Artificial nail composition

Abstract

The present invention provides an artificial nail composition capable of suppressing surface stickiness after curing while also suppressing curing heat, and eliminating the need for wiping after curing. This artificial nail composition is characterized by including a urethane (meth)acrylate (A component), a (meth)acrylic monomer (B component) having two polymerizable unsaturated groups, and a photopolymerization initiator (C component), wherein the urethane (meth)acrylate (A component) includes a structure derived from a polycarbonate polyol (a-1) having a ring structure, an isocyanate (a-2), and a hydroxy(meth)acrylate (a-3), and the polycarbonate polyol (a-1) has oxygen in the ring structure thereof.

Description

artificial nail composition

[0001] The present invention relates to artificial nail compositions.

[0002] In recent years, photocurable artificial nail compositions known as gel nails have been attracting attention. These artificial nail compositions are used to strengthen and decorate natural nails. The artificial nail composition contains, for example, a urethane acrylate oligomer and an acrylic monomer. After application to the nail, the artificial nail composition is irradiated with, for example, ultraviolet light. The compounds contained in the artificial nail composition are crosslinked by a radical polymerization reaction. As a result, an artificial nail coating is formed.

[0003] Artificial nails are known in which three gels are applied to the nail in this order: base gel, color gel, and top gel. Each gel is applied one layer at a time and cured with light. The top gel, which is the outermost layer, is required to reduce surface stickiness after curing. If stickiness remains after curing, a process to remove the stickiness is required. This process involves wiping the artificial nail surface with a solvent, which is called wiping. It is known that stickiness can be reduced by using, for example, a multifunctional (meth)acrylate (acrylic monomer) with three or more functional groups (see, for example, Patent Document 1). However, artificial nail compositions using such multifunctional (meth)acrylates tend to generate a large amount of heat during curing. It has been difficult to simultaneously reduce the heat of curing and the stickiness of the cured surface.

[0004] Japanese Patent Application Laid-Open No. 2018-23682

[0005] The present invention solves the above problems and aims to provide an artificial nail composition that can suppress the heat of curing, can suppress stickiness of the surface after curing, and does not require wiping after curing.

[0006] The artificial nail composition of the present invention comprises a urethane (meth)acrylate (component A), a (meth)acrylic monomer having two polymerizable unsaturated groups (component B), and a photopolymerization initiator (component C). The urethane (meth)acrylate (component A) comprises a structure derived from a polycarbonate polyol (a-1) having a ring structure, an isocyanate (a-2), and a hydroxy (meth)acrylate (a-3). The polycarbonate polyol (a-1) is characterized by having oxygen within the ring structure.

[0007] According to the present invention, it is possible to provide a non-wipe type artificial nail composition that can suppress heat generation during curing and also suppress stickiness of the surface after curing.

[0008] Conventionally, gels that do not require wiping after curing contain tri- or higher-functional polyfunctional (meth)acrylates. However, the use of tri- or higher-functional polyfunctional (meth)acrylates tends to generate high curing heat, which inevitably affects the nail and surrounding skin. Furthermore, gels that reach high temperatures upon curing are not popular with users. The inventors of the present application have discovered an artificial nail composition that has excellent curing properties (reduced stickiness) that do not require wiping and can also suppress curing heat, without using tri- or higher-functional polyfunctional (meth)acrylates, by combining a urethane (meth)acrylate (component A) and a (meth)acrylic monomer (component B) as described below.

[0009] <Constituents of Artificial Nail Composition> The artificial nail composition of the present invention contains at least a urethane (meth)acrylate (component A), a (meth)acrylic monomer having two polymerizable unsaturated groups (component B), and a photopolymerization initiator (component C). The urethane (meth)acrylate (component A) contains a structure derived from a polycarbonate polyol (a-1) having a ring structure, an isocyanate (a-2), and a hydroxy (meth)acrylate (a-3). The polycarbonate polyol (a-1) constituting the urethane (meth)acrylate (component A) contains oxygen within the ring structure.

[0010] By using a urethane (meth)acrylate (component A) containing a structure derived from the polycarbonate polyol (a-1), stickiness after curing can be suppressed. Furthermore, by using a bifunctional (meth)acrylic monomer (component B), curing heat can be suppressed. Therefore, an artificial nail composition can be obtained that is free from stickiness after curing and generates less reaction heat during curing than when a trifunctional or higher functional acrylic monomer is used. Furthermore, the O (oxygen) in the ring structure exhibits hydrophilicity, resulting in the effect of making it difficult for bacteria to adhere (bacterial repellency, low bacterial adhesion).

[0011] The polycarbonate polyol (a-1) is preferably a polyol obtained by reacting at least one diol selected from isosorbide, isomannide, and isoidide.

[0012] In this way, by using the polycarbonate polyol (a-1) derived from a diol having an alicyclic skeleton, it is possible to suppress stickiness after curing even when a bifunctional (meth)acrylic monomer (component B) is used.

[0013] Furthermore, it is preferable that the artificial nail composition contains the structure derived from the polycarbonate polyol (a-1) in an amount of 13% by weight or more and 32% by weight or less based on the total weight of the artificial nail composition.

[0014] By including the structure derived from the polycarbonate polyol (a-1) within the above range, it is easy to obtain an artificial nail composition that can suppress stickiness after curing and curing heat.

[0015] The (meth)acrylic monomer (component B) preferably has an alicyclic skeleton.

[0016] Since the component B also has a highly planar alicyclic skeleton, the artificial nail composition is less sticky after curing and requires less heat of curing.

[0017] The isocyanate (a-2) preferably has an alicyclic skeleton or an aromatic ring.

[0018] This makes it possible to more effectively suppress stickiness after curing, and also to obtain an artificial nail composition that has low shrinkage and good reactivity.

[0019] The R value of the urethane (meth)acrylate (component A) is preferably in the range of 1.5 or more and 2.0 or less.

[0020] When the R value (number of isocyanate groups / number of hydroxyl groups) is within the above range, an artificial nail composition that can suppress stickiness and curing heat after curing is easily obtained. Moreover, an artificial nail composition that has appropriate viscosity and high leveling properties is easily obtained.

[0021] The content of the urethane (meth)acrylate (component A) is preferably 29% by weight or more and 57% by weight or less based on the total amount of the components constituting the artificial nail composition.

[0022] By including the structure derived from the polycarbonate polyol (a-1) within the above range, an artificial nail composition can be obtained that can sufficiently suppress stickiness after curing.

[0023] In this specification, "urethane (meth)acrylate" means one or both of urethane acrylate and urethane methacrylate. "hydroxy (meth)acrylate" means one or both of hydroxy acrylate and hydroxy methacrylate. "(meth)acrylate" means one or both of acrylate and methacrylate.

[0024] Each of the above components will be described in detail below.

[0025] (1) Urethane (meth)acrylate (Component A) In the present invention, the urethane (meth)acrylate (Component A) contains a structure derived from a polycarbonate polyol (a-1) having a ring structure, an isocyanate (a-2), and a hydroxy(meth)acrylate (a-3).

[0026] (1-1) Polycarbonate polyol (a-1) The polycarbonate polyol (a-1) has a ring structure and contains oxygen within the ring structure. Because of this structure, even when combined with a bifunctional acrylic monomer, non-wipe (no wiping removal work is required) is achieved. The polycarbonate polyol (a-1) preferably has a number average molecular weight of about 800, and is preferably a polycarbonate polyol in the range of 500 to 2000. The polycarbonate polyol (a-1) is preferably a polyol obtained by reacting at least one diol selected from isosorbide, isomannide, and isoidide. These polycarbonate polyols include, for example, "BENEBiOL" (registered trademark) HS0830B (butanediol-isosorbide copolymer polycarbonate diol, manufactured by Mitsubishi Chemical Corporation, Mn: 800, containing 30 mol% isosorbide groups), "BENEBiOL" (registered trademark) HS0840B (butanediol-isosorbide copolymer polycarbonate diol, manufactured by Mitsubishi Chemical Corporation, Mn: 800, containing 40 mol% isosorbide groups), % content), "BENEBiOL" (registered trademark) HS0840H (hexanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 40 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation), "BENEBiOL" (registered trademark) HS0850H (hexanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 50 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation). Use of a polycarbonate polyol (a-1) having isosorbide groups is preferred because it makes the artificial nail composition hard and tack-free (non-sticky) after curing. One type of polycarbonate polyol (a-1) may be used. Alternatively, two or more types of polycarbonate polyols (a-1) may be used in combination.

[0027] The amount of polycarbonate polyol (a-1) contained in the raw material composition of urethane (meth)acrylate (component A) is, for example, 39% by weight or more and 63% by weight, preferably 42% by weight or more and 60% by weight, and more preferably 45% by weight or more and 57% by weight, relative to the raw material composition of urethane (meth)acrylate (component A).

[0028] (1-2) Isocyanate (a-2) The isocyanate (a-2) is a compound having an isocyanate group. Examples of the isocyanate (a-2) that can be used include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate dimer, p-xylylene diisocyanate, m-xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, 4,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI), norbornene diisocyanate, lysine diisocyanate, a reaction product of 1 mole of a diol with 2 moles of a diisocyanate, and an isocyanurate polyisocyanate, biuret polyisocyanate, or adduct polyisocyanate derived from a difunctional isocyanate. However, the isocyanates are not limited to the above.

[0029] As the isocyanate (a-2), it is preferable to use an alicyclic isocyanate having an alicyclic skeleton or an aromatic isocyanate having an aromatic ring. Examples of alicyclic isocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) (IPDI) and 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI). Examples of aromatic isocyanates include p-xylylene diisocyanate, m-xylylene diisocyanate, and diphenylmethane diisocyanate. The use of an alicyclic isocyanate or an aromatic isocyanate can reduce the stickiness of the artificial nail composition after curing. As a result, the artificial nail composition can be easily prepared. As the isocyanate (a-2), only one type of isocyanate (a-2) may be used. Alternatively, two or more types of isocyanates (a-2) may be used in combination. The isocyanate (a-2) may contain isocyanates other than alicyclic isocyanates or aromatic isocyanates (for example, aliphatic isocyanates). However, the main component of the isocyanate (a-2) contained in the raw material for the urethane (meth)acrylate (component A) is preferably an alicyclic isocyanate or an aromatic isocyanate. The amount of isocyanate (a-2) contained in the raw material composition for the urethane (meth)acrylate (component A) is preferably within the range of, for example, 13% by weight or more and 32% by weight or less, preferably 16% by weight or more and 29% by weight or less, and more preferably 19% by weight or more and 26% by weight or less, relative to the raw material composition for the urethane (meth)acrylate (component A).

[0030] (1-3) Hydroxy(meth)acrylate (a-3) The raw material composition of urethane (meth)acrylate (component A) contains a (meth)acrylate having a hydroxy group (OH group). Examples of the hydroxy(meth)acrylate (a-3) include hydroxypropyl methacrylate (HOP(N)), hydroxypropyl acrylate, hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyethyl acrylamide (HEAA), N-hydroxyethyl (meth)acrylamide, 3-butanediol (meth)acrylate, 1,4-butanediol (meth)acrylate, 1,6-hexanediol (meth)acrylate, 3-methylpentanediol (meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. As the hydroxy(meth)acrylate (a-3), only one type of hydroxy(meth)acrylate (a-3) may be used. Alternatively, two or more types of hydroxy(meth)acrylate (a-3) may be used in combination. The hydroxy(meth)acrylate (a-3) functions as a diluent, and increasing the amount of this component can reduce the viscosity of the urethane(meth)acrylate (component A). The amount of hydroxy(meth)acrylate (a-3) contained in the raw material composition of the urethane(meth)acrylate (component A) is preferably within the range of, for example, 11% by weight or more and 26% by weight or less, preferably 14% by weight or more and 23% by weight or less, and more preferably 17% by weight or more and 20% by weight or less, relative to the raw material composition of the urethane(meth)acrylate (component A).

[0031] The R value of the urethane (meth)acrylate (component A) is preferably in the range of 1.5 to 2.0. The R value is the molar ratio of isocyanate groups to hydroxyl groups. The measured number average molecular weight of a urethane (meth)acrylate (component A) having an R value within this range is in the range of 10,000±5,000. An artificial nail composition having an R value within this range has good adhesion to natural nails, hardness that does not crack even when bent, and conformability. The content of the urethane (meth)acrylate (component A) is 29% by weight to 57% by weight, preferably 32% by weight to 54% by weight, and more preferably 35% by weight to 51% by weight, based on the total amount of the components of the artificial nail composition.

[0032] (2) (Meth)acrylic Monomer Having Two Polymerizable Unsaturated Groups (Component B) The (meth)acrylic monomer having two polymerizable unsaturated groups (Component B) is a bifunctional reactive diluent. Because it is bifunctional, it is less likely to generate heat during curing and shrinkage is also suppressed.

[0033] The (meth)acrylic monomer (component B) preferably has an alicyclic skeleton. By having an alicyclic skeleton, tack (stickiness) after curing is suppressed. An example of the (meth)acrylic monomer (component B) is dimethylol-tricyclodecane diacrylate (DCP-A). The (meth)acrylic monomer (component B) may be obtained by reacting a compound having an alicyclic skeleton with a compound having a polymerizable unsaturated group.

[0034] The acrylic monomer (component B) may also have an aromatic ring. Examples of component B having an aromatic ring and two polymerizable unsaturated groups include FA-321A, FA-324A, FA-320M, and FA-321M (manufactured by Resonac Corporation, EO-modified bisphenol A di(meth)acrylate), Light Acrylate BP-4EAL (manufactured by Kyoeisha Chemical Co., Ltd., EO adduct diacrylate of bisphenol A), and ABE-300 and A-BPE-4 (manufactured by Shin-Nakamura Chemical Co., Ltd., alkoxylated bisphenol A acrylate).

[0035] Component B may be a (meth)acrylic monomer having two polymerizable unsaturated groups, not having an alicyclic skeleton, and not having an aromatic ring. Examples of such a (meth)acrylic monomer (component B) include 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, and neopentyl glycol diacrylate.

[0036] As the (meth)acrylic monomer (component B), only one type of (meth)acrylic monomer (component B) may be used. Alternatively, two or more types of (meth)acrylic monomers (component B) may be used in combination. The content of the (meth)acrylic monomer (component B) is, for example, 18% by weight or more and 34% by weight or less, preferably 21% by weight or more and 31% by weight or less, and more preferably 24% by weight or more and 28% by weight or less, based on 100% by weight of the entire artificial nail composition. Furthermore, the content of the (meth)acrylic monomer (component B) is, for example, 45% by weight or more and 80% by weight or less, more preferably 50% by weight or more and 75% by weight or less, based on 100% by weight of the urethane (meth)acrylate (component A).

[0037] The artificial nail composition may contain a monofunctional (meth)acrylate as a reactive diluent. Examples of the monofunctional (meth)acrylate used as a reactive diluent include hydroxypropyl methacrylate (HOP(N)), hydroxypropyl acrylate, hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyethyl acrylamide (HEAA), N-hydroxyethyl (meth)acrylamide, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, N-acryloyloxyethyl hexahydrophthalimide, and other monohydric alcohol esters with (meth)acrylic acid; amide, dimethylacrylamide, diethylacrylamide, methacrylamide, N-methyl(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 (meth)acryloyl group-containing amide compounds such as 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, and N,N-dimethylaminoethyl(meth)acrylamide;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-dioxolan-4yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-isobutyl-2-methyl-1,3-dioxolan-4yl)methyl (meth)acrylate, (2-ethyl-2-methyl-1,3-dioxolan-4yl)methyl (meth)acrylate, and (1,4-dioxaspiro[4,5]decan-2yl)methyl (meth)acrylate. and one or more selected from the group consisting of heterocycle-containing (meth)acrylates such as tetrahydrofurfuryl (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;

[0038] As for the (meth)acrylate reactive diluent, methacrylate is preferred because it generates less heat of curing than acrylate. Even among acrylates, acrylates having an alicyclic skeleton, such as isobornyl acrylate, are preferred because they generate less heat of curing than acrylates without an alicyclic skeleton. The content of the monofunctional (meth)acrylate is preferably within a range of, for example, 6.0% to 30% by weight, and preferably 9.0% to 27% by weight, based on 100% by weight of the entire artificial nail composition. When both a (meth)acrylic monomer having two polymerizable unsaturated groups (component B) and a monofunctional (meth)acrylate are included, the total content of these components is preferably within a range of, for example, 30% to 60% by weight, and preferably 35% to 54% by weight, based on 100% by weight of the entire artificial nail composition. Of the total content, component B preferably accounts for 50% by weight or more.

[0039] (3) Photopolymerization Initiator (Component C) The photopolymerization initiator (Component C) reacts with ultraviolet light or light with a wavelength of approximately 365 to 410 nm (a portion of visible light) to cure the artificial nail composition. Examples of the light source include an LED. It is preferable to use Component C, which can suppress the amount of heat generated during curing. Examples of photopolymerization initiators that can be used include benzoyl ethers, benzyl ketals, acid esters, α-aminoalkylphenones, acylphosphine oxides, benzophenones, thioxanthones, titanocenes, and oxime esters. These initiators are preferred because they do not inhibit the radical generation reaction even when absorbed by dyes, pigments, or photopolymerizable compounds, have high radical generation efficiency, and can enhance the curability of the artificial nail composition. For example, alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, titanocene-based photopolymerization initiators, and oxime ester photopolymerization initiators can be used. In particular, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is preferably used as the photopolymerization initiator (component C).

[0040] Examples of alkylphenone photopolymerization initiators include benzyl dimethyl ketal (BDK) compounds, α-hydroxyalkylphenone compounds, and α-aminoalkylphenone compounds. Examples of benzyl dimethyl ketal (BDK) photopolymerization initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one. Examples of α-hydroxyalkylphenone photopolymerization initiators include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-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, and phenylglyoxylic acid methyl ester. Examples of the α-aminoalkylphenone photopolymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone.

[0041] Examples of the acylphosphine oxide photopolymerization initiator include monoacylphosphine oxide (MAPO) compounds and bisacylphosphine oxide (BAPO) compounds. An example of a monoacylphosphine oxide (MAPO) compound is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. An example of a bisacylphosphine oxide (BAPO) compound is bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0042] An example of a titanocene photopolymerization initiator is bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium. An example of an oxime ester photopolymerization initiator is 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime).

[0043] Only one type of photopolymerization initiator (component C) among these may be used. Alternatively, two or more types of photopolymerization initiators (component C) may be used in combination. The content of the photopolymerization initiator (component C) is preferably, for example, in the range of 2.0 wt % to 9.0 wt %, more preferably in the range of 2.9 wt % to 7.3 wt %, based on 100 wt % of the total artificial nail composition.

[0044] (4) Other Components The artificial nail composition may contain additives such as oils and fats, higher alcohols, higher fatty acids, silicone oils, other oily components, silica, silane coupling agents, surfactants, fragrances, solvents such as ethanol and ethyl acetate, reaction accelerators, polymerization inhibitors, antioxidants, UV absorbers, antibacterial agents, antifungal agents, and pigments, provided that the additives do not impair the objectives of the present invention. Increasing the amount of reaction accelerator increases the rate of the curing reaction, but the artificial nail composition after curing has a structure that makes it softer. Furthermore, since the storage stability of the artificial nail composition deteriorates, adding an appropriate amount is desirable. The reaction accelerator is preferably a compound having multiple mercapto groups. For example, pentaerythritol tetrakis(3-mercaptopropionate) (PEMP, tetrafunctional) can be preferably used. Alternatively, trimethylolpropane tris(3-mercaptopropionate) (TMMP, trifunctional) or tetraethylene glycol bis(3-mercaptopropionate) (EGMP, bifunctional) may also be used. By using a trifunctional or bifunctional reaction accelerator rather than a tetrafunctional one, the amount of heat generated during the curing reaction can be effectively reduced, and storage stability can also be improved.

[0045] A purple pigment such as Purple No. 401 can also be added. Even if a portion of the artificial nail composition turns yellow, the addition of a purple pigment, which is the complementary color of yellow, can prevent the composition from appearing yellow. The amount of purple pigment added is preferably within the range of, for example, 0.0002% by weight or more and 0.002% by weight or less, with the entire artificial nail composition being 100% by weight.

[0046] Artificial nails are usually made by layering a base layer, a color layer, and a top layer in this order. The base layer constitutes the portion of the artificial nail that comes into contact with the natural nail. The color layer is decorated and determines the design of the artificial nail. The top layer is the outermost layer and functions to enhance the durability and gloss of the artificial nail. It is also possible to omit any of the base layer, color layer, and top layer. Furthermore, the artificial nail may have multiple layers selected from the base layer, color layer, and top layer. The artificial nail composition of the present invention can suppress curing heat and prevent surface stickiness after curing. Therefore, it is suitable for use in forming the top layer of an artificial nail. However, the use of the artificial nail composition of the present invention is not limited to the top layer. The base layer or color layer of an artificial nail may be formed using the artificial nail composition of the present invention.

[0047] <Method for Producing Artificial Nail Composition> The artificial nail composition according to the embodiment of the present invention can be produced, for example, by the following method.

[0048] (1) Preparation of Urethane (Meth)acrylate (Component A) Polycarbonate polyol (a-1) and isocyanate (a-2) were reacted at 80°C to 130°C for 2 hours (urethane polymerization) to obtain polyurethane (terminal -NCO groups). Hydroxy(meth)acrylate (a-3) and a polymerization inhibitor were added to the reaction mixture. Further reaction at 80°C to 100°C for 2 hours allowed the terminal -NCO groups to react with the OH groups of the hydroxy(meth)acrylate, resulting in the bonding of the hydroxy(meth)acrylate (a-3) to the polyurethane terminals. As a result, urethane (meth)acrylate (Component A) with acrylated terminals was obtained. During the second-stage reaction, it is preferable to add a polymerization inhibitor, polymerization catalyst, antioxidant, etc. Methoquinone, for example, can be used as the polymerization inhibitor. The amount added is approximately 0.1 to 0.5 wt% of the nonvolatile content.

[0049] (2) Preparation of Artificial Nail Composition The resulting urethane (meth)acrylate (component A), a (meth)acrylic monomer having two polymerizable unsaturated groups (component B), and a photopolymerization initiator (component C) are mixed together. Furthermore, a visible light stabilizer, pigment, etc. are added. The artificial nail composition is obtained by dissolving and mixing the components at room temperature to 80°C in the dark. The stabilizer is an optional component, and examples of such stabilizers include methylhydroquinone. The stabilizer is effective in preventing the artificial nail composition from naturally hardening.

[0050] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these.

[0051] Example 1 "BENEBiOL" (registered trademark) HS0840H (hexanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 40 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation) was used as the polycarbonate polyol (a-1) having oxygen in the ring structure. 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) was used as the isocyanate (a-2). Hydroxypropyl methacrylate (HOP(N)) was used as the hydroxy(meth)acrylate (a-3).

[0052] 1. Preparation of Artificial Nail Composition (1) Preparation of Urethane (Meth)acrylate (Component A) 22.54 parts of "BENEBiOL" (registered trademark) HS0840H (a-1) and 9.27 parts of 1,4-H6XDI (a-2) were reacted for 2 hours while adjusting the temperature during the reaction to fall within the range of 80°C to 130°C (urethane polymerization), to obtain a polyurethane (terminal -NCO group). The R value (molar ratio of isocyanate groups to hydroxyl groups) of the obtained polyurethane was 1.7. Furthermore, 8.11 parts of HOP(N) (a-3) and 0.080 parts of methoquinone were added, and the reaction was allowed to proceed for 2 hours while adjusting the temperature during the reaction to fall within the range of 80°C to 100°C, to obtain a terminally acrylated urethane (meth)acrylate (Component A).

[0053] (2) Preparation of Artificial Nail Composition The artificial nail composition of this example was obtained by dissolving and mixing 40 parts of urethane (meth)acrylate (component A), 30 parts of dimethyloltricyclodecane diacrylate (hereinafter referred to as DCP-A) as a (meth)acrylic monomer (component B) having an alicyclic skeleton and two polymerizable unsaturated groups, 5.5 parts of triphenylphosphine oxide (hereinafter referred to as TPO) as a photopolymerization initiator (component C), 0.22 parts of methyl hydroquinone, 0.00110 parts of pigment (Purple No. 401), 30 parts of hydroxypropyl methacrylate (hereinafter referred to as HOP(N)) as a reactive diluent, and 10 parts of pentaerythritol tetrakis(3-mercaptopropionate) (hereinafter referred to as PEMP) as a reaction accelerator at room temperature to 80° C. under a dark environment.

[0054] 2. Evaluation of Physical Properties of Artificial Nail Composition The obtained artificial nail composition was evaluated for the following physical properties. The results are shown in Table 1. The artificial nail composition of this example was rated "B" in the solvent resistance evaluation, but was rated "A" in all other items. The overall rating was "G."

[0055] (1) Leveling Property Evaluation After applying the artificial nail composition with a brush, the state was observed and evaluated according to the following criteria: A: Brush marks disappeared in less than 10 seconds B: Brush marks disappeared in 10 to less than 60 seconds C: Brush marks did not disappear in 60 seconds or more

[0056] (2) Curing Heat Evaluation One gram of artificial nail composition was dropped onto a substrate (PET film) at once. Five seconds after dropping, an irradiation device was used to irradiate the dropped artificial nail composition with LED light for 30 seconds. The irradiation device was "NAILERS' Mix Light ULM-1" (manufactured by Beauty Nailer Co., Ltd., output 48 watts, wavelength 365 nm & 405 nm). This allowed the artificial nail composition to cure. The maximum surface temperature during the 30-second irradiation was measured and evaluated according to the following criteria: A: Less than 100°C B: 100°C or higher but lower than 110°C C: 110°C or higher

[0057] (3) Curability Evaluation The artificial nail composition was applied to a substrate (PET film), spread to a thickness of 1 mm, and then cured by irradiating with LED light for 30 seconds using the irradiation device, thereby obtaining a test piece for curability evaluation. The surface of the cured artificial nail was touched with a finger and evaluated for stickiness according to the following criteria: A: No tack, no feeling of finger restraint B: No tack, but feeling of finger restraint C: Tacky

[0058] (4) Evaluation of Yellowing After Curing The artificial nail composition was applied to a substrate (PET film), spread to a thickness of 1 mm, and then cured by irradiating with LED light for 30 seconds using the irradiation device to obtain a test piece. The test piece was placed on a white paper, and the degree of yellowing of the obtained test piece was visually evaluated according to the following criteria: A: No yellowing was observed or it appeared light purple. C: Yellowing was observed.

[0059] (5) Flexibility Evaluation The artificial nail composition was applied to a substrate (PET film) and spread to a thickness of 1 mm. The composition was then cured by irradiating it with LED light for 30 seconds using the irradiation device, thereby obtaining a test piece for flexibility evaluation. The test piece was folded in half and evaluated according to the following criteria: A: No cracks; B: Cracks or whitening without cracks; C: Cracks.

[0060] (6) Solvent Resistance Evaluation An artificial nail composition was applied to a substrate (PET film), spread to a thickness of 1 mm, and then cured by irradiating with LED light for 30 seconds using the irradiation device, thereby obtaining a test piece for solvent resistance evaluation. The surface of the test piece was then wiped with cotton soaked in acetone. The condition of the test piece surface after wiping was evaluated according to the following criteria: A: No scratches, no tack; B: On the wiped surface of the test piece, the area that became cloudy after wiping was less than 50% of the entire surface, and no tack; C: On the wiped surface of the test piece, the area that became cloudy after wiping was 50% or more of the entire surface, or there was tack.

[0061] (7) Stability Evaluation 4 g of the obtained artificial nail composition (top gel) was placed in a colorless transparent sample bottle and exposed to indoor fluorescent light, and the state of change over time was evaluated. A: No hardening was observed at 120 minutes. B: Hardening was observed between 60 minutes and 120 minutes. C: Hardening was observed in less than 60 minutes.

[0062] (8) Storage Stability Evaluation The obtained artificial nail composition (top gel) was stored in a light-shielding jar at 45°C for one month. The viscosity after storage was evaluated. A: Viscosity increase or decrease of 50% or less B: Viscosity increase of more than 50% but less than 100% C: Viscosity increase of 100% or more or gelation

[0063] (9) Overall rating: G: All items are A or B. NG: There is at least one C in one item.

[0064] The artificial nail compositions of Examples 2 to 12 and Comparative Examples 1 to 6 were obtained using the compositions shown in Table 1 or Table 2 in the same manner as in Example 1.

[0065] Example 2 The artificial nail composition of this example was obtained using the same compounds as in Example 1 and the composition described in Table 1, except that "BENEBiOL" (registered trademark) HS0830B (butanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 30 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation) was used as the polycarbonate polyol (a-1) having oxygen in the ring structure. The R value of the resulting polyurethane was 1.7. The artificial nail composition of this example was rated "B" in the solvent resistance evaluation, but was rated "A" in all other categories. The overall rating was "G."

[0066] Example 3 The artificial nail composition of this example was obtained using the same compounds as in Example 1 and the composition described in Table 1, except that "BENEBiOL" (registered trademark) HS0840B (butanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 40 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation) was used as the polycarbonate polyol (a-1) having oxygen in the ring structure. The R value of the resulting polyurethane was 1.7. The artificial nail composition of this example was rated "B" in the leveling ability evaluation, but was rated "A" in all other categories. The overall rating was "G."

[0067] Example 4 The artificial nail composition of this example was obtained using the same compounds as in Example 1 and the composition described in Table 1, except that "BENEBiOL" (registered trademark) HS0850H (hexanediol-isosorbide copolymer polycarbonate diol, Mn: 800, containing 50 mol% isosorbide groups, manufactured by Mitsubishi Chemical Corporation) was used as the polycarbonate polyol (a-1) having oxygen in the ring structure. The R value of the resulting polyurethane was 1.7. The artificial nail composition of this example was rated "B" in the leveling ability evaluation, but was rated "A" in all other categories. The overall rating was "G."

[0068] Example 5 The artificial nail composition of this example was prepared in the same manner as in Example 1, except that "Art-Resin" UN906S (a urethane acrylate manufactured by Negami Chemical Industrial Co., Ltd.) was added to the urethane (meth)acrylate (component A), (meth)acrylic monomer (component B), photopolymerization initiator (component C), methylhydroquinone, pigment (Purple No. 401), reactive diluent (HOP(N)), and reaction accelerator (PEMP) obtained in Example 1, and the composition shown in Table 1 was obtained. "Art-Resin" UN906S is a second urethane (meth)acrylate (a urethane (meth)acrylate different from component A). The R value of the resulting polyurethane was 1.7. In this example, the content of the urethane (meth)acrylate (component A) was 31.69 wt % based on the total amount of components of the artificial nail composition. The R value of the resulting polyurethane was 1.7. The artificial nail composition of this example was rated "B" in the softness evaluation, but was rated "A" in all other items. The overall evaluation was "G."

[0069] Example 6 The artificial nail composition of this example was obtained by dissolving and mixing 40 parts of the urethane (meth)acrylate obtained in Example 1 (component A; the R value of the resulting polyurethane was 1.7), 30 parts of DCP-A as the (meth)acrylic monomer (component B), 5.25 parts of TPO as the photopolymerization initiator (component C), 0.21 parts of methyl hydroquinone, 0.00105 parts of a pigment (Purple No. 401), 30 parts of HOP(N) as a reactive diluent, and 5 parts of PEMP as a reaction accelerator at room temperature to 80°C in the dark. The artificial nail composition of this example was rated "B" in the curability and solvent resistance evaluations, but rated "A" in all other categories. The overall rating was "G."

[0070] Example 7 The artificial nail composition of this example was obtained by dissolving and mixing 40 parts of the urethane (meth)acrylate obtained in Example 1 (component A; the R value of the resulting polyurethane was 1.7), 30 parts of DCP-A as the (meth)acrylic monomer (component B), 3.3 parts of TPO as the photopolymerization initiator (component C), 0.22 parts of methyl hydroquinone, 0.00110 parts of a pigment (Purple No. 401), 30 parts of HOP(N) as a reactive diluent, and 10 parts of PEMP as a reaction accelerator at room temperature to 80°C under a dark environment. The artificial nail composition of this example was rated "B" in the curability evaluation and solvent resistance evaluation, but was rated "A" in all other categories. The overall rating was "G."

[0071] Example 8 The artificial nail composition of this example was obtained by dissolving and mixing 40 parts of the urethane (meth)acrylate obtained in Example 1 (component A; the R value of the resulting polyurethane was 1.7), 30 parts of DCP-A as the (meth)acrylic monomer (component B), 8.8 parts of TPO as the photopolymerization initiator (component C), 0.22 parts of methyl hydroquinone, 0.00110 parts of a pigment (Purple No. 401), 30 parts of HOP(N) as a reactive diluent, and 10 parts of PEMP as a reaction accelerator at room temperature to 80°C under a dark environment. The artificial nail composition of this example was rated "B" in the leveling ability evaluation, solvent resistance evaluation, and stability evaluation, and rated "A" in the other items. The overall rating was "G."

[0072] Example 9 The artificial nail composition of this example was obtained by dissolving and mixing 50 parts of the urethane (meth)acrylate obtained in Example 1 (component A; the R value of the resulting polyurethane was 1.7), 30 parts of DCP-A as the (meth)acrylic monomer (component B), 5.0 parts of TPO as the photopolymerization initiator (component C), 0.20 parts of methylhydroquinone, 0.00100 parts of a pigment (Purple No. 401), 10 parts of HOP(N) as a reactive diluent, and 10 parts of PEMP as a reaction accelerator at room temperature to 80°C in the dark. The artificial nail composition of this example was rated "B" in the solvent resistance evaluation, but was rated "A" in all other categories. The overall rating was "G."

[0073] Example 10: 50 parts of the urethane (meth)acrylate obtained in Example 1 (component A, the R value of the resulting polyurethane was 1.7), 10 parts of "Art-Resin" UN906S (a urethane acrylate manufactured by Negami Chemical Industrial Co., Ltd.) as a second urethane (meth)acrylate (a urethane (meth)acrylate different from component A), 30 parts of DCP-A as a (meth)acrylic monomer (component B), 5.5 parts of TPO as a photopolymerization initiator (component C), 0.22 parts of methyl hydroquinone, 0.00110 parts of a pigment (Purple No. 401), 10 parts of HOP(N) as a reactive diluent, and 10 parts of PEMP as a reaction accelerator were dissolved and mixed in a darkened environment at room temperature to 80°C to obtain the artificial nail composition of this example. In this example, the content of the urethane (meth)acrylate (component A) was 43.21 wt% based on the total amount of the components of the artificial nail composition. The artificial nail composition of this example was rated "B" in the softness evaluation, but was rated "A" in all other items. The overall evaluation was "G."

[0074] Example 11 The urethane (meth)acrylate (component A) of this example was obtained by preparation in the same manner as in Example 1, except that 23.17 parts of "BENEBiOL" (registered trademark) HS0840H (a-1), 8.41 parts of 1,4-H6XDI (a-2), and 8.34 parts of HOP(N) (a-3) were used. The R value of the resulting polyurethane was 1.5. The artificial nail composition of this example was obtained by preparing the composition shown in Table 2 using the same compounds as in Example 1, except that the component A obtained here was used. The artificial nail composition of this example was rated "B" in the leveling ability evaluation and solvent resistance evaluation, but was rated "A" in all other items. The overall rating was "G."

[0075] Example 12 The urethane (meth)acrylate (component A) of this example was obtained by preparation in the same manner as in Example 1, except that 21.66 parts of "BENEBiOL" (registered trademark) HS0840H (a-1), 10.48 parts of 1,4-H6XDI (a-2), and 7.79 parts of HOP(N) (a-3) were used. The R value of the resulting polyurethane was 2.0. The artificial nail composition of this example was obtained by preparing the composition shown in Table 2 using the same compounds as in Example 1, except that the component A obtained here was used. The artificial nail composition of this example was rated "B" in the curing heat evaluation and solvent resistance evaluation, but was rated "A" in all other items. The overall rating was "G."

[0076] Comparative Example 1 In this comparative example, trimethylolpropane triacrylate (TMP-A), a trifunctional acrylic monomer, was used instead of DCP-A ((meth)acrylic monomer (component B)). The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 and the composition shown in Table 2, prepared in the same manner as in Example 1. The R value of the obtained polyurethane was 1.7. The artificial nail composition of this comparative example was rated "C" in the curing heat evaluation and flexibility evaluation. The overall evaluation was "NG."

[0077] Comparative Example 2 In this comparative example, a trifunctional acrylic monomer "NK9300A" (manufactured by Shin-Nakamura Chemical Co., Ltd.) was used instead of DCP-A ((meth)acrylic monomer (component B)). The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 and the composition shown in Table 2, prepared in the same manner as in Example 1. The R value of the obtained polyurethane was 1.7. The artificial nail composition of this comparative example was rated "B" in the leveling ability evaluation, and "C" in the curing heat evaluation and flexibility evaluation. The overall evaluation was "NG."

[0078] The artificial nail compositions of Comparative Examples 1 and 2 experienced a rapid increase in curing heat and contraction. This is thought to be because in these comparative examples, a trifunctional acrylic monomer was used instead of the (meth)acrylic monomer (component B), resulting in excessively high reactivity.

[0079] Comparative Example 3 In this comparative example, "PTMG1,000" (a polyol having an ether skeleton, Mn: 1,000, manufactured by Mitsubishi Chemical Corporation) was used instead of the polycarbonate polyol (a-1) having oxygen in the ring structure. The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 except for the composition shown in Table 2, and prepared in the same manner as in Example 1. The R value of the obtained polyurethane was 1.7. The artificial nail composition of this comparative example was rated "C" in the curability evaluation, solvent resistance evaluation, and storage stability evaluation. The overall evaluation was "NG."

[0080] Comparative Example 4 In this comparative example, "N981" (a 1,6-polycarbonate diol with a non-alicyclic skeleton, Mn: 1,000, manufactured by Tosoh Corporation) was used instead of the polycarbonate polyol (a-1) having oxygen in the ring structure. The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 except for the above, and prepared in the same manner as in Example 1 with the composition shown in Table 2. The R value of the obtained polyurethane was 1.7. The artificial nail composition of this comparative example was rated "C" in the curability evaluation and solvent resistance evaluation. The overall evaluation was "NG."

[0081] Comparative Example 5 In this comparative example, instead of the polycarbonate polyol (a-1) having oxygen in the ring structure, "UM90 (3 / 1)" (manufactured by UBE Corporation, Mn: 900), a polycarbonate diol having a cyclic diol as the main skeleton, was used. "UM90 (3 / 1)" has a molar ratio of (cyclohexanedimethanol / hexanediol) of (3 / 1). The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 except for the composition shown in Table 2, prepared in the same manner as in Example 1. The R value of the obtained polyurethane was 1.7. The artificial nail composition of this comparative example was rated "C" in the leveling ability evaluation, curing heat evaluation, flexibility evaluation, and storage stability evaluation. The overall judgment was "NG."

[0082] Comparative Example 6 In this comparative example, instead of the polycarbonate polyol (a-1) having oxygen in the ring structure, "UM90 (1 / 1)" (manufactured by UBE Corporation, Mn: 900), a polycarbonate diol having a cyclic diol as the main skeleton, was used. "UM90 (1 / 1)" has a molar ratio of (cyclohexanedimethanol / hexanediol) of (1 / 1). The artificial nail composition of this comparative example was obtained using the same compounds as in Example 1 except for the composition shown in Table 2, and prepared in the same manner as in Example 1. The R value of the resulting polyurethane was 1.7. The artificial nail composition of this comparative example was rated "B" in the leveling ability evaluation, curability evaluation, flexibility evaluation, solvent resistance evaluation, and storage stability evaluation, and rated "C" in the curing heat evaluation. The overall evaluation was "NG."

[0083]

[0084]

[0085] As described above, it can be seen that the present invention provides an artificial nail composition that can suppress stickiness on the surface after curing and does not require wiping after curing, without using a tri- or higher functional (meth)acrylate. By not using a tri- or higher functional (meth)acrylate, the heat generated during curing is suppressed, thereby reducing the effects on the nail and surrounding skin and discomfort caused by heat during application.

Claims

1. An artificial nail composition comprising a urethane (meth) acrylate (Component A), a (meth) acrylic monomer having two polymerizable unsaturated groups (Component B), and a photopolymerization initiator (Component C), wherein the urethane (meth) acrylate (Component A) contains a structure derived from a polycarbonate polyol (a-1) having a ring structure, an isocyanate (a-2), and a hydroxy (meth) acrylate (a-3), and the polycarbonate polyol (a-1) has oxygen in the ring structure.

2. The artificial nail composition according to claim 1, wherein the polycarbonate polyol (a-1) is a polyol obtained by reacting at least one diol selected from isosorbide, isomannide, and isoidide.

3. The artificial nail composition according to claim 1 or 2, wherein the structure derived from the polycarbonate polyol (a-1) is contained in the range of 13% by weight or more and 32% by weight or less based on the total weight of the artificial nail composition.

4. The artificial nail composition according to claim 1 or 2, wherein the (meth) acrylic monomer (Component B) has an alicyclic skeleton.

5. The artificial nail composition according to claim 1 or 2, wherein the isocyanate (a-2) has an alicyclic skeleton or an aromatic ring.

6. The artificial nail composition according to claim 1 or 2, wherein the R value of the urethane (meth) acrylate (Component A) is in the range of 1.5 or more and 2.0 or less.

7. The artificial nail composition according to claim 1 or 2, wherein the content of the urethane (meth) acrylate (Component A) is 29% by weight or more and 57% by weight or less based on the total amount of the components constituting the artificial nail composition.

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