JP2008249753A - Film optical waveguide - Google Patents

Abstract

A film-like optical waveguide capable of suppressing deformation at high temperatures is provided.
A film-shaped optical waveguide 1 including a lower clad layer 2, a core portion 3, and an upper clad layer 4, wherein (A) 2 is formed on at least one outer surface of the lower clad layer 2 and the upper clad layer 4. Multifunctional epoxy monomer (excluding those having a (meth) acryloyl group), (B) Bifunctional or polyfunctional oxetane monomer, (C) At least one (meth) in one molecule A polyimide film layer 7 through a cured film 5, 6 of a composition for radiation curable adhesive comprising an acryloyl group, a compound having at least one epoxy group, and (D) a cationic photopolymerization initiator. A film-shaped optical waveguide 1 having 8.
[Selection] Figure 1

Description

  The present invention relates to a film-shaped optical waveguide.

In the multimedia era, optical waveguides are attracting attention as optical transmission media because of the demand for large capacity and high speed information processing in optical communication systems and computers. A quartz optical waveguide, which is a typical example of a conventional optical waveguide, is generally manufactured by the following steps (1) to (3).
(1) A lower cladding layer made of a glass film is formed on a silicon substrate by a technique such as flame deposition (FHD) or CVD.
(2) An inorganic thin film having a higher refractive index is formed on the lower cladding layer, and the thin film is patterned by reactive ion etching (RIE) to form a core portion.
(3) Further, an upper clad layer is formed by a flame deposition method.
However, such a method for manufacturing a silica-based optical waveguide has problems such as requiring a special manufacturing apparatus and a long manufacturing time.

In order to solve these problems, a predetermined amount of light is irradiated to a predetermined portion of the silicone composition containing a photopolymerizable component to cure the portion, and then the unexposed portion is developed. Thus, a method of manufacturing an optical waveguide by forming a core portion or the like has been proposed (Patent Document 1).
This method is advantageous in that the optical waveguide can be manufactured in a short time and at a low cost as compared with the conventional method for manufacturing a silica-based optical waveguide. However, this method has limitations such as the need to use a special silicone-based oligomer.
On the other hand, (A) a vinyl polymer having a carboxyl group, a polymerizable group and other organic groups, (B) a compound having two or more polymerizable reactive groups in the molecule, and (C) a radiation polymerization initiator. , A radiation curable composition for forming an optical waveguide has been proposed (Patent Document 2).
JP 2000-180643 A JP 2003-195079 A

According to the knowledge found by the present inventors, a film-shaped optical waveguide formed using a radiation-curable composition for forming an optical waveguide containing the above-mentioned components (A) to (C) has a heat resistance such as deformation at high temperatures. There is a problem of inferiority.
Then, an object of this invention is to provide the film-form optical waveguide which can suppress a deformation | transformation under high temperature.

  As a result of intensive studies to solve the above problems, the present inventor has (A) a bifunctional or higher polyfunctional epoxy monomer on the outer surface of at least one of the lower clad layer and the upper clad layer constituting the film-shaped optical waveguide. (Excluding those having a (meth) acryloyl group), (B) a bifunctional or higher polyfunctional oxetane monomer, (C) at least one (meth) acryloyl group in one molecule, and at least 1 If a polyimide film layer is formed through a cured film of a radiation curable adhesive composition comprising a compound having at least one epoxy group and (D) a cationic photopolymerization initiator, a polyimide film layer and Deformation of the film-like optical waveguide at high temperatures can be suppressed without causing separation from the optical waveguide body (lower cladding layer, core portion, and upper cladding layer). Headlines, and completed the present invention.

That is, the present invention provides the following [1] to [4].
[1] A film-shaped optical waveguide including a lower clad layer, a core portion, and an upper clad layer, wherein at least one outer surface of the lower clad layer and the upper clad layer has the following components (A) to (D) A film-like optical waveguide comprising a polyimide film layer through a cured film of the radiation-curable adhesive composition.
(A) Bifunctional or higher polyfunctional epoxy monomer (excluding those having a (meth) acryloyl group)
(B) Bifunctional or higher polyfunctional oxetane monomer (C) Compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule (D) Cationic photopolymerization initiator [2] The above [1], wherein each of the lower clad layer and the upper clad layer is obtained by curing a radiation curable composition containing a monomer having a (meth) acryloyl group and a radical polymerizable initiator. Film-shaped optical waveguide.
[3] The film-shaped optical waveguide according to [1] or [2], wherein the content of the components (A) to (D) with respect to the total amount of the radiation curable adhesive composition is as follows.
(A) Bifunctional or higher polyfunctional epoxy monomer (excluding those having a (meth) acryloyl group) 10 to 50% by mass
(B) Bifunctional or higher polyfunctional oxetane monomer 10 to 50% by mass
(C) 1 to 45% by mass of a compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule;
(D) Cationic photopolymerization initiator 0.1 to 10% by mass.
[4] The film-shaped optical waveguide according to any one of [1] to [3], wherein the polyimide film layer is formed of a polyimide film having a corona discharge-treated surface.

  According to the present invention, it is possible to suppress deformation of the film-like optical waveguide at a high temperature without causing separation between the polyimide film layer and the optical waveguide body.

（式中、Ｒ^１及びＲ^２は各々独立して水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイル基であり、Ｘは単結合又は２価の有機基であり、Ｙは重合性を有しない有機基である。）
一般式（１）、（２）中のＲ^１及びＲ^２は、各々独立して、水素原子又は炭素数１〜１２のアルキル基であり、好ましくは、水素原子又は炭素数１〜５のアルキル基であり、より好ましくは、水素原子又はメチル基である。 The film-form optical waveguide of the present invention is a film-form optical waveguide including a lower clad layer, a core portion, and an upper clad layer, and a radiation curable adhesive on at least one outer surface of the lower clad layer and the upper clad layer. It has a polyimide film layer through the cured film of the composition for medical use.
In addition, the part which consists of a lower clad layer, a core part, and an upper clad layer is called "optical waveguide main body" in this specification.
[1. Optical waveguide body]
A preferred example of the radiation curable composition and / or thermosetting composition (hereinafter also referred to as “optical waveguide forming composition”) for forming the optical waveguide body is a simple substance having a (meth) acryloyl group. A composition comprising a monomer and a radical polymerization initiator.
Preferable examples of the composition containing a monomer having a (meth) acryloyl group and a radical polymerization initiator include those containing the following components (A1) to (D1) and other optional components.
[(A1) component]
The component (A1) used as the material of the optical waveguide body is a polymer (for example, a random copolymer) containing repeating units represented by the following general formulas (1) and (2).

Wherein R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyl group, and X is a single bond or a divalent organic group. And Y is an organic group having no polymerizability.)
R ¹ and R ² in the general formulas (1) and (2) are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, preferably a hydrogen atom or an alkyl having 1 to 5 carbon atoms. A group, more preferably a hydrogen atom or a methyl group.

（式中、Ｒ^１は水素原子又は炭素数１〜１２のアルキル基であり、Ｒ^３は（メタ）アクリロイルオキシ基であり、Ｗ及びＺは各々独立して単結合又は２価の有機基である。）
ここで、一般式（３）中のＷ（２価の有機基）の例としては、下記一般式（４）で表される構造や、フェニレン基等が挙げられる。

（式中、Ｒ^４はメチレンまたは炭素数２〜８のアルキレン基である。）
一般式（３）中のＺ（２価の有機基）の例としては、−（ＣＨ_２）_ｎ−Ｏ−（式中、ｎは１〜８の整数である。）等が挙げられる。 Preferable examples of the repeating unit represented by the general formula (1) include a repeating unit represented by the following general formula (3).

(Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ³ is a (meth) acryloyloxy group, and W and Z are each independently a single bond or a divalent organic group. is there.)
Here, examples of W (divalent organic group) in the general formula (3) include a structure represented by the following general formula (4), a phenylene group, and the like.

(In the formula, R ⁴ is methylene or an alkylene group having 2 to 8 carbon atoms.)
Examples of Z (divalent organic group) in the general formula (3) include — (CH ₂ ) _n —O— (wherein n is an integer of 1 to 8).

（式中、Ｒ^５は炭素数１〜２０の直鎖状、分岐状又は環状の炭素鎖を有する基である。） Examples of Y in the general formula (2) include a structure represented by the following general formula (5), a phenyl group, a cyclic amide group, a pyridyl group, and the like.

(In the formula, R ⁵ is a group having a linear, branched or cyclic carbon chain having 1 to 20 carbon atoms.)

The weight average molecular weight in terms of polystyrene of the component (A1) is preferably 5,000 to 100,000, more preferably 8,000 to 70,000, and particularly preferably 10,000 to 50,000. When the value is less than 5,000, the viscosity of the composition becomes small, and it may be difficult to form a composition layer having a certain thickness. When the value exceeds 100,000, there are disadvantages such as an increase in the viscosity of the composition and poor applicability of the composition.
As the method for producing the component (A1), for example, the radically polymerizable compound (a) having a hydroxyl group and the component (b) (radically polymerizable compound corresponding to the general formula (2)) were radically polymerized in a solvent. Then, the method of adding the isocyanate which has (c) (meth) acryloyloxy group with respect to the hydroxyl group of the side chain of the obtained copolymer is mentioned.
The compounds (a) to (c) used in this method will be described.

The compound (a) (radical polymerizable compound having a hydroxyl group) reacts with a hydroxyl group in the compound and an isocyanate group (—N═C═O) in the compound (c) to form a urethane bond (—NH—COO). -) And a structural unit having a side chain portion containing a (meth) acryloyloxy group derived from the compound (c) is used to introduce into the component (A).
Examples of the compound (a) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxymethyl (meth) acrylate, and 4-hydroxycyclohexyl (meth). An acrylate etc. are mentioned.
A compound (a) is used individually by 1 type or in combination of 2 or more types.
The content of the compound (a) in the component (A1) is preferably 3 to 80% by mass, more preferably 7 to 60% by mass, and particularly preferably 10 to 40% by mass. When the content is less than 3% by mass, curing tends to be insufficient. If the content exceeds 80% by mass, it may be difficult to adjust the refractive index.

The compound (b) (compound corresponding to the structure of the general formula (2)) is mainly used to moderately control the mechanical properties and the like of the component (A1).
Examples of the compound (b) include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, and t-butyl (meth) acrylate. (Meth) acrylic acid alkyl esters such as dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate and other esters of (meth) acrylic acid and cyclic hydrocarbon compounds; phenyl (meth) acrylate, benzyl ( (Meth) acrylate aryl esters such as (meth) acrylate, o-phenylphenol glycidyl ether (meth) acrylate, p-cumylphenoxyethylene glycol acrylate; tribromophenol ethoxy (meth) acrylate, 2,2,2-to Halogenation of fluoromethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate and the like ( (Meth) acrylic acid esters; aromatic vinyls such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene; 1,3-butadiene, isoprene, 1,4- Conjugated diolefins such as dimethylbutadiene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; and fatty acid vinyls such as vinyl acetate.
Of these, dicyclopentanyl (meth) acrylate, methyl (meth) acrylate, n-butyl (meth) acrylate, styrene, α-methylstyrene and the like are preferably used.
A compound (b) is used individually by 1 type or in combination of 2 or more types.
The content of the compound (b) in the component (A1) is preferably 15 to 92% by mass, more preferably 25 to 84% by mass, and particularly preferably 35 to 78% by mass. If the content is less than 15% by mass, it may be difficult to adjust the refractive index. If the content exceeds 92% by mass, curing tends to be insufficient.

Examples of the compound (c) (isocyanate having a (meth) acryloyloxy group) include 2-methacryloxyethyl isocyanate, N-methacryloyl isocyanate, methacryloxymethyl isocyanate, 2-acryloxyethyl isocyanate, N-acryloyl isocyanate, acryl Examples include loxymethyl isocyanate.
The content of the compound (c) in the component (A1) is preferably 5 to 80% by mass, more preferably 9 to 60% by mass, and particularly preferably 12 to 45% by mass. When the content is less than 5% by mass, curing tends to be insufficient. If the content exceeds 80% by mass, it may be difficult to adjust the refractive index.

  In the component (A1), structural units not described in the general formulas (1) and (2) can also be included. Examples of the compound for introducing such a structural unit (hereinafter referred to as compound (d)) include dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; vinyl chloride, vinylidene chloride and the like. And a chlorine-containing polymerizable compound. (A1) The content rate of the compound (d) in a component becomes like this. Preferably it is 0-20 mass%, More preferably, it is 0-10 mass%.

In the process of producing the component (A1), various additives such as a thermal polymerization inhibitor, a storage stabilizer, and a curing catalyst can be added during the addition reaction of the compound (c).
The thermal polymerization inhibitor is blended in order to suppress a polymerization reaction due to heat. Examples of thermal polymerization inhibitors include pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methoxyphenol, amylquinone, amyloxyhydroquinone, n-butylphenol, phenol, hydroquinone monopropyl ether and the like.
Examples of the storage stabilizer include 2,6-di-t-butyl-p-cresol, benzoquinone, p-toluquinone, p-xyloquinone, phenyl-α-naphthylamine and the like.
Examples of the curing catalyst include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioleate, dibutyltin diacetate, tetramethoxytitanium, tetraethoxytitanium and the like.
The total compounding amount of these various additives is usually 10 parts by mass or less, preferably 5 parts by mass or less with respect to 100 parts by mass of the total amount of the compounds (a) to (c).

Examples of the solvent that can be used for radical polymerization of the compound (a), the compound (b), and the compound (d) used as necessary in the production of the component (A1) include methanol, ethanol, ethylene glycol, diethylene glycol, Alcohols such as propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl Ether, diethylene glycol ethyl methyl ether, propylene glycol monomer Alkyl ethers of polyhydric alcohols such as ether and propylene glycol monoethyl ether; alkyl ether acetates of polyhydric alcohols such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate and propylene glycol monomethyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol; ethyl acetate, butyl acetate, ethyl lactate, Ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 2-hydroxy-2-methylpropio Ethyl acetate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, etc. Examples include esters.
Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferred.
On the other hand, if a solvent having a hydroxyl group in the molecule is used as the solvent used in the addition reaction of compound (c) in the production of component (A1), compound (c) reacts with the solvent, which is not preferable. . Therefore, the solvent used for the addition reaction of compound (c) is preferably one having no hydroxyl group. Examples of the solvent having no hydroxyl group include those having no hydroxyl group among the solvents used for the radical polymerization.

  Moreover, as a catalyst for radical polymerization used for manufacture of (A1) component, a normal radical polymerization initiator can be used. Examples of radical polymerization initiators include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2, Azo compounds such as 4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis (t-butylperoxy) cyclohexane; and hydrogen peroxide Can be mentioned. When a peroxide is used as the radical polymerization initiator, a redox initiator may be used in combination with a reducing agent.

[(B1) component]
The component (B1) used as the material of the optical waveguide main body includes a linear structure having a urethane bond repeatedly generated by reaction of a polyol compound and a polyisocyanate compound, and 2 to 6 (meth) acryloyl groups. It is a compound which has this.
The component (B1) is obtained, for example, by reacting a polyol compound, a polyisocyanate compound, and a hydroxyl group-containing (meth) acrylate.
As a manufacturing method of (B1) component, the following manufacturing methods 1-4 are mentioned, for example.
Production method 1: A method in which a polyol compound, a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are charged and reacted together.
Production method 2: A method in which a polyol compound and a polyisocyanate compound are reacted and then a hydroxyl group-containing (meth) acrylate is reacted.
Production method 3: A method in which a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are reacted, and then a polyol compound is reacted.
Production Method 4: A method in which a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate are reacted, then a polyol compound is reacted, and finally, a hydroxyl group-containing (meth) acrylate is reacted again.
Among production methods 1 to 4, production methods 2 to 4 are preferable for controlling the molecular weight distribution.

(1) Polyol compound The polyol compound which is one of the raw materials of the component (B1) is a compound having two or more hydroxyl groups in the molecule. Examples of such compounds include aromatic polyether polyols, aliphatic polyether polyols, alicyclic polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, and the like.
Aromatic polyether polyols include bisphenol A ethylene oxide addition diol, bisphenol A propylene oxide addition diol, bisphenol A butylene oxide addition diol, bisphenol F ethylene oxide addition diol, bisphenol F propylene oxide addition diol, bisphenol F Propylene oxide addition diol, hydroquinone alkylene oxide addition diol, naphthoquinone alkylene oxide addition diol, and the like. As a commercial item, Uniol, DA700, DA1000 (above, Nippon Oil & Fats Corporation) etc. are mentioned, for example.
The aliphatic polyether polyol includes at least one compound selected from ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, substituted tetrahydrofuran, oxetane, substituted oxetane, tetrahydropyran, and oxeban. Examples thereof include those obtained by ring-opening (co) polymerization. Specific examples include polyethylene glycol, 1,2-polypropylene glycol, 1,3-polypropylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, polyisobutylene glycol, copolymer polyol of propylene oxide and tetrahydrofuran, ethylene Copolymer polyol of oxide and tetrahydrofuran, copolymer polyol of ethylene oxide and propylene oxide, copolymer polyol of tetrahydrofuran and 3-methyltetrahydrofuran, copolymer polyol of ethylene oxide and 1,2-butylene oxide .

Examples of the alicyclic polyether polyol include hydrogenated bisphenol A ethylene oxide addition diol, hydrogenated bisphenol A propylene oxide addition diol, hydrogenated bisphenol A butylene oxide addition diol, and hydrogenated bisphenol F ethylene oxide addition diol. And propylene oxide addition diol of hydrogenated bisphenol F, butylene oxide addition diol of hydrogenated bisphenol F, dimethylol compound of dicyclopentadiene, tricyclodecane dimethanol and the like.
Examples of commercially available products of aliphatic polyether polyol and alicyclic polyether polyol include Unisafe DC1100, Unisafe DC1800, Unisafe DCB1100, Unisafe DCB1800 (manufactured by NOF Corporation); PPTG4000, PPTG2000, PPTG1000, PTG2000, PTG3000, PTG650. PTGL2000, PTGL1000 (above, manufactured by Hodogaya Chemical Co., Ltd.); 3201, 4200, 6300, 8200 (above, Sumika Bayer Urethane Co., Ltd.); NPML -2002, 3002, 4002, 8002 (above, manufactured by Asahi Glass Co., Ltd.).

Examples of the polyester polyol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 3-methyl- Polyhydric alcohols such as 1,5-pentanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, Examples thereof include polyester polyols obtained by reacting with polybasic acids such as sebacic acid. As a commercial product, Kurapol P-2010, PMIPA, PKA-A, PKA-A2, PNA-2000, etc. (above, manufactured by Kuraray Co., Ltd.) are available.
Examples of the polycarbonate polyol include 1,6-hexane polycarbonate. Commercially available products include DN-980, 981, 982, 983 (above, manufactured by Nippon Polyurethane Co., Ltd.), PLACEL-CD205, CD-983, CD220 (above, manufactured by Daicel Chemical Industries), PC-8000 (produced by PPG, USA). Etc. are available.

As polycaprolactone polyol, ε-caprolactone, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, 1,6-hexanediol, neopentyl glycol Polycaprolactone diol obtained by reacting with diols such as 1,4-cyclohexanedimethanol and 1,4-butanediol. As commercially available products, PLACC CEL205, 205AL, 212, 212AL, 220, 220AL (manufactured by Daicel Chemical Industries, Ltd.) can be obtained.
Other polyol compounds that can be used in the present invention include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedi Examples include methanol, poly β-methyl-δ-valerolactone, hydroxy-terminated polybutadiene, hydroxy-terminated hydrogenated polybutadiene, castor oil-modified polyol, polydimethylsiloxane-terminated diol compound, and polydimethylsiloxane carbitol-modified polyol.
Among the polyol compounds, polypropylene glycol, ethylene oxide / propylene oxide copolymer diol, ethylene oxide / 1,2-butylene oxide copolymer diol, and propylene oxide / tetrahydrofuran copolymer diol are preferable, and ethylene oxide / 1,2-butylene. An oxide copolymer diol is more preferred.

  The number average molecular weight of the polyol compound is preferably 400 to 10,000, more preferably 1,000 to 8,000, and most preferably 1,500 to 5,000. When the number average molecular weight is less than 400, the Young's modulus of the cured product at normal temperature and low temperature is increased, and it becomes difficult to obtain sufficient bending resistance. On the other hand, when the number average molecular weight exceeds 10,000, the viscosity of the composition increases, and the coating property of the composition may deteriorate.

(2) Polyisocyanate compound The polyisocyanate compound which is one of the raw materials of the component (B1) is a compound having two or more isocyanate groups in the molecule. Examples of such compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, and m-phenylene. Diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1,6 -Hexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, Diisocyanate compounds such as (2-isocyanatoethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, etc. Can be mentioned.
Of these, hydrogenated xylylene diisocyanate, isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and the like are preferable. These polyisocyanate compounds may be used alone or in combination of two or more.

(3) Hydroxyl group-containing (meth) acrylate (B1) Hydroxyl group-containing (meth) acrylate, which is one of the raw materials, is a compound having a hydroxyl group and a (meth) acryloyl group in the molecule. Examples of such compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4 -Hydroxybutyl (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di ( And (meth) acrylate, trimethylolethane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like. Furthermore, the compound obtained by addition reaction of a glycidyl group containing compound and (meth) acrylic acid, such as alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate, is mentioned.
Of these, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like are preferable.
(B) The compounding ratio of each raw material which comprises a component is a polyol compound 0.5-2 mol and a polyisocyanate compound 1-22.5 mol with respect to 1 mol of hydroxyl-containing (meth) acrylates, for example.

The number average molecular weight (polystyrene conversion value measured by gel permeation chromatography) of the component (B1) is preferably 1,000 to 100,000, more preferably 3,000 to 60,000, particularly preferably 5,000. ~ 30,000. When the number average molecular weight is less than 1,000, it is difficult to obtain sufficient bending resistance for a cured product (eg, a clad layer) of the composition. Moreover, when the number average molecular weight exceeds 100,000, the viscosity of the composition becomes too high, and the coating property of the composition may be deteriorated. The component (B1) in the composition for forming an optical waveguide body The blending amount is preferably 10 to 100 parts by mass, more preferably 20 to 80 parts by mass, and particularly preferably 35 to 70 parts by mass with respect to 100 parts by mass of the component (A1). When the amount is less than 10 parts by mass, sufficient bending resistance may not be obtained for the cured product (eg, clad layer) of the composition. When the amount exceeds 100 parts by mass, component (A1) May become poor, resulting in film roughness on the surface of a cured product (eg, a clad layer) of the composition, or insufficient transparency.

[(C1) component]
The component (C1) which is a material of the optical waveguide body is a compound having one or more ethylenically unsaturated groups in the molecule.
The component (C1) preferably has a boiling point of 130 ° C. or higher at 0.1 MPa.
Here, examples of the ethylenically unsaturated group include a (meth) acryloyl group and a vinyl group.
The molecular weight of the component (C1) is preferably less than 2,000, more preferably less than 1,000.
Preferred examples of the component (C1) having two or more ethylenically unsaturated groups in the molecule include two or more (meth) acryloyl groups and / or vinyl groups in the molecule, and a molecular weight of less than 1,000 The compound of this is mentioned.
In this case, all of the ethylenically unsaturated groups in the molecule may be any one of acryloyl group, methacryloyl group and vinyl group, or acryloyl group and methacryloyl group, acryloyl group and vinyl group, methacryloyl group. And a combination of any two of vinyl group, or a combination of three types of acryloyl group, methacryloyl group and vinyl group.

Examples of (meth) acrylates having two (meth) acryloyl groups in the molecule include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4 -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, bis (hydroxymethyl) ) Addition of tricyclodecane di (meth) acrylate, di (meth) acrylate of diol which is an adduct of bisphenol A ethylene oxide or propylene oxide, addition of ethylene oxide or propylene oxide of hydrogenated bisphenol A Di (meth) acrylate of diol, epoxy (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether of bisphenol A, diacrylate of polyoxyalkylenated bisphenol A, 9,9-bis [4- ( 2-acryloyloxyethoxy) phenyl] fluorene and the like.
Examples of (meth) acrylates having 3 or more (meth) acryloyl groups in the molecule include compounds in which 3 mol or more of (meth) acrylic acid is ester-bonded to a polyhydric alcohol having 3 or more hydroxyl groups, for example, Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate Etc.
Moreover, polyether acrylic oligomer, polyester acrylic oligomer, or polyepoxy acrylic oligomer having polyether or polyester in the main chain can also be used.

  Examples of (meth) acrylate having one (meth) acryloyl group in the molecule include dimethylaminoethyl (meth) acrylate, acryloylmorpholine, dimethylacrylamide, diethylacrylamide, diisopropylacrylamide, diacetoneacrylamide, and isobutoxymethyl. (Meth) acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, isobornyl (meth) acrylate, dicyclopentenyl acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 3-hydroxy-1 -Adamantyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate , Cyclohexyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, tricyclo Decanyl (meth) acrylate, 2-acryloylcyclohexyl succinic acid, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, butoxyethyl (meth) acrylate, alkyl alcohol (1-8 carbon atoms) ) Of (meth) acrylate of alcohol which is an adduct of ethylene oxide, (meth) acrylate of alcohol which is an adduct of ethylene oxide of phenol, p-cumylphenol (Meth) acrylate of alcohol which is an adduct of tylene oxide, (meth) acrylate of alcohol which is an adduct of ethylene oxide of nonylphenol, o-phenylphenol glycidyl ether (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-phenoxyethyl ( (Meth) acrylate, ethyl carbitol (meth) acrylate, 2-ethylhexyl (meth) acrylate, 3-hydroxycyclohexyl acrylate, tribromophenol ethoxy (meth) acrylate Rate, 2,2,2-trifluoromethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, perfluorooctylethyl (Meth) acrylate etc. are mentioned.

As these commercial products, Iupimer UV SA1002, SA2007 (above, manufactured by Mitsubishi Chemical Corporation), Biscote # 150, # 155, # 160, # 190, # 192, # 195, # 230, # 215, # 260, # 260 295, # 300, # 335HP, # 360, # 400, # 540, # 700, 3F, 3FM, 4F, 8F, 8FM, 2-MTA, 2-ETA, V-MTG, 3PA, GPT, HEA, HPA, 4-HBA, AIB, IOAA, LA, STA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), light ester M, E, NB, IB, EH, ID, L, L-7, TD, L-8, S , 130MA, 041MA, CH, THF, BZ, PO, IB-X, HO, HOP, HOA, HOP-A, HOB, DM, DE, HO-MS, EG, 2EG, 1.4BG, 1.6HX, 1.9ND, 1.10DC, TMP, G-101P, G-201P, BP-2EM, BP-4EM, BP-6EM, MTG, BO, BC, 3EG, 4EG, 9EG, 14EG, NP, FM-108, G-201P, light acrylate IO-A, HOB-A, TMP-3EO-A, FA-108, IAA, LA, SA, BO-A, EC-A, MTG-A, 130A, DPM-A, PO-A, P-200A, NP-4EA, NP-8EA, THF-A, IB-XA, HOA, HOP-A, M-600A, HOA-MS, 3EG-A, 4EG- A, 9EG-A, 14EG-A, NP-A, MPD-A, 1.6HX-A, BEPG-A, 1.9ND-A, MOD-A, DCP-A, BP-4EA, BP-4PA, BP-10EA, MP-A, TMP-6EO-3A, PE-3A, PE-4A, DPE-6A, BA-104, BA-134 (manufactured by Kyoeisha Chemical Co.), KAYARAD
MANDA, HX-220, HX-620, R-551, R-712, R-604, R-684, PET-30, GPO-303, TMPTA, DPHA, D-310, D-330, DPCA-20, -30, -60, -120 (Nippon Kayaku Co., Ltd.), Aronix M208, M210, M215, M220, M240, M305, M309, M310, M315, M325, M400, M1200, M6100, M6200, M6250, M7100 M8030, M8060, M8100, M8530, M8560, M9050 (above, manufactured by Toagosei Co., Ltd.), NK ester # 401P, NK ester A-BPEF, NK ester A-CMP-1E (above, manufactured by Shin-Nakamura Chemical Co., Ltd.), New Frontier BR-31 (Daiichi Kogyo Seiyaku Co., Ltd.), Lipoxy VR-77, VR-60, VR-90 (manufactured by Showa Polymer Co., Ltd.), Ebecryl 81, 83, 600, 629, 645, 745, 754, 767, 701, 755, 705, 770, 800, 805, 810, 830, 450, 1830, 1870 (manufactured by Daicel UCB), beam sets 575, 551B, 502H, 102 (manufactured by Arakawa Chemical Co., Ltd.), adamantate HA, HM (manufactured by Idemitsu Kosan Co., Ltd.), etc. Is mentioned.
(C1) A component is used individually by 1 type or in combination of 2 or more types.
(C1) The compounding quantity of a component becomes like this. Preferably it is 5-100 mass parts with respect to 100 mass parts of (A1) component, More preferably, it is 10-70 mass parts, Most preferably, it is 20-50 mass parts. When the amount is less than 5 parts by mass, the accuracy of the shape of the target waveguide may be inferior when the optical waveguide body is formed. When the amount exceeds 100 parts by mass, the component (A1) Compatibility may deteriorate and film roughness may occur on the surface of the cured product.

[(D1) component]
As an example of the component (D1) that is a material of the optical waveguide body, there is a photo radical polymerization initiator that can generate an active species (radical species) capable of polymerizing an ethylenically unsaturated group by light irradiation.
Here, light means ionizing radiation such as infrared rays, visible rays, ultraviolet rays, and X-rays, electron beams, α rays, β rays, and γ rays.
Examples of the photo radical polymerization initiator include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2 -Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthio Xanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, And bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.
Examples of commercially available radical photopolymerization initiators include Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI 1700, CGI 1750, CGI 11850, CG 24-61, Darocur 1116, 1173 (and above, Ciba Specialty Chemicals). Co., Ltd.), Lucirin TPO, TPO-L (above, manufactured by BASF), Ubekrill P36 (manufactured by UCB), and the like.
A radical photopolymerization initiator is used individually by 1 type or in combination of 2 or more types.

The content of the component (D1) in the composition for forming an optical waveguide body is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass. When the content is less than 0.1% by mass, curing does not proceed sufficiently, and a problem may occur in the transmission characteristics of the optical waveguide. On the other hand, if the content exceeds 10% by mass, the photopolymerization initiator may adversely affect long-term transmission characteristics.
In this invention, a photosensitizer can be mix | blended with the above-mentioned photoinitiator. If a photosensitizer is used in combination, energy rays such as light can be absorbed more effectively.
Photosensitizers include, for example, thioxanthone, diethylthioxanthone and thioxanthone derivatives; anthraquinone, bromoanthraquinone and anthraquinone derivatives; anthracene, bromoanthracene and anthracene derivatives; perylene and perylene derivatives; xanthone, thioxanthone and thioxanthone derivatives; And ketocoumarin. What is necessary is just to select the kind of photosensitizer according to the kind of photoinitiator.

In the composition for forming the optical waveguide body, other than the above (A1) to (D1), if necessary, for example, one polymerization in the molecule within a range not impairing the characteristics of the resin composition of the present invention. A compound having a reactive reactive group or a polymer resin (for example, epoxy resin, acrylic resin, polyamide resin, polyamideimide resin, polyurethane resin, polybutadiene resin, polychloroprene resin, polyether resin, polyester resin, styrene-butadiene block copolymer) Coal, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based polymer, silicone-based polymer) and the like can be blended.
Furthermore, various additives as necessary, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants, colorants, Storage stabilizers, plasticizers, lubricants, fillers, inorganic particles, anti-aging agents, wettability improvers, antistatic agents and the like can be blended.

Here, examples of the antioxidant include Irganox 1010, 1035, 1076, 1222 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Antigene P, 3C, FR, and Sumilizer (manufactured by Sumitomo Chemical Co., Ltd.). Examples of ultraviolet absorbers include Tinuvin P, 234, 320, 326, 327, 328, 329, 213 (and above, manufactured by Ciba Specialty Chemicals), Seesorb 102, 103, 110, 501, 202, 712, and 704 (and above). , Manufactured by Sipro Kasei Co., Ltd.). Examples of the light stabilizer include Tinuvin 292, 144, 622LD (manufactured by Ciba Specialty Chemicals), Sanol LS770 (manufactured by Sankyo Co., Ltd.), Sumisorb TM-061 (manufactured by Sumitomo Chemical Co., Ltd.), and the like. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like, and commercially available products such as SH6062 and SZ6030 (above, Toray Dow Corning Silicone Co., Ltd.), KBE903, 603, 403 (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the coating surface improver include silicone additives such as dimethylsiloxane polyether, and commercially available products include DC-57, DC-190 (manufactured by Dow Corning), SH-28PA, SH-29PA, SH. -30PA, SH-190 (above, manufactured by Toray Dow Corning Silicone), KF351, KF352, KF353, KF354 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), L-700, L-7002, L-7500, FK- 024-90 (manufactured by Nihon Unicar).
In order to prepare the composition, the above-described components may be mixed and stirred according to a conventional method.

[2. Cured film of radiation curable adhesive composition]
A cured film of the radiation-curable adhesive composition (hereinafter also referred to as “adhesive layer”) is interposed between the outer surface of at least one of the lower cladding layer and the upper cladding layer and the polyimide film layer. Formed.
In the present invention, the cured film of the radiation curable adhesive composition is between the lower clad layer and the polyimide film layer and between the clad layer and the polyimide film layer from the viewpoint of enhancing the effect of suppressing deformation at high temperatures. Are preferably formed for each of the above.
The composition for radiation curable adhesives comprises (A) a bifunctional or higher polyfunctional epoxy monomer (except for those having a (meth) acryloyl group), (B) a bifunctional or higher polyfunctional oxetane monomer, ( C) A compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule, and (D) a cationic polymerization initiator.
In addition, the polyfunctional epoxy monomer more than bifunctional which is (A) component means the monomer which has 2 or more of epoxy groups in a molecule | numerator. Moreover, the bifunctional or more polyfunctional oxetane monomer which is the component (B) means a monomer having two or more oxetanyl groups in the molecule.

Examples of the polyfunctional epoxy monomer that can be used as the component (A) include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, and brominated bisphenol F diglycidyl. Ether, brominated bisphenol S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4 '-Epoxycyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate, Limethylcaprolactone-modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, and the like.
The content rate of (A) component in the composition for adhesives becomes like this. Preferably it is 10-50 mass%, More preferably, it is 20-50 mass%. If this content rate is less than 10 mass%, adhesiveness with a polyimide film may fall. When the content exceeds 50% by mass, the curing rate decreases and the mechanical strength tends to decrease.

Examples of the bifunctional or higher polyfunctional oxetane monomer that can be used as the component (B) include xylylene oxetane, bis (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis {[(3- And ethyl-3-oxetanyl) methoxy] methyl} benzene, 1,3-bis {(1-ethyl-3-oxetanyl) methoxy} benzene, and the like.
The content rate of (B) component in the composition for adhesives becomes like this. Preferably it is 10-50 mass%, More preferably, it is 20-50 mass%. When the content is less than 10% by mass, the curing rate tends to decrease and the mechanical strength tends to decrease. When this content rate exceeds 50 mass%, the adhesive strength with an optical waveguide main body may fall.
Examples of the compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule that can be used as the component (C) include 3,4-epoxycyclohexylmethyl. Examples include methacrylate, 3,4-epoxycyclohexylmethyl acrylate, glycidyl methacrylate, glycidyl acrylate, and the like.
The content rate of (C) component in the composition for adhesive agents becomes like this. Preferably it is 1-45 mass%, More preferably, it is 5-40 mass%. When the content is less than 1% by mass, the adhesive strength with the optical waveguide main body tends to decrease. When this content rate exceeds 45 mass%, a cure rate may fall and mechanical strength may fall.

The cationic photopolymerization initiator that can be used as the component (D) releases a substance that initiates the cationic polymerization of the components (A) to (C) by receiving energy rays such as light. It is a compound that can be. Here, energy rays such as light means visible light, ultraviolet light, infrared light, X-rays, α rays, β rays, γ rays, and the like. Particularly preferable examples of the compound (D) include onium salts having a structure represented by the following general formula (6).
_{^{[R 2 a R 3 b R}} 4 c R 5 d W] + m [MX n + m] -m (6)
(Wherein the cation is an onium ion, W is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl or ^{-N = N, R 2, R} 3, R 4 And R ⁵ are the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and (a + b + c + dm) is equal to the valence of W. M is a halide complex [MX _{n + m} ], which is a metal or metalloid constituting the central atom of B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is a halogen atom such as F, Cl, Br, etc., m is the net charge of the halide complex ion, and n is the valence of M.)

The onium salt represented by the general formula (6) is a compound that releases a Lewis acid by receiving light. Specific examples of the anion [MX _{n + m} ] in the general formula (6) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarsenate. (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.

Moreover, the onium salt which has an anion represented with general formula [MXn (OH) _< ^- >] can be used. Furthermore, perchlorate ion (ClO ₄ ⁻ ), trifluoromethane sulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluene sulfonate ion, trinitrobenzene sulfonate anion, trinitrotoluene sulfonate Onium salts having other anions such as anions can also be used.

  Among such onium salts, aromatic onium salts are particularly effective as the component (D). Of these, aromatic halonium salts described in JP-A-50-151996, JP-A-50-158680, JP-A-50-151997, JP-A-52-30899, JP-A-56. Group VIA aromatic onium salts described in JP-A-55420, JP-A-55-125105, etc., Group VA aromatic onium salts described in JP-A-50-158698, etc., JP-A-56-8428 Oxosulfoxonium salts described in JP-A-56-149402 and JP-A-57-192429, aromatic diazonium salts described in JP-A-49-17040, US Pat. , 139,655 specification, and the like. Moreover, an iron / allene complex, an aluminum complex / photolytic silicon compound-based initiator, and the like can also be mentioned.

Commercially available cationic photopolymerization initiators that can be suitably used as the component (D) include UVI-6950, UVI-6970, UVI-6974, UVI-6990 (manufactured by Union Carbide), Adekaoptomer SP- 150, SP-151, SP-170, SP-172 (above, manufactured by ADEKA), Irgacure 261 (above, manufactured by Ciba Specialty Chemicals), CI-2481, CI-2624, CI-2638, CI-2064 (above Manufactured by Nippon Soda Co., Ltd.), CD-1010, CD-1011, CD-1012 (above, manufactured by Sartomer), DTS-102, DTS-103, NAT-103, NDS-103, TPS-103, MDS-103, MPI-103, BBI-103 (manufactured by Midori Chemical Co., Ltd.), PCI-061T, PCI-062T, PCI-020T, PCI-022T (manufactured by Nippon Kayaku Co., Ltd.), CPI-100A, CPI-110A, K-1 (manufactured by San Apro Co., Ltd.) and the like. Among these, UVI-6970, UVI-6974, Adekaoptomer SP-170, SP-172, CD-1012, and MPI-103 can exhibit high photocuring sensitivity in the composition containing them. This is particularly preferable because it can be performed. Said cationic photoinitiator can comprise (D) component individually by 1 type or in combination of 2 or more types.
The content rate of (D) component in the composition for adhesives becomes like this. Preferably it is 0.1-10 mass%, More preferably, it is 1-8 mass%. When the content is less than 0.1% by mass, the curability of the composition is lowered. When this content rate exceeds 10 mass%, when the adhesive composition is cured by radiation, sufficient light transmittance cannot be obtained, resulting in poor curing.

（式中、Ｘは２価の基であり、ベンゼン環のどの位置に結合していてもよい。）
ここで、一般式（７）中のＸ（２価の基）は、例えば、−Ｏ−、−ＳＯ_２−、−ＣＯ−、−Ｓ−、−Ｃ（ＣＨ_３）_２−、−Ｓｉ（ＣＨ_３）_２−または−Ｓｉ（Ｐｈ）_２−であり、好ましくは、−Ｏ−、−ＳＯ_２−、より好ましくは−Ｏ−である。
成分（Ａ２）の具体的な化合物名としては、４，４’−オキシジフタル酸二無水物（オルトジフェニルフタル酸二無水物）、３，３’，４，４’−ジフェニルスルホンテトラカルボン酸二無水物、３，３’，４，４’−ベンゾフェノンテトラカルボン酸二無水物、３，３’，４，４’−ジメチルジフェニルシランテトラカルボン酸二無水物、３，３’，４，４’−テトラフェニルテトラカルボン酸二無水物、２，２−ビス（３，４−ジカルボキシフェニル）プロパン二無水物等が挙げられる。
中でも、紫外線透過性の向上の観点から、４，４’−オキシジフタル酸二無水物、３，３’，４，４’−ジフェニルスルホンテトラカルボン酸二無水物等が、好ましく用いられ、４，４’−オキシジフタル酸二無水物が特に好ましく用いられる。 [3. Polyimide film layer]
The polyimide film layer is made of a polyimide film.
A polyimide film consists of a polymer containing an aromatic polyimide and / or an aromatic polyamic acid.
Preferable examples of the aromatic polyimide and / or aromatic polyamic acid include those obtained by reacting the following component (A2) and component (B2).
[Component (A2)]
The component (A2) is an aromatic tetracarboxylic dianhydride represented by the following general formula (7).

(In the formula, X is a divalent group and may be bonded to any position of the benzene ring.)
Here, X (divalent group) in the general formula (7) is, for example, —O—, —SO ₂ —, —CO—, —S—, —C (CH ₃ ) ₂ —, —Si ( CH ₃ ) ₂ — or —Si (Ph) ₂ —, preferably —O—, —SO ₂ —, more preferably —O—.
Specific compound names of component (A2) include 4,4′-oxydiphthalic dianhydride (orthodiphenylphthalic dianhydride), 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′- Examples thereof include tetraphenyltetracarboxylic dianhydride and 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride.
Among these, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, and the like are preferably used from the viewpoint of improving ultraviolet transmittance. '-Oxydiphthalic dianhydride is particularly preferably used.

[Component (B2)]
Component (B2) is an aromatic diamine.
Examples of the aromatic diamine used as the component (B2) include p-phenylenediamine, m-phenylenediamine, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4. '-Diaminobiphenyl, 1,5-diaminonaphthalene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 4,4'-(p-phenyleneisopropylidene) bisaniline, 4,4 '-(m -Phenylene isopropylidene) bisaniline, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3- Trimethylindane, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-diaminodiphenylmethane, 4,4'- Diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3 '-Diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4- Aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4 ′ -(P-biphenylenedioxy) dianiline etc. are mentioned.
Among these, 1,4-bis (4-aminophenoxy) benzene and 4,4 ′-(p-biphenylenedioxy) dianiline are preferably used from the viewpoint of improving ultraviolet transmittance, and 4,4 ′-(p -Biphenylenedioxy) dianiline is particularly preferably used.

The aromatic polyimide and / or aromatic polyamic acid for forming the polyimide film is produced by reacting the component (A2) and the component (B2).
Component (A2) represented by the following formula (8) (4,4′-oxydiphthalic dianhydride) and component (B2) represented by the following formula (9) (4,4 ′-(p- The reaction mechanism will be described by taking an example of producing an aromatic polyimide by reacting biphenylenedioxy) dianiline).

First, as shown in the following formulas (10) and (11), the acid anhydride group of the component (A2) (see the chemical formula on the left side of the formula (10)) and the amino group of the component (B2) (formula ( 10) on the right side) reacts to produce an aromatic polyamic acid (see formula (11)).

In the present invention, the formation of the aromatic polyamic acid by the reaction of the component (A2) and the component (B2) is carried out at a temperature of -20 to 150 ° C., preferably 0 to 100 ° C. in an organic solvent. (B2) is performed by mixing and stirring.
The proportion of component (A2) and component (B2) is preferably such that the acid anhydride group of component (A2) is 0.8 to 1.2 equivalents relative to 1 equivalent of amino group of component (B2). The ratio which becomes 1.0-1.1 equivalent is more preferable. When the amount of the acid anhydride group of the component (A2) is less than 0.8 equivalent or more than 1.2 equivalent with respect to 1 equivalent of the amino group of the component (B2), the film is applied to the substrate and dried. May not be formed.
Examples of the organic solvent used in the present invention include, for example, N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea , Aprotic polar solvents such as hexamethyl phosphortriamide; methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, ethyl lactate And esters such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; phenols such as phenol, m-cresol, xylenol, and halogenated phenol. .
Among these, N-methylpyrrolidone (NMP) is preferably used from the viewpoint of solubility.

The amount of the organic solvent used is such that the mass ratio of the total amount of the component (A2) and the component (B2) in the total amount of the reaction solution containing the component (A2), the component (B2), and the organic solvent is 0.1 to 30. The amount is 1% by mass, preferably 1-20% by mass, more preferably 1-15% by mass.
The pressure at the time of reaction is not specifically limited, Usually, a normal pressure may be sufficient. The reaction time is usually 1 to 10 hours.

When the aromatic polyamic acid represented by the formula (11) is heated in a film state formed by applying it to a substrate and drying it, the imidization proceeds to become an aromatic polyimide represented by the formula (12).

The heating temperature during imidization is 200 ° C to 400 ° C, preferably 250 ° C to 350 ° C. By heating within the temperature range, imidization of the aromatic polyamic acid can be sufficiently advanced. The heating time is preferably 30 to 120 minutes.
The imidation ratio of the aromatic polyamic acid is not particularly limited to 0 to 100%, but is preferably 50 to 100%, more preferably 80 to 100%. If the proportion is less than 50%, the water resistance of the film may be lowered.
The number average molecular weight of the aromatic polyimide and aromatic polyamic acid is preferably 3,000 or more from the viewpoint of mechanical strength as a polystyrene equivalent value measured by the GPC method.
The upper limit of the number average molecular weight of the aromatic polyimide and aromatic polyamic acid is not particularly limited, but is usually 500,000 or less.
The polyimide film is preferably subjected to corona discharge treatment on the surface.
The thickness of the polyimide film layer is preferably 1 to 60 μm, more preferably 10 to 40 μm, from the viewpoint of imparting sufficient flame retardancy and obtaining high light transmittance.

An example of the film-like optical waveguide of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view schematically showing an example of the film-like optical waveguide of the present invention. In FIG. 1, a film-shaped optical waveguide 1 is formed by curing a radiation-curable adhesive composition on each of the upper and lower surfaces of an optical waveguide body composed of a lower cladding layer 2, a core portion 3, and an upper cladding layer 4. Polyimide film layers 7 and 8 are provided through the films 5 and 6.
An example of the manufacturing method of the film-form optical waveguide 1 is as follows. First, the radiation curable adhesive composition is applied to the treated surface of the polyimide film 7 whose surface has been subjected to corona discharge treatment so as to have a certain thickness (for example, 5 μm). Next, the composition layer is irradiated with ultraviolet rays and photocured to form a cured film 5. The lower clad layer forming composition is applied to the upper surface of the cured film 5 so as to have a certain thickness (for example, 10 μm), and the composition layer is irradiated with ultraviolet rays to be photocured, The clad layer 2 is formed. Similarly, the core portion 3 and the upper clad layer 4 are sequentially formed on the lower clad layer 2 to obtain a laminate composed of an optical waveguide body and the like. Thereafter, the radiation curable adhesive composition is applied to the treated surface of the polyimide film 8 whose surface has been subjected to corona discharge treatment so as to have a certain thickness (for example, 5 μm). Next, on this composition layer, a laminate composed of the optical waveguide main body or the like is placed, irradiated with ultraviolet rays from below, the composition layer is photocured, and a cured film 6 is formed. A film-like optical waveguide is completed.

[1. Preparation of composition for clad layer]
[Production of component (A1)]
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 1.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 115 g of propylene glycol monomethyl ether acetate as an organic solvent were charged. The mixture was stirred until the polymerization initiator was dissolved. Subsequently, 20 g of hydroxyethyl methacrylate, 25 g of dicyclopentanyl methacrylate, 40 g of methyl methacrylate, and 15 g of n-butyl acrylate were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 70 ° C., and polymerization was carried out at this temperature for 6 hours. Thereafter, 0.12 g of di-n-butyltin dilaurate and 0.05 g of 2,6-di-t-butyl-p-cresol were charged into the obtained solution, and 23.7 g of 2-methacryloxyethyl isocyanate was stirred. Was added dropwise so that the temperature was kept at 60 ° C. or lower. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 5 hours to obtain a polymer solution having a methacryl group in the side chain. Thereafter, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, it was redissolved in tetrahydrofuran having the same mass as the coagulated product and coagulated again with a large amount of hexane. After performing this re-dissolution-coagulation operation three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain the desired copolymer A-1. In addition, Table 1 shows compound names and blending amounts of the monomers used.

[Production of component (B1)]
In a reaction vessel equipped with a stirrer, 13.6 parts by mass of isophorone diisocyanate, 81.7 parts by mass of polypropylene glycol having a number average molecular weight of 2,000, 0.01 parts by mass of 2,6-di-t-butyl-p-cresol Was cooled to 5 to 10 ° C. While stirring, 0.05 parts by mass of di-n-butyltin dilaurate was added and the mixture was stirred for 2 hours while adjusting the temperature to be kept at 30 ° C. or lower, and then the temperature was raised to 50 ° C. and further stirred for 2 hours. . Subsequently, 4.7 parts by mass of 2-hydroxyethyl acrylate (the total amount of 100 parts by mass above) was dropped, and after completion of the dropping, the mixture was reacted at 50 to 70 ° C. for 1 hour. The reaction was terminated when the residual isocyanate was 0.1% by mass or less, and Compound B-1 was obtained.
[Preparation of radiation curable composition for clad layer]
The components shown in Table 2 were mixed to obtain a cladding layer composition J-1.

[Examples 1 to 3, Comparative Example 1]
As shown in Table 3, components (A) to (D) were mixed to obtain adhesive compositions (Examples 1 to 3, Comparative Example 1). The following tests were conducted using these adhesive compositions.
As the polyimide film, “Kapton 100H” (trade name, manufactured by Toray DuPont, thickness: 25 μm) was used.

The details of the components in Table 3 are as follows.
(A) Component: 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate (manufactured by ADEKA, trade name: KRM2110)
(B) component: Xylylene oxetane (product name: XDO, manufactured by Toagosei Co., Ltd.)
Component (C): 3,4-epoxycyclohexylmethyl methacrylate (Daicel Chemical Industries, trade name: Cycler M100)
(D) component: "SP-172 (brand name)" (made by ADEKA)

[Heat-resistant]
The film-like optical waveguide obtained by bonding the optical waveguide body and the polyimide film using the adhesive composition of Examples 1 to 3 is a film obtained using the adhesive composition of Comparative Example 1. Compared with the optical waveguide, thermal deformation under an environment of 85 ° C. could be greatly suppressed.
[Adhesion between adhesive layer and cladding layer]
After applying a composition for an adhesive on a polyimide film subjected to corona discharge treatment so as to have a thickness of 20 μm, an illuminance of 20 mW / cm ² and an irradiation light amount of 1.5 J / cm ² are used using an aligner manufactured by Disco Corporation. The adhesive layer was photocured under conditions. Thereafter, the prepared clad layer composition is applied to the upper surface of the cured adhesive layer so as to have a thickness of 70 μm, dried at 120 ° C. for 5 minutes, and then used with an DISCO aligner. The clad layer composition layer was photocured under the conditions of an illuminance of 20 mW / cm ² and an irradiation light amount of 1.5 J / cm ² to obtain a laminated film.
Work to peel the clad layer of the resulting laminated film by hand. As a result, if it could not be peeled, "○" and if it could be peeled "x", the adhesiveness between the adhesive layer and the clad layer Evaluated. The results are shown in Table 3.
[Adhesion between adhesive layer and polyimide film layer]
A laminated film was obtained in the same manner as in the above “adhesiveness between the adhesive layer and the clad layer”.
In an environment of 23 ° C. and 50% relative humidity, a 180 ° peel test was performed on the laminated film at a speed of 50 mm / min using an Instron tensile tester. The case of 200 N / m or more was evaluated as “◯”, and the case of less than 200 N / m was evaluated as “x”, and the adhesion between the adhesive layer and the polyimide film layer was evaluated. The results are shown in Table 3.

It is sectional drawing which shows typically an example of the film-form optical waveguide of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film-form optical waveguide 2 Lower clad layer 3 Core part 4 Upper clad layer 5,6 Adhesive layer (hardened film of the composition for photocurable adhesives)
7,8 Polyimide film layer

Claims (4)

A film-shaped optical waveguide comprising a lower clad layer, a core portion, and an upper clad layer, wherein at least one outer surface of the lower clad layer and the upper clad layer has radiation curing comprising the following components (A) to (D): A film-like optical waveguide comprising a polyimide film layer through a cured film of a composition for adhesive.
(A) Bifunctional or higher polyfunctional epoxy monomer (excluding those having a (meth) acryloyl group)
(B) Bifunctional or higher polyfunctional oxetane monomer (C) Compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule (D) Cationic photopolymerization initiator   The film-like light according to claim 1, wherein each of the lower clad layer and the upper clad layer is obtained by curing a radiation curable composition containing a monomer having a (meth) acryloyl group and a radical polymerizable initiator. Waveguide. The film-shaped optical waveguide according to claim 1 or 2, wherein the content of the components (A) to (D) with respect to the total amount of the radiation-curable adhesive composition is as follows.
(A) Bifunctional or higher polyfunctional epoxy monomer (excluding those having a (meth) acryloyl group) 10 to 50% by mass
(B) Bifunctional or higher polyfunctional oxetane monomer 10 to 50% by mass
(C) 1 to 45% by mass of a compound having at least one (meth) acryloyl group and at least one epoxy group in one molecule;
(D) Cationic photopolymerization initiator 0.1 to 10% by mass.   The said polyimide film layer is a film-form optical waveguide of any one of Claims 1-3 which consists of a polyimide film by which the surface was corona-discharge-treated.

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