Curable artificial nail composition

Abstract

To provide a curable artificial nail composition that is a non-wipe type, leaving no uncured components on the surface of a cured coating layer, has high storage stability, and has a contradictory characteristic of the non-wipe type and the storage stability.SOLUTION: A curable artificial nail composition contains (a) a (meth)acrylate compound, (b) a polyfunctional thiol compound, and (c) an α-hydroxyalkylphenone-based polymerization initiator. The (a) (meth)acrylate compound includes one or more polyurethane (meth)acrylate oligomers with six or more functional groups and a weight-average molecular weight of 1,500 or more to 5,000 or less. When the content of the (b) polyfunctional thiol compound relative to the total amount of the curable artificial nail composition is x mass%, and the content of the (c)α-hydroxyalkylphenone-based polymerization initiator relative to the total amount of the curable artificial nail composition is y mass%, the following relationships are satisfied: (α) 20.0≥x≥3.5; (β) 15.0≥y≥0.5; (γ) x+6y≥18.5; and (δ) 3x+y≥21.5.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Nail art, which involves decorating natural nails on the hands and feet or gluing artificial nails and then decorating them, is becoming increasingly popular. In addition, artificial nails are formed on top of the nails to reinforce them and prevent them from cracking or peeling off due to external forces. For such nail decoration or reinforcement, resin-containing materials, so-called manicures, pedicures, and sculptures, are applied to the nails.

[0003] Recently, a photocurable artificial nail composition called gel nail has been attracting attention as a material used for decorating or reinforcing nails. Gel nail is a photocurable gel-like nail coating material (photocurable artificial nail composition), and is known to contain, for example, a (meth)acrylate oligomer and a (meth)acrylic monomer. Gel nail is applied to the nail and cured by irradiating with ultraviolet light, forming a crosslinked polymer coating by radical polymerization reaction, which is said to form a tough coating that is difficult to peel off from the nail. A widely known type of gel nail is composed of three layers: a base coat layer applied on the nail, a color coat layer applied between the base coat layer and the top coat layer, and a top coat layer applied on the outermost surface.

[0004] The top coat layer of a gel nail is provided on the outermost surface, and is a layer that adjusts the design such as gloss and protects the gel nail. The top coat layer is formed as a cured coating film crosslinked by a radical polymerization reaction by applying a composition for forming a top coat layer containing a (meth)acrylate compound and curing it by irradiating it with energy rays such as ultraviolet rays. At that time, since uncured (meth)acrylate compounds remain, it was necessary to remove the uncured components by wiping the cured coating film with a solvent. For this reason, there has been an increasing need recently for a "non-wipe type" curable artificial nail composition for forming a gel nail top coat layer, which suppresses the generation of uncured components by using a composition for forming a top coat layer containing a chain transfer agent and has a curing reaction mechanism that is not easily inhibited by oxygen, and does not require wiping off the uncured components on the surface of the cured coating film after application.

[0005] The following are known as curable artificial nail compositions for forming a "non-wipe type" gel nail top coat layer. Patent Document 1 discloses an artificial nail raw material composition that contains (A) a radically polymerizable compound having one or more radically polymerizable unsaturated bonds in one molecule, (B) a polyfunctional thiol compound having two or more thiol groups in one molecule, and (C) a photopolymerization initiator. Patent Document 2 discloses a photocurable artificial nail composition that contains a urethane (meth)acrylate oligomer, a (meth)acrylate monomer, a polyfunctional thiol compound, a polymerization initiator, and a tocopherol compound, in which the content of the tocopherol compound is 1,000 ppm or more and 5,000 ppm or less. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-5260 A [Patent Document 2] Patent No. 6755544 Summary of the Invention [Problem to be solved by the invention]

[0007] It is known that a curable artificial nail composition for a "non-wipe type" gel nail top coat layer must use a thiol compound that induces a chain transfer reaction and a multifunctional (meth)acrylate compound that enhances reactivity. However, a curable artificial nail composition containing a thiol compound and a multifunctional (meth)acrylate compound forms a cured coating film by a chain transfer reaction, unlike the polymerization reaction of (meth)acrylate compounds by a normal chain reaction. In this chain transfer reaction, the thiol group receives and delivers the radicals, and when polymerization is initiated by irradiation with light, the polymerization reaction proceeds rapidly, and since the termination reaction is unlikely to occur, the polymerization reaction (curing reaction) continues gradually. This has the advantage of providing excellent surface curing properties for the coating film and leaving no uncured (meth)acrylate compound on the surface of the cured coating film, but it also has the disadvantage of making the storage stability of the gel nail composition in the container easily worse due to its reactivity.

[0008] In order to improve the storage stability of curable artificial nail compositions for gel nails, polymerization inhibitors have been added, but due to the polymerization inhibition (polymerization termination) function of the polymerization inhibitor, uncured (meth)acrylate compounds remain on the surface of the cured coating film, which may prevent the composition from being made into a non-wipe type. In addition, the amount of thiol compounds blended has been reduced as much as possible, but it is difficult to maintain a balance between non-wipe properties and storage stability, and no curable artificial nail composition that combines the contradictory properties of non-wipe properties and storage stability has been known until now. As a result of further investigations, the present inventors have discovered that in a non-wipe type curable artificial nail composition for gel nails, by containing a specific polyfunctional (meth)acrylate compound and by setting the content of the polyfunctional thiol compound and the blended amount of the α-hydroxyalkylphenone polymerization initiator in a specific relationship, a curable artificial nail composition that combines the contradictory properties of non-wipe type and storage stability can be obtained.

[0009] The problem to be solved by the present invention is to provide a curable artificial nail composition that is a non-wipe type in which no uncured components remain on the surface of the cured coating film, has good storage stability, and combines the contradictory properties of being a non-wipe type and having storage stability. [Means for solving the problem]

[0010] Means for Solving the Problems The present inventors have conducted extensive research to find that the above problems can be solved by providing a curable artificial nail composition having a specific composition, and have thus completed the present invention. Specifically, the following applies: [Section 1] (a) a (meth)acrylate compound, (b) a polyfunctional thiol compound, and (c) an α-hydroxyalkylphenone polymerization initiator, Contains The (a) (meth)acrylate compound includes at least one type of hexa- or higher-functional polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 or more and 5,000 or less, When the content of the (b) polyfunctional thiol compound relative to the total amount of the curable artificial nail composition is x mass %, and the content of the (c) α-hydroxyalkylphenone-based polymerization initiator relative to the total amount of the curable artificial nail composition is y mass %, the following relationship is satisfied; (α) 20.0 ≧ x ≧ 3.5 (β) 15.0 ≧ y ≧ 0.5 (γ)x+6y≧18.5 (δ)3x+y≧21.5 The present invention relates to a curable artificial nail composition. Effect of the Invention

[0011] The present invention exerts a remarkable effect in that it provides a curable artificial nail composition that is a non-wipe type in which no uncured components remain on the cured coating film surface and has good storage stability, thereby combining the contradictory properties of a non-wipe type and storage stability.

[0012] The mechanism by which the curable artificial nail composition of the present invention becomes a non-wipe type curable artificial nail composition in which no uncured components remain on the cured coating film surface and which has good storage stability is unclear, but the present inventors speculate as follows.

[0013] In general, when ultraviolet rays are irradiated onto an ultraviolet-curable coating film, it is said that a polymerization initiator having a peak absorption wavelength on the short wavelength side of the ultraviolet region contributes more to surface curing than a polymerization initiator having an absorption wavelength on the long wavelength side. In addition, as a property of ultraviolet rays, ultraviolet rays having a short wavelength tend to come into contact with a polymerization initiator near the surface and initiate a reaction, and therefore it is presumed to be advantageous in promoting the curing of the coating surface and reducing the amount of uncured components remaining on the coating surface. The α-hydroxyalkylphenone-based polymerization initiator contained in the curable artificial nail composition of the present invention corresponds to a polymerization initiator having a peak absorption wavelength on the short wavelength side of the ultraviolet region, and therefore is considered to promote the curing of the coating surface and reduce the amount of uncured components remaining on the coating surface. On the other hand, in order to make it a non-wipe type, it is essential to use a multifunctional (meth)acrylate compound that enhances reactivity and a multifunctional thiol compound that is a chain transfer agent that can react without being inhibited by oxygen. From this, it is presumed that a curable artificial nail composition that combines the contradictory properties of non-wipe type and storage stability can be obtained by containing a specific multifunctional (meth)acrylate compound and by setting the content of the multifunctional thiol compound and the blending amount of the α-hydroxyalkylphenone-based polymerization initiator in a specific relationship. However, the present invention is not limited to this presumption. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a graph showing the relationship between the content of (b) a polyfunctional thiol compound and the content of (c) an α-hydroxyalkylphenone-based polymerization initiator relative to the total amount of a curable artificial nail composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The curable artificial nail composition of the present invention will now be described.

[0016] [(a) (Meth)acrylate compound] The (a) (meth)acrylate compound, which is a component of the curable artificial nail composition of the present invention, is a compound that has one or more (meth)acryloyl groups in the molecule and can be cured by exposure to energy rays such as light. The (a) (meth)acrylate compound is not particularly limited as long as it contains at least one type of hexa- or higher-functional polyurethane (meth)acrylate oligomer having a weight-average molecular weight of 1,500 to 5,000. The (a) (meth)acrylate compound may contain at least one type selected from the group consisting of (meth)acrylate oligomers and (meth)acrylate monomers. In this specification, the term "(meth)acrylate oligomer" refers to an acrylate oligomer and a methacrylate oligomer, and the term "(meth)acrylate monomer" refers to an acrylate monomer and a methacrylate monomer.

[0017] <(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 and a plurality of repeating units in the molecule, and includes one or more types of polyurethane (meth)acrylate oligomers having 6 or more functionalities and a weight average molecular weight of 1,500 or more and 5,000 or less.

[0018] (Polyurethane (meth)acrylate oligomer with 6 or more functional groups and a weight average molecular weight of 1,500 to 5,000) A hexa- or higher functional polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 or more and 5,000 or less can be obtained, for example, by adding a hydroxyl group-containing (meth)acrylate compound to the isocyanate groups remaining in a polyurethane skeleton synthesized from a polyisocyanate component and a polyol component.

[0019] Examples of the polyisocyanate component include one or more selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, isophorone diisocyanate, methylene bis(4-cyclohexyl isocyanate), trimethylhexamethylene diisocyanate, hydrogenated tolylene diisocyanate, dicyclohexylmethane diisocyanate, carbodiimide-modified polyisocyanates of these, and isocyanurate-modified polyisocyanates of these.

[0020] Examples of the polyol component include one or more selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, co(polyethylene oxide-propylene oxide)diol, tetramethylene glycol, polytetramethylene glycol, bisphenol A, ethoxylated bisphenol A, caprolactam-modified polyol, carbonate polyol, polyester polyol, 1,6-hexanediol, trimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, and the like.

[0021] Examples of the (meth)acrylate compound having a hydroxyl group include one or more compounds selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, tris(hydroxyethyl)isocyanuric acid di(meth)acrylate, and pentaerythritol tri(meth)acrylate.

[0022] The polyurethane (meth)acrylate oligomer having 6 or more functionalities and a weight average molecular weight of 1,500 to 5,000 can be obtained by reacting an alicyclic polyisocyanate compound with a polyol to obtain a polyurethane oligomer having 6 or more isocyanate groups in the molecule, and then reacting a (meth)acrylate compound having a hydroxyl group. The number of (meth)acryloyl groups contained in one molecule of the polyurethane (meth)acrylate oligomer having 6 or more functionalities and a weight average molecular weight of 1,500 to 5,000 is not particularly limited as long as it is 6 or more, but from the viewpoint of the curability of the curable artificial nail composition and the hardness of the cured coating film, it is 6 or more, for example 10 or less, preferably 8 or less. In the present invention, the number of (meth)acryloyl groups can be confirmed by analysis using infrared absorption spectroscopy (IR), nuclear magnetic resonance (NMR), gas chromatography mass spectrometry (GC / MS), or the like.

[0023] ((Meth)acrylate oligomers other than polyurethane (meth)acrylate oligomers with 6 or more functional groups and a weight-average molecular weight of 1,500 to 5,000) The (meth)acrylate oligomer other than the hexa- or higher functional polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 to 5,000 is not particularly limited, but examples thereof include the following: (i) (meth)acrylate oligomers having in their main skeleton (main chain) one or more bonds selected from the group consisting of urethane bonds, bonds resulting from a ring-opening reaction of an epoxy group, ester bonds, ether bonds, urea bonds, carbonate bonds, and amide bonds; (ii) (meth)acrylate oligomers having in their main skeleton (main chain) 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; and the like.

[0024] In the (meth)acrylate oligomer other than the hexa- or higher-functional polyurethane (meth)acrylate oligomer having a weight-average molecular weight of 1,500 to 5,000, the number of (meth)acryloyl groups contained in one molecule is not particularly limited. From the viewpoint of the curability of the curable artificial nail composition, the hardness of the cured coating film, etc., the number is 1 or more, preferably 2 or more, and can be, for example, 10 or less, preferably 8 or less. The weight average molecular weight of the (meth)acrylate oligomer other than the 6- or more functional polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 to 5,000 is not particularly limited. For example, it is 1,000 or more, preferably 2,000 or more, more preferably 3,000 or more, and for example, it is 100,000 or less, preferably 50,000 or less, more preferably 35,000 or less. By setting the weight average molecular weight in this range, it is possible to improve the durability of the cured coating film while maintaining a low viscosity.

[0025] Among these, the use of 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 generated by a ring-opening reaction of an epoxy group, ester (meth)acrylate oligomers ((meth)acrylate oligomers having an ester bond in the main skeleton), and ether (meth)acrylate oligomers ((meth)acrylate oligomers having an ether bond in the main skeleton) is advantageous in terms of adhesion, etc. In the present invention, urethane (meth)acrylate oligomers are particularly preferably used. The (meth)acrylate oligomer may be either a commercially available product or a synthetic product. In the present invention, it is preferable that the composition contains one or more urethane (meth)acrylate oligomers from the viewpoint of adhesion and durability of the curable artificial nail composition and / or the cured coating film thereof.

[0026] The urethane (meth)acrylate oligomer can be synthesized, for example, by reacting a polyol with a polyisocyanate to form an isocyanate group- or hydroxyl group-containing urethane prepolymer, and then 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 the synthesis method is not limited to this method.

[0027] When a urethane (meth)acrylate oligomer is used in a curable artificial nail composition, a cured coating film having excellent elasticity, adhesion, and strength can be obtained. The one or more urethane (meth)acrylate oligomers usable in the present invention can be selected from those having one or more skeletons selected from the group consisting of polyether skeleton, polycarbonate skeleton, polyester skeleton, acrylic skeleton, and polyolefin skeleton. Among them, one or more polyether-based urethane (meth)acrylate oligomers having a polyether skeleton and / or polycarbonate-based urethane (meth)acrylate oligomers having a polycarbonate skeleton are preferred.

[0028] For example, a polyether-based urethane (meth)acrylate oligomer having one or more polyether skeletons can be obtained by adding a (meth)acrylic compound having a hydroxyl group, such as hydroxyethyl (meth)acrylate, to an isocyanate group-containing polyether urethane prepolymer obtained by reacting a polyoxyalkylene polyol, such as polyoxypropylene polyol, with a polyisocyanate, such as isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, or an isocyanurate or biuret product thereof, and subjecting 10% or more of the total number of isocyanate groups in the urethane prepolymer to an addition reaction with the (meth)acrylic compound having a hydroxyl group.

[0029] For example, a polycarbonate-based urethane (meth)acrylate oligomer having one or more polycarbonate skeletons can be obtained, like a polyether-based urethane (meth)acrylate oligomer, by adding a (meth)acrylic compound having a hydroxyl group, such as hydroxyethyl (meth)acrylate, to an isocyanate group-containing polycarbonate urethane prepolymer obtained by reacting a polycarbonate polyol with a polyisocyanate, and then subjecting 10% or more of the total number of isocyanate groups in the urethane prepolymer to an addition reaction with the (meth)acrylic compound having a hydroxyl group.

[0030] As the urethane (meth)acrylate oligomer, a commercially available product can be used. 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 Industries Co., Ltd.), SUA TH1, SUA 2, SUA-16N (manufactured by KSM Corporation), UV-3310B (manufactured by Mitsubishi Chemical Corporation), Art Resin UN-6303, UN-6304, UN-6305, UN-9000PEP, UN-9200A, UN-353, UN-333, UN-352 (manufactured by Negami Chemical Industries Co., Ltd.), AU-2040 (manufactured by Tokushiki Co., Ltd.), and KUA-PC2I (manufactured by KSM Corporation).

[0031] An epoxy (meth)acrylate oligomer having a molecular chain generated 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 reactive 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-Cytec), EPOXY ESTER 3000A, 3000MK, 3002A(N), 3002M(N), 40EM (manufactured by Kyoeisha Chemical Co., Ltd.).

[0032] An ester (meth)acrylate oligomer having an ester bond can be synthesized, for example, by adding a compound having a hydroxyl group and a (meth)acryloyl group in the molecule and / or (meth)acrylic acid or an acrylic compound having a carboxyl group to a carboxyl group and / or a hydroxyl group of an ester oligomer obtained by reacting a polyol with a polyvalent carboxylic acid, but is not limited to this method. Examples of commercially available products include, but are not limited to, one or more types selected from the group consisting of Aronix (registered trademark) M-6100, M-6200, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, and M-9050 (manufactured by Toagosei Co., Ltd.), and UV-3500BA, UV3520TL, UV-3200B, and UV-3000B (manufactured by Mitsubishi Chemical Corporation).

[0033] An ether (meth)acrylate oligomer having an ether bond can be synthesized, for example, by adding one or more members selected from the group consisting of a compound having a hydroxyl group and a (meth)acryloyl group in the molecule, (meth)acrylic acid, and a compound having a carboxyl group and a (meth)acryloyl group in the molecule to a hydroxyl group of an aliphatic polyether polyol or a hydroxyl group of an aromatic polyether polyol made from a raw material such as bisphenol, 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 UV-6640B, UV-6100B, UV-3700B (manufactured by Mitsubishi Chemical Corporation), Light Acrylate (registered trademark) 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.), and EBECRYL (registered trademark) 3700 (manufactured by Daicel-Cytec Co., Ltd.).

[0034] <(Meth)acrylate Monomer> The (meth)acrylate monomer is not particularly limited as long as it is a compound other than the (meth)acrylate oligomer and has one or more (meth)acryloyl groups in the molecule. The number of (meth)acryloyl groups contained in one molecule is not particularly limited, but is one or more, for example, 10 or less, preferably 8 or less, more preferably 6 or less, from the viewpoint of the curability of the curable artificial nail composition and the hardness of the cured coating film. In the present invention, the (meth)acrylate monomer may be one or more selected from (meth)acrylate monomers having one (meth)acryloyl group. Also, a mixture of one or more selected from (meth)acrylate monomers having one (meth)acryloyl group and one or more selected from (meth)acrylate monomers having two or more (meth)acryloyl groups may be used.

[0035] Examples of the (meth)acrylate monomer 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, phenyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, and adamantyl (meth)acrylate. Esterification products of monohydric alcohols such as acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and dicyclopentanyl (meth)acrylate with (meth)acrylic acid; acrylamide, hydroxyethyl acrylamide, dimethyl acrylamide, diethyl acrylamide, 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, (meth)acryloyl group-containing amide compounds such as N-di-tert-octyl(meth)acrylamide, N,N-didodecyl(meth)acrylamide, N,N-dioctadecyl(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, hydroxybutyl(meth)acrylate, and pentaerythritol mono(meth)acrylate;Nitrogen-containing alkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and Nt-butylaminoethyl (meth)acrylate; phosphate ester (meth)acrylates such as (meth)acryloyloxyethyl phosphate, (meth)acryloyloxypropyl phosphate, caprolactone-modified (meth)acryloyloxyethyl phosphate, (meth)acrylic acid ethyl hexanoate phosphate, and (meth)acrylic acid pentyl propanoate phosphate; glycidyl (meth)acrylate, 4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, and (2-isobutyl-2-methyl-1,3-dioxolane-4-yl) Methyl (meth)acrylate, (2-methyl-2-methyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (1,4-dioxaspiro[4,5]decan-2-yl)methyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, pentamethylpiperidyl (meth)acrylate, N-(meth)acryloyloxysuccinimide, N-(meth)acryloyloxyphthalimide and other heterocyclic ring-containing (meth)acrylates can be mentioned as one or more selected from the group consisting of such acrylates.;

[0036] Among these (meth)acrylate monomers having one (meth)acryloyl group, straight-chain or branched alkyl group-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, and neopentyl (meth)acrylate; alicyclic mono(meth)acrylate monomers such as isobornyl (meth)acrylate, adamantyl (meth)acrylate, and cyclohexyl (meth)acrylate; hydroxyethyl acrylamide, dimethyl acrylamide, diethyl acrylamide, N-methyl (meth)acrylamide, and N-hydroxyethyl At least one selected from the group consisting of (meth)acrylamide, N-ethyl (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, and other (meth)acryloyl group-containing amide compounds; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and other hydroxyl group-containing (meth)acrylates; (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, and other heterocyclic ring-containing (meth)acrylates is preferred.

[0037] Examples of the (meth)acrylate monomer 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 ... ) acrylate, 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, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate (isopyridene dif di(meth)acrylates such as phosphate ester-based di(meth)acrylates, such as diphenyl bis(oxyhydroxypropyl methacrylate), isocyanuric acid di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, di(meth)acryloyloxyethyl phosphate, di(meth)acryloyloxypropyl phosphate, caprolactone-modified di(meth)acryloyloxyethyl phosphate, di(meth)acrylic acid ethyl hexanoate phosphate, and di(meth)acrylic acid pentyl propanoate phosphate; ) acrylate monomers; tri(meth)acrylate monomers such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and ε-caprolactone-modified tris(acryloxyethyl)isocyanurate; tetra(meth)acrylate monomers such as pentaerythritol tetra(meth)acrylate and dipentaerythritol tetra(meth)acrylate;Examples of the monomer include at least one selected from the group consisting of polypentaerythritol poly(meth)acrylates such as dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, and tetrapentaerythritol hexa(meth)acrylate, and (meth)acrylate monomers having four or more (meth)acrylate groups such as isocyanuric acid tri(meth)acrylate, triazine tri(meth)acrylate, ethoxylated isocyanuric acid triacrylate, and ethoxylated pentaerythritol tetraacrylate.

[0038] Of these (meth)acrylate monomers having two or more (meth)acryloyl groups, it is preferable to use one or more 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, and the like.

[0039] <(a) Composition and Content of (Meth)acrylate Compound> In the curable artificial nail composition of the present invention, the content of the (a) (meth)acrylate compound is not particularly limited, and is, for example, 20.0 mass% or more, preferably 40.0 mass% or more, more preferably 50.0 mass% or more, and even more preferably 60.0 mass% or more, relative to 100 mass% of the total amount of the curable artificial nail composition, and is, for example, 88.8 mass% or less, preferably 80.0 mass% or less, more preferably 75.0 mass% or less, and even more preferably 70.0 mass% or less.

[0040] In the curable artificial nail composition of the present invention, the content of the hexafunctional or higher polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 to 5,000 in the (a) (meth)acrylate compound is not particularly limited. It is, for example, 10.0% by mass or more, preferably 15.0% by mass or more, more preferably 20.0% by mass or more, and for example, 60.0% by mass or less, preferably 50.0% by mass or less, more preferably 40.0% by mass or less, and even more preferably 30.0% by mass or less, relative to 100% by mass of the total amount of the (a) (meth)acrylate compound.

[0041] In the present invention, it is preferable to use a mixture of a (meth)acrylate oligomer and a (meth)acrylate monomer as the (a) (meth)acrylate compound. In the curable artificial nail composition of the present invention, the content of the (meth)acrylate oligomer in the (meth)acrylate compound (a) is not particularly limited, and is, for example, 35.0% by mass or more, preferably 40.0% by mass or more, and for example, 90.0% by mass or less, preferably 80.0% by mass or less, based on 100% by mass of the total amount of the (meth)acrylate compound (a). If the content of the (meth)acrylate oligomer in the (a) (meth)acrylate compound is less than 35.0% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too low. If the content of the (meth)acrylate oligomer exceeds 90% by mass, the curability of the curable artificial nail composition may decrease and the viscosity may become too high.

[0042] [(b) Multifunctional thiol compound] The (b) polyfunctional thiol compound, which is a component of the curable artificial nail composition of the present invention, is not particularly limited as long as it is a compound having two or more thiol groups in the molecule. The (b) polyfunctional thiol compound is blended as a chain transfer agent, a curability regulator, a crosslinking agent, and a viscosity regulator of the curable artificial nail composition. By blending the polyfunctional thiol compound in the curable artificial nail composition, it is possible to suppress the remaining of uncured components on the surface of the cured coating film. Examples of polyfunctional thiol compounds include those obtained by reacting a hydroxyl group of a polyol compound such as trimethylolpropane, pentaerythritol, dipentaerythritol, or ethylene glycol with a compound having a thiol group or a group that reacts to become a thiol group. For example, trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tristhioglycolate, trimethylolpropane tris(3-mercaptobutyrate), pentaerythritol tetrakis thioglycolate, pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptobutyrate), 1,3,5-tris[2-(3-mercaptobutyryloxy)ethyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, tris[(3-mercaptopropionate)], pionyloxy)-ethyl]-isocyanurate, 1,4-bis(3-mercaptobutyryloxy)butane, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,2-cyclohexanedithiol, decanedithiol, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, ethylene glycol bisthioglycolate (EGTG), 1,4-butanediol bisthiopropionate (BDTG), trimercaptopropionic acid tris(2-hydroxyethyl)isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-triazine, Examples of the thiol compounds include polyfunctional thiol group-containing monomers such as 2-(N,N-dibutylamino)-4,6-dimercapto-s-triazine. Among these, trifunctional or tetrafunctional thiol compounds are preferred, and one or more selected from the group consisting of trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tristhioglycolate, trimethylolpropane tris(3-mercaptobutyrate), pentaerythritol tetrakis thioglycolate, pentaerythritol tetrakis(3-mercaptobutyrate), and pentaerythritol tetrakis(3-mercaptopropionate) are preferred.

[0043] [(c) α-Hydroxyalkylphenone-based polymerization initiator] The (c) α-hydroxyalkylphenone-based polymerization initiator, 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 imparted thereto by irradiation with light (e.g., ultraviolet light) or heat, and can initiate polymerization of the (a) (meth)acrylate compound. The (c) α-hydroxyalkylphenone-based photopolymerization initiator has a relatively high molar absorption coefficient and low yellowing.

[0044] Examples of the α-hydroxyalkylphenone type photopolymerization initiator include one or more selected from the group consisting of 1-hydroxy-cyclohexyl phenyl ketone (Omnirad 184), 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxymethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propan-1-one, 1-(4-(phenylthio)-2,2-(O-benzoyloxime))1-hydroxycyclohexyl phenyl ketone, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one.

[0045] [Relationship between (b) content of polyfunctional thiol compound and (c) content of α-hydroxyalkylphenone-based polymerization initiator] In the present invention, when the content of the (b) polyfunctional thiol compound relative to the total amount of the curable artificial nail composition is x mass %, and the content of the (c) α-hydroxyalkylphenone polymerization initiator relative to the total amount of the curable artificial nail composition is y mass %, the relationship between the content of the (b) polyfunctional thiol compound and the content of the (c) α-hydroxyalkylphenone polymerization initiator is the following relationship: (α) 20.0 ≧ x ≧ 3.5 (β) 15.0 ≧ y ≧ 0.5 (γ)x+6y≧18.5 (δ)3x+y≧21.5 Meet the following. This makes it possible to reduce the lower limit of the content of the (b) polyfunctional thiol compound to 3.5 mass%, and prevents uncured components from remaining on the surface of the cured coating film, resulting in a curable artificial nail composition that has excellent non-wipe properties and storage stability.

[0046] In the past, in order to make a curable artificial nail composition of the non-wipe type, it was necessary to use a polyfunctional thiol compound that causes a chain transfer reaction and a polyfunctional (meth)acrylate compound that enhances reactivity in combination. On the other hand, a non-wipe type curable artificial nail composition containing a polyfunctional thiol compound and a polyfunctional (meth)acrylate compound had a problem of poor storage stability. In order to obtain storage stability, it is required to reduce the amount of the polyfunctional thiol compound as much as possible, but in order to reliably express non-wipe properties, it is necessary to add a certain amount of polyfunctional thiol, thereby balancing non-wipe properties and storage stability.

[0047] The present invention is based on the finding that a curable artificial nail composition that is excellent in surface curability, non-wipe property, and storage stability can be obtained by adjusting the relationship between the content of (b) the polyfunctional thiol compound and the content of (c) the α-hydroxyalkylphenone polymerization initiator so that the relationship between them satisfies the above-mentioned (α) to (δ).

[0048] In the curable artificial nail composition of the present invention, the content x (mass%) of the (b) polyfunctional thiol compound relative to the total amount of the curable artificial nail composition is not particularly limited as long as it satisfies the relationship (α) to (δ). Among these, the lower limit value of x in (α) is 3.5 mass% or more, preferably 4.0 mass% or more, more preferably 4.5 mass% or more, and the upper limit value of x can be 20.0 mass% or less, preferably 15.0 mass% or less, more preferably 12.0 mass% or less. If the content x (mass%) of the (b) polyfunctional thiol compound relative to the total amount of the curable artificial nail composition exceeds 20.0 mass%, the storage stability of the curable artificial nail composition may decrease, and problems may occur in terms of the odor of the curable artificial nail composition. If it is less than 3.5 mass%, the curable artificial nail composition may not be sufficiently cured, and uncured components may remain on the surface of the cured coating film, making it impossible to obtain a non-wipe type curable artificial nail composition.

[0049] In the curable artificial nail composition of the present invention, the content of (c) α-hydroxyalkylphenone-based polymerization initiator y (mass%) relative to the total amount of the curable artificial nail composition is not particularly limited as long as the relationship of (α) to (δ) is satisfied. Among these, the lower limit of y in (β) is 0.5 mass% or more, preferably 1.0 mass% or more, more preferably 1.5 mass% or more, and the upper limit of y can be 15.0 mass% or less, preferably 12.0 mass% or less, more preferably 10.0 mass% or less. Even if the content y% of (c) α-hydroxyalkylphenone-based polymerization initiator relative to the total amount of the curable artificial nail composition exceeds 15.0 mass%, there is no difference in the obtained characteristics, etc., and there is a possibility that it is disadvantageous in terms of costs, etc., and if it is less than 0.5 mass%, the curable artificial nail composition is not sufficiently cured, and uncured components remain on the surface of the cured coating film, and it is possible that it is not possible to obtain a non-wipe type curable artificial nail composition.

[0050] [(d) Other ingredients] In addition to the above (a) to (c), various components can be blended into the curable artificial nail composition of the present invention as “(d) other components” within a range that does not adversely affect the storage stability, curability, color tone of the cured coating film, durability of the cured coating film, adhesion of the cured coating film, viscosity, handleability, coatability, etc. Examples of the (d) other components include one or more selected from the group consisting of various additives such as radical polymerizable compounds other than the (a) (meth)acrylate compounds, resins, polymerization initiators other than the (c) α-hydroxyalkylphenone-based polymerization initiators, polymerization inhibitors, colorants, polyol compounds, solvents, fragrances, anti-settling agents such as alumina, silicone-based and fluorine-based defoamers, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, polymerization accelerators such as tertiary amines, surface tension adjusters, flame retardants, antioxidants, ion adsorbents, stress reducers, preservatives, antibacterial agents, flexibility imparting agents, waxes, halogen traps, leveling agents, wetting improvers, and decorative materials.

[0051] <(a) Radically polymerizable compound other than (meth)acrylate compound> (a) The radical polymerizable compound other than the (meth)acrylate compound is not particularly limited as long as it is a radical polymerizable compound other than the (meth)acryloyl group-containing polymerizable compound. For example, one or more compounds selected from the group consisting of vinyl group-containing compounds, allyl group-containing compounds, etc. are included. Specifically, one or more compounds 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. are included.

[0052] <Resin> The resin is not particularly limited as long as it is neither polymerizable nor a polyol compound, and examples thereof include at least one 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, and block resins.

[0053] <(c) Polymerization initiators other than α-hydroxyalkylphenone-based polymerization initiators> The polymerization initiator other than the (c) α-hydroxyalkylphenone-based polymerization initiator is not particularly limited as long as it is an α-hydroxyalkylphenone-based polymerization initiator that generates radicals when given energy by irradiation with light (e.g., ultraviolet light) or heat, and can initiate polymerization of the (a) (meth)acrylate compound. For example, one or more polymerization initiators selected from the group consisting of acylphosphine oxide-based, α-hydroxyalkylphenone-based, benzoin ether-based, benzil ketal-based, acid ester-based, α-aminoalkylphenone-based, benzophenone-based, thioxanthone-based, titanocene-based, quinone-based, peroxide-based, azo-based, persulfate-based, etc. may be mentioned. (c) When a photopolymerization initiator is used as a polymerization initiator other than an α-hydroxyalkylphenone-based polymerization initiator, good curability can be imparted to the curable artificial nail composition even when the curable artificial nail composition is irradiated with light using various light sources including a UV-LED light source.

[0054] For example, an acylphosphine oxide-based polymerization initiator generates radicals when irradiated with ultraviolet light having a wavelength of about 365 nm to about 405 nm emitted from a commonly used UV-LED light source. Therefore, even when the composition is cured by irradiating light using various light sources including a UV-LED light source, the initiator can impart good curability to the curable composition, and further, when the composition is cured by irradiating light using a UV-LED light source, the initiator can prevent yellowing of the cured coating film, and is therefore preferably used. Examples of the acylphosphine oxide polymerization initiator include one or more selected from the group consisting of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, etc. In particular, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (OMNIRAD TPO) can be preferably used in the present invention since it also functions as a skin conditioning agent.

[0055] Examples of polymerization initiators other than the acylphosphine oxide polymerization initiator include 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-oxy]-2-hydroxypropyl-N,N,N-trimethylammonium chloride, fluorothioxanthone, 2-benzyl-2-dimethylamino-1-(4-methylamino)-2-propanediol, 2-methyl ... 2-Methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-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-morpholinopropan-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 phenylglyoxylate, butyl anthraquinone, ethyl anthraquinone, phenanthrenequinone, camphorquinone, benzophenone, 4-phenylbenzophenone, benzoylbenzoic acid, hydroxybenzophenone, 4,4'-bis(diethylamino)benzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin Zoin 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-cyclohexanecarbonitrile), 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, disuccinic acid peroxide, dibenzoyl peroxide, parachlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, t-butyl peroxybenzoate, t-hexyl peroxide parethate, 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, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexa Examples of the peroxydicarbonate include at least one selected from the group consisting of peroxydicarbonate, 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, and ammonium persulfate.

[0056] In the curable artificial nail composition of the present invention, it is preferable to use a polymerization initiator that can efficiently generate radicals and initiate polymerization in the ultraviolet wavelength region (for example, wavelengths around 405 nm and around 365 nm) irradiated during curing, and it is more preferable to use a mixture of an α-hydroxyalkylphenone polymerization initiator and another polymerization initiator, in particular, a polymerization initiator mixture containing an α-hydroxyalkylphenone polymerization initiator and an acylphosphine oxide polymerization initiator. In addition to the acylphosphine oxide polymerization initiator, a polymerization initiator containing an α-hydroxyalkylphenone polymerization initiator may be used, and a polymerization initiator composition containing an acylphosphine oxide polymerization initiator and a peroxide polymerization initiator may also be used.

[0057] In the curable artificial nail composition of the present invention, when a polymerization initiator containing an acylphosphine oxide-based polymerization initiator and an α-hydroxyalkylphenone-based polymerization initiator is used as the polymerization initiator, the content of the acylphosphine oxide-based 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 can be, for example, 15.0% by mass or less, preferably 12.0% by mass or less, more preferably 10.0% by mass or less, based on 100% by mass of the total amount of the curable artificial nail composition. If the content of the acylphosphine oxide-based polymerization initiator exceeds 15.0% by mass, the cured coating film of the curable artificial nail composition may become brittle or may turn yellow (yellowing). If the content of the acylphosphine oxide-based polymerization initiator is less than 0.05% by mass, the curing heat of the curable artificial nail composition may be high, and the temperature rise during curing may be large.

[0058] <Polymerization inhibitor> The polymerization inhibitor is not particularly limited as long as it is a compound capable of suppressing the polymerization of the (a) (meth)acrylate compound. For example, one or more selected from the group consisting of tocopherol-based compounds, quinone-based compounds, phenol-based compounds, catechol-based compounds, oxydiphenylamine-based compounds, nitroso-based compounds, nitrone-based compounds, nitrile-based compounds, hydrazyl-based compounds, and phenothiazine-based compounds can be mentioned. Among these, it is preferable to use tocopherol-based compounds and / or quinone-based compounds.

[0059] Examples of tocopherol compounds include tocol, α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, η-tocopherol, α-tocotrienol, β-tocotrienol, γ-tocotrienol, δ-tocotrienol, α-tocopherol acetate, β-tocopherol acetate, γ-tocopherol acetate, δ-tocopherol acetate, α-tocopherol succinate, β-tocopherol succinate, γ-tocopherol succinate, and δ-tocopherol succinate. α-tocopherol glycine ester, β-tocopherol glycine ester, γ-tocopherol glycine ester, δ-tocopherol glycine ester, α-tocotrienol acetate, β-tocotrienol acetate, γ-tocotrienol acetate, δ-tocotrienol acetate, α-tocotrienol succinate, β-tocotrienol succinate, γ-tocotrienol succinate, δ-tocotrienol succinate, and the like. Preferably, there is one or more selected from the group consisting of tocol, α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, η-tocopherol, α-tocotrienol, β-tocotrienol, γ-tocotrienol, δ-tocotrienol, α-tocopherol acetate, β-tocopherol acetate, γ-tocopherol acetate, δ-tocopherol acetate, and the like.

[0060] Examples of quinone compounds include one or more compounds selected from the group consisting of hydroquinone, hydroquinone monomethyl ether, 1-o-2,3,5-trimethylolhydroquinone, 2-tert-butylhydroquinone, methylhydroquinone, dimethylhydroquinone, di-t-butylhydroquinone, benzoquinone, p-benzoquinone, 2,6-dichloro-p-benzoquinone, and 2,5-dichloro-p-benzoquinone.

[0061] An example of the phenolic compound is 3,5-t-dibutyl-6-hydroxytoluene. Examples of the catechol compounds include catechol, 4-t-butylcatechol, and the like. Examples of the oxydiphenylamine compounds include 2-oxydiphenylamine, its hydroxyl position isomers, phenyl group substitution products, and amino group alkyl substitution products. Examples of nitroso compounds include compounds having a nitroso group on the α-carbon of a carbonyl compound (e.g., methyl-α-nitrosoisopropyl ketone), N-nitroso-N-phenylhydroxylamine compounds (e.g., N-nitroso-N-phenylhydroxylamine ammonium salt, N-nitroso-N-phenylhydroxylamine aluminum salt), and the like. An example of the nitrone compound is phenyl-t-butyl nitrone. Examples of nitrile compounds include compounds in which a nitrile group is conjugated (such as furfurylidenemalononitrile). A preferred example of the hydrazyl compound is 1,1-diphenyl-2-picrylhydrazyl. Examples of phenothiazine compounds include phenothiazine or compounds having one or more substituents on the aromatic ring moiety.

[0062] In the curable artificial nail composition of the present invention, the content of the polymerization inhibitor is not particularly limited. For example, it can be more than 0% by mass and 1.0% by mass or less based on the total amount of the curable artificial nail composition. It is preferably 0.01% by mass or more, more preferably 0.03% by mass or more. If the content of the polymerization inhibitor exceeds 1.0% by mass, there is a risk that uncured components remain on the surface of the curable artificial nail composition, and the composition may thicken over time, resulting in a decrease in applicability and handling, and if no polymerization inhibitor is contained, there is a risk that the storage stability may decrease.

[0063] <Coloring agent> The colorant may be one or more selected from the group consisting of pigments, luster materials, and dyes, and may be used in any amount to impart a desired color tone to the curable artificial nail composition. In particular, the colorant may be one or more selected from the group consisting of inorganic pigments, luster materials, organic pigments, and dyes used in nail coating materials, and does not significantly inhibit curing by irradiation with ultraviolet light (light irradiation) or the like. The curable artificial nail composition before curing can contain not only pigments but also resin particles and decorative materials that can be incorporated into known curable artificial nail compositions.

[0064] 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 106, Red 2, Red 201, Red 202, Red 203, Red 204, Red 205, Red 206, Red 207, Red 208, Red 213, Red 214, Red 215, Red 218, Red 219, Red 220, Red 221, Red 223, Red 225, Red 226, Red 227, Red 228, Red 230-(1), Red 23 Examples of the pigments include one or more selected from the group consisting of Red No. 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 oxide, iron oxide, chromium oxide, manganese violet, carbon black, metal powder, metal flakes, metal oxide flakes, glass flakes, and the like.

[0065] In the curable artificial nail composition of the present invention, it is preferable to incorporate a bluing agent in order to form a transparent cured coating film and suppress yellowing of the cured coating film. The bluing agent used in the present invention is preferably one containing a blue colorant and a reactive diluent. As the blue-based colorant, for example, a colorant containing one or more selected from the group consisting of 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, etc., is used, preferably a colorant containing one or more selected from the group consisting of 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, etc. is used. As the reactive diluent, one or more selected from the group consisting of (meth)acrylate monomers in the (a) (meth)acrylate compound can be used.

[0066] <Polyol compound> The polyol compound functions as a diluent and an adhesion improver for the curable artificial nail composition. Examples of the polyol compound include one or more selected from the group consisting of alkyl polyols, polyester polyols, polyether polyols, acrylic polyols, polybutadiene polyols, and phenolic polyols. Among them, alkyl polyols, polyester polyols, and polyether polyols are preferred. The alkyl polyol may be at least one 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.

[0067] The polyester polyol may be one or more selected from the group consisting of condensation polyester polyol, addition polymerization polyester polyol, polycarbonate polyol, etc. The condensation polyester polyol may be 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, diol dimer acid, 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 the molecular weight is preferably 100 to 100,000. The addition polymerization polyester polyol may be polycaprolactone, and the molecular weight is preferably 100 to 100,000. Polycarbonate polyols are synthesized by direct phosgenation of polyols, transesterification with diphenyl carbonate, or the like, and preferably have a molecular weight of 100 or more and 100,000 or less. An example of the polyether polyol is a polyether polyol obtained by ring-opening polymerization of an alkylene oxide.

[0068] <Solvent> The solvent is not particularly limited as long as it can adjust the viscosity at the time of application by dilution. For example, one or more selected from the group consisting of 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; acetates such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol.

[0069] [Viscosity of Curable Artificial Nail Composition] The curable artificial nail composition of the present invention can have a viscosity at 25° C. of, for example, 0.1 Pa·s or more and 60.0 Pa·s or less. The viscosity is preferably 0.5 Pa·s or more, more preferably 0.7 Pa·s or more, and is preferably 50.0 Pa·s or less, more preferably 40.0 Pa·s or less. By setting the viscosity within such a range, a curable artificial nail composition that is excellent in applicability with an applicator such as a brush or inkjet can be obtained.

[0070] [Uses of the curable artificial nail composition] The curable artificial nail composition of the present invention is a composition for coating the surface of the nail, like common manicures and pedicures. The curable artificial nail composition of the present invention can be particularly suitably used as a gel nail, and can be used to form any of the layers, for example, a base coat layer applied directly to the user's nail, a color coat layer applied on the base coat layer, and a top coat layer applied on the base coat layer, without chipping or peeling off the cured coating film for a long period of time (for example, at least two weeks after curing), and can suppress lifting from occurring on the lower layer or the user's nail. In particular, it can be used as a curable artificial nail composition for a non-wipe type top coat layer with excellent curability.

[0071] The curable artificial nail composition of the present invention can be suitably used, in particular, as a color top coat layer having a desired color tone, a clear top coat layer to which a desired color tone may be imparted, or a clear top coat layer containing glittering materials such as metal powder, metal flakes, metal oxide flakes, glass flakes, etc. After applying the curable artificial nail composition of the present invention and before curing, it is also possible to attach small decorations, powders, etc. to the coating film surface of the curable artificial nail composition to enhance the design.

[0072] [Coating nails with a curable artificial nail composition] The nails to be coated with the curable composition of the present invention may be either human fingernails or toenails, or may be the nails of animals such as dogs and cats, etc. Furthermore, they may be artificial nails such as nail tips (false nails). When the curable artificial nail composition of the present invention is applied to a nail or an (un)cured coating film on the nail to form a coating, the applied surface may or may not be sanded. The method for applying the curable artificial nail composition is not particularly limited, and for example, an application method using an applicator such as a brush or an inkjet may be used.

[0073] 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 this layer can be brought into contact (transferred) with the nail surface, and then cured by irradiating with ultraviolet light, with or without peeling off the sheet. By using a method in which an uncured coating layer is first formed on the sheet surface using a curable artificial nail composition and then this is transferred, it is possible to coat the nail surface with a uniform and accurate pattern without using an applicator such as a brush, and there is no need to wash the applicator after use.

[0074] The means for curing the curable artificial nail composition after application is not particularly limited as long as it is a means capable of imparting energy for causing the curing of the curable artificial nail composition. Examples include irradiation with energy rays such as light (ultraviolet rays (UV) etc.), electron beams, and heat. In particular, curing by irradiation with ultraviolet rays (UV) can be preferably used since it can be carried out relatively quickly and easily. When curing by irradiation with light such as ultraviolet rays, 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 rays, the irradiation energy (accumulated light amount) by light irradiation is, for example, 5 mJ / cm. 2 More than 10 mJ / cm, preferably 10 mJ / cm 2 or more, for example 1000 mJ / cm 2 Less than or equal to 800 mJ / cm 2 If the irradiation energy is within this range, nail art having sufficient adhesion and abrasion resistance can be obtained. As a light source for irradiating light, for example, a known ultraviolet light source such as a multi-type UV lamp (UV+LED), a mercury lamp, a metal halide lamp, an ultraviolet light emitting diode (UV-LED), an ultraviolet laser diode (UV-LD), etc. Among them, from the viewpoints of small size, long life, high efficiency, and low cost, a multi-type lamp (UV+LED) (three-line main wavelength: about 365 nm, about 405 nm, and about 436 nm), an ultraviolet light emitting diode (UV-LED; wavelength about 385 nm to about 415 nm; peak wavelength about 405 nm), and an ultraviolet laser diode (UV-LD) are preferred. EXAMPLES

[0075] 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 "% by mass" and "parts" means "parts by mass."

[0076] [Examples 1 to 14, Comparative Examples 1 to 5] The components shown in Tables 1 and 2 were placed in a vessel in the amounts (parts by mass) shown in Tables 1 and 2, respectively, and heated to 50° C. while stirring with a dissolver. The mixture was defoamed for 10 minutes under a pressure of 0.1 MPa while stirring, and then allowed to stand at 50° C. for 2 hours and defoamed to obtain a curable artificial nail composition. All of these steps were performed in the dark.

[0077] <Ingredients> The components in Tables 1 and 2 are as follows: PU1: Difunctional polyether polyurethane (meth)acrylate PU2: 6-functional alicyclic polyurethane (meth)acrylate (weight average molecular weight 2,400) PU3: 4-functional alicyclic polyurethane (meth)acrylate (weight average molecular weight 1,800) PU4: Difunctional alicyclic polyurethane (meth)acrylate (weight average molecular weight 3,000) PETA: Pentaerythritol tetraacrylate HEMA: 2-hydroxyethyl methacrylate PEMP: Pentaerythritol tetrakis(3-mercaptopropionate) HCPK: 1-hydroxycyclohexyl phenyl ketone TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide a-TP: α-tocopherol Blu-Agt: Bluing agent (Purple 201 / HEMA = 0.1% by mass / 99.9% by mass)

[0078] <Surface hardening> The obtained curable artificial nail composition was applied onto a hard polyvinyl chloride plate to form a coating film with a thickness of 100 μm, and the composition was cured by irradiation with a 36 W multi-type (UV+LED) lamp (irradiation wavelength: about 385 nm to about 415 nm) for 30 seconds to obtain a test piece with a cured coating film. The surface of the obtained cured coating film immediately after curing was touched with the fingers, and the surface curability was evaluated based on the presence or absence of adhesion and tackiness on the surface according to the following criteria. A and B are acceptable, and C and D are unacceptable. The evaluation results of the surface curability are shown in Tables 1 and 2. A: No uncured components remain on the surface of the cured coating. The surface of the cured coating does not feel tacky when touched. B: No uncured components remain on the surface of the cured coating. The surface of the cured coating feels slightly tacky when touched. C: No uncured components remain on the surface of the cured coating. The surface of the cured coating feels tacky when touched, and the test piece sticks to the finger holding it down. D: Uncured components remain on the surface of the cured coating film. When the surface of the cured coating film is touched, the uncured components stick to the fingers and become sticky.

[0079] [Table 1]

[0080] [Table 2]

[0081] As shown in Tables 1 and 2, the curable artificial nail compositions of Examples 1 to 14 all had excellent surface curability, whereas the curable artificial nail compositions of Comparative Examples 1 to 5 all had poor surface curability. This shows that the curable artificial nail compositions of Examples 1 to 14 all had no uncured components remaining on the surface of the cured coating film when a cured coating film was formed on a nail, and are therefore useful as non-wipe type gel nails, and are particularly useful as non-wipe type top gel nails.

Claims

[Claim 1] (a) a (meth)acrylate compound, (b) a polyfunctional thiol compound, and (c) an α-hydroxyalkylphenone-based polymerization initiator, Contains The (a) (meth)acrylate compound includes at least one type of hexa- or higher-functional polyurethane (meth)acrylate oligomer having a weight average molecular weight of 1,500 or more and 5,000 or less, When the content of the polyfunctional thiol compound (b) relative to the total amount of the curable artificial nail composition is x mass %, and the content of the α-hydroxyalkylphenone-based polymerization initiator (c) relative to the total amount of the curable artificial nail composition is y mass %, the following relationship is satisfied: (α)20.0≧x≧3.5 (β)15.0≧y≧0.5 (γ)x+6y≧18.5 (δ)3x+y≧21.5 The present invention relates to a curable artificial nail composition.

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