Sclerosing artificial claw composition

Abstract

To provide a curable artificial nail composition having characteristics, such as adhesion (adhesive force to a nail) to a base material for a cured coating film, adhesion persistence, curability, and beauty of the cured coating film, and excellent in application workability with a low temperature rise during curing.SOLUTION: In a curable artificial nail composition, a temperature rise during curing is 23°C or lower, and a viscosity at 25°C is 0.1 Pa-s or higher and 60.0 Pa-s or lower.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. Also, 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 photocurable artificial nail composition called gel nail has attracted attention. Gel nail is a photocurable gel-like nail coating material (photocurable 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 it is said that a tough film that is difficult to peel off from the nail can be formed by a radical polymerization reaction to form a crosslinked polymer film.

[0004] So far, curable artificial nail compositions such as gel nails have been mainly studied from the viewpoints of adhesion of the cured coating film to the substrate (adhesive force to the nail), adhesion persistence, curability, aesthetic appearance of the cured coating film, etc. The conventional photocurable artificial nail compositions have not been studied in detail about the temperature rise during curing, which is caused by the heat of curing (heat of polymerization) generated when the photocurable compound undergoes photopolymerization to form a cured coating film. And there was a risk of giving the user a feeling of heat and discomfort due to the temperature rise during curing. Therefore, there is a need for a curable artificial nail composition that has characteristics such as adhesion of the cured coating film to the substrate (adhesive force to the nail), adhesion persistence, curability, aesthetic appearance of the cured coating film, etc., and further has a low temperature rise during curing.

[0005] Regarding the temperature rise during curing that occurs during the photopolymerization of gel nails, the following studies have been conducted so far. Patent Document 1 describes a base coat composition for auto nails containing a urethane acrylate oligomer, a monomer component containing at least hydroxyethyl acrylamide and 2-hydroxyethyl methacrylate, a photopolymerization initiator, and a polymer component. The heat during curing of this composition has been evaluated for sensitivity in three levels: large, medium, and small, but the specific temperature is unknown. Patent Document 2 describes a photocurable artificial nail composition containing a urethane (meth)acrylate oligomer, a polyfunctional thiol compound, a radically polymerizable compound, a photopolymerization initiator, and a chain transfer agent. Regarding the temperature rise during curing of this composition, it has been evaluated for sensitivity in three levels: "feel", "feel slightly", and "feel as heat pain", but the specific temperature is unknown. In these Patent Documents 1 and 2, only the sensitivity evaluation of the temperature rise during curing of the curable artificial nail composition has been carried out, and there is no description or suggestion regarding controlling the range of the temperature rise during curing to a specific range and controlling the temperature rise during curing from the composition aspect of the curable artificial nail composition.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved by the present invention is to obtain a curable artificial nail composition that has properties such as adhesion of the cured coating film to the substrate (adhesive force to the nail), adhesion sustainability, curability, and aesthetic appearance of the cured coating film, and further has a low temperature rise during curing and excellent coating workability.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by using a curable artificial nail composition having a specific composition, and has completed the present invention. Specifically, it is as follows. Item 1: A curable artificial nail composition having a temperature rise during curing of 23°C or less and a viscosity at 25°C of 0.1 Pa·s or more and 60.0 Pa·s or less. Item 2: The curable artificial nail composition according to Item 1, wherein the content of the acryloyl group-containing polymerizable compound is 0% by mass or more and 30% by mass or less based on 100% by mass of the total components of the curable artificial nail composition.

Effects of the Invention

[0009] The curable artificial nail composition of the present invention has properties such as adhesion of the cured coating film to the substrate (adhesive force to the nail), adhesion persistence, curability, and aesthetic appearance of the cured coating film, and further exhibits a remarkable effect of having a low temperature rise during curing and excellent coating workability.

Modes for Carrying Out the Invention

[0010] The curable artificial nail composition of the present invention will be described below. The curable artificial nail composition of the present invention cures by applying energy. For example, a photocurable artificial nail composition that cures by irradiation with light such as ultraviolet light (UV) can be mentioned, but it is not particularly limited. The curable artificial nail composition of the present invention is a curable artificial nail composition having a temperature rise during curing of 23°C or less and a viscosity at 25°C of 0.1 Pa·s or more and 60.0 Pa·s or less. Further, in the curable artificial nail composition of the present invention, the content of the acryloyl group-containing polymerizable compound can be 0% by mass or more and 30% by mass or less based on 100% by mass of the total components of the curable artificial nail composition. The inventor has found that by setting the temperature rise during curing of the curable artificial nail composition to 23°C or lower, when the curable artificial nail composition is cured by light (ultraviolet light) irradiation or the like after application, it does not give the user a sense of heat or discomfort. Further, when the temperature rise during curing is 23°C or lower, and the viscosity of the curable artificial nail composition at 25°C is 0.1 Pa·s or more and 60.0 Pa·s or less, it has been found that a curable artificial nail composition excellent in application workability can be obtained. Furthermore, by setting the content of the acryloyl group-containing polymerizable compound to 0 mass% or more and 30 mass% or less based on 100 mass% of the total of all components of the curable artificial nail composition, it has been found that the temperature rise during curing can be lowered and the viscosity at 25°C can be within a suitable range. Although the mechanism by which the curable artificial nail composition of the present invention can reduce the temperature rise during curing is unknown, the inventor speculates as follows. The methacryloyl group has a bulkier molecular structure than the acryloyl group and is prone to steric hindrance, resulting in lower reactivity. Along with this, the molecular mobility decreases, the glass transition temperature (Tg) increases, and the fluidity of the continuous layer decreases even at the initial stage of the reaction. When the fluidity of the continuous layer decreases, the degree of freedom of the radicals contributing to the reaction decreases, and as a result, the reactivity decreases, so that the temperature rise during curing can be reduced. It should be noted that the present invention is not limited to this speculation.

[0011] [Temperature rise during curing] The temperature rise during curing of the curable artificial nail composition of the present invention is 23°C or lower. The temperature rise during curing of the curable artificial nail composition can be determined by the method described in the examples below. The temperature rise during curing of the curable artificial nail composition is 23°C or lower, preferably 20°C or lower, and more preferably 15°C or lower. If the temperature rise during curing exceeds 23°C, the user will strongly feel a sense of heat on the nail and may feel discomfort. The lower limit of the temperature rise during curing is not particularly limited, but is, for example, 0°C or higher, preferably 5°C or higher. If it is less than 0°C, the user will strongly feel a sense of cold on the nail and may feel discomfort.

[0012] The curable artificial nail composition of the present invention is not particularly limited as long as it has curability with a temperature rise during curing of 23°C or less. As a means for curing, there is no particular limitation as long as it can impart energy that causes an effect on the curable composition. For example, irradiation with energy rays such as light and ultraviolet rays can be mentioned. The present inventors have found that compounds with high reactivity, particularly compounds with high photoreactivity, tend to generate heat when cured (polymerized) by light irradiation or the like, and the temperature rise during curing becomes high. Therefore, do not use a relatively highly reactive compound such as an acryloyl group-containing polymerizable compound (acrylate compound), or reduce the content of the acryloyl group-containing polymerizable compound with respect to 100% by mass of the total components of the curable artificial nail composition, or reduce the content of the acryloyl group-containing polymerizable compound with respect to 100% by mass of the total of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound in the curable artificial nail composition, whereby it is possible to control the temperature rise during curing of the curable artificial nail composition.

[0013] The curable artificial nail composition of the present invention can be constituted by, for example, a curable artificial nail composition containing an acryloyl group-containing polymerizable compound, a methacryloyl group-containing polymerizable compound, and a polymerization initiator, and optionally containing other components. The acryloyl group-containing polymerizable compound, the methacryloyl group-containing polymerizable compound, the polymerization initiator, and other components are not particularly limited as long as they can be used in the curable artificial nail composition. By reducing the content of the acryloyl group-containing polymerizable compound to 30% by mass or less, preferably 29% by mass or less, with respect to 100% by mass of the total components of the curable artificial nail composition, the temperature rise during curing can be controlled to 23°C or less. In addition, with respect to the acryloyl group-containing polymerizable compound, its content is small, for example, 20% by mass or less, preferably 15% by mass or less, more preferably 12% by mass or less, based on 100% by mass in total of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound in the curable artificial nail composition. By increasing the amount of the methacryloyl group-containing polymerizable compound having relatively low reactivity, the temperature rise during curing can be controlled to 23°C or lower. Furthermore, by using an acryloyl group-containing polymerizable compound and / or a methacryloyl group-containing polymerizable compound having a relatively high degree of polymerization (large weight average molecular weight), the temperature rise during curing can be controlled to 23°C or lower.

[0014] Examples of the acryloyl group-containing polymerizable compound include one or more selected from the group consisting of acrylate oligomers and acrylate monomers. Examples of the methacryloyl group-containing polymerizable compound include one or more selected from the group consisting of methacrylate oligomers and methacrylate monomers. Hereinafter, acrylate oligomers, acrylate monomers, methacrylate oligomers, and methacrylate monomers will be described in detail. In this specification, acrylate oligomers and methacrylate oligomers may be referred to as “(meth)acrylate oligomers”, and acrylate monomers and methacrylate monomers may be referred to as “(meth)acrylate monomers”.

[0015] ((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 viewpoints of the curability of the curable artificial nail composition, the hardness of the cured coating film, etc., it is 1 to 10, preferably 2 to 8. The number of (meth)acryloyl groups can be confirmed by analysis using infrared absorption spectroscopy (IR), nuclear magnetic resonance method (NMR), gas chromatography-mass spectrometry (GC / MS), etc.

[0016] (Meta)acrylate oligomers have a weight average molecular weight that is not particularly limited. For example, it is 1,000 to 100,000, preferably 2,000 to 30,000, and more preferably 3,000 to 20,000. By setting the range of the weight average molecular weight within such a range, the durability of the cured coating film can be improved while maintaining low viscosity.

[0017] (Meta)acrylate oligomers are not particularly limited. For example, (Meta)acrylate oligomers having one or more selected from the group consisting of urethane bonds, bonds formed by ring-opening reactions of epoxy groups, ester bonds, ether bonds, urea bonds, carbonate bonds, and amide bonds in the main skeleton (main chain), (Meta)acrylate oligomers having a molecular chain formed by polymerization of one or more monomers selected from the group consisting of styrene-based, (meta)acrylic-based, olefin-based, and diene-based monomers in the main skeleton (main chain), etc. One or more selected from the group consisting of can be mentioned. Among these, when using one or more selected from the group consisting of urethane (meta)acrylate oligomers (meta)acrylate oligomers having a urethane bond in the main skeleton), epoxy (meta)acrylate oligomers having a molecular chain formed by ring-opening reaction of epoxy groups, ester (meta)acrylate oligomers (meta)acrylate oligomers having an ester bond in the main skeleton), ether (meta)acrylate oligomers (meta)acrylate oligomers having an ether bond in the main skeleton), etc., it is advantageous in terms of adhesion and the like. (Meta)acrylate oligomers may be either commercially available products or synthetic products. Also, in the present invention, from the viewpoints of nail adhesion and durability of the curable resin composition and / or its cured coating film, it is preferable to contain one or more urethane (meta)acrylate oligomers. (Meta)acrylate oligomers can also be used by mixing with oligomers other than (meta)acrylate oligomers.

[0018] The urethane (meth)acrylate oligomer can be synthesized, for example, by forming an isocyanate group-containing urethane prepolymer through the reaction of a polyol and a polyisocyanate, and then reacting the isocyanate group-containing urethane prepolymer with a compound having an active hydrogen-containing group and a (meth)acryloyl group in the molecule (such as hydroxyalkyl (meth)acrylate, (meth)acrylic acid, etc.), but is not limited to this method. Commercially available products include 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 (manufactured by KSM), UV-3310B (manufactured by Mitsubishi Chemical Corporation), UN-9000PEP, UN-9200A, AU-2040 (manufactured by Tokushiki Co., Ltd.), KUA-PC2I (manufactured by KSM), etc., but are not limited thereto.

[0019] When the 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 non-aromatic polyether skeleton, an aromatic polyether skeleton, a non-aromatic polycarbonate skeleton, an aromatic polycarbonate skeleton, a non-aromatic polyester skeleton, and an aromatic polyester skeleton. Among them, those having one or more of a non-aromatic polyether skeleton and a (non)-aromatic polycarbonate skeleton are preferred.

[0020] For example, a urethane (meth)acrylate oligomer having one or more non-aromatic polyether skeletons can be obtained by adding a (meth)acrylic compound having a hydroxyl group to an isocyanate group-containing polyether urethane prepolymer and subjecting the isocyanate groups in the urethane prepolymer that account for 10% or more of the total number of isocyanate groups to an addition reaction with the (meth)acrylic compound having a hydroxyl group. Here, the isocyanate group-containing polyether urethane prepolymer is obtained by reacting a polyol compound having an alkylene group with 3 or more carbon atoms with a polyisocyanate, and for example, has a weight average molecular weight of 400 to 30,000. As the polyol compound, polypropylene polyol is preferred. As the polyisocyanate, non-aromatic polyisocyanates, for example, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isocyanurate compounds thereof, biuret compounds, etc., one or more selected from the group consisting of these can be mentioned.

[0021] The epoxy (meth)acrylate oligomer having a molecular chain generated by the 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. Commercially available products include, for example, one or more selected from the group consisting of EBECRYL 1259, 605, 1606 (manufactured by Daicel Cytec Co., Ltd.), EPOXY ESTER 3000A, 3000MK, 3002A(N), 3002M(N), 40EM (manufactured by Kyoeisha Chemical Co., Ltd.), etc., but are not limited thereto.

[0022] The 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 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 polyvalent carboxylic acid, but is not limited to this method. Commercially available products include, for example, but are not limited to, one or more 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, M-9050 (manufactured by Toagosei Co., Ltd.), UV-3500BA, UV3520TL, UV-3200B, UV-3000B (manufactured by Mitsubishi Chemical Corporation), etc.

[0023] The ether (meth)acrylate oligomer having an ether bond can be synthesized, for example, by adding one or more 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 the hydroxyl group of an aliphatic polyether polyol or the hydroxyl group of an aromatic polyether polyol using bisphenol, etc. as raw materials, but is not limited to this method. Commercially available products include, for example, 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.), EBECRYL (registered trademark) 3700 (manufactured by Daicel Cytec Co., Ltd.), etc.

[0024] The weight average molecular weight of the (meth)acrylate oligomer is not particularly limited, but is, for example, 1,000 to 100,000, preferably 2,000 to 30,000, more preferably 3,000 to 20,000. By setting the range of the weight average molecular weight within such a range, the durability of the cured coating film can be improved while maintaining low viscosity.

[0025] ((meth)acrylate monomer) (Meth)acrylate monomers are not particularly limited as long as they have one or more (meth)acryloyl groups. The number of (meth)acryloyl groups contained in one molecule is not particularly limited, but from the viewpoints of the curability of the curable artificial nail composition, the hardness of the cured coating film, etc., it is 1 to 10, preferably 1 to 8, more preferably 1 to 6. In the present invention, it is preferable to use one or more selected from (meth)acrylate monomers having one (meth)acryloyl group as the (meth)acrylate monomer. Further, it is preferable to use 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.

[0026] (Meth)acrylate monomers having one (meth)acryloyl group include, for example, esters of monohydric alcohols 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, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, N-acryloyloxyethylhexahydrophthalimide and (meth)acrylic acid; (Meth)acryloyl group-containing amide compounds such as acrylamide, hydroxyethyl acrylamide, 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, N,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide; Hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate;Nitrogen-containing alkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N-t-butylaminoethyl (meth)acrylate; glycidyl (meth)acrylate; 4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane, adamantyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-isobutyl-2-methyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-ethyl-2-methyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (1,4-dioxaspiro[4,5]decane-2-yl)methyl (meth)acrylate, tetrafluorofurfuryl alcohol oligo (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethyl hexahydrophthalimide, pentamethylpiperidyl (meth)acrylate, di(meth)acrylate of isocyanuric acid, tri(meth)acrylate of isocyanuric acid, triazine tri(meth)acrylate, N-(meth)acryloxysuccinimide, N-(meth)acryloxyphthalimide and other heterocyclic ring-containing (meth)acrylates and the like, and one or more selected from the group consisting of;

[0027] Among the (meth)acrylate monomers having one of these (meth)acryloyl groups, esters of monohydric alcohols 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, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, etc. with (meth)acrylic acid, and one or more selected from the group consisting of hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, etc. are preferred.

[0028] 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 propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,9-nonanediol 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, bisphenol A ethylene oxide modified di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate (such as isopyridenediphenyl bis(oxyhydroxypropyl methacrylate)), propoxylated ethoxylated bisphenol A di(meth)acrylate, and other di(meth)acrylate monomers; tri(meth)acrylate monomers such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, trimethylolpropane propylene oxide modified tri(meth)acrylate, trimethylolpropane ethylene oxide modified tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ε-caprolactone modified tris(acryloxyethyl) isocyanurate; tetra(meth)acrylate monomers such as pentaerythritol tetra(meth)acrylate;One or more selected from the group consisting of polypentaerythritol (meth)acrylates such as dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol (meth)acrylate, and tetrapentaerythritol (meth)acrylate; (meth)acrylate monomers having four or more (meth)acryloyl groups such as ethoxylated isocyanuric acid triacrylate and ethoxylated pentaerythritol tetraacrylate; etc.;

[0029] Among these (meth)acrylate monomers having two or more (meth)acryloyl groups, 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, the following formula;

Chemical formula

[0030] According to the findings of the present inventors, in the curable artificial nail composition, the temperature rise during curing is generated by the reaction of the (meth)acryloyl group and the radical. Therefore, when using a component with a high degree of polymerization (high weight average molecular weight) such as a (meth)acrylate oligomer, the number of (meth)acryloyl groups per unit mass decreases, and the number of reaction sites per unit mass decreases. As a result, it becomes possible to control (reduce) the temperature rise during curing. On the other hand, when using a polyfunctional (meth)acrylate, the temperature rise during curing tends to be high. That is, by increasing the degree of polymerization or the content of the (meth)acrylate oligomer, the temperature rise during curing can be lowered, and by using a polyfunctional (meth)acrylate or increasing the content of a (meth)acrylate with a low molecular weight, the temperature rise during curing can be increased.

[0031] In the curable artificial nail composition of the present invention, the content of the polymerizable compound is 70 to 99.5% by mass, preferably 80 to 99.5% by mass. Further, the content of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound is 0 to 100% by mass, preferably 10 to 100% by mass, more preferably 20 to 100% by mass, based on the total amount of the polymerizable compounds in the curable artificial nail composition. In the curable artificial nail composition of the present invention, the content of the (meth)acrylate oligomer is 0 to 100% by mass, preferably 30 to 90% by mass, more preferably 40 to 80% by mass, based on the total amount of the polymerizable components in the curable artificial nail composition. In the curable artificial nail composition of the present invention, the content of the (meth)acrylate monomer is 0 to 100% by mass, preferably 10 to 70% by mass, more preferably 20 to 60% by mass, based on the total amount of the polymerizable components in the curable artificial nail composition.

[0032] In the curable artificial nail composition of the present invention, by reducing the content of the acryloyl group-containing polymerizable compound, for example, to 30% by mass or less, preferably 29% by mass, with respect to the total 100% by mass of all components of the curable composition, the temperature rise during curing can be controlled and can be made 23°C or lower. ! The curable artificial nail composition of the present invention can lower the temperature rise during curing by setting the content of the acryloyl group-containing polymerizable compound within a specific range with respect to 100% by mass in total of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound in the curable artificial nail composition. In addition, the curable artificial nail composition of the present invention can lower the temperature rise during curing by setting the content of the acryloyl group-containing polymerizable compound within a specific range with respect to 100% by mass in total of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound in the curable artificial nail composition and controlling the weight average molecular weight of the methacryloyl group-containing polymerizable compound. As a result, the temperature rise during curing of the curable artificial nail composition of the present invention can be, for example, 23°C or lower, preferably 20°C or lower, more preferably 15°C or lower.

[0033] <Polymerization initiator> The polymerization initiator generates radicals when energy is applied by irradiation with light (e.g., ultraviolet light) or heat. For example, one or more polymerization initiators selected from the group consisting of acylphosphine oxide-based, α-hydroxyalkylphenone-based, benzoin ether-based, benzyl ketal-based, acid ester-based, α-aminoalkylphenone-based, benzophenone-based, thioxanthone-based, titanocene-based, quinone-based, peroxide-based, azo-based, persulfate-based, etc. can be mentioned. For example, when a photoinitiator is used, good curability can be imparted even when the curable artificial nail composition is irradiated with light using various light sources including a UV-LED light source.

[0034] For example, the acylphosphine oxide-based polymerization initiator generates radicals by irradiation with ultraviolet light having a wavelength of 365 to 405 nm emitted from a generally used UV-LED light source. Therefore, good curability can be imparted to the curable composition even when curing is performed by irradiating light using various light sources including a UV-LED light source. Furthermore, when curing is performed by irradiating light using a UV-LED light source, yellowing of the cured coating film can be prevented. Examples of acylphosphine oxide-based polymerization initiators 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, and the like. In particular, 2,4,6-trimethylbenzoyldiphenylphosphine oxide can also function as a skin conditioning agent and can therefore be preferably used in the present invention.

[0035] Examples of polymerization initiators other than acylphosphine oxide-based polymerization initiators include 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE184), 1-(4-(phenylthio)-2,2-(O-benzoyloxime)) 1-hydroxycyclohexyl phenyl 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-methyl-propan-1-one, 2-hydroxy-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-oxy]-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-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 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(methyl isobutyrate), 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, dilauroyl peroxide, disuccinic acid peroxide, dibenzoyl peroxide, t-butyl peroxypivalate, t-butyl peroxybenzoate, t-hexyl peroxide parelate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-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-trimethylcyclohexane, 2,2-bis(t-butylperoxy)butane, 2,One or more selected from the group consisting of 2-bis(t-butylperoxy)octane, dicetyl peroxydicarbonate, t-hexyl peroxyisopropyl monocarbonate, diisopropyl peroxydicarbonate, t-butyl peroxyisopropyl carbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, potassium persulfate, sodium persulfate, ammonium persulfate, etc. can be mentioned.,

[0036] In the present invention, it is preferable to use a polymerization initiator containing an acylphosphine oxide-based polymerization initiator, and it is preferable to use a polymerization initiator containing an acylphosphine oxide-based polymerization initiator and an α-hydroxyalkylphenone-based polymerization initiator. Further, a polymerization initiator containing an acylphosphine oxide-based polymerization initiator, an α-hydroxyalkylphenone-based polymerization initiator, and a peroxide-based polymerization initiator can also be used.

[0037] In the curable artificial nail composition of the present invention, the content of the polymerization initiator is 0.05 to 20.0% by mass, preferably 0.05 to 18.0% by mass, more preferably 0.07 to 16.0 parts by mass, and still more preferably 0.1 to 15.0% by mass with respect to the total amount of the constituent components of the curable artificial nail composition. If the content exceeds 20.0% by mass, the molecular weight of the cured coating film may decrease and the cured coating film may become brittle, and the cured coating film of the curable artificial nail composition may turn yellow. If the content is less than 0.05% by mass, it may take time to cure the curable artificial nail composition, and there is a risk of poor curing.

[0038] <Other components> In the curable artificial nail composition, various additives can be blended as long as they do not adversely affect the viscosity, usability, durability of the cured coating film, etc. Such additives include, for example, resins, radical polymerizable unsaturated group-containing compounds other than (meth)acrylate oligomers and (meth)acrylate monomers, colorants, polyfunctional thiol compounds, polyol compounds, fragrances, silicone-based and fluorine-based defoamers, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, polymerization accelerators such as tertiary amines, chain transfer agents, fillers, surface tension adjusters, polymerization inhibitors, solvents, flame retardants, antioxidants, ion adsorbents, low stress agents, preservatives, antibacterial agents, flexibility imparting agents, waxes, halogen trap agents, leveling agents, wetting improvers, etc. One or more selected from the group consisting of various additives can be mentioned.

[0039] The resin is not particularly limited as long as it is not a polymerizable resin and not a polyol compound. For example, one or more selected from the group consisting of polyurethane resins, polyester 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. can be mentioned.

[0040] (Meth)acrylate oligomers and radical polymerizable unsaturated group-containing compounds other than (meth)acrylate monomers are compounds having an unsaturated group capable of radical polymerization other than the (meth)acryloyl group. The unsaturated group capable of radical polymerization is a functional group having a carbon-carbon double bond (also referred to as a polymerizable double bond), and examples thereof include a vinyl group, a vinyl ether group, an allyl group, etc. For example, one or more selected from the group consisting of allyl glycidyl ether, styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, vinyl acetate, etc. can be mentioned.

[0041] The colorant includes one or more selected from the group consisting of pigments, pearlescent materials, 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, pearlescent materials, organic pigments, and dyes used in the nail coating material, and does not significantly inhibit curing by ultraviolet irradiation (light irradiation) or the like. In the uncured curable artificial nail composition, it is also possible to blend not only pigments and the like but also resin particles and decorative materials that can be blended into known curable artificial nail compositions.

[0042] Examples of the colorant include one or more selected from the group consisting of Pigment Brown 201, Pigment Black 401, Pigment Violet 201, Pigment Violet 401, Pigment Blue 1, Pigment Blue 2, Pigment Blue 201, Pigment Blue 202, Pigment Blue 203, Pigment Blue 204, Pigment Blue 205, Pigment Blue 403, Pigment Blue 404, Pigment Green 201, Pigment Green 202, Pigment Green 204, Pigment Green 205, Pigment Green 3, Pigment Green 401, Pigment Green 402, Pigment Yellow 201, Pigment Yellow 202-(1), Pigment Yellow 202-(2), Pigment Yellow 203, Pigment Yellow 204, Pigment Yellow 205, Pigment Yellow 4, Pigment Yellow 401, Pigment Yellow 402, Pigment Yellow 403-(1), Pigment Yellow 404, Pigment Yellow 405, Pigment Yellow 406, Pigment Orange 201, Pigment Orange 203, Pigment Orange 204, Pigment Orange 205, Pigment Orange 206, Pigment Orange 207, Pigment Orange 401, Pigment Orange 402, Pigment Orange 403, Pigment Red 102, Pigment Red 104-(1), Pigment Red 105-(1), Pigment Red 106, Pigment Red 2, Pigment Red 201, Pigment Red 202, Pigment Red 203, Pigment Red 204, Pigment Red 205, Pigment Red 206, Pigment Red 207, Pigment Red 208, Pigment Red 213, Pigment Red 214, Pigment Red 215, Pigment Red 218, Pigment Red 219, Pigment Red 220, Pigment Red 221, Pigment Red 223, Pigment Red 225, Pigment Red 226, Pigment Red 227, Pigment Red 228, Pigment Red 230-(1), Pigment Red 230-(2), Pigment Red 231, Pigment Red 232, Pigment Red 3, Pigment Red 401, Pigment Red 405, Pigment Red 501, Pigment Red 502, Pigment Red 503, Pigment Red 504, Pigment Red 505, Pigment Red 506, titanium oxide, iron oxide, chromium oxide, manganese violet, carbon black, metal powder, metal flake, metal oxide flake, glass flake, etc.

[0043] The polyfunctional thiol compound is formulated as a curing regulator, a crosslinking agent, and a viscosity regulator for the curable artificial nail composition. Further, by incorporating the polyfunctional thiol compound into the curable artificial nail composition, the wiping property when wiping off and removing the cured coating film can be improved. Examples of the polyfunctional thiol compound include those obtained by reacting a hydroxyl group of a polyol compound such as trimethylolpropane, pentaerythritol, or dipentaerythritol with a compound having a thiol group or a group that reacts to form a thiol group. For example, one or more 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. can be mentioned. When the polyfunctional thiol compound is contained in the curable artificial nail composition, it can be preferably contained so as to be 1.0 to 10.0% by mass.

[0044] The polyol compound has 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, phenolic polyols, etc. Among them, alkyl polyols, polyester polyols, and polyether polyols are preferred. Examples of the alkyl polyol 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, etc.

[0045] Examples of the polyester polyol include one or more selected from the group consisting of a condensation-type polyester polyol, an addition polymerization polyester polyol, a polycarbonate polyol, etc. The condensation-type polyester polyol is obtained by a condensation reaction of 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 the molecular weight is preferably from 100 to 100,000. Examples of the addition polymerization polyester polyol include polycaprolactone, and the molecular weight is preferably from 100 to 100,000. The polycarbonate polyol is synthesized by direct phosgenation of a polyol, a transesterification method using diphenyl carbonate, etc., and the molecular weight is preferably from 100 to 100,000. Examples of the polyether polyol include a polyether polyol obtained by ring-opening polymerization of an alkylene oxide.

[0046] Examples of the polymerization inhibitor include one or more selected from the group consisting of a quinone compound, salicylic acid hydrazide, a tocopherol compound, etc. When the polymerization inhibitor is contained in the curable artificial nail composition, it can be formulated so as to be 500 to 5000 ppm, preferably 1000 to 4500 ppm based on the whole curable artificial nail composition.

[0047] The solvent is not particularly limited as long as it can adjust the viscosity during coating by dilution. For example, 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; acetate esters such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol. One or more selected from the group consisting of these can be mentioned.

[0048] <Uses, physical properties, etc. of the curable artificial nail composition> The cured coating film of the curable artificial nail composition of the present invention is excellent in adhesion to the substrate, maintains the adhesion to the substrate for a long period of time, and has appropriate hardness. The curable artificial nail composition of the present invention is a composition for coating the surface of nails, like so-called general manicures and pedicures, and the surface of the user's own nails may be coated on a surface provided with irregularities by sanding or the like as necessary. It can be particularly preferably used as a gel nail, and can be used for any of, for example, a base coat layer directly applied to the user's nail, a color coat applied on the base coat layer, and a top coat layer further applied thereon. When used as a color coat, it can be used after being colored in various colors such as solid color, lame tone, metallic luster tone, dark color, and bright color using a colorant. When forming the cured coating film of the curable artificial nail composition of the present invention, the same equipment used when curing a radical polymerizable curable composition can be used, for example, general ultraviolet curing equipment or manicure curing equipment.

[0049] Since the content of unpolymerized curable components caused by polymerization inhibition by oxygen and the like in the cured coating film of the curable artificial nail composition of the present invention is suppressed, a step of wiping with a solvent such as ethanol, isopropanol, ethyl acetate, or acetone, particularly ethanol, is unnecessary. The curable artificial nail composition of the present invention can be used in any layer to prevent the cured coating film from chipping, peeling, or lifting from the underlying layer or the user's nail for a long period (for example, at least two weeks after curing).

[0050] The curable artificial nail composition of the present invention has a viscosity at 25°C of 0.1 Pa·s or more and 60.0 Pa·s or less. Preferably it is 0.5 Pa·s or more, more preferably 0.7 Pa·s or more, and 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 with excellent coating workability using coating tools such as brushes and inkjets can be obtained.

[0051] <Coating of nails using a curable artificial nail composition> The nails coated with the curable composition of the present invention may be either human fingernails or toenails, or the nails of animals such as dogs and cats. When the curable artificial nail composition of the present invention is applied and coated on a nail or a (non)cured coating film provided on a nail, sanding may or may not be performed on the application surface. The coating method of the curable artificial nail composition is not particularly limited, and for example, coating tools such as brushes and coating methods such as inkjets can be used. The curable artificial nail composition of the present invention can be used as any of the base coat layer (gel base; underlayer), intermediate layer (color layer), or top coat layer in gel nails. In particular, since it has excellent adhesion to the substrate, it is preferably used as the base coat layer (gel base; underlayer). 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 surface of the coating film of the curable artificial nail composition to enhance the design.

[0052] Also, a layer having a shape such as a nail is prepared on one side of a sheet using the uncured curable artificial nail composition of the present invention. After bringing this layer into contact (transfer) with the nail surface, the sheet can be peeled off or left unpeeled, and then irradiated with ultraviolet rays for curing. According to the method of providing a layer on the sheet surface using a curable artificial nail composition and transferring it, it is possible to coat a uniform and accurate pattern on the surface of the nail without using an applicator such as a pen, and moreover, there is no need to wash the applicator after use.

[0053] Regarding the curing means of the curable artificial nail composition after application, there is no particular limitation as long as it is a means capable of imparting energy to the curable artificial nail composition. For example, when curing by irradiating light such as ultraviolet rays, a known device for ultraviolet curing is used. Although the amount of energy required for curing varies depending on the composition of the curable artificial nail composition, for example, when curing by irradiating light such as ultraviolet rays, the irradiation energy (integrated light amount) by light irradiation is, for example, 5 mJ / cm 2 or more, preferably 10 mJ / cm 2 or more, and for example, 1000 mJ / cm 2 or less, preferably 800 mJ / cm 2 or less. If the irradiation energy is within this range, a nail art having sufficient adhesion and abrasion resistance can be obtained. As the light source for irradiating light, for example, 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 them, from the viewpoints of small size, long life, high efficiency, and low cost, ultraviolet light-emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are preferable.

Examples

[0054] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to only these examples. Unless otherwise specified, “%” means “mass %” and “part” means mass part.

[0055] <Examples 1 to 11, Comparative Examples 1 to 9> The components shown in Table 1 and Table 2 were put into a container so as to have the quantitative ratios (parts by mass) shown in Table 1 and Table 2, and while stirring with a dissolver, the mixture was heated to 50 °C and stirred. After stirring, it was left standing at 80 °C for 2 hours to defoam, and a curable artificial nail composition was obtained. All of these steps were carried out under light shielding.

[0056] The components in Table 1 and Table 2 are as follows, respectively. (Oligomer) PUA-1: Polyether polyurethane methacrylate obtained from hydroxyethyl methacrylate, isophorone diisocyanate and polycarbonate diol PUA-2: Polyether polyurethane methacrylate obtained from hydroxyethyl methacrylate, isophorone diisocyanate and polypropylene glycol (PPG#2000) (Non-reactive polymer) PU1: Polyurethane resin (Polymerization initiator) HCPK: 1-Hydroxycyclohexyl phenyl ketone TPO: 2,4,6-Trimethylbenzoyl diphenylphosphine oxide TBPB: tert-Butyl benzoyl peroxide (Additive) SiO2: Dimethyldichlorosilane surface-treated hydrophobic fumed silica (AEROSIL R972; manufactured by Nippon Aerosil Co., Ltd.) (Rheology modifier) BHT: Dibutylhydroxytoluene (Polymerization inhibitor) EL: Ethyl lactate (Solvent)

[0057] (Methacrylate monomer) HBMA: 2-Hydroxybutyl methacrylate TMPMA: Trimethylolpropane trimethacrylate PHME: Mixture containing ethyl hexanoate methacrylate and bis(ethyl hexanoate methacrylate) phosphate n-LM: n-Lauryl methacrylate IBXMA: Isobornyl methacrylate BPA-DGEM: Bisphenol A diglycidyl ether methacrylic acid adduct (Acrylate monomer) HEAA: Hydroxyethyl acrylamide IBXA: Isobornyl acrylate DMAA: Dimethylacrylamide PMA: Mixture containing 2-acryloyloxyethyl phosphate and bis(2-hydroxypropyl methacrylate) phosphate

[0058] The measurement of the temperature rise during curing of the obtained curable artificial nail composition was carried out as follows. The results are shown together in Table 1 and Table 2. (Measurement of temperature rise during curing) The heat of curing generated during curing was measured by a temperature measuring device attached to a curing shrinkage meter (trade name Custron; manufactured by Acro Edge). The samples used for the measurement of the heat of curing were prepared as follows. A substrate fixing jig was provided on the ultraviolet light source, and a transparent glass substrate was fixed to the substrate fixing jig. A hole with a diameter of 1.0 mm was drilled in a Teflon (registered trademark) plate to prepare a Teflon ring. The prepared Teflon ring was placed on the transparent glass substrate, and the curable artificial nail composition was filled into the perforated part so that the film thickness before curing was 1.0 ± 0.1 mm. Then, the Teflon ring was covered with a light-shielding material (black aluminum foil) to prepare a sample. The sample was irradiated with ultraviolet light from the transparent glass substrate side to cure the curable artificial nail composition filled in the perforated part of the Teflon ring, and the heat of curing generated during curing was measured.

[0059] (Calculation of temperature rise during curing) Using the obtained heat of curing, the following formula (A): Temperature rise during curing (°C) = Maximum value of heat of curing (°C) - Measurement start temperature (°C) was used to calculate the temperature rise during curing.

[0060]

Table 1

[0061] [Table 2]

[0062] The curable artificial nail compositions of Examples 1 and 2 were both excellent in adhesion of the cured coating film to the substrate (adhesion to the nail), adhesion persistence, curability, aesthetic appearance of the cured coating film, etc., and could be used as gel nails without problems. From Tables 1 and 2, it can be seen that as the content of the acryloyl group-containing polymerizable compound in the polymerizable compound increases, the temperature rise during curing becomes higher. Also, from Tables 1 and 2, it can be seen that when the content of the acryloyl group-containing polymerizable compound is 30% by mass or less, preferably 29% by mass or less, based on 100% by mass of the total of all components of the curable artificial nail composition, the temperature rise during curing becomes about 23°C or less.

Claims

**Claim 1** A curable artificial nail composition having a temperature rise during curing of 17.8 °C or less and a viscosity at 25 °C of 0.1 Pa·s or more and 60.0 Pa·s or less, which contains an acryloyl group-containing polymerizable compound, a methacryloyl group-containing polymerizable compound, and a polymerization initiator, wherein the content of the acryloyl group-containing polymerizable compound is 20% by mass or less based on 100% by mass in total of the acryloyl group-containing polymerizable compound and the methacryloyl group-containing polymerizable compound in the curable artificial nail composition, and the content of the acryloyl group-containing polymerizable compound is 0% by mass or more and 30% by mass or less based on 100% by mass in total of all components of the curable artificial nail composition. **Claim 2** The curable artificial nail composition according to Claim 1, which contains one or more urethane methacrylate oligomers, one or more acylphosphine oxide-based polymerization initiators, and an esterified product of one or more monohydric alcohols and (meth)acrylic acid.

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