hardened artificial claw components

Abstract

To provide a curable artificial nail composition that enables the formation of a cured coating with high matte finish and superior leveling characteristics while preventing cracks and chips in the cured coating.SOLUTION: A curable artificial nail composition comprises the following (A)-(C): (A) a compound with a (meth)acryloyl group, (B) a polymerization initiator, and (C) polyurethane resin particles with a volume average particle diameter of 3 μm or greater and 30 μm or smaller. Relative to 100 pts.mass of the component (A), the component (C) is 15 pts.mass or more and 95 pts.mass or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable artificial nail composition.

Background Art

[0002] The popularity of nail art, which involves decorating natural nails on the hands and feet or attaching artificial nails and then decorating them, is increasing. In addition, in order to reinforce nails to prevent cracking and peeling due to external forces, artificial nails are formed on the nails. For such nail decoration and reinforcement, resin-containing materials called so-called manicure, pedicure, and sculpture are applied to the nails.

[0003] Recently, as a material used for nail decoration or reinforcement, a photo-curable artificial nail composition called gel nail has attracted attention. Gel nail is a photo-curable gel-like nail coating material (photo-curable artificial nail composition), and for example, those containing a (meth)acrylate-based oligomer and a (meth)acrylic monomer are known. Gel nail is applied to the nail and cured by irradiation with ultraviolet light, and a cross-linked polymer film is formed by a radical polymerization reaction, so it is said that a tough film that is difficult to peel off from the nail can be formed. As gel nails, those composed of three layers, a base layer provided on the nail, a color layer provided between the base layer and the top layer, and a top layer provided on the outermost surface, are widely known. Recently, in order to enhance the design of gel nails, it has become popular to provide a top layer (mat top) that eliminates gloss on the color layer, and the need for a curable artificial nail composition for forming such a top layer (mat top) that eliminates gloss is increasing.

[0004] As a curable artificial nail composition for forming a coating film that eliminates gloss, for example, the following are known. Patent Document 1 describes a photocurable resin composition for nails or artificial nails, comprising (A) component: a compound having a (meth)acryloyl group, (B) component: a photoinitiator, and (C) component: (meth)acrylic polymer particles with an average particle size of 3 to 21 μm, wherein the content of component (C) is 45 to 155 parts by mass per 100 parts by mass of component (A). Patent Document 2 describes a room-temperature curing composition for artificial nails, comprising (1) a liquid composition consisting of three components: monoacrylate and / or monomethacrylate, polymerizable polyacrylate and / or polymerizable polymethacrylate, and an organic hydroperoxide, and (2) a powder composition consisting of three components: a polymer powder mainly composed of bead-shaped polymer powder, thiourea and / or a thiourea derivative, and an organic vanadium compound. As the bead-shaped polymer powder, single and / or copolymer polymers such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and vinyl acetate are used. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2018 / 116798 [Patent Document 2] Japanese Patent Application Publication No. 55-108309 [Overview of the project] [Problems that the invention aims to solve]

[0006] Although Patent Documents 1 and 2 describe curable artificial nail compositions that achieve a matte finish, they have poor leveling properties for the coating film, and the cured coating film is brittle and prone to chipping, making them unsatisfactory for forming the top layer of gel nails. The problem that this invention aims to solve is to provide a curable artificial nail composition that can form a cured coating film with a high matte finish and excellent leveling properties, and that can form a cured coating film in which the occurrence of cracks and chips is suppressed. [Means for solving the problem]

[0007] The inventors of the present invention conducted diligent research to solve the above problems and found that the above problems can be solved by creating a curable artificial nail composition with a specific composition, thus completing the present invention. Specifically, it is as follows: [1] See (A) to (C) below; (A) Compounds having a (meth)acryloyl group, (B) Polymerization initiator, (C) Polyurethane resin particles with a volume-average particle diameter of 3 μm or more and 30 μm or less. It contains, With respect to 100 parts by mass of (A), the amount of (C) is 15 parts by mass or more and 95 parts by mass or less. Curable artificial nail composition. [Effects of the Invention]

[0008] The present invention provides a curable artificial nail composition that can form a cured coating film with a high matte finish and excellent leveling properties, and that can form a cured coating film in which cracking and chipping are suppressed, exhibiting remarkable effects.

[0009] The mechanism by which the curable artificial nail composition of the present invention can form a cured coating film that has a high matte finish and excellent leveling properties, and in which the occurrence of cracks and chips is suppressed, is unknown, but the inventors speculate as follows. In curable artificial nail compositions, when inflexible and hard acrylic resin particles are used as a matting agent, a large amount is required to achieve a good matte finish. Because acrylic resin particles are inflexible and hard, the cured coating becomes brittle, making it prone to cracking and chipping. On the other hand, polyurethane resin particles have appropriate flexibility and softness, thus eliminating the brittleness of the cured coating. Furthermore, by keeping the amount of polyurethane resin particles within a specific range, it is possible to maintain good leveling properties, thereby providing a good matte finish, excellent leveling properties, and suppressing the occurrence of cracking and chipping. However, the present invention is not limited to this inference. [Modes for carrying out the invention]

[0010] The curable artificial nail composition of the present invention is described below.

[0011] [(A) Compounds having a (meth)acryloyl group] (A) Compounds having a (meth)acryloyl group that are components of the curable artificial nail composition of the present invention include one or more selected from the group consisting of (meth)acrylate oligomers and (meth)acrylate monomers. In this specification, "(meth)acrylate oligomer" refers to acrylate oligomers and methacrylate oligomers, and "(meth)acrylate monomer" refers to acrylate monomers and methacrylate monomers.

[0012] <(meth)acrylate oligomer> The (meth)acrylate oligomer is not particularly limited as long as it is an oligomer having one or more (meth)acryloyl groups. The number of (meth)acryloyl groups contained in one molecule is not particularly limited, but from the viewpoint of curability of the curable artificial nail composition and hardness of the cured coating film, it is 1 to 10, preferably 2 to 8. The number of (meth)acryloyl groups can be determined by analysis using methods such as infrared absorption spectroscopy (IR), nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC / MS). The weight-average molecular weight of the (meth)acrylate oligomer is not particularly limited. For example, it may be 1,000 or more, preferably 2,000 or more, more preferably 3,000 or more, and for example, 100,000 or less, preferably 50,000 or less, and more preferably 35,000 or less. By setting the weight-average molecular weight within this range, it is possible to improve the durability of the cured coating film while maintaining low viscosity.

[0013] (Meth)acrylate oligomers are not particularly limited, but for example, (i) A (meth)acrylate oligomer having one or more selected from the group consisting of urethane bonds, bonds formed by ring-opening reaction of epoxy groups, ester bonds, ether bonds, urea bonds, carbonate bonds, and amide bonds in the main skeleton (main chain); (ii) A (meth)acrylate oligomer having a molecular chain formed by polymerization of one or more monomers selected from the group consisting of styrene-based, (meth)acrylic-based, olefin-based, and diene-based monomers in the main skeleton (main chain), etc. One or more selected from the group consisting of are mentioned. Among these, when one or more selected from the group consisting of urethane (meth)acrylate oligomers (meth)acrylate oligomers having a urethane bond in the main skeleton), epoxy (meth)acrylate oligomers having a molecular chain formed by ring-opening reaction of epoxy groups, ester (meth)acrylate oligomers (meth)acrylate oligomers having an ester bond in the main skeleton), ether (meth)acrylate oligomers (meth)acrylate oligomers having an ether bond in the main skeleton), etc. are used, it is advantageous in terms of adhesion and the like. (Meth)acrylate oligomers may be either commercially available products or synthetic products. Also, in the present invention, from the viewpoints of adhesion, durability, etc. of the curable artificial nail composition and / or its cured coating film, it is preferable to contain one or more urethane (meth)acrylate oligomers.

[0014] Urethane (meth)acrylate oligomers can be synthesized, for example, by reacting a polyol and a polyisocyanate to form an isocyanate group- or hydroxyl group-containing urethane prepolymer, and reacting the isocyanate group- or hydroxyl group-containing urethane prepolymer with a compound having an active hydrogen-containing group and a (meth)acryloyl group in the molecule (hydroxyalkyl (meth)acrylate, (meth)acrylic acid, etc.) or a compound having an isocyanate group and a (meth)acryloyl group in the molecule, but is not limited to this method.

[0015] When a urethane (meth)acrylate oligomer is used in the curable artificial nail composition, a cured coating film excellent in stretchability, adhesion, and strength can be obtained. One or more urethane (meth)acrylate oligomers that can be used in the present invention can be selected from those having one or more selected from the group consisting of a polyether skeleton, a polycarbonate skeleton, a polyester skeleton, an acrylic skeleton, and a polyolefin skeleton. Among them, those having one or more of a polyether skeleton and a polycarbonate skeleton are preferable.

[0016] For example, a urethane (meth)acrylate oligomer having one or more polyether skeletons is obtained by reacting a polyether polyol such as polypropylene polyol with a polyisocyanate such as isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, their isocyanurate compounds, biuret compounds, etc. to obtain an isocyanate group-containing polyether urethane prepolymer, and adding a (meth)acrylic compound having a hydroxyl group such as hydroxyethyl (meth)acrylate, and subjecting the isocyanate groups in the urethane prepolymer to an addition reaction with the (meth)acrylic compound having the hydroxyl group such that the amount of added (meth)acrylic compound is 10% or more of the total number of isocyanate groups in the urethane prepolymer.

[0017] Commercially available products may be used as the urethane (meth)acrylate oligomer. Examples of commercially available products include, but are not limited to, one or more selected from the group consisting of AH-600, AT-600, UA-306H, UF-8001G (manufactured by Kyoeisha Chemical Co., Ltd.), RUA-071, RUA-003VE, RUA-075, RUA-048 (manufactured by Asia Chemical Industry Co., Ltd.), SUA TH1, SUA 2 (manufactured by KSM Co., Ltd.), UV-3310B (manufactured by Mitsubishi Chemical Corporation), UN-9000PEP, UN-9200A (manufactured by Negami Industries Co., Ltd.), AU-2040 (manufactured by Tokushiki Co., Ltd.), KUA-PC2I (manufactured by KSM Co., Ltd.), etc.

[0018] An epoxy (meth)acrylate oligomer having a molecular chain formed by a ring-opening reaction of an epoxy group can be synthesized, for example, by reacting a polyfunctional epoxy resin with a (meth)acrylate having a functional group that reacts with an epoxy group, but is not limited to this method. Examples of commercially available products include, but are not limited to, one or more selected from the group consisting of EBECRYL 1259, 605, 1606 (manufactured by Daicel-Scytec), EPOXY ESTER 3000A, 3000MK, 3002A(N), 3002M(N), 40EM (manufactured by Kyoeisha Chemical Co., Ltd.).

[0019] Ester (meth)acrylate oligomers having ester bonds can be synthesized, for example, by adding a compound having a hydroxyl group and a (meth)acryloyl group, and / or an acrylic compound having a (meth)acrylic acid or a carboxyl group, to the carboxyl group and / or hydroxyl group of an ester oligomer obtained by the reaction of a polyol and a polycarboxylic acid, but the method is not limited to this. Commercially available products include, but are not limited to, one or more types selected from the group consisting of, for example, Aronics® M-6100, M-6200, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, M-9050 (manufactured by Toagosei Co., Ltd.) and UV-3500BA, UV-3520TL, UV-3200B, UV-3000B (manufactured by Mitsubishi Chemical Corporation).

[0020] Ether (meth)acrylate oligomers having an ether linkage can be synthesized, for example, by adding one or more compounds selected from the group consisting of compounds having a hydroxyl group and a (meth)acryloyl group in the molecule, (meth)acrylic acid, and compounds having a carboxyl group and a (meth)acryloyl group in the molecule to the hydroxyl group of an aliphatic polyether polyol or the hydroxyl group of an aromatic polyether polyol derived from bisphenol, etc., but the method is not limited to this method. Examples of commercially available products include, but are not limited to, one or more selected from the group consisting of UV-6640B, UV-6100B, UV-3700B (manufactured by Mitsubishi Chemical Corporation), Light Acrylate® 3EG-A, 4EG-A, 9EG-A, 14EG-A, PTMGA-250, BP-4EA, BP-4PA, BP-10EA, Light Ester 4EG, 9EG, 14EG (manufactured by Kyoeisha Chemical Co., Ltd.), EBECRYL® 3700 (manufactured by Daicel-Scytec Corporation), etc.

[0021] <(meth)acrylate monomer> The (meth)acrylate monomer is not particularly limited as long as it is a monomer having one or more (meth)acryloyl groups. The number of (meth)acryloyl groups contained in one molecule is not particularly limited, but from the viewpoint of curability of the curable artificial nail composition and hardness of the cured coating film, it is 1 to 10, preferably 1 to 8, and more preferably 1 to 6. In the present invention, it is preferable to use one or more (meth)acrylate monomers selected from those having one (meth)acryloyl group as the (meth)acrylate monomer. Alternatively, a mixture of one or more (meth)acrylate monomers having one (meth)acryloyl group and one or more (meth)acrylate monomers having two or more (meth)acryloyl groups may be used.

[0022] Examples of (meth)acrylate monomers having one (meth)acryloyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, adamantyl ( Esters of monohydric alcohols such as meth)acrylate and benzyl(meth)acrylate with (meth)acrylic acid; acrylamide, hydroxyethylacrylamide, dimethylacrylamide, diethylacrylamide, methacrylamide, N-methyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N,N-diisobutyl(meth)acrylamide, N,N-di-tert-butyl(meth)acrylamide, N,N-diheptyl(meth)acrylamide, N,N-dioctyl(meth)acrylamide, N,N-di-tert-octyl(meth)acrylamide, N,N-didodecyl(meth)acrylamide, N,N-dioctadecyl(meth)acrylamide (meth)acryloyl group-containing amide compounds such as N,N-dimethylaminopropyl(meth)acrylamide and N,N-dimethylaminoethyl(meth)acrylamide; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, and hydroxybutyl(meth)acrylate; nitrogen-containing alkyl(meth)acrylates such as N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, and Nt-butylaminoethyl(meth)acrylate;Glycidyl (meth)acrylate, 4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane, (2-methyl-2-ethyl-1,3-dioxolane-4yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-isobutyl-2-methyl-1,3-dioxolane-4yl)methyl (meth)acrylate, (2-ethyl-2-methyl-1,3-dioxolane-4yl)methyl (meth)acrylate, (1,4-dioxaspiro[4,5]decane-2yl)methyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate One or more types selected from the group consisting of heterocyclic (meth)acrylates such as alkoxylated tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, pentamethylpiperidyl (meth)acrylate, di(meth)acrylate isocyanurate, tri(meth)acrylate isocyanurate, triazine tri(meth)acrylate, N-(meth)acrylooxysuccinimide, and N-(meth)acrylooxyphthalimide are examples of such compounds.

[0023] Among these (meth)acrylate monomers having one (meth)acryloyl group, linear or branched alkyl-containing (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate; cyclic alkyl-containing methacrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate; hydroxyethylacrylamide, dimethylacrylamide, diethylacrylamide, N-methyl (meth)acrylamide Preferably, one or more compounds selected from the group consisting of (meth)acryloyl group-containing amide compounds such as N-hydroxyethyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, and N,N-dimethylaminoethyl (meth)acrylamide; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; and heterocyclic (meth)acrylates such as (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, and tetrahydrofurfuryl (meth)acrylate.

[0024] Examples of (meth)acrylate monomers having two or more (meth)acryloyl groups include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, ethoxylated propylene glycol di(meth)acrylate, and 1,3-butanediol. Di(meth)acrylate, 1,4-butanediol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate (isopyridene diphenyl bis(methacrylate) Di(meth)acrylate monomers such as oxyhydroxypropyl acid, propoxylated ethoxylated bisphenol A di(meth)acrylate; glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ε-caprolactone modified tris(acryloxyethyl) isocyanurate, and other tri(meth)acrylate monomers; tetra(meth)acrylate such as pentaerythritol tetra(meth)acrylate. One or more types selected from the group consisting of: acrylate monomers; polypentaerythritol (meth)acrylates such as dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol (meth)acrylate, tetrapentaerythritol (meth)acrylate, ethoxylated isocyanuric acid triacrylate, ethoxylated pentaerythritol tetraacrylate, etc., and (meth)acrylate monomers having four or more (meth)acrylate groups.

[0025] It is preferable to use one or more (meth)acrylate monomers having two or more (meth)acryloyl groups, selected from the group consisting of ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, propoxylated bisphenol A dimethacrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.

[0026] The content of the compound having (A)(meth)acryloyl group in the total amount of the curable artificial nail composition, when considered as 100% by mass, is, for example, 20.0% by mass or more, preferably 40.0% by mass or more, more preferably 50.0% by mass or more, and even more preferably 60.0% by mass or more, for example, 88.8% by mass or less, preferably 80.0% by mass or less, more preferably 75.0% by mass or less, and even more preferably 70.0% by mass or less.

[0027] In the present invention, it is preferable to use a mixture of (meth)acrylate oligomer and (meth)acrylate monomer as the compound having a (meth)acryloyl group (A). The content of (meth)acrylate oligomers in the total curable artificial nail composition, when the total amount is 100% by mass, is, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, and for example, 70% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less. If the (meth)acrylate oligomer content is less than 5% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too low. If the (meth)acrylate oligomer content exceeds 70% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too high. The content of (meth)acrylate monomer in the total amount of the curable artificial nail composition, when considered as 100% by mass, is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 70% by mass or less, preferably 65% ​​by mass or less, and more preferably 60% by mass or less. If the (meth)acrylate monomer content is less than 10% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too high. If the (meth)acrylate oligomer content exceeds 70% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too low.

[0028] [(B) Polymerization initiator] The polymerization initiator (B), which is a component of the curable artificial nail composition of the present invention, is not particularly limited as long as it generates radicals when energy is applied by light (e.g., ultraviolet light) or heat irradiation, and can initiate the polymerization of the compound having the (A) (meth)acryloyl group. For example, one or more polymerization initiators selected from the group consisting of acylphosphine oxide, α-hydroxyalkylphenone, benzoin ether, benzyl ketal, acid ester, α-aminoalkylphenone, benzophenone, thioxanthone, titanocene, quinone, peroxide, azo, persulfate, etc. For example, by using a photopolymerization initiator, good curability can be imparted to a curable artificial nail composition even when irradiated with light using various light sources, including UV-LED light sources.

[0029] For example, acylphosphine oxide polymerization initiators generate radicals when irradiated with ultraviolet light of a wavelength of 365-405 nm emitted from commonly used UV-LED light sources. Therefore, even when curing by irradiation with light using various light sources, including UV-LED light sources, good curability can be imparted to the curable composition. Furthermore, when curing by irradiation with light using a UV-LED light source, yellowing of the cured coating film can be prevented. Examples of acylphosphine oxide polymerization initiators include one or more selected from the group consisting of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. In particular, 2,4,6-trimethylbenzoyldiphenylphosphine oxide can be preferably used in the present invention because it also functions as a skin conditioning agent.

[0030] Examples of polymerization initiators other than acylphosphine oxide-based polymerization initiators include 1-hydroxycyclohexylphenyl ketone (IRGACURE184), 1-(4-(phenylthio)-2,2-(O-benzoyloxime))1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, 2-H Droxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-propylthioxanthone, 3-[3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl-o [Xyxy]-2-hydroxypropyl-N,N,N-trimethylammonium chloride, fluorothioxanthone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), 4-benzoyl-4'-methyl-diphenyl sulfide, 1,2-octanedione, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino Propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropane, isophthalphenone, methyl phenylglyoxyate, butylanthraquinone, ethylanthraquinone, phenanthrenequinone, camphorquinone, benzophenone, 4-phenylbenzophenone, benzoylbenzoic acid, hydroxybenzophenone, 4,4'-Bis(diethylamino)benzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2' -Azobis(2-amidinopropane) dihydrochloride, 2,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobis(isobutyronitrile), 2,2'-Azobis-2-methylbutyronitrile, 1,1-Azobis(1-cyclohexanecarbonitride), 2,2'-Azobis(2-methylpropionitrile), 2,2'-Azobis(2-cyclopropylpropionitrile), 2,2'-Azobis(methylisobutyrate), t-butyl hydroperoxide, cumene hydroperoxide, diacetyl peroxide, didecanoyl peroxide Di-t-butyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, dicumyl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, 2,5-dimethylhexane-2,5-dihydroperoxide, dilauroyl peroxide, disaxinic acid peroxide, dibenzoyl peroxide, parachlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, t-butyl peroxybenzoate, t-hexyl peroxide Side valerate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, n-butyl-4,4-di(t-butylperoxy)valerate, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,One or more substances selected from the group consisting of 1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, dicetyl peroxydicarbonate, t-hexylperoxyisopropyl monocarbonate, diisopropyl peroxydicarbonate, t-butylperoxyisopropyl carbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, potassium persulfate, sodium persulfate, ammonium persulfate, etc.

[0031] In the curable artificial nail composition of the present invention, it is preferable to use a polymerization initiator that can generate radicals and initiate polymerization at ultraviolet wavelengths of approximately 405 nm and 365 nm irradiated during curing, and it is more preferable to use a polymerization initiator containing an acylphosphine oxide-based polymerization initiator. In addition, a polymerization initiator containing an α-hydroxyalkylphenone-based polymerization initiator may be used, and a polymerization initiator composition containing an acylphosphine oxide-based polymerization initiator and a peroxide-based polymerization initiator may also be used.

[0032] In the curable artificial nail composition of the present invention, the content of (B) polymerization initiator is, for example, 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on 100% by mass of the total amount of the curable artificial nail composition, for example, 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less. If the content of (B) polymerization initiator exceeds 15.0% by mass, the cured coating film of the curable artificial nail composition may become brittle or yellow. If the content of (B) polymerization initiator is less than 0.05% by mass, the curing of the curable artificial nail composition may take a long time, and curing may be incomplete.

[0033] In the curable artificial nail composition of the present invention, when a polymerization initiator containing an acylphosphine oxide polymerization initiator and an α-hydroxyalkylphenone polymerization initiator is used as the polymerization initiator (B), the content of the acylphosphine oxide polymerization initiator is, for example, 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more, based on 100% by mass of the total amount of the curable artificial nail composition; the content of the α-hydroxyalkylphenone polymerization initiator is, for example, 1.0% by mass or more, preferably 2.0% by mass or more, and more preferably 3.0% by mass or more, based on 100% by mass of the total amount of the curable artificial nail composition, for example, 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less; and the total content of the acylphosphine oxide polymerization initiator and the α-hydroxyalkylphenone polymerization initiator is, for example, 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less. If the content of acylphosphine oxide polymerization initiator exceeds 12.0% by mass, the cured coating of the curable artificial nail composition may become brittle or yellow. If the content of acylphosphine oxide polymerization initiator is less than 0.05% by mass, the curing heat of the curable artificial nail composition may increase, and the temperature rise during curing may become large.

[0034] [(C) Polyurethane resin particles with a volume-average particle diameter of 3 μm or more and 30 μm or less] The polyurethane resin particles (C), which are components of the curable artificial nail composition of the present invention and have a volume-average particle diameter of 3 μm or more and 30 μm or less, are polyurethane resin particles obtained by reacting at least a polyol with a polyisocyanate, and are not particularly limited as long as the volume-average particle diameter is 3 μm or more and 30 μm or less. When obtaining the polyurethane resin that constitutes the polyurethane resin particles, chain extenders, crosslinking agents, and catalysts can be used as needed.

[0035] The polyol constituting the polyurethane resin particles may be a polymer polyol or a low molecular weight polyol. The polymer polyol is not particularly limited as long as it is a compound having a number-average molecular weight of 400 or more and two or more hydroxyl groups. For example, one or more types selected from the group consisting of polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, polyurethane polyols, etc. Low molecular weight polyols are not particularly limited as long as they are compounds with a number-average molecular weight of less than 400 and have two or more hydroxyl groups.For example, ethylene glycol, 1,2- or 1,3-propanediol, 1,2- or 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-propanediol, 2-n-propyl-1,3-propanediol, 2-isopropyl- 1,3-propanediol, 2-n-butyl-1,3-propanediol, 2-isobutyl-1,3-propanediol, 2-tert-butyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-propyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-3-ethyl-1,4-butanediol, 2-methyl-3-ethyl-1,4-butanediol, 2,3-diethyl 1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2,3,4-triethyl-1,5-pentanediol, dimer acid diol, alkylene oxide adduct of bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, p-xylylene glycol, bis(2-hydroxyethyl) terephthalate, bis(2-hydroxyethyl) isophthalate, 1,4-bis(2-hydroxyethoxy)benzene, 1,3-bis(2-hydroxyethoxy)benzene, resorci One or more polyols selected from the group consisting of divalent polyols such as nitrate, hydroquinone, 2,2'-bis(4-hydroxycyclohexyl)propane, 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, bisphenol F, and bisphenol A; and trivalent or higher polyols such as glycerin, trimethylolpropane, tetramethylolmethane, pentaerythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, and D-mannitol.

[0036] Polyisocyanates that constitute polyurethane resin particles include, for example, aliphatic diisocyanates such as hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, decamethylene diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate; xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, and tetramethylxylylene diisocyanate. One or more types selected from the group consisting of aromatic aliphatic diisocyanates such as t; alicyclic diisocyanates such as isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylene diisocyanate; trimers, allophanates, biuret compounds, dimer compounds, dimer-trimer compounds, carbodiimides, uretonimines, and adducts of these isocyanates.

[0037] In the present invention, polyurethane resin particles obtained by reacting a polymer polyol with an isocyanate selected from aliphatic, aromatic aliphatic, and alicyclic compounds are preferred, and in particular, polyurethane resin particles obtained by reacting a polyol containing a polyester polyol (e.g., trimethylol hexyllactone polyol) with a diisocyanate such as hexamethylene diisocyanate, isophorone diisocyanate, or hydrogenated diphenylmethane diisocyanate are preferred. Commercially available polyurethane resin particles can be used for this purpose. Examples of commercially available products include one or more types from the Art Pearl series (manufactured by Negami Kogyo Co., Ltd., C-800T, C-600T, C-400T, C-300T, etc.) and the Dymic Beads series (manufactured by Dainichi Seika Kogyo Co., Ltd., CM-1157, CM-1077, etc.).

[0038] The volume-average particle diameter of the polyurethane resin particles is not particularly limited, as long as it is between 3 μm and 30 μm. This makes it possible to form a cured coating film of the curable artificial nail composition that has excellent design qualities, a rich low gloss, and is resistant to cracking and chipping. The volume-average particle diameter of the polyurethane resin particles is preferably 4 μm or more, more preferably 5 μm or more, preferably 27 μm or less, and more preferably 25 μm or less.

[0039] In the curable artificial nail composition, the content of (C) polyurethane resin particles having a volume average particle diameter of 3 μm or more and 30 μm or less is 15 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the compound having (meth)acryloyl groups. Preferably it is 90 parts by mass or less, and more preferably 85 parts by mass or less. If the content of polyurethane resin particles exceeds 95 parts by mass per 100 parts by mass of the compound having (meth)acryloyl groups, the curable artificial nail composition becomes thicker and its leveling properties decrease, and if it is less than 15 parts by mass, it is not possible to impart sufficient matte finish to the cured coating film.

[0040] [(D) Other ingredients] In addition to (A) to (C) above, various other components may be added to the curable artificial nail composition of the present invention as "(D) other components" within a range that does not adversely affect the glossiness of the cured coating film, the matte finish of the cured coating film, the durability of the cured coating film, the adhesive viscosity of the cured coating film, the handling properties, the storage stability, the applicability, the curability, etc. of the cured coating film. (D) Other components include, for example, one or more additives selected from the group consisting of radical polymerizable compounds other than the compounds having an acryloyl group in (A), resins other than those in (A) and (C), colorants, polyfunctional thiol compounds, polyol compounds, polymerization inhibitors, solvents, fragrances, silicone-based and fluorine-based defoamers, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, photopolymerization accelerators such as tertiary amines, chain transfer agents, surface tension modifiers, flame retardants, antioxidants, ion adsorbents, stress reducers, preservatives, antibacterial agents, flexibility imparters, waxes, halogen traps, leveling agents, wetting improvers, decorative materials, and various other additives.

[0041] Radical polymerizable compounds other than (meth)acryloyl group-containing polymerizable compounds are not particularly limited. For example, one or more selected from the group consisting of vinyl group-containing compounds, allyl group-containing compounds, etc. Specifically, one or more selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, vinyl acetate, vinyl propionate, methyl vinyl ether, ethyl vinyl ether, N-vinylpyrrolidone, vinylpyridine, allyl glycidyl ether, vinyl group-containing oligomers, allyl group-containing oligomers, etc.

[0042] The resin is not particularly limited, as long as it is neither polymerizable nor a polyol compound. For example, one or more resins selected from the group consisting of polyurethane resins, polyester resins, polyamide resins, polyether resins, olefin resins, aromatic olefin resins, aromatic hydrocarbon resins, acrylic resins, vinyl chloride resins, vinyl acetate resins, polyvinyl alcohol resins, polyvinyl acetal resins, core-shell polymers, graft resins, block resins, etc.

[0043] The coloring agent is one or more selected from the group consisting of pigments, luminescent agents, and dyes, and is used in any amount to impart a desired color tone to the curable artificial nail composition. In particular, it is one or more selected from the group consisting of inorganic pigments, luminescent agents, organic pigments, and dyes used in nail coating materials, and does not significantly inhibit curing by ultraviolet irradiation (light irradiation), etc. The curable artificial nail composition before hardening can also contain not only pigments, but also resin particles and decorative materials that can be incorporated into known curable artificial nail compositions.

[0044] Examples of colorants include Brown No. 201, Black No. 401, Purple No. 201, Purple No. 401, Blue No. 1, Blue No. 2, Blue No. 201, Blue No. 202, Blue No. 203, Blue No. 204, Blue No. 205, Blue No. 403, Blue No. 404, Green No. 201, Green No. 202, Green No. 204, Green No. 205, Green No. 3, Green No. 401, Green No. 402, Yellow No. 201, Yellow No. 202-(1), Yellow No. 20 No. 2-(2), Yellow No. 203, Yellow No. 204, Yellow No. 205, Yellow No. 4, Yellow No. 401, Yellow No. 402, Yellow No. 403-(1), Yellow No. 404, Yellow No. 405, Yellow No. 406, Orange 201 No., Orange No. 203, Orange No. 204, Orange No. 205, Orange No. 206, Orange No. 207, Orange No. 401, Orange No. 402, Orange No. 403, Red No. 102, Red No. 104-(1), Red No. 105-(1 ), Red No. 106, Red No. 2, Red No. 201, Red No. 202, Red No. 203, Red No. 204, Red No. 205, Red No. 206, Red No. 207, Red No. 208, Red No. 213, Red No. 214, Red No. 215, Red No. 218, Red No. 219, Red No. 220, Red No. 221, Red No. 223, Red No. 225, Red No. 226, Red No. 227, Red No. 228, Red No. 230-(1), Red No. 23 One or more types selected from the group consisting of 0-(2), Red No. 231, Red No. 232, Red No. 3, Red No. 401, Red No. 405, Red No. 501, Red No. 502, Red No. 503, Red No. 504, Red No. 505, Red No. 506, titanium dioxide, iron oxide, chromium oxide, manganese violet, carbon black, metal powder, metal flakes, metal oxide flakes, glass flakes, etc.

[0045] Polyfunctional thiol compounds are incorporated into curable artificial nail compositions as curing modifiers, crosslinking agents, and viscosity modifiers. Furthermore, incorporating polyfunctional thiol compounds into curable artificial nail compositions can improve the wipeability when removing the cured coating film. Examples of polyfunctional thiol compounds include those obtained by reacting a thiol group or a compound having a group that reacts to form a thiol group with the hydroxyl group of a polyol compound such as trimethylolpropane, pentaerythritol, or dipentaerythritol. For example, one or more compounds selected from the group consisting of trimethylolpropane tris(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), etc. When a polyfunctional thiol compound is included in a curable artificial nail composition, it is preferably included in an amount of 1.0 to 10.0% by mass.

[0046] Polyol compounds function as diluents and adhesion enhancers for curable artificial nail compositions. Examples of polyol compounds include one or more selected from the group consisting of alkyl polyols, polyester polyols, polyether polyols, acrylic polyols, polybutadiene polyols, and phenolic polyols. Among these, alkyl polyols, polyester polyols, and polyether polyols are preferred. Examples of alkyl polyols include one or more selected from the group consisting of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, cyclohexanedimethanol, trimethylolpropane, pentaerythritol, and the like.

[0047] Examples of polyester polyols include one or more selected from the group consisting of condensation-type polyester polyols, addition-polymerized polyester polyols, and polycarbonate polyols. Condensation-type polyester polyols are obtained by a condensation reaction between one or more diol compounds selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1,4-hexanedimethanol, dimer acid diol, polyethylene glycol, etc., and one or more organic polybasic acids selected from the group consisting of adipic acid, isophthalic acid, terephthalic acid, sebacic acid, etc., and a molecular weight of 100 to 100,000 is preferred. Examples of addition-polymerized polyester polyols include polycaprolactone, and a molecular weight of 100 to 100,000 is preferred. Polycarbonate polyols are synthesized by methods such as direct phosgenation of polyols or transesterification with diphenyl carbonate, and their molecular weight is preferably 100 to 100,000. Examples of polyether polyols include polyether polyols obtained by ring-opening polymerization of alkylene oxides.

[0048] Polymerization inhibitors include, for example, one or more selected from the group consisting of quinone compounds, salicylic acid hydrazide, tocopherol compounds, and the like. When a polymerization inhibitor is included in the curable artificial nail composition, it can be blended in an amount of 500 to 5000 ppm, preferably 1000 to 4500 ppm, relative to the total amount of the curable artificial nail composition.

[0049] The solvent is not particularly limited as long as its viscosity during application can be adjusted by dilution. Examples include alcohols such as methanol, ethanol, propanol, n-butanol, and i-butanol; ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; cellosolves such as ethyl cellosolve; aromatic hydrocarbons such as toluene and xylene; glycol ethers such as propylene glycol monomethyl ether; acetic acid esters such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol, among others.

[0050] [Viscosity of hardened artificial nail compositions] The curable artificial nail composition of the present invention can have a viscosity at 25°C of, for example, 0.1 Pa·s to 60.0 Pa·s. Preferably, it is 0.5 Pa·s or more, more preferably 0.7 Pa·s or more, preferably 50.0 Pa·s or less, and more preferably 40.0 Pa·s or less. By having a viscosity in this range, a curable artificial nail composition can be made that has excellent applicability with applicators such as brushes and inkjet printers.

[0051] [Uses of hardening artificial nail compositions] The curable artificial nail composition of the present invention is a composition for coating the surface of the nail, similar to so-called general manicures and pedicures. The curable artificial nail composition of the present invention has excellent leveling properties, enabling the formation of a smooth cured coating film. The moderate hardness of the cured coating film suppresses the occurrence of cracking, and the cured coating film has practical adhesion to substrates and coating film durability. When forming the cured coating film of the curable artificial nail composition of the present invention, equipment similar to that used for curing radical polymerizable curable compositions, such as general ultraviolet curing equipment or nail polish curing equipment, can be used.

[0052] The curable artificial nail composition of the present invention is particularly suitable for use as gel nails. For example, when used to form a base coat layer applied directly to the user's nail, a color coat layer applied on top of the base coat layer, or a top coat layer applied on top of the top coat, the cured coating film will not chip or peel off for a long period of time (for example, at least two weeks after curing), and lifting from the underlying layer or the user's nail can be suppressed. When used as a color coat layer, a variety of colors such as solid colors, glittery colors, metallic colors, dark colors, and light colors can be mixed using colorants. Furthermore, regardless of which layer the curable artificial nail composition of the present invention is used in, the cured coating film will not chip or peel off for a long period of time (for example, at least two weeks after curing), and lifting from the underlying layer or the user's nail will be suppressed.

[0053] The curable artificial nail composition of the present invention has a gloss value of less than 40 and can form a cured coating film with low gloss and excellent matte finish, making it suitable for use in forming the top coat layer of gel nails. In particular, it can be suitably used as a clear top coat, a glittery clear top coat containing luminous materials such as metal powder, metal flakes, metal oxide flakes, and glass flakes, or a color coat layer colored using a desired coloring agent. Furthermore, after applying the curable artificial nail composition of the present invention, it is possible to enhance its design by attaching small decorations or powders to the surface of the coating film of the curable artificial nail composition before it hardens.

[0054] [Covering of nails using a hardening artificial nail composition] The nails coated with the curable composition of the present invention may be human fingernails or toenails, or even animal nails such as those of dogs or cats. When applying the curable artificial nail composition of the present invention to a nail or an (uncured) coating applied to a nail, sanding of the application surface is optional. The method of applying the curable artificial nail composition is not particularly limited, and for example, an application tool such as a brush or an application method such as inkjet printing can be used.

[0055] Using the curable artificial nail composition of the present invention, an uncured coating layer having the shape of a nail or the like can be prepared on at least one surface of a sheet, and after bringing this layer into contact with (transferring) the nail surface, the sheet can be peeled off or cured by irradiation with ultraviolet light without peeling it off. By applying an uncured coating layer to the sheet surface using a curable artificial nail composition beforehand and then transferring it, it is possible to cover the nail surface with a uniform and accurate pattern without using application tools such as brushes, and there is no need to clean the application tools after use.

[0056] The means for curing the curable artificial nail composition after application is not particularly limited, as long as it is a means capable of supplying the energy necessary to cause the curable artificial nail composition to harden. Examples include irradiation with energy rays such as light (ultraviolet (UV)), electron beams, and heat. In particular, curing by ultraviolet (UV) irradiation is preferable because it can be performed relatively quickly and easily. When curing by irradiation with light such as ultraviolet light, a known ultraviolet curing device can be used. Although the amount of energy required for curing differs depending on the composition of the curable artificial nail composition, for example, when curing by irradiation with light such as ultraviolet light, the irradiation energy (integrated light amount) by light irradiation is, for example, 5 mJ / cm². 2 Preferably 10 mJ / cm² 2 That's all, for example, 1000 mJ / cm 2 Preferably 800 mJ / cm² 2 The following applies: If the irradiation energy is within this range, nail art with sufficient adhesion and abrasion resistance can be obtained. As a light source for irradiation, known ultraviolet light sources such as mercury lamps, metal halide lamps, ultraviolet light-emitting diodes (UV-LEDs), and ultraviolet laser diodes (UV-LDs) can be used. Among these, ultraviolet light-emitting diodes (UV-LEDs; wavelength 385-415 nm; peak wavelength approximately 405 nm) and ultraviolet laser diodes (UV-LDs) are preferred from the viewpoint of small size, long lifespan, high efficiency, and low cost. [Examples]

[0057] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "mass%" and "parts" means "parts by mass".

[0058] [Examples 1-7, Comparative Examples 1-9] The components shown in Tables 1 and 2 were added to a container in the proportions (parts by mass) shown in Tables 1 and 2, and the mixture was heated to 50°C while stirring with a dissolver. Degas the mixture for 10 minutes under a pressure of 0.1 MPa while stirring. After stirring, let it stand at 80°C for 2 hours to remove air bubbles. A curable artificial nail composition was obtained. All of these steps were carried out under light-shielding conditions.

[0059] <Ingredients> The components in Tables 1 and 2 are as follows: UA: Polyurethane methacrylate obtained from hydroxyethyl methacrylate, isophorone diisocyanate, and polypropylene glycol (weight-average molecular weight 4,000) IBXA: Isobornyl acrylate TPO:2,4,6-trimethylbenzoyldiphenylphosphine oxide PU Particle 1: Polyurethane resin particles (average particle size 22 μm) PU particles 2: Polyurethane resin particles (average particle size 15 μm) PU particles 3: Polyurethane resin particles (average particle size 6 μm) PU particles 4: Polyurethane resin particles (average particle size 7 μm) PU particles 5: Polyurethane resin particles (average particle size 50 μm) PU particles 6: Polyurethane resin particles (average particle size 32 μm) Ac Particle 1: Acrylic resin particles (average particle size 6 μm) Ac Particles 2: Acrylic resin particles (average particle size 5 μm) Ac Particles 3: Acrylic resin particles (average particle size 8 μm)

[0060] <Glossiness (GU)> The obtained curable artificial nail composition was applied to a rigid polyvinyl chloride board to form a coating film with a thickness of 100 μm, and cured by irradiation with a 30W LED lamp (irradiation wavelength 405 nm) for 30 seconds. After wiping off the uncured components from the resulting cured coating film with an 80% ethanol aqueous solution, the rigid polyvinyl chloride board was placed on black drawing paper, and the gloss value was determined using a gloss checker (Horiba, Ltd., IG-310). The results are shown in Tables 1 and 2.

[0061] <Matte finish evaluation> Based on the obtained gloss (GU) values, the matte finish was evaluated according to the following criteria. In this invention, A is a pass and C is a fail. A: Glossiness (GU) is less than 40 GU. C: Glossiness (GU) of 40 GU or higher.

[0062] <Cracked paint film> The obtained curable artificial nail composition was applied to a polypropylene film to form a coating, and cured by irradiating it with a 30W LED lamp (irradiation wavelength 405nm) for 30 seconds to produce a cured coating with a thickness of 200 μm and dimensions of 1 cm x 5 cm. After wiping off the uncured components from the obtained cured coating with an 80% ethanol aqueous solution, the cured coating was peeled off the polypropylene film. The lateral ends of the peeled cured coating were overlapped, and a load of 500 gf was applied to the bent portion to visually check for the occurrence of coating cracks, and the coating cracks were evaluated according to the following criteria. In this invention, A is a pass and C is a fail. A: No cracks have occurred in the paint film. C: Cracks have occurred in the paint film.

[0063] <Leveling properties> 100 mg of the obtained curable artificial nail composition was taken and, using a brush for curable artificial nail compositions, was applied to a 1.5 cm x 1.5 cm square on a nylon plate four times vertically, four times horizontally, and then four more times vertically to form a coating film. After application, it was left to stand for 1 minute, and the condition of the coating film was visually checked and the leveling properties were evaluated according to the following criteria. In this invention, A is a pass and C is a fail. A: The paint film surface is smooth, making it impossible to identify any brushstrokes. C: Fine waves (brushstrokes) can be seen on the surface of the paint film.

[0064] [Table 1]

[0065] [Table 2]

[0066] As shown in Table 1, the curable artificial nail compositions of Examples 1 to 7 all formed a cured coating film with suppressed gloss and good matte properties, suppressed cracking of the cured coating film, and exhibited excellent leveling properties, making them suitable for use as gel nails, especially as top coat gel nails. On the other hand, as shown in Table 2, when polyurethane resin particles were not used (Comparative Example 1), when polyurethane resin particles with a particle size exceeding 30 μm were used (Comparative Examples 2 and 3), and when the amount of polyurethane resin particles was small (Comparative Example 4), the cured coating film of the curable resin composition had high gloss and poor matte finish. When the amount of polyurethane resin particles was large (Comparative Example 5), the leveling properties were poor and it was not possible to form a cured coating film suitable for gel nails. When acrylic resin particles were used instead of polyurethane resin particles, cracking of the coating film occurred in all cases, making it difficult to use them for gel nails, especially gel nails for top coats.

Claims

[Claim 1] (A) to (C) below; (A) Compounds having a (meth)acryloyl group, (B) Polymerization initiator, (C) Polyurethane resin particles with a volume-average particle diameter of 3 μm or more and 30 μm or less. It contains, With respect to 100 parts by mass of (A), the amount of (C) is 15 parts by mass or more and 95 parts by mass or less. Curable artificial nail composition.

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