Curable resin composition, curable resin and cured product

Abstract

To provide a curable resin composition which enables obtaining of a cured product having excellent productivity (UV curability) in addition to low absorption (low optical absorption loss) in the near infrared region used in optical communication and excellent heat resistance.SOLUTION: A curable resin composition has as essential components, (A) a polysiloxane resin having one or more reactive groups selected from the group consisting of a (meth)acryloyl group and a styryl group, (B) one or more kinds of (meth)acrylic acid derivatives selected from the group consisting of compounds containing structures represented by general formula (1), and (C) a radical polymerization initiator. In the general formula (1), R1 and R2 each independently represents a hydrogen atom, a methyl group, a phenyl group, a naphthyl group and a trifluoromethyl group, or represents a cyclohexyl group and a fluorenyl group to which R1 and R2 are bonded.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition, a cured product obtained by curing the resin composition, and an optical waveguide, which are useful as optical waveguides, optical adhesives, transparent sealants, or related parts thereof that can be used in optical applications such as optical communication applications and optical integrated circuit applications. [Background technology]

[0002] In recent years, there has been an ever-increasing demand for faster and higher capacity communications and signal transmission. Optical signal transmission, instead of electrical, is also becoming increasingly important in the internal wiring of devices. This short-distance optical communication technology is called optical interconnect, and active development is underway on optical-electronic composite boards, which replace some of the copper electrical wiring on printed circuit boards with optical wiring using optical fiber or optical waveguides.

[0003] Required properties of materials used in optical waveguides include low absorption in the near-infrared region used in optical communications, excellent productivity, etc. Traditionally, quartz-based materials have been commonly used as materials for optical waveguides, but in recent years, there has been active research into optical waveguides made from polymer materials, which are low-cost and easy to process.

[0004] For example, fluorinated polyimides that can be used as optical materials for optical waveguides have been reported (Patent Document 1). However, although fluorinated polyimide-based materials have few CH groups in the molecule and have low absorption in the near-infrared region, they require baking at high temperatures, which can lead to problems such as cracks caused by stress resulting from the difference in linear expansion coefficient between the substrate and the film, and the need for reactive ion etching for patterning, which increases the number of steps and reduces productivity.

[0005] An organic / inorganic hybrid material having an organic reactive group and a siloxane skeleton has been reported as a material that can be patterned by photolithography and does not produce by-products (Patent Document 2). However, its absorption in the near-infrared region is not 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, so materials with excellent heat resistance are required. In particular, in recent years, lead-free solder with a high melting point has been used from the perspective of environmental issues, so there is an increasing 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 in optoelectronic composite substrates are typically sealed with transparent optical adhesives to enhance the reliability of the elements. For example, optical adhesives are used to connect light-emitting and receiving elements such as vertical cavity surface-emitting lasers (VCSELs) to optical waveguides on the substrate, followed by reflow soldering to connect the electrical wiring to the light-emitting and receiving elements and secure the elements in place. Therefore, such optical adhesives are required to have the same performance as materials used in optical waveguides.

[0008] To solve these problems, for example, a resin composition containing a liquid aliphatic epoxy compound and a specific aromatic epoxy compound (Patent Document 3) and a curable resin composition 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 improvement is required. [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 Application Publication No. 2020-184091 [Patent Document 4] Japanese Patent Application Publication No. 11-61081 Summary of the Invention [Problem to be solved by the invention]

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

[0011] The present inventors have conducted extensive research to solve the above problems, and as a result have found that a curable resin composition containing a specific (meth)acrylic acid derivative has low light absorption loss, high heat resistance, and excellent UV curability, which has led to the completion of the present invention.

[0012] That is, 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 a 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, or a trifluoromethyl group, or a cyclohexyl group or a 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 the above (1), wherein the (meth)acrylic acid derivative is a compound having a structure represented by the following general formula (1), and the compound having a structure represented by the following general formulas (1-1) to (1-5): [ka]

[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 a structural formula represented by the following general formulas (2) and (3): [ka] (In the above general formulas (2) and (3), R3 is 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 in the component (A), the molar ratio of the general formula (2) to the general formula (3) 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 described in (6) above. [Effects 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, it is possible to provide a curable resin composition that has low light absorption loss, high heat resistance, excellent UV curability, and also excellent handleability. DETAILED DESCRIPTION OF THE INVENTION

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

[0022] [Curable resin composition] The curable resin composition of the present 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, the reactive groups are particularly preferred from the viewpoint of UV curability. In this specification, the term "(meth)acryloyl group" refers to an acryloyl group or a methacryloyl group.

[0024] The polysiloxane resin may have at least one reactive group, and may have two or more, or may have three or more. For example, a (meth)acryloyl group is particularly excellent in UV curability, and a styryl group is particularly excellent in low light absorption loss, and is preferred. The ratio may be appropriately selected depending on the desired physical properties, and any one of the reactive groups may be contained alone or in combination, and is not particularly limited. From the viewpoint of UV curability, it is more preferred that the polysiloxane resin has one or more reactive groups, and particularly preferred that it has two or more.

[0025] In the polysiloxane resin, the concentration of the reactive group is preferably 500 to 10,000 mmol / kg, since sufficient curability can be obtained.

[0026] The polysiloxane resin of the present embodiment is not particularly limited as long as it has a siloxane skeleton, and examples thereof include 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-glycidoxypropyltriethoxysilane, Organotrialkoxysilanes such as silane, 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, and diphenyldichlorosilane, as well as tetraethoxysilane, tetramethoxysilane, diphenylsilanediol, di-p-tolylsilanediol, bis(4-ethylphenyl)silanediol, bis(4-isopropylphenyl)silanediol, dinaphthylsilanediol, bis([1,1' Examples include (4-vinylphenyl)silanediol, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, (4-isopropenylphenyl)trimethoxysilane, trimethoxy(4-vinyl-1-naphthyl)silane, trimethoxy(4'-vinyl-[1,1'-biphenyl]-4-yl)silane, and those obtained by complete or partial condensation of these. From the viewpoint of curability and flexibility, polysiloxane resins containing the structural formulas represented by the following general formulas (2) and (3) 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 each independently represent a methyl group or a phenyl group. The wavy line represents a bonding site.

[0028] Examples of the organic group having 1 to 12 carbon atoms in R3 include linear alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, and t-butyl; alkoxy groups such as methoxy and ethoxy; cyclic alkyl groups such as cyclohexyl and norbornanyl; alkenyl groups such as vinyl, 1-propenyl, allyl, butenyl, and 1,3-butadienyl; alkynyl groups such as ethynyl, propynyl, and butynyl; halogenated alkyl groups such as trifluoromethyl; alkyl groups having saturated heterocyclic groups such as 3-pyrrolidinopropyl; aryl groups such as phenyl, which may have an alkyl substituent; and aralkyl groups such as phenylmethyl and phenylethyl. The organic group may contain an oxygen atom or an amide bond between the carbon atoms, and may further contain a hydroxyl group, a halogen atom, a vinyl group, an epoxy group, a glycidoxypropyl group, a styryl group, or a (meth)acryloyloxypropyl group as a substituent.

[0029] In the polysiloxane resin, the molar ratio of the structural formulas represented by the general formulas (2) and (3) is preferably within the range of 1:0.9 to 1:1.5, and particularly preferably within the range of 1:1 to 1:1.4. When the molar ratio of the structural formula represented by the general formula (3) is 0.9 or more, the amount of hydroxyl groups in the polysiloxane resin can be suppressed, moisture absorption can be reduced, and absorption in the near-infrared region can be reduced. Furthermore, when the molar ratio of the structural formula represented by the general formula (3) is 1.5 or less, unreacted hydroxyl groups in the polysiloxane resin can be reduced and solidification of the polysiloxane resin can be suppressed, thereby improving handleability when preparing the curable resin composition, which is preferable.

[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. A molecular weight of 100,000 or less results in a curable resin composition that has good compatibility with the (meth)acrylic acid derivative described below and is also excellent in handleability, which is preferable. The weight-average molecular weight is a polystyrene-equivalent value measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as an elution solvent.

[0031] [(A) Method for producing polysiloxane resin] The method for producing the polysiloxane resin in this embodiment is not particularly limited, and any known and commonly used condensation reaction can be used. Methods for producing a polysiloxane resin containing the structural formula represented by the general formula (2) and the structural formula represented by the general formula (3) are shown below, but the method is not limited thereto.

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

[0033] Examples of the acidic catalyst include boric acid, trimethoxyboron, triethoxyboron, tri-n-propoxyboron, triisopropoxyboron, tri-n-butoxyboron, triisobutoxyboron, tri-sec-butoxyboron, tri-tert-butoxyboron, trimethoxyaluminum, triethoxyaluminum, tri-n-propoxyaluminum, triisopropoxyaluminum, tri-n-butoxyaluminum, triisobutoxyaluminum, tri-sec-butoxyaluminum, tri-tert-butoxyaluminum, tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, Examples of the acid 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, and trifluoromethanesulfonic acid.

[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] Of these catalysts, any one of magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, ammonium hydroxide and triethylamine is particularly preferred.

[0036] The amount of the catalyst used is preferably 0.001 to 10% by mass, and particularly preferably 0.01 to 1% by mass, based on the total mass of the compound containing the structural formula represented by the general formula (2) and the compound containing the structural formula represented by the general formula (3).Within this range, the condensation reaction proceeds satisfactorily, which is preferable.

[0037] The condensation reaction may be carried out in the absence or presence of a solvent, but is preferably carried out in the presence of a solvent to make the reaction system uniform. The reaction solvent may be any solvent that does not react with the raw materials, and examples thereof 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 alone or in combination. Among these, toluene is preferred.

[0038] Since the condensation reaction is a dealcoholization condensation reaction, it is preferably carried out in the absence of water, and is preferably carried out in an inert gas atmosphere such as nitrogen gas.

[0039] The reaction temperature may be adjusted appropriately to obtain a desired molecular weight distribution, and is usually 30 to 100° C. Similarly, the reaction time may be adjusted appropriately, but is usually 1 to 40 hours.

[0040] After the condensation reaction is complete, the resulting polysiloxane resin is filtered through a membrane filter, and the reaction solvent and by-product alcohol are removed under reduced pressure. It is also preferable to carry out a purification treatment as necessary.

[0041] <(B) (Meth)acrylic acid derivative> The (meth)acrylic acid derivative is characterized in that it is one or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing a 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, or a trifluoromethyl group, or a cyclohexyl group or a 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] The curable resin composition according to the present invention must contain a derivative represented by the general formula (1) as the (B) (meth)acrylic acid derivative, and preferably contains at least one derivative represented by the general formulas (1-1) to (1-5), but may contain two or more derivatives. Furthermore, the curable resin composition may contain, in addition to the derivatives represented by the general formulas (1-1) to (1-5), a (meth)acrylic acid derivative other than the derivatives represented by the general formulas (1-1) to (1-5).

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

[0045] In this embodiment, the (meth)acrylic acid derivative contains the structure represented by the above general formula (1), thereby reducing the aliphatic C—H bond concentration and suppressing absorption in the near-infrared region.

[0046] In order to achieve sufficient curability and handleability 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 the derivative can be produced by a known, commonly used method.

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

[0049] In the case of a dehydration condensation reaction, a (meth)acrylic acid derivative 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 a solvent (e.g., toluene, benzene, cyclohexane, n-hexane, n-heptane, etc.), preferably at a temperature of 70 to 150°C, using a known method. The proportion of (meth)acrylic acid used is 1 to 5 mol, preferably 1.05 to 2 mol, per mol of the hydroxy group-containing compound. The esterification catalyst is present at a concentration of 0.1 to 15 mol%, preferably 1 to 6 mol%, based on the (meth)acrylic acid used.

[0050] In addition, in a dehydrohalogenation reaction in the presence of a basic substance, for example, (meth)acrylic acid derivatives can be obtained by reacting (meth)acrylic acid chloride with a hydroxyl group-containing compound. 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. A (meth)acrylic acid derivative can be obtained by reacting (meth)acrylic acid chloride with a hydroxyl group-containing compound in the presence of a solvent (e.g., toluene, benzene, cyclohexane, n-hexane, n-heptane, acetone, tetrahydrofuran, etc.) or water, preferably at a temperature of −10 to 100° C.

[0051] The hydroxy group-containing compound is not particularly limited, and examples thereof 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'-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 Hydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, naphthalenemethanol; 1-naphthalenemethanol, 2-naphthalenemethanol, 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, phenylenedimethylenediaminetetrakisphenol; 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 the present embodiment, the radical polymerization initiator is not particularly limited as long as it initiates radical polymerization by heating or irradiation with actinic rays such as ultraviolet rays or visible light, and examples thereof include a thermal radical polymerization initiator and a photoradical polymerization initiator.

[0053] Examples of the photoradical polymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethan-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 products of these 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," and "Irgacure-1173" (Third Generation). Examples of suitable anti-inflammatory agents include BASF Specialty Chemicals, Lucirin TPO (manufactured by BASF), Kayacure (registered trademark)-DETX, Kayacure-MBP, Kayacure-DMBI, Kayacure-EPA, and Kayacure-OA (manufactured by Nippon Kayaku Co., Ltd.), Baycure-10, Baycure-55 (manufactured by Stauffer Chemical Co., Ltd.), Trigonal P1 (manufactured by Akzo), Sandray 1000 (manufactured by Sandoz), Deep (manufactured by Upjohn), Quantacure-PDO, Quantacure-ITX, and Quantacure-EPD (manufactured by Ward-Blenkinsop).

[0055] In order to achieve sufficient curability, the radical polymerization initiator is preferably used in an amount of 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the curable resin composition.

[0056] <Other ingredients> Furthermore, so-called additives such as a photosensitizer, an antioxidant, a surfactant, a leveling agent, a light stabilizer, and a filler may be added to the curable resin composition of the present embodiment, if necessary, in proportions that do not adversely affect the effects of the present invention. It is preferable that the components other than the essential components are 10 parts by mass or less relative to 100 parts by mass of the curable resin composition, since the effects of the present invention are particularly excellent.

[0057] (photosensitizer) When the curable resin composition of this embodiment is cured by photopolymerization, various photosensitizers may be added in addition to the radical polymerization initiator. Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles, and other nitrogen-containing compounds, and these may be used alone or in combination of two or more. When these photosensitizers are added, 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) An antioxidant may be added to the curable resin composition of this embodiment for the purpose of improving 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] (surfactant) A surfactant may be added to the curable resin composition of this embodiment to improve application properties. Examples of the surfactant include fluorine-based surfactants, specifically perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkyl amine oxide, 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) The light stabilizer may be a commercially available product, such as TINUVIN (registered trademark) 123, 144, 152, 292, and 770 (all manufactured by BASF Japan Ltd.), and Adeka STAB (registered trademark) LA-52, LA-57, LA-63P, LA-68, LA-72, LA-77Y, LA-77G, LA-81, LA-82, and LA-87 (all manufactured by ADEKA Corporation).

[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 can achieve sufficient mixing, and generally, stirring and mixing using a stirring blade is preferred. The stirring time and stirring speed can be determined appropriately depending on the blending amounts of the above-mentioned respective components, and from the viewpoint of ensuring sufficient mixing, the stirring time should be 1 to 24 hours and the stirring speed should be 10 to 1,000 rpm.

[0062] From the viewpoint of improving the coating property and the transparency, it is preferable to remove foreign matter from the curable resin composition using a filter. It is also preferable to remove bubbles from the curable resin composition using a defoaming 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. Furthermore, as described below, the composition may be further diluted with an organic solvent to adjust the viscosity to a desired level.

[0064] [Curable Resin Varnish] The curable resin composition of this embodiment may be diluted with an organic solvent to form a curable resin varnish for the purpose of improving coatability. The organic solvent is not particularly limited as long as it can dissolve the curable resin composition, and examples thereof include aromatic hydrocarbons, ethers, alcohols, ketones, esters, and amides. Specific 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 alone or in combination of two or more.

[0065] The curable resin composition of the present embodiment has low light absorption loss, high UV curability, and excellent handleability, and therefore can be suitably used for components used in opto-electric hybrid 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] The optical waveguide can be formed by using the curable resin composition of the present embodiment in a known, commonly used manner. Typically, the optical waveguide can be formed by forming a curable resin layer on a substrate, followed by exposure and development treatment.

[0067] The substrate is not particularly limited, and examples thereof include a silicon wafer, a glass wafer, a quartz wafer, a plastic circuit board, and a ceramic circuit board.

[0068] The curable resin layer can be formed by coating the substrate with a method such as spin coating, dip coating, spray coating, bar coating, roll coating, curtain coating, gravure coating, screen coating, or inkjet coating. The amount of coating may be appropriately selected depending on the purpose. When the curable resin varnish is used, the curable resin layer may be dried after formation, if necessary.

[0069] When the curable resin layer is cured by exposure, the exposure dose is 0.01 to 10 J / cm 2 Within this range, curing proceeds sufficiently, allowing for the formation of a fine pattern. In this case, it is preferable to perform exposure with light having a wavelength of 240 to 500 nm. Examples of light having 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 the exposure treatment, the film is developed using a developer, which may be an organic solvent-based developer or an alkaline developer, or a combination of these.

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

[0072] The alkaline developer may contain, as a base, for example, an alkali metal hydroxide, an alkali metal carbonate, an alkali metal pyrophosphate, a sodium salt, an ammonium salt, or an organic salt. [Example]

[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 optical absorption loss> The curable resin composition was poured into a fluororubber O-ring placed on a glass plate, and the plate was sandwiched between two glass plates from above to avoid trapping air bubbles. Under a nitrogen atmosphere, a high-pressure mercury lamp was used to illuminate the plate with an integrated light of 3000 mJ / cm. 2 The cured product was peeled off from the glass plate and the O-ring to obtain a test piece having a diameter of 20 mm and a thickness of 5 mm. The absorbance of the above test piece was measured in the wavelength range of 400 to 2000 nm using a JASCO V-670 ultraviolet-visible-near-infrared spectrophotometer. Because the decrease in light transmittance at 800 nm corresponds to the reflected light intensity, the baseline was corrected so that the absorbance at 800 nm was zero, and the absorbance without the influence of reflection was calculated. The light absorption loss at 850 nm, 1310 nm, and 1550 nm was calculated using the following formula. Optical 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, preferably 0.4 or less, and particularly preferably 0.2 or less, at 1310 nm, and preferably 0.6 or less, and particularly preferably 0.4 or less, at 1550 nm.

[0075] <Evaluation of heat resistance> The 5% weight loss temperature (Td5) was measured using a TG-DTA apparatus (TG-8120) manufactured by Rigaku Corporation under a nitrogen flow of 20 mL / min at a temperature increase rate of 20°C / min. 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 under the following measuring conditions. Measuring device: Tosoh Corporation "HLC-8320 GPC" Column: 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°C Developing solvent: Tetrahydrofuran Flow rate 1.0mL / min Standard: The following monodisperse polystyrenes with known molecular weights were used in accordance with the measurement manual for the GPC Workstation EcoSEC-WorkStation. (Polystyrene used) Tosoh Corporation "A-500" Tosoh Corporation "A-1000" Tosoh Corporation "A-2500" Tosoh Corporation "A-5000" "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation "F-40" manufactured by Tosoh Corporation "F-80" manufactured by Tosoh Corporation Tosoh Corporation "F-128"

[0077] (Production Example 1) A 1 L flask equipped with a thermometer, condenser, and stirrer was charged with 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, and the mixture was heated to 50°C with 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 membrane filter. The toluene and 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] (Production Example 2) 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 changed to 117.2 g (0.5 mol) of 3-(acryloxy)propyltrimethoxysilane, to obtain a polysiloxane resin (A2) having an acryloyl group and a weight average molecular weight of 2900.

[0079] (Production Example 3) A polysiloxane resin (A3) having a styryl group and a weight average molecular weight of 3,000 was obtained by synthesis 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 changed to 112.2 g (0.5 mol) of trimethoxy(4-vinylphenyl)silane.

[0080] (Production Example 4) A 300 mL flask equipped with a thermometer, condenser, and stirrer was charged with 27.63 g (0.10 mol) of bis(4-hydroxyphenyl)phenylmethane, 136.76 g of dichloromethane, and 24.29 g (0.24 mol) of triethylamine, and cooled to 0°C in an ice bath while stirring. Then, 21.72 g (0.24 mol) of acrylic acid chloride was added dropwise over 2 hours. The mixture was returned to room temperature and allowed to react for an additional 5 hours. Then, stirring was stopped, and the reaction solution was washed once with 1% hydrochloric acid, once with saturated aqueous sodium bicarbonate, and twice with pure water. Dichloromethane was then removed from the reaction solution by distillation under reduced pressure, yielding a liquid acrylic acid derivative (B1) represented by the following chemical formula: [ka]

[0081] (Production Example 5) A liquid acrylic acid derivative (B2) represented by the following structural formula was obtained by synthesis in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was changed to 29.04 g (0.10 mol) of 1,1-bis(4-hydroxyphenyl)-1-phenylethane. [ka]

[0082] (Production Example 6) A semi-solid acrylic acid derivative (B3) represented by the following structural formula was obtained by synthesis in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was changed to 21.43 g (0.10 mol) of 1,1-bis(4-hydroxyphenyl)ethane. [ka]

[0083] (Production Example 7) A solid acrylic acid derivative (B4) represented by the following structural formula was obtained by synthesis in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was changed to 33.62 g (0.10 mol) of 2,2-bis(4-hydroxyphenyl)hexafluoropropane. [ka]

[0084] (Production Example 8) A solid acrylic acid derivative (B5) represented by the following structural formula was obtained by synthesis in the same manner as in Production Example 4, except that 27.63 g of bis(4-hydroxyphenyl)phenylmethane in Production Example 4 was changed to 35.04 g (0.10 mol) of 9,9-bis(4-hydroxyphenyl)fluorene. [ka]

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

[0086] In the comparative examples, no acrylic acid derivatives (B1 to 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 no acrylic acid derivative (B1) was used and 100 parts by mass of polysiloxane resin (A1) was used. 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 the 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 the acrylic acid derivative (B1). The obtained curable resin compositions of comparative examples 1 to 3 were liquid and had excellent handleability, similar to examples 1 to 5. Furthermore, the cured products obtained from the curable resin compositions of comparative examples 1 to 3 could be sufficiently cured by UV irradiation, similar to examples 1 to 5.

[0087] [Table 1]

[0088] As shown in Table 1, the cured products obtained from the curable resin compositions of Examples 1 to 5 have smaller propagation losses in the wavelength range of 850 to 1550 nm, indicating that they have lower absorption losses in the near-infrared region, compared to the cured products obtained from the curable resin compositions of Comparative Examples 1 to 3. Furthermore, the cured products obtained from the curable resin compositions of Examples 1 to 5 have higher 5% weight loss temperatures Td5, indicating that they have superior heat resistance, compared to the cured products obtained from the curable resin compositions of Comparative Examples 1 to 3.

[0089] From the above results, the cured products obtained by curing the curable resin compositions of Examples 1 to 5 are suitable for use as optical waveguides.

Claims

1. A curable resin composition comprising 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 a (meth)acryloyl group and a styryl group; (B) One or more (meth)acrylic acid derivatives selected from the group consisting of compounds containing a structure represented by the following general formula (1): 【Chemistry 1】 (In the above general formula (1), R １ and R ２ each independently represents a hydrogen atom, a methyl group, a phenyl group, a naphthyl group, or a trifluoromethyl group, or R １ and R ２ is bonded to a cyclohexyl group or a fluorenyl group, and a hydrogen atom bonded to the aromatic ring may be optionally substituted 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 having a structure represented by the following general formula (1): 【Chemistry 2】

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

90.

4. The curable resin composition according to claim 1 or 2, wherein the component (A) has a structural formula represented by the following general formulas (2) and (3): 【Transformation 3】 (In the above general formulas (2) and (3), R ３ is an organic group having 1 to 12 carbon atoms, R ４ and R ５ each independently represents a methyl group or a phenyl group.

5. The curable resin composition according to claim 4, wherein in the component (A), the molar ratio of the general formula (2) to the general formula (3) 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 according to claim 6 .

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