JP2024075935A - Curable artificial nail composition - Google Patents

Abstract

[Problem] To provide a curable artificial nail composition that can form a cured coating film that has excellent adhesion to nails, in particular peel-off strength, and that is suppressed from peeling or chipping even when used for an extended period of time after gel nail application, and has excellent curability. [Solution] A curable artificial nail composition that contains (A) a radically polymerizable compound having a phosphate group, (B) a radically polymerizable compound other than a radically polymerizable compound having a phosphate group, (C) phosphoric acid, and (D) a polymerization initiator. [Selected Figure] None

Description

The present invention relates to a curable artificial nail composition.

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

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

Until now, curable artificial nail compositions such as gel nails have been developed that satisfy requirements such as adhesion of the cured coating film to the substrate (adhesion to the nail), adhesion duration, curability, and aesthetic appearance of the cured coating film. However, further improvements in the properties of the curable artificial nail compositions to date have been required in terms of adhesion of the cured coating film to the substrate (adhesion to the nail) and adhesion duration. Furthermore, curable artificial nail compositions are also required to have properties such as curability and aesthetic appearance of the cured coating film.

Patent Document 1 discloses an artificial nail compound that includes (a) a compound having at least one radically polymerizable unsaturated double bond in the molecule, (b) an acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule, and (c) a radical polymerization initiator.
Patent Document 2 describes the following components (A) to (D):
Disclosed is an artificial nail raw material composition that can be hardened by photopolymerization, comprising: (A) a radically polymerizable compound having one or more radically polymerizable unsaturated bonds in one molecule; (B) a silane coupling agent having one or more radically polymerizable unsaturated bonds in one molecule; (C) at least one of a phosphate ester having one or more radically polymerizable unsaturated bonds in one molecule and a phosphite ester having one or more radically polymerizable unsaturated bonds in one molecule; and (D) a photopolymerization initiator.
Patent Document 3 describes the following components (A) to (C):
Disclosed is an artificial nail raw material composition comprising: (A) a radically polymerizable compound having one or more radically polymerizable unsaturated bonds in one molecule; (B) at least one of an alkylene oxide adduct and a polyalkylene oxide adduct of (meth)acrylic acid having one or more (excluding the case of two) (meth)acryloyl groups in one molecule and having two or more oxyalkylene groups per (meth)acryloyl group in one molecule; and (C) a photopolymerization initiator, wherein the content of component (B) is 1 to 30 mass% of the total mass of components (A) and (B), and the content of an acidic phosphorus compound is 0 to 30 mass% of the total mass of components (A) and (B).

JP 2010-053097 A Patent No. 5636533 Japanese Patent No. 6656662

The curable artificial nail compositions described in Patent Documents 1 to 3 are said to be capable of forming a cured coating film that has excellent adhesion to human nails. However, peeling or chipping may occur during use, making it necessary to perform the gel nail treatment again within a short period of time, and the adhesiveness to nails is still not satisfactory.
The problem to be solved by the present invention is to provide a curable artificial nail composition that is capable of forming a cured coating film that has excellent adhesion to nails, in particular peel-off strength, and that is suppressed from peeling or chipping even when used for a long period of time after gel nail application, and has excellent curability.

Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that the above problems can be solved by providing a curable artificial nail composition having a specific composition, thereby completing the present invention.
Specifically, the following applies:
[Item 1] A curable artificial nail composition comprising: (A) a radically polymerizable compound having a phosphate group; (B) a radically polymerizable compound other than a radically polymerizable compound having a phosphate group; (C) phosphoric acid; and (D) a polymerization initiator.
[Item 2] The curable artificial nail composition according to Item 1, wherein the (B) radical polymerizable compound other than the radical polymerizable compound having a phosphate group includes a urethane (meth)acrylate oligomer.

The present invention has the remarkable effect of forming a cured coating film that has excellent adhesion to nails, particularly peel-off strength, and that is less likely to peel or chip even when used for a long period of time after gel nail application, thereby providing a curable artificial nail composition with excellent curing properties.

The mechanism by which the curable artificial nail composition of the present invention is capable of forming a cured coating film that has excellent adhesion to nails, in particular peel off strength, and that is suppressed from peeling or chipping even when used for an extended period of time after gel nail application, and thus has excellent curability, is unknown, but the present inventors speculate as follows.
In the curable artificial nail composition of the present invention, the nail surface is activated by phosphoric acid, so that the polarity of the nail surface is increased, and the nail surface with increased polarity and the cured coating film containing a monomer having a phosphoric acid group exhibit a chemical interaction, which improves the adhesion between the nail surface and the cured coating film, particularly improves the peel-off strength, and thus makes it possible to form a cured coating film that is suppressed from peeling or chipping even when used for a long period of time. However, the present invention is not limited to this speculation.

The curable artificial nail composition of the present invention will now be described.
In this specification, "(meth)acrylate" means both "acrylate" and "methacrylate", and "(meth)acryloyl" means both "acryloyl" and "methacryloyl".

[(A) Radically polymerizable compound having a phosphoric acid group]
The (A) radically polymerizable compound having a phosphate group, which is a component of the curable artificial nail composition of the present invention, is not particularly limited as long as it is a compound having a phosphate group ((-) _nP (=O)(OH) _3-n group; n is an integer of 1 to 3, and (-) is a bond of a phosphorus atom) and a radically polymerizable group in the molecule. The radically polymerizable group is not particularly limited, and examples thereof include ethylenically unsaturated groups, such as a (meth)acryloyl group, a vinyl group, a vinyl ether group, and an allyl group.
In the present invention, the (A) radical polymerizable compound having a phosphoric acid group is preferably a (meth)acrylate compound having a phosphoric acid group. Examples of the (A) radical polymerizable compound having a phosphoric acid group include compounds represented by the following formula:
(CH ₂ ═CR ¹¹ —COO—R ¹² —) _n P(═O)(OH) _3-n
(In the formula, R ¹¹ is hydrogen or a methyl group, and when there are multiple R ¹¹ , they may be the same as or different from each other. R ¹² is a divalent organic group, and when there are multiple R ¹² , they may be the same as or different from each other. n is an integer of 1 to 3.)
The compound may be one or more selected from the group consisting of compounds represented by the following formula (I):

Examples of (meth)acrylate compounds having such a phosphate group include 2-(meth)acryloyloxyethyl phosphate, 2-(meth)acryloyloxypropyl phosphate, 3-(meth)acryloyloxypropyl phosphate, 2-(meth)acryloyloxybutyl phosphate, 4-(meth)acryloyloxybutyl phosphate, 2-(meth)acryloyloxypentyl phosphate, 5-(meth)acryloyloxypentyl phosphate, 2-(meth)acryloyloxyhexyl phosphate, 6-(meth)acryloyloxyhexyl phosphate, (2-(meth)acryloyloxyethyl caprolactone phosphate), (meth)acryloyloxyethyl valerate phosphate, (meth)acryloyloxypropyl valerate phosphate, and phosphate. (Meth)acryloyloxybutyl valerate, (meth)acryloyloxypentyl valerate, (meth)acryloyloxyhexyl valerate, (meth)acryloyloxyethyl caproate, (meth)acryloyloxypropyl caproate, (meth)acryloyloxybutyl caproate, (meth)acryloyloxypentyl caproate, (meth)acryloyloxyhexyl caproate, (meth)acryloyloxyethyl caprylate, (meth)acryloyloxypropyl caprylate, (meth)acryloyloxybutyl caprylate, (meth)acryloyloxypentyl caprylate, (meth)acryloyloxyhexyl caprylate, (meth)acryloyloxyethyl caprylate, (meth)acryloyloxypropyl caprylate, (meth)acryloyloxybutyl caprylate, (meth)acryloyloxypentyl caprylate, (meth)acryloyloxyhexyl caprylate Sil, bis(2-(meth)acryloyloxyethyl) phosphate, bis(2-(meth)acryloyloxypropyl) phosphate, bis(3-(meth)acryloyloxypropyl) phosphate, bis(2-(meth)acryloyloxybutyl) phosphate, bis(4-(meth)acryloyloxybutyl) phosphate, bis(2-(meth)acryloyloxypentyl) phosphate, bis(5-(meth)acryloyloxypentyl) phosphate, bis(2-(meth)acryloyloxyhexyl) phosphate, bis(6-(meth)acryloyloxyhexyl) phosphate, bis(2-(meth)acryloyloxyethylcaprolactone) phosphate, phosphate ester of polyethylene glycol monoacrylate (acid phosphopolyoxyethylene) Examples of the phosphate ester include ethylene glycol mono(meth)acrylate, phosphate ester of polypropylene glycol monomethacrylate (acid phosphooxy polyoxypropylene glycol mono(meth)acrylate, etc.), ethylene oxide modified phosphate mono(meth)acrylate, ethylene oxide modified phosphate di(meth)acrylate, propylene oxide modified phosphate mono(meth)acrylate, propylene oxide modified phosphate di(meth)acrylate, phosphate modified epoxy(meth)acrylate, caprolactone modified phosphate mono(meth)acrylate, caprolactone modified phosphate di(meth)acrylate, tris(2-(meth)acryloyloxyethyl)phosphate, etc.

These (meth)acrylate compounds having a phosphate group may be commercially available products, and examples thereof include one or more selected from the group consisting of Kyoeisha Chemical's "Light Acrylate" series (P-1A(N) etc.), Kyoeisha Chemical's "Light Ester" series (P-1M, P-2M etc.), Unichemical's "Hosmer" series (M, PE, MH, PP etc.), Nippon Kayaku's "KAYAMER" series (PM2, PM-21 etc.), and Daicel-Allnex's "EBECRYL" series (168, 170, KRM8762 etc.).

In the curable artificial nail composition of the present invention, the content of the radical polymerizable compound having a phosphate group (A) is not particularly limited. For example, the content is 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 0.8% by mass or more, and for example, 10.0% by mass or less, preferably 7.0% by mass or less, more preferably 4.0% by mass or less, based on 100% by mass of the total amount of the curable artificial nail composition. If the content of the radical polymerizable compound having a phosphate group (A) exceeds 10.0% by mass, the cured coating film of the curable artificial nail composition may become cloudy over time, and the colored coating film may fade over time. If the content of the radical polymerizable compound having a phosphate group (A) is less than 0.1% by mass, the adhesiveness of the cured coating film of the curable artificial nail composition may not be sufficient.

[(B) Radically polymerizable compound other than radically polymerizable compound having a phosphoric acid group]
The radical polymerizable compound other than the radical polymerizable compound having a phosphate group (B), which is a component of the curable artificial nail composition of the present invention, is not particularly limited as long as it has a radical polymerizable group in the molecule and does not have a phosphate group. The radical polymerizable group is not particularly limited, and examples thereof include ethylenically unsaturated groups, such as (meth)acryloyl groups, vinyl groups, vinyl ether groups, and allyl groups.

In the present invention, the radical polymerizable compound other than the (B) radical polymerizable compound having a phosphoric acid group may be a (meth)acrylate compound having no phosphoric acid group or a radical polymerizable compound having no (meth)acrylate group and no phosphoric acid group. Of these, a (meth)acrylate compound having a (meth)acrylate group and no phosphoric acid group is preferred.

<(Meth)acrylate Compound Having No Phosphate Group>
The (meth)acrylate compound having no phosphoric acid group is not particularly limited as long as it is a radical polymerizable compound having one or more (meth)acrylate groups in the molecule and not having a phosphoric acid group in the molecule, and may be used alone or in combination of two or more. The number of (meth)acrylate groups contained in the molecule is not particularly limited, but is 1 to 10, preferably 1 to 8, from the viewpoints of the curability of the curable artificial nail composition and the hardness of the cured coating film. Here, the number of (meth)acrylate groups can be confirmed by analysis using infrared absorption spectroscopy (IR), nuclear magnetic resonance (NMR), gas chromatography mass spectrometry (GC/MS), etc.

Examples of the (meth)acrylate compound having no phosphoric acid group include a radical polymerizable oligomer having a (meth)acrylate group and no phosphoric acid group (hereinafter, sometimes referred to as a "(meth)acrylate oligomer") and a radical polymerizable monomer having a (meth)acrylate group and no phosphoric acid group (hereinafter, sometimes referred to as a "(meth)acrylate monomer").
In the present invention, it is preferable to use a mixture of one or more types of (meth)acrylate oligomers and one or more types of (meth)acrylate monomers as the radical polymerizable compound other than the (B) radical polymerizable compound having a phosphoric acid group.

((Meth)acrylate Oligomer)
The (meth)acrylate oligomer is not particularly limited as long as it is an oligomer having one or more (meth)acrylate groups. The number of (meth)acrylate groups contained in the molecule is not particularly limited, but is 1 to 10, preferably 2 to 8, from the viewpoints of the curability of the curable artificial nail composition, the hardness of the cured coating film, and the like.
The number of (meth)acrylate groups can be confirmed by analysis using infrared absorption spectroscopy (IR), nuclear magnetic resonance (NMR), gas chromatography/mass spectrometry (GC/MS), or the like.

When a radically polymerizable phosphate compound having an acrylate group is used as the (A) radically polymerizable compound having a phosphate group, the reactivity is high and the curing heat generated during curing is also high. For this reason, it is preferable to adjust the reactivity of the curable artificial nail composition and reduce the curing heat of the curable artificial nail composition by including a (meth)acrylate oligomer, particularly a methacrylate oligomer, which has relatively low reactivity and generates low curing heat during curing. This allows the curing heat of the curable artificial nail composition to be, for example, 45°C or less, preferably 43°C or less, and more preferably 40°C or less.

The (meth)acrylate group oligomer is not particularly limited, but examples thereof include:
a (meth)acrylate oligomer having, in its main skeleton (main chain), one or more bonds selected from the group consisting of a urethane bond, a bond resulting from a ring-opening reaction of an epoxy group, an ester bond, an ether bond, a urea bond, a carbonate bond, and an amide bond;
a (meth)acrylate oligomer having a molecular chain formed by polymerization of one or more monomers selected from the group consisting of styrene-based, (meth)acrylic-based, olefin-based, and diene-based monomers;
One or more types selected from the group consisting of the above can be mentioned.

Of these,
(a) urethane (meth)acrylate oligomer ((meth)acrylate oligomer having a urethane bond in the main skeleton);
(b) an epoxy (meth)acrylate oligomer having a molecular chain generated by a ring-opening reaction of an epoxy group;
(c) ester (meth)acrylate oligomer ((meth)acrylate oligomer having an ester bond in the main skeleton);
(d) ether (meth)acrylate oligomer ((meth)acrylate oligomer having an ether bond in the main skeleton);
The use of one or more selected from the group consisting of the above is advantageous in terms of adhesion, etc.
The (meth)acrylate oligomer may be either a commercially available product or a synthetic product. In the present invention, the curable artificial nail composition may contain one or more types of urethane (meth)acrylate oligomers from the viewpoint of adhesion to nails and durability of the curable artificial nail composition and/or its cured coating film.
In the curable artificial nail composition of the present invention, by using an oligomer having a methacrylate group and/or an oligomer having a large molecular weight as the (meth)acrylate oligomer, the curing heat of the curable artificial nail composition can be reduced.
The (meth)acrylate oligomer can also be used in combination with an oligomer other than the (meth)acrylate oligomer.

{Urethane (meth)acrylate oligomer}
The urethane (meth)acrylate oligomer can be synthesized, for example, by a method in which a polyol and a polyisocyanate are reacted to form an isocyanate group-containing urethane prepolymer, and then a compound having an active hydrogen-containing group and a (meth)acrylate group in the molecule (e.g., hydroxyalkyl (meth)acrylate, (meth)acrylic acid, etc.) is reacted therewith, but the method is not limited to this.
Examples of commercially available products include AH-600, AT-600, UA-306H, and UF-8001G (manufactured by Kyoeisha Chemical Co., Ltd.), RUA-071, RUA-003VE, RUA-075, and RUA-048 (manufactured by Asia Chemical Industry Co., Ltd.), UA-4200, UA200PA, UA-33H, UA-1100H, SUA TH1, and SUA TH2 (manufactured by Shin-Nakamura Chemical Co., Ltd.), UV-3310B (manufactured by Mitsubishi Chemical Corporation), UN-9000PEP, UN-9200A, and AU-2040 (manufactured by Tokushiki Co., Ltd.), KUA-PC2I (manufactured by KSM Co., Ltd.), and Art Resin. Examples of the antibacterial agent include, but are not limited to, one or more selected from the group consisting of UN-6303, UN-9200A, UN-900PEP (manufactured by Negami Chemical Industries, Ltd.).

When a urethane (meth)acrylate oligomer is used in a curable artificial nail composition, a cured coating film having excellent elasticity, adhesion and strength can be obtained, and therefore it is preferably used.
The one or more urethane (meth)acrylate oligomers that can be used in the present invention can be selected from those having one or more skeletons 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 skeletons of a non-aromatic polyether skeleton or a (non)aromatic polycarbonate skeleton are preferred.

For example, a urethane (meth)acrylate oligomer having one or more types of 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 then subjecting 10% or more of the total number of isocyanate groups in the urethane prepolymer to an addition reaction with the (meth)acrylic compound having a hydroxyl group.
Here, the isocyanate group-containing polyether urethane prepolymer is a product of reacting a polyol compound having an alkylene group having 3 or more carbon atoms with a polyisocyanate, and has a weight average molecular weight of, for example, 400 to 30,000. The polyol compound is preferably polypropylene polyol. The polyisocyanate may be one or more selected from the group consisting of non-aromatic polyisocyanates such as isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, their isocyanurates, and their biuret derivatives.

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

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

{Ether (meth)acrylate oligomer}
The ether (meth)acrylate oligomer having an ether bond can be synthesized, for example, by adding one or more members selected from the group consisting of a compound having a hydroxyl group and a (meth)acrylate group in the molecule, (meth)acrylic acid, and a compound having a carboxyl group and a (meth)acrylate group in the molecule to a hydroxyl group of an aliphatic polyether polyol or a hydroxyl group of an aromatic polyether polyol made from a raw material such as bisphenol, but is not limited to this method.
Examples of commercially available products include, but are not limited to, one or more selected from the group consisting of UV-6640B, UV-6100B, UV-3700B (manufactured by Mitsubishi Chemical Corporation), Light Acrylate (registered trademark) 3EG-A, 4EG-A, 9EG-A, 14EG-A, PTMGA-250, BP-4EA, BP-4PA, BP-10EA, Light Ester 4EG, 9EG, 14EG (manufactured by Kyoeisha Chemical Co., Ltd.), and EBECRYL (registered trademark) 3700 (manufactured by Daicel-Cytec Co., Ltd.).

{Weight average molecular weight of (meth)acrylate oligomer}
The weight average molecular weight of the (meth)acrylate oligomer is not particularly limited. For example, it is 1,000 or more, preferably 2,000 or more, more preferably 3,000 or more, and for example, it is 100,000 or less, preferably 30,000 or less, more preferably 20,000 or less. By setting the weight average molecular weight in such a range, it is possible to improve the durability of the cured coating film while maintaining a low viscosity.

((Meth)acrylate Monomer)
The (meth)acrylate monomer is not particularly limited as long as it has one or more (meth)acrylate groups and does not have a phosphate group in the molecule. The number of (meth)acrylate groups contained in the molecule is not particularly limited, but is 1 or more, for example 10 or less, preferably 8 or less, more preferably 6 or less, from the viewpoint of the curability of the curable artificial nail composition and the hardness of the cured coating film.
In the present invention, it is preferable to use, as the (meth)acrylate monomer, one or more types selected from (meth)acrylate monomers having one (meth)acrylate group. It is also preferable to use a mixture of one or more types selected from (meth)acrylate monomers having one (meth)acrylate group and one or more types selected from (meth)acrylate monomers having two or more (meth)acrylate groups.

Examples of (meth)acrylate monomers having one (meth)acrylate group include 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, and N-acryloyloxyethylhexahydrophthalimide with (meth)acrylic acid; acrylamide, hydroxyethylacrylamide, dimethylacrylamide, diethylacrylamide, methacrylamide, N-methyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide. N,N-dimethyl(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 (meth)acrylate group-containing amide compounds such as arylamide; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; nitrogen-containing alkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and 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-dioxolane-4yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-isobutyl-2-methyl-1,3-dioxolane-4yl)methyl (meth)acrylate, (2-ethyl-2-methyl-1,3-dioxolane-4yl)methyl (meth)acrylate, At least one selected from the group consisting of heterocyclic ring-containing (meth)acrylates such as (solan-4yl)methyl (meth)acrylate, (1,4-dioxaspiro[4,5]decane-2yl)methyl (meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, pentamethylpiperidyl (meth)acrylate, isocyanuric acid di(meth)acrylate, isocyanuric acid tri(meth)acrylate, triazine tri(meth)acrylate, N-(meth)acryloxysuccinimide, and N-(meth)acryloxyphthalimide.

Among these (meth)acrylate monomers having one (meth)acrylate group, (i) esters of monohydric alcohols and (meth)acrylic acid, 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, and isobornyl (meth)acrylate;
(ii) hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate;
It is preferable to use one or more selected from the group consisting of:

Examples of (meth)acrylate monomers having two or more (meth)acrylate 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, and the like. 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 (isopyridenediphenylbis(methacrylic acid oxyhydroxy) di(meth)acrylate monomers such as propoxylated ethoxylated bisphenol A di(meth)acrylate; 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, and ε-caprolactone modified tris(acryloxyethyl)isocyanurate; At least one selected from the group consisting of tetra(meth)acrylate monomers such as pentaerythritol tetra(meth)acrylate; polypentaerythritol (meth)acrylates such as dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol (meth)acrylate, and tetrapentaerythritol (meth)acrylate; and (meth)acrylate monomers having four or more (meth)acrylate groups such as ethoxylated isocyanuric acid triacrylate and ethoxylated pentaerythritol tetraacrylate.

で表されるプロポキシ化ビスフェノールＡジメタクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート等からなる群より選ばれる１種類以上を使用することが好ましい。 Among these (meth)acrylate monomers having two or more (meth)acrylate 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, and compounds represented by the following formula:

It is preferable to use one or more selected from the group consisting of propoxylated bisphenol A dimethacrylate represented by the formula (I), trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

(Radically polymerizable compound having no (meth)acrylate group)
The radical polymerizable compound having no (meth)acrylate group is not particularly limited. For example, one or more compounds selected from the group consisting of compounds having a radically polymerizable unsaturated group (functional group having a polymerizable carbon-carbon double bond), such as a vinyl group, a vinyl ether group, or an allyl group, may be used. Specifically, one or more compounds selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, vinyl acetate, vinyl propionate, methyl vinyl ether, ethyl vinyl ether, N-vinylpyrrolidone, vinylpyridine, allyl glycidyl ether, a vinyl group-containing oligomer, an allyl group-containing oligomer, etc. may be used.

<(B) Content of radical polymerizable compound other than radical polymerizable compound having a phosphoric acid group>
In the curable artificial nail composition of the present invention, the content of the radical polymerizable compound other than the radical polymerizable compound having a phosphate group (B) is not particularly limited. For example, the content is 50.0 mass% or more, preferably 60.0 mass% or more, more preferably 70.0 mass% or more, and for example, 98.0 mass% or less, preferably 96.0 mass% or less, more preferably 95.0 mass% or less, based on 100 mass% of the total amount of the curable artificial nail composition. If the content of the radical polymerizable compound other than the radical polymerizable compound having a phosphate group (B) exceeds 98.0 mass%, the adhesiveness of the cured coating film of the curable artificial nail composition may not be sufficient. If the content of the radical polymerizable compound other than the radical polymerizable compound having a phosphate group (B) is less than 50.0 mass%, the cured coating film of the curable artificial nail composition may become cloudy over time, and the colored coating film may fade over time.

In the curable artificial nail composition of the present invention, the radical polymerizable compound other than the radical polymerizable compound having a phosphoric acid group (B) preferably contains a (meth)acrylate oligomer and a (meth)acrylate monomer. In this case, the contents of the (meth)acrylate oligomer and the (meth)acrylate monomer are not particularly limited.
The content of the (meth)acrylate oligomer is, relative to the amount of (B) radical polymerizable compounds other than the radical polymerizable compound having a phosphate group, taken as 100 mass%, for example, 10 mass% or more, preferably 20 mass% or more, and more preferably 30 mass% or more, and can be, for example, 90 mass% or less, preferably 80 mass% or less, and more preferably 70 mass% or less.
The content of the (meth)acrylate monomer is, relative to the amount of (B) radical polymerizable compounds other than the radical polymerizable compound having a phosphoric acid group, taken as 100 mass%, for example, 10 mass% or more, preferably 20 mass% or more, and more preferably 30 mass% or more, and can be, for example, 90 mass% or less, preferably 80 mass% or less, and more preferably 70 mass% or less.

In the present invention, the curability and curing heat of the curable artificial nail composition can be adjusted by adjusting the type and amount of the radically polymerizable monomer contained in the curable artificial nail composition.
In the present invention, the use of a radically polymerizable monomer having a functional group, such as a (meth)acrylate monomer having a hydroxyl group, or a (meth)acrylate compound having a cyclic structure in the molecule, such as cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, or (meth)acryloylmorpholine, is preferred in terms of the adhesion of the cured coating film of the curable artificial nail composition to the substrate (adhesive strength to the nail), adhesion durability, curability, aesthetic appearance of the cured coating film, and the like.

[(C) Phosphate]
The phosphoric acid (C), which is a component of the curable artificial nail composition of the present invention, is at least one selected from the group consisting of _{orthophosphoric} acid ( _H3PO4 ), metaphosphoric acid ( _{HPO3 )} , polyphosphoric acid (e.g., linear condensed phosphoric acids such as _{pyrophosphoric} acid ( _H4P2O7 ) and _{tripolyphosphoric} acid ( _{H5P8O10 )} ), polymetaphosphoric acid (e.g., cyclic condensed phosphoric acids such as trimetaphosphoric acid and tetrametaphosphoric acid), phosphoric anhydride, and the like.
These can be commercially available with various purities, for example, 85% phosphoric acid, which is easily available and inexpensive, can be used. Phosphoric acid can be mixed together when the components constituting the curable artificial nail composition are mixed, or it can be mixed in advance in each of the components constituting the curable artificial nail composition.

In the curable artificial nail composition of the present invention, the content of (C) phosphoric acid is not particularly limited. For example, the content of orthophosphoric acid (H ₃ PO ₄ ) is 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and for example, 2.0% by mass or less, preferably 1.5% by mass or less, more preferably 1.2% by mass or less, based on 100% by mass of the total amount of the curable artificial nail composition. If the content of (C) phosphoric acid exceeds 2.0% by mass, the cured coating film of the curable artificial nail composition may become cloudy over time, and the colored coating film may fade over time. If the content of (C) phosphoric acid is less than 0.001% by mass, the adhesiveness of the cured coating film of the curable artificial nail composition may not be sufficient.

[(D) Polymerization initiator]
The polymerization initiator (D), which is a component of the curable artificial nail composition of the present invention, is not particularly limited as long as it generates radicals when energy is imparted thereto by irradiation with light (e.g., ultraviolet light) or heat, and can initiate polymerization of the "(A) radically polymerizable compound having a phosphoric acid group" and the "(B) radically polymerizable compound other than the radically polymerizable compound having a phosphoric acid group". Examples of the polymerization initiator include one or more polymerization initiators selected from the group consisting of acylphosphine oxides, α-hydroxyalkylphenones, benzoin ethers, benzil ketals, acid esters, α-aminoalkylphenones, benzophenones, thioxanthones, titanocenes, quinones, peroxides, azos, and persulfates.
For example, when a photopolymerization initiator is used, good curability can be imparted to the curable artificial nail composition even when the composition is irradiated with light using various light sources including a UV-LED light source.

For example, an acylphosphine oxide-based 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 the composition is cured by irradiating light using various light sources including a UV-LED light source, the curable composition can be imparted with good curability. Furthermore, when the composition is cured by irradiating light using a UV-LED light source, yellowing of the cured coating film can be prevented.
Examples of the acylphosphine oxide polymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide. Examples of the suitable phosphine oxide include one or more selected from the group consisting of bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis-(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, etc. In particular, 2,4,6-trimethylbenzoyldiphenylphosphine oxide can be preferably used in the present invention since it also functions as a skin conditioning agent.

For example, the α-hydroxyalkylphenone polymerization initiator may be one or more selected from the group consisting of 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-1-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, and thioxanthone.

Examples of polymerization initiators other than acylphosphine oxide polymerization initiators and α-hydroxyalkylphenone polymerization initiators include 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-benzylthioxanthone, 2-methyl ... 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-diphenylethan-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, benzo benzyl isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, benzil 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) dihydrochloride, 2,2'-azobis(isobutyronitrile), 2,2'-azobis-2-methylbutyronitrile, 1,1-azobis(1-cyclohexanecarbonitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(methylisobutyrate), t-butyl hydroperoxide, cumene hydroperoxide, diacetyl peroxide, didecanoyl peroxide, di-t-butyl peroxide, methyl ethyl ketone peroxide, cyclo Hexanone 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 parylate, 2,5-dimethyl-2,5-di(2-ethylhexanoyl) peroxide, butylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, n-butyl-4,4-di(t-butylperoxy)valerate, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)-3,3,5-trimethyl Examples of the peroxydicarbonate include one or more selected from the group consisting of cyclohexane, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, dicetyl peroxydicarbonate, t-hexylperoxyisopropyl monocarbonate, diisopropyl peroxydicarbonate, t-butylperoxyisopropyl carbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, potassium persulfate, sodium persulfate, and ammonium persulfate.

In the curable artificial nail composition of the present invention, it is preferable to use a polymerization initiator that can generate radicals and initiate polymerization at ultraviolet wavelengths of around 405 nm and around 365 nm that are irradiated during curing, and it is more preferable to use a polymerization initiator that contains an acylphosphine oxide-based polymerization initiator. In the present invention, it is even more preferable to use a polymerization initiator that contains an α-hydroxyalkylphenone-based polymerization initiator in addition to the acylphosphine oxide-based polymerization initiator. It is also possible to use a polymerization initiator composition that contains an acylphosphine oxide-based polymerization initiator and a peroxide-based polymerization initiator.

In the curable artificial nail composition of the present invention, the content of the polymerization initiator (D) is not particularly limited. For example, the content is 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, relative to the total amount of the curable artificial nail composition (100% by mass), and is, for example, 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less. If the content of the polymerization initiator (D) exceeds 15.0% by mass, the cured coating film of the curable artificial nail composition may become brittle or may turn yellow (yellowing). If the content of the polymerization initiator (D) is less than 0.05% by mass, the curing of the curable artificial nail composition may take a long time, and may result in poor curing.

In the curable artificial nail composition of the present invention, when a polymerization initiator containing an acylphosphine oxide-based polymerization initiator and an α-hydroxyalkylphenone-based polymerization initiator is used as the polymerization initiator (D), the content of the acylphosphine oxide-based polymerization initiator is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, and more preferably 1.0% by mass or more, relative to 100% by mass of the total amount of the curable artificial nail composition, and the content of the α-hydroxyalkylphenone-based polymerization initiator is, for example, 1.0% by mass or more, preferably 2.0% by mass or more, and more preferably 3.0% by mass or more, relative to 100% by mass of the total amount of the curable artificial nail composition, and for example, 14.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less. In this case, the total content of the acylphosphine oxide polymerization initiator and the α-hydroxyalkylphenone polymerization initiator is, for example, 4.0% by mass or more, for example, 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 10.0% by mass or less, based on 100% by mass of the total amount of the curable artificial nail composition. If the content of the acylphosphine oxide polymerization initiator exceeds 14.0% by mass, the cured coating film of the curable artificial nail composition may become brittle or may turn yellow (yellowing). If the content of the acylphosphine oxide polymerization initiator is less than 0.05% by mass, the curing heat of the curable artificial nail composition may become high, and the temperature rise during curing may become large.

[(E) Other Components]
In addition to the above (A) to (D), various components can be blended as "(E) other components" in the curable artificial nail composition of the present invention, within a range that does not adversely affect the cured coating film adhesion, cured coating film durability, viscosity, handleability, storage stability, coatability, curability, etc.
(E) Examples of other components include one or more types selected from the group consisting of various additives such as resins, colorants, polyfunctional thiol compounds, polyol compounds, polymerization inhibitors, solvents, fragrances, silicone-based and fluorine-based defoamers, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, photopolymerization accelerators such as tertiary amines, chain transfer agents, surface tension adjusters, flame retardants, antioxidants, ion adsorbents, stress reducers, preservatives, antibacterial agents, flexibility imparting agents, waxes, halogen trapping agents, leveling agents, wetting improvers, and decorative materials.

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

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

Examples of colorants include Brown No. 201, Black No. 401, Purple No. 201, Purple No. 401, Blue No. 1, Blue No. 2, Blue No. 201, Blue No. 202, Blue No. 203, Blue No. 204, Blue No. 205, Blue No. 403, Blue No. 404, Green No. 201, Green No. 202, Green No. 204, Green No. 205, Green No. 3, Green No. 401, Green No. 402, Yellow No. 201, Yellow No. 202-(1), Yellow 202 No.-(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, Red No. 506, titanium oxide, iron oxide, chromium oxide, manganese violet, carbon black, metal powder, metal flakes, metal oxide flakes, glass flakes, etc.

The polyfunctional thiol compound is blended as a curability regulator, a crosslinking agent, and a viscosity modifier in the curable artificial nail composition. In addition, by blending the polyfunctional thiol compound in 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 thiol group or a compound having a group that becomes a thiol group upon reaction with a hydroxyl group of a polyol compound such as trimethylolpropane, pentaerythritol, dipentaerythritol, etc. For example, one or more compounds selected from the group consisting of trimethylolpropane tris(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), etc. may be mentioned.
When the polyfunctional thiol compound is contained in the curable artificial nail composition, it is preferable that the polyfunctional thiol compound be contained in an amount of 1.0 to 10.0% by mass.

The polyol compound functions as a diluent and an adhesion improver for the curable artificial nail composition. Examples of the polyol compound include one or more selected from the group consisting of alkyl polyols, polyester polyols, polyether polyols, acrylic polyols, polybutadiene polyols, and phenolic polyols. Among these, alkyl polyols, polyester polyols, and polyether polyols are preferred.
The alkyl polyol may be at least one selected from the group consisting of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, cyclohexanedimethanol, trimethylolpropane, pentaerythritol, and the like.

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

The polymerization inhibitor may be, for example, one or more selected from the group consisting of quinone compounds, salicylic acid hydrazide, tocopherol compounds, and the like.
When the polymerization inhibitor is contained in the curable artificial nail composition, it can be blended in an amount of 500 to 5000 ppm, preferably 1000 to 4500 ppm, based on the total amount of the curable artificial nail composition.

The solvent is not particularly limited as long as it is capable of adjusting the viscosity at the time of application by dilution. For example, one or more types selected from the group consisting of alcohols such as methanol, ethanol, propanol, n-butanol, and i-butanol; ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; cellosolves such as ethyl cellosolve; aromatic hydrocarbons such as toluene and xylene; glycol ethers such as propylene glycol monomethyl ether; acetate esters such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol.

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

[Uses of the curable artificial nail composition]
The curable artificial nail composition of the present invention is a composition for coating the surface of the nail, like common manicures and pedicures.

The curable artificial nail composition of the present invention can be particularly suitably used as a gel nail, and whether it is used to form a base coat layer (gel base; undercoat layer) applied directly to the user's nail, an intermediate layer (color coat layer) applied on the base coat layer, or a top coat layer applied thereon, the cured coating film will not chip or peel off for a long period of time (e.g., at least two weeks after curing), and the occurrence of lifting on the lower layer or the user's nail can be suppressed. When used as a color coat layer, it can be used by using a colorant to tone it in a variety of colors, such as solid colors, glitter tones, metallic luster tones, dark colors, bright colors, etc.
The curable artificial nail composition of the present invention is particularly suitable for use as a base coat layer (gel base; foundation layer) since it has excellent adhesion to nails.
After the curable artificial nail composition of the present invention is applied and before it is cured, small ornaments, powder, etc. can be attached to the coating surface of the curable artificial nail composition to enhance the design.

There are no particular limitations on the device or means used for curing the curable artificial nail composition of the present invention after application (forming a cured coating film).
The apparatus may be the same as that used for curing a radically polymerizable curable composition, such as a general ultraviolet curing apparatus or a nail polish curing apparatus.
The means is not particularly limited as long as it is a means capable of imparting energy to cause the curing of the curable artificial nail composition. Examples of the means include irradiation with energy rays such as light (ultraviolet rays (UV) etc.), electron beams, and heat. In particular, curing by irradiation with ultraviolet rays (UV) can be preferably used because it can be performed relatively quickly and easily. When curing by irradiation with light such as ultraviolet rays, a known ultraviolet curing device 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 irradiation with light such as ultraviolet rays, the irradiation energy (integrated light amount) by light irradiation is, for example, 5 mJ/ ^cm2 or more, preferably 10 mJ/ ^cm2 or more, and, for example, 1000 mJ/ ^cm2 or less, preferably 800 mJ/ ^cm2 or less. If the irradiation energy is within this range, nail art having sufficient adhesion and abrasion resistance can be obtained.

As a light source for irradiating light, for example, a known ultraviolet light source such as a mercury lamp, a metal halide lamp, an ultraviolet light emitting diode (UV-LED), an ultraviolet laser diode (UV-LD), etc. can be used. Among these, ultraviolet light emitting diodes (UV-LED; wavelength 385-415 nm; peak wavelength approximately 405 nm) and ultraviolet laser diodes (UV-LD) are preferred from the viewpoints of small size, long life, high efficiency, and low cost.

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

The curable artificial nail composition of the present invention can be used to prepare an uncured coating layer having the shape of a nail or the like on at least one surface of a sheet, and after contacting (transferring) this layer with the nail surface, the sheet can be peeled off or not, and then the layer can be cured by applying energy (e.g., irradiating with ultraviolet light, etc.).
By using a method in which an uncured coating layer is first formed on the sheet surface using a curable artificial nail composition and then this is transferred, it is possible to coat the nail surface with a uniform and accurate pattern without using an applicator such as a brush, and there is no need to wash the applicator after use.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[Examples 1 to 6, Comparative Examples 1 to 7]
The components shown in Tables 1 and 2 were placed in a vessel in the amounts (parts by mass) shown in Tables 1 and 2, and the mixture was heated to 50° C. and stirred with a dissolver.
The mixture was defoamed for 10 minutes under a pressure of 0.1 MPa while stirring, and then allowed to stand at 80° C. for 2 hours for further defoaming to obtain a curable artificial nail composition. All of these steps were performed in a dark place.

<Ingredients>
The components in Tables 1 and 2 are as follows.
PUA: Polycarbonate polyurethane methacrylate (weight average molecular weight 29,000) obtained from hydroxyethyl methacrylate, isophorone diisocyanate and polycarbonate diol
IBXA: Isobornyl acrylate IBXMA: Isobornyl methacrylate HEMA: 2-hydroxyethyl methacrylate TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide HCPK: 1-hydroxycyclohexyl phenyl ketone PM1: Mixture of 2-acryloyloxyethyl phosphate and bis(2-acryloyloxyethyl) phosphate PM2: Mixture of 2-methacryloyloxyethyl phosphate and bis(2-methacryloyloxyethyl) phosphate PM3: Mixture of mono(2-methacryloyloxyethyl caprolactone) phosphate and bis(2-methacryloyloxyethyl caprolactone) phosphate PM4: Tris(2-methacryloyloxyethyl) phosphate
PA: phosphoric acid

<Peel off load>
The adhesion of the resulting curable artificial nail composition was evaluated based on the peel-off load.
The peel-off load was measured by a 90° peel-off test as follows. The results are shown in Table 1.

(90° Peel-off test)
The surface of the nylon plate was dried at 50° C. for 24 hours or more, and then the surface was wiped with ethanol to remove dirt, and the curable artificial nail composition was applied so that the film thickness after curing was 160 μm. The composition was cured for 30 seconds with a 36 W LED light to form a cured coating film 10 mm long and 50 mm wide.
The width direction edge of the cured coating film was clamped with clips attached to a digital force gauge (Imada Corporation, ZTA-100N), and the cured coating film was peeled off from the nylon plate in the width direction at 100 mm/sec with a peel angle of 90°, and the peel-off load (the maximum load (kg) required to peel off the cured coating film) was measured.

As shown in Table 1, the curable artificial nail compositions of Examples 1 to 6 all had a peel-off load of more than 1.00 kg for the cured coating film, which meant that the load required to peel off the cured coating film was large and a cured coating film capable of suppressing the occurrence of peeling or chipping could be formed, and the compositions could be used without problems as gel nails, particularly as a gel nail base coat.
On the other hand, as shown in Table 2, when (C) phosphoric acid was not used (Comparative Examples 1, 2, and 5 to 7) and when (A) a monomer having a phosphoric acid group was not used, the peel-off load of the cured coating film was small, being less than 1.00 kg, in all cases, and there was concern about the occurrence of peeling or chipping.

Claims (2)

(A) a radical polymerizable compound having a phosphoric acid group, (B) a radical polymerizable compound other than the radical polymerizable compound having a phosphoric acid group, (C) phosphoric acid, and (D) a polymerization initiator,
A curable artificial nail composition comprising: 2. The curable artificial nail composition according to claim 1, wherein the (B) radical polymerizable compound other than the radical polymerizable compound having a phosphoric acid group includes a urethane (meth)acrylate oligomer.