Curable resin composition, curable resin, and cured product

Abstract

The objective is to provide a curable resin composition that yields a cured product with low absorption (low light absorption loss) in the near-infrared region used in optical communications, excellent heat resistance, and excellent productivity (UV curability). The curable resin composition according to the present invention is characterized by comprising as essential components (A) a polysiloxane resin having one or more reactive groups selected from the group consisting of (meth)acryloyl groups and styryl groups, (B) one or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing a structure represented by general formula (1), and (C) a radical polymerization initiator. [Formula 1] TIFF0007832607000016.tif23101 (In the above general formula (1), R1 and R2 each independently represent a hydrogen atom, a methyl group, a phenyl group, a naphthyl group, a trifluoromethyl group, or a cyclohexyl group or a fluorenyl group to which R1 and R2 are bonded.)

Description

Technical Field

[0001] The present invention relates to a curable resin composition useful as an optical waveguide, or an optical adhesive, or a transparent encapsulant, or related components thereof that can be used in optical applications, such as optical communication applications and optical integrated circuit applications, a cured product obtained by curing the resin composition, and an optical waveguide.

Background Art

[0002] In recent years, the demands for higher speed and higher capacity in communication and signal transmission have been increasing. The importance of signal transmission by light instead of electricity has also been increasing in internal wiring of devices. Such short-distance optical communication technology is called optical interconnect, and as its members, the development of optoelectronic hybrid substrates in which part of the electrical wiring by copper on a printed wiring board is replaced with optical wiring by an optical fiber or an optical waveguide has been actively carried out.

[0003] The required characteristics of materials used for optical waveguides include low absorption in the near-infrared region used in optical communication and excellent productivity. Conventionally, quartz-based materials have been commonly used as materials for optical waveguides, but in recent years, the study of optical waveguides using polymer materials that can be easily processed at low cost has been actively carried out.

[0004] For example, fluorinated polyimide that can be used as an optical material for optical waveguides has been reported (Patent Document 1). However, although fluorinated polyimide-based materials have few CH groups in the molecule and low absorption in the near-infrared region, they require baking at high temperature, so there are problems such as cracks due to stress caused by the difference in linear expansion rate between the substrate and the film, and problems of poor productivity due to an increase in the number of processes because reactive ion etching is required for patterning.

[0005] As a material that enables patterning by photolithography and has no by-products, an organic / inorganic hybrid material having an organic reactive group and a siloxane skeleton has been reported (Patent Document 2). However, it cannot be said that the absorption in the near-infrared region is sufficiently small, and further improvement is required.

[0006] Furthermore, polymer materials for optical waveguides are exposed to high-temperature solder flow during electrical circuit formation, requiring materials with excellent heat resistance. In particular, recently, due to environmental concerns, lead-free solder with a high melting point is being used, leading to an increased demand for polymer materials for optical waveguides with even higher heat resistance.

[0007] Light-emitting and receiving elements that transmit and receive light via optical waveguides on an optoelectronic composite substrate are often sealed with transparent optical adhesives to enhance the reliability of the elements. For example, light-emitting and receiving elements such as a VCSEL (vertically opposed surface-emitting laser element) are connected to the optical waveguide on the substrate using an optical adhesive, and then soldered by reflow soldering to connect the electrical wiring to the light-emitting and receiving elements and to fix the elements in place. Therefore, such optical adhesives are required to have the same performance as the materials used for the optical waveguides.

[0008] To solve these problems, for example, resin compositions characterized by containing a liquid aliphatic epoxy compound and a specific aromatic epoxy compound (Patent Document 3), and curable resin compositions characterized by containing a (meth)acrylic acid ester having an alicyclic hydrocarbon group (Patent Document 4) have been developed. However, the absorption in the near-infrared region is not sufficiently small, and further improvements are needed. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 5-01148 [Patent Document 2] U.S. Patent No. 6,984,483 [Patent Document 3] Japanese Patent Publication No. 2020-184091 [Patent Document 4] Japanese Patent Application Publication No. 11-61081 [Overview of the project] [Problems that the invention aims to solve]

[0010] The object of the present invention is to provide a curable resin composition that yields a cured product with low absorption (low light absorption loss) and excellent heat resistance in the near-infrared region used in optical communications, as well as excellent productivity (UV curability). Furthermore, the object is to provide a cured product obtained by curing the curable resin composition and an optical waveguide equipped with the cured product. [Means for solving the problem]

[0011] The inventors of the present invention conducted diligent research to solve the above problems. As a result, they discovered that a curable resin composition containing a specific (meth)acrylic acid derivative exhibits low light absorption loss, high heat resistance, and excellent UV curability, thus completing the present invention.

[0012] In other words, the present invention is as follows:

[0013] (1) A curable resin composition containing the following components (A) to (C) as essential components. (A) A polysiloxane resin having one or more reactive groups selected from the group consisting of (meth)acryloyl groups and styryl groups. (B) One or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing the structure represented by the following general formula (1) [ka] (In the above general formula (1), R1 and R2 each independently represent a hydrogen atom, a methyl group, a phenyl group, a naphthyl group, a trifluoromethyl group, or a cyclohexyl group or fluorenyl group to which R1 and R2 are bonded, and the hydrogen atom bonded to the aromatic ring may optionally be substituted with a fluorine atom.) (C) Radical polymerization initiator

[0014] The curable resin composition according to (1) above, wherein the (meth)acrylic acid derivative is a compound containing a structure represented by the following general formula (1), and the compound containing a structure represented by the following general formulas (1-1) to (1-5). [Chemical formula]

[0015] (3) The curable resin composition according to (1) or (2) above, wherein the mass ratio of the component (A) to the component (B) is 99:1 to 10:90.

[0016] (4) The curable resin composition according to (1) or (2) above, wherein the component (A) contains structural formulas represented by the following general formulas (2) and (3). [Chemical formula] (In the above general formulas (2) and (3), R3 represents an organic group having 1 to 12 carbon atoms, and R4 and R5 each independently represent a methyl group or a phenyl group.)

[0017] (5) The curable resin composition according to (4) above, wherein the molar ratio of the general formula (2) to the general formula (3) in the component (A) is 1:0.9 to 1:1.5.

[0018] (6) A cured product obtained by curing the curable resin composition according to (1) or (2) above.

[0019] (7) An optical waveguide comprising the cured product according to (6) above. [Advantages of the Invention]

[0020] According to the present invention, by using a polysiloxane resin having a specific reactive group, a (meth)acrylic acid derivative having a specific structure, and a radical polymerization initiator as essential components, a curable resin composition with low light absorption loss, high heat resistance, excellent UV curability, and further excellent handling properties can be provided. [Modes for Carrying Out the Invention]

[0021] Hereinafter, embodiments of the present invention will be described in detail.

[0022] [Curable resin composition] The curable resin composition of this embodiment is characterized by containing (A) a polysiloxane resin, (B) a (meth)acrylic acid derivative, and (C) a radical polymerization initiator as essential components.

[0023] <(A) Polysiloxane resin> The polysiloxane resin has one or more reactive groups selected from the group consisting of (meth)acryloyl groups and styryl groups. Among radical polymerizable groups, it is particularly preferable to have the above reactive groups from the viewpoint of UV curability. In this specification, (meth)acryloyl group means acryloyl group or methacryloyl group.

[0024] The polysiloxane resin may have at least one of the reactive groups, but may also have two or more, or even three or more. For example, (meth)acryloyl groups are particularly preferable due to their excellent UV curability, and styryl groups are particularly preferable due to their excellent low light absorption loss. The ratio can be appropriately selected according to the desired physical properties, and the polysiloxane resin may contain only one of the reactive groups or any of them; it is not particularly limited. From the viewpoint of UV curability, it is more preferable for the polysiloxane resin to have one or more of the reactive groups in a single molecular chain, and particularly preferable for it to have two or more.

[0025] In the polysiloxane resin, a concentration of reactive groups of 500 to 10,000 mmol / kg is preferable because it allows for sufficient curability.

[0026] The polysiloxane resin in this embodiment is not particularly limited as long as it has a siloxane skeleton, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, iso-butyltrimethoxysilane, iso-butyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxy Organotrialalkoxysilanes such as sisilane, p-styrylmethoxysilane, p-styrylethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, or 3-(meth)acryloyloxypropyltriethoxysilane; diorganodialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, methylcyclohexyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, or 3-(meth)acryloyloxypropylmethyldiethoxysilane;Various chlorosilanes such as methyltrichlorosilane, ethyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, 3-(meth)acryloyloxypropyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane or diphenyldichlorosilane, as well as tetraethoxysilane, tetramethoxysilane, diphenylsilanediol, di-p-tolylsilanediol, bis(4-ethylphenyl)silanediol, bis(4-isopropylphenyl)silanediol, dinaphthylsilanediol, bis([1,1' Examples include polysiloxane resins obtained as complete or partial condensates thereof, such as [-biphenyl]-4-yl)silanediol, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, (4-isopropenylphenyl)trimethoxysilane, trimethoxy(4'-vinyl-1-naphthyl)silane, and trimethoxy(4'-vinyl-[1,1'-biphenyl]-4-yl)silane. From the viewpoint of curability and flexibility, polysiloxane resins containing the structural formulas represented by general formulas (2) and (3) below are particularly preferred. [ka]

[0027] In the above general formulas (2) and (3), R3 represents an organic group having 1 to 12 carbon atoms, and R4 and R5 independently represent a methyl group or a phenyl group. The dashed lines indicate the bonding sites.

[0028] Examples of C1-C12 organic groups in R3 include: chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, and t-butyl groups; alkoxy groups such as methoxy and ethoxy groups; cyclic alkyl groups such as cyclohexyl and norbornanyl groups; alkenyl groups such as vinyl, 1-propenyl, allyl, butenyl, and 1,3-butadienyl groups; alkynyl groups such as ethynyl, propynyl, and butynyl groups; halogenated alkyl groups such as trifluoromethyl; alkyl groups having saturated heterocyclic groups such as 3-pyrrolidinopropyl groups; aryl groups such as phenyl groups which may have alkyl substituents; and aralkyl groups such as phenylmethyl and phenylethyl groups. The organic groups may have oxygen atoms or amide bonds between the carbon atoms, and may also have substituents such as hydroxyl groups, halogen atoms, vinyl groups, epoxy groups, glycidoxypropyl groups, styryl groups, and (meth)acryloyloxypropyl groups.

[0029] In the polysiloxane resin, the molar ratio of the structural formulas represented by general formulas (2) and (3) is preferably in the range of 1:0.9 to 1:1.5, and particularly preferably in the range of 1:1 to 1:1.4. When the molar ratio of the structural formula represented by general formula (3) is 0.9 or higher, the amount of hydroxyl groups in the polysiloxane resin can be suppressed, reducing water absorption and decreasing absorption in the near-infrared region. Furthermore, when the molar ratio of the structural formula represented by general formula (3) is 1.5 or lower, the amount of unreacted hydroxyl groups in the polysiloxane resin is reduced, and furthermore, solidification of the polysiloxane resin is suppressed, which is preferable as it improves handling when preparing the curable resin composition.

[0030] The weight-average molecular weight of the polysiloxane resin is preferably 1,000 to 100,000, and more preferably 1,500 to 50,000. A molecular weight of 1,000 or more results in a high molecular weight, making the cured product tough, while a molecular weight of 100,000 or less is preferable because, when used in a curable resin composition, it exhibits good compatibility with (meth)acrylic acid derivatives described later and has excellent handling properties. The weight-average molecular weight is a polystyrene-converted measurement obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as the elution solvent.

[0031] [(A) Method for producing polysiloxane resin] The method for producing the polysiloxane resin in this embodiment is not particularly limited, and known and conventional condensation reactions can be used. The following describes, but is not limited to, a method for producing a polysiloxane resin containing the structural formula represented by the above general formula (2) and the structural formula represented by the above general formula (3).

[0032] The condensation reaction between a compound containing the structural formula represented by the above general formula (2) and a compound containing the structural formula represented by the above general formula (3) is carried out in the presence of an acid or basic catalyst.

[0033] Examples of the acidic catalyst include boric acid, trimethoxyborone, triethoxyborone, tri-n-propoxyborone, triisopropoxyborone, tri-n-butoxyborone, triisobutoxyborone, tri-sec-butoxyborone, tri-tert-butoxyborone, trimethoxyaluminum, triethoxyaluminum, tri-n-propoxyaluminum, triisopropoxyaluminum, tri-n-butoxyaluminum, triisobutoxyaluminum, tri-sec-butoxyaluminum, tri-tert-butoxyaluminum, tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, Examples include tetraisopropoxytitanium (titanium tetraisopropoxide), tetra-n-butoxytitanium, tetraisobutoxytitanium, tetra-sec-butoxytitanium, tetra-tert-butoxytitanium, tetramethoxyzirconium, tetraethoxyzirconium, tetra-n-propoxyzirconium, tetraisopropoxyzirconium, tetra-n-butoxyzirconium, tetraisobutoxyzirconium, tetra-sec-butoxyzirconium, tetra-tert-butoxyzirconium, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, maleic acid, methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc.

[0034] Examples of the basic catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, triethylamine, N-ethyldiisopropylamine, dimethylaminoethanol, triethanolamine, and 2-amino-2-methyl-1-propanol.

[0035] In these catalysts, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, ammonium hydroxide, and triethylamine are particularly preferred.

[0036] The amount of catalyst used is preferably 0.001 to 10% by mass, and particularly preferably 0.01 to 1% by mass, relative to the total mass of the compound containing the structural formula represented by general formula (2) and the compound containing the structural formula represented by general formula (3). A concentration within this range is preferable because it allows the condensation reaction to proceed sufficiently.

[0037] The condensation reaction may be carried out in the absence of a solvent or in the presence of a solvent, but it is preferable to carry it out in the presence of a solvent to ensure homogeneity of the reaction system. The reaction solvent can be any solvent that does not react with the starting materials, and examples include ketones such as acetone and methyl ethyl ketone (MEK); aromatic hydrocarbons such as benzene, toluene, and xylene; glycols such as ethylene glycol, propylene glycol, and hexylene glycol; glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethyl cellosolve, and diethyl carbitol; and amides such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylformamide (DMF). These solvents may be used individually or in combination of two or more. Among these, toluene is preferred.

[0038] Since the condensation reaction is a de-alcoholization condensation reaction, it is preferable to carry out the reaction in the absence of water, and more preferably under an inert gas atmosphere such as nitrogen gas.

[0039] The reaction temperature can be adjusted as needed to achieve the desired molecular weight distribution, and is usually between 30 and 100°C. Similarly, the reaction time can be adjusted as needed, but is usually between 1 and 40 hours.

[0040] After the condensation reaction is complete, the resulting polysiloxane resin is filtered through a membrane filter to remove the reaction solvent and by-product alcohol under reduced pressure. Further purification is preferable if necessary.

[0041] <(B)(meth)acrylic acid derivatives> The (meth)acrylic acid derivative is characterized by being one or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing the structure represented by the following general formula (1). [ka] (In the above general formula (1), R1 and R2 each independently represent a hydrogen atom, a methyl group, a phenyl group, a naphthyl group, a trifluoromethyl group, or a cyclohexyl group or fluorenyl group to which R1 and R2 are bonded, and the hydrogen atom bonded to the aromatic ring may optionally be substituted with a fluorine atom.)

[0042] More specifically, the (meth)acrylic acid derivative is preferably a compound containing a structure represented by the following general formulas (1-1) to (1-5). [ka]

[0043] Furthermore, the curable resin composition according to the present invention must include a derivative represented by the above general formula (1) as (B)(meth)acrylic acid derivative, and preferably includes at least one derivative represented by the above general formulas (1-1) to (1-5), but may include two or more. In addition, the curable resin composition may include (meth)acrylic acid derivatives other than those represented by the above general formulas (1-1) to (1-5) in addition to the derivatives represented by the above general formulas (1-1) to (1-5).

[0044] In this embodiment, by including the (meth)acrylic acid derivative as an essential component, it plays a role in diluting the highly viscous polysiloxane resin when preparing the curable resin composition, thereby improving the handling properties of the curable resin composition.

[0045] In this embodiment, by including a structure represented by the above general formula (1) in the (meth)acrylic acid derivative, the aliphatic CH bond concentration is reduced, and absorption in the near-infrared region can be suppressed.

[0046] In order to achieve sufficient curability and handling properties of the curable resin composition, the mass ratio of the polysiloxane resin to the (meth)acrylic acid derivative is preferably in the range of 99:1 to 10:90, more preferably in the range of 90:10 to 10:90, and particularly preferably in the range of 80:20 to 20:80.

[0047] [(B) Method for producing (meth)acrylic acid derivatives] The method for producing the (meth)acrylic acid derivative in this embodiment is not particularly limited and can be produced by known and conventional methods.

[0048] For example, (meth)acrylic acid derivatives can be obtained by carrying out a dehydration condensation reaction between (meth)acrylic acid and a hydroxyl group-containing compound, or by carrying out a dehalogenation reaction between (meth)acrylic acid halide and a hydroxyl group-containing compound in the presence of a basic substance.

[0049] In the case of a dehydration condensation reaction, (meth)acrylic acid derivatives can be obtained by reacting an esterification catalyst such as p-toluenesulfonic acid or sulfuric acid with a polymerization inhibitor such as hydroquinone or phenothiazine, preferably in the presence of solvents (e.g., toluene, benzene, cyclohexane, n-hexane, n-heptane, etc.), preferably at a temperature of 70 to 150°C, using known methods. The proportion of (meth)acrylic acid used is 1 to 5 moles, preferably 1.05 to 2 moles, per 1 mole of the hydroxyl group-containing compound. The esterification catalyst is present at a concentration of 0.1 to 15 mol%, preferably 1 to 6 mol%, relative to the (meth)acrylic acid used.

[0050] Furthermore, in a dehalogenation reaction in the presence of a basic substance, (meth)acrylic acid derivatives can be obtained by reacting (meth)acrylic acid chloride with a hydroxyl group-containing compound, for example. In this case, it is preferable to add a basic substance such as triethylamine, pyridine, potassium hydroxide, or sodium hydroxide. In this case, it is preferable to add a phase transfer catalyst such as benzyltributylammonium chloride, tetrabutylammonium bromide, or benzyltriethylammonium chloride. (Meth)acrylic acid derivatives can be obtained by reacting (meth)acrylic acid chloride with a hydroxyl group-containing compound in the presence of a solvent (for example, toluene, benzene, cyclohexane, n-hexane, n-heptane, acetone, tetrahydrofuran, etc.) or water, preferably at a temperature of -10 to 100°C.

[0051] The hydroxyl group-containing compounds are not particularly limited, but examples include: hydroxybiphenyl; 2-phenylphenol, 3-phenylphenol, 4-phenylphenol; dihydroxybiphenyl; 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl, 2,5-dihydroxybiphenyl; phenylbenzyl alcohol; 3-phenylbenzyl alcohol, 4-phenylbenzyl alcohol; benzylphenol; 2-benzylphenol, 3-benzylphenol, 4-benzylphenol; bishydroxyphenylmethane; 4,4'-dihydroxydiphenyldiphenylmethane, 2,2'-dihydroxydiphenyldiphenylmethane, 2,4'-dihydroxydiphenyldiphenylmethane; hydroxydiphenylmethyl; diphenylmethanol; diphenylethanol; 1,1-diphenylethanol, 2,2-diphenylethanol, 1,1-diphenyl-1,2-ethanediol; phenoxyphenol; 2-phenoxyphenol, 3-phenoxyphenol, 4-phenoxyphenol; dihydroxydiphenyl ether; 4 ,4'-dihydroxydiphenyl ether, 2,2'-dihydroxydiphenyl ether, 2,4'-dihydroxydiphenyl ether, phenoxybenzyl alcohol; 2-phenoxybenzyl alcohol, 3-phenoxybenzyl alcohol, 4-phenoxybenzyl alcohol, phenylphenoxyethanol; 2-phenylphenoxyethanol, 3-phenylphenoxyethanol, 4-phenylphenoxyethanol, naphthol; 1-naphthol, 2-naphthol, dihydroxynaphthalene; 1,2-dihydroxynaphthalene, 1,3-dihydroxy Droxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, naphthalene methanol; 1-naphthalene methanol, 2-naphthalene methanol, naphthalenedimethanol; 1,4-naphthalenedimethanol, 1,5-naphthalenedimethanol, 1,8-naphthalenedimethanol, 2,3-naphthalenedimethanol, trishydroxyphenylmethyl;Examples include tris(4-hydroxyphenyl)methane, trishydroxyphenylethane, 1,3,5-tris(4-hydroxyphenyl)benzene, tetrakis(4-hydroxyphenyl)methane, tetrakishydroxyphenylethane; 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenylenedimethylenedynetetrakisphenol; α,α,α',α'-tetrakis(4-hydroxyphenyl)-p-xylene, α,α,α',α'-tetrakis(4-hydroxyphenyl)-m-xylene, 2,3,6,7,10,11-hexahydroxytriphenylene, and their isomers.

[0052] (C) Radical polymerization initiator In this embodiment, the radical polymerization initiator is not particularly limited as long as it initiates radical polymerization by heating or irradiation with active light such as ultraviolet light or visible light. Examples include thermal radical polymerization initiators and photoradical polymerization initiators.

[0053] Examples of photoradical polymerization initiators include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthones and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one.

[0054] Commercially available radical polymerization initiators include, for example, "Irgacure (registered trademark)-184", "Irgacure-149", "Irgacure-261", "Irgacure-369", "Irgacure-500", "Irgacure-651", "Irgacure-754", "Irgacure-784", "Irgacure-819", "Irgacure-907", "Irgacure-1116", "Irgacure-1664", "Irgacure-1700", "Irgacure-1800", "Irgacure-1850", "Irgacure-2959", "Irgacure-4043", "Irgacure-1173" (Chi Examples include "Lucilin TPO" (manufactured by Bas Specialty Chemicals), "KayaCure®-DETX", "KayaCure-MBP", "KayaCure-DMBI", "KayaCure-EPA", "KayaCure-OA" (manufactured by Nippon Kayaku Co., Ltd.), "Vycure-10", "Vycure-55" (manufactured by Stauffa Chemicals), "Trigonal P1" (manufactured by Akzo), "Sandoz 1000" (manufactured by Sandoz), "Deep" (manufactured by Apjohn), "Quantacure-PDO", "Quantacure-ITX", and "Quantacure-EPD" (manufactured by Ward Blenkinsop).

[0055] The radical polymerization initiator is preferably in the range of 0.05 to 20 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass, per 100 parts by mass of the curable resin composition, in order to exhibit sufficient curability.

[0056] <Other ingredients> Furthermore, so-called additives such as photosensitizers, antioxidants, surfactants, leveling agents, light stabilizers, and fillers may be added to the curable resin composition of this embodiment as needed, in proportions that do not adversely affect the effects of the present invention. It is preferable that the amount of components other than the essential components is 10 parts by mass or less per 100 parts by mass of the curable resin composition, as this results in particularly excellent effects of the present invention.

[0057] (Photosensitizer) When curing the curable resin composition of this embodiment by photopolymerization, various photosensitizers may be added in addition to the radical polymerization initiator. Examples of the photosensitizers include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, or other nitrogen-containing compounds, and these may be used individually or in combination of two or more. When adding these photosensitizers, the amount added is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the curable resin composition.

[0058] (Antioxidant) The curable resin composition of this embodiment may contain an antioxidant to improve heat resistance. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. When these antioxidants are added, the amount added is preferably in the range of 0.01 to 1 part by mass per 100 parts by mass of the curable resin composition.

[0059] (Surfactants) The curable resin composition of this embodiment may contain a surfactant to improve its applicability. Examples of such surfactants include fluorine-based surfactants, specifically perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl esters, perfluoroalkylamine oxides, and fluorine-containing organosiloxane compounds. When these surfactants are added, the amount added is preferably in the range of 0.01 to 1 part by mass per 100 parts by mass of the curable resin composition.

[0060] (Light stabilizer) As the aforementioned light stabilizer, commercially available products may be used, for example, TINUVIN® 123, 144, 152, 292, 770 [all manufactured by BASF Japan Ltd.], ADEKA Stab® LA-52, LA-57, LA-63P, LA-68, LA-72, LA-77Y, LA-77G, LA-81, LA-82, LA-87 [all manufactured by ADEKA Corporation], etc.

[0061] [Preparation of curable resin composition] The method for preparing the curable resin composition of this embodiment is not particularly limited as long as it is a method that ensures sufficient mixing, and generally, stirring with a stirring blade is preferred. The stirring time and stirring speed can be appropriately determined depending on the amount of each component blended, and from the viewpoint of ensuring sufficient mixing, the stirring time can be 1 to 24 hours and the stirring speed can be 10 to 1,000 rpm.

[0062] From the viewpoint of improving coatability and transparency, it is preferable to remove foreign matter from the curable resin composition using a filter. Furthermore, it is preferable to remove air bubbles from the curable resin composition using a degassing device such as a vacuum pump.

[0063] The curable resin composition preferably has a viscosity that is easy to handle, for example, in the range of 500 to 100,000 mPa·s at 25°C. Alternatively, it may be further diluted with an organic solvent as described later to adjust to a desired viscosity.

[0064] [Curing resin varnish] The curable resin composition of this embodiment may be diluted with an organic solvent to improve its applicability and used as a curable resin varnish. The organic solvent is not particularly limited as long as it can dissolve the curable resin composition, and examples include aromatic hydrocarbons, ethers, alcohols, ketones, esters, and amides. Specifically, examples include toluene, xylene, diethyl ether, dibutyl ether, tetrahydrofuran, 1,4-dioxane, methanol, ethanol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, γ-butyrolactone, ethylene carbonate, propylene carbonate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. These may be used individually or in combination of two or more.

[0065] The curable resin composition of this embodiment exhibits low light absorption loss, high UV curability, and excellent handling properties, making it suitable for use in components for photoelectric mixed-signal substrates, optical waveguides, right-angle high-path converters, optical pins, microlenses, spot size converters, optical shuffling sheets, optical converters, optical adhesives, and the like.

[0066] [Optical waveguide] Using the curable resin composition of this embodiment, a known and conventional method can be used to form an optical waveguide. Typically, an optical waveguide can be formed by forming a curable resin layer on a substrate, followed by exposure and development treatments.

[0067] The aforementioned substrate is not particularly limited and includes silicon wafers, glass wafers, quartz wafers, plastic circuit boards, ceramic circuit boards, and the like.

[0068] The curable resin layer can be formed by applying it to a substrate using methods such as spin coating, dip coating, spray coating, bar coating, roll coating, curtain coating, gravure coating, screen coating, or inkjet coating. The amount applied should be appropriately selected according to the purpose. When using the aforementioned curable resin varnish, a drying treatment may be performed after the curable resin layer is formed, if necessary.

[0069] When curing the aforementioned curable resin layer by exposure, the exposure amount is 0.01 to 10 J / cm². 2 It is preferable that the wavelength is within the above range. When it is within the above range, curing proceeds sufficiently and a delicate pattern can be formed. At this time, it is preferable to expose with light with a wavelength of 240 to 500 nm. Examples of light with a wavelength of 240 to 500 nm include light of various wavelengths generated by a radiation generator, such as ultraviolet rays such as g-rays and i-rays, and far ultraviolet rays (248 nm).

[0070] After exposure, the image is developed using a developer. The developer may be an organic solvent-based developer or an alkaline developer, and both may be used in combination.

[0071] Examples of the organic solvent-based developer include isopropyl alcohol, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate.

[0072] As the alkaline developer, for example, alkali metal hydroxides, alkali metal carbonates, alkali metal pyrophosphates, sodium salts, ammonium salts, and organic salts can be used as the base. [Examples]

[0073] The following examples of the present invention will be described in more detail, but the present invention is not limited to these examples.

[0074] [Evaluation Method] <Evaluation of light absorption loss> A curable resin composition was poured into a fluororubber O-ring placed on a glass plate, and then sandwiched between two glass plates to prevent air bubbles from being trapped. The mixture was then subjected to a nitrogen atmosphere and a high-pressure mercury lamp with an integrated light charge of 3000 mJ / cm². 2 The material was irradiated with a light source to harden it. The hardened material was peeled off the glass plate and O-ring to obtain a test piece with a diameter of 20 mm and a thickness of 5 mm. The absorbance of the above test specimen in the wavelength range of 400 to 2000 nm was measured using a UV-Vis-Near-Infrared Spectrophotometer (V-670) manufactured by JASCO Corporation. Since the decrease in light transmittance at 800 nm coincides with the reflected light intensity, the baseline was corrected so that the absorbance at 800 nm was zero, and the absorbance unaffected by reflection was calculated. The light absorption loss at 850 nm, 1310 nm, and 1550 nm was calculated using the following formula. Light absorption loss (dB / cm) = absorbance × 2 × 10 The optical absorption loss calculated from the above formula is preferably 0.1 or less at 850 nm. At 1310 nm, it is preferably 0.4 or less, and particularly preferably 0.2 or less. At 1550 nm, it is preferably 0.6 or less, and particularly preferably 0.4 or less.

[0075] <Heat resistance evaluation> Using a Rigaku Corporation TG-DTA apparatus (TG-8120), measurements were taken under a nitrogen flow of 20 mL / min and a heating rate of 20°C / min to determine the 5% weight loss temperature (Td5). The Td5 is preferably 300°C or higher, and particularly preferably 350°C or higher.

[0076] <Evaluation of weight-average molecular weight> The weight-average molecular weight was measured using the following measuring device and conditions. Measurement device: Tosoh Corporation "HLC-8320 GPC" Columns: Tosoh Corporation Guard Column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL" Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ Developing solvent: tetrahydrofuran Flow rate 1.0mL / min Standard: In accordance with the measurement manual for the aforementioned "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrenes with known molecular weights were used. (Uses polystyrene) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation Tosoh Corporation's "F-40" Tosoh Corporation's "F-80" Tosoh Corporation's "F-128"

[0077] (Manufacturing Example 1) In a 1 L flask equipped with a thermometer, condenser, and stirrer, 237.9 g (1.1 mol) of diphenylsilanediol, 124.2 g (0.5 mol) of 3-(methacryloyloxy)propyltrimethoxysilane, 99.1 g (0.5 mol) of phenyltrimethoxysilane, and 230.6 g of toluene were charged and heated to 50°C while stirring. Then, 0.37 g of barium hydroxide monohydrate was added and the mixture was reacted at 50°C for 20 hours. After the reaction was complete, the resulting reaction mixture was cooled to room temperature and filtered using a 0.2 μm pore size membrane filter. Toluene and the by-product methanol were removed under reduced pressure using a rotary evaporator. A polysiloxane resin (A1) with a weight-average molecular weight of 2900 and containing methacryloyl groups was obtained.

[0078] (Manufacturing example 2) The synthesis was carried out in the same manner as in Production Example 1, except that 124.2 g (0.5 mol) of 3-(methacryloyloxy)propyltrimethoxysilane in Production Example 1 was replaced with 117.2 g (0.5 mol) of 3-(acrylooxy)propyltrimethoxysilane, to obtain a polysiloxane resin (A2) having an acryloyl group and a weight-average molecular weight of 2900.

[0079] (Manufacturing Example 3) The synthesis was carried out in the same manner as in Production Example 1, except that 124.2 g (0.5 mol) of 3-(methacryloyloxy)propyltrimethoxysilane in Production Example 1 was replaced with 112.2 g (0.5 mol) of trimethoxy(4-vinylphenyl)silane, to obtain a polysiloxane resin (A3) having a styryl group and a weight-average molecular weight of 3000.

[0080] (Manufacturing example 4) In a 300 mL flask equipped with a thermometer, condenser, and stirrer, 27.63 g (0.10 ml) of bis(4-hydroxyphenyl)phenylmethane, 136.76 g of dichloromethane, and 24.29 g (0.24 ml) of triethylamine were charged, and the mixture was cooled to 0°C in an ice bath while stirring. Then, 21.72 g (0.24 ml) of acrylate chloride was added dropwise over 2 hours. The mixture was allowed to return to room temperature and reacted for a further 5 hours. After that, stirring was stopped, and the reaction mixture was washed once with 1% hydrochloric acid, once with saturated sodium bicarbonate aqueous solution, and twice with pure water. Subsequently, dichloromethane was removed from the reaction mixture under reduced pressure to obtain a liquid acrylic acid derivative (B1) represented by the following chemical formula. [ka]

[0081] (Manufacturing example 5) The synthesis was carried out in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was replaced with 29.04 g (0.10 mol) of 1,1-bis(4-hydroxyphenyl)-1-phenylethane, to obtain a liquid acrylic acid derivative (B2) represented by the following structural formula. [ka]

[0082] (Manufacturing example 6) The synthesis was carried out in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was replaced with 21.43 g (0.10 mol) of 1,1-bis(4-hydroxyphenyl)ethane, to obtain a semi-solid acrylic acid derivative (B3) represented by the following structural formula. [ka]

[0083] (Manufacturing example 7) The synthesis was carried out in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was replaced with 33.62 g (0.10 mol) of 2,2-bis(4-hydroxyphenyl)hexafluoropropane, to obtain a solid acrylic acid derivative (B4) represented by the following structural formula. [ka]

[0084] (Manufacturing example 8) The synthesis was carried out in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was replaced with 35.04 g (0.10 mol) of 9,9-bis(4-hydroxyphenyl)fluorene, to obtain a solid acrylic acid derivative (B5) represented by the following structural formula. [ka]

[0085] Using the polysiloxane resins (A1-A3) and acrylic acid derivatives (B1-B5) described above, and 2-hydroxy-2-methyl-1-phenylpropanone as a radical polymerization initiator (C), curable resin compositions were prepared and evaluated according to the formulations shown in Table 1. The units of the formulations in Table 1 are "parts by mass". In the table, "HMPP" means 2-hydroxy-2-methyl-1-phenylpropanone, "DVB" means divinylbenzene, and "BZA" means benzyl acrylate. The curable resin compositions obtained in Examples 1-5 were liquid and had excellent handling properties. Furthermore, the cured products obtained from the curable resin compositions of Examples 1-5 could all be sufficiently cured by UV irradiation.

[0086] In the comparative examples, no acrylic acid derivatives (B1-B5) were used at all. In Comparative Example 1, a curable resin composition was prepared in the same manner as in Example 1, except that 100 parts by mass of polysiloxane resin (A1) was used instead of acrylic acid derivative (B1). In Comparative Example 2, a curable resin composition was prepared in the same manner as in Example 1, except that divinylbenzene was used instead of acrylic acid derivative (B1). In Comparative Example 3, a curable resin composition was prepared in the same manner as in Example 1, except that benzyl acrylate was used instead of acrylic acid derivative (B1). The curable resin compositions obtained from Comparative Examples 1-3 were liquid and exhibited excellent handling properties, similar to Examples 1-5. Furthermore, the cured products obtained from the curable resin compositions of Comparative Examples 1-3 could be sufficiently cured by UV irradiation, similar to Examples 1-5.

[0087] [Table 1]

[0088] As shown in Table 1, the cured products obtained from the curable resin compositions of Examples 1 to 5 exhibit lower propagation loss in the 850-1550 nm wavelength range compared to the cured products obtained from the curable resin compositions of Comparative Examples 1 to 3, indicating lower absorption loss in the near-infrared region. Furthermore, the cured products obtained from the curable resin compositions of Examples 1 to 5 exhibit superior heat resistance, as evidenced by a higher 5% weight loss temperature Td5 compared to the cured products obtained from the curable resin compositions of Comparative Examples 1 to 3.

[0089] Based on these results, the cured products obtained by curing the curable resin compositions of Examples 1 to 5 are suitable for optical waveguide applications.

Claims

1. A curable resin composition containing the following components (A) to (C) as essential components. (A) A polysiloxane resin having one or more reactive groups selected from the group consisting of (meth)acryloyl groups and styryl groups. (B) One or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing the structure represented by the following general formula (1) 【Chemistry 13】 (In the above general formula (1), R １ and R ２ Each of these independently represents a hydrogen atom, a methyl group, a phenyl group, a naphthyl group, or a trifluoromethyl group, or R １ and R ２ This represents a cyclohexyl group to which a hydrogen atom is bonded, and the hydrogen atom bonded to the aromatic ring may optionally be replaced with a fluorine atom. (C) Radical polymerization initiator

2. The curable resin composition according to claim 1, wherein the (meth)acrylic acid derivative is a compound containing a structure represented by the following general formula (1), and the compound containing a structure represented by the following general formulas (1-1) to (1-4). 【Chemistry 14】

3. The curable resin composition according to claim 1 or 2, wherein the mass ratio of component (A) to component (B) is 99:1 to 10:

90.

4. The curable resin composition according to claim 1 or 2, wherein component (A) contains structural formulas represented by the following general formulas (2) and (3). 【Chemistry 15】 (In the above general formulas (2) and (3), R ３ R is an organic group having 1 to 12 carbon atoms. ４ and R ５ (Each of these independently represents either a methyl group or a phenyl group.)

5. The curable resin composition according to claim 4, wherein the molar ratio of general formula (2) to general formula (3) in component (A) is 1:0.9 to 1:1.

5.

6. A cured product obtained by curing the curable resin composition according to claim 1 or 2.

7. An optical waveguide comprising the cured product described in claim 6.

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