Artificial claw components

Abstract

To provide an artificial nail composition that ensures high removability by using polyurethane having a (meth)acrylamide group as an essential component, while also achieving the performance originally required of an artificial nail composition, namely, good adhesion between natural nails and artificial nails and durability from curing to swelling in an organic solvent. [Solution] The artificial nail composition contains (A) a urethane (meth)acrylate oligomer or polymer having multiple urethane bonds in the molecular chain and (meth)acrylamide groups at least at 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 artificial nail compositions. [Background technology]

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

[0003] The properties required for an artificial nail composition include adhesion between the natural nail and the artificial nail, surface smoothness and gloss, and film durability, and for example, an artificial nail composition has been proposed that contains (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) a radical polymerization initiator (see Patent Document 1).The compound described in Patent Document 1 can provide an artificial nail composition that satisfies these properties.

[0004] However, when an artificial nail composition is formed on a natural nail, it must be removed after a certain period of time. To remove the artificial nail composition, the surface of the artificial nail composition is scratched by sanding with a coarse nail file, a wipe soaked in an organic solvent such as acetone is applied to the artificial nail composition, and the wipe is left wrapped in aluminum foil or the like to swell the artificial nail composition. The swollen artificial nail composition is then peeled off using a stick-shaped tool or the like. If the skill of removing the artificial nail composition is poor, there is a concern that the artificial nail composition may be scraped off more than necessary, resulting in the scraping off of part of the natural nail as well. Therefore, there is a need for an artificial nail composition that removes only the artificial nail composition without scraping off the natural nail.

[0005] It has been proposed to use polyurethane having a (meth)acrylamide group as an essential component, as it combines flexibility and toughness and can be easily repaired and removed (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7104392 [Patent Document 2] Japanese Patent Application Publication No. 2019-085394 Summary of the Invention [Problem to be solved by the invention]

[0007] Indeed, when polyurethane having (meth)acrylamide groups is used as an essential component, removability is improved. This is thought to be due to the brittleness that occurs when the artificial nail composition is swelled in an organic solvent such as acetone. However, simply using polyurethane having (meth)acrylamide groups as an essential component can result in inferior durability between the curing of the artificial nail composition and swelling in an organic solvent, compared to when a component that has traditionally been used as the main component of an artificial nail composition (e.g., a polyfunctional urethane (meth)acrylate oligomer not having a (meth)acrylamide group) is used as the essential component. Therefore, there is a need to provide an artificial nail composition that ensures good adhesion between the natural nail and the artificial nail and high removability, while also being durable between the curing and swelling in an organic solvent.

[0008] An object of the present invention is to provide an artificial nail composition that ensures high removability by using a polyurethane having a (meth)acrylamide group as an essential component, while also achieving the performance originally required of an artificial nail composition, i.e., good adhesion between the natural nail and the artificial nail and durability from curing to swelling in an organic solvent. [Means for solving the problem]

[0009] As a result of extensive research aimed at solving the above problems, the present inventors have found that the above object can be achieved by using a specific acidic phosphorus compound and a (meth)acrylic acid ester monomer as components to be used in combination with a polyurethane having a (meth)acrylamide group, and have thus completed the present invention. Specifically, the present invention provides the following.

[0010] A first aspect of the invention provides an artificial nail composition containing: (A) a urethane (meth)acrylate oligomer or polymer having a plurality of urethane bonds in the molecular chain and having (meth)acrylamide groups at least at 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 the molecular chain. Therefore, when a wipe soaked in an organic solvent is applied to the artificial nail composition, it swells well and becomes brittle. Therefore, when the artificial nail composition is peeled off using a stick-shaped tool or the like, the artificial nail composition can be easily peeled off with little force. Therefore, the artificial nail composition can be removed without scraping the natural nail or putting a strain on the natural nail.

[0012] The artificial nail composition also uses a specific acidic phosphorus compound as component (B) in combination with a (meth)acrylic acid ester monomer as component (C). The combined use of components (B) and (C) provides high toughness when the artificial nail composition is cured, ensuring appropriate adhesion from the time of curing until swelling with an organic solvent, resulting in long-term durability.

[0013] As a result, according to the first aspect of the invention, it is possible to provide an artificial nail composition that ensures high removability while also achieving the performance originally required of an artificial nail composition, i.e., good adhesion between the natural nail and the artificial nail and durability from curing to swelling in an organic solvent.

[0014] The second feature of the invention is the first feature of the invention, and provides an artificial nail composition in which 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 second feature of the invention, it is possible to further improve removability without impairing adhesiveness or durability.

[0016] The third aspect of the invention is the first or second aspect of the invention, and provides an artificial nail composition in which 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 the natural nail and the artificial nail, it can sometimes become cloudy over time. According to the third aspect of the invention, the amount of phosphoric acid contained in component (B) is less than 7 parts by mass, which prevents clouding over time and allows the composition to combine aesthetic appeal in addition to adhesion, durability, and removability. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an artificial nail composition that ensures the same adhesiveness and durability as when an artificial nail composition contains, as an essential component, a component that has traditionally been used as a main component in artificial nail compositions (for example, a polyfunctional urethane (meth)acrylate oligomer that does not have a (meth)acrylamide group), while also ensuring the removability that is an advantage of using a polyurethane that has a (meth)acrylamide group as an essential component. [Brief explanation of the drawings]

[0019] [Figure 1] Figure 1 shows the various phenomena that occur when removing gel nails: interfacial peeling between the gel and the nail, cohesive failure on the nail surface, and cohesive failure of the gel material. [Figure 2] FIG. 2 is a diagram for explaining a method for determining the cohesive failure rate of the nail surface. DETAILED DESCRIPTION OF THE INVENTION

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

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

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

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

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

[0025] Polycarbonate and polyolefin skeletons can be obtained by reacting a polyol having the respective skeleton with a polyisocyanate and a compound having a (meth)acrylamide group. Examples of polyols include polyolefin polyols such as 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, and hydrogenated polyisoprene polyol; and polycarbonate polyols composed of a polyol having a carbon number of 1 to 12, linear, branched, or cyclic aliphatic hydrocarbon or heterocyclic skeleton, and a carbonate diester.

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

[0027] In addition, one or more of polyols having a linear, branched, or cyclic aliphatic hydrocarbon or heterocyclic skeleton having 1 to 12 carbon atoms, polyether polyols, polyester polyols, polyols having a hydroxyl group introduced into a silicone skeleton, and polyols obtained by copolymerizing a hydroxyl group-containing (meth)acrylate 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, and specific examples thereof include 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, and 2,2,4-trimethylhexamethylene diisocyanate; 1,3-phenylene diisocyanate; 1,4-phenylene diisocyanate; Examples of the isocyanate 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; and multimers such as adduct types, isocyanurate types, and biuret types of these isocyanates.

[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-normal-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. Of these, hydroxyethylacrylamide is preferred from the viewpoint of safety and ease of procurement.

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

[0031] Furthermore, the number of (meth)acrylamide groups (number of functional groups) contained 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 natural nails to form gel nails, preventing excessive generation of polymerization heat.

[0032] Component (A) may be an oligomer or a polymer, but is preferably an oligomer to prevent the viscosity of the uncured product from becoming too high and resulting in insufficient coatability. Generally, the weight-average molecular weight of an oligomer is typically 400 or more and 50,000 or less, and the weight-average molecular weight of a polymer is typically greater than 50,000. From the viewpoint of removability, 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. Furthermore, from the viewpoint of coatability, 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 removability, 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 adhesiveness and durability, the content of component (A) is preferably 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 the molecule]

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

[0037] Examples of functional groups having a radically polymerizable unsaturated double bond include (meth)acryloyl groups, allyl groups, vinyl groups, cyanoacryloyl groups, propenyl groups, and butenyl groups, with (meth)acryloyl groups and vinyl groups being particularly preferred.

[0038] Furthermore, the acidic phosphorus compound having at least one radically polymerizable unsaturated double bond in the molecule and having a P-OH bond is a compound having at least one selected from a phosphoric acid monoester group, a phosphoric acid diester group, a phosphonic acid group, a phosphonic acid monoester group, a phosphorous acid monoester group, a phosphinic acid group, and a pyrophosphate group, with compounds having a phosphoric acid monoester group, a phosphoric acid diester group, or a phosphonic acid group being particularly preferred.

[0039] Examples of the acidic phosphorus compound include radical polymerizable phosphate ester compounds having a (meth)acrylate group. Examples of the acidic phosphorus compound include 2-acryloyloxyethyl phosphate, 2-acryloyloxypropyl phosphate, 2-acryloyloxybutyl phosphate, 2-acryloyloxypentyl phosphate, 2-acryloyloxyhexyl phosphate, acryloyloxyethyl valerate phosphate, acryloyloxypropyl valerate, acryloyloxybutyl valerate phosphate, acryloyloxypentyl valerate, acryloyloxyhexyl valerate, acryloyloxyethyl caproate phosphate, acryloyloxypropyl caproate phosphate, acryloyloxybutyl caproate phosphate, acryloyloxypentyl caproate, acryloyloxyhexyl caproate phosphate, acryloyloxyethyl caprylate phosphate, and caprylic acid phosphate. and acryloyloxypropyl phosphate, acryloyloxybutyl caprylate, acryloyloxypentyl caprylate, acryloyloxyhexyl caprylate, bis(2-acryloyloxyethyl)phosphate, bis(2-acryloyloxypropyl)phosphate, bis(2-acryloyloxybutyl)phosphate, bis(2-acryloyloxypentyl)phosphate, bis(2-acryloyloxyhexyl)phosphate, acid phosphooxy polyoxyethylene glycol monoacrylate, acid phosphooxy polyoxypropylene glycol monoacrylate, ethylene oxide-modified phosphate diacrylate, propylene oxide-modified phosphate diacrylate, and phosphate-modified epoxy acrylate.

[0040] According to this embodiment, the artificial nail composition is cured using the (B) component in combination with the (C) component, which will be described later. This results in high toughness, and as a result, appropriate adhesion can be maintained from the time of curing until swelling with an organic solvent, resulting in long-term durability.

[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 less than 7 parts by mass, preferably 6 parts by mass or less, more preferably 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 a value expressed as a mass ratio calculated from the ratio of the molecular weight of the phosphoric acid molecule contained in component (B) to the molecular weight of component (B).

[0043] By keeping the amount of phosphoric acid below 7 parts by mass, it is possible to increase the amount of component (B) to 4.5 parts by mass or more per 100 parts by mass of the composition, ensuring higher adhesiveness. 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 amount of component (B) is 4.5 parts by mass or more per 100 parts by mass of the composition.

[0044] Furthermore, there is no particular lower limit to the amount of phosphoric acid, but from the viewpoint of ensuring good adhesion between the natural nail and the artificial nail, it is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and even more preferably 0.5 part 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 adhesiveness and durability as artificial nail compositions that contain a component that has traditionally been used as the main component (for example, a polyfunctional urethane (meth)acrylate oligomer that does not contain a (meth)acrylamide group) as the essential component, while also ensuring the removability that is an advantage of using a polyurethane that contains a (meth)acrylamide group as the essential component. In this case, it is also possible to achieve high aesthetics by suppressing clouding over time.

[0046] [Component (C): (Meth)acrylic acid ester monomer] The type of component (C) 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] Other examples include (meth)acrylic vinyl monomers having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate.

[0048] Examples of the difunctional or higher functional monomer 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 the (meth)acrylate of a polyol alkylene oxide 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] Another example is isobornyl(meth)acrylate, in which a (meth)acrylic group and an isobornyl group (one OH group removed from isobornyl) are bonded together.

[0052] Other examples include polyfunctional monomers such as polylactonate di(meth)acrylates of alkylene glycols such as polyethylene glycol and polypropylene glycol, and polylactonate (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, or may be a single type. Furthermore, since higher toughness can be obtained by using components (B) and (C) in combination, component (C) is preferably a compound that does not contain a phosphorus atom.

[0055] As mentioned above, component (C) may also contain a (meth)acrylic vinyl monomer having a hydroxyl group, i.e., a hydrophilic compound. However, the proportion of the hydrophilic compound in component (C) is preferably 35 parts by weight or less, more preferably 30 parts by weight or less, even more preferably 25 parts by weight or less, and particularly preferably 20 parts by weight or less, per 100 parts by weight of the artificial nail composition. While the hydrophilic compound is expected to have a certain effect in preventing the cured product from becoming cloudy over time, a high proportion of hydrophilic compound may affect the strength of the cured product. Furthermore, a high proportion of hydrophilic compound may cause problems due to moisture absorption from natural nails.

[0056] Since the ratio of the hydrophilic compound in component (C) is 35 parts by mass or less per 100 parts by mass of the artificial nail composition, an artificial nail composition can be provided that not only achieves good adhesion between the natural nail and the artificial nail and high aesthetic appeal by preventing clouding over time, but also solves issues such as high strength of the cured product and prevention of problems caused by moisture absorption from the natural nail.

[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 according to the present embodiment contains a radical polymerization initiator. The use of a cationic polymerization initiator is not preferred because it may cause toxicity problems.

[0059] The radical polymerization initiator may be photocurable or thermosetting, but it is preferable that the radical polymerization initiator be photocurable because the artificial nail composition can be hardened in a few tens of seconds to a few minutes.

[0060] [Photoradical polymerization initiator] When 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-based initiators such as benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzil methyl ketal; benzoin-based initiators such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3'-dimethyl-4-methoxybenzyl benzoate. benzophenone-based initiators such as benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone-based 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 initiators such as α-acyloxime ester, methylphenyl glyoxylate, benzil, 9,10-phenanthrenequinone, camphorquinone, dibenzosuberone, 2-ethylanthraquinone, and 4',4''-diethylisophthalophenone; imidazole initiators such as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-imidazole; acylphosphine oxide initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and carbazole initiators.

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

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

[0063] [Thermal radical polymerization initiator] When the artificial nail composition is thermosetting, component (D) preferably has room temperature thermosetting properties.

[0064] As the thermal radical polymerization initiator having room temperature thermosetting properties, 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-butylperoxy)butane, 1,1-bis(t-butylperoxy)-cyclohexane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-4,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-5,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-6,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-7,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-8,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-9,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-1,1-bis(t-butylperoxy)-2 ...3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-1,1-bis(t-butylperoxy)-2,4,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-1,1- 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 Benzene, 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)hexyne-3, isobutyryl peroxide, 3,3,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic acid peroxide , m-toluoylbenzoyl 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-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, cumyl peroxyneodecanoate, t-butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxy- 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 of the peroxypropanol include propyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-butylperoxyallyl monocarbonate, t-butylperoxyisobutyrate, t-butylperoxymalate, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxy-m-toluylbenzoate, t-butylperoxylaurate, t-butylperoxyacetate, bis(t-butylperoxy)isophthalate, 2,5-dimethyl-2,5-bis(m-toluylperoxy)hexane, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butyltrimethylsilyl peroxide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)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-carbonitrile), 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, 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 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-diazepin-2-yl)propane}dihydrochloride pan] dihydrochloride, 2,2'-azobis[2-(3,4,5,6-tetrahydropyrimidin-2-yl)propane] dihydrochloride, 2,2'-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidin-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] The thermal radical polymerization initiators may be used alone or in combination of two or more.

[0067] The content of the thermal radical polymerization initiator is not particularly limited, but 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] The 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 oligomers or polymers of monomers having at least one polymerizable group in the molecule. Furthermore, the artificial nail composition may also contain a substituent such as an acidic group or a fluoro group in the same molecule.

[0070] Examples of oligomers having multiple (meth)acryloyl groups in the molecule include (meth)acrylate oligomers having multiple (meth)acryloyl groups and a molecular chain structure formed by polymerizing multiple monomers in the molecule. The weight-average molecular weight of the (meth)acrylate oligomer is usually 400 or more and 50,000 or less.

[0071] Examples of the (meth)acrylate oligomer include an epoxy (meth)acrylate oligomer having a molecular chain formed by a ring-opening reaction of an epoxide, a polyester (meth)acrylate oligomer having multiple ester bonds in the molecular chain, and a polyether (meth)acrylate oligomer having multiple ether bonds in the molecular chain.

[0072] [Various additives] The artificial nail composition of the present 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. [Example]

[0073] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. There is no.

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

[0075] (UA) A urethane (meth)acrylate oligomer or polymer having multiple urethane bonds in the molecular chain and (meth)acrylate groups at least at 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) Here, HEA is hydroxyethyl acrylate, and IPDI is 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (common name: isophorone diisocyanate).

[0076] (B) an acidic phosphorus compound having at least one radically 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: Acryloylmorpholine

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

[0079] [Preparation of Artificial Nail Composition] According to the adjusted mixture in Tables 1 and 2, the above components A1 to A3, UA1 to UA2, B1 to B3, C1 to C4, and D1 were weighed using an electronic balance, and then stirred and mixed to prepare artificial nail compositions according to Examples 1 to 10 and Comparative Examples 1 to 7.

[0080] [Table 1]

[0081] [Table 2]

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

[0083] [Preparation of Adhesion Test Samples] 1) Use a nail file for gel nails (nail file, coarseness: 600 grit) to file the natural nail surface to obtain a fresh surface. 2) Next, wipe the fresh surface with an ethanol-soaked wipe to remove dust and oil. 3) Next, apply the artificial nail composition to the fresh surface from which dust and other particles have been removed, and then cure it using a commercially available LED light specifically for gel nails. 4) Next, a commercially available color gel (reddish color) is applied on top of the hardened artificial nail composition and hardened using a commercially available LED light specifically for gel nails. 5) Next, a commercially available top gel is applied on top of the cured commercially available color gel and cured using a commercially available LED light for gel nails. The top gel is a gel nail product that is applied to the surface of the gel nails, such as artificial nail compositions, that have been applied to natural nails to achieve a good shine.

[0084] [Adhesion evaluation and evaluation scale in adhesion tests] The subjects carried out their daily lives for 14 days with the cosmetic applied to their natural nails. The condition of the cured artificial nail composition on the natural nails after 14 days of daily living was then rated on the scale shown in Table 3. The results are shown in Tables 5 and 6. [Table 3]

[0085] <Gel nail removal evaluation part 1> For gel nails on natural nails, use a nail file for gel nails (nail file, coarseness: 80 grit) to scrape off the top gel on the outermost surface and part of the color gel in the middle layer.

[0086] The top gel and color gel surface layers were scraped off, and a wipe impregnated with the artificial nail removal composition of the Example or Comparative Example was placed on the gel nail, exposing the color gel layer. The fingertip was then wrapped in aluminum foil. This prevented the organic solvent in the artificial nail removal composition from evaporating, allowing the organic solvent to swell the cured gel nail. The fingertip was then left to stand for 10 minutes, after which the aluminum foil and wipe were removed.

[0087] After removing the aluminum foil and wipe, the cured gel nail was removed from the natural nail and the process was observed. The results of this observation were classified according to the scale in Table 4 to obtain the evaluation score (removability) of the removability test. The results are shown in Tables 5 and 6. [Table 4]

[0088] Here, if the removability rating is "x", it is deemed inappropriate because it requires strong pressure with a spatula or metal pusher, which may damage the nails of the person wearing the gel nail, and it takes time to remove the hardened gel nail. On the other hand, the removability scale of "○", "◎" and "◎◎" indicates that the product can be removed safely and in a short time without the need to press hard with a spatula or metal pusher, and is therefore judged to be appropriate.

[0089] <Evaluation of gel nail removal Part 2> Calculation of the cohesive failure rate on the nail surface The effect of the removal operation on the nail can be confirmed by observing the nail-adhered surface of the removed piece. When removing a gel nail, if peeling occurs at the adhesive interface between the gel nail and the nail, this is an ideal state of removal, with minimal impact on the nail. However, if interfacial peeling occurs, the adhesion durability of the gel nail is often insufficient, and even if the removal is ideal, it is difficult to say that the gel nail material is ideal.

[0090] On the other hand, the removal state observed in many gel nails with good adhesive durability is the cohesive failure of the natural nail. Although the surface of the nail is a tough tissue made up of stacked stratum corneum layers, the surface has a discontinuous stratum corneum structure due to dryness or external stimuli, making it brittle, and cohesive failure of the nail surface is observed during the removal procedure. In other words, even if a gel nail material has ideal adhesive durability, it is difficult to say that it has ideal removal state. To achieve both such adhesive durability and removal performance that does not place a strain on the nail, it is desirable for the material to be removed by the cohesive failure of the gel nail.

[0091] The artificial nail fragment (referred to as the "removed piece") is swollen with acetone or the like and removed from the nail surface. The adhesive surface of the nail is observed under an optical microscope to confirm whether or not the stratum corneum is attached to the nail surface. As shown in Figure 1, during the actual removal procedure, a mixture of interfacial peeling between the gel and the nail, cohesive failure of the nail surface, and cohesive failure of the gel material is observed, and cohesive failure of the nail surface becomes a problem. Therefore, the ratio of the area of ​​the natural nail that is cohesively failed 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 rate of cohesive failure on the nail surface] 1) A 100x image of the back side of the removed piece (the surface that was attached to the nail surface) is taken using an optical microscope. 2) Because a red-colored gel was used in this study, the nail tissue that adhered to the gel pieces due to cohesive failure was observed to be white. 3) As shown in Figure 2, the center of the obtained microscope image is divided into 28 parts. 4) Check the adhesive failure state within each frame, and if cohesive failure is observed on the nail surface even partially within the frame, give it 1 point. 5) Assign the aforementioned scores to all frames (28 frames) and calculate the total score. 6) Calculate the rate of cohesive failure on the nail surface using the following formula.

number

[0093] If the cohesive failure rate on the nail surface is calculated as described above and the value is 40% or less, this indicates that there is a mixture of interfacial peeling between the gel and nail or cohesive failure of the gel material during the actual removal operation, and there is only a slight cohesive failure of the natural nail, which would damage the nail surface, and this can be said to be ideal removal performance. The results are shown in Tables 5 and 6.

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

[0095] The artificial nail compositions of the examples all had high adhesiveness and durability, while also possessing the removability that is an advantage of using polyurethane having a (meth)acrylamide group as an essential component. Among them, 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 adhesiveness, durability, and removability was the best (Examples 3, 4, 6, and 7).

[0096] In contrast, the cohesive failure rate was high and the removal performance was insufficient in Comparative Examples 1 to 5. This is thought to be due to the fact that component (A) did not have (meth)acrylamide groups at least at both ends of the molecular chain.

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

Claims

1. (A) a urethane (meth)acrylate oligomer or polymer having a plurality of urethane bonds in the molecular chain and having (meth)acrylamide groups at least at 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; (D) a radical polymerization initiator, The proportion of the component (A) is 45.5 parts by mass or more and 70 parts by mass or less per 100 parts by mass of the artificial nail composition, The proportion of the component (C) is 40 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the artificial nail composition, The artificial nail composition of claim 1, wherein the ratio of the hydrophilic compound in the component (C) is 30 parts by mass or less per 100 parts by mass of the artificial nail composition.

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

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