Photocurable composition for nails or artificial nails

Abstract

The purpose of the present invention is to provide a photocurable composition for nails or artificial nails, said photocurable composition being capable of forming a cured product having excellent abrasion resistance and high glossiness. The composition contains the following components (A) to (E), and when component (C) contains component (c-1), component (D) does not contain a monofunctional (meth) acrylate or the content of the monofunctional (meth) acrylate as component (D) is 50 mass% or less relative to the total of component (D): component (A): a urethane-modified (meth) acrylate oligomer; component (B): a (meth) acrylate having a bisphenol skeleton; component (C): one or more (meth) acrylic acid esters selected from the group consisting of component (c-1): (meth) acrylic acid ester having an alicyclic hydrocarbon skeleton and component (c-2): (meth) acrylic acid ester having an isocyanurate skeleton (excluding component (A) and component (B)); component (D): a (meth) acrylic acid ester other than components (A) to (C); component (E): a photoinitiator.

Description

Technical Field

[0001] The present invention relates to a photocurable composition for nails or artificial nails. Background Art

[0002] The so-called gel nail is a nail decoration film with high adhesion to the nail and beautiful glossiness obtained by applying a photocurable composition directly or indirectly to a human nail and curing it by irradiating light. Japanese Patent Publication No. 2017-210475 discloses a photocurable artificial nail composition with glossiness containing a urethane (meth) acrylate oligomer, a (meth) acrylic monomer, a polythiol compound, and a photopolymerization initiator. The document discloses a gel nail with improved photocurability by adding a polythiol compound to a (meth) acrylic monomer, and correspondingly, it is not easily affected by the curing inhibition of oxygen even at the interface in contact with oxygen, and the surface curability is improved. Summary of the invention

[0003] However, the cured product of the composition described in Japanese Patent Application Publication No. 2017-210475 may have fine scratches on the surface due to external friction with a rag, cotton products, etc., which may impair the glossiness. On the other hand, for gel nails that do not contain polythiol compounds, there may be a situation where the surface curability is reduced due to the influence of curing inhibition by oxygen and uncured components remain. In this case, it is necessary to use a rag, cotton products, etc. to wipe off the uncured components on the surface with a solvent, thereby scratching the surface or losing the gloss to a matte state, etc., affecting the surface of the cured product. In this way, it is easy to cause fine scratches on the surface of the cured product due to external friction with a rag, cotton products, etc., and it is difficult to present sufficient glossiness.

[0004] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a photocurable resin composition for nails or artificial nails that can form a cured product having excellent abrasion resistance and high gloss.

[0005] The gist of the present invention is described below.

[0006] [1] A photocurable composition for nails or artificial nails, comprising the following components (A) to (E), wherein when component (C) contains component (c-1), component (D) contains no monofunctional (meth)acrylate, or the content of the monofunctional (meth)acrylate in component (D) is 50% by mass or less based on the total of component (D):

[0007] (A) component: urethane-modified (meth)acrylate oligomer;

[0008] (B) component: (meth)acrylate having a bisphenol skeleton;

[0009] (C) component: at least one (meth)acrylate selected from the group consisting of (c-1) component and (c-2) component (excluding (A) component and (B) component),

[0010] Component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton,

[0011] (c-2) component: (meth)acrylate having an isocyanurate skeleton;

[0012] Component (D): (meth)acrylate other than components (A) to (C);

[0013] (E) Component: photoinitiator.

[0014] [2] In the photocurable composition for a nail or an artificial nail according to [1], the content of the component (B) is 30 parts by mass or more and 90 parts by mass or less relative to 100 parts by mass of the component (A).

[0015] [3] In the photocurable composition for nails or artificial nails according to [1] or [2], the component (D) is one or more selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates and trifunctional (meth)acrylates.

[0016] [4] The photocurable composition for a nail or an artificial nail according to any one of [1] to [3], further comprising an ultraviolet absorber.

[0017] [5] The photocurable composition for nails or artificial nails according to [4], wherein the ultraviolet absorber is a hydroxybenzophenone derivative.

[0018] [6] The photocurable composition for a nail or an artificial nail according to any one of [1] to [5], wherein the photocurable composition for a nail or an artificial nail is used to form a top coat layer. DETAILED DESCRIPTION

[0019] Next, the present invention will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and various changes can be made within the scope of the present invention. In addition, the embodiments described in this specification can be combined in any way to form other embodiments.

[0020] Throughout this specification, expressions in the singular form, unless otherwise specified, should be understood as also including the concept of its plural form. Therefore, articles in the singular form (for example, "a", "an", "the", etc. in English), unless otherwise specified, should be understood as also including the concept of its plural form. In addition, the terms used in this specification, unless otherwise specified, should be understood as being used in the sense commonly used in the field. Therefore, unless otherwise defined, all specialized terms and scientific and technical terms used in this specification have the same meaning as the general understanding of technicians in the field to which the present invention belongs. In the event of a conflict, this specification (including definitions) takes precedence.

[0021] It should be noted that in this specification, the use of "X to Y" refers to a range that includes the numerical values ​​(X and Y) recorded before and after it as the lower limit and upper limit, and means "above X and below Y". In addition, regarding concentration and %, unless otherwise specified, they represent mass concentration and mass %, respectively. Regarding ratios, unless otherwise specified, they refer to mass ratios. In addition, unless otherwise specified, operations and measurements of physical properties are carried out under the conditions of room temperature (20-25°C) / relative humidity 40-50%RH. In addition, "A and / or B" refers to each of A and B and their combinations.

[0022] One embodiment of the present invention is a photocurable resin composition for a nail or an artificial nail, comprising the following components (A) to (E):

[0023] (A) component: urethane-modified (meth)acrylate oligomer;

[0024] (B) component: (meth)acrylate having a bisphenol skeleton;

[0025] (C) component: at least one (meth)acrylate selected from the group consisting of (c-1) component and (c-2) component (excluding (A) component and (B) component),

[0026] Component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton,

[0027] (c-2) component: (meth)acrylate having an isocyanurate skeleton;

[0028] Component (D): (meth)acrylate other than components (A) to (C);

[0029] (E) ingredient: photoinitiator;

[0030] When the component (C) contains the component (c-1), the monofunctional (meth)acrylate is not contained as the component (D), or the content of the monofunctional (meth)acrylate as the component (D) is more than 0 and less than 50% by mass relative to the total of the component (D). By means of the photocurable resin composition for nails or artificial nails of such a constitution, a cured product having excellent abrasion resistance and high gloss can be formed. Thus, the photocurable resin composition for nails or artificial nails involved in one embodiment of the present invention will not scratch the surface even if it is wiped after photocuring, and can present excellent gloss. In addition, by means of the photocurable composition of the present invention, a cured product having excellent luster even if it is wiped after photocuring can be obtained. It should be noted that in the present invention, "glossy" means that the glossiness measurement described later is 85% or more, and in contrast, "glossy" means that when the surface is visually confirmed from multiple directions, the surface can be confirmed to be flat and smooth from any direction and the gloss can be confirmed from any direction.

[0031] <(A)Component>

[0032] The photocurable composition of the present invention contains a urethane-modified (meth)acrylate oligomer as component (A). Hereinafter, acryloyl and methacryloyl are collectively referred to as (meth)acryloyl. Thus, the term "(meth)acryloyl" includes acryloyl (H 2 C=CH-C(=O)-) and methacryloyl (H 2 C=C(CH 3 )-C(=O)-). A compound having a (meth)acryloyl group is also referred to as a (meth)acrylate. The term "(meth)acrylate" includes both acrylate and methacrylate, and the term "(meth)acrylic acid" includes both acrylic acid and methacrylic acid. The (meth)acryloyl group may exist in the form of a (meth)acryloyloxy group.

[0033] Urethane modified (meth)acrylate oligomers are (meth)acrylate oligomers having urethane bonds, and any oligomer having at least one urethane bond and one (meth)acryloyl group can be used. When urethane (meth)acrylate oligomers are added, the adhesion to nails or artificial nails is improved, and the curability and strength of the photocurable composition (coating film) are improved. "Oligomer" refers to a polymer having a repeating unit (monomer unit) (containing repeating units other than (meth)acrylate monomers) repeated from 2 to several dozen times.

[0034] There are no particular restrictions on component (A) as long as it is an oligomer having one or more carbamate bonds and (meth)acryloyl groups, but it preferably contains 2 to 6 (meth)acryloyl groups, more preferably 2 to 5 (meth)acryloyl groups, particularly preferably 2 to 3 (meth)acryloyl groups, and most preferably 2 (meth)acryloyl groups. In addition, the (meth)acryloyl group of component (A) is preferably an acryloyl group. It should be noted that in addition to carbamate bonds and (meth)acryloyl groups, it may also have a carboxyl group, a phosphoric acid group, a hydroxyl group, etc., and may further have other functional groups.

[0035] The weight average molecular weight of the oligomer of component (A) is preferably 1000 to 100000, more preferably 1200 to 30000, further preferably 1500 to 20000, particularly preferably 2000 to 15000, and most preferably 3000 to 10000. As long as it is within such a range, the curing property of the cured product can be improved while maintaining a good viscosity for workability. It should be noted that in this specification, the weight average molecular weight is the value obtained by measuring by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0036] From the viewpoint of improving durability and having good photocurability, component (A) is most preferably a carbamate-modified acrylate oligomer having a weight average molecular weight of 3000 to 6000 and containing 2 to 5 acryloyl groups per molecule. In one embodiment, component (A) contains 2 to 5 (meth)acryloyl groups (preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2) per molecule, and has a weight average molecular weight of 3000 to 6000 (preferably 3000 to 5000, more preferably 3200 to 5500, and particularly preferably 3300 to 4000). With such a structure, no heat is generated during photocuring, and rapid curing can be achieved. Furthermore, the surface of the cured product has no sticky residue and exhibits gloss (especially luster).

[0037] The urethane-modified (meth)acrylate oligomer can be synthesized by a known method, and known methods include the synthesis of (meth)acrylic acid by forming a urethane bond between a polyol and a polyisocyanate to add a compound having a hydroxyl group and a (meth)acryloyl group in the molecule to the remaining (unreacted) isocyanate group.

[0038] As the polyol, there can be mentioned a polyol compound having two or more hydroxyl groups in the molecule, specifically, polyether polyol, polyester polyol, caprolactone diol, bisphenol polyol, polyisoprene polyol, hydrogenated polyisoprene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, castor oil polyol, polycarbonate diol, etc. Among them, polyether polyol (preferably polyether diol) is preferably used because a polyether skeleton is introduced from the viewpoint of presenting glossiness. These can be used alone or in combination of a plurality.

[0039] As polyisocyanates, compounds having two or more isocyanate groups in the molecule can be cited, specifically, aromatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates. As aromatic polyisocyanates, 2,4-benzylidene diisocyanate, 2,6-benzylidene diisocyanate, 1,3-phenylenedimethyl diisocyanate, 1,4-phenylenedimethyl diisocyanate, tetramethylphenylenedimethyl diisocyanate, diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane triisocyanate, etc. can be cited. As alicyclic polyisocyanates, isophorone diisocyanate, bis(4-isocyanatocyclohexyl)methane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, norbornane diisocyanate, dicycloheptane triisocyanate, etc. can be cited. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and 1,6,11-undecane triisocyanate. Among them, diisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate are preferred.

[0040] Examples of compounds having a hydroxyl group and a (meth)acryloyl group include mono(meth)acrylates of diols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol, and mono(meth)acrylates or di(meth)acrylates of triols such as trimethylolethane, trimethylolpropane, and glycerol. These may be used alone or in combination.

[0041] As component (A), polyether skeleton urethane (meth) acrylate oligomers are preferably used, and polyether skeleton difunctional urethane (meth) acrylate oligomers are more preferably used. However, other urethane (meth) acrylate oligomers, such as polyester skeleton urethane (meth) acrylate oligomers, polycaprolactone skeleton urethane (meth) acrylate oligomers, and polycarbonate skeleton urethane (meth) acrylate oligomers, may be used in combination.

[0042] In one embodiment, the component (A) is a compound represented by the following chemical formula (a-1):

[0043] [Chemistry 1]

[0044]

[0045] In the formula,

[0046] L 1 is an alkylene group, a cycloalkylene group, an arylene group, or a combination thereof,

[0047] L 2 Alkylene, arylene, polyoxyalkylene (*-[A 1 -O] n2 -A 1 -*), poly(oxycarbonylalkylene) group, poly(oxycarbonyloxyalkylene) group, or a combination thereof,

[0048] At this time, A 1 is ethylene, propylene, trimethylene, or tetramethylene, n2 is an integer from 0 to 100,

[0049] X 1 and X 2 Each independently has the following structure:

[0050] [Chemistry 2]

[0051]

[0052] In the formula,

[0053] R 11 , R 12 and R 15 are each independently a hydrogen atom or a methyl group,

[0054] R 14 is a hydrogen atom, a methyl group, or an ethyl group,

[0055] A 2 is ethylene, propylene, trimethylene, or tetramethylene,

[0056] n 1 An integer from 1 to 100.

[0057] In one embodiment, L in the above chemical formula (a-1) 2 Contains polyoxyalkylene. When component (A) contains molecules of such a structure, the cured product obtained by photocuring the photocurable composition can have a glossy surface. In one embodiment, L in the above chemical formula (a-1) 2 It is composed only of polyoxyalkylene groups.

[0058] In this specification, * represents a bonding point with other atoms or atomic groups.

[0059] In the present specification, "alkylene" refers to a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, 1 to 10 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. Examples of the alkylene group include, but are not limited to, methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene.

[0060] In this specification, "oxyalkylene" refers to a group represented by formula (a-5):

[0061] *-OA 3 -* Formula (a-5)

[0062] In the formula, A 3 It is an alkylene group.

[0063] Examples of the oxyalkylene group include oxyethylene, oxypropylene, oxytrimethylene, and oxytetramethylene, but are not limited to these.

[0064] In the present specification, "arylene group" refers to a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, 6 to 20 carbon atoms, 6 to 15 carbon atoms, or 6 to 10 carbon atoms. Examples of the arylene group include, but are not limited to, phenylene, tolylene, xylene and naphthalene.

[0065] In this specification, "substituted" means that a hydrogen atom is replaced by another atom or a substituent. As the above-mentioned atom or substituent, unless otherwise defined, there can be mentioned a halogen atom; an alkyl group having 1 to 20 carbon atoms, 1 to 10 carbon atoms, or 1 to 6 carbon atoms; an alkoxy group having 1 to 20 carbon atoms, 1 to 10 carbon atoms, or 1 to 6 carbon atoms; an aryl group having 6 to 30 carbon atoms, 6 to 20 carbon atoms, 6 to 15 carbon atoms, or 6 to 10 carbon atoms; or a combination thereof, but it is not limited to these.

[0066] As specific examples of commercial products, UN-6303, KY-11, UN-904, UN-6200, UN-6207, UN-6304, UN-6305, UN-6306, UN-6307, UN-6060S, etc., which are Art Resin series manufactured by Gengami Industries Co., Ltd.; AH-600, AT-600, UA-306H, UA-510H, UF-8001G, etc., which are manufactured by Kyoeisha Chemical Co., Ltd.; SUA-008, SUA-023, which are manufactured by Asia Chemical Industries Co., Ltd.; UV-3310B, UV-6640B, etc., which are purple light (registered trademark) series manufactured by Mitsubishi Chemical Corporation, but are not limited to these. As (A) component, it is not limited to these, and two or more kinds may be used in combination. When two or more (A) components are used, the content of (A) component is its total amount.

[0067] <(B) Component>

[0068] The photocurable composition of the present invention contains a (meth)acrylate having a bisphenol skeleton as the (B) component. However, the (B) component excludes the (A) component. As the (B) component, a (meth)acrylate monomer having a bisphenol skeleton is preferred, and more preferably two or more (meth)acryloyl groups are bonded to the bisphenol skeleton directly or through a divalent linking group. Here, the bisphenol skeleton refers to skeletons such as bisphenol A type, bisphenol F type, and novolac phenol type. It can be synthesized by addition reaction of (meth)acrylic acid and the like to a polyol having a bisphenol skeleton or an epoxy resin having a bisphenol skeleton, and ring-opening polymerization, but is not limited to these. In the present invention, the (B) component is preferably bisphenol A type from the viewpoint of improving the strength and curability of the cured product.

[0069] The number of (meth)acryloyl groups in the component (B) per molecule is not particularly limited, but preferably 2 to 5 (meth)acryloyl groups per molecule, more preferably 2 to 3 (meth)acryloyl groups per molecule, and even more preferably 2 (meth)acryloyl groups per molecule.

[0070] In the photocurable composition of the present invention, from the viewpoint of reducing the viscosity, it is preferred that the component (B) does not have a hydroxyl group in the molecule. 2 -Base (here, R 2 is a divalent alkylene group). In one embodiment, the component (B) is an alkylene oxide-modified bisphenol skeleton (meth)acrylate (also known as alkoxylated bisphenol skeleton (meth)acrylate). For example, the most preferred component (B) is a compound represented by the following general formula 1.

[0071] [Chemistry 3]

[0072]

[0073] Here, in general formula 1, R 1 Each independently represents a hydrogen atom or a monovalent alkyl group, and R 2 Each independently represents a divalent alkylene group, R 3 Each independently represents a hydrogen atom or a methyl group, and n represents an integer of 1 or greater.

[0074] As a monovalent alkyl group, a linear, branched or alicyclic alkyl group having 1 to 20 carbon atoms is preferred, a linear or branched alkyl group having 1 to 10 carbon atoms is more preferred, and a linear or branched alkyl group having 1 to 5 carbon atoms is further preferred. As a monovalent alkyl group, for example, a methyl group, an ethyl group, a propyl group, a n-butyl group, a tert-butyl group, a n-hexyl group, a n-octyl group, etc. are mentioned. As a divalent alkylene group, a linear, branched or alicyclic alkylene group having 1 to 20 carbon atoms is preferred, a linear or branched alkylene group having 1 to 10 carbon atoms is more preferred, and a linear or branched alkylene group having 1 to 5 carbon atoms is further preferred. As a divalent alkylene group, for example, a methylene group, an ethylene group, a propylene group, a n-butylene group, a n-hexylene group, a n-octylene group, etc. are mentioned.

[0075] Here, R is preferred 2 Methyl, R 2 is ethylene or propylene, R 3 It is a methyl group, and n is 1 or more and 5 or less.

[0076] In one embodiment, component (B) is a (meth)acrylate monomer having a bisphenol skeleton and having 2 to 5 (preferably 2 to 3) (meth)acryloyl groups per molecule. In addition, in one embodiment, component (B) is a (meth)acrylate monomer having (meth)acryloyl groups attached to both ends of an alkylene oxide-modified bisphenol. With such a configuration, rapid curing is possible. As component (B), two or more may also be used in combination.

[0077] The viscosity (25° C.) of the component (B) is preferably 400 to 3000 mPa·s, more preferably 500 to 2500 mPa·s, and even more preferably 800 to 2000 mPa·s.

[0078] Specific examples of the component (B) include NK ESTER BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, and BPE-1300N manufactured by Shin-Nakamura Chemical Co., Ltd.; and FANCRYL FA-324MG, FA-321M, and FA-3218M manufactured by Hitachi Chemical Co., Ltd., but the present invention is not limited to these.

[0079] In the photocurable composition of the present invention, the content of component (B) is preferably 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of component (A), more preferably 20 parts by mass or more and 95 parts by mass or less, further preferably 30 parts by mass or more and 90 parts by mass or less, particularly preferably 40 parts by mass or more and 85 parts by mass or less, and most preferably 50 parts by mass or more and 85 parts by mass or less. If the content of component (B) is 10 parts by mass or more, a cured product with good curability and difficult to scratch is formed, and if the content of component (B) is 100 parts by mass or less, the viscosity of the composition is reduced and it becomes easy to apply. When two or more components (B) are used, the content of component (B) is the total amount thereof.

[0080] <(C) Ingredients>

[0081] The photocurable composition of the present invention contains one or more selected from the group consisting of component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton: and component (c-2): (meth)acrylate having an isocyanurate skeleton as component (C). Component (C) that can be used in the present invention contains one or more selected from the group consisting of component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton: and component (c-2): (meth)acrylate having an isocyanurate skeleton. However, component (C) excludes component (A) and component (B). Here, the alicyclic hydrocarbon skeleton is shown as a cyclic aliphatic, including a saturated cyclic aliphatic or an unsaturated cyclic aliphatic, but in order to maintain transparency, it is preferably a saturated cyclic aliphatic. It should be noted that (meth)acrylate having an alicyclic hydrocarbon skeleton and an isocyanurate group is component (c-2). That is, component (c-1) excludes (meth)acrylate having an isocyanurate group.

[0082] (c-1) ingredient

[0083] As the component (c-1), it is sufficient to be a (meth)acrylate having an alicyclic hydrocarbon skeleton, but it is preferably a (meth)acrylate monomer having an alicyclic hydrocarbon skeleton (cycloaliphatic), and more preferably a monomer having two or more (meth)acryloyl groups bonded directly and through a divalent linking group on the alicyclic hydrocarbon skeleton (cycloaliphatic). The alicyclic hydrocarbon skeleton is also referred to as a cycloaliphatic. In the case where the component (C) contains the component (c-1), it is necessary not to contain a monofunctional (meth)acrylate as the component (D), or the content of the monofunctional (meth)acrylate contained as the component (D) is 50% by mass or less relative to the total mass of the component (D) described later. In the case where the component (C) contains the component (c-1), when the content of the monofunctional (meth)acrylate contained as the component (D) exceeds 50% by mass, the wear resistance is reduced and the surface gloss after wiping is reduced.

[0084] The component (c-1) preferably has 2 to 5 (meth)acryloyl groups in one molecule, more preferably 2 to 3, and even more preferably 2.

[0085] The alicyclic hydrocarbon skeleton (cycloaliphatic) possessed by the component (c-1) may have aliphatic side chains, or may be a monocyclic or crosslinked ring polycyclic (bicyclic, tricyclic, etc.) aliphatic. The cycloaliphatic constituting the alicyclic hydrocarbon skeleton is preferably a saturated or unsaturated cycloaliphatic having 4 to 20 carbon atoms, more preferably a saturated or unsaturated cycloaliphatic having 5 to 12 carbon atoms, and still more preferably a saturated or unsaturated cycloaliphatic having 5 to 10 carbon atoms.

[0086] Examples of the cyclic aliphatic ring include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a cycloheptane ring, a cyclooctane ring, a norbornane ring, a norbornene ring, a bornane ring, an adamantane ring, a tetralin ring, a bicyclo[2.2.2]octane ring, a dicyclopentane ring, a dicyclopentadiene ring, a tricyclodecane ring, and a tricyclodecene ring. Therefore, the component (c-1) is preferably a (meth)acrylate monomer having one or more cyclic aliphatic rings selected from the group consisting of a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a cycloheptane ring, a cyclooctane ring, a norbornane ring, a norbornene ring, a bornane ring, an adamantane ring, a tetralin ring, a bicyclo[2.2.2]octane ring, a dicyclopentane ring, a dicyclopentadiene ring, a tricyclodecane ring and a tricyclodecene ring and 2 to 5 (meth)acryloyl groups.

[0087] As the component (c-1), cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dihydroxymethyl tricyclodecane di(meth)acrylate (another name: tricyclodecane dimethanol diacrylate), dicyclopentenyl di(meth)acrylate, ethylene oxide-modified dicyclopentenyl di(meth)acrylate, etc. can be cited, but it is not limited to these. As the component (c-1), it is particularly preferred to contain dihydroxymethyl tricyclodecane diacrylate. As the component (c-1), two or more kinds can also be used in combination.

[0088] Specific examples of the component (c-1) include DCP-A of the Light Acrylate series manufactured by Kyoeisha Chemical Co., Ltd. and IRR214-K (EBECRYL 130) manufactured by Daicel-Allnex Corporation, but are not limited to these.

[0089] In the photocurable composition of the present invention, the content of component (c-1) is preferably 0.1 to 100 parts by mass, more preferably 0.2 to 80 parts by mass, further preferably 0.3 to 70 parts by mass, particularly preferably 0.5 to 60 parts by mass, and most preferably 0.7 to 55 parts by mass, relative to 100 parts by mass of component (A), and the content of component (c-1) is preferably 0.1 to 100 parts by mass, more preferably 0.2 to 80 parts by mass, further preferably 0.3 to 70 parts by mass, particularly preferably 0.5 to 60 parts by mass, and most preferably 0.7 to 55 parts by mass. When the content of component (c-1) is 0.1 parts by mass or more, the surface gloss after wiping becomes better, and when the content of component (c-1) is 100 parts by mass or less, the coating property is improved and the workability is improved. When two or more components (c-1) are used, the content of component (c-1) is the total amount thereof.

[0090] (c-2) ingredient

[0091] As the component (c-2), any (meth)acrylate having an isocyanurate skeleton may be used, but preferably a (meth)acrylate monomer having an isocyanurate skeleton, and more preferably a monomer having two or more (meth)acryloyl groups bonded to the isocyanurate skeleton directly or via a divalent linking group. It should be noted that even when the (meth)acrylate group having an isocyanurate skeleton has an alicyclic hydrocarbon skeleton, it is used as the component (c-2) when it has an isocyanurate group.

[0092] The component (c-2) preferably has 2 to 5 (meth)acryloyl groups in one molecule, more preferably 2 to 3, and even more preferably 3.

[0093] The component (c-2) is a compound having a structure represented by the following general formula 2.

[0094] [Chemistry 4]

[0095]

[0096] Here, R 4 are independent organic groups, R 4 At least two of the organic groups contain (meth)acryloyl groups.

[0097] As the component (c-2), tris (acryloyloxyethyl) isocyanurate, bis (acryloyloxyethyl) isocyanurate, caprolactone-modified isocyanurate acrylate, etc. can be cited, but it is not limited to these. From the viewpoint of the glossiness of the surface after curing, the component (C) is particularly preferably a compound having two or more (meth)acryloyl groups in one molecule. In addition, it is particularly preferred to contain caprolactone-modified tris-(2-acryloyloxyethyl) isocyanurate as the component (c-2). As the component (c-2), two or more types can also be used in combination.

[0098] In the photocurable composition of the present invention, the content of component (c-2) is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of component (A), more preferably 0.5 to 80 parts by mass, further preferably 1 to 70 parts by mass, particularly preferably 5 to 60 parts by mass, and most preferably 10 to 50 parts by mass. When the content of component (c-2) is 0.1 parts by mass or more, the surface gloss after wiping becomes better, and when the content of component (c-2) is 100 parts by mass or less, the coating property is improved and the workability is improved. When two or more components (c-2) are used, the content of component (c-2) is the total amount thereof.

[0099] Specific examples of the component (c-2) include NK ESTERA9300, A9300-1CL, and A-9200YN manufactured by Shin-Nakamura Chemical Industry Co., Ltd., but the invention is not limited to these.

[0100] The content of the component (C) is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the component (A), more preferably 0.1 to 80 parts by mass, further preferably 0.1 to 60 parts by mass, and particularly preferably 0.5 to 55 parts by mass. When the content of the component (C) is 0.1 parts by mass or more, the viscosity of the composition is reduced, and the operation is easy. When the content of the component (C) is 100 parts by mass or less, the curability is good. In addition, although the clear reason is unknown, in order to present the gloss after curing, when the component (C) contains the component (c-1), it is necessary not to contain a monofunctional (meth) acrylate as the component (D) described later, or the content of the monofunctional (meth) acrylate contained as the component (D) is 50% by mass or less relative to the total mass of the component (D). Although both the component (c-1) and the component (c-2) have a cyclic skeleton, it is speculated that when a certain amount of a monofunctional (meth) acrylate that can reduce the crosslinking density is added, the gloss of the cured product will be different. In addition, content of (C)component is the total amount when using (c-1)component and (c-2)component.

[0101] <(D) Component>

[0102] The photocurable composition of the present invention contains (meth)acrylates other than components (A) to (C) as component (D). That is, component (D) is a (meth)acrylate excluding urethane-modified (meth)acrylate oligomers and (meth)acrylates having a bisphenol skeleton, an alicyclic hydrocarbon skeleton, and an isocyanurate skeleton. Component (D) may be used alone or in combination of two or more.

[0103] As the component (D) that can be used in the present invention, a (meth)acrylate having one or more (meth)acryloyl groups per molecule is preferred (however, the component (D) excludes the components (A) to (C)). As the component (D), any compound having a (meth)acryloyl group other than the components (A) to (C) can be used. Specifically, it refers to a (meth)acrylate monomer and a (meth)acrylate oligomer. In this specification, "oligomer" refers to a compound having a structure in which a plurality of repeating units (monomer units) are bonded, and the molecular weight or weight average molecular weight exceeds 1000. Unless otherwise specified, even if the compound itself is further polymerized by polymerization, it is not referred to as a "monomer" but as an "oligomer". In addition, in this specification, a compound having a structure in which a plurality of repeating units (monomer units) are bonded, and the molecular weight or weight average molecular weight is 1000 or less is referred to as a "monomer". The component (D) is preferably liquid at 25°C and can be used as long as it has good compatibility with the components (A) to (C) of the present invention.

[0104] As component (D), it is preferred that the (meth)acrylate monomers other than components (B) to (C) are (meth)acrylate monomers excluding (meth)acrylates having a bisphenol skeleton, an alicyclic hydrocarbon skeleton and an isocyanurate skeleton. If heat generation during photocuring is taken into consideration, component (D) preferably has 1 to 6 (meth)acryloyl groups per molecule, more preferably 1 to 4 (meth)acryloyl groups per molecule, and further preferably 1 to 3 (meth)acryloyl groups per molecule. In addition, component (D) is preferably one or more selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates and trifunctional (meth)acrylates.

[0105] Specific examples of (meth)acrylate oligomers include (meth)acrylate oligomers having an ester bond in the molecule, but are not limited thereto. In addition, the component (A) that can be used in the present invention also includes compounds having one or more epoxy groups and one or more (meth)acryloyl groups in one molecule.

[0106] As a (meth)acrylate oligomer having an ester bond, there is known a method of synthesizing a (meth)acrylate oligomer by forming an ester bond from a polyol and a polycarboxylic acid and adding acrylic acid to an unreacted hydroxyl group, but the method is not limited to this method. Specifically, there can be mentioned Aronix M-6100, M-6200, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, M-9050, etc. manufactured by Toagosei Co., Ltd., and UV-3500BA, UV-3520TL, UV-3200B, UV-3000B, etc. manufactured by Nippon Synthetic Chemical Industry Co., Ltd., but the method is not limited to these.

[0107] The (meth)acrylate monomer may include monofunctional to hexafunctional (preferably monofunctional, difunctional, or trifunctional) (meth)acrylate monomers and (meth)acrylamide monomers. In addition, a plurality of other monomers may be used in combination.

[0108] Specific examples of the monofunctional (meth)acrylate monomer include lauryl (meth)acrylate, stearyl (meth)acrylate, ethyl carbitol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxytetraethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, and the like. Acrylate, butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, 2-ethylhexyl polyethylene glycol (meth) acrylate, 4-hydroxybutyl (meth) acrylate, nonylphenyl polypropylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, etc., but not limited to these. As (D) component, a (meth) acrylate monomer having a hydroxyl group is preferred, for example, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate are more preferred.

[0109] Examples of the monofunctional (meth)acrylate monomer include (meth)acrylate monomers having an acidic group, and particularly include carboxylic acid and phosphoric acid having a (meth)acryloyl group in the molecule. Examples of the carboxylic acid having a (meth)acryloyl group in the molecule include (meth)acryloyl acid, 3-(meth)acryloyloxypropyl succinic acid, 4-(meth)acryloyloxybutyl succinic acid, 2-(meth)acryloyloxyethyl maleic acid, 3-(meth)acryloyloxypropyl maleic acid, 4-(meth)acryloyloxybutyl maleic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 3-(meth)acryloyloxypropyl hexahydrophthalic acid, 4-(meth)acryloyloxybutyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 3-(meth)acryloyloxypropyl phthalic acid, and 4-(meth)acryloyloxybutyl phthalic acid. Examples of the phosphoric acid having a (meth)acryloyl group in the molecule include, but are not limited to, 2-ethylhexyl acid phosphate, 2-hydroxyethyl (methacrylate) acid phosphate, and dibutyl phosphate.

[0110] Specific examples of the difunctional (meth)acrylate monomer include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, ethylene glycol diacrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ethylene oxide-modified neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, etc., but are not limited to these.

[0111] Specific examples of the trifunctional (meth)acrylate monomer include trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate (also known as ethoxylated trimethylolpropane tri(meth)acrylate), and propylene oxide-modified trimethylolpropane tri(meth)acrylate, but are not limited to these.

[0112] Specific examples of the polyfunctional (meth)acrylate monomer having a functional group number of tetra or higher include di(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0113] From the viewpoint of developing surface curability and gloss, the component (D) preferably contains a monofunctional (meth)acrylate having a hydroxyl group in the molecule as the monofunctional (meth)acrylate.

[0114] The component (D) is preferably one or more selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates, and trifunctional (meth)acrylates. In addition, from the viewpoint of suppressing heat generation during the procedure, the component (D) preferably does not contain tetrafunctional or higher (meth)acrylates.

[0115] The component (D) preferably contains one or more species selected from the group consisting of a (meth)acrylate monomer having a hydroxyl group and one or two (meth)acryloyl groups, and a (meth)acrylate monomer having 1 to 3 (meth)acryloyl groups. It is more preferred that it contains one or more species selected from the group consisting of a (meth)acrylate monomer having a hydroxyl group and one or two (meth)acryloyl groups, and a (meth)acrylate monomer having 2 or 3 (meth)acryloyl groups. It is further preferred that it contains one or more species selected from the group consisting of a (meth)acrylate monomer having a hydroxyl group and one (meth)acryloyl group, and a (meth)acrylate monomer having three (meth)acryloyl groups. It is particularly preferred that it contains a (meth)acrylate monomer having a hydroxyl group and one (meth)acryloyl group, and a (meth)acrylate monomer having three (meth)acryloyl groups.

[0116] In the photocurable composition of the present invention, the component (D) preferably has -OR 6 -Base (here, R 6 is a divalent alkylene group). 6 Examples of the alkylene group include ethylene and propylene. In one embodiment, the component (D) is an alkylene oxide-modified (meth)acrylate monomer.

[0117] The content of component (D) is preferably 1 part by mass or more and 60 parts by mass or less relative to 100 parts by mass of component (A), more preferably 2 parts by mass or more and 55 parts by mass or less, further preferably 5 parts by mass or more and 50 parts by mass or less, particularly preferably 8 parts by mass or more and 40 parts by mass or less, and most preferably 10 parts by mass or more and 30 parts by mass or less. When the content of component (D) is 1 part by mass or more, the viscosity of the composition is reduced and the operation is easy. When the content of component (D) is 60 parts by mass or less, the curability is good. When two or more components (D) are used, the content of component (D) is the total amount thereof. It should be noted that when the photocurable composition of the present invention contains component (c-1), the monofunctional (meth) acrylate described later as component (D) is not contained, or the content of the monofunctional (meth) acrylate contained as component (D) is 50% by mass or less relative to the total mass of component (D) described later.

[0118] <(E) Component>

[0119] The component (E) that can be used in the present invention is a photoinitiator. The component (E) is not limited as long as it is a radical-based photoinitiator that generates radical species by energy rays such as visible light, ultraviolet light, X-rays, and electron beams.

[0120] Specific examples of the component (E) include acetophenones such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; and benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3′,4 , 4′-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propionyloxy)ethyl]benzyl ammonium bromide, (4-benzoylbenzyl)trimethylammonium chloride and other benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thiothioxanthone-9-one meso chloride (2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thiothioxanthone-9-one-mesochl oride) and other thioxanthones, but are not limited thereto. Furthermore, a plurality of components (E) may be used in combination.

[0121] The content of the (E) component is preferably 0.1 mass part or more and 20 mass parts or less relative to 100 mass parts of the (A) component, more preferably 1 mass part or more and 18 mass parts or less, and further preferably 5 mass parts or more and 5 mass parts or less. When the content of the (E) component is 0.1 mass parts or more, the photocurability can be maintained. On the other hand, when the content of the (E) component is 20 mass parts or less, the storage stability can be avoided from thickening during storage. The content of the visible light type photoinitiator is preferably 0 mass% or more and 70 mass% or less relative to the (E) component as a whole, and the cured product is difficult to turn yellow. Here, the visible light type photoinitiator is the photoinitiator with the strongest light absorption in the visible light region, indicating an acylphosphine oxide-based photopolymerization initiator mainly containing phosphorus atoms. Specifically, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. can be cited, but are not limited to these.

[0122] <Other ingredients>

[0123] The present invention may further contain an ultraviolet absorber. However, as the ultraviolet absorber, components (A) to (E) are excluded. A preferred ultraviolet absorber is a compound having one phenol group in the molecule, for example, a phenol compound represented by the following general formula 3. Here, R 5 There is only one organic group conjugated with the aromatic ring of phenol, and the rest of R 5 The molecular weight of the ultraviolet absorber is preferably 150 to 600 from the viewpoint of solubility in the components (A) and (B). It can be added to suppress heat generation during curing.

[0124] [Chemistry 5]

[0125]

[0126] In the phenol compound represented by the general formula 3, the organic group conjugated with the aromatic ring of the phenol is preferably a group of the following formula 4, a group of the following formula 5 or a group of the following formula 6, or a group having a skeleton of the following formula 4, the following formula 5 or the following formula 6. As such an ultraviolet absorber, for example, 2-hydroxy-4-n-octyloxybenzophenone can be cited, but it is not limited thereto.

[0127] [Chemistry 6]

[0128]

[0129] The content of the ultraviolet absorber is preferably 0.01 to 5.0 parts by mass relative to 100 parts by mass of (A) component. When the content of the ultraviolet absorber is 0.01 parts by mass or more, the heat generation during photocuring can be suppressed, and when it is 5.0 parts by mass or less, the photocurability can be maintained, and in particular, the surface curability can be maintained. In addition, relative to the entire composition, the ultraviolet absorber content is preferably 0.001 to 10.0 parts by mass. When the ultraviolet absorber is 0.001% by mass or more, the heat generation can be suppressed, and when it is 10.0% by mass or less, the storage stability can be well maintained.

[0130] In the present invention, appropriate amounts of additives such as polythiol compounds, (meth)acrylamide monomers, coupling agents, inorganic fillers, organic fillers, pigments, dyes and other colorants, antioxidants, polymerization inhibitors, defoamers, leveling agents, rheology control agents, etc. can be added within the range that does not impair the characteristics of the present invention. By adding these, a composition or a cured product thereof having excellent resin strength, workability, storage stability, etc. can be obtained.

[0131] In the present invention, a polythiol compound may be contained within a range that does not impair the characteristics of the present invention. A polythiol compound refers to a compound having two or more thiol groups in one molecule. It is known that there are photocurable compositions to which polythiol compounds are added, but polythiol compounds have an unpleasant odor and, when in contact with silver ornaments, accelerate oxidation and blackening. Specific examples of polythiol compounds include aliphatic polythiol compounds, aromatic polythiol compounds, polythiol compounds having thioether bonds, and the like, but are not limited thereto.

[0132] Examples of the aliphatic polythiol compound having two thiol groups include 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,12-dodecanedithiol, 2,2-dimethyl-1,3-propanedithiol, 3-methyl-1,5-pentanedithiol, 2- Methyl-1,8-octanedithiol, 1,4-cyclohexanedithiol, 1,4-bis(mercaptomethyl)cyclohexane, 1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol, bicyclo[2,2,1]heptane-exo-cis-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, bis(2-mercaptoethyl)ether, ethylene glycol bis(2-mercaptoacetate), and ethylene glycol bis(3-mercaptopropionate), etc., but are not limited to these.

[0133] Examples of aliphatic polythiol compounds having three thiol groups include, but are not limited to, 1,1,1-tris(mercaptomethyl)ethane, 2-ethyl-2-mercaptomethyl-1,3-propanedithiol, 1,2,3-propanetrithiol, trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), and tris[(mercaptopropionyloxy)-ethyl]isocyanurate.

[0134] Examples of the aliphatic polythiol compound having four or more thiol groups include pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and dipentaerythritol hexa-3-mercaptopropionate, but are not limited thereto.

[0135] Examples of the aromatic polythiol compound include 1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,2-bis(mercaptomethyl)benzene, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 1,2-bis(2-mercaptoethyl)benzene, 1,3-bis(2-mercaptoethyl)benzene, 1,4-bis(2-mercaptoethyl)benzene, 1,2-bis(2-mercaptoethyleneoxy)benzene, 1,3-bis(2-mercaptoethyleneoxy)benzene, 1,4-bis(2-mercaptoethyleneoxy)benzene, 1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris(mercaptomethyl)benzene, 1,2,4-tris(mercaptoethyl)benzene, 1,3,5-tris(mercaptomethyl)benzene, 1,2,3-tris(2-mercaptoethyl)benzene, 1,2,4-tris(2-mercaptoethyl)benzene, 1,3,5-tris(2-mercaptoethyl)benzene, 1,2,3-tris(2-mercaptoethyleneoxy)benzene, 1,2,4-tris(2-mercaptoethyleneoxy)benzene, 1,3,5-tris(2-mercaptoethyleneoxy)benzene, 1,2,3,4-tetramercaptobenzene, 1,2,3,5-tetramercaptobenzene, 1,2,4,5-tetramercaptobenzene, 1,2,3,4-tetrakis(mercaptomethyl)benzene, 1,2,3,5-tetrakis(mercaptomethyl)benzene, 1,2,4,5-tetrakis(mercaptomethyl)benzene, 1,2,3,4-tetrakis(2-mercaptoethyl)benzene Benzene, 1,2,3,5-tetrakis(2-mercaptoethyl)benzene, 1,2,4,5-tetrakis(2-mercaptoethyl)benzene, 1,2,3,4-tetrakis(2-mercaptoethyleneoxy)benzene, 1,2,3,5-tetrakis(2-mercaptoethyleneoxy)benzene, 1,2,4,5-tetrakis(2-mercaptoethyleneoxy)benzene, 2,2'-mercaptobiphenyl, 4,4'-thiobis-benzenethiol, 4,4'-dimercaptobiphenyl, 4,4'-dimercaptobibenzyl, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,4-naphthalenedithiol, 1,5-naphthalenedithiol, 2,6-naphthalenedithiol, 2,7-naphthalenedithiol, 2,4-dimethylbenzene-1,3-dithiol, 4,5-dimethylbenzene-1,3-dithiol alcohol, 9,10-anthracenedimethanethiol, 1,3-bis(2-mercaptoethylthio)benzene, 1,4-bis(2-mercaptoethylthio)benzene, 1,2-bis(2-mercaptoethylthiomethyl)benzene, 1,3-bis(2-mercaptoethylthiomethyl)benzene, 1,4-bis(2-mercaptoethylthiomethyl)benzene, 1,2,3-tris(2-mercaptoethylthio)benzene, 1,2,4-tris(2-mercaptoethylthio)benzene, 1,3,5-tris(2-mercaptoethylthio)benzene, 1,2,3,4-tetrakis(2-mercaptoethylthio)benzene, 1,2,3,5-tetrakis(2-mercaptoethylthio)benzene, and 1,2,4,5-tetrakis(2-mercaptoethylthio)benzene, etc., but are not limited to these.

[0136] Examples of the polythiol compound having a thioether bond include bis(2-mercaptoethyl)sulfide, bis(2-mercaptoethylthio)methane, 1,2-bis(2-mercaptoethylthio)ethane, 1,3-bis(2-mercaptoethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, tetrakis(2-mercaptoethylthiomethyl)methane, 1,2-bis(2-mercaptoethylthio)propanethiol, 2,5-dimercapto-1,4-dithiane, bis(2-mercaptoethyl)disulfide, 3,4-thiophenedithiol, 1,2-bis(2-mercaptoethyl)thio-3-mercaptopropane, and bis-(2-mercaptoethylthio-3-mercaptopropane)sulfide, but are not limited thereto.

[0137] Specific examples of polythiol compounds having a secondary thiol group include pentaerythritol tetrakis (3-mercaptobutyrate), 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane tris (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane tris (3-mercaptobutyrate), etc., but are not limited to these. As commercial products, PEMP manufactured by SC Organic Chemical Co., Ltd. and PE1, BD1, NR1 of the Karenz MT (registered trademark) series manufactured by Showa Denko K.K. can be cited, but are not limited to these.

[0138] In the present invention, (meth)acrylamide monomers can be added within the range that does not damage the characteristics of the present invention. As specific examples, dimethyl (meth)acrylamide, (meth)acryloyl morpholine, diethyl (meth)acrylamide, etc. can be cited, but they are not limited to these. Although the clear reason is unknown, from the viewpoint of improved durability, the monomer preferably includes a (meth)acrylamide monomer. In the present invention, as specific examples of (meth)acrylamide monomers, DMAA, ACMO, DEAA, etc. manufactured by KJ CHEMICALS Co., Ltd. are known, but they are not limited to these.

[0139] In the present invention, a coupling agent may be added within a range that does not impair the characteristics of the present invention. As the coupling agent, a silane coupling agent having an epoxy group, a vinyl group, an acryl group or a methacryl group and a hydrolyzable silyl group, a polyorganosiloxane having a phenyl group and a hydrolyzable silyl group, and / or a polyorganosiloxane having an epoxy group and a hydrolyzable silyl group may be cited, but it is not limited to these. As specific examples of the silane coupling agent, allyl trimethoxy silane, vinyl trimethoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-methacryloxy propyl trimethoxy silane, 3-acryloxy propyl trimethoxy silane, 3-chloropropyl trimethoxy silane may be cited, but it is not limited to these.

[0140] In the present invention, fillers such as inorganic fillers and organic fillers can be appropriately added within the scope of not damaging the characteristics of the present invention. By adding fillers, not only can viscosity / thixotropy be adjusted, but also curability and toughness can be adjusted. As inorganic fillers, aluminum oxide, silicon oxide, amorphous silicon oxide, etc. can be mentioned, but are not limited to these. On the other hand, as organic fillers, styrene fillers, rubber fillers, core-shell acrylic fillers, etc. can be mentioned, but are not limited to these. Specific products include FUSELEX E-1 manufactured by Ronson Co., Ltd. and AO-802 manufactured by Admafine Co., Ltd. as silicon oxide, and 200 (untreated), R972 (treated with dimethyldichlorosilane), R976 (treated with dimethyldichlorosilane), RY200 (treated with dimethylsilicone), RX200 (treated with hexamethyldisilazane), and R800 (treated with octylsilane) from the Aerosil series manufactured by Nippon Aerosil Co., Ltd. as amorphous silicon oxide, but the present invention is not limited to these.

[0141] There is no particular limitation on the method for preparing the photocurable composition for nails of the present invention, and a conventionally known method can be appropriately adopted. For example, the prescribed amounts of component (A), component (B), component (C), component (D), component (E), and any additional components are weighed separately, added to a mixing kettle one by one or simultaneously in any order, and then mixed using a mixing means such as a planetary mixer, preferably while vacuum degassing. The order of addition is preferably such that component (E) is added last. By adding component (E) last, photopolymerization reaction can be prevented from occurring at an undesirable stage. At this time, there is no particular limitation on the manufacturing conditions, but it is preferably carried out under light-shielding conditions. The mixing temperature is preferably a temperature of 10 to 50° C., and the mixing time is preferably 0.1 to 5 hours.

[0142] When the photocurable composition for nails or artificial nails of the present invention is used as a so-called gel nail, the procedure is performed according to the following steps. Before the procedure, the surface of the human nail is polished with a file or the like, and dust, grease, moisture, etc. are removed with a nail-specific solvent with ethanol as the main component. When applying the present invention, a coating film having a thickness of 100 to 300 μm before curing is formed with a brush or the like. A primer may be used in advance during coating. As an irradiation device during curing, a commercially available LED lamp for gel nails or the like is used. The irradiation time is 15 to 120 seconds, and preferably 20 to 70 seconds if the effect on the fingers is considered.

[0143] Taking the coating properties during application into consideration, the photocurable composition for a nail or an artificial nail of the present invention preferably has a viscosity of 10 Pa·s or less at 25° C., more preferably 5 Pa·s or less.

[0144] When a compound having a (meth)acryloyl group is polymerized by generating free radical species due to energy rays, it is known that polymerization in the area in contact with oxygen is inhibited under the inhibitory effect of oxygen. At this time, uncured components remain on the surface of the cured product, so in most cases, the uncured components are wiped off with a rag, cotton products, etc., or wiped with a rag soaked in a solvent such as ethanol, etc., especially in the top coating used on the outermost surface. The present invention does not scratch the surface of the cured product even if it is wiped with a rag, etc., and it also presents a glossy appearance, so it is suitable for a top coating.

[0145] The cured product formed by photocuring the photocurable composition for nails or artificial nails according to the present invention preferably has an initial gloss (gloss after curing and before abrasion test) of 85% or more, more preferably 87% or more, and further preferably 88% or more. In addition, for the cured product formed by photocuring the photocurable composition for nails or artificial nails according to the present invention, the gloss after the abrasion test is preferably 83% or more, more preferably 85% or more, and further preferably 88% or more. At this time, the change in gloss before and after the abrasion test is preferably 5.0% or less, more preferably 4.0% or less, further preferably 3.0% or less, and particularly preferably 2.0% or less. In this specification, the gloss can be measured by the method described in the examples. In this specification, the abrasion test is performed by the method described in the examples.

[0146] It should be noted that, in the present invention, the value obtained by measuring the glossiness using a high gloss tester manufactured by Horiba, Ltd. serves as a reference for the glossiness of the cured product, but the presence or absence of gloss after visually evaluating the entire surface of the cured product can be regarded as a clear evaluation of the actual glossiness. Therefore, whether the result of the surface gloss based on visual observation is 0 or × is given priority as the gloss evaluation. For example, when comparing the gloss of multiple cured products with a 0 evaluation, the glossiness calculated by the high gloss tester serves as an index, and the glossiness can be compared. Similarly, when comparing the gloss of multiple cured products with a × evaluation, the glossiness calculated by the high gloss tester serves as an index, and the glossiness can be compared.

[0147] Example

[0148] Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0149] [Examples 1 to 7, Comparative Examples 1 to 3]

[0150] To prepare a photocurable composition, the following components are prepared. (The photocurable composition for nails or artificial nails is also referred to as a composition hereinafter.)

[0151] Component (A): Urethane-modified (meth)acrylate oligomer

[0152] · Weight average molecular weight: 3500, polyether urethane acrylate with a functional group number of 2 (Art Resin UN-6303 manufactured by Negami Industries Co., Ltd.)

[0153] Component (B): (meth)acrylate having a bisphenol skeleton

[0154] Ethoxylated bisphenol A dimethacrylate (NKester BPE-80N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) (viscosity (25° C.): 1220 mPa·s)

[0155] (C) component: (meth)acrylate of component (c-1) and / or component (c-2) (excluding component (A) and component (B))

[0156] Component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton

[0157] ·Dimethyloltricyclodecane diacrylate (Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.)

[0158] Component (c-2): (meth)acrylate having an isocyanurate skeleton

[0159] Caprolactone-modified tris-(2-acryloyloxyethyl) isocyanurate (NK ESTER A9300-1CL, manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0160] Component (D): (meth)acrylate other than components (A) to (C)

[0161] · Ethoxylated (9) trimethylolpropane triacrylate (Sartomer SR502, manufactured by Arkema)

[0162] · Dipentaerythritol hexaacrylate (DPHA manufactured by Daicel-Allnex Co., Ltd.)

[0163] · 4-Hydroxybutyl acrylate (4-HBA, manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0164] (E) ingredient: photoinitiator

[0165] 1-Hydroxycyclohexylphenylketone (non-visible light photoinitiator) (IRGACURE 184, manufactured by BASF)

[0166] ·2,4,6-Trimethylbenzoyl-diphenyl-phosphine oxide (visible light photoinitiator) (LUCIRIN TPO manufactured by BASF)

[0167] UV absorber

[0168] 2-Hydroxy-4-n-octyloxybenzophenone (molecular weight: 326) (reagent) (hereinafter referred to as octabenzone)

[0169] Examples 1 to 7 and Comparative Examples 1 to 3 were prepared according to the amounts shown in Table 1 below. The composition was prepared by weighing components (A) to (D) and a UV absorber, adding them to a stirring kettle, and stirring for 30 minutes. Subsequently, component (E) was weighed and stirred while vacuum degassing for 30 minutes. The detailed preparation amounts are shown in Table 1, and the values ​​are all expressed in parts by mass. In addition, the total amount of components (B), the total amount of components (C), the total amount of components (D), and the ratio (mass %) of monofunctional monomers relative to the total amount of components (D) are also recorded.

[0170] [Table 1]

[0171]

[0172] For Examples 1 to 7 and Comparative Examples 1 to 3, the surface state of the cured product was confirmed (before wiping), the surface state of the cured product was confirmed (after wiping), the glossiness was measured (before wiping), the glossiness was measured (after wiping), the heat generation during the procedure was confirmed, and the yellowness was measured. The results are summarized in Table 2.

[0173] [Surface state of cured product (before wiping): "Surface gloss (before wiping)"]

[0174] The composition was applied to a blackened nail with a coating thickness of 100 μm, and irradiated for 30 seconds with a nail LED lamp (rated voltage: 100-110V 50-60Hz power consumption: 36W, wavelength: 350-400nm) to cure the composition and prepare a test piece. According to the following evaluation criteria, the surface gloss (before wiping) was reflected on the LED stand for visual confirmation, and "0" was preferred as the "surface gloss (before wiping)".

[0175] Evaluation Criteria

[0176] ○: The surface is shiny

[0177] ×: The surface is dull.

[0178] [Confirmation of the surface condition of the cured product (after wiping): "Surface gloss (after wiping)"]

[0179] After the surface of the test piece was confirmed in the above-mentioned cured product surface state test (before wiping), the surface was wiped 5 times with a rag soaked in acetone, and then visually confirmed again by reflection from the LED bracket according to the following evaluation criteria as "Surface gloss (after wiping)". Preferably "0".

[0180] 《Evaluation Criteria》

[0181] ○: The surface is shiny

[0182] ×: There are slight scratches on the surface.

[0183] [Glossiness measurement (before wiping): "Glossiness (%) (before wiping)"]

[0184] A test piece (size: thickness 0.8 mm × width 70 mm × length 150 mm) with a transparent aminoalkyd coating electrodeposited on one side of SPCC-SD as a substrate was used. The composition was applied to the electrodeposited surface with a thickness of 100 μm and a conveyor-type ultraviolet irradiator equipped with a high-pressure mercury lamp was used to irradiate the surface with a cumulative light dose of 30 kJ / m 2 Irradiate with light of 365nm wavelength to cure and make a test piece. Use a high gloss tester made by Horiba, Ltd. to measure the glossiness of the cured surface of the test piece at an incident angle of 60° and a light receiving angle of 60°, and use this as "glossiness (%) (before wiping)". In order to make the appearance shiny, the initial glossiness is preferably 85% or more.

[0185] [Glossiness measurement (after wiping): “Glossiness (%) (after wiping)”]

[0186] Using the test piece measured in the above-mentioned glossiness measurement (before wiping), wipe the surface 5 times with a rag soaked in acetone, and measure the glossiness again as "Glossiness (%) (after wiping)". In addition, the "Glossiness change rate (%)" is calculated by "Glossiness change rate (%)" = ("Glossiness after wiping (%)" - "Glossiness before wiping (%)") / "Glossiness before wiping (%)" × 100. From the viewpoint of durability, the glossiness after abrasion is preferably 85% or more. In addition, the glossiness change rate is more preferably -5.0 to 0.0%.

[0187] [Confirmation of fever during treatment]

[0188] After polishing the nails, use a special solvent for nails (main component of ethanol) to remove dust and grease on the surface of the nails. Apply the primer in a wet coating thickness of about 100μm. Apply with a brush. Subsequently, irradiate with a nail LED lamp (rated voltage: 100~110V 50-60Hz power consumption: 36W, wavelength: 350~400nm) for 30 seconds to cure the composition. In the same way, apply the color coating agent and the top coating agent on the surface of the base coating in sequence, and cure them in sequence under the same conditions. The color coating agent uses Super Color EX (color: pastel peach) made by PREGEL, and the top coating uses various compositions. For the same person's fingernails (10), "heat generation during treatment" is evaluated according to the following evaluation criteria. If the subject's sense of pressure is taken into consideration, "0" or "△" is preferred.

[0189] 《Evaluation Criteria》

[0190] ○: No heat sensation

[0191] △: Slightly hot

[0192] ×: Hot.

[0193] [Yellowness measurement]

[0194] The composition was applied to an alkali-free glass plate of 0.7 mm in thickness, 100 mm in width, and 100 mm in length at a thickness of 150 μm and a cumulative light intensity of 30 kJ / m 2 Irradiate with ultraviolet light to cure. Determine the yellowness by visible-ultraviolet spectroscopy. Measure the transmittance in the wavelength range of 800nm ​​to 300nm, and calculate the yellowness according to JIS K7373:2006. The number of tests is n=3, and the average value is calculated as the "yellowness". In order to maintain transparency, the yellowness is preferably 3.0 or less.

[0195] [Table 2]

[0196]

[0197] When comparing Examples 1 to 7 with Comparative Examples 1 to 3, it can be seen that although there is no difference in glossiness change rate and yellowness, in terms of surface gloss after wiping, Comparative Examples 1 to 3 have no surface gloss, while Examples 1 to 7 maintain the surface gloss. In addition, when comparing Examples 1 to 5 with Comparative Example 3, it can be seen that when the component (c-1) is used as the component (C), the surface gloss after wiping is maintained when the content of the monofunctional (meth)acrylate contained as the component (D) is 50% by mass or less relative to the total of the component (D).

[0198] Industrial Applicability

[0199] The present invention will not scratch the surface due to external friction, impact, etc., and can be used as a top coating in the field of nail art.

[0200] This application is based on Japanese Patent Application No. 2022-177271 filed on November 4, 2022, and all the disclosed contents are incorporated herein by reference.

Claims

1. A photocurable composition for nails or artificial nails, in, The following components (A) to (E) are contained, and when the component (C) contains the component (c-1), the component (D) does not contain a monofunctional (meth)acrylate, or the content of the monofunctional (meth)acrylate contained in the component (D) is 1:

1. The total amount of component (D) is 50% by mass or less: (A) component: urethane-modified (meth)acrylate oligomer; (B) component: (meth)acrylate having a bisphenol skeleton; (C) component: at least one (meth)acrylate selected from the group consisting of (c-1) component and (c-2) component, excluding (A) component and (B) component, Component (c-1): (meth)acrylate having an alicyclic hydrocarbon skeleton, (c-2) component: (meth)acrylate having an isocyanurate skeleton; Component (D): (meth)acrylate other than components (A) to (C); (E) Component: photoinitiator.

2. The photocurable composition for nails or artificial nails according to claim 1, in, The content of the component (B) is 30 parts by mass or more and 90 parts by mass or less relative to 100 parts by mass of the component (A).

3. The photocurable composition for nails or artificial nails according to claim 1 or 2, in, The component (D) is one or more selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates, and trifunctional (meth)acrylates.

4. The photocurable composition for nails or artificial nails according to claim 1, in, Furthermore, it contains a UV absorber.

5. The photocurable composition for nails or artificial nails according to claim 4, in, The ultraviolet absorber is a hydroxybenzophenone derivative.

6. The photocurable composition for nails or artificial nails according to claim 1 or 2, in, The photocurable composition for a nail or an artificial nail is used to form a top coating layer.

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