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

Abstract

To provide an active energy ray-curable resin composition capable of forming a cured coating film excellent in stain resistance, designability and flexibility.SOLUTION: The active energy ray-curable resin composition according to the present invention contains a photopolymerization initiator (A), spherical inorganic particles (B), and an active energy ray-curable resin (C) having at least one or more (meth)acryloyl groups. The photopolymerization initiator (A) contains methyl-o-benzoylbenzoate (a1) and a benzophenone-based photopolymerization initiator (a2) excluding (a1). The active energy ray-curable resin (C) contains at least one of a urethane (meth)acrylate and a polyester (meth)acrylate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable resin composition. The present invention also relates to a cured coating formed from the active energy ray-curable resin composition and a substrate coated with the cured coating. [Background technology]

[0002] Conventionally, a cured coating has been applied to the surface of a substrate such as a flooring material or an interior wall. The performance required for this cured coating includes contamination resistance and design. Regarding design, a low gloss surface is desired. Therefore, by adding particles to the cured coating, a low gloss surface is achieved by the particle-induced unevenness. However, the particle-induced unevenness present on the surface of the flooring material is easily scratched by the soles of shoes and luggage carriers when walking, and is particularly prone to soiling, so contamination resistance is required for the surface of the flooring material.

[0003] In order to improve low gloss and stain resistance, Patent Document 1 proposes the use of a photocurable resin composition containing a photocurable oligomer and / or photocurable resin (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C), and urethane resin particles (D) having an average particle size in the range of 1 to 30 μm, wherein the urethane resin particles (D) contain two or more types of particles having different average particle sizes. Furthermore, in order to improve low gloss and stain resistance, Patent Document 2 proposes the use of an active energy ray-curable resin composition containing (A) silica particles and (B) an active energy ray-curable resin, in which the content of the (A) silica particles is 12% by mass or more and 40% by mass or less, based on 100% by mass of the solid content of the active energy ray-curable resin composition, and the viscosity of the active energy ray-curable resin composition at 25°C is less than 110 KU.

[0004] Furthermore, synthetic resin flooring materials are often bent during installation, and if the crosslink density of the cured coating is too high, it will not conform to the substrate well and will be prone to cracking, so flexibility is required for the cured coating. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-84953 [Patent Document 2] Japanese Patent Publication No. 2022-30260 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the cured coatings described in Patent Documents 1 and 2 have room for improvement in terms of stain resistance and flexibility. Therefore, there is a need for the development of a cured coating that is excellent in stain resistance, designability, and flexibility.

[0007] Therefore, an object of the present invention is to provide an active energy ray-curable resin composition capable of forming a cured coating film having excellent stain resistance, designability, and flexibility. Another object of the present invention is to provide a cured coating film having excellent stain resistance, designability, and flexibility. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using an active energy ray-curable resin composition containing a specific photopolymerization initiator (A), spherical inorganic particles (B), and a specific active energy ray-curable resin (C). The present invention was completed based on this finding.

[0009] That is, according to the present invention, the following inventions are provided. [1] An active energy ray-curable resin composition comprising a photopolymerization initiator (A), spherical inorganic particles (B), and an active energy ray-curable resin (C) having at least one (meth)acryloyl group, the photopolymerization initiator (A) contains methyl-o-benzoylbenzoate (a1) and a benzophenone-based photopolymerization initiator (a2) other than (a1), The active energy ray-curable resin composition, wherein the active energy ray-curable resin (C) contains at least one of a urethane (meth)acrylate and a polyester (meth)acrylate. [2] The active energy ray-curable resin composition according to [1], wherein the content of the methyl-o-benzoylbenzoate (a1) is 0.1 mass% or more and 10 mass% or less, relative to 100 mass% of the solid content of the active energy ray-curable resin composition. [3] The active energy ray-curable resin composition according to [1] or [2], wherein the content of the benzophenone-based photopolymerization initiator (a2) is 0.1 mass % or more and 10 mass % or less, relative to 100 mass % of the solid content of the active energy ray-curable resin composition. [4] The active energy ray-curable resin composition according to any one of [1] to [3], wherein the oil absorption of the spherical inorganic particles (B) is 100 ml / 100 g or less. [5] The average particle diameter (D 50 ) is 1.0 μm or more. [6] The active energy ray-curable resin composition according to any one of [1] to [5], wherein the content of the spherical inorganic particles (B) is 1% by mass or more and 55% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable resin composition. [7] The active energy ray-curable resin composition according to any one of [1] to [6], wherein the weight average molecular weight per functional group (Mw / F) of the active energy ray-curable resin (C) is 400 or more. [8] The active energy ray-curable resin composition according to any one of [1] to [7], wherein the content of the active energy ray-curable resin (C) is 10% by mass or more and 70% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable resin composition. [9] The active energy ray-curable resin composition according to any one of [1] to [8], wherein the benzophenone-based photopolymerization initiator (a2) is at least one selected from the group consisting of 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4-phenylbenzophenone.

[10] The active energy ray-curable resin composition according to any one of [1] to [9], wherein the photopolymerization initiator (A) further contains a photopolymerization initiator (a3) ​​other than (a1) and (a2).

[11] The active energy ray-curable resin composition according to any one of [1] to

[10] , further comprising a monofunctional or bifunctional (meth)acrylate monomer (D).

[12] The active energy ray-curable resin composition according to any one of [1] to

[11] , which is for use as an interior material or an outdoor or semi-outdoor flooring material.

[13] A substrate having a cured coating, at least one surface of which is coated with a cured coating formed from the active energy ray-curable resin composition according to any one of [1] to

[12] .

[14] The substrate with a cured coating according to

[13] , wherein the substrate is for interior use or for outdoor or semi-outdoor flooring. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an active energy ray-curable resin composition capable of forming a cured coating having excellent stain resistance, designability, and flexibility. Also, according to the present invention, it is possible to provide a cured coating having excellent stain resistance, designability, and flexibility, and a substrate coated with the cured coating. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 resin composition, and which constitute a cured coating when cured.

[0012] <Active energy ray-curable resin composition> The active energy ray-curable resin composition according to the present invention contains at least a photopolymerization initiator (A), spherical inorganic particles (B), and an active energy ray-curable resin (C) having at least one (meth)acryloyl group. Such an active energy ray-curable resin composition can form a cured coating film that is excellent in stain resistance, designability, and flexibility.

[0013] Each component of the active energy ray-curable resin composition according to the present invention will be described in detail below.

[0014] (Photopolymerization initiator (A)) The photopolymerization initiator (A) contains methyl-o-benzoylbenzoate (a1) and a benzophenone-based photopolymerization initiator (a2) other than (a1), and may further contain a photopolymerization initiator (a3) ​​other than (a1) and (a2). In the present invention, by using a combination of methyl-o-benzoylbenzoate (a1) and a benzophenone-based photopolymerization initiator (a2) other than (a1), the surface curability of the coating can be improved, and the contamination resistance can be improved.

[0015] From the viewpoint of the surface curability of the cured coating, the content of methyl-o-benzoylbenzoate (a1) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 8% by mass or less, and even more preferably 0.3% by mass or more and 6% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable resin composition.

[0016] (Benzophenone-based photopolymerization initiator (a2) excluding (a1)) Examples of the benzophenone-based photopolymerization initiator (a2) other than (a1) include benzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, 4-hydroxybenzophenone, benzoylbenzoic acid, 2,4,6-trimethylbenzophenone, 4,4'-diaminobenzophenone, and 4-benzoyl-4'-methyldiphenyl sulfide. Among these, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4-phenylbenzophenone are preferred. These benzophenone-based photopolymerization initiators (a2) may be used alone or in combination of two or more.

[0017] From the viewpoint of the surface curability of the cured coating, the content of the benzophenone-based photopolymerization initiator (a2) is preferably from 0.1 to 10% by mass, more preferably from 0.2 to 8% by mass, and even more preferably from 0.3 to 6% by mass, relative to 100% by mass of the solid content of the active energy ray-curable resin composition.

[0018] (Photopolymerization initiator (a3) ​​other than (a1) and (a2)) The photopolymerization initiator (a3) ​​other than (a1) and (a2) is not particularly limited, and any conventionally known photopolymerization initiator for ultraviolet curing can be used. Examples of the photopolymerization initiator (a3) ​​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, and α-aminoalkylphenone-based photopolymerization initiators. 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 2,4-diethylthioxanthone and isopropylthioxanthone. Examples of the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), and the like. Examples of the hydroxybenzoyl-based photopolymerization initiator include benzoin alkyl ether. Examples of the α-aminoalkylphenone photopolymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and the like. These photopolymerization initiators (a3) ​​may be used alone or in combination of two or more.

[0019] From the viewpoint of the surface curability of the cured coating, the content of the photopolymerization initiator (a3) ​​is preferably from 0.1 to 5% by mass, more preferably from 0.1 to 2.5% by mass, and even more preferably from 0.1 to 2.0% by mass, relative to 100% by mass of the solid content of the active energy ray-curable resin composition.

[0020] (Spherical inorganic particles (B)) Examples of the spherical inorganic particles (B) include silica, glass, alumina, and aluminosilicate. Among these, silica is preferred. These spherical inorganic particles (B) may be used alone or in combination of two or more.

[0021] The oil absorption of the spherical inorganic particles (B) is preferably 100 ml / 100 g or less, more preferably 90 ml / 100 g or less, even more preferably 70 ml / 100 g or less, and preferably 1 ml / 100 g or more, more preferably 5 ml / 100 g or more. When the oil absorption of the spherical inorganic particles is within the above-mentioned range, even when a large amount of the spherical inorganic particles is blended into the active energy ray-curable resin composition, the viscosity of the active energy ray-curable resin composition is unlikely to increase, making the composition suitable for use as a coating material. Furthermore, by blending a large amount of the spherical inorganic particles into the active energy ray-curable resin composition, the cured coating film formed from the active energy ray-curable resin composition has low gloss, improving design and surface strength of the coating film. The oil absorption of the spherical inorganic particles can be measured in accordance with JIS K 5101-13-2.

[0022] The average particle size of spherical inorganic particles (B) (D 50 ) is preferably 1.0 μm or more, more preferably 1.5 μm or more, even more preferably 2 μm or more, and is preferably 100 μm or less, more preferably 80 μm or less, even more preferably 50 μm or less. The average particle diameter (D 50 ) is within the above range, the cured coating formed from the active energy ray-curable resin composition has low gloss, improved design properties, and improved stain resistance. The average particle diameter of the spherical inorganic particles (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).

[0023] From the viewpoint of the physical properties of the cured coating, the content of the spherical inorganic particles (B) is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 5% by mass or more, and is preferably 55% by mass or less, more preferably 45% by mass or less, even more preferably 35% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable resin composition.

[0024] (Active energy ray curable resin (C)) The active energy ray-curable resin (C) has at least one (meth)acryloyl group as a functional group in the molecule. When the active energy ray-curable resin (C) is irradiated with energy, the unsaturated double bonds are polymerized to form a cured coating (cured product). In the present invention, at least one of urethane (meth)acrylate and polyester (meth)acrylate is used as the active energy ray-curable resin (C).

[0025] (urethane (meth)acrylate) The urethane (meth)acrylate (A) has at least one (meth)acryloyl group as a functional group and a urethane bond in the molecule. The urethane (meth)acrylate is not particularly limited, but can be obtained, for example, by reacting a polyisocyanate with a hydroxyl group-containing (meth)acrylate and, if necessary, a polyol other than the hydroxyl group-containing (meth)acrylate. The urethane (meth)acrylate (A) is preferably an oligomer or polymer. The urethane (meth)acrylate (A) may be modified 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.

[0026] The polyisocyanate can be obtained by reacting a polyol with a diisocyanate. The polyol, which is a raw material for synthesizing the polyisocyanate, is not particularly limited, but examples thereof include polyester polyols, polyether polyols, and polycarbonate polyols. These may be used alone or in combination of two or more.

[0027] 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 and a dicarboxylic acid or a dicarboxylic acid chloride to a polycondensation reaction, or by esterifying a diol or a dicarboxylic acid and subjecting it to an ester exchange 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.

[0028] The polyether polyol is not particularly limited, but examples thereof include polyethylene oxide, polypropylene oxide, and ethylene oxide-propylene oxide random copolymers.

[0029] 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, as well as 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.

[0030] The diisocyanate used as a raw material for synthesizing polyisocyanate is not particularly limited, but may be a linear or alicyclic aliphatic diisocyanate, or an aromatic diisocyanate. Specific examples include linear hydrocarbon group-containing diisocyanates such as tetramethylene diisocyanate and hexamethylene diisocyanate; branched hydrocarbon group-containing diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate; cyclic hydrocarbon group-containing diisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate and hydrogenated toluene diisocyanate; and aromatic hydrocarbon group-containing diisocyanates 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.

[0031] The hydroxyl group-containing (meth)acrylate may be a (meth)acrylate having at least one hydroxyl group, preferably 1 to 5 hydroxyl groups. Furthermore, it is desirable that such a hydroxyl group-containing (meth)acrylate has a hydrocarbon moiety preferably 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).

[0032] Examples of the (meth)acrylate monomer having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and their caprolactone adducts (e.g., Plaxel FA1 and FA2 manufactured by Daicel Corporation), hydroxyl group-terminated polyalkylene glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate, and ethylene oxide-modified products thereof (e.g., AM-90G and AM-130G manufactured by Shin-Nakamura Chemical Co., Ltd., Light Acrylate EC-A, MTG-A, and EHDG-AT manufactured by Kyoeisha Chemical Co., Ltd.), glycerin mono(meth)acrylate (e.g., Blenmer GLM manufactured by NOF Corporation), and glycerin diacrylate. (meth)acrylates (such as Aronix MT3560 manufactured by Toagosei Co., Ltd.), isocyanuric acid EO-modified di(meth)acrylates (such as Aronix M-313 and 315 manufactured by Toagosei Co., Ltd.), pentaerythritol tri(meth)acrylates (such as Viscoat 300 manufactured by Osaka Organic Chemical Industry Co., Ltd., Aronix M-305, M-306, and MT-3548 manufactured by Toagosei Co., Ltd., Light Acrylate PE-3A manufactured by Kyoeisha Chemical Co., Ltd., and NK Ester A-TMM-3L manufactured by Shin-Nakamura Chemical Co., Ltd.), and dipentaerythritol penta(meth)acrylates (such as Aronix M-400, M-402, M-403, and MT-3549 manufactured by Toagosei Co., Ltd., Light Acrylate DPE-6A manufactured by Kyoeisha Chemical Co., Ltd., and NK Ester A-DPH manufactured by Shin-Nakamura Chemical Co., Ltd.). Such hydroxyl group-containing (meth)acrylates may be used alone or in combination of two or more.

[0033] As the polyol other than the hydroxyl group-containing (meth)acrylate, which is used as needed, known polyols such as polyether polyols, polyester polyols, and polyolefin polyols can be used. Specific examples include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, polycaprolactone polyols, and alkylene diols. Such polyols may be used alone or in combination of two or more.

[0034] (Polyester (meth)acrylate) The polyester (meth)acrylate has at least one (meth)acryloyl group as a functional group and an ester bond in the molecule. The polyester (meth)acrylate (A) is preferably an oligomer or polymer, more preferably an oligomer. Examples of the polyester (meth)acrylate include a dehydration condensate of a polyester polyol and (meth)acrylic acid.

[0035] 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 and a dicarboxylic acid or a dicarboxylic acid chloride to a polycondensation reaction, or by esterifying a diol or a dicarboxylic acid and subjecting it to an ester exchange 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.

[0036] Among the above active energy ray-curable resins (C), polyfunctional ones are preferred. The number of functional groups in the active energy ray-curable resin (C) is preferably 2 or more, more preferably 3 or more, and may be 12 or less, or may be 10 or less.

[0037] The weight average molecular weight (Mw / F) per functional group of the active energy ray-curable resin (C) is preferably 400 or more, more preferably 500 or more, and is preferably 10,000 or less, more preferably 8,000 or less, and even more preferably 6,000 or less. When the weight average molecular weight (Mw / F) per functional group of the active energy ray-curable resin is within the above-mentioned range, it is possible to form a cured coating film that is excellent in stain resistance, designability, and flexibility. The weight average molecular weight (Mw) of the active energy ray curable resin can be measured using gel permeation chromatography (GPC). The weight average molecular weight (Mw) of the active energy ray curable resin is a standard polystyrene equivalent value. The weight average molecular weight (Mw) of the active energy ray curable resin (C) is a value excluding the monomer. When one type of active energy ray-curable resin is used, the weight average molecular weight (Mw / F) per functional group of the single active energy ray-curable resin is calculated as follows. Weight average molecular weight per functional group of active energy ray-curable resin (Mw / F) = Weight average molecular weight of active energy ray-curable resin (Mw) / Number of functional groups of active energy ray-curable resin (F) When multiple types of active energy ray curable resins are used, the weight average molecular weight (Mw mix / F mix ) is calculated as follows: The weight average molecular weight (Mw) per functional group of an active energy ray curable resin that is a mixture of multiple types of active energy ray curable resins mix / F mix )=(Mw1 / F1)*(M1 / (M1+M2+...+Mx))+(Mw2 / F2)*(M2 / (M1+M2+...+Mx))++(Mwx / Fx)*(Mx / (M1+M2+...+Mx)) Mw1 to Mwx: Weight average molecular weight of each active energy ray curable resin F1 to Fx: Number of functional groups in each active energy ray-curable resin M1 to Mx: Mass (g) of each active energy ray-curable resin

[0038] From the viewpoint of the physical properties of the cured coating, the content of the active energy ray-curable resin (C) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the solid content of the active energy ray-curable resin composition, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less.

[0039] (Monofunctional or difunctional (meth)acrylate monomer (D)) The (meth)acrylate monomer (D) is a monomer having one or two (meth)acryloyl groups. When the active energy ray-curable resin composition is irradiated with ultraviolet light, the (meth)acrylate monomer forms a cured coating together with the active energy ray-curable resin (C). The monofunctional or bifunctional (meth)acrylate monomer may also serve as a reactive diluent that adjusts the viscosity of the active energy ray-curable resin composition.

[0040] Examples of monofunctional and bifunctional (meth)acrylate monomers include (meth)acryloylmorpholine, phenoxy polyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate. alkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, 1,10-decanediol diacrylate, and neopentyl glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 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; di(meth)acrylates of aliphatic polyols such as trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, and pentaerythritol di(meth)acrylate; hydrogenated dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and the like; Di(meth)acrylates of dioctyl pentadiene or tricyclodecane dialkanol; 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); 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;Examples of suitable epoxy di(meth)acrylates include epoxy di(meth)acrylates of bisphenol A or bisphenol F, such as the acrylic acid adduct of bisphenol A diglycidyl ether and the acrylic acid adduct of bisphenol F diglycidyl ether; silicone di(meth)acrylates; di(meth)acrylate of hydroxypivalic acid neopentyl glycol ester; 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. Among these bifunctional (meth)acrylate monomers, alkylene glycol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, di(meth)acrylate of halogen-substituted alkylene glycol, di(meth)acrylate of aliphatic polyol, di(meth)acrylate of hydrogenated dicyclopentadiene or tricyclodecane dialkanol, di(meth)acrylate of dioxane glycol or dioxane dialkanol, silicone di(meth)acrylate, Examples of suitable (meth)acrylates include di(meth)acrylate of hydroxypivalic acid neopentyl glycol ester, 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 (meth)acrylate monomers may be modified monomers, such as silicone-modified or fluorine-modified. These (meth)acrylate monomers may be used alone or in combination of two or more.

[0041] From the viewpoint of the physical properties of the cured coating, the content of the (meth)acrylate monomer (D) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the solid content of the active energy ray-curable resin composition, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0042] (Trifunctional or higher polyfunctional (meth)acrylate (E)) The active energy ray-curable resin composition according to the present invention may further contain a tri- or higher functional (meth)acrylate (E). The number of functional groups in the polyfunctional (meth)acrylate (E) is preferably from 3 to 10, more preferably from 3 to 6.

[0043] Examples of the trifunctional or higher polyfunctional (meth)acrylate 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 is n=2), PO-added trimethylolpropane tri(meth)acrylate (PO portion is n=3), glycerin PO-added tri(meth)acrylate, 2-(meth)acryloyloxypropyl tetrahydrohydrogen terephthalate, PO-added glycol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphite, ester, pentaerythritol tri(meth)acrylate, EO-added pentaerythritol tri(meth)acrylate, tris((meth)acryloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, alkoxylated dipentaerythritol hexa(meth)acrylate, EO-added pentaerythritol tetra(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, polycaprolactone-modified dipentaerythritol hexa(meth)acrylate, alkylene oxide-modified dipentaerythritol polyfunctional (meth)acrylate, etc. These (meth)acrylate monomers may be modified monomers by silicone modification, fluorine modification, etc.

[0044] From the viewpoint of the physical properties of the cured coating, the content of the tri- or higher functional polyfunctional (meth)acrylate (E) is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, relative to 100% by mass of the solid content of the active energy ray-curable resin composition, and may also be 0.1% by mass or more, or 1% by mass or more.

[0045] (Other ingredients) In addition to the above-mentioned components, the active energy ray-curable resin composition according to the present invention may further contain, as necessary, a polymerization inhibitor, a dispersant, a leveling agent, a non-reactive diluent, an antifoaming agent, an anti-settling agent, a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antifouling property improver, an agent for improving adhesion to a substrate, a photosensitizer, an antistatic agent, a scratch resistance agent, an antifungal agent, an antiviral agent, a matting agent, a silane coupling agent, a plasticizer, and the like, as long as the object of the present invention is not impaired.

[0046] The active energy ray-curable resin composition according to this embodiment may be either a solvent-based resin composition diluted with an organic solvent (non-reactive diluent) such as thinner or alcohol, or a solventless resin composition that does not require dilution with an organic solvent. However, a solventless resin composition is preferred because it leaves no residual volatile organic compounds (VOCs), has no effect on the human body, and is environmentally friendly.

[0047] (Method for preparing active energy ray-curable resin composition) The active energy ray-curable resin 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.

[0048] [Substrate with cured film] The substrate with a cured coating according to the present invention has at least one surface covered with a cured coating formed from the active energy ray-curable resin composition. The cured coating may be provided over the entire surface of one surface of the substrate, only a portion of one surface, or both surfaces of the substrate. When provided over a portion of the surface, the form of the cured coating is not particularly limited, and any form can be used without particular limitation, such as a sea-island pattern, a sea or island pattern, a lattice pattern, or a mosaic pattern.

[0049] (base material) In the present invention, the substrate can be used as an interior material. Interior materials refer to components used inside buildings, vehicles, etc. Examples include windows, walls, ceilings, floors, roofs, fixtures, and wallpaper. The substrate can also be used as an outdoor or semi-outdoor flooring material. Flooring and wall materials are particularly preferred, with flooring being more preferred. Examples of the substrate include wood substrates and substrates made of synthetic resins. Examples of wood substrates include plywood, solid wood, hardboard, and particle board. 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. Among these, when used for synthetic resin flooring, thermoplastic resins are preferred in terms of processability and ease of application as a flooring material, and vinyl chloride resins are more preferred. The thickness of the substrate is not particularly limited, but is preferably 0.2 to 50 mm, more preferably 1 to 20 mm.

[0050] (hardened film) The cured coating is formed from the active energy ray-curable resin composition. The thickness of the cured coating is not particularly limited, but is generally 1 to 100 μm, preferably 3 to 70 μm, and more preferably 5 to 50 μm. From the viewpoints of drying and curing properties, the upper limit is preferably 100 μm, and from the viewpoints of abrasion resistance and contamination resistance, the lower limit is preferably 1 μm. In the present invention, the thickness refers to the thickness of the cured coating when the cross section of the cured coating is observed with an optical microscope, a scanning electron microscope (SEM), or the like. When forming a coating of such a thickness, the desired thickness may be formed by a single coating, or by multiple coatings.

[0051] <Method of manufacturing substrate with cured coating> The substrate with a cured coating according to the present invention comprises a step of applying the above-described active energy ray-curable resin composition to at least one surface of the substrate (application step), and a step of irradiating the applied surface with active energy rays to cure the composition (curing step).

[0052] (Coating process) The coating step is a step of coating at least one surface of a substrate with the active energy ray-curable resin composition 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, or a blade coater can be used for coating. Among these, a coating method using a roll coater is preferred from the viewpoints of workability and productivity.

[0053] The thickness of the applied film after curing and drying is preferably in the range of the thickness of the cured film described above.

[0054] When the active energy ray-curable resin composition is used after diluting with a solvent, it is preferable to dry it after application. Examples of the drying method include 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.

[0055] (hardening process) The curing step is a step of irradiating the coated surface of the substrate with active energy rays to cure the applied active energy ray-curable resin composition to form a cured coating. 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, ease of availability of irradiation equipment, cost, etc.

[0056] When the active energy ray-curable resin composition according to the present invention is cured by light such as ultraviolet light, a photopolymerization initiator is used. On the other hand, when the active energy ray-curable resin composition according to the present invention is cured by electron beam or the like, a photopolymerization initiator is usually not required.

[0057] 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. The irradiation dose of ultraviolet light is preferably 100 to 3,000 mJ / cm from the viewpoints of the curability of the active energy ray-curable resin composition and the flexibility of the cured product. 2 and more preferably 200 to 2,000 mJ / cm 2 is. [Example]

[0058] 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.

[0059] First, in order to prepare an active energy ray-curable resin composition, the following raw materials were prepared. (Photopolymerization initiator) (a1) Photopolymerization initiator 1: methyl-o-benzoylbenzoate, manufactured by IGM Resins Co., Ltd., trade name: Omnirad OMBB (a2) Photopolymerization initiator 2: 4-methylbenzophenone, manufactured by IGM Resins Co., Ltd., trade name: Omnirad 4MBZ Flakes (a2) Photopolymerization initiator 3: a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone, manufactured by IGM Resins Co., Ltd., trade name: Omnirad TZT (a3) Photopolymerization initiator 4: methyl benzoyl formate, manufactured by IGM Resins Co., Ltd., trade name: Omnirad MBF (a3) Photopolymerization initiator 5: 2,4-diethylthioxanthone, manufactured by IGM Resins Co., Ltd., trade name: Omnirad DETX (a3) Photopolymerization initiator 6: a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester, manufactured by IGM Resins Co., Ltd., trade name: Omnirad 754 (a3) Photopolymerization initiator 7: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, manufactured by Chitec Technology Co., Ltd., trade name: CHIVACURE TPO (particle) ·(B) Inorganic particle 1: Spherical, silica, oil absorption: 51ml / 100g, average particle diameter (D 50 ): 12.5 μm, manufactured by Evonik Japan Co., Ltd., product name: Spherilex DP-0115 ·(B) Inorganic particles 2: Spherical, silica, oil absorption: 55ml / 100g, average particle size (D 50 ): 5.5 μm, manufactured by Evonik Japan Co., Ltd., product name: Spherilex DP-0111 ·(B) Inorganic particles 3: Spherical, silica, oil absorption: 55ml / 100g, average particle diameter (D 50 ): 4.4 μm, manufactured by Evonik Japan Co., Ltd., product name: Spherilex DP-0110 Inorganic particles 4: irregular shape, silica, oil absorption: 79 ml / 100 g, average particle size: 6.0 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., product name: Mizukasil P-766 Inorganic particles 5: irregular shape, silica, oil absorption: 344 ml / 100 g, average particle size: 5.0 μm, manufactured by Mizusawa Industrial Chemicals, Ltd., product name: Mizukasil P-802Y ·Organic particle 1: spherical, acrylic resin, oil absorption: 53ml / 100g, average particle size (D 50 ):6.5μm, manufactured by Negami Kogyo Co., Ltd., product name: ART PEARL BE-006T Organic particles 2: spherical, urethane resin, oil absorption: 61 ml / 100 g, average particle diameter (D 50 ):6.0μm, manufactured by Negami Kogyo Co., Ltd., product name: ART PEARL AK-800TR 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. The oil absorption (mL / 100g) of each particle was measured in accordance with JIS K5101-13-2. Specifically, the sample (1-2g) was weighed based on the expected oil absorption, placed on a glass plate, and linseed oil (Sigma-Aldrich) in a burette was gradually added to the center of the sample, 4-5 drops at a time. Each time, the entire sample was thoroughly mixed with a palette knife. The addition and mixing were repeated until a hard, putty-like mass was formed. The end point was reached when the final drop could be rolled into a spiral shape with a palette knife. The operation time to reach the end point was between 7 and 15 minutes. The amount of linseed oil added in the burette was then read. The oil absorption is calculated by the following formula: Oil absorption (mL / 100g) = Amount of linseed oil used (mL) × 100 / Weight of sample (g) (resin) (C) Urethane (meth)acrylate 1: Number of functional groups: 2, molecular weight: Mw: 2726, Mw / F=1363, manufactured by Mitsubishi Chemical Corporation, trade name: Shiko UV-6630B (C) Urethane (meth)acrylate 2: number of functional groups: 4, molecular weight Mw: 20879, Mw / F=5220, manufactured by Negami Chemical Industrial Co., Ltd., trade name: ART RESIN CWD-8E26 (C) Urethane (meth)acrylate 3: number of functional groups: 3, molecular weight Mw: 1707, Mw / F=569, manufactured by Negami Chemical Industrial Co., Ltd., trade name: ART RESIN SMT-001 (C) Polyester (meth)acrylate: number of functional groups: 6, molecular weight: Mw: 5281, Mw / F=880, manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd., trade name: MIRAMER PS610 (C) Urethane (meth)acrylate 4: silicone-modified, functional group number 10, molecular weight Mw 6159, Mw / F=616, manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd., trade name: MIRAMER SIU2400 ((Meth)acrylate Monomer) (D) (Meth)acrylate monomer 1: triethylene glycol monomethyl ether acrylate, having one functional group, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: GX-8301S (D) (Meth)acrylate monomer 2: 2-phenoxyethyl acrylate having one functional group, manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd., trade name: MIRAMER M140 (D) (Meth)acrylate monomer 3: 1,6-hexanediol diacrylate EO adduct with 2 functional groups, manufactured by MIWON SPECIALTY CHEMICAL Co., Ltd., trade name: MIRAMER M202 (D) (Meth)acrylate monomer 4: 1,9-nonanediol diacrylate having two functional groups, manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate 19ND-A (Other ingredients) Polymerization inhibitor: Hydroquinone, manufactured by Ube Industries, Ltd., product name: Hydroquinone Dispersant: BYK Co., Ltd., product name: DISPERBYK-2164 Leveling agent: Evonik Japan Co., Ltd., product name: TEGO rad 2300 Antifoaming agent: BYK Co., Ltd., product name: BYK-1790

[0060] [Examples 1 to 14, Comparative Examples 1 to 11] <Production of active energy ray-curable resin composition> According to the formulations shown in Tables 1 and 2, the components were mixed and stirred using a disper to produce active energy ray-curable resin compositions.

[0061] [Table 1]

[0062] [Table 2]

[0063] <Measurement of weight average molecular weight (Mw) of active energy ray curable resin (C)> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the active energy ray-curable resins (urethane (meth)acrylate and polyester (meth)acrylate) were measured using a gel permeation chromatography (GPC) "HLC-8320GPC" (Tosoh Corporation). The column used was a TSKgel SuperHZM-N* TSKgel SuperHZ2000 x 2 (Tosoh Corporation). A calibration curve was also created using EasiVial PS-H (Agilent) as the standard polystyrene. Measurements were performed at a column oven temperature of 40°C using 10 μL of a solution of the active energy ray-curable resin dissolved in tetrahydrofuran to a concentration of 0.4% by mass. The weight-average molecular weight (Mw) of the active energy ray-curable resin was calculated in terms of standard polystyrene. The weight-average molecular weight (Mw) of the active energy ray-curable resin (C) is a value excluding the monomer. The measurement results are shown in Tables 3 and 4.

[0064] When using one type of active energy ray curable resin, the method for calculating the weight average molecular weight (Mw / F) per functional group of a single active energy ray curable resin is as follows: Weight average molecular weight per functional group of active energy ray-curable resin (Mw / F) = Weight average molecular weight of active energy ray-curable resin (Mw) / Number of functional groups of active energy ray-curable resin (F)

[0065] When multiple types of active energy ray curable resins are used, the weight average molecular weight (Mw mix / F mix ) calculation method: The weight average molecular weight (Mw) per functional group of an active energy ray curable resin that is a mixture of multiple types of active energy ray curable resins mix / F mix )=(Mw1 / F1)*(M1 / (M1+M2+...+Mx))+(Mw2 / F2)*(M2 / (M1+M2+...+Mx))++(Mwx / Fx)*(Mx / (M1+M2+...+Mx)) Mw1 to Mwx: Weight average molecular weight of each active energy ray curable resin F1 to Fx: Number of functional groups in each active energy ray-curable resin M1 to Mx: Mass (g) of each active energy ray-curable resin

[0066] <Production of substrate (test specimen) with cured coating> For the test specimens for evaluating stain resistance and design, the active energy ray-curable resin composition obtained above was applied to a 3 mm thick vinyl chloride tile (Royal Stone, manufactured by Toli Co., Ltd.) using a roll coater so that the thickness of the cured film would be 15 μm. Subsequently, the coated surface of the vinyl chloride tile was irradiated with ultraviolet light using a high-pressure mercury lamp at an integrated light dose of 1000 mJ / cm. 2 and cured to obtain a test specimen.

[0067] For the test specimen for flexibility evaluation, the active energy ray-curable resin composition obtained above was applied to a 1.8 mm thick cushion floor sheet (CF Sheet-H, manufactured by Toli Co., Ltd.) using a bar coater so that the film thickness after curing would be 10 μm. Subsequently, the coated surface of the cushion floor sheet was irradiated with ultraviolet light using a high-pressure mercury lamp with an integrated light dose of 1000 mJ / cm. 2 and cured to obtain a test specimen.

[0068] <Evaluation of substrate (test specimen) with cured coating> (Stain resistance) Stain resistance was evaluated using a soil and sand contamination simulation test. Specifically, a contaminant was prepared by mixing 150 g of silicon carbide (Nichika Corporation, product name: #80 Carborundum) with 2 g of powdered carbon black (Mitsubishi Chemical Corporation, product name: Mitsubishi Carbon Black MA100). Next, 3 g of the contaminant was placed on the cured coating surface of a test specimen (6 cm long x 6 cm wide), spread evenly over the cured coating surface, and rubbed with a Kimtowel cloth. The contaminant on the cured coating surface was then lightly removed with a brush and then wiped dry with a Kimtowel cloth. The color difference ΔE between the cured coating surface before and after the test was measured using a color difference meter (JUKI Corporation, product name: AY-555), and stain resistance was evaluated according to the following criteria. (Evaluation criteria) ⊚: The color difference ΔE of the cured coating surface before and after the test was less than 10. ◯: The color difference ΔE of the cured coating surface before and after the test was 10 or more and less than 15. ×: The color difference ΔE of the cured coating surface before and after the test was 15 or more.

[0069] (Design) The design was evaluated by 60° specular gloss. Specifically, the 60° specular gloss of the cured coating surface of the test specimen was measured using a 60° specular gloss meter (IG-320 manufactured by HORIBA Corporation), and the design was evaluated according to the following criteria. (Evaluation criteria) Good: The 60° specular gloss was less than 35. ×: The 60° specular gloss was 35 or more.

[0070] (Flexibility) Flexibility was evaluated by a bending test. Specifically, a test specimen (10 cm long x 3 cm wide) was wrapped around a bending tester (1-inch mandrel bending tester). The number of cracks on the cured coating surface of the test specimen was then counted using a laser microscope (Keyence Corporation, Laser Microscope VK-X1000), and flexibility was evaluated according to the following criteria. (Evaluation criteria) ◎: The number of cracks of 1 mm or more was less than 5. Good: The number of cracks of 1 mm or more was 5 or more but less than 20. ×: The number of cracks of 1 mm or more was 20 or more.

[0071] [Table 3]

[0072] [Table 4]

Claims

1. An active energy ray-curable resin composition comprising a photopolymerization initiator (A), spherical inorganic particles (B), and an active energy ray-curable resin (C) having at least one (meth)acryloyl group, the photopolymerization initiator (A) contains methyl o-benzoyl benzoate (a1) and a benzophenone-based photopolymerization initiator (a2) other than (a1), The active energy ray-curable resin composition, wherein the active energy ray-curable resin (C) contains at least one of a urethane (meth)acrylate and a polyester (meth)acrylate.

2. 2. The active energy ray-curable resin composition according to claim 1, wherein the content of the methyl o-benzoyl benzoate (a1) is 0.1 mass% or more and 10 mass% or less, relative to 100 mass% of the solids content of the active energy ray-curable resin composition.

3. 2. The active energy ray-curable resin composition according to claim 1, wherein a content of the benzophenone-based photopolymerization initiator (a2) is 0.1 mass% or more and 10 mass% or less, relative to 100 mass% of a solid content of the active energy ray-curable resin composition.

4. 2. The active energy ray-curable resin composition according to claim 1, wherein the spherical inorganic particles (B) have an oil absorption of 100 ml / 100 g or less.

5. The average particle diameter (D ５０ 2. The active energy ray-curable resin composition according to claim 1, wherein the average particle diameter of the active energy ray-curable resin composition is 1.0 μm or more.

6. 2. The active energy ray-curable resin composition according to claim 1, wherein the content of the spherical inorganic particles (B) is 1% by mass or more and 55% by mass or less, relative to 100% by mass of a solid content of the active energy ray-curable resin composition.

7. 2. The active energy ray-curable resin composition according to claim 1, wherein the active energy ray-curable resin (C) has a weight average molecular weight per functional group (Mw / F) of 400 or more.

8. 2. The active energy ray-curable resin composition according to claim 1, wherein a content of the active energy ray-curable resin (C) is 10 mass% or more and 70 mass% or less, relative to 100 mass% of a solid content of the active energy ray-curable resin composition.

9. The active energy ray-curable resin composition according to claim 1, wherein the benzophenone-based photopolymerization initiator (a2) is at least one selected from the group consisting of 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4-phenylbenzophenone.

10. 2. The active energy ray-curable resin composition according to claim 1, wherein the photopolymerization initiator (A) further comprises a photopolymerization initiator (a3) ​​other than (a1) and (a2).

11. The active energy ray-curable resin composition according to claim 1 , further comprising a monofunctional or difunctional (meth)acrylate monomer (D).

12. The active energy ray-curable resin composition according to any one of claims 1 to 11, which is used for interior materials, or for outdoor or semi-outdoor flooring materials.

13. A substrate having a cured coating, at least one surface of the substrate being coated with a cured coating formed from the active energy ray-curable resin composition according to any one of claims 1 to 11.

14. The substrate with a cured coating according to claim 13, wherein the substrate is used for interior materials or outdoor or semi-outdoor flooring materials.

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