Photocurable composition for photoelectric fusion device, member for photoelectric fusion device, and photoelectric fusion device

Abstract

A photocurable composition for a photoelectric fusion device contains: a polymerizable compound containing a (meth) acryloyl group; and a photopolymerization initiator, in which the content of the photopolymerization initiator is 0.5 mass% or less with respect to the total amount of the polymerizable compound containing a (meth) acryloyl group.

Description

Photocurable composition for photoelectric fusion devices, components for photoelectric fusion devices, and photoelectric fusion devices

[0001] This disclosure relates to a photocurable composition for photoelectric fusion devices, a component for photoelectric fusion devices, and a photoelectric fusion device.

[0002] In recent years, with the increase in generative AI and LLM (Large-Scale Language Models), there has been a growing demand for higher bandwidth capabilities and reduced power consumption in data centers. Optoelectronic devices are attracting attention as devices that can achieve these goals. Various studies have been conducted on technologies related to optoelectronic devices (for example, polymer optical waveguides, which are one element of optoelectronic devices).

[0003] For example, Patent Document 1 discloses the following composition for manufacturing optical materials such as polymer optical waveguides that are excellent in high transparency (low propagation loss), heat resistance, solder reflow resistance, and high adhesion to the substrate. The composition disclosed in Patent Document 1 is an optical material composition containing a polymer having a specific silsesquioxane skeleton in the polymer main chain, and the polymer main chain being silicone. Furthermore, Patent Document 2 discloses the following composition as a photocurable composition for optical materials that is soluble in an alkaline aqueous solution, has excellent transparency at a wavelength of 850 nm and excellent light propagation, and the cured product has excellent adhesion between the core and cladding and adhesion to the substrate. The composition disclosed in Patent Document 2 is a photocurable composition for optical materials containing (A) a polyurethane compound having one or more acidic groups and ethylenically unsaturated bonds in its molecule, (B) a polymerizable compound, and (C) a polymerization initiator, wherein the polymerizable compound (B) contains both (B1) a polymerizable compound having an alicyclic structure in its molecule and (B2) a polymerizable compound having an aromatic ring structure in its molecule. Furthermore, Patent Document 3 discloses the following composition as a photocurable composition for optical materials that has a high refractive index, excellent transparency and light propagation at a wavelength of 850 nm, is soluble in alkaline aqueous solutions, and exhibits good processability and size controllability. The composition disclosed in Patent Document 3 is a photocurable composition for optical materials containing (A) an acidic group-containing polyester resin having a fluorene skeleton in its main chain, (B) a polymerizable compound, and (C) a polymerization initiator, wherein the polyester resin (A) is a compound having two or more ethylenically unsaturated groups in its molecule. Furthermore, Patent Document 4 discloses the following photocurable composition for optical waveguide formation, which is particularly useful for resin films for optical waveguide formation that have excellent transparency, reflow heat resistance and thermal stability, enable high-precision thick film formation and alkaline development, and have high productivity. The composition disclosed in Patent Document 4 is a photocurable composition for optical waveguide formation comprising (A) a polymer having a carboxyl group, (B) (meth)acrylate, (C) a photoradical polymerization initiator, and (D) a phenolic antioxidant.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2024-123795 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2018-48277 Patent Document 3: Japanese Unexamined Patent Application Publication No. 2016-199720 Patent Document 4: Japanese Unexamined Patent Application Publication No. 2012-133237

[0005] However, there may be a case where it is required to further improve the resolution (i.e., accuracy) of the cured product obtained by the photocurable composition for an optoelectronic fusion device. An object of one aspect of the present disclosure is to provide a photocurable composition for an optoelectronic fusion device that can produce a cured product with excellent resolution, and a member for an optoelectronic fusion device and an optoelectronic fusion device that can be produced using this photocurable composition for an optoelectronic fusion device.

[0006] Means for solving the above problems include the following aspects.<1> A photocurable composition for an optoelectronic fusion device, containing a polymerizable compound containing a (meth)acryloyl group and a photopolymerization initiator, wherein the content of the photopolymerization initiator is 0.5% by mass or less based on the total amount of the polymerizable compound containing the (meth)acryloyl group.<2> The photocurable composition for an optoelectronic fusion device according to <1>, wherein the polymerizable compound containing a (meth)acryloyl group contains at least one of a compound represented by the following formula (A) and a compound represented by the following formula (1).

[0007]

[0008] In formula (A), Z ５ , ３ , ４ , ２ , ４ , ６ and Z ２ each independently represent an aromatic ring or an alkylene group, which may be substituted with an alkyl group or an alkoxy group, R １ and R ３ each independently represent an alkylene group having 1 or more and 10 or less carbon atoms, x and y each independently represent an integer of 0 or more, R ２ and R ４ each independently represent a hydrogen atom or a methyl group, Z ３ and Z ４ each independently represent an aromatic ring or an alkyl group, which may be substituted with an alkyl group or an alkoxy group, R ５ and R ６Each of the following independently represents an alkyl group, and t, u, v, and w each represent an integer greater than or equal to 0, satisfying t + v ≤ 4 and u + w ≤ 4. In equation (1), R １ and R ２ Each independently represents a hydrogen atom or a methyl group. n represents an integer of 2 or more, and X represents an alkylene group having 1 to 4 carbon atoms, which may have a group represented by formula (2) bonded to it, and any of the methylene groups may be substituted with a carbonyl group. In formula (2), R ３ represents a hydrogen atom or a methyl group, Z represents an alkylene group with 1 to 4 carbon atoms, p represents an integer of 1 or more, and the wavy line represents the bond position.

[0009] <3> The photocurable composition for photoelectric fusion devices according to <1> or <2>, wherein the content of the photopolymerization initiator is 0.01% by mass or more based on the total amount of the polymerizable compound containing the (meth)acryloyl group. <4> The photocurable composition for photoelectric fusion devices according to any one of <1> to <3>, further comprising a light stabilizer and an antioxidant, wherein the antioxidant comprises a hindered phenol-based antioxidant. <5> The photocurable composition for photoelectric fusion devices according to <4>, wherein the antioxidant comprises an antioxidant with a molecular weight of 1000 or less. <6> The photocurable composition for photoelectric fusion devices according to <3> or <4>, wherein the light stabilizer comprises a hindered amine-based light stabilizer comprising at least one of a secondary amine structure and an N-alkoxy structure. <7> The photocurable composition for photoelectric fusion devices according to any one of <4> to <6>, wherein the content of the antioxidant is 1.5% by mass or less with respect to the total amount of the polymerizable compound containing the (meth)acryloyl group. <8> The photocurable composition for photoelectric fusion devices according to any one of <4> to <7>, wherein the content of the light stabilizer is 1.5% by mass or less with respect to the total amount of the polymerizable compound containing the (meth)acryloyl group. <9> Integrated light intensity of 3000 mJ / cm of light with a wavelength of 365 nm ２A photocurable composition for photoelectric fusion devices according to any one of <1> to <8>, wherein, when cured to a thickness of 100 μm by irradiation, the yellow index value after heat treatment of the cured material at 230°C for 1 hour is less than 1.8 times the yellow index value before heat treatment of the cured material at 230°C for 1 hour. <10> A component for a photoelectric fusion device comprising a cured product of the photocurable composition for a photoelectric fusion device according to any one of <1> to <9>. <11> A component for a photoelectric fusion device according to <10>, which is an optical waveguide. <12> A component for a photoelectric fusion device according to <10> or <11>, which is an optical waveguide for photonic wire bonding. <13> A photoelectric fusion device comprising the component for a photoelectric fusion device according to <10> or <11>.

[0010] According to one aspect of this disclosure, a photocurable composition for photoelectric fusion devices that can produce cured products with excellent resolution is provided, as well as a component for a photoelectric fusion device and a photoelectric fusion device that can be manufactured using this photocurable composition for photoelectric fusion devices.

[0011] In this specification, numerical ranges expressed using "~" mean a range that includes the numbers before and after "~" as the lower and upper limits. In this specification, 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 this specification, "(meth)acryloyl" refers to methacryloyl, acryloyl, or mixtures thereof. Similarly, "(meth)acrylate" refers to methacrylate, acrylate, or mixtures thereof, and "(meth)acrylic" refers to methacrylic, acrylic, or mixtures thereof.

[0012] [Photocurable Composition for Photoelectric Fusion Devices] The photocurable composition for photoelectric fusion devices of the present disclosure (hereinafter also simply referred to as "photocurable composition") contains a polymerizable compound containing a (meth)acryloyl group (hereinafter also referred to as "polymerizable compound A") and a photopolymerization initiator, wherein the content of the photopolymerization initiator is 0.5% by mass or less with respect to the total amount of the polymerizable compound containing a (meth)acryloyl group.

[0013] The photocurable composition disclosed herein contains polymerizable compound A and a photopolymerization initiator, and by having a photopolymerization initiator content of 0.5% by mass or less relative to the total amount of polymerizable compound A, a cured product with excellent resolution can be produced.

[0014] The photocurable compositions of this disclosure will be described in more detail below.

[0015] <Polymerizable compound containing a (meth)acryloyl group ("Polymerizable compound A")> The photocurable composition of the present disclosure contains polymerizable compound A (i.e., a polymerizable compound containing a (meth)acryloyl group). The number of (meth)acryloyl groups in polymerizable compound A is preferably two or more, more preferably two to five. The photocurable composition of the present disclosure may contain only one polymerizable compound A, or it may contain two or more polymerizable compounds. The photocurable composition of the present disclosure may contain both a polymerizable compound containing two or more (meth)acryloyl groups and a polymerizable compound containing one (meth)acryloyl group.

[0016] (Fluorene-containing (meth)acrylate) A preferred embodiment of polymerizable compound A is a fluorene-containing (meth)acrylate containing a fluorene structure. The fluorene-containing (meth)acrylate preferably contains two or more (meth)acryloyl groups. That is, the fluorene-containing (meth)acrylate is preferably a bifunctional or more fluorene-containing (meth)acrylate. When the photocurable composition of this disclosure contains a fluorene-containing (meth)acrylate, the refractive index of the cured product obtained by curing the photocurable composition tends to be high. Cured products with a high refractive index are very useful as components for photoelectric fusion devices (e.g., optical waveguides).

[0017] Specific examples of fluorene-containing (meth)acrylates include compounds represented by the following formula (A). The photocurable compositions of this disclosure may contain only one fluorene-containing (meth)acrylate or two or more.

[0018]

[0019] In the above formula (A), Z１ and Z ２ each independently represents an aromatic ring or an alkylene group which may be substituted with an alkyl group or an alkoxy group. The aromatic ring is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring. Also, the number of carbon atoms of the alkylene group is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less.

[0020] R １ and R ３ each independently represents an alkylene group having 1 to 10 carbon atoms, the number of carbon atoms thereof is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, still more preferably 2 or 3, and particularly preferably 2 (ethylene group). x and y each independently represents an integer of 0 or more, preferably 0 or more and 2 or less, more preferably 0 or 1.

[0021] R ２ and R ４ each independently represents a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0022] Z ３ and Z ４ each independently represents an aromatic ring or an alkyl group which may be substituted with an alkyl group or an alkoxy group. Z ３ and Z ４ each independently is preferably an aromatic ring, more preferably a benzene ring or a naphthalene ring, and still more preferably a naphthalene ring.

[0023] R ５ and R ６ each independently represents an alkyl group. R ５ or R ６ The alkyl group represented by has preferably 1 to 4 carbon atoms. As the above alkyl group, a methyl group or an ethyl group is more preferable, and a methyl group is still more preferable.

[0024] t, u, v, and w each represent integers greater than or equal to 0, satisfying t + v ≤ 4 and u + w ≤ 4. Independently, t and u are preferably between 0 and 2, more preferably 0 or 1. Independently, v and w are preferably between 0 and 2, more preferably 0 or 1, and even more preferably 0.

[0025] Specific examples of compounds represented by formula (A) include 9,9-bis(4-(meth)acryloyloxyphenyl)fluorene, 9,9-bis(4-(2-(meth)acryloyloxyethoxy)phenyl)fluorene, 9,9-bis(4-(3-(meth)acryloyloxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-(meth)acryloyloxypropoxy)phenyl)fluorene, 9,9-bis(4-(meth)acryloyloxy-3-methylphenyl)fluorene, and 9,9-bis[4-(2-(meth)acryloyloxyethoxy)-3- Fluorene, 9,9-Methylphenyl, 9,9-Bis[4-(3-(meth)acryloyloxypropoxy)-3-methylphenyl]fluorene, 9,9-Bis[4-(2-(meth)acryloyloxypropoxy)-3-methylphenyl]fluorene, 9,9-Bis(4-(meth)acryloyloxy-3-ethylphenyl)fluorene, 9,9-Bis[4-(2-(meth)acryloyloxyethoxy)-3-ethylphenyl]fluorene, 9,9-Bis[4-(3-(meth)acryloyloxypropoxy)-3-ethylphenyl]fluorene, 9,9-Bi S[4-(2-(meth)acryloyloxypropoxy)-3-ethylphenyl]fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-1,8-diphenylfluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-1,8-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-1,8-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-diphenylfluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-diphenyl Fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-diphenylfluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-4,5-diphenylfluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-4,5-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-4,5-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-1,8-bis(naphtho-1-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-1,8-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-1,8-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-1-yl)fluorene Oren, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-1-yl)fluorene Len, 9,9-bis(2-(meth)acryloyloxyethyl)-4,5-bis(naphtho-1-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-4,5-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-4,5-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-1,8-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-1,8-bis(naphtho-2-yl)fluorene , 9,9-bis(2-(meth)acryloyloxypropyl)-1,8-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-2-yl)fluorene, 9,This includes 9-bis(3-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-4,5-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-4,5-bis(naphtho-2-yl)fluorene, and 9,9-bis(2-(meth)acryloyloxypropyl)-4,5-bis(naphtho-2-yl)fluorene.

[0026] Examples of preferred compounds among the above include 9,9-bis(4-(meth)acryloyloxyphenyl)fluorene, 9,9-bis(4-(2-(meth)acryloyloxyethoxy)phenyl)fluorene, 9,9-bis(4-(3-(meth)acryloyloxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-(meth)acryloyloxypropoxy)phenyl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-diphenylfluorene, and 9,9-bis(3-(meth)acryloyloxypropyl). -2,7-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-diphenylfluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-diphenylfluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(3-( 9,9-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis (2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene, and 9,It contains 9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene.

[0027] Examples of even more preferred compounds include 9,9-bis(4-(2-(meth)acryloyloxyethoxy)phenyl)fluorene, 9,9-bis(4-(3-(meth)acryloyloxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-(meth)acryloyloxypropoxy)phenyl)fluorene, and 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-1-yl)fluorene. Oren, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-2,7-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-bis 9,9-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-1-yl)fluorene, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-2,7-bis(naphtho-2-yl)fluorene, 9,9-bis(2-(meth)acryloyl This includes 9,9-bis(2-(meth)acryloyloxyethyl)-3,6-bis(naphtho-2-yl)fluorene, 9,9-bis(3-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene, and 9,9-bis(2-(meth)acryloyloxypropyl)-3,6-bis(naphtho-2-yl)fluorene.

[0028] Fluorene-containing (meth)acrylate may be commercially available or synthesized. Examples of commercially available products include the trade name A-BPEF (manufactured by Shin-Nakamura Kagaku Kogyo Co., Ltd.) and the trade names OGSOL EA-0200 or EA-0300 (both manufactured by Osaka Gas Chemical Co., Ltd.).

[0029] On the other hand, commercially available fluorene derivative diols (e.g., bisphenoxyethanol fluorene or bisphenol fluorene) can be synthesized by (meth)acryloyl esterification using (meth)acrylic anhydride or (meth)acryloyl chloride. Furthermore, 9,9-bis(2-(meth)acryloyloxyethyl)-2,7-bis(naphtho-2-yl)fluorene (DNEOA) can also be synthesized by the following synthesis scheme.

[0030]

[0031] When the photocurable composition of this disclosure contains fluorene-containing (meth)acrylate, the content of fluorene-containing (meth)acrylate is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 30% to 60% by mass, based on the total amount of polymerizable compounds contained in the photocurable composition of this disclosure. When the amount of fluorene-containing (meth)acrylate is within the above range, the refractive index of the resulting cured product tends to be high, and the Abbe number also tends to be high. Furthermore, the transparency and heat resistance of the cured product tend to be good.

[0032] (Thio(meth)acrylate) A preferred embodiment of polymerizable compound A is thio(meth)acrylate. The thio(meth)acrylate preferably contains two or more (meth)acryloyl groups. That is, the thio(meth)acrylate is preferably a bifunctional or more thio(meth)acrylate. When the photocurable composition of this disclosure contains thio(meth)acrylate, the refractive index of the cured product obtained by curing the photocurable composition tends to increase. In this case, the Abbe number of the cured product also tends to increase further.

[0033] The above examples of thio(meth)acrylates include thio(meth)acrylates represented by the following formula (1) (hereinafter also simply referred to as "compounds represented by formula (1)"). The photocurable composition may contain only one compound represented by formula (1), or it may contain two or more compounds.

[0034]

[0035] In formula (1), R １ and R ２ Each of these independently represents a hydrogen atom or a methyl group. n represents an integer of 2 or more. n is preferably 3 or more, and more preferably 5 or more. Furthermore, n is preferably 20 or less, more preferably 15 or less, even more preferably 12 or less, and particularly preferably 10 or less.

[0036] X represents an alkylene group having 1 to 4 carbon atoms, which may have a group represented by the following formula (2) bonded to it, and which may have one or more methylene groups substituted with carbonyl groups. The alkylene group preferably has 2 to 4 carbon atoms, and more preferably 2 or 3 carbon atoms. The methylene groups constituting the alkylene group do not have to be substituted with carbonyl groups. On the other hand, if a methylene group is substituted with a carbonyl group, the number of carbonyl groups is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2 carbonyl groups.

[0037]

[0038] In equation (2), R ３ represents a hydrogen atom or a methyl group. Z represents an alkylene group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms, and even more preferably 1 (methylene group). p represents an integer of 1 or more, preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. When p is 2 or more, each Z may be the same or different. The number of groups represented by formula (2) bonded to the alkylene group may be 0, but preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, even more preferably 1 or 2 carbon atoms, and especially preferably 2 carbon atoms. When multiple groups represented by formula (2) are bonded to the alkylene group, the structures of each substituent may be the same or different.

[0039] Specific examples of thio(meth)acrylates represented by formula (1) above include the compounds represented by formula (3) and formula (4) below.

[0040]

[0041] In equations (3) and (4) above, X １１ ~X １４ Each of these independently represents an alkylene group having 1 to 4 carbon atoms, which may be bonded to a group represented by formula (2) above. The number of carbon atoms in the alkylene group is more preferably 1 to 3, even more preferably 1 or 2, and particularly preferably 2. Each of e, f, g, and h is an integer of 2 or more, preferably 2 to 6, more preferably 2 to 5, and even more preferably 2 or 3. １１ ~R １４ Each of these independently represents either a methyl group or a hydrogen atom.

[0042] Specific examples of compounds represented by formula (3) or formula (4) above include compounds represented by the following formulas.

[0043]

[0044] The weight-average molecular weight of the thio(meth)acrylate is preferably 200 or more, and more preferably 1000 or more. Furthermore, the weight-average molecular weight of the thio(meth)acrylate is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 20,000 or less, particularly preferably 10,000 or less, and even more preferably 5,000 or less. When the weight-average molecular weight of the thio(meth)acrylate is within the above range, the refractive index of the cured product of the photocurable composition tends to increase further, and the Abbe number tends to increase further.

[0045] The above thio(meth)acrylate can be synthesized, for example, by the following method: Prepare a polythiol, and when all the thiol groups contained in the polythiol are considered to be 1 equivalent, convert 0.5 equivalents to 0.9 equivalents of thiol groups into a functional group represented by the following formula.

[0046]

[0047] In the above formula, X ２１ R represents a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, preferably a chlorine atom. ２１ represents a hydrogen atom or a methyl group.

[0048] As a specific example, a method can be used in which a polythiol compound is reacted with an alkyl carbonyl halide compound such as 3-chloropropionyl chloride to convert the thiol group in the polythiol compound into the functional group represented by the above structural formula. Then, by performing a β-elimination reaction and an enthiol reaction on the compound obtained above using known methods, a thio(meth)acrylate can be obtained.

[0049] Furthermore, the above-mentioned thio(meth)acrylate can also be obtained by a synthesis method that includes, for example, a step of reacting a polythio(meth)acrylate compound with a polythiol compound by an enthiol reaction using a known method.

[0050] When the photocurable composition of this disclosure contains thio(meth)acrylate, the content of thio(meth)acrylate is preferably 10% to 90% by mass, more preferably 20% to 80% by mass, and even more preferably 30% to 60% by mass, based on the total amount of polymerizable compounds contained in the photocurable composition of this disclosure. When the amount of thio(meth)acrylate is within the above range, the refractive index of the resulting cured product tends to be high, and the Abbe number also tends to be high. Furthermore, the transparency and heat resistance of the cured product tend to be good.

[0051] From the viewpoint of the refractive index and Abbe number of the resulting cured product, polymerizable compound A preferably contains at least one of the above-mentioned bifunctional or more fluorene-containing (meth)acrylate (for example, the compound represented by formula (A) above) and the above-mentioned bifunctional or more thio(meth)acrylate (for example, the compound represented by formula (1) above), and more preferably contains at least one of the above-mentioned compound represented by formula (A) and the compound represented by formula (1) above. When the photocurable composition of the present disclosure contains at least one of the bifunctional or more fluorene-containing (meth)acrylate and the bifunctional or more thio(meth)acrylate, the total content of the bifunctional or more fluorene-containing (meth)acrylate and the bifunctional or more thio(meth)acrylate is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on the total amount of polymerizable compounds contained in the photocurable composition of the present disclosure. When the total content of bifunctional or higher fluorene-containing (meth)acrylates and bifunctional or higher thio(meth)acrylates falls within the above range, the resulting cured product tends to have a higher refractive index and a higher Abbe number. Furthermore, the transparency and heat resistance of the cured product also tend to be good.

[0052] (Other (meth)acrylates) The photocurable compositions of this disclosure may contain, as polymerizable compound A (i.e., polymerizable compound containing a (meth)acryloyl group), compounds other than the fluorene-containing (meth)acrylates and thio(meth)acrylates described above (hereinafter also referred to as other (meth)acrylates). In the following examples, the notation "(Ca-b)" after alkylene, alkyl, alkoxy, etc. indicates that the number of carbon atoms in the alkylene group, alkyl group, alkoxy group, etc. is a or more and b or less.

[0053] Other examples of (meth)acrylates include: di(meth)acrylates of alkylene (C2-10) glycols such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate; polyalkylene (C2-4) glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate; bisphenol A type di(meth)acrylates such as 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane; This includes tricyclodecanedimethanol di(meth)acrylate; alkane polyol poly(meth)acrylates such as trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; tri(meth)acrylates of alkane polyol (C2-4) alkylene oxide adducts such as trimethylolpropane and glycerin; tri(meth)acrylates having a triazine ring such as tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate; 4,4'-bis(methacryloylthio)diphenyl sulfide; trialyl cyanurate; trialyl isocyanurate; trialyl trimellitate; and others. Other examples of (meth)acrylates include oligomers of the compounds exemplified above.

[0054] Other examples of (meth)acrylates include monofunctional (meth)acrylates. Examples of monofunctional (meth)acrylates include: alkyl (C1-24) (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; haloalkyl (C1-10) (meth)acrylates such as trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, and hexafluoroisopropyl (meth)acrylate; and cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate. Bridged cyclic (meth)acrylates such as dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, and tricyclodecanyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; hydroxyalkyl (C2-10) (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; phenoxyalkyl (C1-10) (meth)acrylates such as phenoxyethyl (meth)acrylate; alkoxy (C1-10) (alkyl (C1-10) (meth)acrylates such as methoxyethyl (meth)acrylate; glycidyl (meth)acrylate; dimethylamino (meth)acrylate; (meth)acrylamide; This includes tetrahydrofurfuryl (meth)acrylate; O-phenylphenoxyethyl acrylate; and others.

[0055] From the viewpoint of the refractive index of the resulting cured product, the compound represented by the following formula (B) is preferred as the monofunctional (meth)acrylate.

[0056]

[0057] In formula (B), R ｂ１represents a hydrogen atom or a methyl group, A represents an alkylene group having 1 to 5 carbon atoms, n represents 0 or 1, R ｂ２ This represents an aryl group.

[0058] In formula (B), R ｂ１ This is a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0059] In formula (B), the alkylene group represented by A has 1 to 5 carbon atoms, preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0060] In equation (B), n is either 0 or 1. When n is 0, A and R ｂ２ They are directly joined together.

[0061] In formula (B), R ｂ２ This is an aryl group, preferably a phenyl group, a naphthyl group, or a biphenyl group.

[0062] Specific examples of compounds represented by formula (B) below include, for example, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and compounds (B-1) to (B-3) listed below. Compound (B-1) is O-phenylphenoxyethyl acrylate (OPPEOA).

[0063]

[0064] If the photocurable composition of the present disclosure contains a monofunctional (meth)acrylate (for example, a compound represented by formula (B)), the content of the monofunctional (meth)acrylate (for example, a compound represented by formula (B)) is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on the total amount of polymerizable compounds contained in the photocurable composition of the present disclosure.

[0065] From the viewpoint of the refractive index and Abbe number of the resulting cured product, polymerizable compound A is more preferably comprising: a monofunctional (meth)acrylate (for example, a compound represented by formula (B)); and at least one of a bifunctional or more fluorene-containing (meth)acrylate (for example, a compound represented by the aforementioned formula (A)); and a bifunctional or more thio(meth)acrylate (for example, a compound represented by the aforementioned formula (1)). In this embodiment, the content of the monofunctional (meth)acrylate (for example, a compound represented by formula (B)) is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on the total amount of polymerizable compounds contained in the photocurable composition of this disclosure. In the above embodiment, the total content of the bifunctional or higher fluorene-containing (meth)acrylate and the bifunctional or higher thio(meth)acrylate is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on the total amount of polymerizable compounds contained in the photocurable composition of the present disclosure.

[0066] In the photocurable composition of this disclosure, the content of polymerizable compound A is preferably 60% by mass or more, and more preferably 70% by mass or more, based on the total amount of the photocurable composition. When the total amount of polymerizable compound A is within the above range, a cured product with high strength is easily obtained. The upper limit of the content of polymerizable compound A is, for example, 99% by mass, 98% by mass, etc.

[0067] <Photopolymerization Initiator> The photocurable composition of the present disclosure contains a photopolymerization initiator. The photocurable composition of the present disclosure may contain only one type of photopolymerization initiator, or it may contain two or more types.

[0068] Examples of photopolymerization initiators include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-benzyl-2-(dimethylamino)-4'-morpholinobtyrophenone, 1,2-octanedione 1-[4-(phenylthio)phenyl]-2-(o-benzoyl oxime), ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(o-acetyl oxime), 1-hydroxyticrohexyl-phenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropanone.

[0069] Photopolymerization initiators may be commercially available products. Examples of commercially available products include: Omnirad TPO N (trade name), Omnirad 819 (BAPO, trade name), Omnirad 369 (trade name), Omnirad 184 (trade name), Omnirad 1173 (trade name) (all manufactured by IGM Resins B.V.); Irgacure OXE01 (trade name), Irgacure OXE02 (trade name), Irgacure OXE03 (trade name), Irgacure OXE04 (trade name) (all manufactured by BASF); NCI-831 (trade name), NCI-930 (trade name) (both manufactured by ADEKA); these can be used alone or in combination of two or more types.

[0070] Among the above, Omnirad 369E and Omnirad 184 are preferred.

[0071] The absorption wavelength of the photopolymerization initiator is appropriately selected according to the wavelength of the irradiated light. The photopolymerization initiator preferably absorbs light with a wavelength of 200 nm to 400 nm, and more preferably absorbs light with a wavelength of 230 nm to 380 nm.

[0072] In the photocurable composition of this disclosure, the content of the photopolymerization initiator is 0.5% by mass or less relative to the total amount of polymerizable compound A (i.e., a polymerizable compound containing a (meth)acryloyl group), as described above. This makes it possible to produce a cured product with excellent resolution. From the viewpoint of further improving the resolution of the cured product, the content of the photopolymerization initiator relative to the total amount of polymerizable compound A is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and even more preferably 0.3% by mass or less. The lower limit of the content of the photopolymerization initiator relative to the total amount of polymerizable compound A is, for example, 0.01% by mass, 0.03% by mass, 0.05% by mass, 0.1% by mass, etc.

[0073] <Antioxidants> The photocurable compositions of the present disclosure preferably contain at least one antioxidant. For specific examples of antioxidants, see, for example, International Publication No. 2023 / 188978.

[0074] The antioxidant preferably includes a hindered phenol antioxidant. Examples of hindered phenol antioxidants include: triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, Examples include N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, and 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0075] The antioxidant preferably contains an antioxidant with a molecular weight of 1000 or less (for example, a hindered phenol-based antioxidant with a molecular weight of 1000 or less). This further improves the heat resistance of the cured product.

[0076] If the photocurable composition of the present disclosure contains an antioxidant, the antioxidant content is preferably 3.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less, relative to the total amount of polymerizable compound A, from the viewpoint of the resolution of the cured product. If the photocurable composition of the present disclosure contains an antioxidant, the lower limit of the antioxidant content relative to the total amount of polymerizable compound A is, for example, 0.01% by mass, 0.03% by mass, 0.05% by mass, 0.1% by mass, etc., from the viewpoint of the resolution of the cured product.

[0077] <Light stabilizers> The photocurable compositions of the present disclosure preferably contain at least one light stabilizer. For specific examples of light stabilizers, see, for example, International Publication No. 2023 / 188978.

[0078] Preferably, the light stabilizer is a hindered amine-based light stabilizer (HALS).

[0079] Examples of hindered amine-based light stabilizers include: (1,2,2,6,6-pentamethyl-piperidine-4-yl) methacrylic acid, bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidinyl) decandioate ester, a mixture consisting of 70% by mass of the reaction product of 1,1-dimethylethyl hydroperoxide and octane and 30% by mass of polypropylene, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, Examples include tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, a mixture of 2,2,6,6-tetramethyl-4-piperidyl-1,2,3,4-butanetetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate, a mixture of 1,2,2,6,6-pentamethyl-4-piperidyl-1,2,3,4-butanetetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate, bis(1-undecaneoxy-2,2,6,6-tetramethylpiperidine-4-yl)carbonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and the like.

[0080] The light stabilizer preferably includes a hindered amine-based light stabilizer containing at least one of a secondary amine structure and an N-alkoxy structure. This further improves the heat resistance of the cured product.

[0081] From the viewpoint of further improving the heat resistance of the cured product, the photocurable composition of the present disclosure is particularly preferably comprising a hindered amine-based light stabilizer containing at least one of a secondary amine structure and an N-alkoxy structure, and a hindered phenol-based antioxidant with a molecular weight of 1000 or less.

[0082] The light stabilizer preferably contains a light stabilizer with a molecular weight of 1000 or less (for example, a hindered amine-based light stabilizer (HALS) with a molecular weight of 1000 or less). This further improves the heat resistance of the cured product.

[0083] When the photocurable composition of the present disclosure contains a light stabilizer, the content of the light stabilizer is preferably 3.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less, relative to the total amount of polymerizable compound A, from the viewpoint of the resolution of the cured product. When the photocurable composition of the present disclosure contains a light stabilizer, the lower limit of the content of the light stabilizer relative to the total amount of polymerizable compound A is, for example, 0.01% by mass, 0.03% by mass, 0.05% by mass, 0.1% by mass, etc., from the viewpoint of the resolution of the cured product.

[0084] <Silane Coupling Agents> The photocurable compositions of the present disclosure may contain at least one silane coupling agent. This further improves the balance of performance of the cured product, including high refractive index, low curing shrinkage, and glass adhesion. For specific examples of silane coupling agents, see, for example, International Publication No. 2023 / 188978.

[0085] Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(A Examples include minoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, 3-trimethoxysilylpropyl succinic anhydride, and the like. These silane coupling agents are readily available on the market, for example, because they are sold by Shin-Etsu Chemical Co., Ltd. and others.

[0086] When the photocurable composition of the present disclosure contains a silane coupling agent, the content of the silane coupling agent is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, and even more preferably 1.5% by mass or less, based on the total amount of polymerizable compound A, from the viewpoint of the resolution of the cured product. When the photocurable composition of the present disclosure contains a silane coupling agent, the lower limit of the content of the silane coupling agent relative to the total amount of polymerizable compound A is, for example, 0.01% by mass, 0.03% by mass, 0.05% by mass, 0.1% by mass, etc., from the viewpoint of the resolution of the cured product.

[0087] <Other Components> The photocurable compositions of this disclosure may contain other components besides those described above. Examples of other components include ultraviolet absorbers. For other components, see, for example, International Publication No. 2023 / 188978.

[0088] <Preferred viscosity of photocurable composition> From the viewpoint of handling, the photocurable composition of the present disclosure preferably has a viscosity at 25°C measured with an E-type viscometer of 100 mPa·s or more and 20,000 mPa·s or less, and more preferably 200 mPa·s or more and 10,000 mPa·s or less.

[0089] <Heat Resistance of Cured Products of Photocurable Compositions> It is preferable that the cured products of the photocurable compositions of this disclosure and the components for photoelectric fusion devices (e.g., optical waveguides) containing these cured products have excellent heat resistance. An indicator of the heat resistance of the cured product is, for example, the change in the yellow index value (YI value) due to heating. For example, the photocurable composition of this disclosure has an integrated light intensity of 3000 mJ / cm² of light with a wavelength of 365 nm. ２ When a cured product with a thickness of 100 μm is obtained by irradiation, the yellow index value (YI value) after heat treatment of the cured product at 230°C for 1 hour is preferably less than 3.0 times, and more preferably less than 1.8 times, the yellow index value (YI value) before heat treatment of the cured product at 230°C for 1 hour.

[0090] The means for improving the heat resistance of the cured product are as described in the explanation of each component above. For example, components that can improve the heat resistance of the cured product include antioxidants with a molecular weight of 1000 or less (preferably hindered phenol-based antioxidants) and hindered amine-based light stabilizers containing an N-alkoxy structure (preferably hindered amine-based light stabilizers containing an N-alkoxy structure with a molecular weight of 1000 or less).

[0091] <Refractive Index of Cured Products of Photocurable Compositions> The cured products of the photocurable compositions of this disclosure and the components for photoelectric fusion devices (e.g., optical waveguides) containing these cured products preferably have excellent refractive index. For example, the photocurable composition of this disclosure has an integrated light intensity of 3000 mJ / cm² for light with a wavelength of 365 nm. ２When a cured product with a thickness of 100 μm is obtained by irradiation, the refractive index of light with a wavelength of 589 nm is preferably 1.60 or higher, more preferably 1.61 or higher.

[0092] The means for improving the refractive index of the cured product are as described in the explanation of each component above. Components that can improve the refractive index of the cured product include, for example, the fluorene-containing (meth)acrylate and thio(meth)acrylate mentioned above.

[0093] <Infrared Transmittance of Cured Products of Photocurable Compositions> It is preferable that the cured products of the photocurable compositions of this disclosure and the components for photoelectric fusion devices (e.g., optical waveguides) containing these cured products have excellent infrared transmittance. For example, the photocurable composition of this disclosure has an integrated light intensity of 3000 mJ / cm² for light with a wavelength of 365 nm. ２ When a cured product with a thickness of 100 μm is obtained by irradiation, the transmittance of infrared light with a wavelength of 1310 nm is preferably 95% or more.

[0094] The infrared transmittance of the cured product can be adjusted, for example, by adjusting the composition of the photocurable composition of the present disclosure.

[0095] [Cured product] A cured product of the photocurable composition of the present disclosure is obtained by irradiating the photocurable composition of the present disclosure with light. The wavelength of the light is preferably 200 nm to 700 nm, and more preferably 500 nm to 600 nm. Specific methods of light irradiation include, for example: arranging the photocurable composition in a mold such as a glass mold (for example, the photocurable composition between glass members as a glass mold) and irradiating the arranging photocurable composition with light; irradiating a photocurable composition filled in a container with laser light to obtain a three-dimensional object (e.g., an optical waveguide) as a cured product; and so on.

[0096] [Components for photoelectric fusion devices, photoelectric fusion devices] The component for photoelectric fusion devices of the present disclosure includes a cured product of the photocurable composition of the present disclosure. Therefore, the component for photoelectric fusion devices of the present disclosure has excellent resolution. Preferably, the component for photoelectric fusion devices of the present disclosure is an optical waveguide. The photoelectric fusion device of the present disclosure comprises the component for photoelectric fusion devices.

[0097] For information on components for photoelectric fusion devices (e.g., optical waveguides) and photoelectric fusion devices, see, for example, Optica, Vol. 5, Issue 7, pp.876-883 (2018).

[0098] Particularly preferred as a component for photoelectric integrated devices in this disclosure is an optical waveguide for photonic wire bonding. Here, photonic wire bonding refers to a technique for connecting optical elements mounted on a chip using optical waveguides during the fabrication process of a silicon photonics-based photonic integrated circuit (PIC), in which various optical elements are integrated onto a single chip. This optical waveguide for photonic wire bonding can be formed using laser direct writing nano 3D printing technology. For more information on photonic wire bonding, see, for example, Japanese Patent Publication No. 2025-501851.

[0099] The following are examples of the present disclosure, but the present disclosure is not limited to these examples.

[0100] <Preparation of materials> The following compounds were used in the following examples and comparative examples.

[0101] (Polymerizable compounds) ・OPPEOA (O-phenylphenoxyethyl acrylate) ・A-BPEF (Fluorene skeleton-containing bifunctional acrylate represented by the following structural formula, OGSOL EA-0200, manufactured by Osaka Gas Chemical Co., Ltd.)

[0102]

[0103] A composition containing the following sulfur-containing compound (1a) (sulfur-containing tetrafunctional acrylate) prepared by the synthesis example described below.

[0104]

[0105] (Photopolymerization initiator) ・Omnirad 369E (manufactured by IGM Resins B.V., α-aminoalkylphenone type photopolymerization initiator, 2-benzyl-2-(dimethylamino)-4'-morpholinobtyrophenone)

[0106] (Silane coupling agent) ・KBE-503 (manufactured by Shin-Etsu Chemical Co., Ltd., 3-methacryloxypropyltriethoxysilane)

[0107] (Antioxidants) ・Irganox 1135 (manufactured by BASF Japan, hindered phenol antioxidant, molecular weight as shown in Table 1) ・AO-80 (manufactured by Adeka Corporation, "Adeka Stab AO-80", hindered phenol antioxidant, molecular weight as shown in Table 1) ・AO-60 (manufactured by Adeka Corporation, "Adeka Stab AO-60", hindered phenol antioxidant, molecular weight as shown in Table 1)

[0108] (Light stabilizers) ・LA-81 (Adeka Corporation's "Adeka Stab LA-81", hindered amine light stabilizer (HALS), N-alkoxy structure (>NO-alkyl structure), molecular weight as shown in Table 1) ・LA-82 (Adeka Corporation's "Adeka Stab LA-82", hindered amine light stabilizer (HALS), tertiary amine structure, molecular weight as shown in Table 1) ・622 (BASF Japan's "Tinuvin 622 SF", hindered amine light stabilizer (HALS), tertiary amine structure, molecular weight as shown in Table 1)

[0109] <Example of synthesis of a composition containing sulfur-containing compound (1a)> 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (hereinafter referred to as "trithiol X") (100.0 g, 383.9 mmol) was placed in a four-necked flask equipped with a stirrer, thermometer, nitrogen introduction line, and dropping funnel, and diluted with dichloromethane (100 mL) before stirring was started. Next, 3-chloropropionyl chloride (121.84 g, 959.7 mmol) was added dropwise while cooling the reaction mixture in an ice bath so that the internal temperature was 40°C or lower. After stirring the reaction mixture at room temperature for 48 hours, pure water (100 mL) was added, and the organic phase was separated by liquid-liquid extraction. The obtained organic phase was washed twice with saturated sodium bicarbonate aqueous solution (100 mL) to obtain a dichloromethane solution of a composition in which some of the thiol groups of trithiol X were esterified with 3-chloropropionic acid (a group of compounds including the trisubstituted, disubstituted, and monosubstituted compounds described below). For this composition, the peak area ratio of the trisubstituted:disubstituted:monosubstituted compounds, as identified by high-performance liquid chromatography (HPLC), was 56:38:6.

[0110]

[0111]

[0112]

[0113] To the dichloromethane solution of the above composition, 4-methoxyphenol (150 mg) was further added as a polymerization inhibitor and dissolved while stirring at room temperature. Then, while cooling the reaction solution in an ice bath so that the internal temperature was 40°C or lower, triethylamine (116.5 g, 1152 mmol) was added dropwise. After stirring the reaction solution at room temperature for 1 hour, 1 M hydrochloric acid (300 mL) was added and the organic phase was separated by liquid-liquid extraction. The obtained organic phase was passed through silica gel (100 mL), 4-methoxyphenol (150 mg) was added as a polymerization inhibitor, and concentration was performed under reduced pressure to obtain a colorless and transparent composition (132.5 g) containing the above sulfur-containing compound (1a). When the molecular weight was measured by the following method (GPC), the number average molecular weight (Mn) was 500 and the weight average molecular weight (Mw) was 1600.

[0114] (Molecular Weight Measurement) The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the composition containing the sulfur-containing compound (1a) obtained in the above synthesis example were measured by gel permeation chromatography (GPC) using the following procedure: (1) The above composition was dissolved in tetrahydrofuran so that the concentration of the sample solution was 1 g / 100 mL. Then, this solution was filtered using a pore size 1 μm filter (Membrane Solutions, product name: Syringe Filter PTFE013100) to remove insoluble components and obtain the sample solution. (2) Molecular weight measurement A GPC analyzer (product name: Alliance, manufactured by WATERS Inc.) was used, and tetrahydrofuran (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatography) was flowed as the eluent at a flow rate of 1.0 mL per minute. Three analytical columns (gel permeation columns, manufactured by Agilent Inc., product name: PLgel 5 μm Mixed-C) were stabilized in a 40°C constant temperature bath. 10 μL of the sample solution was injected into the column and the measurement was performed. A differential refractive index (RI) detector was used as the detector. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. Several types of monodisperse polystyrene (manufactured by Agilent Inc.) with known molecular weights were used as standard samples in the calibration curve.

[0115] [Examples 1-14, Comparative Example 1] <Preparation of Photocurable Composition> The components shown in Tables 1 and 2 were mixed to obtain a photocurable composition (i.e., a photocurable composition for photoelectric fusion devices). The numerical values ​​in the columns for each component in Tables 1 and 2 represent the amount (parts by mass) of the corresponding component. Blank spaces in Tables 1 and 2 indicate that the corresponding component is not present.

[0116] <Evaluation> The obtained photocurable composition and the cured product of this photocurable composition were evaluated as follows.

[0117] (Infrared transmittance) A 100 μm thick spacer was placed on the outer periphery of a glass plate (EAGLE-XG, manufactured by Corning), and a photocurable composition was dropped into the central area surrounded by the spacer. Next, another glass plate (EAGLE-XG, manufactured by Corning) was placed on top of the spacer and photocurable composition on the glass plate. In this way, the spacer and photocurable composition were placed between the two glass plates, and these two glass plates were fixed in place with a clip. Next, light with a wavelength of 365 nm was shone on the photocurable composition sandwiched between the two glass plates at a rate of 3000 mJ / cm² through one of the glass plates. ２ The photocurable composition was cured by irradiating it with the cumulative light intensity. As a result, a test piece having a laminated structure of "glass plate / cured product of photocurable composition (thickness 100 μm) / glass plate" was obtained.

[0118] The transmittance of the obtained test specimens at a wavelength of 1310 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer (V-770, manufactured by JASCO Corporation). Only two glass plates were used as references. Based on the obtained results, the infrared transmittance of the cured material was evaluated according to the following evaluation criteria. The results are shown in Tables 1 and 2.

[0119] - Criteria for evaluating infrared transmittance - A: Transmittance was 95% or higher. B: Transmittance was less than 95%.

[0120] (Resolution) A photocurable composition was irradiated with a Yb:KGW femtosecond laser to produce a three-dimensional object as a cured product of the photocurable composition. In this process, a single-shot exposure was performed under the conditions of a maximum average power of 10 W, a pulse width of 290 femtoseconds, a maximum pulse energy of 0.2 mJ, a repetition frequency of 1 MHz, and a center wavelength of 515 nm. The resolution was evaluated from the state of the three-dimensional object formed when the irradiation power was varied from 0.25% to 2%. The evaluation criteria were as follows. The results are shown in Tables 1 and 2.

[0121] -Resolution Evaluation Criteria- A: Three-dimensional objects could be manufactured with a resolution of less than 20 μm. B: Three-dimensional objects could be manufactured with a resolution of 20 μm or more.

[0122] (Heat Resistance) Test specimens similar to those used for evaluating infrared transmittance were prepared. The obtained test specimens were heat-treated in an oven at 230°C for 1 hour. The yellow index value (YI value) of the test specimens was measured before and after this heat treatment. From the obtained results, the change in YI value (times) was calculated using the following formula: "Change in YI value (times) = (YI value after heating at 230°C for 1 hour) / (YI value before heating at 230°C for 1 hour)" Based on the change in coloration, the heat resistance of the cured product was evaluated according to the following evaluation criteria. The results are shown in Tables 1 and 2.

[0123] - Heat Resistance Evaluation Criteria - A: Change in YI value is less than 1.8 times B: Change in YI value is 1.8 times or more but less than 3.0 times C: Change in YI value is 3.0 times or more

[0124] (Refractive Index) A PET film (MelinexS) was placed on top of a glass plate (EAGLE-XG, manufactured by Corning), and a 100 μm thick spacer was placed on the outer periphery. The photocurable composition was dripped into the central area surrounded by the spacer. Next, another PET film (MelinexS) was placed on top of the PET film on which the photocurable composition was dripped, and a glass plate (EAGLE-XG, manufactured by Corning) was placed on top of that. As a result, a laminate having a layered structure of "glass plate / PET film / photocurable composition and spacer / PET film / glass plate" was obtained. The obtained laminate was fixed with clips. Next, light with a wavelength of 365 nm was shone on the photocurable composition in the laminate through the glass plate and PET film at a rate of 3000 mJ / cm². ２The photocurable composition was cured by irradiating it with the integrated light intensity. Next, two glass plates, two PET films, and a spacer were removed from the laminate, and the cured film (100 μm thick), which was the cured product of the photocurable composition, was taken out. The refractive index of the obtained cured film was measured using an Abbe refractometer (DR-M2, manufactured by Atago). When measuring the refractive index, RE-3520 (589 nm, D line, manufactured by Atago) was used as an interference filter, and RE-1196 (monobromonaphthalene, manufactured by Atago) was used as an intermediate solution. The sample temperature was set to 25°C, and the measurement was performed. Based on the obtained results, the refractive index of the cured product was evaluated according to the evaluation criteria below. Tables 1 and 2 show the evaluation results and the numerical values ​​of the refractive index.

[0125] - Criteria for evaluating refractive index - A: The refractive index was 1.60 or higher. B: The refractive index was less than 1.60.

[0126]

[0127]

[0128] As shown in Tables 1 and 2, the photocurable compositions of each example, which contained a polymerizable compound containing a (meth)acryloyl group and a photopolymerization initiator, and in which the content of the photopolymerization initiator was 0.5% by mass or less relative to the total amount of the polymerizable compound containing a (meth)acryloyl group, exhibited superior resolution compared to the photocurable composition of Comparative Example 1, in which the content of the photopolymerization initiator was greater than 0.5% by mass.

[0129] Among the examples, the photocurable compositions of Examples 1 to 4, in which the molecular weight of the antioxidant is 1000 or less and the light stabilizer contains an N-alkoxy structure, were able to obtain cured products with excellent heat resistance.

[0130] The disclosure of Japanese Patent Application No. 2024-229318, filed on 25 December 2024, is incorporated herein by reference in its 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 for photoelectric fusion devices, comprising a polymerizable compound containing a (meth)acryloyl group and a photopolymerization initiator, wherein the content of the photopolymerization initiator is 0.5% by mass or less relative to the total amount of the polymerizable compound containing the (meth)acryloyl group.

2. The photocurable composition for an optoelectronic fusion device according to claim 1, wherein the polymerizable compound containing the (meth)acryloyl group contains at least one of a compound represented by the following formula (A) and a compound represented by the following formula (1). [In formula (A), Z １ and Z ２ each independently represents an aromatic ring or an alkylene group which may be substituted with an alkyl group or an alkoxy group, R １ and R ３ each independently represents an alkylene group having 1 to 10 carbon atoms, x and y each independently represent an integer of 0 or more, R ２ and R ４ each independently represents a hydrogen atom or a methyl group, Z ３ and Z ４ each independently represents an aromatic ring or an alkyl group which may be substituted with an alkyl group or an alkoxy group, R ５ and R ６ each independently represents an alkyl group, t, u, v, and w each represent an integer of 0 or more, and are values satisfying t + v ≤ 4 and u + w ≤ 4. In formula (1), R １ and R ２ each independently represents a hydrogen atom or a methyl group. n represents an integer of 2 or more, X represents an alkylene group having 1 to 4 carbon atoms, to which a group represented by formula (2) may be bonded and in which any methylene group may be substituted with a carbonyl group. In formula (2), R ３ represents a hydrogen atom or a methyl group, Z represents an alkylene group having 1 to 4 carbon atoms, p represents an integer of 1 or more, The wavy line represents the bonding position. ] 3. The photocurable composition for photoelectric fusion devices according to claim 1, wherein the content of the photopolymerization initiator is 0.01% by mass or more based on the total amount of the polymerizable compound containing the (meth)acryloyl group.

4. The photocurable composition for photoelectric fusion devices according to claim 1, further comprising a light stabilizer and an antioxidant, wherein the antioxidant comprises a hindered phenol-based antioxidant.

5. The photocurable composition for photoelectric fusion devices according to claim 4, wherein the antioxidant comprises an antioxidant with a molecular weight of 1000 or less.

6. The photocurable composition for photoelectric fusion devices according to claim 4, wherein the light stabilizer comprises a hindered amine-based light stabilizer comprising at least one of a secondary amine structure and an N-alkoxy structure.

7. The photocurable composition for photoelectric fusion devices according to claim 4, wherein the content of the antioxidant is 1.5% by mass or less based on the total amount of the polymerizable compound containing the (meth)acryloyl group.

8. The photocurable composition for photoelectric fusion devices according to claim 4, wherein the content of the light stabilizer is 1.5% by mass or less based on the total amount of the polymerizable compound containing the (meth)acryloyl group.

9. Integrated luminous intensity of light with a wavelength of 365 nm: 3000 mJ / cm² ２ A photocurable composition for photoelectric fusion devices according to claim 1, wherein, when a cured product with a thickness of 100 μm is obtained by irradiation, the yellow index value after heat treatment of the cured product at 230°C for 1 hour is less than 1.8 times the yellow index value of the cured product before heat treatment of the cured product at 230°C for 1 hour.

10. A component for a photoelectric fusion device, comprising a cured product of a photocurable composition for a photoelectric fusion device according to any one of claims 1 to 9.

11. The optical waveguide component for a photoelectric fusion device according to claim 10.

12. The optical waveguide for photonic wire bonding, a component for a photoelectric fusion device according to claim 10.

13. A photoelectric fusion device comprising the photoelectric fusion device component described in claim 10.

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