates include UV-841, UV-71, UV-72, UV-73, UV-820, UV-822, and UV-831 (all manufactured by Ohtake Meishin Chemical Co., Ltd.), MIRAMER SC2565 (MIWON SPECIALTY Examples of suitable resins include: EBECRYL210, EBECRYL215, EBECRYL230, EBECRYL244, EBECRYL245, EBECRYL270, EBECRYL284, EBECRYL285, EBECRYL8402, and EBECRYL9270 (manufactured by Daicel-Allnex Co., Ltd.); Shikoh UV-3310B, Shikoh UV-6630B, and Shikoh UV-6640B (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.); UA-122P, U-200PA, and UA-4200 (manufactured by Shin-Nakamura Chemical Co., Ltd.); and Art Resin UN-333, Art Resin UN-2600, Art Resin UN-2700, and Art Resin UN-9000PEP (manufactured by Negami Chemical Industrial Co., Ltd.). Examples of the trifunctional urethane (meth)acrylate (a1) include trade names UV-55, UV-51, UV-55E, and UV-56 (manufactured by Ohtake Meishin Chemical Co., Ltd.), and trade names EBECRYL 4738, EBECRYL 4740, and EBECRYL 4513 (manufactured by Daicel-Allnex Co., Ltd.). Examples of tetrafunctional urethane (meth)acrylates include trade names: EBECRYL 8210, EBECRYL 8405, and KRM8528 (manufactured by Daicel Allnex Co., Ltd.). Examples of pentafunctional urethane (meth)acrylates include DM850 (manufactured by DOUBLE BOND CHEMICAL Co., Ltd.) and HITALOID 7903-1 (manufactured by Hitachi Chemical Co., Ltd.). Examples of the hexafunctional urethane (meth)acrylate (a2) include trade names: MIRAMER PU5000 (manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd.), MIRAMER PU610 (manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd.), Art Resin UN-CMP-1 (manufactured by Negami Chemical Industrial Co., Ltd.), trade names: EBECRYL 1290k, EBECRYL 5129, EBECRYL 220 (all manufactured by Daicel-Allnex Co., Ltd.), trade names: U-6LPA, UA-1100H (all manufactured by Shin-Nakamura Chemical Co., Ltd.), trade name: CN975 (manufactured by Sartomer Co., Ltd.), and trade names: DM527, DM528, DM571, DM576, DM776, DM87A, DM88A (all manufactured by DOUBLE BOND Chemical Co., Ltd.), and trade names: Hitaloid 7902-1 and TA24-195H (all manufactured by Hitachi Chemical Co., Ltd.). Examples of the nonafunctional urethane (meth)acrylate include trade names: KRM 7804 and KRM8904 (both manufactured by Daicel Allnex Co., Ltd.), trade names: Hitaloid 7903-3 and Hitaloid 7903-B (both manufactured by Hitachi Chemical Co., Ltd.), and the like. Examples of the 10-functional urethane (meth)acrylate include trade name: KRM8452 (manufactured by Daicel Allnex Co., Ltd.) and trade name: DM588 (manufactured by Double Bond Chemical Co., Ltd.). Examples of the 12-functional urethane (meth)acrylate include DM5812 (manufactured by DOUBLE BOND CHEMICAL Co., Ltd.) and HITALOID 7903-4 (manufactured by Hitachi Chemical Co., Ltd.).

[0023] From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of the urethane (meth)acrylate (A) is 20% by mass or more and 60% by mass or less, more preferably 23% by mass or more, even more preferably 26% by mass or more, still more preferably 29% by mass or more, and more preferably 58% by mass or less, even more preferably 56% by mass or less, and still more preferably 55% by mass or less, relative to 100% by mass of the solids content of the active energy ray-curable coating composition. The total content of the trifunctional urethane (meth)acrylate (a1) and the hexafunctional urethane (meth)acrylate (a2) is 70 mass% or more, preferably 75 mass% or more, more preferably 80 mass% or more, even more preferably 85 mass% or more, and may be 100 mass% based on the total amount of the urethane (meth)acrylate (A).

[0024] ((Meth)acrylate Monomer (B)) The (meth)acrylate monomer (B) has one or more (meth)acryloyl groups as functional groups in the molecule. The number of functional groups in the (meth)acrylate monomer is not particularly limited, but is, for example, 1 to 6, and preferably 1 to 4. In the present invention, the active energy ray-curable coating composition preferably contains at least a (meth)acrylate monomer (b1) having 3 to 4 functional groups, and may further contain at least one of a monofunctional (meth)acrylate monomer and a bifunctional (meth)acrylate monomer.

[0025] Examples of the (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups include glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, EO-added trimethylolpropane tri(meth)acrylate, PO-added trimethylolpropane tri(meth)acrylate (PO portion n=2), PO ... Examples of such (meth)acrylate monomers include glycerin PO-added tri(meth)acrylate, 2-(meth)acryloyloxypropyl tetrahydrohydrogen terephthalate, PO-added glycol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, EO-added pentaerythritol tri(meth)acrylate, tris((meth)acryloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol tetra(meth)acrylate. These (meth)acrylate monomers having 3 or more and 4 or less functional groups may be used alone or in combination of two or more.

[0026] Examples of monofunctional (meth)acrylate monomers include aliphatic short-chain alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and tert-butyl (meth)acrylate; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, pentaerythritol mono(meth)acrylate, and ethyl carbitol (meth)acrylate; Examples of the monofunctional (meth)acrylate monomer include alkoxy group-containing (meth)acrylates such as methyl (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxytetraethylene glycol (meth)acrylate; amino group-containing (meth)acrylates such as 2-(N,N-dimethylamino)ethyl (meth)acrylate; (meth)acrylates having a heterocyclic structure such as tetrahydrofurfuryl (meth)acrylate; polycyclic (meth)acrylates such as dicyclopentanyl (meth)acrylate and dicyclopentenyl (meth)acrylate acid; 3,3,5-trimethylcyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, and (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate. These monofunctional (meth)acrylate monomers may be used alone or in combination of two or more.

[0027] Examples of the bifunctional (meth)acrylate monomer include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, and neopentyl glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate; Polyoxyalkylene glycol di(meth)acrylates such as dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; di(meth)acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene glycol di(meth)acrylate; trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, (Meth)acrylate, di(meth)acrylates of aliphatic polyols such as pentaerythritol di(meth)acrylate; di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkanol such as hydrogenated dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate; di(meth)acrylates of dioxane glycol or dioxane dialkanol such as 1,3-dioxane-2,5-diyl di(meth)acrylate [also known as dioxane glycol di(meth)acrylate]; bisphene Di(meth)acrylates of alkylene oxide adducts of bisphenol A or bisphenol F, such as bisphenol A ethylene oxide adduct diacrylate and bisphenol F ethylene oxide adduct diacrylate; epoxy di(meth)acrylates of bisphenol A or bisphenol F, such as acrylic acid adduct of bisphenol A diglycidyl ether and acrylic acid adduct of bisphenol F diglycidyl ether; silicone di(meth)acrylates; di(meth)acrylate of hydroxypivalic acid neopentyl glycol ester;Examples of suitable difunctional (meth)acrylate monomers include 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane, di(meth)acrylate of 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane, and tris(hydroxyethyl)isocyanurate di(meth)acrylate. These difunctional (meth)acrylate monomers may be used alone or in combination of two or more.

[0028] From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of the (meth)acrylate monomer (B) is preferably 20% by mass or more and 60% by mass or less, more preferably 23% by mass or more, even more preferably 25% by mass or more, still more preferably 28% by mass or more, and more preferably 55% by mass or less, even more preferably 50% by mass or less, and still more preferably 45% by mass or less, relative to 100% by mass of the solids content of the active energy ray-curable coating composition. From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of the (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups is preferably 20% by mass or more and 60% by mass or less, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 50% by mass or more, and more preferably 59% by mass or less, even more preferably 58% by mass or less, and still more preferably 57% by mass or less, relative to the total amount of the (meth)acrylate monomer (B).

[0029] (Photopolymerization initiator (C)) The photopolymerization initiator (C) is not particularly limited, and any conventionally known photopolymerization initiator for ultraviolet curing can be used. Examples of the photopolymerization initiator include acylphosphine oxide-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoyl formate-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, oxime ester-based photopolymerization initiators, hydroxybenzoyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, α-aminoalkylphenone-based photopolymerization initiators, and other photopolymerization initiators.

[0030] Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Examples of the acetophenone-based photopolymerization initiator include acetophenone, 3-methylacetophenone, benzyl dimethyl ketal, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one. Examples of the benzoyl formate-based photopolymerization initiator include methyl benzoyl formate. Examples of the thioxanthone-based photopolymerization initiator include isopropyl thioxanthone. Examples of the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime). Examples of the hydroxybenzoyl-based photopolymerization initiator include benzoin alkyl ether. Examples of the benzophenone-based photopolymerization initiator include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone. Examples of α-aminoalkylphenone photopolymerization initiators include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-(N,N- dimethylamino)-1-(4-morpholinophenyl)butan-1-one, and the like. Other photopolymerization initiators that can be used include bis(2-phenyl-2-oxoacetic acid)oxybisethylene. These photopolymerization initiators may be used alone or in combination of two or more.

[0031] From the viewpoint of the curability of the cured coating film, the content of the photopolymerization initiator (C) is preferably 1.0 mass % or more and 30.0 mass % or less, more preferably 1.5 mass % or more and 20.0 mass % or less, and even more preferably 2.0 mass % or more and 10.0 mass % or less, relative to 100 mass % of the solids content of the active energy ray-curable coating composition.

[0032] (Particle (D)) The particles (D) include inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3). In the present invention, the active energy ray-curable coating composition contains all three types of particles, i.e., inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3), and thus the crack resistance, contamination resistance, and abrasion resistance of the cured coating film can be improved.

[0033] (Inorganic particles (d1)) Examples of inorganic particles (d1) include silica, aluminosilicate, alumina, mica, zeolite, diatomaceous earth, graphite, clay, talc, and feldspar. Among these, silica and aluminosilicate are preferred. These inorganic particles may be used alone or in combination of two or more.

[0034] (Urethane resin particles (d2)) The urethane resin particles (d2) are not particularly limited as long as they are made of a urethane resin, and conventionally known urethane resins can be used. Crosslinked urethane resins can also be used. Urethane resins can be produced by widely known methods, such as a method of directly reacting a polyol component with an isocyanate component in a dispersion medium such as water, or a method of reacting a polyol component with an isocyanate component to obtain a terminal isocyanate prepolymer and then reacting the resulting prepolymer in water. The urethane resin particles (d2) may be used alone or in combination of two or more types. The urethane resin particles (d2) do not include urethane acrylate resin particles. The urethane acrylate particles are resin particles obtained from a resin composition containing a urethane component and a (meth)acrylate component, and / or a urethane acrylate.

[0035] (Acrylic resin particles (d3)) The acrylic resin particles (d3) are not particularly limited as long as they are particles made of an acrylic resin, and any conventionally known acrylic resin can be used. The acrylic resin particles (d3) may be used alone or in combination of two or more.

[0036] The method for producing the acrylic resin particles (d3) is not particularly limited, and they can be obtained by reacting a polymerizable unsaturated monomer by a polymerization method known per se, such as suspension polymerization, solution polymerization, emulsion polymerization, bulk polymerization, etc. Among these polymerization methods, suspension polymerization is particularly preferred. Examples of the polymerizable unsaturated monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, octadecyl (meth)acrylate, and isostearyl (meth)acrylate. alkyl (meth)acrylates having 1 to 24 carbon atoms, such as styrene, vinyl acetate; acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile; carboxyl group-containing monomers, such as maleic acid, maleic anhydride, crotonic acid, and itaconic acid; nitrogen-containing alkyl (meth)acrylates, such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and Nt-butylaminoethyl (meth)acrylate; acrylamide, methacrylamide, and N-methyl (meth)acrylate Examples of the polymerizable monomer include polymerizable amides such as 2-vinylpyridine, 1-vinyl-2-pyrrolidone, 4-vinylpyridine, and allylamine; monoesters of polyhydric alcohols with acrylic acid or methacrylic acid, such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2,3-dihydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and polyethylene glycol mono(meth)acrylate; hydroxyl group-containing monomers such as compounds obtained by ring-opening polymerization of the monoesters of the above polyhydric alcohols with acrylic acid or methacrylic acid with ε-caprolactone; and monomers having two or more polymerizable unsaturated groups in one molecule. These polymerizable unsaturated monomers may be used alone or in combination of two or more. The acrylic resin particles (d3) do not include the urethane acrylate particles.

[0037] The average particle diameter (D 50 ) is not particularly limited, but is preferably 1 μm or more and 50 μm or less, more preferably 2 μm or more, even more preferably 3 μm or more, even more preferably 4 μm or more, and more preferably 40 μm or less, even more preferably 30 μm or less, and even more preferably 25 μm or less. 50 ) is within the above range, the cured coating film formed from the active energy ray-curable coating composition will have excellent crack resistance, contamination resistance, and abrasion resistance. The average particle diameter (D 50 ) is a value measured by a laser diffraction / scattering method, and can be measured, for example, using a laser diffraction / scattering particle size distribution measuring device "Microtrac MT3000II" (manufactured by Microtrac Bell).

[0038] From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of particles (D) is 5% by mass or more and 30% by mass or less, preferably 7% by mass or more, more preferably 9% by mass or more, even more preferably 11% by mass or more, and preferably 28% by mass or less, more preferably 26% by mass or less, even more preferably 24% by mass or less, relative to 100% by mass of the solids content of the active energy ray-curable coating composition. From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of inorganic particles (d1) is preferably 20% by mass or more and 70% by mass or less, more preferably 23% by mass or more, even more preferably 26% by mass or more, still more preferably 29% by mass or more, and more preferably 67% by mass or less, even more preferably 64% by mass or less, and still more preferably 61% by mass or less, relative to the total amount of particles (D). From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of the urethane resin particles (d2) is 15% by mass or more and 50% by mass or less, preferably 20% by mass or more, more preferably 23% by mass or more, and preferably 48% by mass or less, more preferably 46% by mass or less, and even more preferably 44% by mass or less, relative to the total amount of the particles (D). From the viewpoint of the cracking resistance, contamination resistance, and abrasion resistance of the cured coating film, the content of the acrylic resin particles (d3) is preferably 5% by mass or more and 40% by mass or less, more preferably 7% by mass or more, even more preferably 9% by mass or more, still more preferably 11% by mass or more, and more preferably 38% by mass or less, even more preferably 36% by mass or less, and still more preferably 34% by mass or less, relative to the total amount of the particles (D).

[0039] (Other ingredients) In addition to the above-mentioned components, the active energy ray-curable coating composition according to the present invention may further contain, as necessary, polymerization inhibitors, leveling agents, dispersants, antifoaming agents, adhesion-imparting agents, non-reactive diluents, anti-settling agents, heat stabilizers, ultraviolet absorbers, light stabilizers, antifouling improvers, photosensitizers, antistatic agents, scratch-resistant agents, antifungal agents, antiviral agents, antibacterial agents, deodorizers, silane coupling agents, plasticizers, and the like, within a range that does not impair the object of the present invention.

[0040] The active energy ray-curable coating composition according to this embodiment may be either a solvent-based coating composition that is diluted with an organic solvent (non-reactive diluent) such as thinner or alcohol, or a solventless coating composition that does not require dilution with an organic solvent. However, a solventless coating composition is preferred because it leaves no residual volatile organic compounds (VOCs), has no effect on the human body, and is environmentally friendly.

[0041] (Method for preparing active energy ray-curable coating composition) The active energy ray-curable coating composition of the present invention can be obtained by mixing and stirring the above-mentioned components using a conventionally known device such as a mixer, disperser, stirrer, etc. Examples of such device include a disperser, a mixing / dispersing mill, a mortar mixer, a roll, a paint shaker, a homogenizer, etc.

[0042] [Substrate with cured coating] The substrate with a cured coating film according to the present invention has a cured coating film formed from the above-described active energy ray-curable coating composition on at least a portion of the substrate surface. The cured coating film may be provided on the entire surface of the substrate, or only a portion of the surface, or may be provided on one side of the substrate, or on both sides of the substrate. When provided on a portion of the surface, the form of the cured coating film is not particularly limited, and any form can be adopted without particular limitation, such as a sea-island pattern, a sea part or island part, a lattice pattern, a mosaic pattern, or the like.

[0043] (base material) In the present invention, the use of the substrate is not particularly limited, but it is preferably used as a flooring material. Furthermore, the substrate is preferably made of a synthetic resin. Examples of synthetic resins include thermoplastic resins and thermosetting resins. Specific examples of thermoplastic resins include polyvinyl chloride resins, polyolefin resins, polystyrene resins, polyester resins, and acrylic resins. Specific examples of thermosetting resins include phenolic resins, epoxy resins, urethane resins, urea resins, and melamine resins. The thickness of the substrate is not particularly limited, but is preferably 0.1 mm or more and 50 mm or less, and more preferably 1 mm or more and 20 mm or less.

[0044] (cured coating) The cured coating film is formed from the above-mentioned active energy ray-curable coating composition. The thickness of the cured coating film is not particularly limited, but from the viewpoints of crack resistance, contamination resistance, abrasion resistance, etc., it is preferably 1 μm or more and 200 μm or less, more preferably 3 μm or more and 100 μm or less, and even more preferably 5 μm or more and 50 μm or less. In the present invention, the film thickness refers to the thickness of the cured coating film when the cross section of the cured coating film is observed with an optical microscope, a scanning electron microscope (SEM), or the like. When forming a coating film of such a thickness, the coating film of the desired thickness may be formed by a single coating, or may be formed by multiple coatings.

[0045] <Method of manufacturing a substrate with a cured coating film> The substrate with a cured coating film according to the present invention comprises a step of applying the above-mentioned active energy ray-curable coating composition to at least a part of the surface of the substrate (application step), and a curing step of curing the active energy ray-curable coating composition by ultraviolet irradiation after the application step to form a cured coating film (curing step).

[0046] (coating process) The coating step is a step of applying the active energy ray-curable coating composition to at least a part of the surface of a substrate by a conventionally known method. For example, a coating machine such as a bar coater, a gravure coater, a roll coater (such as a natural roll coater or a reverse roll coater), a curtain flow coater, an air knife coater, a spin coater, a blade coater, an air sprayer, or an airless sprayer can be used for coating. Among these, a coating method using a roll coater is preferred from the viewpoints of workability and productivity.

[0047] The coating film thickness after curing and drying is preferably in the range of the above-mentioned thickness of the cured coating film.

[0048] When the active energy ray-curable coating composition is used after diluting with a solvent, it is preferable to dry it after application. Drying methods include, for example, hot air drying (dryer, etc.). The drying temperature is preferably 10 to 200°C, with a more preferred upper limit of 150°C from the viewpoint of the smoothness and appearance of the coating film, and a more preferred lower limit of 30°C from the viewpoint of drying speed.

[0049] (hardening process) The curing step is a step of curing the active energy ray-curable coating composition by irradiation with ultraviolet rays to form a cured coating film. Examples of active energy rays include ultraviolet rays (far ultraviolet rays, near ultraviolet rays, etc.), infrared rays, and electron beams. Among them, ultraviolet rays are preferred in terms of curing speed, availability of irradiation equipment, cost, etc.

[0050] Examples of the method of curing with ultraviolet light include a method of irradiating ultraviolet light using a high-pressure mercury lamp, metal halide lamp, xenon lamp, chemical lamp, UV-LED, or the like that emits light in the wavelength range of 200 to 500 nm. From the viewpoint of the curability of the active energy ray-curable coating composition, the ultraviolet light irradiation conditions per time are preferably an integrated light amount of 100 to 3000 mJ / cm. 2 and more preferably 200 to 2500 mJ / cm 2 and the ultraviolet irradiance is preferably 50 to 500 mW / cm 2 and more preferably 60 to 400 mW / cm 2 The step of irradiating with ultraviolet light may be carried out only once, or may be repeated multiple times. [Example]

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0052] First, the following raw materials were prepared for preparing an active energy ray-curable coating composition. (Component (A)) Bifunctional urethane (meth)acrylate 1: Aliphatic (IPDI) urethane (meth)acrylate, manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd., trade name: MIRAMER SC2565 Bifunctional urethane (meth)acrylate 2: Mitsubishi Chemical Corporation, product name: Shikou UV-6640B Trifunctional urethane (meth)acrylate (a1): manufactured by Ohtake Meishin Chemical Co., Ltd., product name: UV-55 Hexafunctional urethane (meth)acrylate 1 (a2): manufactured by Negami Chemical Industrial Co., Ltd., product name: Art Resin UN-CMP-1 Hexafunctional urethane (meth)acrylate 2(a2): MIWON SPECIALTY CHEMICAL Co., Ltd., product name: MIRAMER PU5000 Silicone-modified urethane (meth)acrylate: Polysiloxane-modified urethane (meth)acrylate resin, manufactured by Ohtake Meishin Chemical Co., Ltd., product name: UVS-520A ((B) component) Monofunctional (meth)acrylate monomer: methoxytriethylene glycol acrylate, manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Acrylate MTG-A Bifunctional (meth)acrylate monomer: Tripropylene glycol diacrylate, manufactured by BASF Japan Ltd., trade name: Laromer TPGDA Trifunctional (meth)acrylate monomer (b1): EO-added trimethylolpropane triacrylate (TMP(EO)TA), manufactured by Toagosei Co., Ltd., product name: Aronix M-350 Tri- to tetrafunctional (meth)acrylate monomer (b1): pentaerythritol triacrylate / pentaerythritol tetraacrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: Viscoat #300 Penta- to hexafunctional (meth)acrylate monomer: dipentaerythritol penta / hexaacrylate (DPPA / DPHA), manufactured by Toagosei Co., Ltd., product name: Aronix M-400 ((C) component) Photopolymerization initiator: Benzophenone, manufactured by ChemFine Co., Ltd., trade name: HYCURE BENZOPHENONE ((D) component) Inorganic particle 1 (d1): Silica, average particle diameter (D 50 ) 5.0 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., trade name: Mizukasil P-802Y Inorganic particles 2 (d1): Silica, average particle size (D 50 ) 4.4 μm, manufactured by EVONIK Co., Ltd., product name: Ace Mat OK607 Inorganic particles 3 (d1): Silica, average particle size (D 50 ) 3.0 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., trade name: Mizukasil P-763 Inorganic particles 4 (d1): aluminosilicate particles, average particle size (D50) 5.0 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., trade name: Shilton JC-50 Inorganic particles 5 (d1): aluminosilicate particles, average particle size (D50) 10.4 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., trade name: Silton AMT-100R Urethane resin particles 1 (d2 + d1): a mixture of urethane resin particles (d2) (96% by mass) and amorphous silica (d1) (4% by mass), manufactured by Negami Chemical Industrial Co., Ltd., product name: Art Pearl AK-800TR Urethane resin particles 2 (d2 + d1): a mixture of urethane resin particles (d2) (97% by mass) and amorphous silica (d1) (3% by mass), manufactured by Negami Chemical Industrial Co., Ltd., product name: Art Pearl C-600T Acrylic resin particles 1 (d3): Crosslinked PMMA particles, average particle diameter (D 50 ) 20.0 μm, Aica Kogyo Co., Ltd., Ganz Pearl GM-2001 Acrylic resin particles 2 (d3): Crosslinked PBMA particles, average particle diameter (D 50 ) 15.0 μm, Aica Kogyo Co., Ltd., Ganz Pearl GB-15 The average particle size of each particle (D 50 ) is a value measured using a laser diffraction / scattering particle size distribution analyzer "Microtrac MT3000II" (manufactured by Microtrac Bell). IPA was used as the circulating solvent, and approximately 0.3 g of the sample in the example was added, and after being thoroughly dispersed by applying ultrasonic waves for 3 minutes, measurement was performed. The average particle diameter (D 50 ) was obtained.

[0053] [Examples 1 to 12, Comparative Examples 1 to 5] [Production of active energy ray-curable coating composition] The components were mixed and stirred according to the formulations shown in Tables 1 and 2 to prepare active energy ray-curable coating compositions.

[0054] [Table 1]

[0055] [Table 2]

[0056] [Example of manufacturing a substrate with a cured coating] Each of the active energy ray-curable coating compositions prepared above was applied to a substrate (synthetic resin flooring, 3 mm thick) using a natural roll coater to a film thickness of 20 μm. Subsequently, the coated surface of the substrate was irradiated with UV (500 mJ / 100 mW) using a high-pressure mercury lamp to cure the coating film, forming a cured coating film, and a substrate with a cured coating film was obtained.

[0057] [Evaluation of substrate with cured coating] (crack resistance) The crack resistance of the cured coating film of each of the substrates with a cured coating film produced above was evaluated by a flex test. Specifically, each of the substrates with a cured coating film produced above was wrapped around a cylindrical mandrel testing machine (1 inch diameter) with the cured coating film facing outward. The appearance of the cured coating film was then visually observed, and the crack resistance was evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A rating of "◎" or "◯" indicates a passing grade. (Evaluation criteria) ⊚: No cracks were observed. ○: Only small cracks were observed, but no major cracks were observed. ×: Cracks were observed.

[0058] (Stain resistance) The stain resistance of the cured coating film of each substrate with a cured coating film prepared as described above was evaluated in accordance with a heel mark resistance test. Specifically, a commercially available UV-curable paint (manufactured by Chugoku Paint Co., Ltd., product name: Aurex No. 160) was applied to a 3 mm-thick synthetic resin flooring material using a roll coater so that the cured coating film thickness was 20 μm. The paint was then cured in the same manner as described above to obtain a standard test panel. Next, a heel mark resistance test based on JIS K 3920 was performed on the surface of the cured coating film-containing substrate prepared as described above and the surface of a control standard test panel using a Snell capsule tester for 5,000 revolutions, and the stain adhesion area (%) relative to the surface area was measured. The stain score (relative value) of the surface of each cured coating film-containing substrate was calculated, with the adhesion area of ​​the standard test panel being given a score of 100, and the stain resistance was evaluated according to the following criteria. The measurement and evaluation results are shown in Tables 3 and 4. A rating of "◎" or "○" indicates a pass. (Evaluation criteria) ◎: The score was less than 100. ○: Score was 100 or more but less than 150. ×: score was 150 or more.

[0059] (wear resistance) The abrasion resistance of the cured coating film of each of the substrates with cured coatings prepared above was evaluated in accordance with the JIS A 1453 abrasion test. Specifically, the surface of each substrate with cured coating prepared above was observed every 10 revolutions of the JIS A 1453 abrasion test, and the number of revolutions at which the coating film was completely worn away and the pattern on the substrate surface began to wear away was recorded and evaluated according to the following criteria. The measurement and evaluation results are shown in Tables 3 and 4. A rating of "◎" or "○" indicates a pass. (Evaluation criteria) ◎: 60 revolutions or more. 〇: It was 50 rotations. ×: 40 revolutions or less.

[0060] [Table 3]

[0061] Table 4

Claims

1. An active energy ray-curable coating composition for flooring materials, comprising a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and particles (D), the urethane (meth)acrylate (A) contains a trifunctional urethane (meth)acrylate (a1) and a hexafunctional urethane (meth)acrylate (a2); the content of the urethane (meth)acrylate (A) is 20% by mass or more and 60% by mass or less, based on 100% by mass of the solid content of the active energy ray-curable coating composition; the total content of the trifunctional urethane (meth)acrylate (a1) and the hexafunctional urethane (meth)acrylate (a2) is 70% by mass or more, based on the total amount of the urethane (meth)acrylate (A); the (meth)acrylate monomer (B) contains at least a (meth)acrylate monomer (b1) having a functional group number of 3 or more and 4 or less, and the content of the (meth)acrylate monomer (b1) having a functional group number of 3 or more and 4 or less is 20 mass% or more and 60 mass% or less with respect to the total amount of the (meth)acrylate monomer (B); the particles (D) include inorganic particles (d1), urethane resin particles (d2), and acrylic resin particles (d3); an active energy ray-curable coating composition for flooring, wherein the content of the particles (D) is 5% by mass or more and 30% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable coating composition; the content of the urethane resin particles (d2) is 15% by mass or more and 50% by mass or less, relative to the total amount of the particles (D); and the content of the acrylic resin particles (d3) is 5% by mass or more and 40% by mass or less, relative to the total amount of the particles (D).

2. 2. The active energy ray-curable coating composition according to claim 1, wherein the content of the trifunctional urethane (meth)acrylate (a1) is 20 mass% or more and 80 mass% or less based on the total of the trifunctional urethane (meth)acrylate (a1) and the hexafunctional urethane (meth)acrylate (a2).

3. 2. The active energy ray-curable coating composition according to claim 1, wherein the content of the (meth)acrylate monomer (B) is 20% by mass or more and 60% by mass or less, relative to 100% by mass of the solids content of the active energy ray-curable coating composition.

4. 2. The active energy ray-curable coating composition according to claim 1, wherein the content of the (meth)acrylate monomer (b1) having 3 or more and 4 or less functional groups is 30% by mass or more and 59% by mass or less, based on the total amount of the (meth)acrylate monomer (B).

5. 2. The active energy ray-curable coating composition according to claim 1, wherein the content of the inorganic particles (d1) is 20% by mass or more and 70% by mass or less based on the total amount of the particles (D).

6. 2. The active energy ray-curable coating composition according to claim 1, wherein the content of the acrylic resin particles (d3) is 7% by mass or more and 38% by mass or less relative to the total amount of the particles (D).

7. 2. The active energy ray-curable coating composition according to claim 1, wherein the flooring material is made of a synthetic resin.

8. A cured coating film formed from the active energy ray-curable coating composition according to any one of claims 1 to 7.

9. A substrate having a cured coating film formed from the active energy ray-curable coating composition according to any one of claims 1 to 7 on at least a portion of the surface of the substrate.

10. A step of applying the active energy ray-curable coating composition according to any one of claims 1 to 7 to at least a part of a surface of a substrate; a curing step of curing the active energy ray-curable coating composition by ultraviolet irradiation to form a cured coating film after the coating step; A method for producing a substrate with a cured coating film, comprising:

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