JP2011116798A - Resin composition for forming optical waveguide and optical waveguide-forming resin film using the same, and optical waveguide using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for optical waveguides, which enables to form optical waveguides excellent in transparency, thermal reflow resistance, heat shock resistance, environmental reliability, and lamination stability in good productivity and workability, to provide a resin film for forming optical waveguides, to provide an optical waveguide-forming resin excellent in storage stability and alkali developability, and to provide an optical waveguide-forming film. <P>SOLUTION: There are provided the resin composition for forming optical waveguides, comprising (A) a carboxyl group-having polymer, (B) an ethylenic unsaturated group-having compound, (C) a compound having two or more epoxy groups in the molecule and having an epoxy equivalent of 250 to 1,000 g/eq, and (D) a radical polymerization initiator; the optical waveguide-forming resin film using the resin composition; and the optical waveguide using the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a resin composition for forming an optical waveguide, a resin film for forming an optical waveguide, and an optical waveguide using these, and in particular, a resin composition for forming an optical waveguide having excellent transparency and heat resistance, and the formation of the optical waveguide. The present invention relates to a resin film for forming an optical waveguide using a resin composition for an optical waveguide, and an optical waveguide excellent in transparency, reliability, and heat resistance using the same.

In high-speed and high-density signal transmission between electronic devices and between wiring boards, signal transmission interference and attenuation become barriers in conventional transmission using electric wiring, and the limits of high speed and high density are beginning to appear. In order to overcome this, development of a technique for connecting electronic elements and wiring boards with light, a so-called optical interconnection technique, has been underway. As an optical transmission line, polymer optical waveguides are attracting attention because of their ease of processing, low cost, high degree of freedom in wiring, and high density.
As the form of the polymer optical waveguide, a rigid optical waveguide produced on a hard support substrate such as a glass epoxy resin that is assumed to be applied to an opto-electric hybrid substrate, or a flexible optical device that does not have a rigid support substrate that assumes connection between boards Waveguides are considered suitable.
Furthermore, by using an opto-electric composite flexible wiring board in which a flexible wiring board and an optical waveguide are integrally combined, the degree of mounting freedom can be further improved.

Polymer optical waveguides are required to have heat resistance and environmental reliability as well as transparency (low light propagation loss) from the viewpoint of the environment in which the equipment is used and component mounting. In addition, regarding an optical waveguide manufacturing process, a method capable of easily forming a core pattern is required, and one of the methods is a pattern forming method by exposure and development widely used in a printed wiring board manufacturing process. be able to. Among them, a pattern formation method by a development process using an alkali developer as a developer (hereinafter sometimes abbreviated as alkali development) is preferable from the viewpoint of safety and environmental load, and an optical waveguide material that can cope with the alkali development process. The demand for is increasing. As such a material, an optical waveguide material containing a (meth) acrylic polymer having a carboxyl group (for example, see Patent Documents 1 to 3) is known.
However, although the optical waveguide material described in Patent Document 1 can form a core pattern by alkali development and has transparency at a wavelength of 850 nm, the optical waveguide material is specifically evaluated for heat resistance, for example, light propagation loss after a solder reflow test. There is no specific description of the test results and it is not clear. Similarly, there is no specific description of specific test results such as evaluation of environmental reliability, for example, light transmission loss after a high temperature and high humidity storage test or a temperature cycle test, and it is not clear.
Moreover, although the optical waveguide material described in Patent Document 2 has transparency at a wavelength of 850 nm and has good light propagation loss after a high-temperature and high-humidity standing test, it is evaluated for heat resistance, for example, after a solder reflow test. There is no specific description about specific test results such as light propagation loss, and it is not clear.
Moreover, although the optical waveguide material described in Patent Document 3 exhibits excellent optical transmission loss and has good solder heat resistance and reflow heat resistance, the storage stability is not satisfactory.
Patent Document 4 is excellent in reflow heat resistance and transparency using a resin composition for forming an optical waveguide containing a maleimide skeleton in the main chain and an alkali-soluble (meth) acrylic polymer, a polymerizable compound, and a polymerization initiator. It is disclosed that an optical waveguide can be manufactured.

Japanese Patent Laid-Open No. 06-258537 JP 2008-33239 A JP 2006-71880 A Japanese Patent No. 4241899

In recent years, in the process of manufacturing an opto-electric composite flexible wiring board, in the step of bonding an electric wiring board and an optical waveguide using an adhesive, for example, heat treatment is performed under conditions of 180 ° C. and 1 hour, When the heat treatment was performed under the above conditions, the problem that the transparency was lowered was revealed. Therefore, it is required to have stability against heat (stability at the time of bonding) when the optical waveguide material is heat-treated at 180 ° C. for about 1 hour.
Therefore, in view of the above-described problems, the present invention provides a resin composition for an optical waveguide capable of forming an optical waveguide excellent in transparency, reflow heat resistance, thermal shock resistance, environmental reliability, and stability at the time of bonding with good productivity and workability. It is an object to provide a product and a resin film for forming an optical waveguide.
Moreover, according to this invention, the resin for optical waveguide formation and the film for optical waveguide formation excellent in storage stability and alkali developability are provided.

  As a result of extensive studies, the present inventors have found that a resin composition for forming an optical waveguide containing a polymer having a carboxyl group, a compound having an ethylenically unsaturated group, and a radical polymerization initiator, and two or more in the molecule. The present inventors have found that the above-mentioned problems can be solved by using a compound having an epoxy group and having an epoxy equivalent of 250 to 1,200 g / eq.

  That is, the present invention includes (A) a polymer having a carboxyl group, (B) a compound having an ethylenically unsaturated group, (C) having two or more epoxy groups in the molecule, and an epoxy equivalent of 250 to 1000 g. / Eq compound, and (D) a resin composition for forming an optical waveguide containing a radical polymerization initiator, an optical waveguide forming resin film using the resin composition for forming an optical waveguide, a lower cladding layer, a core part, Transparency, reflow heat resistance, thermal shock resistance, environmental reliability, stable at the time of bonding, wherein at least one of the upper cladding layers is formed using the optical waveguide forming resin composition or the optical waveguide forming resin film An optical waveguide having excellent properties is provided.

  According to the present invention, transparency, reflow heat resistance, stability at the time of bonding are excellent, high-precision thick film formation and alkali development are possible, and it is effective for manufacturing an optical waveguide, and produces an optical waveguide. In this case, a resin composition for forming an optical waveguide useful for a resin film for forming an optical waveguide having high storage stability and productivity can be provided. Also provided are a resin film for forming an optical waveguide using the resin composition for forming an optical waveguide, and an optical waveguide having excellent transparency, reflow heat resistance, thermal shock resistance, environmental reliability, and stability at the time of bonding. Can do.

It is sectional drawing explaining the form of the optical waveguide of this invention. The temperature profile in the reflow furnace in the reflow test implemented by this invention is shown.

(Resin composition for optical waveguide formation)
The resin composition for forming an optical waveguide of the present invention comprises (A) a polymer having a carboxyl group, (B) a compound having an ethylenically unsaturated group, (C) having two or more epoxy groups in the molecule, and It includes a compound having an epoxy equivalent of 250 to 1000 g / eq, and (D) a radical polymerization initiator.
In the following description, “heat resistance” is used to mean both reflow heat resistance and stability during bonding unless otherwise specified.

((A) Polymer having carboxyl group)
(A) There is no restriction | limiting in particular as a polymer which has a carboxyl group, For example, the polymer etc. which are represented by following (1)-(6) are mentioned.
(1) A polymer obtained by copolymerizing a compound having a carboxyl group and an ethylenically unsaturated group in the molecule with another compound having an ethylenically unsaturated group.
(2) Partially introducing an ethylenically unsaturated group into the side chain into a copolymer of a compound having a carboxyl group and an ethylenically unsaturated group in the molecule and another compound having an ethylenically unsaturated group Obtained polymer.
(3) A compound having a carboxyl group and an ethylenically unsaturated group in the molecule as a copolymer of a compound having an epoxy group and an ethylenically unsaturated group in the molecule and another compound having an ethylenically unsaturated group. And a polymer obtained by reacting a polybasic acid anhydride with the generated hydroxyl group.
(4) A compound having an hydroxyl group and an ethylenically unsaturated group in the molecule is reacted with a copolymer of an acid anhydride having an ethylenically unsaturated group and another compound having an ethylenically unsaturated group. The resulting polymer.
(5) A polymer obtained by reacting a polybasic acid anhydride with a hydroxyl group of a copolymer of a bifunctional epoxy resin and a dicarboxylic acid and / or a bifunctional phenol compound.
(6) A polymer obtained by reacting a polybasic acid anhydride with a hydroxyl group of a copolymer of a bifunctional oxetane compound and a dicarboxylic acid and / or a bifunctional phenol compound.

  Among these, from the viewpoint of transparency and solubility in an alkali developer, the polymer having a carboxyl group represented by the above (1) to (4) is preferable, and represented by the following general formulas (1) and (2). (Meth) acrylic polymer having a structural unit is more preferred.

In the formula, each R ¹ independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R ² represents a hydrogen atom or a methyl group. As the monovalent organic group having 1 to 20 carbon atoms represented by R ^1, is not particularly limited, for example, an alkyl group means a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group (-CO-R Where R is a hydrocarbon group), an ester group (means —CO—O—R or —O—CO—R, where R is a hydrocarbon group), a monovalent organic group such as a carbamoyl group. These may further include a hydroxyl group, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group, a formyl group, an ester group, an amide group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, It may be substituted with an amino group, a silyl group, a silyloxy group, or the like.
Among these, an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group are preferable from the viewpoints of transparency and heat resistance.

In the formula, X ¹ represents a single bond or a divalent organic group having 1 to 20 carbon atoms. As the divalent organic group having 1 to 20 carbon atoms represented by X ^1, not particularly limited, for example, an alkylene group, a cycloalkylene group, a phenylene group, a biphenylene group, a polyether group, a polysiloxane group, a carbonyl group Divalent organic groups including an ester group, an amide group, a urethane group, and the like, which further include a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group, a formyl group, an ester group, It may be substituted with an amide group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a silyl group, a silyloxy group, or the like.
Among these, an alkylene group, a cycloalkylene group, a phenylene group, and a biphenylene group are preferable from the viewpoint of transparency and heat resistance.

In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a monovalent organic group having 1 to 20 carbon atoms. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

  The (meth) acrylic polymer refers to a polymer obtained by copolymerizing monomers having a (meth) acryloyl group such as acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, and derivatives thereof. Here, the (meth) acryloyl group means an acryloyl group and / or a methacryloyl group. Further, it may be a copolymer containing the above monomer and, if necessary, a monomer other than the above having an ethylenically unsaturated group other than the (meth) acryloyl group as long as the effect of the present invention is not impaired. . Further, it may be a mixture of a plurality of (meth) acrylic polymers.

  In the (meth) acrylic polymer, the compound as a raw material for the structural unit represented by the general formula (1) is not particularly limited, and examples thereof include (meth) acrylic acid, crotonic acid, cinnamic acid, maleic acid, Fumaric acid, citraconic acid, mesaconic acid, itaconic acid, mono (2- (meth) acryloyloxyethyl) succinate, mono (2- (meth) acryloyloxyethyl) phthalate, mono (2- (meth) acryloyloxyethyl) iso Phthalate, mono (2- (meth) acryloyloxyethyl) terephthalate, mono (2- (meth) acryloyloxyethyl) tetrahydrophthalate, mono (2- (meth) acryloyloxyethyl) hexahydrophthalate, mono (2- (meta ) Acrylyloxyethyl) hexahydroisophthalate, (2- (meth) acryloyloxyethyl) hexahydroterephthalate, .omega.-carboxy - polycaprolactone mono (meth) acrylate, 3-vinylbenzoic acid, 4-vinylbenzoic acid.

Among these, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, mono (2- (meth) acryloyloxyethyl) succinate, mono from the viewpoint of transparency, heat resistance, and solubility in an alkali developer. (2- (meth) acryloyloxyethyl) tetrahydrophthalate, mono (2- (meth) acryloyloxyethyl) hexahydrophthalate, mono (2- (meth) acryloyloxyethyl) hexahydroisophthalate, mono (2- (meta Preferably it is () acryloyloxyethyl) hexahydroterephthalate.
In addition, a compound having an ethylenically unsaturated group and an acid anhydride group such as maleic anhydride, citraconic anhydride, and itaconic anhydride is used as a raw material, and after the copolymerization, the ring is opened with an appropriate alcohol such as methanol, ethanol, or propanol. However, it may be converted into a structural unit represented by the general formula (1).
These compounds can be used alone or in combination of two or more.

  In the (meth) acrylic polymer, the content of the structural unit represented by the general formula (1) is preferably 5 to 60 mol%. When the amount is 5 mol% or more, the solubility in an alkali developer is good, and when the amount is 60 mol% or less, the developer resistance (the portion that becomes a pattern without being removed by development is not affected by the developer). Good properties). From the above viewpoint, the content of the structural unit represented by the general formula (1) is more preferably 10 to 50 mol%, and particularly preferably 15 to 40 mol%.

  In the (meth) acrylic polymer, the compound used as a raw material for the structural unit represented by the general formula (2) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) Acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl (meth) acrylate, pentyl (meth) acrylate, hexyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl heptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, Uril (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, methoxypolypropylene Aliphatic (meth) acrylates such as glycol (meth) acrylate and ethoxypolypropylene glycol (meth) acrylate; Cycloaliphatic (meth) acrylates such as (meth) acrylate, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate; phenyl (Meth) acrylate, benzyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) ) Acrylate, o-phenylphenoxyethyl (meth) acrylate, 1-naphthoxyethyl (meth) acrylate, 2-naphthoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate Acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3- (o-phenylphenoxy) propyl (meth) acrylate, Aromatic (meth) acrylates such as 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate and 2-hydroxy-3- (2-naphthoxy) propyl (meth) acrylate; 2-tetrahydrofurfuryl (meth) Examples thereof include heterocyclic (meth) acrylates such as acrylate, N- (meth) acryloyloxyethyl hexahydrophthalimide, and 2- (meth) acryloyloxyethyl-N-carbazole.

Among these, from the viewpoint of transparency and heat resistance, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate Aliphatic (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; the alicyclic (meth) acrylate; the aromatic (meta ) Acrylate; preferably the heterocyclic (meth) acrylate.
These compounds can be used alone or in combination of two or more.

  In the (meth) acrylic polymer, the content of the structural unit represented by the general formula (2) is preferably 40 to 95 mol%. When it is 40 mol% or more, the developer resistance is good, and when it is 95 mol% or less, the solubility in an alkali developer is good. From the above viewpoint, the content of the structural unit represented by the general formula (2) is more preferably 50 to 90 mol%, and particularly preferably 60 to 85 mol%.

  The (meth) acrylic polymer may further have a structural unit derived from a maleimide skeleton represented by the general formula (3) as necessary from the viewpoint of heat resistance.

In the formula, R ⁵ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In the (meth) acrylic polymer, there are no particular limitations on the compound used as a raw material for the structural unit derived from the maleimide skeleton represented by the general formula (3). For example, N-methylmaleimide, N-ethylmaleimide, N- Propylmaleimide, N-isopropylmaleimide, N-2,2-dimethylpropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-sec-butylmaleimide, N-tert-butylmaleimide, N-2-methyl-2- Butylmaleimide, N-pentylmaleimide, N-2-pentylmaleimide, N-3-pentylmaleimide, N-hexylmaleimide, N-2-hexylmaleimide, N-3-hexylmaleimide, N-2-ethylhexylmaleimide, N- Heptylmaleimide, N-octylmaleimide, N -Alkyl maleimides such as nonyl maleimide, N-decyl maleimide, N-hydroxymethyl maleimide, N-2-hydroxyethyl maleimide, N-2-hydroxypropyl maleimide; N-cyclopentyl maleimide, N-cyclohexyl maleimide, N-cycloheptyl maleimide N-cyclooctylmaleimide, N-2-methylcyclohexylmaleimide, N-2-ethylcyclohexylmaleimide, N-2-chlorocyclohexylmaleimide and other cycloalkylmaleimides; N-phenylmaleimide, N-2-methylphenylmaleimide, N Examples thereof include arylmaleimides such as 2-ethylphenylmaleimide, N-2-chlorophenylmaleimide, and N-benzylmaleimide.
Among these, from the viewpoints of transparency and heat resistance, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-sec-butylmaleimide, Alkyl maleimides such as N-tert-butylmaleimide; cycloalkylmaleimides; arylmaleimides are preferably used, and N-cyclopentylmaleimide, N-cyclohexylmaleimide, N-2-methylcyclohexylmaleimide, N-phenylmaleimide, N- More preferred is benzylmaleimide.
These compounds can be used alone or in combination of two or more.

  When the (meth) acrylic polymer has a structural unit derived from a maleimide skeleton represented by the general formula (3), the content is preferably 1 to 60 mol%. When it is 1 mol% or more, heat resistance derived from the maleimide skeleton is obtained, and when it is 60 mol% or less, the transparency is sufficient and the obtained cured product does not become brittle. From the above viewpoint, the content of the structural unit derived from the maleimide skeleton represented by the general formula (3) is more preferably 3 to 50 mol%, and particularly preferably 5 to 40 mol%.

The (meth) acrylic polymer may further have a structural unit other than the structural units represented by the general formulas (1) to (3) as necessary.
There is no restriction | limiting in particular as a compound which has an ethylenically unsaturated group used as the raw material of such a structural unit, For example, styrene, alpha-methylstyrene, beta-methylstyrene, 3-methylstyrene, 4-methylstyrene, alpha , 2-dimethylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, (meth) acrylonitrile, vinyl cyclohexyl ether, vinyl phenyl ether, vinyl benzyl ether, vinyl acetate, N-vinyl pyrrolidone, N-vinyl carbazole, Examples include vinyl pyridine, vinyl chloride, vinylidene chloride.
Among these, from the viewpoints of transparency and heat resistance, styrene, α-methylstyrene, β-methylstyrene, 3-methylstyrene, 4-methylstyrene, α, 2-dimethylstyrene, 2,4-dimethylstyrene, 2, 5-dimethylstyrene, (meth) acrylonitrile, vinyl acetate, and N-vinylcarbazole are preferred.
These compounds can be used alone or in combination of two or more.

  The synthesis method of the (meth) acrylic polymer is not particularly limited. For example, the compound used as a raw material of the structural unit represented by the general formulas (1) and (2), and if necessary, the general formula (3) A compound serving as a raw material for a structural unit derived from a maleimide skeleton represented by formula (1), a compound serving as a raw material for a structural unit other than the structural units represented by the general formulas (1) to (3), and a suitable thermal radical polymerization initiator Can be obtained by copolymerization while heating. At this time, if necessary, an organic solvent and / or water can be used as a reaction solvent. Moreover, it can also be used in combination with an appropriate chain transfer agent, dispersant, surfactant, emulsifier and the like as required.

  The thermal radical polymerization initiator is not particularly limited, and examples thereof include ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1 -Bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane Peroxyketals such as 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane; hydroperoxides such as p-menthane hydroperoxide; α, α′-bis (t-butyl Peroxy) diisopropylbenzene, dicumyl peroxide, t- Dialkyl peroxides such as butylcumyl peroxide and di-t-butyl peroxide; diacyl peroxides such as octanoyl peroxide, lauroyl peroxide, stearyl peroxide and benzoyl peroxide; bis (4-t-butylcyclohexyl) peroxide Peroxycarbonates such as oxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-3-methoxybutyl peroxycarbonate; t-butyl peroxypivalate, t- Hexyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t -Hexilpa Oxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropylmonocarbonate, t-butylperoxy-3,5 5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, Peroxyesters such as 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane and t-butylperoxyacetate; 2,2′-azobisisobutyronitrile, 2,2′-azobis (2 , 4-Dimethylvaleronitrile), 2,2′- Zobisu (4-methoxy-2'-dimethylvaleronitrile) azo compounds and the like.

The organic solvent used as the reaction solvent is not particularly limited as long as it can dissolve the (meth) acrylic polymer. For example, aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, p-cymene; Chain ethers such as diethyl ether, tert-butyl methyl ether, cyclopentyl methyl ether, and dibutyl ether; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, γ Esters such as butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Polyhydric alcohol alkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether Polyhydric alcohol alkyl ethers such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Acetates; amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and the like.
These organic solvents can be used alone or in combination of two or more.

The weight average molecular weight of the component (A) is preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ . When 1.0 × 10 ³ or more, the molecular weight is large, the strength of the cured product when the resin composition is obtained is sufficient, and when it is 1.0 × 10 ⁶ or less, solubility in the developer and (B) Good compatibility with the polymerizable compound. From the above viewpoints, the (A) The weight average molecular weight of the component is more preferably ^{3.0 × 10 3 ~5.0 × 10 5} , at 5.0 × 10 ³ ~3.0 × 10 ⁵ It is particularly preferred.
The weight average molecular weight in the present invention is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

  The component (A) can have an acid value so that it can be developed with an alkali developer described later. For example, when an aqueous alkaline developer composed of an aqueous alkaline solution is used as the alkaline developer, the acid value is preferably 30 to 250 mgKOH / g. When it is 30 mgKOH / g or more, the solubility in an alkali developer is good, and when it is 250 mgKOH / g or less, the developer resistance is good. From the above viewpoint, the acid value of the component (A) is more preferably 35 to 200 mgKOH / g, and particularly preferably 40 to 170 mgKOH / g.

  Moreover, when using the semi-aqueous type alkali developing solution which consists of aqueous alkali solution and 1 or more types of organic solvent as an alkali developing solution, it is preferable that an acid value is 20-200 mgKOH / g. When the acid value is 20 mgKOH / g or more, the solubility in an alkali developer is good, and when it is 200 mgKOH / g or less, the developer resistance is good. From the above viewpoint, the acid value of the component (A) is more preferably 25 to 170 mgKOH / g, and particularly preferably 30 to 150 mgKOH / g.

  The blending amount of the component (A) is preferably 30 to 85% by mass with respect to the total amount of the components (A) to (C). When it is 30% by mass or more, the solubility in an alkali developer is good, and when it is 85% by mass or less, it is sufficiently entangled and cured by the component (B) at the time of photocuring. Is good. From the above viewpoint, the blending amount of the component (A) is more preferably 35 to 80% by mass, and particularly preferably 40 to 75% by mass.

((B) Compound having an ethylenically unsaturated group)
(B) There is no restriction | limiting in particular as a compound which has an ethylenically unsaturated group, For example, ethylene, such as (meth) acrylate, vinyl ether, vinyl ester, vinylamide, arylated vinyl, vinylpyridine, vinyl halide, vinylidene halide, etc. And compounds having a polymerizable substituent such as a polymerizable unsaturated group.
Among these, (meth) acrylate and arylated vinyl are preferable from the viewpoint of transparency and heat resistance.
As the (meth) acrylate, any of monofunctional, bifunctional, or trifunctional or higher can be used.

  There is no restriction | limiting in particular as monofunctional (meth) acrylate, For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) Acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate , Octyl heptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate Tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, behenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3- Chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, ethoxypolypropylene glycol (meth) Acrylates, aliphatic (meth) acrylates such as mono (2- (meth) acryloyloxyethyl) succinate, etc. , Their propoxylated compounds, their ethoxylated propoxylated compounds, and their caprolactone modified products; cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meta ) Acrylate, isobornyl (meth) acrylate, mono (2- (meth) acryloyloxyethyl) tetrahydrophthalate, mono (2- (meth) acryloyloxyethyl) hexahydrophthalate, etc., ethoxy of these , These propoxylated compounds, these ethoxylated propoxylated compounds, and their caprolactone modified products; phenyl (meth) acrylate, benzyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-na Butyl (meth) acrylate, 2-naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, o-phenylphenoxyethyl (meth) acrylate, 1-naphthoxyethyl (meth) acrylate, 2-naphthoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy- 3- (o-phenylphenoxy) propyl (meth) acrylate, 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate, 2-hydro Aromatic (meth) acrylates such as cis-3- (2-naphthoxy) propyl (meth) acrylate, ethoxylated forms thereof, propoxylated forms thereof, ethoxylated propoxylated forms thereof, and modified caprolactone forms thereof; 2-tetrahydrofurfuryl (meth) acrylate, N- (meth) acryloyloxyethyl tetrahydrophthalimide, N- (meth) acryloyloxyethyl hexahydrophthalimide, isocyanuric acid mono (meth) acrylate, 2- (meth) acryloyloxyethyl- Heterocyclic (meth) acrylates such as N-carbazole, ethoxylated forms thereof, propoxylated forms thereof, ethoxylated propoxylated forms thereof, and caprolactone modified forms thereof.

  Among these, from the viewpoint of transparency and heat resistance, alicyclic (meth) acrylates such as cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and isobornyl (meth) acrylate , These ethoxylated compounds, these propoxylated compounds, these ethoxylated propoxylated compounds, and their caprolactone modified products; benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) Acrylate, o-phenylphenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate , Aromatic (meth) acrylates such as 2-hydroxy-3- (o-phenylphenoxy) propyl (meth) acrylate, ethoxylated forms thereof, propoxylated forms thereof, ethoxylated propoxylated forms thereof, and these Modified products of N- (meth) acryloyloxyethyltetrahydrophthalimide, N- (meth) acryloyloxyethylhexahydrophthalimide, isocyanuric acid mono (meth) acrylate, 2- (meth) acryloyloxyethyl-N-carbazole, etc. A heterocyclic (meth) acrylate such as a heterocyclic (meth) acrylate, an ethoxylated product thereof, a propoxylated product thereof, an ethoxylated propoxylated product thereof, or a modified product of these caprolactones is preferred, and the following general formula ( 4) Aromatic mono (meth) acrylate is more preferred that.

Here, the ethoxylated form, propoxylated form, and ethoxylated propoxylated form of (meth) acrylate are alcohols or phenols [for example, mono (meth) acrylate; CH ₂ = CH (R ²¹ ) -COO] -R ²² (R ²¹ is a hydrogen atom or a methyl group, R ²² is a monovalent organic group) in the case of, instead of the one] represented by HO-R ^22, the alcohol or phenol, respectively, one or more (Meth) acrylate obtained by using, as a raw material, an alcohol having a structure in which ethylene oxide is added, an alcohol having a structure in which one or more propylene oxides are added, or an alcohol having a structure in which one or more ethylene oxides and propylene oxide are added ( for ^{_{example, CH 2 = CH (R 21}} ) -COO- (CH 2 CH 2 O) q -R 22 in the case of ethoxylated body (q is 1 or more Integer, R ^21, R ²² is represented by the same)). For example, an ethoxylated phenoxyethyl (meth) acrylate means a (meth) acrylate obtained by reacting an alcohol obtained by adding ethylene oxide to phenoxyethyl alcohol and acrylic acid or methacrylic acid. The caprolactone-modified product refers to a (meth) acrylate using a modified alcohol obtained by modifying an alcohol used as a raw material for (meth) acrylate with caprolactone (for example, in the case of an ε-caprolactone-modified product of mono (meth) acrylate) ^{_{, CH 2 = CH (R 21}} ) -COO - ((CH 2) 5 COO) q -R 22 (q, R 21, R 22 are the same) represented by)).

In the formula, R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ represents any monovalent group represented by the following formula.

R ⁸ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

Z ¹ is a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ —, and the following formula: Indicates any divalent group shown.

R ⁹ represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. A represents an integer of 2 to 10. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In the general formula (4), Y ¹ represents an oxygen atom, a sulfur _{atom, -OCH 2 -, - SCH 2} -, - O (CH 2 CH 2 O) b -, - O [CH (CH 3) CH 2 O _{] c -, - O [CH} 2 CH (CH 3) O] d -, - O [(CH2) 5 CO 2] e -, and _{-OCH 2 CH (OH) CH 2} O- any divalent And b to e each independently represent an integer of 1 to 10.

  There is no restriction | limiting in particular as bifunctional (meth) acrylate, For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethyleneglycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol Di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, 2-methyl-1,3-propanediol di (meth) acrylate, 2-butyl-2-ethyl- 1,3-propanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1 , -Aliphatic (meth) acrylates such as hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, glycerin di (meth) acrylate, these Ethoxylated compounds, these propoxylated compounds, these ethoxylated propoxylated compounds, and their caprolactone modified products; ethylene glycol type epoxy di (meth) acrylate, diethylene glycol type epoxy di (meth) acrylate, polyethylene glycol type epoxy di (meth) acrylate , Propylene glycol type epoxy di (meth) acrylate, dipropylene glycol type epoxy di (meth) acrylate, polypropylene glycol type epoxy di (meth) acrylate, 1,3-propanedi Type epoxy di (meth) acrylate, 2-methyl-1,3-propanediol type epoxy di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol type epoxy di (meth) acrylate, 1,4 -Butanediol type epoxy di (meth) acrylate, neopentyl glycol type epoxy di (meth) acrylate, 3-methyl-1,5-pentanediol type epoxy di (meth) acrylate, 1,6-hexanediol type epoxy di (meth) acrylate, Aliphatic epoxy (meth) acrylates such as 1,9-nonanediol type epoxy di (meth) acrylate and 1,10-decanediol type epoxy di (meth) acrylate; cyclohexanedimethanol di (meth) acrylate, tricyclodecane dimethanoldi ( Aliphatic (meth) acrylates such as (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate, hydrogenated bisphenol F di (meth) acrylate, ethoxylated compounds thereof, propoxylated compounds thereof, and ethoxylated propoxy compounds thereof And their caprolactone-modified products: cyclohexanedimethanol type epoxy di (meth) acrylate, tricyclodecane dimethanol type epoxy di (meth) acrylate, hydrogenated bisphenol A type epoxy di (meth) acrylate, hydrogenated bisphenol F type epoxy di ( Alicyclic epoxy (meth) acrylates such as meth) acrylate; hydroquinone di (meth) acrylate, resorcinol di (meth) acrylate, catechol di (meth) acrylate, bisphenol A di (meth) acrylate , Aromatic (meth) acrylates such as bisphenol F di (meth) acrylate, bisphenol AF di (meth) acrylate, biphenol di (meth) acrylate, fluorene bisphenol di (meth) acrylate, ethoxylated products thereof, propoxy compounds thereof , Ethoxylated propoxylated products thereof, and modified caprolactone thereof; hydroquinone type epoxy di (meth) acrylate, resorcinol type epoxy di (meth) acrylate, catechol type epoxy di (meth) acrylate, bisphenol A type epoxy di (meth) acrylate , Bisphenol F type epoxy di (meth) acrylate, Bisphenol AF type epoxy di (meth) acrylate, Biphenol type epoxy di (meth) acrylate, Fluorenebi Aromatic epoxy (meth) acrylates such as phenolic epoxy di (meth) acrylates; heterocyclic (meth) acrylates such as isocyanuric acid di (meth) acrylates, ethoxylated products thereof, propoxylated products thereof, ethoxylated products thereof Examples thereof include propoxylated products and modified caprolactones thereof; heterocyclic (meth) acrylates such as isocyanuric acid monoallyl type epoxy di (meth) acrylate and the like.

  Among these, from the viewpoint of transparency and heat resistance, the alicyclic (meth) acrylate, ethoxylated products thereof, propoxylated products thereof, ethoxylated propoxylated products thereof, and modified caprolactone products thereof; Aromatic such as alicyclic epoxy (meth) acrylate; bisphenol A di (meth) acrylate, bisphenol F di (meth) acrylate, bisphenol AF di (meth) acrylate, biphenol di (meth) acrylate, fluorene bisphenol di (meth) acrylate Group (meth) acrylates, ethoxylated products thereof, propoxylated products thereof, ethoxylated propoxylated products thereof, and modified products of caprolactone thereof; bisphenol A type epoxy di (meth) acrylate, bisphenol F type epoxy di (meta) Aromatic epoxy (meth) acrylates such as acrylate, bisphenol AF type epoxy di (meth) acrylate, biphenol type epoxy di (meth) acrylate, fluorene bisphenol type epoxy di (meth) acrylate; the above heterocyclic (meth) acrylates, and ethoxylation thereof , These propoxylated products, these ethoxylated propoxylated products, and their caprolactone modified products; the above-mentioned heterocyclic (meth) acrylates are preferred, and aromatic (meth) acrylates represented by the following general formula (5) An aromatic epoxy (meth) acrylate represented by the following general formula (6) is more preferable. The ethoxylated product, propoxylated product, ethoxylated propoxylated product, and caprolactone-modified product have the same meaning as described above.

In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, and may be the same or different. R ¹¹ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In the formula, Z ² represents a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ —, and One of the divalent groups represented by the formula is shown.

R ¹² represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. F represents an integer of 2 to 10. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In the general formula (5), Y ² represents an oxygen atom, a sulfur _{atom, -OCH 2 -, - SCH 2} -, - O (CH 2 CH 2 O) g -, - O [CH (CH 3) CH 2 O] _h- , —O [CH ₂ CH (CH ₃ ) O] _i —, and —O [(CH ₂ ) ₅ CO ₂ ] _j — are included and may be the same or different. G to j each independently represent an integer of 1 to 10.

  In the formula, k represents an integer of 1 to 10.

In the formula, R ¹³ represents a hydrogen atom or a methyl group, and may be the same or different. R ¹⁴ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In the formula, Z ² represents a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ —, and One of the divalent groups represented by the formula is shown.

R ¹⁵ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. L represents an integer of 2 to 10. As the monovalent organic group having 1 to 20 carbon atoms, mention may be made of suitably the same as those described as specific examples of R ¹ described above.

In General Formula (6), Y ³ represents an oxygen atom, a sulfur atom, —O (CH ₂ CH ₂ O) _m —, —O [CH (CH ₃ ) CH ₂ O] _n —, —O [CH ₂ CH ( The divalent group includes any one of CH ₃ ) O] _o — and —O [(CH ₂ ) ₅ CO ₂ ] _p —, which may be the same or different. M to p each independently represents an integer of 1 to 10.

Examples of tri- or higher functional (meth) acrylates include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta ( Aliphatic (meth) acrylates such as (meth) acrylate and dipentaerythritol hexa (meth) acrylate, ethoxylated products thereof, propoxylated products thereof, ethoxylated propoxylated products thereof, and caprolactone modified products thereof; phenol novolac Type epoxy (meth) acrylate, aromatic epoxy (meth) acrylate such as cresol novolac type epoxy poly (meth) acrylate; isocyanuric acid tri (meth) acrylate Heterocyclic (meth) acrylates such as carbonates, these ethoxylated compounds, these propoxylated compounds, these ethoxylated propoxylated compounds, and these caprolactone modified compounds; complex such as isocyanuric acid type epoxy (meth) acrylates Examples thereof include cyclic (meth) epoxy acrylate. The ethoxylated product, propoxylated product, ethoxylated propoxylated product, and caprolactone-modified product have the same meaning as described above.
Among these, from the viewpoint of transparency and heat resistance, the aromatic epoxy (meth) acrylate; the heterocyclic (meth) acrylate; and the isocyanuric acid type epoxy (meth) acrylate are preferable.
The above (meth) acrylates can be used alone or in combination of two or more, and can also be used in combination with other polymerizable compounds.

  It is preferable that the compounding quantity of the said (B) component is 10-60 mass% with respect to the total amount of (A)-(C) component. When it is 10% by mass or more, the component (A) is sufficiently entangled and cured at the time of photocuring, so that the developer resistance is good, and when it is 60% by mass or less, the solubility in an alkali developer is high. It is good. From the above viewpoint, the blending amount of the component (B) is more preferably 15 to 55% by mass, and particularly preferably 20 to 50% by mass.

((C) Compound having two or more epoxy groups in the molecule and having an epoxy equivalent of 250 to 1000 g / eq)
In the present invention, (C) a compound having two or more epoxy groups in the molecule and having an epoxy equivalent of 250 to 1000 g / eq is used. When a compound having two or more epoxy groups in the molecule is used, a new cross-linked structure is formed by reacting the epoxy group with the carboxyl group of the component (A) by heating after forming a core pattern by exposure and development. It can be formed and heat resistance can be improved, and after the reflow test, an increase in light propagation loss after heat treatment under conditions of 180 ° C. and 1 hour can be suppressed.

  The reaction between the epoxy group and the carboxyl group proceeds even at room temperature without heating. If the reaction proceeds before the core pattern is formed by exposure and development, a crosslinked structure is formed and becomes insoluble in the developer. Therefore, it is necessary to suppress the reaction during storage. When the epoxy equivalent of the component (C) is 250 g / eq or more, the heat resistance can be improved, and an optical waveguide forming resin composition and an optical waveguide forming resin film described later comprising the resin composition can be used. The reaction between the epoxy group and the carboxyl group that can occur during storage can be suppressed, and the storage stability can be improved. On the other hand, when the epoxy equivalent is 1000 g / eq or less, a crosslinked structure can be sufficiently formed, heat resistance can be improved, and solubility in an alkali developer is good. From the above viewpoint, the epoxy equivalent of the component (C) is more preferably 260 to 750, and particularly preferably 270 to 500.

(C) There is no restriction | limiting in particular as a compound which has two or more epoxy groups in a molecule | numerator, and an epoxy equivalent is 250-1000 g / eq, For example, a polyethylene glycol type epoxy resin, a polypropylene specifically, Polyfunctional aliphatic alcohol glycidyl ether such as glycol type epoxy resin; hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated 2,2′-biphenol type epoxy resin, hydrogenated 4,4′-biphenol Type epoxy resin, polyfunctional alicyclic alcohol glycidyl ether such as tricyclodecane dimethanol type epoxy resin; bisphenol A type epoxy resin, tetrabromobisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, bisphenol D type epoxy resin, fluorene bisphenol type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, cresol aralkyl type epoxy resin, dicyclopentadiene-phenol Polyfunctional phenol glycidyl ethers such as epoxy resins; polyfunctional heterocyclic epoxy resins such as ethoxylated isocyanurate type epoxy resins; polyfunctional silicon-containing epoxy resins such as siloxane type epoxy resins.
Among these, from the viewpoint of transparency and heat resistance, a compound containing in the molecule at least one of an alicyclic structure, an aromatic ring structure, and a heterocyclic structure is preferable, and specifically, the polyfunctional alicyclic alcohol. Preferred is glycidyl ether; the polyfunctional phenol glycidyl ether; and the polyfunctional heterocyclic epoxy resin.

Commercially available epoxy resins such as “Epicoat YX8034” (epoxy equivalent 290 g / eq), “Epicoat YL7170” (epoxy equivalent 1000 g / eq) manufactured by Japan Epoxy Resin Co., Ltd., Toto Kasei Co., Ltd. Hydrogenated bisphenol A type epoxy resin such as “Epototo ST-4000D” (epoxy equivalent 700 g / eq) manufactured by Japan; “Epicoat 834” (epoxy equivalent 250 g / eq), “Epicoat 1001” (epoxy equivalent) manufactured by Japan Epoxy Resin Co., Ltd. 475 g / eq), “Epicoat 1002” (epoxy equivalent 650 g / eq), “Epicoat 1003” (epoxy equivalent 720 g / eq), “Epicoat 1003F” (epoxy equivalent 750 g / eq), “Epicoat 1004FS” (epoxy equivalent 810) / Eq), "Epicoat 1055" (epoxy equivalent 850 g / eq), "Epicoat 1004" (epoxy equivalent 925 g / eq), "Epicoat 1004AF" (epoxy equivalent 925 g / eq), "Epicoat 1004F" (epoxy equivalent 925 g / eq) ), “Epicoat 1005F” (epoxy equivalent 1000 g / eq), “Epicoat 1006FS” (epoxy equivalent 1000 g / eq), “Epototo YD-134” (epoxy equivalent 250 g / eq) manufactured by Tohto Kasei Co., Ltd., “Epototo YD- "011" (epoxy equivalent 475 g / eq), "epototo YD-7011R" (epoxy equivalent 475 g / eq), "epototo YD-901" (epoxy equivalent 475 g / eq), "epototo YD-012" (epoxy equivalent 650 g / eq) ), "D Tote YD-902 "(epoxy equivalent 650 g / eq)," epototo YD-903N "(epoxy equivalent 810 g / eq)," epototo YD-013 "(epoxy equivalent 850 g / eq)," epototo YD-014 "(epoxy equivalent) 950g / eq), "Epototo YD-904" (epoxy equivalent 950g / eq) and other bisphenol A type epoxy resins; Shin Nippon Rika Co., Ltd. "Likaresin BEO-60E" (epoxy equivalent 365g / eq) Bisphenol A type epoxy resin: “Epicoat 4004P” (epoxy equivalent 880 g / eq) manufactured by Japan Epoxy Resin Co., Ltd. “Epototo YDF-2001” (epoxy equivalent 475 g / eq) manufactured by Toto Kasei Co., Ltd. “Epototo YDF-2004” (Epoxy equivalent 950 g / e bisphenol F type epoxy resin such as q); “Epototo YDB-360” (epoxy equivalent 360 g / eq), “Epototo YDB-400” (epoxy equivalent 400 g / eq), “Epototo YDB-405” manufactured by Tohto Kasei Co., Ltd. Tetrabromobisphenol A type epoxy resin such as (epoxy equivalent 580 g / eq); Biphenyl type epoxy resin such as “Epiclon EXA-7400” (epoxy equivalent 290 g / eq) manufactured by DIC Corporation; “manufactured by Nagase ChemteX Corporation” "ONCOAT EX-1060" (epoxy equivalent 265 g / eq), "ONCOAT EX-1012" (epoxy equivalent 292 g / eq), "ONCOAT EX-1020" (epoxy equivalent 305 g / eq), "ONCOAT EX-1050 (Epoxy equivalent 312 g / eq), “onco Fluorene bisphenol type epoxy resin such as “EXEX1051” (epoxy equivalent 315 g / eq); “BREN-105” (epoxy equivalent 275 g / eq), “BREN-S” (epoxy equivalent 285 g / eq), “BREN-304” (epoxy equivalent 310 g / eq) and other bromophenol novolac type epoxy resins; Nippon Kayaku Co., Ltd. “NC-3000” (epoxy equivalent 275 g / eq), “NC-3000-H” "Epoxylon HP-7200" (epoxy equivalent 260 g / eq), "Epiclon HP-7200H" (epoxy equivalent 280 g / eq), etc. manufactured by DIC Corporation Dicyclopentadiene-phenol type epoxy resin; Nagase Such Mutekkusu Ltd. "Denacol EX-301" (epoxy equivalent 270 g / eq) ethoxylated isocyanurate type epoxy resins, and the like.
In addition, the epoxy equivalent value described here is a value reported in the catalog.

  The blending amount of the component (C) is preferably 1 to 40% by mass with respect to the total amount of the components (A) to (C). When the content is 1% by mass or more, a sufficient cross-linked structure is formed with the component (A), so that the heat resistance is good, and when it is 40% by mass or less, the solubility in an alkali developer is good. From the above viewpoint, the amount of component (C) is more preferably 3 to 35% by mass, and particularly preferably 5 to 30% by mass.

((D) radical polymerization initiator)
(D) 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 rays. For example, a thermal radical polymerization initiator or a photo radical polymerization initiator. Etc.

There is no restriction | limiting in particular as a thermal radical polymerization initiator, The thing similar to the thermal radical polymerization initiator used when synthesize | combining the said (meth) acrylic polymer can be mentioned suitably.
Among them, diacyl peroxide, peroxyester, and azo compound are preferable from the viewpoints of curability, transparency, and heat resistance.

The radical photopolymerization initiator is not particularly limited as long as it initiates radical polymerization by irradiation with actinic rays such as ultraviolet rays and visible rays. For example, 2,2-dimethoxy-1,2-diphenylethane-1- Benzoinketals such as ON; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2- Α-hydroxy ketones such as methyl-1-propan-1-one, 2-hydroxy-1- {4 [4- (2-hydroxy-2-methylpropionyl) benzyl] phenyl} -2-methylpropan-1-one Methyl phenylglyoxylate, ethyl phenylglyoxylate, 2- (2-hydroxyoxyphenylacetic acid) Glyoxyesters such as 2- (2-oxo-2-phenylacetoxyethoxy) ethyl; 2-benzyl-2-dimethylamino-1- (4-morpholin-4-ylphenyl)- Butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-ylphenyl) -butan-1-one, 1,2-methyl-1- [4 Α-amino ketones such as-(methylthio) phenyl]-(4-morpholin) -2-ylpropan-1-one; 1,2-octanedione, 1- [4- (phenylthio), 2- (O-benzoyl) Oxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl], 1- (O-acetyloxime) Ter; bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluoro) Phenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer 2,4,5-triarylimidazole dimers such as benzophenone, N, Benzophenone compounds such as'-tetramethyl-4,4'-diaminobenzophenone, N, N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone; 2-ethylanthraquinone, phenanthrenequinone 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1, Quinone compounds such as 4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone; benzoin methyl ether, benzoin ethyl ether, benzoin Benzoin ethers such as benzyl ether; benzoin compounds such as benzoin, methyl benzoin, ethyl benzoin; benzyl compounds such as benzyl dimethyl ketal; acridines such as 9-phenylacridine, 1,7-bis (9,9′-acridinylheptane) Compound: N-phenylglycine, coumarin and the like can be mentioned.
In the 2,4,5-triarylimidazole dimer, the substituents of the aryl groups at the two triarylimidazole sites may give the same and symmetric compounds, but give differently asymmetric compounds. May be.
Among these, from the viewpoint of curability and transparency, the α-hydroxyketone; the glyoxyester; the oxime ester; and the phosphine oxide are preferable.
The above radical polymerization initiators (such as a thermal radical polymerization initiator and a photo radical polymerization initiator) can be used alone or in combination of two or more, and can also be used in combination with an appropriate sensitizer.

  The blending amount of the component (D) is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) to (C). When it is 0.01 parts by mass or more, curing is sufficient, and when it is 10 parts by mass or less, transparency is good. From the above viewpoint, the amount of component (D) is more preferably 0.05 to 7 parts by mass, and particularly preferably 0.1 to 5 parts by mass.

((E) Curing accelerator)
If necessary, the resin composition for forming an optical waveguide of the present invention may further contain (E) a curing accelerator in a proportion that does not adversely affect the effects of the present invention.
(E) The curing accelerator is not particularly limited as long as it is a compound that accelerates the reaction between the carboxyl group of the component (A) and the epoxy group of the component (C). For example, tri-n-butylamine, benzyl Secondary amines such as methylamine and methylaniline; triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, diethylisopropylamine, benzyldimethylamine, N, N-dimethylaniline, N, N, N Tertiary amines such as', N'-tetramethylethylenediamine; pyrrolidine, N-methylpyrrolidine, piperidine, N-methylpiperidine, morpholine, N-methylmorpholine, piperazine, N, N'-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] Octane, 1,5-diazabicyclo [4 3.0] cyclic amines such as non-5-ene and 1,8-diazabicyclo [5.4.0] undec-7-ene; 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2- Heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-1-methylimidazole, 1,2-diethylimidazole, 1-ethyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethylimidazole, 1-cyanoethyl-2 -Phenylimidazole, 1-cyanoethyl-2-ethyl -4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')] ethyl- Imidazole compounds such as s-triazine and 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)] ethyl-s-triazine; trimellitic acid adducts of the imidazole compounds; Isocyanuric acid adducts of compounds; hydrobromic acid adducts of the above imidazole compounds; tetra-n-butylammonium chloride, teto bromide -n- butylammonium iodide tetra -n- butylammonium, benzyltrimethylammonium chloride, bromide benzyltrimethylammonium, and the like quaternary ammonium salts, such as benzyl iodide trimethylammonium.
Among these, from the viewpoint of transparency and curability, the imidazole compound; the trimellitic acid adduct of the imidazole compound; and the isocyanuric acid adduct of the imidazole compound are preferable.
These compounds can be used alone or in combination of two or more.

  It is preferable that the compounding quantity of the said (E) component is 0.01-10 mass parts with respect to 100 mass parts of total amounts of (A)-(C) component. When it is 0.01 parts by mass or more, the (A) component and the (C) component form a sufficient crosslinked structure, so that the heat resistance is good, and when it is 10 parts by mass or less, the (A) component and ( The reaction of component C) can be suppressed, and the storage stability can be improved. From the above viewpoint, the amount of component (E) is more preferably 0.05 to 7 parts by mass, and particularly preferably 0.1 to 5 parts by mass.

(Other ingredients)
Furthermore, in the resin composition for forming an optical waveguide of the present invention, an antioxidant, an anti-yellowing agent, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, a stabilizer, a filler, etc., as necessary. These so-called additives may be added at a rate that does not adversely affect the effects of the present invention.

(Organic solvent)
The resin composition for forming an optical waveguide of the present invention may be diluted with a suitable organic solvent and used as a resin varnish for forming an optical waveguide. The organic solvent used here is not particularly limited as long as it can dissolve the resin composition, and the organic solvent used as a reaction solvent capable of dissolving the (meth) acrylic polymer can be preferably exemplified. it can.
These organic solvents can be used alone or in combination of two or more. Moreover, it is preferable that the solid content density | concentration in a resin varnish is 10-80 mass% normally.

(Preparation of resin composition for optical waveguide formation)
When the resin composition for forming an optical waveguide is prepared, it is preferably mixed by stirring. Although there is no restriction | limiting in particular in the stirring method, From the viewpoint of stirring efficiency, stirring using a propeller is preferable. Although there is no restriction | limiting in particular in the rotational speed of the propeller at the time of stirring, It is preferable that it is 10-1,000 rpm. When it is 10 rpm or more, each component is sufficiently mixed, and when it is 1,000 rpm or less, entrainment of bubbles due to rotation of the propeller is reduced. From the above viewpoint, the rotation speed of the propeller is more preferably 50 to 800 rpm, and particularly preferably 100 to 500 rpm.
The stirring time is not particularly limited, but is preferably 1 to 24 hours. When the stirring time is 1 hour or more, the respective components are sufficiently mixed, and when it is 24 hours or less, the preparation time can be shortened, and the productivity is improved.

  The prepared resin composition for forming an optical waveguide is preferably filtered using a filter having a pore diameter of 50 μm or less. By using a filter having a pore diameter of 50 μm or less, large foreign matters are not removed, and repellency is not caused at the time of application, and light scattering is suppressed and transparency is not impaired. From the above viewpoint, it is more preferable to filter using a filter having a pore diameter of 30 μm or less, and it is particularly preferable to filter using a filter having a pore diameter of 10 μm or less.

  The prepared optical waveguide forming resin composition or resin varnish is preferably degassed under reduced pressure. Although there is no restriction | limiting in particular in the defoaming method, For example, the method of using a vacuum pump, a bell jar, and the defoaming apparatus with a vacuum apparatus is mentioned. Although there is no restriction | limiting in particular in the pressure at the time of pressure reduction, The pressure in which the low boiling point component contained in a resin composition does not boil is preferable. Although there is no restriction | limiting in particular in vacuum degassing time, It is preferable that it is 3 to 60 minutes. If it is 3 minutes or longer, bubbles dissolved in the resin composition can be removed, and if it is 60 minutes or less, the organic solvent contained in the resin composition does not volatilize and the defoaming time is shortened. And productivity can be improved.

(Resin film for optical waveguide formation)
The resin film for forming an optical waveguide of the present invention uses the resin composition for forming an optical waveguide, and includes the components (A) to (D) and, further, the component (E) used as necessary. It can manufacture easily by apply | coating the resin composition for a suitable support film. Moreover, when the resin composition for forming an optical waveguide is a resin varnish for forming an optical waveguide diluted with the organic solvent, it can be produced by applying the resin varnish to a support film and removing the organic solvent.

The support film is not particularly limited. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polycarbonates, polyamides, polyimides, polyamideimides, polyetherimides, polyether sulfides, Examples include polyethersulfone, polyetherketone, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, and liquid crystal polymer.
Among these, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, polyarylate, and polysulfone are preferable from the viewpoints of flexibility and toughness.
In addition, from the viewpoint of improving releasability from the resin layer, a film that has been subjected to release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  The thickness of the support film may be appropriately changed depending on the intended flexibility, but is preferably 3 to 250 μm. When it is 3 μm or more, the film strength is sufficient, and when it is 250 μm or less, sufficient flexibility is obtained. From the above viewpoint, the thickness of the support film is more preferably 5 to 200 μm, and particularly preferably 7 to 150 μm.

  An optical waveguide forming resin film manufactured by applying an optical waveguide forming resin composition on a support film is composed of a support film, a resin layer, and a protective film, with a protective film attached to the resin layer as necessary. A three-layer structure may be used.

  The protective film is not particularly limited, but from the viewpoint of flexibility and toughness, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene are preferable. In addition, you may use the film in which the mold release process was given with the silicone type compound, the fluorine-containing compound, etc. from a viewpoint of peelability improvement with a resin layer as needed.

  The thickness of the protective film may be appropriately changed depending on the intended flexibility, but is preferably 10 to 250 μm. When it is 10 μm or more, the film strength is sufficient, and when it is 250 μm or less, sufficient flexibility is obtained. From the above viewpoint, the thickness of the protective film is more preferably 15 to 200 μm, and particularly preferably 20 to 150 μm.

  The thickness of the resin layer of the resin film for forming an optical waveguide of the present invention is not particularly limited, but it is preferably 5 to 500 μm as a thickness after drying. If the thickness is 5 μm or more, the strength of the resin film or the cured product of the resin film is sufficient because the thickness is sufficient. On the other hand, if the thickness is 500 μm or less, the drying can be performed sufficiently and the amount of residual solvent in the resin film increases. Without foaming when the cured product of the resin film is heated.

  The resin film for forming an optical waveguide thus obtained can be easily stored, for example, by winding it into a roll. Moreover, a roll-shaped film can be cut out into a suitable size and stored in a sheet shape.

Hereinafter, application examples of the resin film for forming an optical waveguide of the present invention will be described.
The support film used in the process of manufacturing the core portion forming resin film is not particularly limited as long as it can transmit the actinic ray for exposure used for forming the core pattern. The thing similar to what was described as a specific example of a support film can be mentioned suitably.
Among these, polyesters and polyolefins are preferable from the viewpoints of the transmittance of actinic rays for exposure, flexibility, and toughness. Furthermore, it is more preferable to use a highly transparent support film from the viewpoint of improving the transmittance of exposure actinic rays and reducing the side wall roughness of the core pattern. Examples of such a highly transparent support film include commercially available “Cosmo Shine A1517”, “Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., “Lumirror FB50” manufactured by Toray Industries, Inc., and the like.
In addition, from the viewpoint of improving releasability from the resin layer, a film that has been subjected to release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  The thickness of the support film of the core portion forming resin film is preferably 5 to 50 μm. When it is 5 μm or more, the strength as a support is sufficient, and when it is 50 μm or less, the gap between the photomask and the core portion forming resin layer is not increased when the core pattern is formed, and the pattern resolution is good. From the above viewpoint, the thickness of the support film is more preferably 10 to 40 μm, and particularly preferably 15 to 30 μm.

(Optical waveguide)
Hereinafter, the optical waveguide of the present invention will be described.
A sectional view of the optical waveguide is shown in FIG. The optical waveguide 1 is formed on a base material 5 and includes a core part 2 made of a core part-forming resin composition having a high refractive index, a lower clad layer 4 made of a clad layer-forming resin composition having a low refractive index, and The upper clad layer 3 is used.
The resin composition for forming an optical waveguide and the resin film for forming an optical waveguide of the present invention are preferably used for at least one of the lower cladding layer 4, the core portion 2, and the upper cladding layer 3 of the optical waveguide 1.

  By using the optical waveguide forming resin film, the flatness of each layer, the interlayer adhesion between the clad and the core, and the resolution (correspondence between thin lines or narrow lines) at the time of forming the optical waveguide core pattern can be further improved. It is excellent in flatness, and it is possible to form a fine pattern with a small line width and line spacing.

  In the optical waveguide 1, the material of the base material 5 is not particularly limited. For example, a glass epoxy resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a plastic substrate, a metal substrate, a substrate with a resin layer, a substrate with a metal layer, Examples thereof include a plastic film, a plastic film with a resin layer, and a plastic film with a metal layer.

The optical waveguide 1 may be a flexible optical waveguide by using a base material having flexibility and toughness as the base material 5, for example, a support film of the resin film for forming an optical waveguide as a base material. 5 may function as a protective film for the optical waveguide 1. By disposing the protective film, the flexibility and toughness of the protective film can be imparted to the optical waveguide 1. Furthermore, since the optical waveguide 1 is not damaged or scratched, the ease of handling is improved.
From the above viewpoint, the base material 5 is disposed as a protective film outside the upper clad layer 3 as shown in FIG. 1B, or the lower clad layer 4 and the upper clad layer as shown in FIG. The base material 5 may be arrange | positioned as a protective film on both the outer sides of 3.
If the optical waveguide 1 has sufficient flexibility and toughness, the protective film 5 may not be disposed as shown in FIG.

The thickness of the lower clad layer 4 is not particularly limited, but is preferably 2 to 200 μm. If it is 2 μm or more, it becomes easy to confine the propagating light inside the core, and if it is 200 μm or less, the entire thickness of the optical waveguide 1 is not too large. The thickness of the lower cladding layer 4 is a value from the boundary between the core portion 2 and the lower cladding layer 4 to the lower surface of the lower cladding layer 4.
There is no restriction | limiting in particular about the thickness of the resin film for lower clad layer formation, and thickness is adjusted so that the thickness of the lower clad layer 4 after hardening may become said range.

  The height of the core part 2 is not particularly limited, but is preferably 10 to 150 μm. When the height of the core is 10 μm or more, the alignment tolerance is not reduced in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed, and when the core portion is 150 μm or less, the light is received and emitted after the optical waveguide is formed. In coupling with an element or an optical fiber, coupling efficiency is not reduced. From the above viewpoint, the height of the core part is more preferably 15 to 130 μm, and particularly preferably 20 to 120 μm. In addition, there is no restriction | limiting in particular about the thickness of the resin film for core part formation, Thickness is adjusted so that the height of the core part after hardening may become said range.

  The thickness of the upper cladding layer 3 is not particularly limited as long as the core portion 2 can be embedded, but the thickness after drying is preferably 12 to 500 μm. The thickness of the upper clad layer 3 may be the same as or different from the thickness of the lower clad layer 4 formed first, but is thicker than the thickness of the lower clad layer 4 from the viewpoint of embedding the core portion 2. It is preferable. The thickness of the upper cladding layer 3 is a value from the boundary between the core portion 2 and the lower cladding layer 4 to the upper surface of the upper cladding layer 3.

  In the optical waveguide of the present invention, the light propagation loss is preferably 0.3 dB / cm or less. When it is 0.3 dB / cm or less, the loss of light becomes small and the strength of the transmission signal is sufficient. From the above viewpoint, the light propagation loss is more preferably 0.2 dB / cm or less, and particularly preferably 0.1 dB / cm or less.

In the optical waveguide of the present invention, the light propagation loss after a high temperature and high humidity leaving test at a temperature of 85 ° C. and a humidity of 85% for 1000 hours is preferably 0.3 dB / cm or less. When it is 0.3 dB / cm or less, the loss of light becomes small and the strength of the transmission signal is sufficient. From the above viewpoint, the light propagation loss is more preferably 0.2 dB / cm or less, and particularly preferably 0.1 dB / cm or less.
The high-temperature and high-humidity storage test at a temperature of 85 ° C. and a humidity of 85% means a high-temperature and high-humidity storage test performed under conditions in accordance with the JPCA standard (JPCA-PE02-05-01S).

In the optical waveguide of the present invention, the light propagation loss after 1000 cycles of the temperature cycle test between −55 ° C. and 125 ° C. is preferably 0.3 dB / cm or less. When it is 0.3 dB / cm or less, the loss of light becomes small and the strength of the transmission signal is sufficient. From the above viewpoint, the light propagation loss is more preferably 0.2 dB / cm or less, and particularly preferably 0.1 dB / cm or less.
In addition, the temperature cycle test between temperature -55 degreeC and 125 degreeC means the temperature cycle test implemented on the conditions according to a JPCA standard (JPCA-PE02-05-01S).

In the optical waveguide of the present invention, it is preferable that the light propagation loss after performing the reflow test at the maximum temperature of 265 ° C. three times is 0.3 dB / cm or less. If it is 0.3 dB / cm or less, the loss of light becomes small, and if the intensity of the transmission signal is sufficient, component mounting by the reflow process can be performed at the same time, so the applicable range is widened. From the above viewpoint, the light propagation loss is more preferably 0.2 dB / cm or less, and particularly preferably 0.1 dB / cm or less.
The reflow test at the maximum temperature of 265 ° C. means a lead-free solder reflow test that is performed under conditions in accordance with the JEDEC standard (JEDEC JESD22A113E).

  In the optical waveguide of the present invention, the light propagation loss after heat treatment under the conditions of 180 ° C. and 1 hour is preferably 0.3 dB / cm or less. When it is 0.3 dB / cm or less, the electric wiring board and the optical waveguide can be bonded together under the above-described conditions in the manufacturing process of the opto-electric composite flexible wiring board. From the above viewpoint, the light propagation loss is more preferably 0.2 dB / cm or less, and particularly preferably 0.1 dB / cm or less.

The optical waveguide of the present invention is excellent in transparency, reliability, and heat resistance, and may be used as an optical transmission path of an optical module. Examples of the optical module include an optical waveguide with an optical fiber in which optical fibers are connected to both ends of the optical waveguide, an optical waveguide with a connector in which connectors are connected to both ends of the optical waveguide, and an optoelectric device in which the optical waveguide and the printed wiring board are combined. Examples include a composite substrate, an optical / electrical conversion module that combines an optical waveguide and an optical / electrical conversion element that mutually converts an optical signal and an electrical signal, and a wavelength multiplexer / demultiplexer that combines an optical waveguide and a wavelength division filter.
In the photoelectric composite substrate, the printed wiring board to be combined is not particularly limited, and examples thereof include rigid substrates such as glass epoxy substrates and ceramic substrates; flexible substrates such as polyimide substrates and polyethylene terephthalate substrates.

(Optical waveguide manufacturing method)
Hereinafter, the manufacturing method for forming the optical waveguide 1 using the resin composition for forming an optical waveguide and / or the resin film for forming an optical waveguide of the present invention will be described.
There is no restriction | limiting in particular as a method to manufacture the optical waveguide 1 of this invention, For example, the resin layer for optical waveguide formation on a base material using the resin composition for optical waveguide formation and / or the resin film for optical waveguide formation is used. And the like, and the like.

  The base material used in the present invention is not particularly limited, and is a glass epoxy resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a plastic substrate, a metal substrate, a substrate with a resin layer, a substrate with a metal layer, a plastic film, a resin layer. And a plastic film with a metal layer and a plastic film with a metal layer.

The method for forming the optical waveguide forming resin layer is not particularly limited, for example, using the optical waveguide forming resin composition, spin coating method, dip coating method, spray method, bar coating method, roll coating method, Examples of the coating method include a curtain coating method, a gravure coating method, a screen coating method, and an inkjet coating method.
When the resin composition for forming an optical waveguide is diluted with the organic solvent to form a resin varnish for forming an optical waveguide, a drying step may be added after forming the resin layer as necessary. There is no restriction | limiting in particular as a drying method, For example, heat drying, reduced pressure drying, etc. are mentioned. Moreover, you may use these together as needed.

As another method of forming the optical waveguide forming resin layer, a method of forming the optical waveguide forming resin film using the optical waveguide forming resin composition by a laminating method may be mentioned.
Among these, from the viewpoint that an optical waveguide having excellent flatness and having a fine pattern with a small line width and a small line pattern can be formed, a method of producing by a lamination method using a resin film for forming an optical waveguide is preferable.

Hereinafter, although the manufacturing method for forming the optical waveguide 1 using the resin film for optical waveguide formation for a lower clad layer, a core part, and an upper clad layer is demonstrated, this invention is not restrict | limited at all to this. .
First, as a first step, a resin film for forming a lower clad layer is laminated on the substrate 5. There is no restriction | limiting in particular as a lamination | stacking method in a 1st process, For example, the method of laminating | stacking by crimping, heating using a roll laminator or a flat plate laminator etc. is mentioned. The flat plate laminator in the present invention refers to a laminator in which a laminated material is sandwiched between a pair of flat plates and pressed by pressing the flat plate. For example, a vacuum pressurizing laminator can be suitably used. The laminating temperature is not particularly limited, but is preferably 20 to 130 ° C., and the laminating pressure is not particularly limited, but is preferably 0.1 to 1.0 MPa. When a protective film exists in the resin film for lower clad layer formation, it laminates | stacks, after removing a protective film.

  When laminating using a vacuum pressurizing laminator, a lower clad layer forming resin film may be temporarily pasted onto the substrate 5 in advance using a roll laminator. Here, from the viewpoint of improving adhesion and followability, it is preferable to perform temporary bonding while pressure bonding. When pressure bonding, it may be performed while heating using a laminator having a heat roll. The laminating temperature is preferably 20 to 150 ° C. If it is 20 degreeC or more, the adhesiveness of the resin film for lower clad layer formation and the base material 5 will improve, and if it is 150 degrees C or less, the resin layer does not flow too much at the time of roll lamination, and the required film thickness is can get. From the above viewpoint, the temperature is more preferably 40 to 130 ° C. The laminating pressure is not particularly limited, but is preferably 0.2 to 0.9 MPa, and the laminating speed is not particularly limited, but is preferably 0.1 to 3 m / min.

The lower clad layer forming resin layer laminated on the substrate 5 is cured by light and / or heat to form the lower clad layer 4. The removal of the support film of the lower clad layer forming resin film may be performed either before or after curing.
Although there is no restriction | limiting in particular in the irradiation amount of the actinic light at the time of hardening | curing the resin layer for lower clad layer formation with light, It is preferable to set it as 0.1-5 J / cm < ² >. Moreover, when actinic light permeate | transmits a base material, in order to harden | cure efficiently, the double-sided exposure machine which can irradiate actinic light simultaneously from both surfaces can be used. Moreover, you may irradiate actinic light, heating. In addition, as a process before and behind photocuring, you may perform a 50-200 degreeC heat processing as needed.
The heating temperature for curing the resin layer for forming the lower cladding layer with heat is not particularly limited, but is preferably 50 to 200 ° C.

When the support film for the resin film for forming the lower clad layer functions as the protective film 5 for the optical waveguide 1, it is cured under the same conditions as described above by light and / or heat without laminating the resin film for forming the lower clad layer. Then, the lower cladding layer 4 may be formed.
In addition, the protective film of the resin film for lower clad layer formation may be removed before hardening, or may be removed after hardening.

  As the second step, a core part-forming resin film is laminated on the lower cladding layer 4 by the same method as in the first step. Here, the resin layer for forming the core part is designed to have a higher refractive index than the resin layer for forming the lower clad layer, and is made of a photosensitive resin composition capable of forming the core part 2 (core pattern) by actinic rays. Is preferred.

As a third step, the core portion 2 is exposed. The method for exposing the core part 2 is not particularly limited. For example, a method of irradiating an actinic ray in an image form through a negative photomask called artwork, without passing through a negative photomask using direct laser drawing. For example, a method of directly irradiating an active ray on an image can be mentioned.
The light source of the actinic ray is not particularly limited, and for example, a light source that effectively emits ultraviolet rays such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a mercury vapor arc lamp, a metal halide lamp, a xenon lamp, and a carbon arc lamp; A light source that effectively emits visible light, such as a light bulb and a solar lamp.

It is preferable that the irradiation amount of the actinic ray at the time of exposing the core part 2 is 0.01-10 J / cm < ² >. When it is 0.01 J / cm ² or more, the curing reaction proceeds sufficiently and the core portion 2 is not washed away by development. On the other hand, if it is 10 J / cm ² or less, the core portion 2 does not become thick due to excessive exposure, and a fine pattern can be formed. From these viewpoints, the dose of active ray is more preferably from 0.03~5J / cm ^2, and particularly preferably 0.05~3J / cm ^2.
The core part 2 may be exposed through the support film of the core part forming resin film or after the support film is removed.

  Moreover, you may perform post-exposure heating as needed from a viewpoint of the resolution of the core part 2 and adhesive improvement after exposure. The time from ultraviolet irradiation to post-exposure heating is preferably within 10 minutes, but this condition is not particularly limited. The post-exposure heating temperature is preferably 40 to 160 ° C., and the time is preferably 30 seconds to 10 minutes, but these conditions are not particularly limited.

As a 4th process, when exposed through the support film of the resin film for core part formation, this is removed and it develops using an alkali developing solution.
The development method is not particularly limited, and examples thereof include a spray method, a dip method, a paddle method, a spin method, a brushing method, and a scraping method. Moreover, you may use these image development methods together as needed.
There is no restriction | limiting in particular as an alkali developing solution, For example, the aqueous | water-based alkaline developing solution which consists of alkaline aqueous solution; The semi-aqueous alkaline developing solution which consists of alkaline aqueous solution and 1 or more types of organic solvent etc. are mentioned.
The development temperature is adjusted in accordance with the developability of the core portion forming resin layer.

There is no restriction | limiting in particular as a base of aqueous alkali solution, For example, Alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide; Alkali metal carbonates, such as lithium carbonate, sodium carbonate, potassium carbonate; Hydrogen carbonate Alkali metal bicarbonates such as lithium, sodium bicarbonate and potassium bicarbonate; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; tetraboric acid Sodium salts such as sodium and sodium metasilicate; ammonium salts such as ammonium carbonate and ammonium hydrogen carbonate; tetramethylammonium hydroxide, triethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3 Propanediol, organic bases such as 1,3-diamino-propanol-2-morpholine.
These bases can be used alone or in combination of two or more.
The pH of the aqueous alkaline developer is preferably 9-14. Further, a surfactant, an antifoaming agent or the like may be mixed in the aqueous alkaline developer.

The quasi-aqueous alkaline developer is not particularly limited as long as it comprises an aqueous alkali solution and one or more organic solvents. In addition, there is no restriction | limiting in particular as an organic solvent, For example, the thing similar to the organic solvent used for dilution of the above-mentioned resin composition for optical waveguide formation can be mentioned suitably.
The pH of the quasi-aqueous alkaline developer is preferably as low as possible within a range where development can be sufficiently performed, preferably pH 8 to 13, and more preferably pH 9 to 12.
The concentration of the organic solvent is usually preferably 2 to 90% by mass. Further, a small amount of a surfactant, an antifoaming agent or the like may be mixed in the semi-aqueous alkaline developer.

As a treatment after development, the organic solvent, a semi-aqueous cleaning solution composed of the organic solvent and water, or water may be used as necessary.
The cleaning method is not particularly limited, and examples thereof include a spray method, a dipping method, a paddle method, a spin method, a brushing method, and a scraping method. Moreover, you may use these washing | cleaning methods together as needed.
The said organic solvent can be used individually or in combination of 2 or more types. In the semi-aqueous cleaning liquid, the concentration of the organic solvent is usually preferably 2 to 90% by mass. The washing temperature is adjusted in accordance with the developability of the core portion forming resin layer.

As processing after development or washing, exposure and / or heating may be performed as necessary from the viewpoint of improving curability and adhesion of the core portion 2. Although there is no restriction | limiting in particular in heating temperature, It is preferable that it is 40-200 degreeC, and although the irradiation amount of actinic light does not have a restriction | limiting in particular, it is preferable that it is 0.01-10 J / cm < ² >.

  As a fifth step, an upper clad layer forming resin film is laminated on the lower clad layer 4 and the core portion 2 by the same method as the first and second steps. Here, the upper clad layer forming resin layer is designed to have a lower refractive index than the core portion forming resin layer. The thickness of the upper clad forming resin layer is preferably larger than the height of the core portion 2.

Next, the upper clad layer forming resin layer is cured by light and / or heat to form the upper clad layer 3 in the same manner as in the first step.
Although there is no restriction | limiting in particular in the irradiation amount of the actinic light at the time of hardening | curing the resin layer for upper clad layer formation with light, It is preferable to set it as 0.1-30 J / cm < ² >. Moreover, when actinic light permeate | transmits a base material, in order to harden | cure efficiently, the double-sided exposure machine which can irradiate actinic light simultaneously from both surfaces can be used. Moreover, you may irradiate actinic light, heating as needed, and you may heat-process as a process before and behind photocuring. The heating temperature during and / or after irradiation with actinic light is not particularly limited, but is preferably 50 to 200 ° C.
The heating temperature when the upper clad layer-forming resin layer is cured by heat is not particularly limited, but is preferably 50 to 200 ° C.
In addition, when the removal of the support film of the resin film for upper clad layer formation is required, you may remove before hardening or after hardening.
The optical waveguide 1 can be manufactured through the above steps.

  The following examples of the present invention will be described more specifically, but the present invention is not limited to these examples.

Synthesis example 1
[Production of (Meth) acrylic polymer A-1]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, 97 parts by mass of propylene glycol monomethyl ether acetate and 32 parts by mass of methyl lactate were weighed and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 30 parts by mass of N-cyclohexylmaleimide, 138 parts by mass of benzyl methacrylate, 39 parts by mass of methacrylic acid, 3 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile), propylene glycol A mixture of 97 parts by mass of monomethyl ether acetate and 32 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour to obtain (meth) acrylic polymer A-1. A solution (solid content 45 mass%) was obtained.

[Measurement of weight average molecular weight]
As a result of measuring the weight average molecular weight (converted to standard polystyrene) of A-1 using GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation), 2.4 × 10 ⁴ . The column used was “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd. Tetrahydrofuran was used as the eluent, the sample concentration was 0.5 mg / ml, and the elution rate was 1 ml / min.

[Measurement of acid value]
As a result of measuring the acid value of A-1, it was 120 mgKOH / g. The acid value was calculated from the amount of 0.1 mol / L potassium hydroxide aqueous solution required to neutralize the A-1 solution. At this time, the point at which the phenolphthalein added as an indicator changed color from colorless to pink was defined as the neutralization point.

Synthesis example 2
[Production of (Meth) acrylic polymer A-2]
96 parts by mass of propylene glycol monomethyl ether acetate and 32 parts by mass of methyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 51 parts by mass of N-cyclohexylmaleimide, 72 parts by mass of cyclohexyl methacrylate, 49 parts by mass of butyl acrylate, 32 parts by mass of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile) A mixture of 4 parts by mass, 96 parts by mass of propylene glycol monomethyl ether acetate and 32 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours and further stirring at 95 ° C. for 1 hour. ) Acrylic polymer A-2 solution (solid content 45 mass%) was obtained.
As a result of measuring the weight average molecular weight and acid value of A-2 by the same method as in Synthesis Example 1, they were 3.5 × 10 ⁴ and 60 mgKOH / g, respectively.

Synthesis example 3
[Production of (Meth) acrylic polymer A-3]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, 97 parts by mass of propylene glycol monomethyl ether acetate and 32 parts by mass of methyl lactate were weighed and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 30 parts by mass of N-cyclohexylmaleimide, 115 parts by mass of benzyl methacrylate, 30 parts by mass of 2-hydroxyethyl methacrylate, 27 parts by mass of methacrylic acid, 2,2′-azobis (2,4-dimethyl (Valeronitrile) A mixture of 4 parts by mass, 97 parts by mass of propylene glycol monomethyl ether acetate and 32 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours and further stirring at 95 ° C. for 1 hour. (Meth) acrylic polymer A-3 solution (solid content 45 mass%) was obtained.
As a result of measuring the weight average molecular weight and acid value of A-3 by the same method as in Synthesis Example 1, they were 2.7 × 10 ⁴ and 100 mgKOH / g, respectively.

Synthesis example 4
[Production of (Meth) acrylic polymer A-4]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel and a thermometer, 108 parts by mass of propylene glycol monomethyl ether acetate and 27 parts by mass of methyl lactate were weighed, and stirring was started while introducing nitrogen gas. The liquid temperature was raised to 80 ° C., N-cyclohexylmaleimide 20 parts by mass, benzyl methacrylate 90 parts by mass, methacrylic acid 39 parts by mass, 2,2′-azobisisobutyronitrile 1 part by mass, propylene glycol monomethyl ether acetate 72 A mixture of parts by mass and 18 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 80 ° C. for 3 hours, further stirring at 120 ° C. for 1 hour, and cooling to room temperature.
Subsequently, 0.07 part by mass of dibutyltin dilaurate was added and stirring was started. The liquid temperature was raised to 50 ° C., a mixture of 23 parts by mass of 2-methacryloyloxyethyl isocyanate and 14 parts by mass of propylene glycol monomethyl ether acetate was added dropwise over 30 minutes, and stirring was continued at 50 ° C. for 3 hours. An acrylic polymer A-4 solution (solid content: 42% by mass) was obtained.
As a result of measuring the weight average molecular weight and acid value of A-4 by the same method as in Synthesis Example 1, they were 4.5 × 10 ⁴ and 100 mgKOH / g, respectively.

Synthesis example 5
[Production of (Meth) acrylic polymer A-5]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel and a thermometer, 108 parts by mass of propylene glycol monomethyl ether acetate and 27 parts by mass of methyl lactate were weighed, and stirring was started while introducing nitrogen gas. The liquid temperature was raised to 80 ° C., 20 parts by mass of N-cyclohexylmaleimide, 47 parts by mass of dicyclopentanyl methacrylate, 59 parts by mass of 2-hydroxyethyl methacrylate, 22 parts by mass of methacrylic acid, 2,2′-azobisisobutyrate. A mixture of 1 part by mass of nitrile, 72 parts by mass of propylene glycol monomethyl ether acetate and 18 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 80 ° C. for 3 hours, and further stirring at 120 ° C. for 1 hour, Cooled to room temperature.
Subsequently, 0.07 part by mass of dibutyltin dilaurate was added and stirring was started. The liquid temperature was raised to 50 ° C., a mixture of 23 parts by mass of 2-methacryloyloxyethyl isocyanate and 14 parts by mass of propylene glycol monomethyl ether acetate was added dropwise over 30 minutes, and stirring was continued at 50 ° C. for 3 hours. An acrylic polymer A-5 solution (solid content: 42% by mass) was obtained.
As a result of measuring the weight average molecular weight and acid value of A-5 by the same method as in Synthesis Example 1, they were 5.4 × 10 ⁴ and 70 mgKOH / g, respectively.

Example 1
[Preparation of resin varnish COV-1 for core formation]
As component (A), 133 parts by mass (solid content: 45% by mass) of the A-1 solution (solid content: 45% by mass), and as component (B), ethoxylated bisphenol A diacrylate (manufactured by Hitachi Chemical Co., Ltd.) 15 parts by mass of “Fancryl FA-324A”) and 15 parts by mass of ethoxylated bisphenol A diacrylate (“Fancryl FA-321A” manufactured by Hitachi Chemical Co., Ltd.), as component (C), bisphenol A type epoxy resin (Japan) Epoxy resin "Epicoat 1001" (epoxy equivalent 475 g / eq)), (D) as component 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propane -1-one ("Irgacure 2959" manufactured by Ciba Japan Co., Ltd.) 1 part by mass, bis (2,4,6-trimethylbenzoy) ) Made phenylphosphine oxide (Ciba Japan KK "Irgacure 819") 1 part by mass, and 10 parts by mass of propylene glycol monomethyl ether acetate were mixed with stirring as dilution solvent. After pressure filtration using a polyflon filter having a pore diameter of 2 μm (“PF020” manufactured by Advantech Toyo Co., Ltd.), degassing was performed under reduced pressure to obtain a resin varnish COV-1 for forming a core part.

[Preparation of Core Part Forming Resin Film COF-1]
The resin varnish COV-1 for forming a core part is coated on a non-treated surface of a PET film (“Cosmo Shine A1517” manufactured by Toyobo Co., Ltd., thickness 16 μm) “Multicoater TM-” manufactured by Hirano Techseed Co., Ltd. MC "), and after drying at 80 ° C for 10 minutes and 100 ° C for 10 minutes, surface release treated PET film (" Purex A31 "manufactured by Teijin DuPont Films Co., Ltd., thickness 25 μm) is used as a protective film. The resin film COF-1 for pasting and core part formation was obtained. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine, but in this example, the thickness after curing is adjusted to be 50 μm in the core portion forming resin film. did.

[Alkali developer solubility evaluation]
The protective film (A31) of the core part-forming resin film COF-1 was removed, and whether or not the resin layer was dissolved in a 1% by mass sodium carbonate aqueous solution was evaluated according to the following criteria.
○: Completely dissolved and no residual resin layer ×… With residual resin layer

[Storage stability evaluation]
After the core part-forming resin film COF-1 was stored at 23 ° C. for 7 days under complete light shielding, whether or not the solubility in a 1 mass% sodium carbonate aqueous solution changed before and after the storage was evaluated according to the following criteria.
○: No change in solubility ×: Reduced solubility

Example 2
[Preparation of Clad Layer Forming Resin Varnish CLV-1]
As component (A), 133 parts by mass of the A-2 solution (solid content 45% by mass) (solid content 60 parts by mass), and as component (B), ethoxylated isocyanuric acid triacrylate (manufactured by Hitachi Chemical Co., Ltd.) 15 parts by mass of “Fancryl FA-721A”) and 15 parts by mass of ethoxylated cyclohexanedimethanol diacrylate (“NK Ester A-CHD-4E” manufactured by Shin-Nakamura Chemical Co., Ltd.), as component (C), hydrogenated bisphenol Type A epoxy resin ("Epicoat YX8034" (epoxy equivalent 290 g / eq) manufactured by Japan Epoxy Resin Co., Ltd.), (D) as component 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2 1 part by weight of methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan Co., Ltd.), bis (2, 4, - trimethyl benzoyl) phenyl phosphine oxide (Ciba Japan Co., Ltd. "Irgacure 819") 1 part by mass, and 10 parts by mass of propylene glycol monomethyl ether acetate were mixed with stirring as dilution solvent. After pressure filtration using a polyflon filter having a pore size of 2 μm (“PF020” manufactured by Advantech Toyo Co., Ltd.), degassing was performed under reduced pressure to obtain a resin varnish CLV-1 for forming a cladding layer.

[Preparation of Cladding Layer Forming Resin Film CLF-1]
The clad layer-forming resin composition CLV-1 was applied on the non-treated surface of a PET film (“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., thickness 50 μm) using the coating machine at 100 ° C. After drying for 20 minutes, a surface release-treated PET film (“Purex A31” manufactured by Teijin DuPont Films Ltd., thickness 25 μm) was attached as a protective film to obtain a resin film CLF-1 for forming a cladding layer. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. In this embodiment, the thickness after curing is 20 μm for the resin film for forming the lower cladding layer, and the upper cladding. In the resin film for layer formation, it adjusted so that it might be set to 60 micrometers.
Subsequently, the alkali developer solubility and storage stability were evaluated in the same manner as in Example 1 using the upper clad layer forming resin film CLF-1.

Examples 3-6 and Comparative Examples 1-4
According to the blending ratio shown in Table 1, core part-forming resin varnishes COV-2 to 8 were prepared, and core part-forming resin films COF-2 to 8 were produced in the same manner as in Example 1.
According to the compounding ratio shown in Table 1, a clad layer forming resin varnish CLV-2 was prepared, and a clad layer forming resin film CLF-2 was produced in the same manner as in Example 2.
Subsequently, using these core part forming resin films COF-2 to 8 and the cladding layer forming resin film CLF-2, the alkali developer solubility and storage stability were evaluated in the same manner as in Example 1. did.

* 1: Propylene glycol monomethyl ether acetate / methyl lactate solution of (meth) acrylic polymer A-1 prepared in Synthesis Example 1 (solid content 45% by mass)
* 2: Propylene glycol monomethyl ether acetate / methyl lactate solution of (meth) acrylic polymer A-2 produced in Synthesis Example 2 (solid content 45% by mass)
* 3: Propylene glycol monomethyl ether acetate / methyl lactate solution of (meth) acrylic polymer A-3 prepared in Synthesis Example 3 (solid content 45% by mass)
* 4: Propylene glycol monomethyl ether acetate / methyl lactate solution of (meth) acrylic polymer A-4 prepared in Synthesis Example 4 (solid content 42% by mass)
* 5: Propylene glycol monomethyl ether acetate / methyl lactate solution of (meth) acrylic polymer A-5 prepared in Synthesis Example 5 (solid content 42 mass%)
* 6: Ethoxylated bisphenol A diacrylate (manufactured by Hitachi Chemical Co., Ltd. “Fancryl FA-324A”)
* 7: Ethoxylated bisphenol A diacrylate (manufactured by Hitachi Chemical Co., Ltd. “Fancryl FA-321A”)
* 8: Ethoxylated isocyanuric acid triacrylate (manufactured by Hitachi Chemical Co., Ltd., “Fancryl FA-731A”)
* 9: Ethoxylated cyclohexanedimethanol diacrylate (Shin Nakamura Chemical Co., Ltd. “NK Ester A-CHD-4E”)
* 10: Ethoxylated bisphenol A diacrylate (“NK Ester A-BPE-6” manufactured by Shin-Nakamura Chemical Co., Ltd.)
* 11: p-cumylphenoxyethyl acrylate (Shin Nakamura Chemical Co., Ltd. “NK Ester A-CMP-1E”)
* 12: Bisphenol A type epoxy resin ("Epicoat 1001" manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 475 g / eq)
* 13: Hydrogenated bisphenol A type epoxy resin (“Epicoat YX8034” manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 290 g / eq)
* 14: Bisphenol F type epoxy resin (“Epototo YDF-2001” manufactured by Toto Kasei Co., Ltd.) (epoxy equivalent 475 g / eq)
* 15: Ethoxylated bisphenol A type epoxy resin (“Rikaresin BEO-60E” manufactured by Shin Nippon Rika Co., Ltd., epoxy equivalent of 365 g / eq)
* 16: Fluorene bisphenol-type epoxy resin (“ONCOAT EX-1020” manufactured by Nagase ChemteX Corporation, epoxy equivalent 305 g / eq)
* 17: Phenol biphenylene type epoxy resin (“NC-3000” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 275 g / eq)
* 18: o-cresol novolac type epoxy resin (“Epototo YDCN-701” manufactured by Toto Kasei Co., Ltd.) (epoxy equivalent 208 g / eq)
* 19: Bisphenol A type epoxy resin ("Epicoat 1007FS" manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 1300 g / eq)
* 20: 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan Co., Ltd.)
* 21: Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (“Irgacure 819” manufactured by Ciba Japan Co., Ltd.)
* 22: 1-cyanoethyl-2-phenylimidazole (“Cureazole 2PZ-CN” manufactured by Shikoku Chemicals Co., Ltd.)
* 23: Propylene glycol monomethyl ether acetate * 24: ○ completely dissolved and no residual resin layer, ×… residual resin layer present * 25: ○ ... no change in solubility, × ... reduced solubility

Example 7
[Production of rigid optical waveguide]
Using a roll laminator (“HLM-1500” manufactured by Hitachi Chemical Technoplant Co., Ltd.), the lower clad layer-forming resin film CLF-1 from which the protective film (A31) was removed was replaced with a glass epoxy resin substrate (Hitachi Chemical Industry ( The film was laminated on “MCL-E-679FB”) manufactured under the conditions of a pressure of 0.5 MPa, a temperature of 80 ° C., and a speed of 0.2 m / min. Furthermore, using a vacuum pressurization type laminator (“MVLP-500 / 600” manufactured by Meiki Seisakusho Co., Ltd.), pressure bonding was performed under the conditions of a pressure of 0.4 MPa, a temperature of 80 ° C., and a pressurization time of 30 seconds.
Next, by using an ultraviolet exposure machine (“MAP-1200-L” manufactured by Dainippon Screen Co., Ltd.), the support film (A4100) is removed by irradiating the ultraviolet rays (wavelength 365 nm) with 2000 mJ / cm ² , A clad layer 4 was formed.

Subsequently, the core part-forming resin film COF-1 from which the protective film (A31) has been removed using the roll laminator is placed on the lower cladding layer 4 at a pressure of 0.5 MPa, a temperature of 80 ° C., and a speed of 0.2 m / second. Lamination was performed under the condition of min. Further, the vacuum pressurizing laminator was used for pressure bonding under conditions of a pressure of 0.4 MPa, a temperature of 80 ° C., and a pressurization time of 30 seconds.
Subsequently, the core part 2 (core pattern) was exposed by irradiating 1000 mJ / cm < ² > of ultraviolet rays (wavelength 365 nm) with the said ultraviolet exposure machine through the negative photomask of 50 micrometers in width. After exposure and heating at 80 ° C. for 5 minutes, the support film (A1517) was removed and developed using a 1% by mass aqueous sodium carbonate solution. Then, it wash | cleaned using the pure water and heat-dried at 100 degreeC for 1 hour.

Next, the upper clad layer forming resin film CLF-1 from which the protective film (A31) has been removed using the vacuum pressurizing laminator is placed on the core 2 and the lower clad layer 4 at a pressure of 0.4 MPa and a temperature of 100. Lamination was performed at a temperature of 30 ° C. and a pressurization time of 30 seconds. After irradiating ultraviolet rays (wavelength 365 nm) at 2000 mJ / cm ² and removing the support film (A4100), the upper clad layer 3 is formed by heating and curing at 160 ° C. for 1 hour, and the light shown in FIG. A waveguide 1 was obtained. Thereafter, a rigid optical waveguide having a length of 10 cm was cut out using a dicing saw (“DAD-341” manufactured by DISCO Corporation).

[Optical propagation loss measurement]
The optical propagation loss of the obtained rigid optical waveguide is determined based on the VCSEL (“FLS-300-01-VCL” manufactured by EXFO) having a light source having a wavelength of 850 nm as a light source and the light receiving sensor (“Q82214” manufactured by Advantest Corporation). ), An input fiber (GI-50 / 125 multimode fiber, NA = 0.20), and an output fiber (SI-114 / 125, NA = 0.22). The optical propagation loss was calculated by dividing the measured optical loss (dB) by the optical waveguide length (10 cm), and was evaluated according to the following criteria.
◎ ... 0.1 dB / cm or less ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less × ... greater than 0.3 dB / cm

[High temperature and high humidity test]
In order to evaluate the environmental reliability, the obtained rigid optical waveguide was subjected to the JPCA standard (JPCA-PE02-05-01S) using a high-temperature and high-humidity tester (“PL-2KT” manufactured by ESPEC Corporation). Under the same conditions, a high-temperature and high-humidity test at a temperature of 85 ° C. and a humidity of 85% was conducted for 1000 hours.
The light propagation loss of the optical waveguide after the high-temperature and high-humidity storage test was measured using the same light source, light receiving element, incident fiber, and output fiber as described above, and evaluated according to the following criteria.
◎ ... 0.1 dB / cm or less ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less × ... greater than 0.3 dB / cm

[Temperature cycle test]
In order to evaluate thermal shock resistance, the obtained rigid optical waveguide was subjected to the JPCA standard (JPCA-PE02-05-01S) using a temperature cycle tester (“ETAC WINTECH NT1010” manufactured by Enomoto Kasei Co., Ltd.). Under the same conditions, 1000 cycles of a temperature cycle test between a temperature of −55 ° C. and 125 ° C. were performed. Detailed temperature cycle test conditions are shown in Table 2.

The light propagation loss of the optical waveguide after the temperature cycle test was measured using the same light source, light receiving element, incident fiber and output fiber as described above, and evaluated according to the following criteria.
◎ ... 0.1 dB / cm or less ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less × ... greater than 0.3 dB / cm

[Reflow test]
In order to evaluate the reflow heat resistance, the obtained rigid optical waveguide was subjected to IPC / JEDEC J-STD-020B using a reflow tester ("Salamanda XNA-645PC" manufactured by Furukawa Electric Co., Ltd.). Under the conditions, a reflow test at a maximum temperature of 265 ° C. was performed three times in a nitrogen atmosphere. Detailed reflow conditions are shown in Table 3, and the temperature profile in the reflow furnace is shown in FIG.

The light propagation loss of the optical waveguide after the reflow test was measured using the same light source, light receiving element, incident fiber and output fiber as described above, and evaluated according to the following criteria.
◎ ... 0.1 dB / cm or less ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less × ... greater than 0.3 dB / cm

[180 ° C, 1 hour heat treatment]
In order to evaluate stability at the time of bonding, the obtained rigid optical waveguide was heat-treated in air at 180 ° C. for 1 hour.
The light propagation loss of the optical waveguide after the heat treatment was measured using the same light source, light receiving element, incident fiber, and outgoing fiber as those described above, and evaluated according to the following criteria.
◎ ... 0.1 dB / cm or less ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less × ... greater than 0.3 dB / cm

Examples 8-11 and Comparative Example 5
A rigid optical waveguide was produced in the same manner as in Example 7 by using the core portion forming resin films COF-2 to 5 and 8 and the clad layer forming resin films CLF-1 and 2.
Subsequently, measurement of light propagation loss of the obtained rigid optical waveguide (length: 10 cm), high-temperature and high-humidity test, temperature cycle test, reflow test, and measurement of light propagation loss after heat treatment at 180 ° C. for 1 hour are examples. The same conditions as in No. 7 were used.
The results are shown in Table 4.

* 1: ◎ ... 0.1 dB / cm or less, ○ ... greater than 0.1 dB / cm, 0.2 dB / cm or less, Δ ... greater than 0.2 dB / cm, 0.3 dB / cm or less, x ... 0. Greater than 3dB / cm

  From Table 1 and Table 4, the resin composition for forming an optical waveguide of the present invention is excellent in transparency, heat resistance, alkali developability, and storage stability, and the optical waveguide produced using these is transparent, It turns out that it is excellent in environmental reliability and heat resistance. On the other hand, although the resin composition for optical waveguide formation which does not belong to this invention shown in the comparative example 1 is excellent in alkali developability, it turns out that it is inferior in storage stability. Moreover, the resin composition for optical waveguide formation which does not belong to this invention shown in Comparative Example 2 is inferior in alkali developability, and the optical waveguide which does not belong to this invention shown in Comparative Example 5 is inferior in stability at the time of bonding. I understand that.

  The resin composition for forming an optical waveguide of the present invention is excellent in transparency, heat resistance, alkali developability, and storage stability, and an optical waveguide produced using these has transparency, environmental reliability, and heat resistance. It is an excellent one. In addition, the optical waveguide forming resin film using the optical waveguide forming resin composition has a flatness of each layer, interlayer adhesion between a clad and a core, and resolution at the time of forming an optical waveguide core pattern in an optical waveguide manufacturing process. (Narrow line or narrow line compatibility) is further improved, flatness is excellent, and it is possible to form a fine pattern with a small line width and line.

DESCRIPTION OF SYMBOLS 1 Optical waveguide 2 Core part 3 Upper clad layer 4 Lower clad layer 5 Base material

Claims (15)

  (A) a polymer having a carboxyl group, (B) a compound having an ethylenically unsaturated group, (C) a compound having two or more epoxy groups in the molecule and having an epoxy equivalent of 250 to 1000 g / eq, And (D) a resin composition for forming an optical waveguide containing a radical polymerization initiator. The resin composition for forming an optical waveguide according to claim 1, wherein the component (A) includes a (meth) acrylic polymer having a structural unit represented by the following general formulas (1) and (2).

(In the formula, each R ¹ independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R ² represents a hydrogen atom or a methyl group, and X ¹ represents a single bond or 1 to 20 carbon atoms. Indicates a divalent organic group.)

(In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a monovalent organic group having 1 to 20 carbon atoms.) The resin composition for forming an optical waveguide according to claim 2, wherein the component (A) further has a structural unit represented by the following general formula (3).

(In the formula, R ⁵ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.)   The optical waveguide according to claim 1, wherein the component (B) is a compound containing in the molecule at least one selected from the group consisting of an alicyclic structure, an aromatic ring structure, and a heterocyclic structure. Resin composition for forming.   The resin composition for forming an optical waveguide according to claim 1, wherein the component (B) is (meth) acrylate. The resin composition for forming an optical waveguide according to claim 1, wherein the component (B) contains at least one of (meth) acrylates represented by the following general formulas (4) to (6).

(In the formula, R ⁶ represents a hydrogen atom or a methyl group. R ⁷ represents

The monovalent group of any of these is shown. R ⁸ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. Z ¹ is a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ —,

The bivalent group of any of these is shown. R ⁹ represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. a represents an integer of 2 to 10. Y ¹ is an oxygen atom, a sulfur _{atom, -OCH 2 -, - SCH 2} -, - O (CH 2 CH 2 O) b -, - O [CH (CH 3) CH 2 O] c -, - O [CH ₂ CH (CH ₃ ) O] _d —, —O [(CH ₂ ) ₅ CO ₂ ] _e —, and —OCH ₂ CH (OH) CH ₂ O— are included. be represents an integer of 1 to 10. )

(In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, and may be the same or different. R ¹¹ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms; Z ² may be the same or different, Z ² represents a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, — SO ₂ −,

The bivalent group of any of these is shown. R ¹² represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms, and may be the same or different. f shows the integer of 2-10. Y ² represents an oxygen atom, a sulfur _{atom, -OCH 2 -, - SCH 2} -, - O (CH 2 CH 2 O) g -, - O [CH (CH 3) CH 2 O] h -, - O [CH ₂ CH (CH ₃ ) O] _i — and —O [(CH ₂ ) ₅ CO ₂ ] _j — are included. g to j each independently represents an integer of 1 to 10. )

(In the formula, k represents an integer of 1 to 10. R ¹³ represents a hydrogen atom or a methyl group, and may be the same or different. R ¹⁴ represents a hydrogen atom, a fluorine atom, and a carbon number of 1 to 20. Any of monovalent organic groups, which may be the same or different, Z ³ represents a single bond, an oxygen atom, a sulfur atom, —CH ₂ —, —C (CH ₃ ) ₂ —, —CF ₂ —, _{-C (CF 3) 2 -,} - SO 2 -,

The bivalent group of any of these is shown. R ¹⁵ represents any one of a hydrogen atom, a fluorine atom, and a monovalent organic group having 1 to 20 carbon atoms. l represents an integer of 2 to 10. Y ³ represents an oxygen atom, a sulfur atom, —O (CH ₂ CH ₂ O) _m —, —O [CH (CH ₃ ) CH ₂ O] _n —, —O [CH ₂ CH (CH ₃ ) O] _o —. , and _{-O [(CH 2) 5 CO} 2] p - including any divalent group. m to p each independently represents an integer of 1 to 10. )   The optical waveguide according to claim 1, wherein the component (C) is a compound containing in the molecule at least one selected from the group consisting of an alicyclic structure, an aromatic ring structure, and a heterocyclic structure. Resin composition for forming.   The resin composition for forming an optical waveguide according to claim 1, wherein the component (D) contains a radical photopolymerization initiator.   The blending amount of the component (A) is 30 to 85% by mass with respect to the total amount of the components (A) to (C), and the blending amount of the component (B) is the total amount of the components (A) to (C). The blending amount of the component (C) is 1 to 40% by weight with respect to the total amount of the components (A) to (C), and the blending amount of the component (D) is ( It is 0.01-10 mass parts with respect to 100 mass parts of total amounts of A)-(C) component, The resin composition for optical waveguide formation in any one of Claims 1-8.   Furthermore, (E) The resin composition for optical waveguide formation in any one of Claims 1-9 containing a hardening accelerator.   The compounding quantity of the said (E) component is 0.01-10 mass parts with respect to 100 mass parts of total amounts of (A)-(C) component, The resin composition for optical waveguide formation of Claim 10.   The resin film for optical waveguide formation formed using the resin composition for optical waveguide formation in any one of Claims 1-11.   The optical waveguide which has a core part and / or a clad layer formed using the resin composition for optical waveguide formation in any one of Claims 1-11.   An optical waveguide having a core portion and / or a cladding layer formed using the resin film for forming an optical waveguide according to claim 12.   The optical waveguide according to claim 13 or 14, wherein a light propagation loss in a light source having a wavelength of 850 nm is 0.3 dB / cm or less.

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