Artificial claw components

Abstract

By incorporating polyurethane having (meth)acrylamide groups as an essential component, this invention provides an artificial nail composition that ensures high removeability while possessing the performance inherently required of an artificial nail composition, namely, good adhesion between natural nails and artificial nails, and durability from curing to swelling with an organic solvent. [Solution] The artificial nail composition contains (A) a urethane (meth)acrylate oligomer or polymer having a plurality of urethane bonds in its molecular chain and (meth)acrylamide groups at at least both ends of the molecular chain, (B) an acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule, (C) a (meth)acrylic acid ester monomer, and (D) a radical polymerization initiator.

Description

Technical Field

[0001] The present invention relates to an artificial nail composition.

Background Art

[0002] A polymer obtained by copolymerizing a compound having a radically polymerizable unsaturated bond with other copolymerizable monomers has film-forming properties and is used as an artificial nail composition.

[0003] As characteristics required for an artificial nail composition, there are adhesion between natural nails and artificial nails, smoothness and gloss of the surface, durability of the film, etc. For example, (a) a compound having at least one radically polymerizable unsaturated double bond in the molecule, (b) an acidic phosphorus compound having a specific methacrylate group, and (c) an artificial nail composition containing a radical polymerization initiator have been proposed (see Patent Document 1). According to the compounds described in Patent Document 1, an artificial nail composition that satisfies these characteristics can be provided.

[0004] By the way, when an artificial nail composition is formed on a natural nail, it is necessary to remove it after a predetermined period. When removing the artificial nail composition, the surface of the artificial nail composition is polished with a coarse nail file to damage it, a wipe soaked in an organic solvent such as acetone is applied on the artificial nail composition, and it is left in a state of being wrapped with aluminum foil or the like to swell the artificial nail composition, and then the swollen artificial nail composition is peeled off using a stick-shaped instrument or the like. This method is mainly adopted. If the skill of removing the artificial nail composition is poor, there is a concern that the artificial nail composition will be shaved more than necessary and a part of the natural nail will also be shaved. Therefore, there is a demand for providing an artificial nail composition that can remove only the artificial nail composition and not shave the natural nail.

[0005] As having both flexibility and toughness and being easily repaired and removed, it has been proposed to use a polyurethane having a (meth)acrylamide group as an essential component (see Patent Document 2).

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Patent No. 7104392 [Patent Document 2] Japanese Patent Publication No. 2019-085394 [Overview of the project] [Problems that the invention aims to solve]

[0007] Indeed, using polyurethane containing (meth)acrylamide groups as an essential component improves removeability. This is thought to be because brittleness occurs when the artificial nail composition is swollen with organic solvents such as acetone. However, simply using polyurethane containing (meth)acrylamide groups as an essential component may result in inferior durability between curing and swelling with organic solvents compared to using components conventionally used as the main component in artificial nail compositions (for example, polyfunctional urethane (meth)acrylate oligomers without (meth)acrylamide groups). Therefore, there is a need to provide an artificial nail composition that ensures good adhesion between natural and artificial nails and high removeability, while also possessing durability between curing and swelling with organic solvents.

[0008] The object of the present invention is to provide an artificial nail composition that ensures high removeability by using polyurethane having (meth)acrylamide groups as an essential component, while also possessing the performance inherently required of an artificial nail composition, namely, good adhesion between natural nails and artificial nails, and durability from curing to swelling with an organic solvent. [Means for solving the problem]

[0009] The inventors of the present invention, after diligent research to solve the above problems, discovered that the above objectives can be achieved by using a specific acidic phosphorus compound and a (meth)acrylic acid ester monomer as components in combination with a polyurethane having a (meth)acrylamide group, and thus completed the present invention. Specifically, the present invention provides the following.

[0010] The invention relating to the first feature provides an artificial nail composition containing (A) a urethane (meth)acrylate oligomer or polymer having a plurality of urethane bonds in its molecular chain and (meth)acrylamide groups at at least both ends of the molecular chain, (B) an acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule, (C) a (meth)acrylic acid ester monomer, and (D) a radical polymerization initiator.

[0011] The urethane (meth)acrylate oligomer or polymer has (meth)acrylamide groups at at least both ends of its molecular chain. Therefore, it exhibits excellent swelling and brittleness when a wipe soaked in an organic solvent is applied to the artificial nail composition, allowing the artificial nail composition to be easily peeled off with minimal force using a stick-shaped tool or the like. As a result, the artificial nail composition can be removed without filing the natural nail or causing any damage to it.

[0012] Furthermore, the artificial nail composition uses a combination of a specific acidic phosphorus compound, which is component (B), and a (meth)acrylic acid ester monomer, which is component (C). By using these components (B) and (C) in combination, high toughness is obtained when the artificial nail composition is cured, and as a result, appropriate tackiness can be ensured from curing until swelling with an organic solvent, resulting in long-term durability.

[0013] As a result, according to the invention relating to the first feature, it is possible to provide an artificial nail composition that ensures high removeability while possessing the performance inherently required of an artificial nail composition, namely, good adhesion between the natural nail and the artificial nail, and durability from the time of hardening until swelling with an organic solvent.

[0014] The invention relating to the second feature provides an artificial nail composition relating to the first feature, wherein the proportion of component (A) is 30 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the artificial nail composition.

[0015] According to the invention relating to the second feature, the ease of removal can be further improved without impairing adhesiveness or durability.

[0016] The invention relating to the third feature provides an artificial nail composition relating to the first or second feature, wherein the amount of phosphoric acid contained in component (B) is 0.01 parts by mass or more and less than 7 parts by mass per 100 parts by mass of component (B).

[0017] While the inclusion of an acidic phosphorus compound in the artificial nail composition can improve adhesion between natural and artificial nails, it may become cloudy over time. According to the invention relating to the third feature, since the amount of phosphoric acid contained in component (B) is less than 7 parts by mass, clouding over time can be suppressed, thus providing not only adhesion, durability, and ease of removal but also aesthetic appeal. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an artificial nail composition that ensures the same level of adhesion and durability as when a conventional component used as the main component in an artificial nail composition (for example, a polyfunctional urethane (meth)acrylate oligomer without a (meth)acrylamide group) is used as an essential component, while also ensuring the ease of removal, which is an advantage of using polyurethane having a (meth)acrylamide group as an essential component. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 shows how, when removing gel nails, a combination of interfacial separation between the gel and the nail, cohesive fracture of the nail surface, and cohesive fracture of the gel material occurs. [Figure 2] Figure 2 illustrates a method for determining the cohesive failure rate of the nail surface. [Modes for carrying out the invention]

[0020] Hereinafter, an example of a preferred embodiment for implementing the present invention will be described with reference to the drawings. Note that this is merely an example, and the technical scope of the present invention is not limited thereto.

[0021] <Artificial nail composition> The artificial nail composition according to this embodiment contains a component (A): a urethane (meth) acrylate oligomer or polymer having a plurality of urethane bonds in the molecular chain and (meth) acrylamide groups at at least both ends of the molecular chain, a component (B): an acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule, a component (C): a (meth) acrylate monomer, and a component (D): a radical polymerization initiator.

[0022] [Component (A): Specific urethane (meth) acrylate oligomer or polymer] Component (A) has a plurality of urethane bonds in the molecular chain and (meth) acrylamide groups at at least both ends of the molecular chain.

[0023] In this embodiment, the term "(meth) acrylate" means that it can be either acrylate or methacrylate.

[0024] Component (A) preferably has one or two skeletons selected from a polycarbonate skeleton and a polyolefin skeleton. Further, component (A) is preferably a polyurethane oligomer and / or polymer having one or more (meth) acrylamide groups.

[0025] Polycarbonate and polyolefin skeletons are obtained by reacting polyols having each skeleton with polyisocyanates and compounds having (meth)acrylamide groups. Examples of polyols include polyethylene polyol, polypropylene polyol, poly-1,2-butadiene polyol, hydrogenated 1,2-polybutadiene polyol, poly-1,4-butadiene polyol, hydrogenated 1,4-polybutadiene polyol, polyisoprene polyol, hydrogenated polyisoprene polyol, and other polyolefin polyols, as well as polycarbonate polyols consisting of polyols having a linear, branched, or cyclic aliphatic hydrocarbon or heterocyclic skeleton with 1 to 12 carbon atoms and diesters of carbonate.

[0026] These polyols may be used individually or in combination of two or more types.

[0027] Furthermore, one or more polyols having a linear, branched, or cyclic aliphatic hydrocarbon or heterocyclic skeleton with 1 to 12 carbon atoms, polyether polyols, polyester polyols, polyols in which hydroxyl groups are introduced into a silicone skeleton, and polyols obtained by copolymerizing hydroxyl group-containing (meth)acrylates with other (meth)acrylic esters may be used in combination.

[0028] Examples of polyisocyanates include polyisocyanate compounds having two or more isocyanate groups in one molecule, specifically aliphatic isocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, Examples include aromatic isocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, and xylylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, methylcyclohexylene diisocyanate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate; or polymers of these, such as adduct type, isocyanurate type, and burette type.

[0029] Examples of compounds having a (meth)acrylamide group include N-hydroxy-N-methyl(meth)acrylamide, N-hydroxy-N-ethyl(meth)acrylamide, N-hydroxy-N-n-propyl(meth)acrylamide, N-hydroxy-N-isopropyl(meth)acrylamide, N-hydroxy-N-butylacrylamide, hydroxyethylacrylamide, hydroxypropyl(meth)acrylamide, hydroxybutyl(meth)acrylamide, isocyanatoethyl(meth)acrylamide, isocyanatopropyl(meth)acrylamide, and isocyanatobutyl(meth)acrylamide. However, hydroxyethylacrylamide is preferred due to its safety and ease of procurement.

[0030] Component (A) has (meth)acrylamide groups at at least both ends of its molecular chain. The number of (meth)acrylamide groups (number of functional groups) is 2 or more per molecule of component (A). This results in excellent swelling and brittleness when a wipe soaked in an organic solvent is applied to the artificial nail composition, allowing the artificial nail composition to be easily peeled off with minimal force using a stick-shaped tool or the like. Therefore, the artificial nail composition can be removed without filing the natural nail and without putting stress on the natural nail.

[0031] Furthermore, the number of (meth)acrylamide groups (functional groups) per molecule of component (A) is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. This significantly increases the photocuring speed when the artificial nail composition is applied to the natural nail to form a gel nail, and prevents excessive polymerization heat from being generated.

[0032] Component (A) may be an oligomer or a polymer, but to prevent the viscosity of the uncured material from becoming too high and preventing sufficient coating properties from being obtained, component (A) is preferably an oligomer. Generally, the weight-average molecular weight of an oligomer is usually 400 or more and 50,000 or less, and the weight-average molecular weight of a polymer is usually more than 50,000. From the viewpoint of removeability, the weight-average molecular weight of component (A) is preferably 400 or more, more preferably 1,000 or more, and even more preferably 3,000 or more. Also, from the viewpoint of coating properties, the weight-average molecular weight of component (A) is preferably 1,000,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less.

[0033] From the viewpoint of ease of removal, the content of component (A) is preferably 30 parts by mass or more, and more preferably 40 parts by mass or more, per 100 parts by mass of the artificial nail composition.

[0034] Furthermore, from the viewpoint of adhesion and durability, the content of component (A) is 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less, per 100 parts by mass of the artificial nail composition.

[0035] [Component (B): An acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in its molecule]

[0036] The acidic phosphorus compound is not particularly limited as long as it has at least one radically polymerizable unsaturated double bond in its molecule.

[0037] Functional groups having a radically polymerizable unsaturated double bond include (meth)acryloyl group, allyl group, vinyl group, cyanoacryloyl group, propenyl group, and butenyl group, but (meth)acryloyl group and vinyl group are particularly preferred.

[0038] Furthermore, the acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule is a compound having a P-OH bond, which is a compound having at least one selected from a phosphate monoester group, a phosphate diester group, a phosphonic acid group, a phosphonic acid monoester group, a phosphinoate group, and a pyrophosphate group, but compounds having a phosphate monoester group, a phosphate diester group, or a phosphonic acid group are particularly preferred.

[0039] As an example of an acidic phosphorus compound, radical polymerizable phosphate ester compounds having a (meth)acrylate group can be used. Also, as acidic phosphorus compounds, for example, are 2-acryloyloxyethyl phosphate, 2-acryloyloxypropyl phosphate, 2-acryloyloxybutyl phosphate, 2-acryloyloxypentyl phosphate, 2-acryloyloxyhexyl phosphate, acryloyloxyethyl valerate phosphate, acryloyloxypropyl valerate phosphate, acryloyloxybutyl valerate phosphate, acryloyloxypentyl valerate phosphate, acryloyloxyhexyl valerate phosphate, acryloyloxyethyl caproate phosphate, acryloyloxypropyl caproate phosphate, acryloyloxybutyl caproate phosphate, acryloyloxypentyl caproate phosphate, acryloyloxyethyl caprylate phosphate, and caprylic phosphate. One or more substances selected from the group consisting of acryloyloxypropyl caprate, acryloyloxybutyl caprylate phosphate, acryloyloxypentyl caprylate phosphate, acryloyloxyhexyl caprylate phosphate, bis(2-acryloyloxyethyl) phosphate, bis(2-acryloyloxypropyl) phosphate, bis(2-acryloyloxybutyl) phosphate, bis(2-acryloyloxypentyl) phosphate, bis(2-acryloyloxyhexyl) phosphate, acid phosphooxypolyoxyethylene glycol monoacrylate, acid phosphooxypolyoxypropylene glycol monoacrylate, ethylene oxide-modified diacrylate phosphate, propylene oxide-modified diacrylate phosphate, phosphate-modified epoxy acrylate, etc.

[0040] According to this embodiment, by using component (B) and component (C), which will be described later, in combination, high toughness is obtained when the artificial nail composition is cured. As a result, appropriate tackiness can be ensured from curing until swelling with an organic solvent, and consequently, long-term durability is obtained.

[0041] The content of component (B) is not particularly limited, but the lower limit of the content of component (B) is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and particularly preferably 4 parts by mass or more, per 100 parts by mass of the artificial nail composition. The upper limit of the content of component (B) is preferably 40 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 8 parts by mass or less, per 100 parts by mass of the artificial nail composition.

[0042] The amount of phosphoric acid contained in component (B) is preferably less than 7 parts by mass, 6 parts by mass or less, 5 parts by mass or less, and more preferably 3 parts by mass or less, per 100 parts by mass of component (B). In this embodiment, the amount of phosphoric acid is expressed as a mass ratio calculated from the ratio of the molecular weight of the phosphoric acid molecules contained in component (B) to the molecular weight of component (B).

[0043] The phosphoric acid content is less than 7 parts by mass, which makes it possible to set the content of component (B) to 4.5 parts by mass or more per 100 parts by mass of the composition, thereby ensuring higher adhesion. Furthermore, because the amount of phosphoric acid contained in component (B) is less than 7 parts by mass per 100 parts by mass of component (B), clouding over time can be suppressed even if the content of component (B) is 4.5 parts by mass or more per 100 parts by mass of the composition.

[0044] Furthermore, while there is no particular lower limit to the amount of phosphoric acid, from the viewpoint of ensuring good adhesion between natural nails and artificial nails, it is preferable that it be 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of component (B).

[0045] According to the invention described in this embodiment, it is possible to provide an artificial nail composition that ensures the same level of adhesion and durability as when a conventional component used as the main component of an artificial nail composition (for example, a polyfunctional urethane (meth)acrylate oligomer without a (meth)acrylamide group) is used as an essential component, while also ensuring the ease of removal, which is an advantage of using polyurethane having a (meth)acrylamide group as an essential component. At the same time, it is possible to achieve high aesthetic appeal by suppressing discoloration over time.

[0046] [(C) Component: (meth)acrylic acid ester monomer] (C) The type of component is not particularly limited. Examples of monofunctional monomers include alkyl(meth)acrylates such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, amyl(meth)acrylate, hexyl(meth)acrylate, and heptyl(meth)acrylate; (meth)acrylates of alkylene oxide adducts of alkylphenols; cyclohexyl(meth)acrylate; and benzyl(meth)acrylate.

[0047] Examples also include (meth)acrylic vinyl monomers having hydroxyl groups, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate.

[0048] Examples of monomers with two or more functionalities include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and butylene glycol di(meth)acrylate.

[0049] Examples of (meth)acrylates of polyol alkylene oxides include tetramethylolmethane tetra(meth)acrylate, trimethylolethane tri(meth)acrylate, ditrimethylolethane tritetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, diglycerin tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0050] Other examples include di(meth)acrylates of alkylene oxide modified bisphenols such as bisphenol A, F, and S; di(meth)acrylates of hydrogenated bisphenols such as bisphenol A, F, and S; di(meth)acrylates of alkylene oxide modified hydrogenated bisphenols such as bisphenol A, F, and S; and di(meth)acrylates of alkylene oxide modified trisphenols.

[0051] Furthermore, isobornyl (meth)acrylates, in which a (meth)acrylic group is bonded to an isobornyl group (isobornol with one OH group removed), are also given as examples.

[0052] Other examples include polyfunctional monomers such as polylactone di(meth)acrylates of alkylene glycols like polyethylene glycol and polypropylene glycol, and polylactone (meth)acrylates of glycerin, diglycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol.

[0053] In this embodiment, (meth)acrylate is a general term for acrylate and methacrylate, and includes both acryloyl group-containing polymerizable monomers and methacryloyl group-containing polymerizable monomers.

[0054] Component (C) may be a mixture of two or more types, rather than just one type. Furthermore, since higher toughness can be obtained by using component (B) and component (C) in combination, it is preferable that component (C) is a compound that does not contain phosphorus atoms.

[0055] As mentioned above, component (C) may also include (meth)acrylic vinyl monomers having hydroxyl groups, i.e., hydrophilic compounds. However, the proportion of hydrophilic compounds in component (C) is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and particularly preferably 20 parts by mass or less, per 100 parts by mass of the artificial nail composition. Although hydrophilic compounds are expected to have some effect in suppressing the whitening of the cured product over time, a high proportion of hydrophilic compounds may affect the strength of the cured product. Furthermore, a high proportion of hydrophilic compounds may cause problems due to the absorption of moisture from the natural nail.

[0056] (C) Since the proportion of hydrophilic compounds in component (C) is 35 parts by mass or less per 100 parts by mass of the artificial nail composition, it is possible to provide an artificial nail composition that achieves both good adhesion between natural nails and artificial nails and high aesthetic appeal by suppressing discoloration over time, as well as solving issues such as high strength of the cured product and prevention of problems caused by moisture absorption from natural nails.

[0057] The content of component (C) is not particularly limited, but the lower limit of the content of component (C) is preferably 0.5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 40 parts by mass or more, per 100 parts by mass of the artificial nail composition. The upper limit of the content of component (C) is preferably 90 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the artificial nail composition.

[0058] [Component (D): Radical polymerization initiator] The artificial nail composition described in this embodiment contains a radical polymerization initiator. The use of cationic polymerization initiators is undesirable because it may cause toxicity problems.

[0059] The radical polymerization initiator may be photocurable or thermocurable, but it is preferable that the radical polymerization initiator be photocurable, as it allows the artificial nail composition to harden in tens of seconds to a few minutes.

[0060] [Photoradical polymerization initiator] If the artificial nail composition is photocurable, component (D) is not particularly limited as long as it has the ability to initiate radical copolymerization by the action of light.For example, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-phenyl-1-phenylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl Acetophenone initiators such as ylketone and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1; benzoin initiators such as benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyl methyl ketal; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylic benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3'-dimethyl-4-methoxyb Benzophenone initiators such as benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone initiators such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, and 2,4-dichlorothioxanthone. Initiators include ketone-based initiators such as α-acyloxime esters, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, dibenzosverone, 2-ethylanthraquinone, and 4',4''-diethylisophthalophenone; imidazole-based initiators such as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-imidazole; acylphosphine oxide-based initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and carbazole-based initiators.

[0061] Photoradical polymerization initiators may be used alone or in combination of two or more types.

[0062] The content of the photoradical polymerization initiator is not particularly limited, but it is preferably 0.01 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the artificial nail composition, and more preferably 0.1 parts by mass or more and 10 parts by mass or less.

[0063] [Thermal radical polymerization initiator] If the artificial nail composition is thermosetting, it is preferable that component (D) is thermosetting at room temperature.

[0064] As a thermosetting thermal radical polymerization initiator at room temperature, either an organic peroxide or an azo compound may be used. Specific examples of organic peroxides include methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetate peroxide, acetyl acetate peroxide, 1,1-bis(t-butyl peroxy)butane, 1,1-bis(t-butyl peroxy)-cyclohexane, 1,1-bis(t-butyl peroxy)-2-methylcyclohexane, 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane, and 1,1-bis(t-butyl peroxy) Oxy)cyclododecane, 1,1-bis(t-hexylperoxy)-cyclohexane, 1,1-bis(t-hexylperoxy)-3,3.5-trimethylcyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, t-butyl hydroperoxide, t-hexyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide Di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, isobutyryl peroxide, 3,3,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinate peroxide D, m-Toloyl benzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-s-butyl peroxydicarbonate, di(3-methyl-3-methoxybutyl) peroxydicarbonate, α,α'-Bis(neodecanoylperoxy)diisopropylbenzene, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, cumylperoxyneodecanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxy- 2-Ethylhexanoate, t-Hexylperoxy-2-ethylhexanoate, 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, 2,5-Dimethyl-2,5-Bis(2-ethylhexanoylperoxy)hexanoate, 1-Cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-Butylperoxy-3,5,5-Trimethylhexanoate, t-Butylperoxyiso Examples include propyl monocarbonate, t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxyallyl monocarbonate, t-butyl peroxyisobutyrate, t-butyl peroxymalate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, t-butyl peroxy-m-tolylbenzoate, t-butyl peroxylaurate, t-butyl peroxyacetate, bis(t-butyl peroxy)isophthalate, 2,5-dimethyl-2,5-bis(m-tolyl peroxy)hexane, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, t-butyl trimethylsilyl peroxide, 3,3',4,4'-tetra(t-butyl peroxycarbonyl)benzophenone, and 2,3-dimethyl-2,3-diphenylbutane.

[0065] Specific examples of azo compounds include 1-[(1-cyano-1-methylethyl)azo]formamide, 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis(2-methylpropionamidine)dihydrochloride, and 2,2-azo Bis(2-methyl-N-phenylpropionamidine)dihydrochloride, 2,2'-azobis[N-(4-chlorophenyl)-2-methylpropionamidine]dihydrochloride, 2,2'-azobis[N-(4-hydrophenyl)-2-methylpropionamidine]dihydrochloride, 2,2'-azobis[2-methyl-N-(2-propenyl)propionamidine]dihydrochloride, 2,2'-azobis[N-(2-hydroxyethyl)-2-methylpropionamidine]dihydrochloride, 2,2'-azobis[2-methyl-N-(phenyl [Methyl)propionamidine]dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}dihydrochloride, 2,2'-azobis[2-(4,5,6,7-tetrahydro-1H-1,3-diazepine-2-yl)propane] Pan]dihydrochloride, 2,2'-azobis[2-(3,4,5,6-tetrahydropyrimidine-2-yl)propane]dihydrochloride, 2,2'-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidine-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,Examples include 2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide}, 2,2'-azobis(2-methylpropane), 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2-azobis(2-methylpropionate), 4,4'-azobis(4-cyanopentanoic acid), and 2,2'-azobis[2-(hydroxymethyl)propionitrile].

[0066] Thermal radical polymerization initiators may be used alone or in combination of two or more types.

[0067] The content of the thermal radical polymerization initiator is not particularly limited, but it is preferably 0.01 parts by mass or more and 10 parts by mass or less, and more preferably 0.1 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the artificial nail composition.

[0068] Furthermore, component (D) may contain both a thermal radical polymerization initiator and a photoradical polymerization initiator.

[0069] [Other ingredients] The artificial nail composition contains components (A) to (C). However, in addition to components (A) to (C), the artificial nail composition may also contain other polymerizable compounds, such as monomeric oligomers or polymers having at least one polymerizable group in the molecule. Furthermore, substituents such as acidic groups or fluoro groups may be present within the same molecule.

[0070] Examples of oligomers having multiple (meth)acryloyl groups in their molecule include (meth)acrylate oligomers, which have a molecular chain structure formed by the polymerization of multiple monomers and multiple (meth)acryloyl groups in their molecule. The weight-average molecular weight of (meth)acrylate oligomers is usually between 400 and 50,000.

[0071] Examples of (meth)acrylate oligomers include epoxy (meth)acrylate oligomers having molecular chains formed by the ring-opening reaction of epoxides, polyester (meth)acrylate oligomers having multiple ester bonds in their molecular chains, and polyether (meth)acrylate oligomers having multiple ether bonds in their molecular chains.

[0072] [Various additives] The artificial nail composition of this embodiment may contain various known additives as needed. Examples of such additives include polymerization accelerators, polymerization inhibitors, colorants, discoloration inhibitors, fluorescent agents, ultraviolet absorbers, antibacterial agents, and volatile organic solvents. [Examples]

[0073] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. There isn't one.

[0074] <Artificial nail composition> [Ingredients used] (A) A urethane (meth)acrylate oligomer or polymer having multiple urethane bonds in its molecular chain and having (meth)acrylamide groups at at least both ends of the molecular chain. A1: Quick Cure® 8100 (manufactured by KJ Chemicals) A2:Quick Cure (registered trademark) 7100 (manufactured by KJ Chemicals) A3: Quick Cure® 7300 (manufactured by KJ Chemicals)

[0075] (UA) Urethane (meth)acrylate oligomer or polymer having multiple urethane bonds in the molecular chain and (meth)acrylate groups at at least both ends of the molecular chain. UA1: BisHEA(poly(1,4-butanediol)-9 / IPDI) copolymer (weight-average molecular weight: 6500) UA2: BisHEA(poly(1,4-butanediol)-9 / IPDI) copolymer (weight-average molecular weight: 4500) HEA is hydroxyethyl acrylate, and IPDI is 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (common name: isophorone diisocyanate).

[0076] (B) Acidic phosphorus compounds having at least one radical polymerizable unsaturated double bond in the molecule B1: Bis(2-methacryloxyethyl)-phosphate B2: Mixture of 2-acryloxyethyl phosphate and bis(2-acryloxyethyl)-phosphate B3: Hydroxybutyl (meth)acrylate acid phosphate

[0077] (C)(meth)acrylic acid ester monomer C1: Isobornyl methacrylate C2: 2-hydroxyethyl methacrylate C3: Hydroxypropyl methacrylate C4: Acryloylmorpholin

[0078] (D) Radical polymerization initiator D1: 2,4,6-trimethylbenzoyldiphenylphosphine oxide

[0079] [Preparation of artificial nail composition] According to the preparation and mixing methods shown in Tables 1 and 2, the components A1-A3, UA1-UA2, B1-B3, C1-C4, and D1 were weighed using an electronic balance and then stirred and mixed to prepare the artificial nail compositions for Examples 1-10 and Comparative Examples 1-7.

[0080] [Table 1]

[0081] [Table 2]

[0082] <Adhesion Test> In the adhesion test, the artificial nail composition was applied to the subject's natural nail, cured, and then its adhesion was evaluated after a certain period of daily life. The detailed procedure for the adhesion test is shown below.

[0083] [Preparation of samples for adhesion testing] 1) Use a gel nail file (nail file, grit: 600) to file the surface of the natural nail to obtain a fresh surface. 2) Next, wipe the fresh surface with a wipe impregnated with ethanol to remove dust and oil. 3) Next, apply the artificial nail composition to a clean surface from which dust and other debris have been removed, and cure it using a commercially available LED light specifically for gel nails. 4) Next, apply a commercially available color gel (red shade) over the cured artificial nail composition and cure it using a commercially available LED light specifically for gel nails. 5) Next, apply a commercially available top gel over the cured commercially available color gel and cure it using a commercially available LED light specifically for gel nails. Note that top gel is a gel nail product applied to the surface of cosmetic products using gel nails, such as artificial nail compositions applied to natural nails, to obtain a good shine.

[0084] [Evaluation and evaluation scale of adhesion in adhesion testing] The subjects went about their daily lives for 14 days with the cosmetic product applied to their natural nails. After 14 days of daily life, the state of the hardened artificial nail composition on the natural nails was classified according to the scale in Table 3, and this was used as the evaluation score for the adhesion test. The results are shown in Tables 5 and 6. [Table 3]

[0085] <Evaluation of gel nail removal ease, Part 1> For gel nails on natural nails, use a gel nail file (nail file, grit: 80) to file away a portion of the top gel and the color gel in the middle layer.

[0086] The top gel and color gel surface layers are scraped off, and a wipe impregnated with the artificial nail removal composition of the example or comparative example is placed on the exposed color gel layer of the gel nail, and the fingertip is wrapped in aluminum foil. This prevents the evaporation of the organic solvent in the artificial nail removal composition, causing the hardened gel nail to swell due to the organic solvent. After leaving the fingertip undisturbed for 10 minutes, the aluminum foil and wipe are removed.

[0087] We attempted to remove the hardened gel nail from natural nails after removing the aluminum foil and wipes, and observed the process. The results of this observation were classified according to the scale in Table 4 and used as the evaluation score (removability) for the removeability test. The results are shown in Tables 5 and 6. [Table 4]

[0088] In this case, if the removeability scale is marked "×", it is deemed inappropriate because it requires strong pressure with a spatula or metal pusher, which may damage the nail of the person wearing the gel nail, and also requires time to remove the hardened gel nail. On the other hand, the removeability scale scores of "○", "◎", and "◎◎" indicate that the removal can be done safely and quickly without the need to press hard with a spatula or metal pusher, and are therefore considered appropriate.

[0089] <Evaluation of Gel Nail Removability, Part 2> Calculation of Cohesive Breakdown Rate of the Nail Surface To determine the impact of the removal procedure on the nail, one can observe the nail adhesion surface of the removed piece. In gel nail removal, the ideal removal state is when the gel nail separates at the adhesive interface between the gel nail and the nail, resulting in minimal impact on the nail. However, if interfacial separation occurs, the adhesive durability of the gel nail is often insufficient, and even in an ideal removal state, it cannot be said that the gel nail material is ideal.

[0090] On the other hand, the removal process observed in many gel nails with good adhesive durability is cohesive fracture of the natural nail. Although the surface of the nail is a tough tissue made up of layers of keratin, its surface is a brittle state due to discontinuous keratin layer structure caused by dryness and external stimuli, and cohesive fracture of the nail surface is observed during the removal process. In other words, even if a gel nail material has ideal adhesive durability, it cannot be said to have an ideal removal process. To achieve both such adhesive durability and removal performance that does not burden the nail, it is desirable that the material be removed by cohesive fracture of the gel nail.

[0091] The artificial nail fragments (referred to as "removed fragments"), which have been swollen with acetone or the like and removed from the nail surface, are observed using an optical microscope to check for the presence or absence of the stratum corneum on the nail surface. As shown in Figure 1, in the actual removal procedure, interfacial separation between the gel and the nail, cohesive failure of the nail surface, and cohesive failure of the gel material appear together, with cohesive failure of the nail surface being the main problem. Therefore, the ratio of the area of ​​the cohesive failure portion of the natural nail to the entire observation surface (referred to as the "cohesive failure rate of the nail surface") is calculated, and it is desirable that this cohesive failure rate of the nail surface be 40% or less.

[0092] [How to determine the cohesive failure rate of the nail surface] 1) Take a 100x image of the back side of the removed piece (the side that was in contact with the nail surface) using an optical microscope. 2) In this study, a red-colored gel was used, so the nail tissue attached to the gel fragments due to cohesive breakdown was observed to appear white. 3) As shown in Figure 2, the central part of the obtained microscope image is divided into 28 sections. 4) Check the adhesive failure status within each frame. If any cohesive failure of the nail surface is observed within the frame, one point will be awarded. 5) Assign the aforementioned points to all slots (28 slots) and calculate the total score. 6) The cohesive failure rate of the nail surface is calculated using the following formula.

number

[0093] As described above, the rate of cohesive failure of the nail surface was calculated, and if the value is 40% or less, it can be said that the removal operation involved a mixture of interfacial separation between the gel and the nail or cohesive failure of the gel material, with only slight cohesive failure of the natural nail that damages the nail surface, thus indicating ideal removal performance. The results are shown in Tables 5 and 6.

[0094] <Result> [Table 5] [Table 6]

[0095] The artificial nail compositions in the examples all ensured high adhesion and durability, while also possessing the advantage of easy removal, which is a benefit of using polyurethane having (meth)acrylamide groups as an essential component. In particular, when the content of component (B) was 4 parts by mass or more per 100 parts by mass of the artificial nail composition, the balance of adhesion, durability, and easy removal was best (Examples 3, 4, 6, and 7).

[0096] In contrast, Comparative Examples 1-5 showed high aggregation breakdown rates and insufficient removal performance. This is thought to be due to the fact that component (A) did not have (meth)acrylamide groups at at least both ends of its molecular chain.

[0097] Furthermore, even if component (A) has (meth)acrylamide groups at at least both ends of its molecular chain, if the composition does not contain component (B), sufficient adhesion cannot be obtained in the first place (Comparative Examples 6 and 7).

Claims

1. (A) A urethane (meth)acrylate oligomer or polymer having multiple urethane bonds in its molecular chain and having (meth)acrylamide groups at at least both ends of the molecular chain, (B) An acidic phosphorus compound having at least one radical polymerizable unsaturated double bond in the molecule, (C) (meth)acrylic acid ester monomer and (D) An artificial nail composition containing a radical polymerization initiator.

2. The proportion of component (A) is 30 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the artificial nail composition, according to claim 1.

3. The artificial nail composition according to claim 1 or 2, wherein the amount of phosphoric acid contained in component (B) is 0.01 parts by mass or more and less than 7 parts by mass per 100 parts by mass of component (B).

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