JP2024030073A - Curable artificial nail composition - Google Patents

Abstract

To provide a curable artificial nail composition comprising a polymerization inhibitor in which the temperature rise during curing of the curable artificial nail composition is suppressed and to provide a curable artificial nail composition capable of suppressing yellowing of a cured coating film formed by curing after storage of the curable artificial nail composition in which the temperature rise during curing of the curable artificial nail composition is suppressed.SOLUTION: There is provided a curable artificial nail composition which comprises (A) a polymerizable compound containing a (meth) acrylate group having a weight average molecular weight of 5000 or more and 100000 or less, (B) a polymerization inhibitor and (C) a polymerization initiator, where the content of (B) is 0.7 mass% or more and 12.0 mass% or less based on 100 mass% of the total amount of the (A), (B) and (C).SELECTED DRAWING: None

Description

The present invention relates to a curable artificial nail composition.

Nail art, which involves decorating the natural nails of hands and feet, or attaching decorations to artificial nails, is becoming increasingly popular. Furthermore, artificial nails are formed on the nails for reinforcement to prevent the nails from cracking or peeling off due to external forces.
To decorate or strengthen the nails, resin-containing materials called manicures, pedicures, and sculptures are applied to the nails.

Recently, curable artificial nail compositions called gel nails have been attracting attention as materials used for nail decoration or reinforcement. Gel nails are curable gel-like nail coating materials (curable artificial nail compositions), and for example, those containing (meth)acrylate oligomers and (meth)acrylic monomers are known. Gel nails are applied to nails and irradiated with ultraviolet rays, causing a radical polymerization reaction and curing to form a crosslinked polymer film, which is said to be able to form a tough film that is difficult to peel off from the nails.

Until now, curable artificial nail compositions such as gel nails have been developed in terms of adhesion of the cured coating film to the base material (adhesion to the nail), adhesion sustainability, curability, aesthetic appearance of the cured coating film, etc. Studies have mainly been carried out. On the other hand, in curable artificial nail compositions, the temperature increases during curing due to the curing heat (polymerization heat) generated when the curable compound polymerizes (photopolymerizes) to form a cured coating film, giving the user a thermal sensation. Although it has been known that there is a risk of causing discomfort, detailed studies have not been conducted sufficiently.
Recently, even though cured coatings have characteristics such as adhesion to the base material (adhesion to nails), long-lasting adhesion, hardenability, and aesthetic appearance of cured coatings, users have been faced with heat pain and fear. In order to prevent nail damage, there is a growing need for curable artificial nail compositions that have a low temperature rise during curing.

For example, the following are known as curable artificial nail compositions such as gel nails.
Patent Document 1 describes a base coat composition for autonails containing a urethane acrylate oligomer, a monomer component containing at least hydroxyethyl acrylamide and 2-hydroxyethyl methacrylate, a photopolymerization initiator, and a polymer component. . This composition has been sensitively evaluated in three levels of heat during curing: 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. This composition has been sensitized and evaluated on the three levels of ``feel'', ``slightly feel'', and ``feel as heat pain'' regarding the temperature rise during curing, but the specific temperature is unknown.
Patent Document 3 describes a photocurable artificial nail composition that exhibits suppressed discoloration (yellowing) before curing and excellent transparency, excellent curability, and less discoloration (yellowing) after curing and excellent transparency. things are listed.
Patent Document 4 discloses a photocontainer containing a urethane (meth)acrylate oligomer, a trifunctional or higher polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a dye, and further contains 500 to 5000 ppm of a quinone compound polymerization inhibitor. Curable artificial nail compositions are described.
Patent Document 5 discloses that a urethane (meth)acrylate oligomer, a (meth)acrylate monomer, a polyfunctional thiol compound, a polymerization initiator, and a polymerization inhibitor are contained, and the content of the polymerization inhibitor is 500 to 5,000 ppm. Certain photocurable artificial nail compositions have been described.

Japanese Patent Application Publication No. 2018-80129 JP 2019-6689 Publication JP2022-56207A JP2018-23682A Japanese Patent Application Publication No. 2017-210456

The autonail base coat compositions and photocurable artificial nail compositions described in Patent Documents 1 to 5 do not consider controlling the temperature rise during curing by the composition. In addition, there was no study on preventing yellowing when a cured coating film was formed after the composition was stored.

After intensive study, the present inventor found that it is useful to add a polymerization inhibitor within a specific range in a curable artificial nail composition in order to reduce the temperature rise during curing. Furthermore, it has been found that by using a specific polymerization inhibitor in a curable artificial nail composition containing a polymerization inhibitor, it is possible to suppress yellowing of a cured coating film formed by curing after storage.
The problem to be solved by the first aspect of the present invention is to provide a curable artificial nail composition containing a polymerization inhibitor, in which the temperature increase during curing of the curable artificial nail composition is suppressed.
The problem to be solved by the second invention of the present invention is to suppress the temperature rise during curing of the curable artificial nail composition, and to prevent yellowing of the cured coating film formed by curing the curable artificial nail composition after storage. An object of the present invention is to provide a curable artificial nail composition capable of suppressing the above.

As a result of intensive studies to solve the above problems, the present inventors found that the above problems could be solved by creating a curable artificial nail composition with a specific composition, and thus completed the present invention.
Specifically, the details are as follows.
[Item 1] Contains (A) a (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, (B) a polymerization inhibitor, and (C) a polymerization initiator, and (A) , a curable artificial nail composition in which the content of (B) is 0.7% by mass or more and 12.0% by mass or less, where the total amount of (B) and (C) is 100% by mass.
[Item 2] The curable artificial nail composition according to Item 1, wherein (B) the polymerization inhibitor is a compound having one hydroxyl group in the molecule.

According to a first aspect of the present invention, a curable artificial nail composition containing a polymerization inhibitor is provided, in which the temperature increase during curing of the curable artificial nail composition is suppressed.
According to the second aspect of the present invention, the temperature rise during curing of the curable artificial nail composition is suppressed, and the yellowing of the cured coating film formed by curing the curable artificial nail composition after storage can be suppressed. Nail compositions are provided.

The present inventor has discovered that the mechanism by which the temperature rise during curing of a curable artificial nail composition is suppressed by using an appropriate amount of a polymerization inhibitor is that the polymerization inhibitor in the curable artificial nail composition suppresses an appropriate amount of radicals. It is surmised that by trapping, the growth reaction is controlled, and the temperature rise during curing can be suppressed while maintaining the curability of the curable artificial nail composition.
The present inventor has determined that the mechanism by which yellowing of a cured coating film formed by curing a curable artificial nail composition after storage can be suppressed is that a polymerization inhibitor having one hydroxyl group in the molecule causes the hydrogen of the hydroxyl group to detach. When the radicals are captured and the polymerization inhibiting function is expressed, the benzoquinone compound, which has a yellow color, is not formed, so it is presumed that yellowing of the cured coating film can be suppressed.
Note that the present invention is not limited to these speculations.

The curable artificial nail composition of the present invention comprises (A) a (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, (B) a polymerization inhibitor, and (C) a polymerization initiator. , and the content of (B) is 0.7% by mass or more and 12.0% by mass or less, where the total amount of (A), (B) and (C) is 100% by mass. It is a thing.

Hereinafter, (A) a (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, (B) a polymerization inhibitor, and (C) a polymerization initiator; A curable artificial nail composition in which the content of (B) is 0.7% by mass or more and 12.0% by mass or less, where the total amount of B) and (C) is 100% by mass will be described in detail.
In the specification and claims of this application, "(meth)acrylic" refers to both acrylic and methacrylic, "(meth)acryloyl" refers to both acryloyl and methacryloyl, and "(meth)acrylate" refers to both acryloyl and methacryloyl. means both acrylate and methacrylate, respectively.

[(A) (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less]
(A) A (meth)acrylate compound with a weight average molecular weight of 5,000 or more and 100,000 or less is a compound with a weight average molecular weight of 5,000 or more and 100,000 or less that has one or more (meth)acrylate groups. There are no particular restrictions, and one or more types can be used.
(A) The polyurethane (meth)acrylate compound has a weight average molecular weight of 5,000 or more and 100,000 or less. It is preferably 10,000 or more, more preferably 20,000 or more, and preferably 70,000 or less, more preferably 50,000 or less.

The number of (meth)acryloyl groups contained in the molecule of the (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less is not particularly limited. From the viewpoint of the curability of the curable artificial nail composition, the hardness of the coating film, etc., the number is one or more, preferably two or more, and for example, 10 or less, preferably 8 or less. The (meth)acryloyl group may be present at either the molecular terminal or side chain of the polyurethane (meth)acrylate compound. Preferably it is at the end of the molecule. 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.

(A) Examples of the (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less include polyurethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and polyester (meth)acrylate oligomers. , polyether (meth)acrylate oligomer, polyolefin (meth)acrylate oligomer, and the like.

(A) The (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less can be synthesized as follows, or a commercially available product can be used. good.
A polyurethane (meth)acrylate oligomer is, for example, a polyurethane oligomer having a hydroxyl group and/or an isocyanate group obtained by a reaction between a polyol and a polyisocyanate, a (meth)acrylate compound having a functional group that reacts with a hydroxyl group in the molecule, and It can be synthesized by reacting a (meth)acrylate compound having a functional group that reacts with an isocyanate group, but is not limited to this method.
Epoxy (meth)acrylate oligomers can be synthesized, for example, by reacting an epoxy compound having two or more epoxy groups with a (meth)acrylate compound having a functional group that reacts with epoxy groups, but this method It is not limited to.
A polyester (meth)acrylate oligomer is, for example, a polyester oligomer having a hydroxyl group and/or a carboxyl group obtained by a reaction between a polyol and a polycarboxylic acid or a ring-opening reaction of a cyclic polyester, and a functional group that reacts with a hydroxyl group in the molecule. It can be synthesized by reacting a (meth)acrylate compound having the following and/or a (meth)acrylate compound having a functional group that reacts with a carboxyl group, but the method is not limited to this method.

In the present invention, as (A) the (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, it is preferable to use a polyurethane (meth)acrylate oligomer having a polymer skeleton. Examples of the polymer skeleton include one or more types selected from the group consisting of a polyether skeleton, a poly(meth)acrylate skeleton, a polyolefin skeleton, a polyester skeleton, a polyurethane skeleton, a polycarbonate skeleton, and the like. Among these, those having one or more of polyether skeleton, polycarbonate skeleton, and polyester skeleton are preferred.

Examples of polyols that can be used in the synthesis of urethane (meth)acrylate compounds include polyether polyols, polycarbonate polyols, polyester polyols, polyacrylate polyols (acrylic polyols), polyurethane polyols, polyolefin polyols, alkylene polyols, etc. One or more selected types may be mentioned, but it is not limited to these.
Examples of polyisocyanates that can be used in the synthesis of urethane (meth)acrylate compounds include aliphatic polyisocyanates (hexamethylene diisocyanate, etc.), alicyclic polyisocyanates (isobornyl diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, norbornane diisocyanate, etc.), aromatic polyisocyanates (diphenylmethane diisocyanate, toluene diisocyanate, phenylene diisocyanate, etc.), aromatic aliphatic polyisocyanates (xylylene diisocyanate, etc.), dimers, trimers, biurets, allophanates of these polyisocyanates, Examples include one or more selected from the group consisting of uretdione, uretimine, isocyanurate, oxadiazinetrione, crude compound, etc., but are not limited thereto.
Examples of compounds having (meth)acrylate groups include (meth)acrylate group-containing compounds having groups (hydroxyl, carboxyl, amino, mercapto, etc.) that react with isocyanate groups (e.g., hydroxyalkyl (meth)acrylates). , acrylic acid, etc.), isocyanate group-containing (meth)acrylate group-containing compounds (for example, isocyanatoalkyl (meth)acrylate, etc.), but are not limited to these. do not have.

Commercially available polyurethane (meth)acrylate compounds having a weight average molecular weight of 5,000 to 100,000 include, for example, UA-306H, UA-306T, UA-306I, UA-510H (manufactured by Kyoeisha Chemical Co., Ltd.), RUA-071, RUA-003VE, RUA-075, RUA-048 (manufactured by Asia Chemical Industry Co., Ltd.), UV-7550B, UV-6630B, UV-7000B, UV-2000B, UV-2750B, UV-3000B, UV-3200B , UV-3300B, UV-3310B, UV-3700B, UV-6640B (manufactured by Mitsubishi Chemical Corporation), UN-9000PEP, UN-9200A, AU-2040 (manufactured by Tokushiki Corporation), KUA-PC2I, SUA TH1, SUA TH2 ( (manufactured by KSM), art resin UN-6207, UN-6304, UN-6305, UN-350, UN-7600, UN-7700, UN-9200A, UN-5500 (manufactured by Negami Kogyo), etc. One or more types can be mentioned, but the invention is not limited to these.

In the curable artificial nail composition of the present invention, the content of the (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less is the radically polymerizable compound in the curable artificial nail composition. 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, and 95% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, based on the total amount of 100% by mass. be. If the content exceeds 95% by mass, the viscosity of the curable artificial nail composition may become too high, leading to poor applicability and handling properties. If the content is less than 40% by mass, the viscosity of the curable artificial nail composition may become too low, resulting in poor applicability and handling properties, and the adhesion of the cured coating film to the base material may be insufficient. , there is a risk that the adhesion durability of the cured coating film will decrease.

[(B) Polymerization inhibitor]
The polymerization inhibitor (B) is not particularly limited as long as it is a compound that has the effect of suppressing curing caused by the polymerization initiator (C) in the curable artificial nail composition.

(B) Examples of the polymerization inhibitor include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl 4,6-dimethylphenol, and 2,6-di-tert-butylphenol. - Alkylphenol polymerization inhibitors such as butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, dibutylhydroxytoluene, 3,5-bistershaributyl-4-hydroxytoluene, p-methoxyphenol; hydroquinone , methylhydroquinone, tert-butylhydroquinone, hydroquinone monomethyl ether, benzoquinone, p-tert-butylcatechol, and other quinone polymerization inhibitors; diphenylamine, alkylated diphenylamine, N,N'-diphenyl-p-phenylenediamine, phenothiazine, etc. Amine polymerization inhibitors, N-oxyls such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl; dithiocarbamic acids such as copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate, etc. Copper-based polymerization inhibitors; tocopherol-based polymerization inhibitors such as α-tocopherol; salicylic acid-based polymerization inhibitors such as salicylic acid hydrazide; and one or more types selected from the group consisting of nitrobenzene, phenothiazine, tetramethylthiuram disulfide, etc.

(B) When a compound having one hydroxyl group in the molecule is used as the polymerization inhibitor, the effect of preventing yellowing of the cured coating formed by curing the curable artificial nail composition after storage becomes higher. Examples of compounds having one hydroxyl group in the molecule include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl4,6-dimethylphenol, and 2,6-di-tert-butylphenol. Di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, dibutylhydroxytoluene, 3,5-bistershaributyl-4-hydroxytoluene, p-methoxyphenol, 2,6-diter One or more types selected from the group consisting of shaributyl cresol, α-tocopherol, etc. can be mentioned. Among these, the group consisting of 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, dibutylhydroxytoluene, and 3,5-bis-tert-butyl-4-hydroxytoluene; It is preferable to use one or more selected types.

In the present invention, (B) a polymerization inhibitor is (A) a (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, (B) a polymerization inhibitor, and (C) a polymerization initiator. The content of the polymerization inhibitor (B) is 0.7% by mass or more and 12.0% by mass or less, assuming the total amount of the agent as 100% by mass. Preferably it is 0.8% by mass or more, more preferably 0.9% by mass or more, and preferably 11.0% by mass or less, more preferably 10.5% by mass or less.
(B) If the content of the polymerization inhibitor is less than 0.7% by mass, the storage stability of the curable artificial nail composition may decrease, and the temperature rise during curing may become high (over 23°C). There is. (B) If the content of the polymerization inhibitor exceeds 12.0% by mass, the cured coating film formed by curing the curable artificial nail composition after storage may yellow.

[(C) Polymerization initiator]
(C) The polymerization initiator generates radicals when energy is given to it by irradiation with light (for example, ultraviolet light) or heat. For example, acylphosphine oxide type, α-hydroxyalkylphenone type, benzoin ether type, benzyl ketal type, acid ester type, α-aminoalkylphenone type, benzophenone type, thioxanthone type, titanocene type, quinone type, peroxide type. , azo type, persulfate type, and the like.
For example, when a photopolymerization initiator is used, good curability can be imparted to the curable artificial nail composition even when irradiated with light using various light sources including a UV-LED light source. Can be done.

For example, an acylphosphine oxide polymerization initiator generates radicals when irradiated with ultraviolet light having a wavelength of 365 to 405 nm emitted from a commonly used UV-LED light source. Therefore, even when curing is performed by irradiating light using various light sources including a UV-LED light source, good curability can be imparted to the curable composition. 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 polymerization initiators include 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 be preferably used in the present invention since it also functions as a skin conditioning agent.

Examples of polymerization initiators other than acylphosphine oxide 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-dimethyl Amino-1-(4-morpholinophenyl)-butanone-1,2,2-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy- 2-Methylpropionyl)-benzyl]phenyl}-2-methylpropane, isophthalphenone, methyl phenylglyoxyate, butylanthraquinone, ethylanthraquinone, phenanthrenequinone, camphorquinone, benzophenone, 4-phenylbenzophenone, benzoylbenzoic acid, hydroxybenzophenone, 4,4'-bis(diethylamino)benzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t -Butyl-trichloroacetophenone, diethoxyacetophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) , 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(isobutyronitrile), 2,2' -Azobis-2-methylbutyronitrile, 1,1-azobis(1-cyclohexanecarbonitrile) 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2-cyclopropylpropio) Nitrile), 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, 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 parerate, 2,5-dimethyl-2,5 -di(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-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, 2,2-bis(t-butylperoxy)octane, dicetylperoxydicarbonate, t-hexylperoxyisopropyl monocarbonate, diisopropylperoxydicarbonate, t- One type selected from the group consisting of butyl peroxyisopropyl carbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, potassium persulfate, sodium persulfate, ammonium persulfate, etc. The above can be mentioned.

In the present invention, it is preferable to use a polymerization initiator containing an acylphosphine oxide polymerization initiator, and preferably a polymerization initiator containing an acylphosphine oxide polymerization initiator and an α-hydroxyalkylphenone polymerization initiator. is preferred. Furthermore, a polymerization initiator including an acylphosphine oxide polymerization initiator, an α-hydroxyalkylphenone polymerization initiator, and a peroxide polymerization initiator can also be used.

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, based on the total amount of the components of the curable artificial nail composition. The content is 0% by weight, more preferably 0.07 to 16.0% by weight, and even more preferably 0.1 to 15.0% by weight. 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 yellow (yellowing). There is. If the content is less than 0.05% by mass, it may take a long time to cure the curable artificial nail composition, and there is a possibility that curing may be insufficient.

[(D) Other components]
In addition to the above (A) to (C), various ingredients may be added to the curable artificial nail composition of the present invention to the extent that they do not adversely affect the viscosity, applicability, handleability, durability of the cured coating film, etc. (D) Other components".
(D) Other components include, for example, radically polymerizable compounds other than the above (A), colorants, polyfunctional thiol compounds, polyol compounds, fragrances, silicone-based or fluorine-based antifoaming agents, γ-glycidoxypropyl Silane coupling agents such as trimethoxysilane, photopolymerization accelerators such as tertiary amines, chain transfer agents, fillers, surface tension regulators, flame retardants, antioxidants, ion adsorbents, stress reducing agents, preservatives Examples of additives include one or more additives selected from the group consisting of various additives such as antimicrobial agents, antibacterial agents, flexibility imparting agents, waxes, halogen trapping agents, leveling agents, wetting improvers, resin particles, and decorative materials.

<Radical polymerizable compounds other than the above (A)>
Radically polymerizable compounds other than the above (A) are not particularly limited. For example, one or more types selected from the group consisting of (meth)acrylate compounds having a weight average molecular weight of less than 5,000, compounds having radically polymerizable unsaturated groups other than (meth)acrylate groups, etc. can be mentioned.

((meth)acrylate compound with a weight average molecular weight of less than 5,000)
The (meth)acrylate compound having a weight average molecular weight of less than 5,000 is not particularly limited as long as it has one or more (meth)acrylate groups and has a weight average molecular weight of less than 5,000. The number of (meth)acrylate groups contained in the molecule is not particularly limited, but from the viewpoint of the curability of the curable artificial nail composition, the hardness of the cured coating, etc., it is 1 or more, for example 10 or less, preferably is 8 or less, more preferably 6 or less.

One or more types of (meth)acrylate compounds having a weight average molecular weight of less than 5,000 can be used.
Examples of (meth)acrylate compounds having one (meth)acrylate group with a weight average molecular weight of less than 5,000 include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl ( meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, t-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, neopentyl(meth)acrylate, cyclohexyl(meth)acrylate, tetrahydrofurfuryl( Esterified products of monohydric alcohols and (meth)acrylic acid such as meth)acrylate, isobornyl(meth)acrylate, phenyl(meth)acrylate, benzyl(meth)acrylate, and adamantyl(meth)acrylate; acrylamide, hydroxyethyl acrylamide, dimethyl Acrylamide, diethylacrylamide, methacrylamide, N-methyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethyl (meth)acrylamide , N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylmide, N,N-diisopropyl (meth)acrylamide, N,N-dibutyl (meth)acrylamide, N,N-diisobutyl (meth)acrylamide 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, (Meth)acrylates such as N,N-didodecyl (meth)acrylamide, N,N-dioctadecyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, etc. Group-containing amide compounds; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; N,N-dimethylaminoethyl (meth)acrylate; Nitrogen-containing alkyl (meth)acrylates such as N,N-diethylaminoethyl (meth)acrylate and Nt-butylaminoethyl (meth)acrylate; N-(meth)acryloyloxyethylhexahydrophthalimide, pentamethylpiperidyl (meth) Acrylate, isocyanuric acid di(meth)acrylate, isocyanuric acid tri(meth)acrylate, triazine tri(meth)acrylate, N-(meth)acryloxysuccinimide, N-(meth)acryloxyphthalimide, etc. meth)acrylate; one type selected from the group consisting of polymer mono(meth)acrylates such as polyurethane mono(meth)acrylate, polyether mono(meth)acrylate, polyester mono(meth)acrylate, and polycarbonate mono(meth)acrylate; etc. The above can be mentioned.

Among these (meth)acrylate compounds having one (meth)acrylate group with a weight average molecular weight of less than 5,000,
(i) Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate , esterified products of monohydric alcohols and (meth)acrylic acid such as 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate,
(ii) hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate;
One or more types selected from the group consisting of are preferred.

Examples of (meth)acrylate compounds having two or more (meth)acrylate groups with a weight average molecular weight of less than 5,000 include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. ) 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, penta Erythritol 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 (isopylidene diphenylbis(oxyhydroxypropyl methacrylate), etc.), the following formula
Di(meth)acrylate monomers such as propoxylated bisphenol A dimethacrylate represented by; glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, trimethylolpropane modified with propylene oxide Tri(meth)acrylate monomers such as tri(meth)acrylate, trimethylolpropane ethylene oxide modified tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ε-caprolactone modified tris(acryloxyethyl)isocyanurate; pentaerythritol tetra Tetra (meth) acrylate monomers such as (meth) acrylate; polypenta such as dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol (meth) acrylate, tetrapentaerythritol (meth) acrylate, etc. (meth)acrylate monomers having four or more (meth)acrylate groups such as erythritol (meth)acrylate, ethoxylated isocyanuric acid triacrylate, and ethoxylated pentaerythritol tetraacrylate; polyurethane poly(meth)acrylate, polyether poly(meth) One or more types selected from the group consisting of acrylate, polymer poly(meth)acrylate such as polyester poly(meth)acrylate, and polycarbonate poly(meth)acrylate can be mentioned.

Among these (meth)acrylate compounds having two or more (meth)acrylate groups with a weight average molecular weight of less than 5,000, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, ) 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, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta It is preferable to use one or more selected from the group consisting of (meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

As the (meth)acrylate compound having a weight average molecular weight of less than 5,000, one or more types of radically polymerizable phosphoric acid compounds having an acrylate group may be used. A radically polymerizable phosphoric acid compound having an acrylate group is a radical having an acrylate group and a phosphoric acid group (-P(=O)(OH) _two groups or -P(=O)(OH)- group) in the molecule. There are no particular limitations as long as it is a polymerizable phosphoric acid compound.
For example, the following formula;
CH ₂ =CH-COO-R ¹¹ -P(=O)(OH) ₂
CH ₂ =CH-COO-R ¹² -P(=O)(OH)-R ¹³ -OCO-CH=CH ₂
(In the formula, R ¹¹ , R ¹² and R ¹³ represent a divalent organic group.)
One or more types selected from the group consisting of compounds represented by:

Examples of such radically polymerizable phosphoric acid compounds having an acrylate group having a weight average molecular weight of less than 5,000 include 2-acryloyloxyethyl phosphate, 2-acryloyloxypropyl phosphate, and 2-acryloyloxybutyl phosphate. , 2-acryloyloxypentyl phosphate, 2-acryloyloxyhexyl phosphate, acryloyloxyethyl valerate phosphate, acryloyloxypropyl valerate phosphate, acryloyloxybutyl valerate phosphate, acryloyloxypentyl valerate phosphate, phosphorus Acryloyloxyhexyl valerate, acryloyloxyethyl caproate phosphate, acryloyloxypropyl caproate phosphate, acryloyloxybutyl caproate phosphate, acryloyloxypentyl caproate phosphate, acryloyloxyhexyl caproate phosphate, capryl phosphate Acryloyloxyethyl phosphate, acryloyloxypropyl caprylate phosphate, acryloyloxybutyl caprylate phosphate, acryloyloxypentyl caprylate phosphate, acryloyloxyhexyl caprylate phosphate, bis(2-acryloyloxyethyl) phosphate, phosphoric acid Bis(2-acryloyloxypropyl), bis(2-acryloyloxybutyl) phosphate, bis(2-acryloyloxypentyl) phosphate, bis(2-acryloyloxyhexyl) phosphate, acid phosphooxypolyoxyethylene glycol mono One or more types selected from the group consisting of acrylate, acid phosphooxypolyoxypropylene glycol monoacrylate, ethylene oxide-modified phosphoric acid diacrylate, propylene oxide-modified phosphoric acid diacrylate, phosphoric acid-modified epoxy acrylate, etc. are mentioned. As the radically polymerizable phosphoric acid compound having an acrylate group, for example, a radically polymerizable phosphoric acid ester compound having an acrylate group can be used.

In the present invention, as the (meth)acrylate monomer having a weight average molecular weight of less than 5,000, one or more types selected from (meth)acrylate monomers having one (meth)acrylate group and having a weight average molecular weight of less than 5,000 are used. It is preferable to use In addition, one or more types of (meth)acrylate monomers having one (meth)acrylate group with a weight average molecular weight of less than 5,000 and two (meth)acrylate groups with a weight average molecular weight of less than 5,000. It is preferable to use a mixture with one or more selected from the above (meth)acrylate monomers.

(Compound having a radically polymerizable unsaturated group other than (meth)acrylate group)
Compounds having radically polymerizable unsaturated groups other than (meth)acrylate groups include, for example, radically polymerizable unsaturated groups such as vinyl groups, vinyl ether groups, and allyl groups (having polymerizable carbon-carbon double bonds). Compounds that have a functional group) can be mentioned.
Examples of such compounds include one or more selected from the group consisting of allyl glycidyl ether, styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, vinyl acetate, and the like.

The content of radically polymerizable compounds other than (A) in the curable artificial nail composition of the present invention can be, for example, 50% by mass or less, preferably 35% by mass or less.
Further, by adjusting the type and amount of the radically polymerizable compound other than (A) to be contained in the curable artificial nail composition, the reactivity and curing heat of the curable artificial nail composition can be adjusted.
In the present invention, radically polymerizable compounds other than (A) include radically polymerizable monomers having a functional group such as (meth)acrylate monomers having a hydroxyl group, molecules such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. The use of a (meth)acrylate compound having a cyclic structure within the curable artificial nail composition improves the adhesion of the cured coating film of the curable artificial nail composition to the substrate (adhesion/adhesiveness to the nail), long-lasting adhesion, and curability. , is preferable in terms of the aesthetic appearance of the cured coating film, etc.

<Colorant>
The colorant has the function of imparting a desired color tone, and can be blended into the curable artificial nail composition in any amount. Examples of the coloring agent include one or more types selected from the group consisting of pigments, glitter materials, dyes, colored resin particles, and the like. In particular, an artificial nail composition that is one or more selected from the group consisting of inorganic pigments, glitter materials, organic pigments, dyes, and colored resin particles used in nail coating materials, and that is curable by ultraviolet irradiation (light irradiation). It does not significantly inhibit the hardening of materials.

Examples of the coloring agent 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, and 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. 202-(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 No. 201, Orange No. 203, Orange No. 204, Orange No. 205, Orange No. 206, Orange No. 207, Orange No. 401, Orange No. 402, Orange No. 403, Red No. 102, Red No. 104-(1), Red No. 105-(1), Red No. 106, Red No. 2, Red No. 201, Red No. 202, Red No. 203, Red No. 204, Red No. 205, Red No. 206, Red No. 207, Red No. 208, Red No. 213 , Red No. 214, Red No. 215, Red No. 218, Red No. 219, Red No. 220, Red No. 221, Red No. 223, Red No. 225, Red No. 226, Red No. 227, Red No. 228, Red No. 230 - ( 1), Red 230-(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, One or more types selected from the group consisting of Red No. 506, titanium oxide, iron oxide, chromium oxide, manganese violet, carbon black, metal powder, metal flakes, metal oxide flakes, glass flakes, colored resin particles, plated resin particles, etc. can be given.

<Polyfunctional thiol compound>
The polyfunctional thiol compound is blended as a curability modifier, crosslinking agent, and viscosity modifier of the curable artificial nail composition. Furthermore, by incorporating a polyfunctional thiol compound into the curable artificial nail composition, it is possible to improve the wiping property when removing the cured coating film by wiping it off.
Examples of polyfunctional thiol compounds include those obtained by reacting a hydroxyl group of a polyol compound such as trimethylolpropane, pentaerythritol, and dipentaerythritol with a thiol group or a compound having a group that reacts to become a thiol group. It will be done. For example, trimethylolpropane tris(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), pionate), dipentaerythritol hexakis (3-mercaptopropionate), and the like.
When the polyfunctional thiol compound is blended into the curable artificial nail composition, the amount can be, for example, in the range of 1.0% by mass or more and 10.0% by mass or less, based on the entire curable artificial nail composition.

<Polyol compound>
The polyol compound functions as a diluent and 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, and the like. Among these, alkyl polyols, polyester polyols and polyether polyols are preferred.
The alkyl polyol is selected from the group consisting of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, cyclohexanedimethanol, trimethylolpropane, pentaerythritol, etc. One or more types can be mentioned.

Examples of the polyester polyol include one or more types selected from the group consisting of condensed polyester polyols, addition polymerized polyester polyols, polycarbonate polyols, and the like. Condensed polyester polyols include 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 diol compounds selected from the group consisting of adipic acid, isophthalic acid, terephthalic acid, sebacic acid, etc. It is obtained by a condensation reaction with an organic polybasic acid, and the weight average molecular weight is preferably 100 or more and 100,000 or less. Examples of the addition polymerized polyester polyol include polycaprolactone, and the weight average molecular weight is preferably 100 or more and 100,000 or less. Polycarbonate polyols are synthesized by direct phosgenation of polyols, transesterification with diphenyl carbonate, etc., and preferably have a weight average molecular weight of 100 or more and 100,000 or less.
Examples of polyether polyols include polyether polyols obtained by ring-opening polymerization of alkylene oxides.

[Applications, physical properties, etc. of curable artificial nail composition]
The curable artificial nail composition of the present invention has excellent curability, excellent storage stability, excellent adhesion of the cured coating film to the substrate, long-lasting adhesion to the substrate, and Temperature rise is suppressed, and yellowing of the cured coating film formed by curing after storage is suppressed.

The curable artificial nail composition of the present invention is a composition for coating the surface of the nail, like a so-called general manicure or pedicure, and the user can sand the surface of the user's own nail as necessary. It may also be coated on a surface with unevenness. In particular, it can be used suitably as a gel nail, and can be used, for example, as a base coat layer applied directly to the user's nails, a color coat applied on top of the base coat layer, and a top coat layer applied on top of that. can.
When used as a color coat, a coloring agent can be used to create a variety of colors such as solid color, lame tone, metallic luster tone, dark color, and bright color.
When forming a cured coating film of the curable artificial nail composition of the present invention, for example, equipment similar to conventional radical polymerizable nail polish that is cured by ultraviolet rays, etc., or general ultraviolet curing equipment may be used. Can be used.

The curable artificial nail composition of the present invention only needs to have a viscosity that allows it to be sufficiently applied with an applicator such as a brush. Further, the viscosity may be such that it can be applied by inkjet or the like.
The curable artificial nail composition preferably has a stress at break (maximum stress) in a tensile test of the cured coating of 15.0 MPa or more, more preferably 18.0 MPa or more, and preferably 20.0 MPa or more. More preferred. If it is less than 15.0 MPa, there is a risk that it will easily peel off due to rubbing.
Further, the strain rate at break of the cured coating film is preferably 95.0% or more, more preferably 97.0% or more, and even more preferably 100.0% or more.

[Nail coating using curable artificial nail composition]
The nails coated with the curable artificial nail composition of the present invention may be either human fingernails or toenails, or may be the nails of animals such as dogs and cats.
When applying the curable artificial nail composition of the present invention onto a nail or an (un)cured coating film provided on the nail, 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 applicator such as a brush or an inkjet method may be used.
The curable artificial nail composition of the present invention can be used as any of the base coat layer (gel base; foundation layer), intermediate layer (color layer), or top coat layer in gel nails. In particular, it is suitable for use as a base coat layer (gel base; underlying layer) because of its excellent adhesion to the substrate.
After applying the curable artificial nail composition of the present invention and before curing, it is also possible to attach small decorations, powder, etc. to the surface of the coating film of the curable artificial nail composition to enhance the design.
The curable artificial nail composition of the present invention, especially when used for forming a base layer, has excellent adhesion to the base material, maintains adhesion to the base material for a long period of time, and has a high resistance to tearing even when the coating film is pulled. A cured coating film with flexibility can be formed. Therefore, it is possible to provide gel nails that allow the user to peel off the nails by themselves.

A layer having the shape of a nail or the like is prepared on one side of a sheet using the curable artificial nail composition of the present invention, and after this layer is brought into contact (transferred) with the nail surface, the sheet is peeled off or removed. It can also be cured by irradiating it with ultraviolet rays.
By applying a layer using a curable artificial nail composition in advance on the sheet surface and transferring the layer, it is possible to coat the nail surface with a uniform and accurate pattern without using an applicator such as a brush. It is possible to do this, and there is no need to wash the applicator even after use.

The curable artificial nail composition after application can be cured using, for example, a known ultraviolet curing device. Although the irradiation energy required for curing varies depending on the composition of the curable artificial nail composition, the irradiation energy (integrated light amount) due to the light irradiation is 5 mJ/cm ² or more, preferably 10 mJ/cm 2 or more, and 1000 mJ/cm ² or more. cm ² or less, preferably 800 mJ/cm ² or less. If the irradiation energy is within this range, nail art with sufficient adhesion and abrasion resistance can be obtained.
As the light source, for example, an ultraviolet light source such as a mercury lamp, a metal halide lamp, an ultraviolet light emitting diode (UV-LED), or an ultraviolet laser diode (UV-LD) can be used.
Among these, ultraviolet light emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are preferred from the viewpoints of small size, long life, high efficiency, and low cost.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. In addition, unless otherwise specified, "part" means "part by mass" and "%" means "% by mass", respectively.

[Examples 1 to 4, Comparative Examples 1 to 5]
The components shown in Table 1 were put into a container so as to have the quantitative ratio (parts by mass) shown in Table 1, and the mixture was heated to 50° C. and stirred while being stirred by a dissolver. After stirring, the mixture was allowed to stand at 80° C. for 2 hours to defoam, thereby obtaining a curable artificial nail composition. These steps were all performed under light shielding.

<Ingredients>
The components in Table 1 are as follows.
PUA: Polycarbonate polyurethane methacrylate obtained from hydroxyethyl methacrylate, isophorone diisocyanate and polycarbonate diol (weight average molecular weight 29,000)
HPMA: 2-Hydroxypropyl methacrylate polymerization initiator 1: 2,4,6-trimethylbenzoyldiphenylphosphine oxide polymerization initiator 2: 1-hydroxycyclohexylphenylketone polymerization inhibitor 1: dibutylhydroxytoluene polymerization inhibitor 2: tert- Butylhydroquinone polymerization inhibitor 3: Hydroquinone polymerization inhibitor 4: Hydroquinone monomethyl ether polymerization inhibitor 5: α-tocopherol

<Evaluation>
(Temperature rise during curing)
The temperature rise during curing of the obtained curable artificial nail composition was measured as follows. The results are also shown in Table 1.
-Measurement start temperature and curing heat measurement-
A temperature measurement device during curing, which is attached to a curing shrinkage rate meter (trade name: Custron; manufactured by Acro Edge), measures the measurement start temperature, and also measures the temperature during curing, and determines the maximum temperature as the curing heat. did.
The sample used for measuring the curing heat was prepared as follows.
A substrate fixing jig was provided above the ultraviolet light source, and the transparent glass substrate was fixed to the substrate fixing jig.
A hole with a diameter of 1.0 mm was bored in a fluororesin plate to produce a fluororesin ring.
The prepared fluororesin ring was placed on a transparent glass substrate, and the perforated part was filled with a curable artificial nail composition to a film thickness of 1.00±0.05 mm before curing. A sample was prepared by covering it with a light-shielding material (black aluminum foil).
The curable artificial nail composition filled in the perforated portion of the fluororesin ring was cured by irradiating ultraviolet rays from the transparent glass substrate side of the sample, and the curing heat generated during curing was measured.
Using the obtained curing heat, the following formula:
Temperature rise during curing (℃) = Maximum curing heat (℃) - Measurement start temperature (℃)
The temperature increase during curing was calculated. The evaluation results are also shown in Table 1. A temperature below 23.0°C is a pass.

(Curing immediately after preparation)
After the curing heat was measured, the sample was touched with a finger from above the light-shielding material after the fluororesin ring was removed, and evaluated based on the following criteria. The evaluation results are also shown in Table 1. Evaluation C is a failure.
A: I don't feel any elasticity.
B: Slight elasticity felt.
C: Elasticity is felt/Uncured resin leaks and adheres to fingers.

(Yellowing during curing immediately after preparation)
A curable artificial nail composition having the composition shown in Table 1 was prepared, and immediately after preparation, it was applied to the white part of a hiding rate test paper so that the film thickness after curing was 320 μm. The coated surface was irradiated with an LED lamp having a peak illuminance of 110-115 mW/cm ² for 30 seconds to form a cured coating film. Using a spectrophotometer, the b ^* values of the coating film before irradiation (uncured coating film) and the cured coating film immediately after irradiation were measured. The difference Δb ^* between the b ^* value of the coating film before irradiation and the b ^* value of the cured coating film was defined as the degree of yellowing, and evaluation was performed according to the following criteria. The evaluation results are also shown in Table 1. Evaluation C is a failure.
A:Δb ^* ≦5.0
C:Δb ^* >5.0

(yellowing during curing after storage)
A curable artificial nail composition having the composition shown in Table 1 was prepared, and after being stored at 50° C. for 10 days, it was applied to the white part of a hiding rate test paper so that the film thickness after curing was 320 μm. The coated surface was irradiated with an LED lamp having a peak illuminance of 110-115 mW/cm2 for 30 seconds to form a cured coating film. Using a spectrophotometer, the b* values of the coating film before irradiation (uncured coating film) and the cured coating film immediately after irradiation were measured. The difference Δb* between the b* value of the coating film before irradiation and the b* value of the cured coating film was defined as the degree of yellowing, and evaluation was performed according to the following criteria. The evaluation results are also shown in Table 1. Evaluation C is a failure.
A: Δb*≦5.0
C:Δb*>5.0

As can be seen from the Examples and Comparative Examples in Table 1, the curable artificial nail composition of the present invention suppresses the temperature rise during curing, and the yellow color of the cured coating film formed by curing the curable artificial nail composition after storage. It can be seen that the changes are suppressed.

Claims (2)

(A) a (meth)acrylate group-containing polymerizable compound having a weight average molecular weight of 5,000 or more and 100,000 or less, (B) a polymerization inhibitor, and (C) a polymerization initiator,
A curable artificial nail composition in which the content of (B) is 0.7% by mass or more and 12.0% by mass or less, where the total amount of (A), (B), and (C) is 100% by mass. The curable artificial nail composition according to claim 1, wherein the polymerization inhibitor (B) is a compound having one hydroxyl group in the molecule.