Photocurable composition, cured product, optical material, and method for producing cured product

Abstract

This photocurable composition contains a photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) contains at least one compound selected from the group consisting of compounds represented by formula (1) to formula (5). R1 to R11 are substituents, and n is an integer of 1 to 3.

Description

Photocurable composition, cured product, optical material, and method for producing cured product

[0001] This disclosure relates to photocurable compositions, cured products, optical materials, and methods for producing cured products.

[0002] Conventionally, photocurable compositions that harden when irradiated with light have been known. For example, Patent Document 1 below discloses a photocurable composition that has excellent photocurability and can form a thiourethane resin, containing a specific base generator (a), a specific polyiso(thio)cyanate compound (b), and a polythiol compound (c).

[0003] Patent Document 1: International Publication No. 2023 / 063398

[0004] However, there are cases where it is desired to further reduce the yellowness and improve the hardness of the cured product obtained by curing a photocurable composition. An object of one aspect of this disclosure is to provide a photocurable composition and a method for producing a cured product that can obtain a cured product with reduced yellowness and excellent hardness, as well as a cured product and optical material with reduced yellowness and excellent hardness.

[0005] Means for solving the above problems include the following embodiments: <1> A photocurable composition comprising: a photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) comprises at least one selected from the group consisting of compounds represented by the following formulas (1) to (5).

[0006]

[0007] In formula (1), R １ ~R ４ Each of these independently represents an alkyl group having 1 to 8 carbon atoms, R ５ ~R ８each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (2), R １ ~R ７ each independently represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, and R ８ ~R １１ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (3), n represents an integer of 1 to 3, and R １ ~R ４ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (4), R １ ~R ４ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (5), R １n represents an aromatic hydrocarbon group which is a phenyl group, naphthyl group, anthracenyl group, or phenanthuryl group, or an unsaturated heterocyclic group which is a pyrrolyl group, furfuryl group, imidazolyl group, pyrazolyl group, oxazolyl group, thiazolyl group, triazolyl group, tetrazolyl group, pyridinium group, triazinyl group, or tetradinyl group, and the aromatic hydrocarbon group and the unsaturated heterocyclic group may each be substituted with a halogen atom, alkyl group, alkoxy group, alkylthio group, aryl group, alkenyl group, cycloalkyl group, or heterocyclic group, and may be fused with a heterocyclic ring. In formula (5), n and R ２ ~R ５ n and R in equation (3) are, respectively. １ ~R ４ It is synonymous with [the above].

[0008] <2> The photobase generator (a) generates light at 365 nm, with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ The photocurable composition according to <1>, which is a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 by irradiation with light at a rate of / s. <3> A photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) is irradiated with light at 365 nm with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２A photocurable composition comprising a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 upon irradiation with light at a rate of / s.

[0009] <4> The photocurable composition according to any one of <1> to <3>, wherein the molecular weight of the di(meth)acrylate compound (d) is 1000 or less. <5> The photocurable composition according to any one of <1> to <4>, wherein the di(meth)acrylate compound (d) contains a tricyclodecane structure. <6> The photocurable composition according to any one of <1> to <5>, wherein the di(meth)acrylate compound (d) is at least one of tricyclodecane dimethanol diacrylate and tricyclodecane dimethanol dimethacrylate. <7> The photocurable composition according to any one of <1> to <6>, wherein the content of the photobase generator (a) is 0.05% to 5% by mass with respect to the total amount of the photocurable composition. <8> The photocurable composition according to any one of <1> to <7>, wherein, when the amount of mercapto groups in the polythiol compound (c) is taken as 100 mol%, the sum of the amount of iso(thio)cyanato groups in the polyiso(thio)cyanate compound (b) and the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is 70 mol% to 130 mol%. <9> The photocurable composition according to any one of <1> to <8>, wherein, when the sum of the amount of iso(thio)cyanato groups in the polyiso(thio)cyanate compound (b) and the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is taken as 100 mol%, the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is 1 mol% to 60 mol%. <10> The photocurable composition according to any one of <1> to <9>, wherein the polyiso(thio)cyanate compound (b) comprises at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate.<11> The polythiol compound (c) is 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(mercaptomethyl)- A photocurable composition according to any one of <1> to <10>, comprising at least one selected from the group consisting of 1,4-dithiane, bis(2-mercaptoethyl)sulfide, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithiethane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane. <12> A photocurable composition according to any one of <1> to <11>, used for producing a cured product by irradiation with light-emitting diode light having a wavelength of 340 nm to 500 nm. <13> A cured product of the photocurable composition according to any one of <1> to <12>. <14> An optical material comprising the cured product described in <11>. <15> A method for producing a cured product, comprising a curing step of curing a photocurable composition described in any one of <1> to <12> to obtain a cured product, wherein the curing step includes irradiating the photocurable composition with light. <16> The method for producing a cured product according to <15>, wherein the light is light-emitting diode light with a wavelength of 340 nm to 500 nm.

[0010] <17> The method for producing a cured product according to <15> or <16>, wherein the curing step comprises injecting the photocurable composition between a pair of molds and irradiating the photocurable composition injected between the pair of molds with light to obtain a cured product of the photocurable composition, the pair of molds being a pair of glass molds or a pair of resin molds.

[0011] According to one aspect of this disclosure, a photocurable composition and a method for producing a cured product are provided, which can yield a cured product with reduced yellowness and excellent hardness, as well as a cured product and optical material with reduced yellowness and excellent hardness.

[0012] In this disclosure, numerical ranges expressed using "~" mean a range that includes the numbers before and after "~" as the lower and upper limits. In this disclosure, the amount of each component in a composition means the total amount of multiple substances present in the composition, unless otherwise specified, if there are multiple substances corresponding to each component in the composition. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples.

[0013] In this disclosure, “light” means ultraviolet light or visible light. In this disclosure, “(meth)acrylate” means acrylate or methacrylate, “(meth)acryloyl” means acryloyl or methacryloyl, “(meth)acrylic” means acrylic or methacrylic, “iso(thio)cyanate” means isocyanate or isothiocyanate, and “iso(thio)cyanate group” means isocyanate group or isothiocyanate group.

[0014] The first and second embodiments of this disclosure will be described below. There may be overlapping portions between the first and second embodiments. For example, the photocurable composition of the first embodiment may have the characteristics of the photocurable composition of the second embodiment.

[0015] ≪First Embodiment≫

[0016] [Photocurable Composition] The photocurable composition of the first embodiment of the present disclosure contains a photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) comprises at least one selected from the group consisting of compounds represented by the following formulas (1) to (5).

[0017]

[0018] The meanings of the symbols in equations (1) to (5) will be explained later.

[0019] By irradiating the photocurable composition of the first embodiment with light, the degree of yellowness is reduced and a cured product with excellent hardness is obtained. These effects are obtained by the combination of the photobase generator (a), the polyiso(thio)cyanate compound (b), the polythiol compound (c), and the di(meth)acrylate compound (d).

[0020] In this disclosure, a cured product with excellent hardness means a cured product in which a glass transition temperature (Tg) of 50°C or higher is observed. If the hardness of the cured product is insufficient and the cured product is rubbery, a Tg of 50°C or higher will not be observed (i.e., no Tg is observed, or if observed, the Tg is less than 50°C). A preferred range for the Tg of the cured product is 60°C to 120°C, more preferably 70°C to 105°C, and even more preferably 80°C to 105°C, which is suitable from the viewpoint of hardness.

[0021] <Photobase Generator (a)> The photocurable composition of the first embodiment contains at least one photobase generator (a). Here, the photobase generator (a) is a compound that generates a base when irradiated with light. The photobase generator (a) includes at least one selected from the group consisting of compounds represented by the following formulas (1) to (5).

[0022] (The compound represented by formula (1))

[0023]

[0024] In formula (1), R １ ~R ４Each of these independently represents an alkyl group having 1 to 8 carbon atoms, R ５ ~R ８ Each of these independently represents a C1-C8 alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthrill group, and the phenyl group, naphthyl group, anthracenyl group, and phenanthrill group may be substituted with a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group.

[0025] In formula (1), R １ ~R ４ It is preferable that they are the same. １ ~R ４ It is preferably an alkyl group having 2 to 5 carbon atoms, more preferably a linear alkyl group, and even more preferably an n-butyl group.

[0026] In formula (1), R ８ R is preferably an alkyl group having 2 to 5 carbon atoms, more preferably a linear alkyl group, and even more preferably an n-butyl group. ５ ~R ７ It is preferable that they are the same. ５ ~R ７ It is preferably a phenyl group, a butylphenyl group, or a naphthyl group, and more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group, or a 4-methyl-1-naphthyl group. ５ ~R ７ If the compound contains an aromatic ring, the aromatic ring may be substituted with an alkyl group, an aryl group, or the like.

[0027] The compound represented by formula (1) is preferably at least one selected from the group consisting of tetra(n-butyl)ammonium=n-butyltriphenyl borate, tetra(n-butyl)ammonium=n-butyltri(4-tert-butylphenyl) borate, tetra(n-butyl)ammonium=n-butyltri(1-naphthyl) borate, and tetra(n-butyl)ammonium=n-butyltri(4-methyl-1-naphthyl) borate. The "=" in the compound name signifies an ionic bond.

[0028] Among the above, from the viewpoint of solubility, polymerizability and pot life balance of the composition, it is more preferable that the compound represented by formula (1) is at least one selected from the group consisting of tetra(n-butyl)ammonium=n-butyltriphenylborate and tetra(n-butyl)ammonium=n-butyltri(1-naphthyl)borate.

[0029] Specific examples of compounds represented by formula (1) include, but are not limited to, the following compounds.

[0030]

[0031] (The compound represented by formula (2))

[0032]

[0033] In formula (2), R １ ~R ７ Each of these independently represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, R ８ ~R １１ Each of these independently represents a C1-C8 alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthrill group, and the phenyl group, naphthyl group, anthracenyl group, and phenanthrill group may be substituted with a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group.

[0034] In formula (2), R ４ and R ５ It is preferably a cycloalkyl group having 3 to 8 carbon atoms, and more preferably a cycloalkyl group having 4 to 7 carbon atoms. The cycloalkyl group is preferably a cyclohexyl group. １ ~R ３ , R ６ and R ７ It is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group. １ ~R ３ , R ６ and R７ It is preferable that it be a linear alkyl group.

[0035] In formula (2), R １１ R is preferably an alkyl group having 2 to 5 carbon atoms, more preferably a linear alkyl group, and even more preferably an n-butyl group. ８ ~R １０ It is preferable that they are the same. ８ ~R １０ It is preferably a phenyl group, a butylphenyl group, or a naphthyl group, and more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group, or a 4-methyl-1-naphthyl group. ８ ~R １０ If the compound contains an aromatic ring, the aromatic ring may be substituted with an alkyl group, an aryl group, or the like.

[0036] Also, in equation (2), R ８ ~R １１ It is also preferable that they be the same. ８ ~R １１ If they are the same, R ８ ~R １１ R is preferably a phenyl group, a butylphenyl group, or a naphthyl group, and more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group, or a 4-methyl-1-naphthyl group. ８ ~R １１ If the two are the same and include an aromatic ring, the aromatic ring may be substituted with a halogen atom, an alkyl group, an aryl group, etc., and is preferably substituted with a halogen atom, and more preferably substituted with a fluorine atom.

[0037] The compound represented by formula (2) is preferably at least one selected from the group consisting of 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium=n-butyltriphenyl borate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium=tetrakis(3-fluorophenyl) borate, and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium=butyltri(1-naphthyl) borate. The "=" in the compound name signifies an ionic bond.

[0038] Among the above, from the viewpoint of solubility, polymerizability and pot life balance of the composition, it is more preferable that the compound represented by formula (2) is at least one selected from the group consisting of 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium=n-butyltriphenyl borate and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium=tetrakis(3-fluorophenyl) borate.

[0039] Specific examples of compounds represented by formula (2) include, but are not limited to, the following compounds.

[0040]

[0041] (The compound represented by formula (3))

[0042]

[0043] In equation (3), n represents an integer from 1 to 3, and R １ ~R ４ Each of these independently represents a C1-C8 alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthrill group, and the phenyl group, naphthyl group, anthracenyl group, and phenanthrill group may be substituted with a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group.

[0044] n is preferably 1 or 3.

[0045] R ４R is preferably an alkyl group having 2 to 5 carbon atoms, more preferably a linear alkyl group, and even more preferably an n-butyl group. １ ~R ３ It is preferable that they are the same. １ ~R ３ It is preferably a phenyl group, a butylphenyl group, or a naphthyl group, and more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group, or a 4-methyl-1-naphthyl group. １ ~R ３ If the compound contains an aromatic ring, the aromatic ring may be substituted with an alkyl group, an aryl group, or the like.

[0046] Also, in equation (3), R １ ~R ４ It is also preferable that they be the same. １ ~R ４ If they are the same, R １ ~R ４ R is preferably a phenyl group, a butylphenyl group, or a naphthyl group, and more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group, or a 4-methyl-1-naphthyl group. １ ~R ４ If the two are the same and include an aromatic ring, the aromatic ring may be substituted with a halogen atom, an alkyl group, an aryl group, etc., and is preferably substituted with a halogen atom, and more preferably substituted with a fluorine atom.

[0047] The compound represented by formula (3) is preferably at least one selected from the group consisting of diazabicycloundecenium = n-butyltriphenylborate, diazabicycloundecenium = tetrakis(3-fluorophenyl)borate, diazabicycloundecenium = butyltri(1-naphthyl)borate, diazabicycloundecenium = tetraphenylborate, diazabicyclononenium = n-butyltriphenylborate, diazabicyclononenium = tetrakis(3-fluorophenyl)borate, diazabicyclononenium = butyltri(1-naphthyl)borate, and diazabicyclononenium = tetraphenylborate. In the compound name, "=" means an ionic bond.

[0048] Among them, the compound represented by formula (3) is more preferably at least one selected from the group consisting of diazabicycloundecenium = tetraphenylborate and diazabicyclononenium = tetraphenylborate.

[0049] (Compound represented by formula (4))

[0050]

[0051] In formula (4), R １ ~R ４ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group.

[0052] R ４ is preferably an alkyl group having 2 to 5 carbon atoms, more preferably a linear alkyl group, and even more preferably an n-butyl group. R １ ~R ３ are preferably the same. R １ ~R ３is preferably a phenyl group, a butylphenyl group or a naphthyl group, more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group or a 4-methyl-1-naphthyl group. R １ ~R ３ When containing an aromatic ring, the aromatic ring may be substituted with an alkyl group, an aryl group or the like.

[0053] Further, in the formula (4), R １ ~R ４ are preferably the same. R １ ~R ４ When being the same, R １ ~R ４ is preferably a phenyl group, a butylphenyl group or a naphthyl group, more preferably a phenyl group, a 4-tert-butylphenyl group, a 1-naphthyl group or a 4-methyl-1-naphthyl group. R １ ~R ４ When being the same and containing an aromatic ring, the aromatic ring may be substituted with a halogen atom, an alkyl group, an aryl group or the like, preferably substituted with a halogen atom, more preferably substituted with a fluorine atom.

[0054] The compound represented by the formula (4) is preferably at least one selected from the group consisting of 1,1,3,3-tetramethylguanidinium = n-butyltriphenylborate, 1,1,3,3-tetramethylguanidinium = tetrakis(3-fluorophenyl)borate, 1,1,3,3-tetramethylguanidinium = butyltri(1-naphthyl)borate and 1,1,3,3-tetramethylguanidinium = tetraphenylborate. In the compound name, "=" means an ionic bond.

[0055] Among them, the compound represented by the formula (4) is more preferably 1,1,3,3-tetramethylguanidinium = tetraphenylborate.

[0056] (Compound represented by the formula (5))

[0057]

[0058] In formula (5), R １ n represents an aromatic hydrocarbon group which is a phenyl group, naphthyl group, anthracenyl group, or phenanthuryl group, or an unsaturated heterocyclic group which is a pyrrolyl group, furfuryl group, imidazolyl group, pyrazolyl group, oxazolyl group, thiazolyl group, triazolyl group, tetrazolyl group, pyridinium group, triazinyl group, or tetradinyl group, and the aromatic hydrocarbon group and the unsaturated heterocyclic group may each be substituted with a halogen atom, alkyl group, alkoxy group, alkylthio group, aryl group, alkenyl group, cycloalkyl group, or heterocyclic group, and may be fused with a heterocyclic ring. In formula (5), n and R ２ ~R ５ n and R in equation (3) are, respectively. １ ~R ４ It is synonymous with [the above].

[0059] R in equation (5) １ In this, a heterocyclic group with 5 to 8 members is preferred as the substituent. １ In this context, a heterocycle that may be fused with an aromatic hydrocarbon group and an unsaturated heterocyclic group is preferably a heterocycle with 5 to 8 members.

[0060] R in equation (5) １ Preferably, this is a phenyl group, naphthyl group, anthracenyl group, or phenanthyl group, which may be substituted with an alkoxy group or an alkylthio group, and may be fused with a 5-8 membered heterocycle.

[0061] R in equation (5) １ A preferred example is shown below. In this disclosure, * in the chemical formulas indicates a bond position.

[0062]

[0063] Specific examples of compounds represented by formula (5) include, but are not limited to, the following compounds. Furthermore, specific examples include structures in which the above-mentioned substituents (i.e., halogen atoms, alkyl groups, alkoxy groups, alkylthio groups, aryl groups, alkenyl groups, cycloalkyl groups, or heterocyclic groups) are added to the aromatic ring portion of the following compounds.

[0064]

[0065] In the first embodiment, the photobase generator (a) preferably uses light at 365 nm with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ This is a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 by irradiation with light at a rate of 1 / s. This further enhances the effects of the photocurable composition of the first embodiment (i.e., the effect that irradiating the photocurable composition of the first embodiment with light reduces the yellowness and yields a cured product with excellent hardness). From the viewpoint of further improving the transparency of the resulting cured product, the photobase generator (a) in the first embodiment is more preferably irradiated with 365 nm light at an integrated light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of 0 / s, or it is irradiated with light at 365 nm with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that generates an imine with a pKa of 5 to 15 by light irradiation at a rate of / s. From the viewpoint of further improving the transparency of the resulting cured product, the photobase generator (a) in the first embodiment preferably includes at least one selected from the group consisting of compounds represented by formulas (2) to (5) above.

[0066] In this first embodiment and the second embodiment described later, the pKa (acid dissociation index) of the amine or imine produced by light irradiation can be, for example, the acid dissociation index described in the Chemical Handbook (3rd revised edition, published June 25, 1984, by Maruzen Co., Ltd.) edited by the Chemical Society of Japan.

[0067] The content of the photobase generator (a) in the first embodiment is preferably 0.05% to 5% by mass, more preferably 0.05% to 3% by mass, and even more preferably 0.10% to 2% by mass, based on the total amount of the photocurable composition of the first embodiment.

[0068] <Polyiso(thio)cyanate compound (b)> The photocurable composition of the first embodiment contains at least one polyiso(thio)cyanate compound (b). Polyiso(thio)cyanate compound (b) is a compound containing two or more iso(thio)cyanate groups.

[0069] Examples of polyiso(thio)cyanate compounds (b) include aliphatic polyiso(thio)cyanate compounds, alicyclic polyiso(thio)cyanate compounds, aromatic polyiso(thio)cyanate compounds, heterocyclic polyiso(thio)cyanate compounds, etc., and one or more may be used in combination. These polyiso(thio)cyanate compounds may include dimers, trimers, and prepolymers. Examples of these polyiso(thio)cyanate compounds include those exemplified in International Publication No. 2011 / 055540. In this disclosure, an alicyclic polyiso(thio)cyanate compound refers to a polyiso(thio)cyanate compound that includes an alicyclic structure and may also include a heterocyclic structure; an aromatic polyiso(thio)cyanate compound refers to a polyiso(thio)cyanate compound that includes an aromatic structure and may also include an alicyclic structure and a heterocyclic structure; and a heterocyclic polyiso(thio)cyanate compound refers to a polyiso(thio)cyanate compound that includes a heterocyclic structure and does not include an alicyclic structure and an aromatic structure.

[0070] The polyiso(thio)cyanate compound (b) preferably includes at least one selected from the group consisting of aliphatic polyiso(thio)cyanate compounds, alicyclic polyiso(thio)cyanate compounds, aromatic polyiso(thio)cyanate compounds, and heterocyclic polyiso(thio)cyanate compounds.

[0071] The polyiso(thio)cyanate compound (b) preferably comprises at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate. More preferably, the product comprises at least one selected from the group consisting of 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, xylylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane, and even more preferably, at least one selected from the group consisting of 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, and m-xylylene diisocyanate.

[0072] <Polythiol compound (c)> The photocurable composition of the first embodiment contains at least one polythiol compound (c). When the photocurable composition of the first embodiment contains a polyiso(thio)cyanate compound (b) and a polythiol compound (c), a thiourethane resin is obtained as a cured product when the photocurable composition is cured.

[0073] Polythiol compound (c) is a compound having two or more mercapto groups. Examples of polythiol compound (c) include the compounds exemplified in International Publication No. 2016 / 125736.

[0074] The polythiol compound (c) is preferably 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(mercapto) It comprises at least one selected from the group consisting of captomethyl)-1,4-dithiane, bis(2-mercaptoethyl) sulfide, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithiethane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane, More preferably, it comprises at least one selected from the group consisting of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, pentaerythritol tetrakiss (3-mercaptopropionate), and pentaerythritol tetrakiss (2-mercaptoacetate), More preferably, the material comprises at least one selected from the group consisting of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane.

[0075] <Di(meth)acrylate compound (d)> The photocurable composition of the first embodiment contains at least one di(meth)acrylate compound (d). Di(meth)acrylate compound (d) is a compound having two (meth)acryloyl groups. As described above, di(meth)acrylate compound (d) contributes to reducing the yellowness of the resulting cured product. The photocurable composition of the first embodiment is considered to have superior hardness of the cured product compared to the case in which a mono(meth)acrylate compound is contained instead of di(meth)acrylate compound (d) due to the inclusion of di(meth)acrylate compound (d). The photocurable composition of the first embodiment is considered to have superior compatibility of each component in the photocurable composition compared to the case in which a trifunctional or more (meth)acrylate compound is contained instead of di(meth)acrylate compound (d) due to the inclusion of di(meth)acrylate compound (d).

[0076] The molecular weight of the di(meth)acrylate compound (d) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less. The lower limit of the molecular weight of the di(meth)acrylate compound (d) is, for example, 200.

[0077] Examples of di(meth)acrylate compounds (d) include neopentyl di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. Examples include acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropoxy)phenyl]propane, ethylene oxide-modified bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, and the like.

[0078] The di(meth)acrylate compound (d) preferably contains a tricyclodecane structure. This reduces surface unevenness and retardation of the resulting cured product. Retardation is the amount obtained by multiplying the in-plane birefringence ΔNxy (= |nx - ny|) by the thickness d of the cured product. Here, nx and ny are the refractive indices in the slow phase axis and the fast phase axis, respectively.

[0079] The di(meth)acrylate compound (d) is preferably at least one of tricyclodecanedimethanol diacrylate and tricyclodecanedimethanol dimethacrylate. This reduces surface unevenness and retardation of the resulting cured product.

[0080] In the photocurable composition of the first embodiment, the total amount of the polyiso(thio)cyanate compound (b), the polythiol compound (c), and the di(meth)acrylate compound (d) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more, based on the total amount of the photocurable composition.

[0081] In the photocurable composition of the first embodiment, when the amount of mercapto groups in the polythiol compound (c) (hereinafter also referred to as (cm)) is set to 100 mol%, the sum of the amount of iso(thio)cyanato groups in the polyiso(thio)cyanate compound (b) (hereinafter also referred to as (bm)) and the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) (hereinafter also referred to as (dm)) is preferably 70 mol% to 130 mol%, more preferably 80 mol% to 120 mol%, and even more preferably 90 mol% to 110 mol%.

[0082] In the photocurable composition of the first embodiment, when the sum of the amount of iso(thio)cyanate groups (bm) in the polyiso(thio)cyanate compound (b) and the amount of (meth)acryloyl groups (dm) in the di(meth)acrylate compound (d) is taken as 100 mol%, the amount of (meth)acryloyl groups (dm) in the di(meth)acrylate compound (d) is preferably 1 mol% to 60 mol%, more preferably 5 mol% to 50 mol%, and even more preferably 10 mol% to 40 mol%.

[0083] <UV absorber> The photocurable composition of the first embodiment may contain at least one UV absorber.

[0084] As the ultraviolet absorber, at least one selected from the group consisting of compounds represented by the following formulas (e-1) to (e-4) is preferred.

[0085]

[0086] In formula (e-1), R １ represents a hydrogen atom or a chlorine atom, R ２ and R ３Each of these independently represents a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or an aromatic or heteroaromatic group having 4 to 12 carbon atoms. When a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms contains substituents, examples of substituents include aromatic or heteroaromatic groups having 6 to 12 carbon atoms. Examples of aromatic and heteroaromatic groups include phenyl group, biphenyl group, 2,3,5-trimethylphenyl group, furyl group, p-methoxyphenyl group, etc. Commercially available compounds may be used as the compound represented by formula (e-1), for example, Tinuvin 234 (manufactured by BASF Japan Ltd.), Tinuvin 328 (manufactured by BASF Japan Ltd.), etc.

[0087] In formula (e-2), A １ This represents the structure shown by the following formula (e-2a), and R ４ and R ５ Each of these independently represents a structure expressed by the following formula (e-2b).

[0088]

[0089] In equations (e-2a) and (e-2b), Q １ ~Q ５ Each of these independently represents a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a halogen, or an aromatic or heteroaromatic group having 4 to 12 carbon atoms. In the linear or branched alkyl group having 1 to 12 carbon atoms, the number of carbon atoms is preferably 1 to 6, and more preferably 1 to 3. Examples of linear or branched alkoxy groups having 1 to 18 carbon atoms include methoxy, butoxy, 2-hydroxy-3-octyloxy-propyroxy, and 2-ethylhexyloxy. Examples of aromatic and heteroaromatic groups include phenyl, biphenyl, 2,3,5-trimethylphenyl, furyl, and p-methoxyphenyl. Commercially available compounds may be used as the compound represented by formula (e-2), such as Tinuvin 405 (manufactured by BASF Japan Ltd.) and Tinuvin 1600 (manufactured by BASF Japan Ltd.).

[0090] In formula (e-3), R ６ and R ７ Each of these independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Examples of linear or branched alkyl groups having 1 to 6 carbon atoms in formula (e-3) include methyl, ethyl, butyl, propyl, pentyl, and hexyl groups. Examples of linear or branched alkoxy groups having 1 to 6 carbon atoms include methoxy, ethoxy, butoxy, and phenoxy groups. Commercially available compounds may be used as the compounds represented by formula (e-3), such as Hostavin VSU (manufactured by Clariant Chemicals Co., Ltd.).

[0091] In formula (e-4), R ８ R represents an aromatic group having 6 to 20 carbon atoms, which may be substituted, or an alicyclic group having 5 to 20 carbon atoms, which may be substituted. ９ and R １０ Each of these independently represents a linear or branched alkyl group having 1 to 6 carbon atoms. Examples of aromatic groups having 6 to 20 carbon atoms that may be substituted include phenyl, benzyl, benzoyl, and p-methoxybenzyl groups. Examples of alicyclic groups having 5 to 20 carbon atoms that may be substituted include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopentanyl, and cyclodecanyl groups. If the aromatic group or alicyclic group contains a substituent, examples of substituents include alkyl groups having 1 to 6 carbon atoms and alkoxy groups having 1 to 6 carbon atoms. A commercially available compound may be used as the compound represented by formula (e-4), for example, Hostavin PR25 (manufactured by Clariant Chemicals Co., Ltd.).

[0092] If the photocurable composition of the first embodiment contains an ultraviolet absorber, its content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.10% by mass or more, based on the total amount of the photocurable composition. The upper limit of the ultraviolet absorber content relative to the total amount of the photocurable composition is preferably 3.00% by mass or less, more preferably 2.00% by mass or less, and even more preferably 1.00 part by mass or less.

[0093] <Release Agent> The photocurable composition of the first embodiment may contain at least one release agent. Examples of release agents include silicone compounds and phosphate ester compounds. Examples of silicone compounds as release agents include the polyether-modified silicone compounds described in paragraphs 0195 to 0210 of International Publication No. 2023 / 063398. Examples of phosphate ester compounds as release agents include acidic phosphate esters. Examples of acidic phosphate esters include phosphate monoesters and phosphate diesters, each of which can be used alone or in combination of two or more. Examples of commercially available phosphate ester compounds as release agents include "ZELEC UN" (an acidic phosphate ester release agent manufactured by Stepan).

[0094] The photocurable composition of the first embodiment may not contain a release agent, or if it does, the content of the release agent may be 0.30% by mass or less of the total amount of the photocurable composition. If the photocurable composition of the first embodiment contains a release agent, the lower limit of the content is preferably 0.01% by mass, more preferably 0.05% by mass, of the total amount of the photocurable composition.

[0095] <Metal Catalyst> The photocurable composition of the first embodiment may contain at least one metal catalyst. The metal catalyst preferably contains tin, zinc, bismuth, aluminum, or zirconium, and more preferably contains tin. Examples of tin-containing metal catalysts include dibutyltin(IV) dilaurate, dibutyltin(IV) dichloride, and dimethyltin(IV) dichloride.

[0096] The photocurable composition of the first embodiment may not contain a metal catalyst (for example, a metal catalyst containing tin), or if it does, the amount of the metal catalyst (for example, a metal catalyst containing tin) may be 0.05% by mass or less of the total amount of the photocurable composition.

[0097] <Other Components> The photocurable composition of the first embodiment may contain other components besides those described above, as necessary. Other components can be, for example, the components in the photocurable composition described in International Publication No. 2023 / 063398. Other components include, for example, photosensitizers, episulfide compounds, epoxy group compounds, phenol compounds, amino group compounds, inorganic compounds having sulfur atoms, inorganic compounds having selenium atoms, solvents, bluing agents, IR cutters, blue light cutters, reactive diluents, oil-soluble dyes, pigments, fragrances, fillers, adhesion improvers (e.g., coupling agents), chain extenders, crosslinking agents, defoamers, anti-settling agents, dispersants, plasticizers, anti-sagging agents, antifouling agents, Examples of ingredients include preservatives, bactericides, antimicrobial agents, antifungal agents, matting agents, thickeners, pigment dispersants, anti-repellent agents, scratch-resistant agents, slip agents, surface modifiers, color separation inhibitors, emulsifiers, anti-skinning agents, drying agents, anti-fouling agents, antistatic agents, conductive agents (electrostatic additives), flame retardants, thermal conductivity modifiers, plasticizers, silica microparticles, zirconium oxide microparticles, titanium oxide microparticles, zinc oxide microparticles, silver oxide microparticles, polyolefin microparticles, poly(meth)acrylic microparticles, polyurethane microparticles, etc. Furthermore, other components may be referenced from the components in the photocurable composition described in International Publication No. 2023 / 063398.

[0098] <Light> The light (i.e., ultraviolet light or visible light) used to cure the photocurable composition of the first embodiment preferably includes light with a wavelength of 340 nm to 500 nm. Examples of light sources for irradiation include sunlight, chemical lamps, mercury lamps, metal halide lamps, light-emitting diode (LED) lamps, etc.

[0099] The photocurable composition of the first embodiment is preferably used in the production of cured products by irradiation with light-emitting diode light having a wavelength of 340 nm to 500 nm.

[0100] [Cured Product] The cured product of the first embodiment is a cured product of the photocurable composition of the first embodiment described above. Therefore, the cured product of the first embodiment has suppressed yellowness and excellent hardness. The cured product of the first embodiment is manufactured by irradiating the photocurable composition of the first embodiment described above with light and curing it.

[0101] From the viewpoint of curability, the thickness of the cured product of the first embodiment is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. Furthermore, the thickness of the cured product of the first embodiment is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.1 μm or more.

[0102] The refractive index of the cured product of the first embodiment is preferably 1.60 to 1.80 at 20°C and under sodium D-line light (i.e., light with a wavelength of 589.3 nm).

[0103] [Optical Materials] The optical component of the first embodiment includes the cured product of the first embodiment. The cured product of the first embodiment has suppressed yellowing and excellent hardness, making it suitable for use as an optical component. Specific examples of optical components include, for example, optical adhesives, coatings, optical waveguides, films, lenses, anti-reflective coatings, microlenses, microlens arrays, wafer-level lenses, imaging lenses for cameras (automotive cameras, digital cameras, PC cameras, mobile phone cameras, surveillance cameras, etc.), spectacle lenses, light beam focusing lenses, light diffusion lenses, camera flash lenses, etc.

[0104] [Method for Manufacturing Cured Products] The method for manufacturing cured products of the first embodiment includes a curing step of curing the photocurable composition of the first embodiment described above to obtain cured products, and the curing step includes irradiating the photocurable composition with light. By irradiating the photocurable composition of the first embodiment with light, a base is generated from the photobase generator (a), and the generated base causes polymerization of polymerizable compounds, namely polyiso(thio)cyanate compound (b), polythiol compound (c), and di(meth)acrylate compound (d). This yields cured products of the photocurable composition.

[0105] As described above, a preferred form of light (i.e., ultraviolet or visible light) used to irradiate the photocurable composition of the first embodiment for curing is light-emitting diode light with a wavelength of 340 nm to 500 nm. The light may be irradiated directly onto the photocurable composition of the first embodiment, or it may be irradiated through an object that is transparent to light (such as a mold).

[0106] The light irradiation intensity is, for example, 0.1 mW / cm². ２ / sec ~ 1000mW / cm ２ It is per second. The integrated light intensity is, for example, 10 mJ / cm². ２ ~30000mJ / cm ２ The light irradiation time is, for example, between 0.1 seconds and 1000 seconds.

[0107] The curing process includes injecting a photocurable composition between a pair of molds, and irradiating the photocurable composition injected between the pair of molds with light to obtain a cured product of the photocurable composition, wherein the pair of molds is preferably a pair of glass molds or a pair of resin molds. From the viewpoint of easily producing a cured product having fine irregularities on its surface, a pair of resin molds is preferred as the pair of molds. In particular, a pair of resin molds easily forms fine irregularities on its surface. When fine irregularities are formed on the surface of a pair of resin molds, the irregularities are transferred to the resulting cured product. This results in a cured product having fine irregularities on its surface. A cured product having fine irregularities on its surface is suitable as an optical waveguide.

[0108] The curing step may include heating the photocurable composition of the first embodiment. The heating may be performed simultaneously with, before, or after the irradiation of light. The heating conditions are not particularly limited. The heating temperature may be selected from, for example, 20°C to 200°C, and the heating time may be selected from 0.1 hours to 80 hours.

[0109] From the viewpoint of relieving internal stress generated in the cured product during curing, the curing process may include annealing the cured product. The conditions for the annealing treatment are not particularly limited. For example, the treatment temperature may be selected from 50°C to 150°C, preferably 70°C to 140°C, and more preferably 80°C to 130°C.

[0110] The curing step may include polymerizing a portion of the polymerizable compounds (i.e., polyiso(thio)cyanate compound (b), polythiol compound (c), and di(meth)acrylate compound (d)) in the photocurable composition of the first embodiment to obtain a prepolymer before irradiating the photocurable composition of the first embodiment with light. In this case, the photocurable composition containing the prepolymer is irradiated with light. This results in a better shape for the resulting cured product. The prepolymer can be formed by heating the photocurable composition of the first embodiment before irradiating with light.

[0111] ≪Second Embodiment≫

[0112] [Photocurable Composition] The photocurable composition of the second embodiment of the present disclosure contains a photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) generates light at 365 nm with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ This is a photocurable composition that is a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 upon irradiation with light at a rate of / s.

[0113] By irradiating the photocurable composition of the second embodiment with light, the degree of yellowness is reduced and a cured product with excellent hardness is obtained. These effects are obtained by the combination of the photobase generator (a), the polyiso(thio)cyanate compound (b), the polythiol compound (c), and the di(meth)acrylate compound (d). Specifically, because the photobase generator (a) is the above-mentioned quaternary ammonium salt or the above-mentioned quaternary iminium salt, when the photocurable composition of the second embodiment is irradiated with light, the reaction between the polyiso(thio)cyanate compound (b), the polythiol compound (c), and the di(meth)acrylate compound (d) proceeds effectively, resulting in a cured product with reduced yellowness and excellent hardness.

[0114] The photocurable composition of the second embodiment is the same as the photocurable composition of the first embodiment, except that the photobase generator (a) is limited to the above-mentioned quaternary ammonium salt or quaternary iminium salt, and the preferred embodiments are also the same.

[0115] In the second embodiment, the photobase generator (a) is preferably the photobase generator (a) in the first embodiment (i.e., a photobase generator comprising at least one compound selected from the group consisting of compounds represented by formulas (1) to (5)). The preferred embodiment of the photobase generator (a) in the second embodiment is the same as the preferred embodiment of the photobase generator (a) in the first embodiment.

[0116] [Cured Product] The cured product of the second embodiment of this disclosure differs from the cured product of the first embodiment, which is a cured product of the photocurable episulfide composition of the first embodiment, in that it is a cured product of the photocurable episulfide composition of the second embodiment described above. Except for this point, the cured product of the second embodiment is the same as the cured product of the first embodiment, and the preferred embodiments are also the same.

[0117] [Laminate] The laminate of the second embodiment of this disclosure differs from the laminate of the first embodiment, which includes the cured product of the second embodiment and a substrate, in that it includes the cured product of the second embodiment described above and a substrate. Except for this point, the laminate of the second embodiment is the same as the laminate of the first embodiment, and the preferred embodiments are also the same.

[0118] [Method for Manufacturing Cured Products] The method for manufacturing cured products of the second embodiment of this disclosure differs from the method for manufacturing cured products of the first embodiment, which involves irradiating the photocurable composition of the first embodiment with ultraviolet light or visible light, in that it includes irradiating the photocurable composition of the second embodiment described above with ultraviolet light or visible light to obtain a cured product of the photocurable composition of the second embodiment. Except for this point, the method for manufacturing cured products of the second embodiment is the same as the method for manufacturing cured products of the first embodiment, and the preferred embodiments are also the same.

[0119] The following are examples of the embodiments of this disclosure, but this disclosure is not limited to these embodiments.

[0120] [Examples 1-6, Comparative Examples 1-3] <Preparation of Photocurable Compositions> Photocurable compositions having the compositions shown in Table 1 were prepared. In Table 1, "-" means that the corresponding component is not contained. The amounts of the photobase generator (a) and the release agent are both expressed as mass % relative to the total amount of the photocurable composition. The total amount of the photocurable composition is the sum of the photobase generator (a), polyiso(thio)cyanate compound (b), polythiol compound (c), di(meth)acrylate compound (d), and release agent (100 mass%). The polyiso(thio)cyanate compound (b), polythiol compound (c), and di(meth)acrylate compound (d) were charged in ratios such that the sum of (bm) and (dm) when (cm) is set to 100 mol%, and the sum of (dm) when the sum of (bm) and (dm) is set to 100 mol%, are the values ​​shown in Table 1.

[0121] The details of each component in Table 1 are as follows:

[0122] (Photobase generator (a)) • (a1): Tetrabutylammonium butyltrinaphthylborate • (a2): 1-(2-([1,1'-biphenyl]-4-yl)-2-oxoethyl)-2,3,4,6,7,8-hexahydro-1H-pyrrolo[1,2-a]pyrimidine-5-ium=triphenylbutylborate • (a3): 1-(2-(naphthalene-2-yl)-2-oxoethyl)-2,3,4,6,7,8-hexahydro-1H-pyrrolo[1,2-a]pyrimidine-5-ium=triphenylbutylborate • (a4): 1-(2-(6-methoxynaphthalene-2-yl)-2-oxoethyl)-2,3,4,6,7,8-hexahydro-1H-pyrrolo[1,2-a]pyrimidine-5-ium=triphenylbutylborate The structure of (a1) to (a4) is as follows:

[0123]

[0124] (a1) uses 365 nm light with an integrated luminous intensity of 720 mJ / cm². ２ (a2) is a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 by light irradiation at a rate of 1 / s (hereinafter referred to as "light irradiation A"). (a3) ​​is a quaternary iminium salt that generates 1,5-diazabicyclo[4.3.0]nonane-5-ene (hereinafter referred to as DBN) (imine) with a pKa of 12 (in DMSO) by light irradiation A. (a4) is a quaternary iminium salt that generates DBN with a pKa of 12 (in DMSO) by light irradiation A.

[0125] Here, the pKa (acid dissociation index) can be obtained, for example, from the acid dissociation index listed in the Chemical Handbook (3rd revised edition, June 25, 1984, published by Maruzen Co., Ltd.) compiled by the Chemical Society of Japan.

[0126] (Comparative compound (thermobase generator) to photobase generator (a)) (DABCO): 1,4-diazabicyclo[2.2.2]octane

[0127] (Polyiso(thio)cyanate compound (b)) ・(b1): A mixture of 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane and 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane

[0128] (Polythiol compound (c)) • (c1): 4-mercapto-1,8-dimercapto-3,6-dithiaoctane • (c2): At least one selected from the group consisting of 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane

[0129] (Di(meth)acrylate compound (d)) ・(d1): Bisphenol A ethoxylate dimethacrylate (m+n=approx.4) (molecular weight 541)

[0130]

[0131] • (d2): Pentaerythritol triacrylate (molecular weight 298)

[0132]

[0133] • (d3): Tricyclo[5.2.1.0 ２，６ Decandimethanol diacrylate (molecular weight 304)

[0134]

[0135] • (d4): Tricyclo[5.2.1.0 ２，６ Decandimethanol dimethacrylate (molecular weight 332)

[0136]

[0137] (Release agent) ・KF-640: Polyether-modified silicone oil KF-640 manufactured by Shin-Etsu Chemical Co., Ltd. ・JP-506H: Phosphate ester compound JP-506H manufactured by Johoku Chemical Co., Ltd.

[0138] <Manufacturing of Cured Products> The photocurable composition obtained above was injected between a pair of glass molds placed 2 mm apart. Each of the pair of glass molds was a glass plate (manufactured by Topcon Optonexus) with a diameter of 76 mm and a thickness of 5 mm. The pair of glass molds into which the photocurable composition was injected were subjected to a photocuring test from both sides, with an intensity of 4 mW / cm on one side. ２ / s, irradiation time 180 seconds, and integrated light intensity 720 mJ / cm² ２ The cured material was obtained by irradiating it with light under the light irradiation conditions of mW / s, and then heating it in an oven at 120°C for 1 hour. The obtained cured material was released from a pair of glass molds to obtain a flat cured material with a diameter of 76 mm and a thickness of approximately 2 mm. In all examples, the cured material could be released from the pair of glass molds without damaging its appearance. In Table 1, in the "Removal from Mold" column, OK means that the material could be removed, and NG means that it could not be removed. Here, the light intensity (mW / cm²) under the light irradiation conditions is given. ２ The value (mJ / cm²) represents the light intensity on one side, and is the integrated light quantity (mJ / cm²). ２ The value ( / s) is obtained by multiplying the light intensity on one side by the irradiation time. As the LED light, an iGraphic 365nm 330mm square UV-LED irradiator was used.

[0139] <Evaluation of the cured material> The following evaluations were performed on the obtained cured material. The results are shown in Table 1.

[0140] (Surface unevenness) The obtained cured material was placed 400 mm away from a high-pressure mercury lamp (Optical Module X manufactured by Ushio Corporation), and the projected area of ​​the cured material displayed on a screen installed behind it was visually inspected. Surface unevenness was evaluated according to the following evaluation criteria. - Evaluation criteria for surface unevenness - A: Almost no shadows or distortions B: Shadows or distortions were partially observed C: Shadows or distortions were observed throughout

[0141] (Retardation (12.5 mm from the center)) The retardation of the obtained cured material was measured using a strain analyzer (LuCeo LSM-9001) as the average value of the deviation of 590 nm incident light in a range of 12.5 mm from the center of the obtained cured material. -Evaluation criteria for retardation (12.5 mm from the center)- A. Retardation is less than 5 nm B. Retardation is 5 nm or more and less than 10 nm C. Retardation is 10 nm or more

[0142] (Retardation (25 mm from the center)) The retardation of the obtained cured material was measured using a strain analyzer (LuCeo LSM-9001) as the average value of the deviation of 590 nm incident light in a range of 25 mm from the center of the obtained cured material. -Evaluation criteria for retardation (25 mm from the center)- A2 Retardation is less than 5 nm B2 Retardation is 5 nm or more and less than 10 nm C2 Retardation is 10 nm or more

[0143] (Yellowness) The yellowness (YI (Yellow Index)) of the obtained cured product was measured using a Konica Minolta CM-5 spectrophotometer. Based on the obtained results, the yellowness was evaluated according to the following evaluation criteria. In the following evaluation criteria, the rank that best suppresses yellowness is "A". -Evaluation Criteria for Yellowness- A... YI was 2.0 or less. B... YI was greater than 2.0 and 4.0 or less. C... YI was greater than 4.0.

[0144] (Glass transition temperature (Tg), hardness) The hardness of the obtained cured material was evaluated using whether or not a glass transition temperature (Tg) was observed as an indicator. The glass transition temperature (Tg) was measured using a Shimadzu TMA-60 thermomechanical analyzer by the TMA penetration method (50g load, pin tip 0.5mmφ, heating rate 10℃ / min). Based on the measurement results, the hardness was evaluated according to the following evaluation criteria. In the following evaluation criteria, "A" is harder than "B". -Hardness evaluation criteria- A... A Tg of 50℃ or higher was observed. B... The material hardened into a rubbery substance, and a Tg of 50℃ or higher was not observed.

[0145]

[0146] As shown in Table 1, the photocurable compositions of each example, containing a specific photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), yielded cured products with reduced yellowness and excellent hardness. For each example, the compositions of Comparative Examples 1 and 2, which did not contain the di(meth)acrylate compound (d), resulted in cured products with high yellowness. Furthermore, the composition of Comparative Example 3, which did not contain the polyiso(thio)cyanate compound (b), resulted in cured products with insufficient hardness. Specifically, the cured product became rubbery, and a Tg of 50°C or higher was not observed.

[0147] [Examples 7-10] The same procedure as in Example 1 was followed, except that a photocurable composition having the composition shown in Table 2 was used, and the pair of glass molds were replaced with the pair of resin molds shown in Table 2. The results are shown in Table 2.

[0148] The pair of resin molds used in Example 7 (labeled "PC" in Table 2) are a pair of polycarbonate molds (IWATA Polycarbonate Sheet (Transparent) POP-100-100-1, 1 mm thick, 86% light transmittance at 365 nm). The pair of resin molds used in Example 8 (labeled "TPX" in Table 2) are a pair of 4-methyl-1-pentene resin molds (TPX, manufactured by Mitsui Chemicals, 5 mm thick, 3% light transmittance at 365 nm). The pair of resin molds used in Examples 9 and 10 are a pair of acrylic resin molds (Hikari Co., Ltd. Acrylic Disc AE128, 5 mm thick, 3% light transmittance at 365 nm).

[0149] [Examples 11-13] The same procedure as in Example 1 was followed, except that a photocurable composition having the composition shown in Table 2 was used. The results are shown in Table 2.

[0150] [Comparative Example 4] A comparative curable composition (specifically, a thermosetting composition) having the composition shown in Table 2 was used; a pair of glass molds was replaced with a pair of resin molds shown in Table 2 (in Table 2, "PC"; a pair of polycarbonate molds (IWATA polycarbonate sheet (transparent) POPC-100-100-1, 1 mm thick, 365 nm light transmittance 86%)); and the curing method (specifically light irradiation and heating) in the production of the cured product was changed to heating under conditions of raising the temperature from 25°C to 120°C over 20 hours (i.e., no light irradiation). The production of a cured product was attempted in the same manner as in Example 1, except that the cured product adhered to the resin mold after heating and could not be demolded. In other words, demolding from the mold was not possible (see Table 2). Therefore, the evaluation of the cured product was omitted.

[0151] [Comparative Example 5] A comparative curable composition (specifically, a thermosetting composition) having the composition shown in Table 2 was used; a pair of glass molds was changed to a pair of resin molds shown in Table 2 (in Table 2, "acrylic"; a pair of acrylic resin molds (Hikari Co., Ltd. acrylic disc AE128, 5 mm thick, 3% light transmittance at 365 nm)); and the curing method (specifically, light irradiation and heating) in the production of the cured product was changed to heating under conditions of raising the temperature from 25°C to 120°C over 20 hours (i.e., no light irradiation). The production of a cured product was attempted in the same manner as in Example 1, except that a comparative curable composition (specifically, a thermosetting composition) having the composition shown in Table 2 was used; a pair of glass molds was changed to a pair of resin molds (specifically, "acrylic" in Table 2); and the cured product was changed to heating under conditions of raising the temperature from 25°C to 120°C over 20 hours (i.e., no light irradiation). As a result, after heating, the cured product was able to adhere to the resin mold and be demolded. That is, demolding from the mold was OK (see Table 2). However, distortion and appearance defects were observed in the obtained cured product. Therefore, the evaluation of the cured product was omitted.

[0152] The meanings of the abbreviations in Table 2 are the same as those in Table 1. In Comparative Examples 4 and 5, the following release agents were used: JP-506H: A phosphate ester compound manufactured by Johoku Chemical Co., Ltd.

[0153]

[0154] As shown in Table 1, the photocurable compositions of each example, each containing a specific photobase generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), yielded cured products with reduced yellowness and excellent hardness, regardless of whether a glass mold or a resin mold was used. In Comparative Example 4, where a comparative curable composition containing a comparative compound (DABCO) was used instead of the specific photobase generator (a) for each example, and a resin mold (PC) was used, the cured product could not be released. In Comparative Example 5, where a comparative curable composition containing a comparative compound (DABCO) was used instead of the specific photobase generator (a), and a resin mold (acrylic) was used, the cured product could be released, but distortion and poor appearance were observed in the resulting cured product, so evaluation was omitted.

[0155] The disclosures of Japanese Patent Application No. 2024-230808, filed on 26 December 2024, and Japanese Patent Application No. 2025-197700, filed on 18 November 2025, are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A photocurable composition containing a photo-base generator (a), a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photo-base generator (a) contains at least one selected from the group consisting of compounds represented by the following formula (1) to the following formula (5). [In formula (1), R １ to R ４ each independently represents an alkyl group having 1 to 8 carbon atoms, and R ５ to R ８ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (2), R １ to R ７ each independently represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, and R ８ to R １１ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (3), n represents an integer of 1 to 3, and R １ to R ４ each independently represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthryl group, and the phenyl group, the naphthyl group, the anthracenyl group, and the phenanthryl group may be substituted by a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (4), R １ to R ４ Each of these independently represents a C1-C8 alkyl group, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthrill group, and the phenyl group, naphthyl group, anthracenyl group, and phenanthrill group may be substituted with a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, or a heterocyclic group. In formula (5), R １ n represents an aromatic hydrocarbon group which is a phenyl group, naphthyl group, anthracenyl group, or phenanthuryl group, or an unsaturated heterocyclic group which is a pyrrolyl group, furfuryl group, imidazolyl group, pyrazolyl group, oxazolyl group, thiazolyl group, triazolyl group, tetrazolyl group, pyridinium group, triazinyl group, or tetradinyl group, and the aromatic hydrocarbon group and the unsaturated heterocyclic group may each be substituted with a halogen atom, alkyl group, alkoxy group, alkylthio group, aryl group, alkenyl group, cycloalkyl group, or heterocyclic group, and may be fused with a heterocyclic ring. In formula (5), n and R ２ ~R ５ n and R in equation (3) are, respectively. １ ~R ４ This is synonymous with [the above].

2. The photobase generator (a) generates light at 365 nm, accumulating to a total light intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ The photocurable composition according to claim 1, which is a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 by irradiation with light at a rate of / s.

3. The photobase generator (a) contains a polyiso(thio)cyanate compound (b), a polythiol compound (c), and a di(meth)acrylate compound (d), wherein the photobase generator (a) generates light at 365 nm with an integrated luminous intensity of 720 mJ / cm². ２ It is a quaternary ammonium salt that produces an amine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ It is a quaternary iminium salt that produces an imine with a pKa of 5 to 15 upon irradiation with light at a rate of / s, or it is a 365 nm light with an integrated light intensity of 720 mJ / cm². ２ A photocurable composition comprising a quaternary ammonium salt that generates an aryl anion with a pKa of 35 to 40 upon irradiation with light at a rate of / s.

4. The photocurable composition according to claim 1 or claim 3, wherein the molecular weight of the di(meth)acrylate compound (d) is 1000 or less.

5. The photocurable composition according to claim 1 or claim 3, wherein the di(meth)acrylate compound (d) comprises a tricyclodecane structure.

6. The photocurable composition according to claim 1 or claim 3, wherein the di(meth)acrylate compound (d) is at least one of tricyclodecanedimethanol diacrylate and tricyclodecanedimethanol dimethacrylate.

7. The photocurable composition according to claim 1 or claim 3, wherein the content of the photobase generator (a) is 0.05% by mass to 5% by mass based on the total amount of the photocurable composition.

8. The photocurable composition according to claim 1 or claim 3, wherein, when the amount of mercapto groups in the polythiol compound (c) is taken as 100 mol%, the sum of the amount of iso(thio)cyanate groups in the polyiso(thio)cyanate compound (b) and the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is 70 mol% to 130 mol%.

9. The photocurable composition according to claim 1 or claim 3, wherein when the sum of the amount of iso(thio)cyanate groups in the polyiso(thio)cyanate compound (b) and the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is 100 mol%, the amount of (meth)acryloyl groups in the di(meth)acrylate compound (d) is 1 mol% to 60 mol%.

10. The photocurable composition according to claim 1 or claim 3, wherein the polyiso(thio)cyanate compound (b) comprises at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate.

11. The polythiol compound (c) is 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(mercaptomethyl A photocurable composition according to claim 1 or claim 3, comprising at least one selected from the group consisting of )-1,4-dithiane, bis(2-mercaptoethyl)sulfide, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithiethane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane.

12. A photocurable composition according to claim 1 or claim 3, used for producing a cured product by irradiation with light-emitting diode light having a wavelength of 340 nm to 500 nm.

13. A cured product of the photocurable composition according to claim 1 or claim 3.

14. An optical material comprising the cured product described in claim 13.

15. A method for producing a cured product, comprising a curing step of curing a photocurable composition according to claim 1 or claim 3 to obtain a cured product, wherein the curing step includes irradiating the photocurable composition with light.

16. The method for producing a cured product according to claim 15, wherein the light is light-emitting diode light with a wavelength of 340 nm to 500 nm.

17. The method for producing a cured product according to claim 15, wherein the curing step comprises: injecting the photocurable composition between a pair of molds; and irradiating the photocurable composition injected between the pair of molds with light to obtain a cured product of the photocurable composition, wherein the pair of molds is a pair of glass molds or a pair of resin molds.

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