JP2009244357A - Film-like optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-like optical waveguide having excellent flame retardancy and to provide a photosensitive resin composition for forming the film-like optical waveguide. <P>SOLUTION: The film-like optical waveguide includes a lower clad layer 12, a core part 20, and an upper clad layer 22. The clad layers 12, 22 includes (A) a compound having at least one fluorine atom and at least one polymerization carbon-carbon double coupling (however, excluding what containing phosphorous atoms) in a molecule, (B) a compound having at least one phosphorous atom and at least one polymerization carbon-carbon double coupling in a molecule (however, excluding containing fluorine atoms), and (C) a cured material of the photosensitive resin composition including an optical radical polymerization initiator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a film-shaped optical waveguide having flame retardancy and a photosensitive resin composition for use as a material for the 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.
In recent years, photo-curable compositions such as (meth) acrylic and epoxy-based resins have been used to improve productivity, such as shortening the manufacturing time and increasing yield, in place of the conventional quartz-based optical waveguides. A polymer-based optical waveguide using a photocurable composition of the above has been proposed.
Examples of the (meth) acrylic photocurable composition include (A) a vinyl polymer having a carboxyl group, a polymerizable group, and other organic groups, and (B) two or more polymerizable molecules in the molecule. A radiation curable composition for forming an optical waveguide containing a compound having a reactive group and (C) a radiation polymerization initiator has been proposed (Patent Document 1).
Moreover, as an epoxy-type photocurable composition, the photosensitive resin composition for optical waveguide formation containing (A) specific novolak-type epoxy resin and (B) photo-acid generator is proposed, for example. (Patent Document 2).
JP 2003-195079 A JP 2005-274664 A

A conventional photocurable composition used as a material for forming an optical waveguide has transmission characteristics suitable for use as an optical signal transmission medium, but has a problem of poor flame retardancy.
On the other hand, by providing a protective layer on the outer surface of the optical waveguide, properties such as flame retardancy are imparted, but without providing the protective layer, the optical waveguide body (core portion or cladding layer) is provided. If these characteristics can be imparted, further simplification of the manufacturing process, reduction in cost, and the like can be achieved.
Accordingly, the present invention provides a photosensitive resin composition that can be used as a material for an optical waveguide body (core portion or cladding layer) to form a film-like optical waveguide having excellent flame retardancy, and the film-like light. An object is to provide a waveguide.

  As a result of intensive studies to solve the above problems, the present inventor has found that a photosensitive resin composition containing a fluorine-containing ethylenically unsaturated compound, a phosphorus-containing ethylenically unsaturated compound, and a radical photopolymerization initiator is used. Thus, the inventors have found that the above object of the present invention can be achieved and completed the present invention.

That is, the present invention provides the following [1] to [7].
[1] An optical waveguide having a core portion and a clad layer, wherein at least one of the core portion and the clad layer includes the following components (A) to (C): A film-like optical waveguide comprising a material.
(A) A compound having in the molecule at least one fluorine atom and at least one polymerizable carbon-carbon double bond (excluding those containing a phosphorus atom).
(B) A compound having at least one phosphorus atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a fluorine atom).
(C) Photoradical polymerization initiator [2] A film-shaped optical waveguide comprising a lower cladding layer, a core portion, and an upper cladding layer, wherein the lower cladding layer and the upper cladding layer are the photosensitive resin for an optical waveguide. The film-like optical waveguide according to the above [1], comprising a cured product of the composition.
[3] In the photosensitive resin composition for an optical waveguide, the blending ratio of each of the component (A), the component (B), and the component (C) is the total amount of the photosensitive resin composition (however, organic When the solvent is included, the total amount excluding the organic solvent) is 100% by mass, and the above [1] or [2] is 5 to 80% by mass, 5 to 80% by mass, and 0.1 to 10% by mass. The film-form optical waveguide as described.
[4] Any one of the above [1] to [3], wherein the photosensitive resin composition for an optical waveguide further includes (D) a radical polymerizable compound other than the component (A) and the component (B). The film-like optical waveguide according to 1.
[5] The film-shaped optical waveguide according to any one of [1] to [4], wherein the photosensitive resin composition for an optical waveguide further includes (E) a polyimide silicone resin.
[6] The film-shaped optical waveguide according to any one of [1] to [5], wherein the photosensitive resin composition for an optical waveguide further includes (F) an organic solvent.
[7] (A) Compound having at least one fluorine atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a phosphorus atom), (B) A compound having at least one phosphorus atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a fluorine atom), and (C) a photoradical polymerization initiator. And a photosensitive resin composition for an optical waveguide.

The film-shaped optical waveguide of the present invention has excellent flame retardancy because at least one of the core portion and the clad layer is made of a cured product of a photosensitive resin composition containing a specific component. In particular, when the lower cladding layer and the upper cladding layer of the lower cladding layer, the core portion, and the upper cladding layer are made of a cured product of the photosensitive resin composition, particularly excellent flame retardancy can be obtained. .
In the film-shaped optical waveguide of the present invention, the optical waveguide main body (core portion or cladding layer) itself has excellent flame retardancy, and for example, it is not necessary to provide a protective layer on the outer surface of the cladding layer. In addition, simplification of the manufacturing process and reduction in cost can be achieved.

［式（１）中、Ｒ^１はフッ素原子、フルオロアルキル基又は−ＯＲ^２で表される基（Ｒ^２はアルキル基又はフルオロアルキル基を示す。）を示す。］

［式（２−１）中、Ｒ^３は水素原子又はメチル基を、Ｒ^４はアルキル基、−（ＣＨ_２）_ｄ−ＯＲ^５若しくは−ＯＣＯＲ^５で表される基（Ｒ^５はアルキル基又はグリシジル基を、ｄは０又は１の数を示す。）、カルボキシル基又はアルコキシカルボニル基を示す。］

［式（２−２）中、Ｒ^３は式（２−１）で定義した通りであり、Ｒ^６はフルオロアルキル基又はフルオロアリール基を示し、ｘは０〜２の数を示す。］

［式（３）中、Ｒ^７は水素原子又はメチル基を、Ｒ^８は水素原子又はヒドロキシアルキル基を、ｖは０又は１の数を示す。］ The film-like optical waveguide of the present invention comprises a core part and a clad layer, and at least one of the core part and the clad layer is made of a cured product of a photosensitive resin composition for an optical waveguide containing a specific component.
First, the photosensitive resin composition for optical waveguides of the present invention will be described in detail.
[Photosensitive resin composition for optical waveguide]
The photosensitive resin composition for optical waveguides includes (A) to (C) components and other optional components that are blended as necessary.
[(A) component]
The component (A) used in the photosensitive resin composition for an optical waveguide is a compound having at least one fluorine atom and at least one polymerizable carbon-carbon double bond in the molecule (however, a phosphorus atom Is excluded.) By using the component (A) together with the component (B) described later, a film-like optical waveguide having excellent flame retardancy can be obtained.
Examples of the component (A) include compounds having at least one fluorine atom and at least one ethylenically unsaturated group. Here, as the ethylenically unsaturated group, a (meth) acryloyl group is preferable.
Specific examples of the component (A) include a structural unit represented by the following formula (1), a structural unit represented by the following formula (2-1) and / or formula (2-2), and the following formula ( Compound (A-1) obtained by reacting a hydroxyl group-containing fluoropolymer (a) containing the structural unit represented by 3) with an ethylenically unsaturated group-containing compound (b) capable of reacting with a hydroxyl group Is mentioned.

[In the formula (1), R ¹ represents a fluorine atom, a fluoroalkyl group or a group represented by —OR ² (R ² represents an alkyl group or a fluoroalkyl group). ]

[In Formula (2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkyl group, and a group represented by — (CH ₂ ) _d —OR ⁵ or —OCOR ⁵ (R ⁵ represents an alkyl group or A glycidyl group, d represents a number of 0 or 1, and a carboxyl group or an alkoxycarbonyl group; ]

[In formula (2-2), R ³ is as defined in formula (2-1), R ⁶ represents a fluoroalkyl group or a fluoroaryl group, and x represents a number of 0-2. ]

[In Formula (3), R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents a hydrogen atom or a hydroxyalkyl group, and v represents a number of 0 or 1. ]

In the above formula (1), examples of the fluoroalkyl group of R ¹ and R ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorocyclohexyl group. A C1-C6 fluoroalkyl group is mentioned. The alkyl group R ^2, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an alkyl group having 1 to 6 carbon atoms such as a cyclohexyl group.
The structural unit represented by the formula (1) (hereinafter also referred to as the structural unit (1)) can be introduced by using a fluorine-containing vinyl monomer as a polymerization component.
The fluorine-containing vinyl monomer is not particularly limited as long as it is a compound having at least one polymerizable unsaturated double bond and at least one fluorine atom. Specifically, fluoroolefins such as tetrafluoroethylene, hexafluoropropylene, and 3,3,3-trifluoropropylene; alkyl perfluorovinyl ethers or alkoxyalkyl perfluorovinyl ethers; perfluoro (methyl vinyl ether), perfluoro ( Perfluoro (alkyl vinyl ethers) such as ethyl vinyl ether), perfluoro (propyl vinyl ether), perfluoro (butyl vinyl ether), perfluoro (isobutyl vinyl ether); perfluoro (alkoxyalkyl vinyl ether) such as perfluoro (propoxypropyl vinyl ether) And the like. These are used individually by 1 type or in combination of 2 or more types.
Among these, hexafluoropropylene, perfluoro (alkyl vinyl ether), and perfluoro (alkoxyalkyl vinyl ether) are preferable, and hexafluoropropylene and perfluoro (alkyl vinyl ether) or perfluoro (alkoxyalkyl vinyl ether) are used in combination. Is more preferable. By using such a combination, it is possible to obtain a film-like optical waveguide having more excellent flame retardancy.

In formula (2-1), examples of the alkyl group represented by R ⁴ or R ⁵ include alkyl groups having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a hexyl group, a cyclohexyl group, and a lauryl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.
The structural unit represented by the formula (2-1) (hereinafter also referred to as the structural unit (2-1)) uses a vinyl monomer having a substituent corresponding to the formula (2-1) as a polymerization component. Can be introduced.
Examples of such vinyl monomers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl. Alkyl ethers or cycloalkyl vinyl ethers such as vinyl ether, n-dodecyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether; allyl ethers such as ethyl allyl ether, butyl allyl ether; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate , Vinyl carboxylates such as vinyl caproate, vinyl versatate, vinyl stearate Class: methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n -(Meth) acrylic acid esters such as propoxy) ethyl (meth) acrylate; unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid; and the like. These are used individually by 1 type or in combination of 2 or more types.

［式中、Ｒ^３は水素原子又はメチル基であり、ｘは０〜２の数を表す。また、上記式中、芳香環の中にＦと記した基は、５つの水素原子の全てがフッ素原子で置換されていることを示す。］ The structural unit represented by the formula (2-2) (hereinafter also referred to as the structural unit (2-2)) uses a vinyl monomer having a substituent corresponding to the formula (2-2) as a polymerization component. Can be introduced.
Examples of such vinyl monomers include those having the following structural formula.

[Wherein R ³ represents a hydrogen atom or a methyl group, and x represents a number of 0 to 2. In the above formula, a group denoted by F in the aromatic ring indicates that all five hydrogen atoms are substituted with fluorine atoms. ]

In formula (3), as the hydroxyalkyl group of R ⁸ , 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 5-hydroxypentyl group , 6-hydroxyhexyl group.
The structural unit represented by the formula (3) (hereinafter also referred to as the structural unit (3)) can be introduced by using a hydroxyl group-containing vinyl monomer as a polymerization component.
Examples of such a hydroxyl group-containing vinyl monomer include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxypentyl vinyl ether, Examples include hydroxyl group-containing vinyl ethers such as hydroxyhexyl vinyl ether, hydroxyl group-containing allyl ethers such as 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether, and glycerol monoallyl ether, allyl alcohol, and the like.
Moreover, as a hydroxyl-containing vinyl monomer, in addition to the above, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, caprolactone (meth) acrylate, polypropylene Glycol (meth) acrylate or the like can be used.

In addition, in 100 mol% in total of the structural unit (1), the structural unit (2-1) and / or the structural unit (2-2), and the structural unit (3), the content of each structural unit is as follows: It is as follows.
The content of the structural unit (1) is preferably 30 to 65 mol%, more preferably 35 to 60 mol%, still more preferably 40 to 55 mol%. When the content is less than 30 mol%, it may be difficult to impart flame retardancy. On the other hand, when it exceeds 65 mol%, the solubility of the hydroxyl group-containing fluoropolymer in an organic solvent decreases. In addition, the transparency of the resulting cured product and the adhesion to the substrate may be reduced.
The content of the structural unit (2-1) and / or the structural unit (2-2) is preferably 1 to 50 mol%, more preferably 1 to 45 mol%. When the content is less than 1 mol%, the solubility of the hydroxyl group-containing fluorine-containing copolymer in an organic solvent may be lowered. On the other hand, when the content exceeds 50 mol%, the transparency of the obtained cured product may be reduced. And optical characteristics may be deteriorated.
The content of the structural unit (2-1) and / or the structural unit (2-2) is the structural unit when the structural unit (2-1) or (2-2) is used alone. It means the content of either (2-1) or (2-2), and when the structural units (2-1) and (2-2) are used together, it means the total content of both. .
The content of the structural unit (3) is preferably 5 to 60 mol%, more preferably 5 to 55 mol%, and still more preferably 10 to 50 mol%. When the content is less than 5 mol%, the hardness of the cured product may be insufficient. On the other hand, when it exceeds 60 mol%, the transparency and optical properties of the cured product may be deteriorated.

In addition, the hydroxyl group-containing fluoropolymer (a) can also contain structural units other than the above (1) to (3).
The polystyrene-reduced number average molecular weight of the hydroxyl group-containing fluoropolymer (a) measured by gel permeation chromatography using tetrahydrofuran as a solvent is preferably 5,000 to 500,000, more preferably 10,000 to 300. 1,000, more preferably 10,000 to 100,000. When the number average molecular weight is less than 5,000, the mechanical strength of the cured product may be lowered. On the other hand, when the number average molecular weight is more than 500,000, the viscosity of the photosensitive resin composition is increased and the coating property is lowered. There are things to do.

(B) Examples of the ethylenically unsaturated group-containing compound capable of reacting with a hydroxyl group include compounds having a functional group capable of reacting with a hydroxyl group in the hydroxyl group-containing fluoropolymer (a) and an ethylenically unsaturated group. It is done.
Examples of the functional group include an isocyanate group, an acid chloride group, and a carboxylic acid group, and an isocyanate group is preferable.
As the ethylenically unsaturated group, a (meth) acryloyl group is preferable.
Specific examples of such compounds include (meth) acrylic acid, (meth) acryloyl chloride, anhydrous (meth) acrylic acid, 2- (meth) acryloyloxyethyl isocyanate, 2- (meth) acryloyloxypropyl isocyanate, 1 , 1- (bisacryloyloxymethyl) ethyl isocyanate and the like. These are used individually by 1 type or in combination of 2 or more types.

Compound (A-1) is a vinyl monomer for introducing each of the structural unit (1), structural unit (2-1) and / or structural unit (2-2), and structural unit (3). Then, after polymerizing by a known method to obtain a hydroxyl group-containing fluorine-containing polymer (a), the component (b) (functional group capable of reacting with a hydroxyl group and ethylene) is added to the hydroxyl group in the polymer (a). The compound can be synthesized by reacting a functional group in the compound having a polymerizable unsaturated group.
The component (b) is preferably blended so that the functional group in the component (b) and the hydroxyl group in the structural unit (3) (or the hydroxyl group-containing vinyl monomer) react in an equivalent amount. . Specifically, the ratio of the number of functional groups in component (b) to the number of hydroxyl groups (number of functional groups in component (b) / number of hydroxyl groups) is 0.8 to 1.2, preferably It mix | blends in the quantity used as 0.9-1.1.

［式（４）中、Ｒ^９は水素原子又はメチル基である。］ Another example of the component (A) is a compound (A-2) represented by the following formula (4).

[In Formula (4), R ⁹ is a hydrogen atom or a methyl group. ]

In formula (4), R ⁹ is preferably a hydrogen atom.
As a commercial product of such a compound, LINC-3A (manufactured by Kyoeisha Chemical Co., Ltd .; the compound represented by the above formula (4) (wherein R ⁹ is a hydrogen atom) is 65% by weight. And those containing pentaerythritol tetraacrylate at a content of 35% by weight).

In the photosensitive resin composition for an optical waveguide, the blending ratio of the component (A) is preferably 100% by mass based on the total amount of the photosensitive resin composition (however, when including the organic solvent, the total amount excluding the organic solvent). Is 5 to 80% by mass, more preferably 6 to 70% by mass. When the blending ratio is less than 5% by mass, the flame retardancy of the film-shaped optical waveguide is lowered, which is not preferable. On the other hand, if the blending ratio exceeds 80% by mass, the ratio of the other components (particularly the component (B)) decreases accordingly, and the flame retardancy of the film-shaped optical waveguide is lowered, which is not preferable.
In addition, as a component (A), the said compound (A-1) or compound (A-2) may be used independently, or these can also be used together, for example.

（式（５）中、Ｒ^１０、Ｒ^１１、及びＲ^１２は、各々独立して、水素原子、炭素数１〜１０のアルキル基、炭素数３〜２０の脂環族基、炭素数６〜１０の１価のアリール基、炭素数７〜１１のアラルキル基、又は（メタ）アクリロイル基を有する１価の有機基であり、Ｒ^１０、Ｒ^１１、及びＲ^１２のうち少なくとも１つは、（メタ）アクリロイル基を有する１価の有機基である。） [Component (B)]
The component (B) used in the photosensitive resin composition for an optical waveguide is a compound having at least one phosphorus atom and at least one polymerizable carbon-carbon double bond in the molecule (however, a fluorine atom) Is excluded.) By using the component (B) together with the component (A) described above, a film-shaped optical waveguide having excellent flame retardancy can be obtained.
As the component (B), a compound having one phosphorus atom and having at least one (meth) acryloyl group is preferable. Such a compound has, for example, a structure represented by the following formula (5).

(In the formula ^{(5), R 10, R} 11, and ^{R 12} are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, alicyclic group having 3 to 20 carbon atoms, 6 carbon atoms 10 is a monovalent organic group having a monovalent aryl group having 10 to 11 carbon atoms, an aralkyl group having 7 to 11 carbon atoms, or a (meth) acryloyl group, and at least one of R ¹⁰ , R ¹¹ , and R ¹² is ( A monovalent organic group having a (meth) acryloyl group.)

In formula (5), examples of the alkyl group having 1 to 10 carbon atoms of R ¹⁰ , R ¹¹ and R ¹² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, i -Butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl Groups and the like.
Examples of the alicyclic group having 3 to 20 carbon atoms include a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 2-methylcyclohexyl group, a 3-methylcyclohexyl group, a 4-methylcyclohexyl group, a 4-chlorocyclohexyl group, 4-t-butylcyclohexyl group, norbornyl group, isobornyl group, adamantyl group, 2-methyladamantyl group, tricyclodecanyl group and the like can be mentioned.

Examples of the monovalent aryl group having 6 to 10 carbon atoms include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a xylyl group, a cumenyl group, and a 1-naphthyl group.
Examples of the aralkyl group having 7 to 11 carbon atoms include a benzyl group, an α-methylbenzyl group, a phenethyl group, and a naphthylmethyl group.

（式（６）中、Ｒ^１３は、水素原子又はメチル基であり、ｎは１以上の整数である。）
一般式（６）中、ｎは１以上の整数であり、好ましくは１〜１０の整数である。 Examples of the monovalent organic group having a (meth) acryloyl group include a group represented by the following general formula (6).

(In formula (6), R ¹³ is a hydrogen atom or a methyl group, and n is an integer of 1 or more.)
In general formula (6), n is an integer greater than or equal to 1, Preferably it is an integer of 1-10.

Specific examples of such component (B) include, for example, mono [2- (meth) acryloyloxyethyl] phosphate, mono [2- (meth) acryloyloxyethyl] diphenyl phosphate, and mono [2- (meth) acryloyl. Examples include oxypropyl] phosphate, bis [2- (meth) acryloyloxyethyl] phosphate, bis [2- (meth) acryloyloxypropyl] phosphate, tris [2- (meth) acryloyloxyethyl] phosphate, and the like. Of these, tris [2- (meth) acryloyloxyethyl] phosphate is preferable.
(B) As a commercial item of the phosphoric acid ester compound used as a component, for example, Biscoat 3PA (made by Osaka Organic Chemical Industry Co., Ltd.), light ester P-1M, light ester P-2M (made by Kyoeisha Chemical Co., Ltd.), MR- 200, MR-260 (manufactured by Daihachi Chemical Co., Ltd.) and the like.

  In the photosensitive resin composition for an optical waveguide, the blending ratio of the component (B) is preferably set so that the total amount of the photosensitive resin composition (however, when the organic solvent is included, the total amount excluding the organic solvent) is 100% by mass. Is from 5 to 80 mass%, more preferably from 5 to 50 mass%, still more preferably from 10 to 40 mass%. When the blending ratio is less than 5% by mass, the flame retardancy of the film-shaped optical waveguide is lowered, which is not preferable. On the other hand, if the blending ratio exceeds 80% by mass, the blending ratio of other components (particularly the component (A)) is decreased, and the flame retardancy of the film-shaped optical waveguide is decreased.

[Component (C)]
(C) component used for the photosensitive resin composition for optical waveguides is a radical photoinitiator. The radical photopolymerization initiator is a photopolymerization initiator that can generate an active species (radical) by light. 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 radical photopolymerization 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, die Ruthioxanthone, 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. Among these, 1-hydroxycyclohexyl phenyl ketone and the like are preferably used from the viewpoints of polymerization rate and solution stability.
Examples of the commercially available component (C) include Irgacure 184, 369, 379, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1116, 1173 (and above). Ciba Specialty Chemicals); Lucirin TPO, LR8883, LR8970 (above, manufactured by BASF); Ubekrill P36 (manufactured by UCB), and the like.
A radical photoinitiator is used individually by 1 type or in combination of 2 or more types.

  Moreover, a photosensitizer can be used with a radical photoinitiator. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Isoamyl etc. are mentioned. Examples of commercially available photosensitizers include Ubekryl P102, 103, 104, and 105 (above, manufactured by UCB).

  In the photosensitive resin composition for an optical waveguide, the blending ratio of the component (C) is preferably 100% by mass based on the total amount of the photosensitive resin composition (however, when including the organic solvent, the total amount excluding the organic solvent). Is 0.1 to 10% by mass, more preferably 0.2 to 7% by mass, and still more preferably 0.5 to 5% by mass. If the blending ratio is less than 0.1% by mass, the photocurability of the composition is lowered, and a film-like optical waveguide having sufficient mechanical strength cannot be obtained. On the other hand, if the blending ratio exceeds 10% by mass, an excessive amount of radical photopolymerization initiator may adversely affect the long-term characteristics of the film-shaped optical waveguide.

[(D) component]
The photosensitive resin composition for optical waveguides can contain a radically polymerizable compound ((D) component) other than the (A) component and the (B) component, if necessary. The radical polymerizable compound is a compound having an ethylenically unsaturated bond (C = C), specifically, a compound having a (meth) acryloyl group or a vinyl group. For example, one ethylene per molecule. And monofunctional monomers having a polymerizable unsaturated bond and polyfunctional monomers having two or more ethylenically unsaturated bonds in one molecule.
The monofunctional monomer and the polyfunctional monomer can be used singly or in combination of two or more, or at least one monofunctional monomer and at least one polyfunctional monomer can be used in combination.

（式（７）中、Ｒ^１４は水素原子又はメチル基、Ｒ^１５は炭素数２〜８のアルキレン基、ｍは１〜８の整数を表す。）

（式（８）中、Ｒ^１６及びＲ^１８は、各々独立して、水素原子又はメチル基、Ｒ^１７は炭素数２〜８のアルキレン基、ｌは１〜８の整数を表す。） Specific examples of the monofunctional monomer include, for example, vinyl monomers such as N-vinylpyrrolidone, N-vinylcaprolactam, vinylimidazole, and vinylpyridine; isobornyl (meth) acrylate, bornyl (meth) acrylate, and tricyclodecanyl (meth). Acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethyl (meth) Acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate Rate, isopropyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) ) Acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) ) Acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tetrahydrofurfuryl (meth) Acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (Meth) acrylate, methoxypolypropylene glycol (meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meta ) Acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) ) Acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, hydroxybutyl building ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, and the following general formula (7), ( And monofunctional monomers represented by 8).

(In formula (7), R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 2 to 8 carbon atoms, and m represents an integer of 1 to 8)

(In Formula (8), R ¹⁶ and R ¹⁸ each independently represent a hydrogen atom or a methyl group, R ¹⁷ represents an alkylene group having 2 to 8 carbon atoms, and l represents an integer of 1 to 8)

  As a commercial item of a monofunctional monomer, for example, Biscoat 160 (manufactured by Osaka Organic Chemical Industry Co., Ltd.); ACMO (manufactured by Kojin Co., Ltd.) and the like can be mentioned.

  Examples of the polyfunctional monomer include a bifunctional monomer and a trifunctional or higher monomer. Here, the bifunctional monomer is an unsaturated monomer having two (meth) acryloyl groups or vinyl groups in the molecule. Specific examples thereof include 1,4-butanediol diacrylate, 1 , 6-hexanediol diacrylate, alkyl diol diacrylate such as 1,9-nonanediol diacrylate, polyalkylene glycol diacrylate such as ethylene glycol di (meth) acrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, Examples include neopentyl glycol di (meth) acrylate and tricyclodecane methanol diacrylate.

Examples of the trifunctional or higher functional monomer include (meth) acrylates having three or more (meth) acryloyl groups, for example, (meth) acrylates of trihydric or higher polyhydric alcohols. Specifically, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-acryloyloxyethyl) isocyanurate, pentaerythritol polyacrylate, etc. Can be mentioned.
As a commercial item of a polyfunctional monomer, TMPTA (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.

  In the photosensitive resin composition for an optical waveguide, the blending ratio of the component (D) is preferably 100% by mass based on the total amount of the photosensitive resin composition (however, when including the organic solvent, the total amount excluding the organic solvent). Is 0 to 40% by mass, more preferably 0 to 30% by mass, and still more preferably 5 to 20% by mass. By making the said mixture ratio 5 mass% or more, the photocurability of a composition can be improved more and the film-form optical waveguide excellent in mechanical strength can be obtained. On the other hand, when the above blending ratio exceeds 40% by mass, the blending ratio of other components is decreased accordingly, and the flame retardancy of the film-shaped optical waveguide may be decreased.

（式中、Ｘ^１及びＸ^２は、各々独立して、四価の有機基、Ｙは二価の有機基、Ｚはオルガノポリシロキサン基を有する二価の有機基である。） [(E) component]
The photosensitive resin composition for optical waveguides can contain a polyimide silicone resin ((E) component) as needed. Examples of the polyimide silicone resin include a polyimide silicone resin including a repeating unit represented by the following formula (9) and a repeating unit represented by the following formula (10).

(Wherein, X ¹ and X ² are each independently a tetravalent organic group, Y is a divalent organic group, and Z is a divalent organic group having an organopolysiloxane group.)

In the formulas (9) and (10), X ¹ and X ² are each independently a tetravalent organic group, such as 4,4′-oxydiphthalic dianhydride (orthodiphenylphthalic dianhydride). ), 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyl Acids such as diphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride Examples include tetravalent organic groups derived from anhydrides. Of these, tetravalent organic groups derived from 4,4′-oxydiphthalic dianhydride and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride are preferred.

  Y in the formula (9) is a divalent organic group such as 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-phenyleneisopropylidene) 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 ′ -Divalent organic groups derived from diamines such as-(p-biphenylenedioxy) dianiline It is. Of these, divalent organic groups derived from 2,2-bis [4- (4-aminophenoxy) phenyl] propane are preferred.

（式中、Ｒ^１９及びＲ^２０は、各々独立して、２価の炭化水素基又はフェニレン基であり、Ｒ^２１〜Ｒ^２４は、各々独立して、炭素数１〜５のアルキル基又はフェニル基であり、ｒは２〜３０の整数である。） Z in the formula (10) is a divalent organic group having an organopolysiloxane structure, and examples thereof include a divalent group represented by the following formula (11). The divalent group represented by the formula (11) is a divalent residue excluding the amino group of diaminoorganopolysiloxane.

(In the formula, R ¹⁹ and R ²⁰ are each independently a divalent hydrocarbon group or a phenylene group, and R ^{21 to} R ²⁴ are each independently an alkyl group having 1 to 5 carbon atoms or phenyl. And r is an integer of 2 to 30.)

In formula (11), R ¹⁹ and R ²⁰ are each independently a divalent hydrocarbon group or a phenylene group, preferably a C 1-5 divalent alkylene group.
In formula (11), R ^{22 to} R ²⁴ each independently represents an alkyl group having 1 to 5 carbon atoms or a phenyl group, preferably a methyl group.
In Formula (11), r is an integer of 2-30, Preferably it is an integer of 3-20.

  The proportion of the structural unit represented by the formula (9) and the structural unit represented by the formula (10) is preferably 10% of the structural unit represented by the formula (9) with respect to the total of 100 mol%. Mol% to 90 mol%, more preferably 20 mol% to 80 mol%, and the structural unit represented by the formula (10) is preferably 10 mol% to 90 mol%, more preferably 20 mol% to 80 mol%. Mol%.

The polyimide silicone resin containing the structural unit represented by the formula (9) and the structural unit represented by the formula (10) is, for example, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4. By reacting an acid dianhydride such as' -diphenylsulfonetetracarboxylic dianhydride, a diamine such as 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and a diaminoorganopolysiloxane Obtainable.
The weight average molecular weight of the polyimide silicone resin is preferably 5,000 to 100,000, more preferably 10,000 to 70,000.

  (E) SMP2006 (made by Shin-Etsu Chemical Co., Ltd.) etc. are mentioned as a commercial item of the polyimide silicone resin used as a component.

  In the photosensitive resin composition for an optical waveguide, the blending ratio of the component (E) is preferably 100% by mass based on the total amount of the photosensitive resin composition (however, when the organic solvent is included, the total amount excluding the organic solvent). Is 0 to 70% by mass, more preferably 0 to 60% by mass, and particularly preferably 20 to 60% by mass. If the blending ratio exceeds 70% by mass, the blending ratio of other components is decreased accordingly, the curing rate of the composition is decreased, and the mechanical strength of the film-shaped optical waveguide may be decreased. . By making the said mixture ratio 20 mass% or more, a flame retardance can be improved.

[(F) component]
The photosensitive resin composition for optical waveguides can contain an organic solvent ((F) component) as needed. By blending an organic solvent, an appropriate viscosity can be imparted and a cured film (eg, a clad layer) having a uniform thickness can be formed.
The type of the organic solvent can be appropriately selected within a range that does not impair the object and effect of the present invention, but has a boiling point within the range of 50 to 200 ° C. under atmospheric pressure, and each constituent component Those that dissolve uniformly are preferred.
Preferable examples of the organic solvent include alcohols, ethers, esters, and ketones. The preferred compound name of the organic solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethylene glycol dimethyl ether, methyl isobutyl ketone, methyl amyl ketone, toluene, xylene, and methanol. A solvent is mentioned.
The blending amount of the organic solvent is preferably 5 to 500 parts by mass with respect to 100 parts by mass as a total of the above components (A) to (C) and optional components other than the organic solvent blended as necessary. More preferably, it is 10-300 mass parts, Most preferably, it is 20-200 mass parts. If the said compounding quantity is less than 5 mass parts, adjustment of the viscosity of the photosensitive resin composition may become difficult. On the other hand, if the blending amount exceeds 500 parts by mass, it may be difficult to form a cured film (for example, a cladding layer) having a sufficient thickness.

Moreover, the photosensitive resin composition for optical waveguides may be, for example, a compound having a polymerizable reactive group other than the above components or a polymer resin (for example, an epoxy resin, an acrylic resin, a polyamide resin, a polyamideimide resin). , Polyurethane resin, polybutadiene resin, polychloroprene resin, polyether resin, polyester resin, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluoropolymer, silicone polymer), etc. Can do.
Furthermore, the photosensitive resin composition for optical waveguides can contain various additives as needed. Various additives include, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, surfactants, colorants, storage stabilizers, plasticizers. Agents, lubricants, fillers, inorganic particles, anti-aging agents, wettability improvers, antistatic agents and the like.
The photosensitive resin composition for an optical waveguide is prepared by mixing and stirring the above components according to a conventional method.

Next, the film-like optical waveguide of the present invention will be described in detail with appropriate reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing an example of the film-shaped optical waveguide of the present invention, and FIG. 2 is a flow diagram showing an example of the method for producing the film-shaped optical waveguide of the present invention.
[Structure of film-shaped optical waveguide]
In FIG. 1, the optical waveguide 24 includes a substrate 10, a core portion 20, and cladding layers (the lower cladding layer 12 and the upper cladding layer 22). The lower cladding layer 12 is formed by being laminated on the upper surface of the substrate 10, and a core portion 20 having a specific width is formed on the upper surface of the lower cladding layer 12. On the upper surfaces of the core portion 20 and the lower clad layer 12, an upper clad layer 22 is laminated. The core portion 20 is embedded in the lower cladding layer 12 and the upper cladding layer 22 that form the outer shape of the optical waveguide 24.
At least one of the core portion 20, the lower cladding layer 12, and the upper cladding layer 22 is made of a cured product of the above-described photosensitive resin composition. In particular, the lower cladding layer 12 and the upper cladding layer 22 are preferably made of a cured product of the above-described photosensitive resin composition.
The thicknesses of the lower cladding layer, the core portion, and the upper cladding layer are not particularly limited. For example, the thickness of the lower cladding layer is 1 to 200 μm, the thickness of the core portion is 3 to 200 μm, and the thickness of the upper cladding layer. Is determined to be 1 to 200 μm. Although the width | variety of a core part is not specifically limited, For example, it is 1-200 micrometers.
The refractive index of the core portion needs to be larger than any of the refractive indexes of the lower cladding layer and the upper cladding layer. For example, for light with a wavelength of 400 to 1,600 nm, the refractive index of the core portion is 1.420 to 1.650, the refractive indexes of the lower cladding layer and the upper cladding layer are 1.400 to 1.648, and The refractive index of the core portion is preferably at least 0.1% greater than the refractive index of any of the two cladding layers.

[Method for producing film-shaped optical waveguide]
The method for manufacturing the optical waveguide 24 includes a step of forming the lower clad layer 12, a step of forming the core portion 20, and a step of forming the upper clad layer 22. Among these three steps, at least one step is a step of forming a cured product by irradiating the above-described photosensitive resin composition with light.
In addition, the composition for forming each part of the lower clad layer 12, the core part 20, and the upper clad layer 22 constituting the optical waveguide is respectively a lower layer composition, a core composition, and an upper layer composition for convenience. Called.

(1) Preparation of material The component composition of each of the lower layer composition, the core composition and the upper layer composition is such that the refractive index relationship between the lower cladding layer 12, the core portion 20 and the upper cladding layer 22 is optical. It is determined so as to satisfy the conditions required for the waveguide. Specifically, two or three kinds of photocurable compositions having a difference in refractive index of an appropriate size are prepared, and among these, a photocurable composition that gives a cured film having the highest refractive index is used as a core. And other photocurable compositions are used as the lower layer composition and the upper layer composition. The lower layer composition and the upper layer composition are preferably the same photocurable composition (the composition of the present invention) in terms of economy and production management. Moreover, the composition of the present invention (however, a refractive index higher than that of the lower layer composition and the upper layer composition) can be used for the core composition.

(2) Preparation of Substrate As shown in FIG. 2A, a substrate 10 having a flat surface is prepared as a base material for forming an optical waveguide. Although it does not specifically limit as a kind of this board | substrate 10, For example, a silicon wafer, a glass substrate, PET film, a polyimide film etc. can be used.
(3) Formation process of lower clad layer In this process, the lower clad layer 12 is formed on the surface of the substrate 10.
Specifically, as shown in FIG. 2 (b), a lower layer composition (the composition of the present invention) is applied to the surface of the substrate 10, and dried or prebaked as necessary to form a lower layer thin film. Form. Next, the lower layer thin film is irradiated with light and cured to form the lower cladding layer 12 which is a cured body. In the step of forming the lower clad layer 12, it is preferable to irradiate the entire surface of the thin film with light and harden the whole.
Here, as a coating method of the composition for the lower layer, any of spin coating method, dipping method, spray method, bar coating method, roll coating method, curtain coating method, gravure printing method, silk screen method, ink jet method, etc. The method can be used. Among these, since a thin film for a lower layer having a uniform thickness can be obtained, it is preferable to employ a spin coating method.

The light for forming the lower clad layer is not particularly limited, but light in the ultraviolet to visible region of 200 to 450 nm, preferably light including ultraviolet light having a wavelength of 365 nm is usually used. Irradiation at a wavelength of 200 to 450 nm is such that the illuminance is 1 to 1,000 mW / cm ² and the irradiation amount is 0.01 to 5,000 mJ / cm ² , preferably 0.1 to 1,000 mJ / cm ^2. Done.

  Visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays and the like can be used as the type of light to be irradiated. A wavelength including ultraviolet rays of 365 nm is preferable. As an irradiation device, for example, from a lamp light source that simultaneously irradiates a wide area such as a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, an excimer lamp, and a laser light source such as a pulse, continuous light emission, or both, What produces a converging light using a mirror, a lens, and an optical fiber can be used.

It is preferable to further perform heat treatment (post-bake) so that the entire coating film is sufficiently cured after exposure. This heating condition varies depending on the component composition of the photosensitive resin composition, but is usually 30 to 300 ° C., preferably 50 to 200 ° C., for example, a heating time of 5 minutes to 72 hours.
In the formation process of the lower clad layer, the coating method of the composition, the amount of light irradiation, the type, and the light (ultraviolet) irradiation device, etc. are used in the core part formation process and the upper clad layer formation process described later. Is the same.
The post-baking conditions in the lower clad layer forming step are the same in the upper clad layer forming step described later.

(4) Core Part Formation Step This is a step of forming the core part 20 on the surface of the lower cladding layer 12.
Specifically, as shown in FIG. 2C, the core composition is applied to the surface of the lower cladding layer 12, and dried (and pre-baked) as necessary to form the core thin film 14. . Thereafter, as shown in FIG. 2D, the upper surface of the core thin film 14 is irradiated (exposed) with light 16 through a photomask 18 having a predetermined line pattern, for example, according to a predetermined pattern. Do. As a result, only the portion irradiated with light in the core thin film 14 is cured, so that other uncured portions are developed and removed, as shown in FIG. Then, a core portion 20 made of a patterned cured film is formed on the lower cladding layer 12.
The details of the development processing in this step are as follows.
The development process is carried out in accordance with a predetermined pattern, and for the thin film selectively cured, using the difference in solubility between the cured portion and the uncured portion, only the uncured portion is developed using a developer. The removal is performed. That is, after pattern exposure, the uncured portion is removed and the cured portion is left, resulting in the formation of the core portion.

As the developer used for the development processing, an organic solvent, or sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, Triethylamine, methyldiethylamine, N-methylpyrrolidone, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo [5.4.0] -7- An alkaline aqueous solution composed of alkalis such as undecene and 1,5-diazabicyclo [4.3.0] -5-nonane can be used.
In addition, when using aqueous alkali solution as a developing solution, the density | concentration is 0.05-25 mass% normally, Preferably it is 0.1-3.0 mass%. Moreover, it is also preferable to add an appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant or the like to the alkaline aqueous solution and use it as a developer.
The development time is usually 30 to 600 seconds. As a developing method, a known method such as a liquid piling method, a dipping method, or a shower developing method can be employed.
When an organic solvent is used as the developer, it is directly air-dried. When an alkaline aqueous solution is used as the developer, it is washed with running water, for example, for 30 to 90 seconds, and then air-dried with compressed air or compressed nitrogen. By doing so, the organic solvent or moisture is removed, and a patterned thin film is formed.
After the formation of the patterned thin film (patterning portion), in order to further cure the patterning portion, a post baking process is performed using a heating device such as a hot plate or an oven at a temperature of 30 to 200 ° C. for 5 to 600 minutes, for example. In this case, the core portion 20 that is a cured body is formed.

In this step, the method of irradiating light according to a predetermined pattern is not limited to the method using the photomask 18 composed of a light transmitting portion and a non-transmitting portion, and for example, any of the methods a to c shown below May be adopted.
a. A method using electro-optical means for forming a mask image composed of a light transmitting region and a light non-transmitting region in accordance with a predetermined pattern using the same principle as that of a liquid crystal display device.
b. A method of irradiating light through an optical fiber corresponding to a predetermined pattern in the light guide member using a light guide member formed by bundling a large number of optical fibers.
c. A method of irradiating a photosensitive resin composition while scanning a laser beam or convergent light obtained by a condensing optical system such as a lens or a mirror.

(5) Upper Cladding Layer Formation Step This is a step of forming the upper cladding layer 22 on the surfaces of the core portion 20 and the lower cladding layer 12.
Specifically, the upper layer composition is applied to the surfaces of the core portion 20 and the lower clad layer 12, and dried or prebaked as necessary to form an upper layer thin film. When the upper thin film is cured by irradiation with light, an upper cladding layer 22 is formed as shown in FIG. The upper cladding layer 22 is preferably post-baked. If post-baking is performed, the upper clad layer 22 having large hardness and excellent heat resistance can be obtained.
Thereafter, if the substrate 10 is not peeled off ((g) in FIG. 2) or is peeled off (not shown), a film-like optical waveguide is obtained.

Hereinafter, the present invention will be specifically described by way of examples.
[(A) Preparation of fluorine-containing unsaturated compound]
(1) Synthesis of hydroxyl group-containing fluorine-containing polymer After a 2.0-liter stainless steel autoclave with an electromagnetic stirrer was sufficiently replaced with nitrogen gas, 11544 g of ethyl acetate, 3464 g of perfluoro (propyl vinyl ether), 938 g of ethyl vinyl ether, hydroxy After 1145 g of ethyl vinyl ether and 37.5 g of lauroyl peroxide were charged and cooled to −50 ° C. with dry ice-methanol, oxygen in the system was removed again with nitrogen gas.
Next, 1953 g of hexafluoropropylene was charged and the temperature increase was started. The pressure when the temperature in the autoclave reached 60 ° C. was 5.1 × 10 ⁵ Pa. Thereafter, the reaction was continued with stirring at 70 ° C. for 20 hours, and when the pressure dropped to 1.6 × 10 ⁵ Pa, the autoclave was cooled with water to stop the reaction. After reaching room temperature, unreacted monomers were released and the autoclave was opened to obtain a polymer solution having a solid content concentration of 32.6%. The obtained polymer solution was put into methanol to precipitate a polymer, washed with methanol, and vacuum dried at 50 ° C. to obtain about 5 kg of a hydroxyl group-containing fluoropolymer.
(2) Synthesis of ethylenically unsaturated group-containing fluoropolymer J-1 (methacryl-modified fluoropolymer) (component (A)) 1 liter separable equipped with electromagnetic stirrer, glass condenser and thermometer Into the flask, 100 g of the hydroxyl group-containing fluoropolymer obtained in (1) above was charged, 0.17 g of 2,6-di-t-butylmethylphenol and 750 g of methyl isobutyl ketone (MIBK) as a polymerization inhibitor, Stirring was performed until the hydroxyl group-containing fluoropolymer was dissolved in MIBK at 20 ° C., and the solution became transparent and uniform. Next, 26.5 g of 2-methacryloyloxyethyl isocyanate was added to this system and stirred until the solution became homogeneous, then 0.25 g of dibutyltin dilaurate was added to start the reaction, and the temperature of the system was changed to 55 to 55. The fluorine-containing unsaturated compound J-1 having the composition (unit: mol%) shown in Table 1 was obtained by maintaining the temperature at 65 ° C. and continuing stirring for 5 hours.
A fluorine-containing unsaturated compound J-2 having the composition (unit: mol%) shown in Table 1 was obtained in the same manner except that the blending amounts of each component, catalyst, and the like were appropriately changed.

[Examples 1 to 4, Comparative Examples 1 and 2]
The photosensitive resin composition was prepared by mix | blending each component by the mixing | blending ratio shown in Table 2, and mixing uniformly.
Subsequently, flame retardance was evaluated by the following method using the obtained photosensitive resin composition.
The results are shown in Table 2.
(Flame retardance)
The photosensitive composition was apply | coated on PET film using the applicator, and it dried for 5 minutes at the temperature of 120 degreeC, and formed the photosensitive resin composition layer. Thereafter, the photosensitive resin composition layer was cured by irradiating with ultraviolet rays using a metal halide lamp under the conditions of an illuminance of 200 mW / cm ² and an irradiation light amount of 1.0 J / cm ² to obtain a cured film having a thickness of 70 μm. . After peeling the cured film from the PET film, a test piece having a width of 5 mm and a length of 50 mm was obtained from the cured film.
When the obtained specimen is fixed with a clamp so that the longitudinal direction is vertical, the flame of the lighter (butane gas, flow rate 5 cc / min, flame length 12 mm) from the lower end is indirect flame for 2 seconds. Thereafter, a case where the test piece was not burned out was designated as “◯”, and a case where the test piece was burned out was designated as “X”.

  From Table 1, it is understood that excellent flame retardancy is obtained in Examples 1 to 4 using the photosensitive resin composition for an optical waveguide of the present invention. On the other hand, in Comparative Example 1 that does not contain the component (B) and Comparative Example 2 that does not contain the component (A), it can be seen that the flame retardancy is inferior.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 12 Lower clad layer 14 Core thin film 16 Light 18 Photomask 20 Core portion 22 Upper clad layer 24 Optical waveguide

Claims (7)

An optical waveguide having a core portion and a cladding layer, wherein at least one of the core portion and the cladding layer is made of a cured product of a photosensitive resin composition for an optical waveguide containing the following components (A) to (C): A film-like optical waveguide characterized by the above.
(A) A compound having in the molecule at least one fluorine atom and at least one polymerizable carbon-carbon double bond (excluding those containing a phosphorus atom).
(B) A compound having at least one phosphorus atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a fluorine atom).
(C) Photo radical polymerization initiator   2. A film-shaped optical waveguide comprising a lower cladding layer, a core portion, and an upper cladding layer, wherein the lower cladding layer and the upper cladding layer are made of a cured product of the photosensitive resin composition for an optical waveguide. The film-form optical waveguide as described.   In the photosensitive resin composition for an optical waveguide, the blending ratio of each of the component (A), the component (B), and the component (C) is the total amount of the photosensitive resin composition (however, the organic solvent is included). 3. The film-shaped optical waveguide according to claim 1, wherein the total amount excluding the organic solvent is 5 to 80% by mass, 5 to 80% by mass, and 0.1 to 10% by mass. .   The film-form light according to any one of claims 1 to 3, wherein the photosensitive resin composition for an optical waveguide further comprises (D) a radical polymerizable compound other than the components (A) and (B). Waveguide.   The film-like optical waveguide according to any one of claims 1 to 4, wherein the photosensitive resin composition for an optical waveguide further contains (E) a polyimide silicone resin.   The film-like optical waveguide according to any one of claims 1 to 5, wherein the photosensitive resin composition for an optical waveguide further contains (F) an organic solvent. (A) A compound having at least one fluorine atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a phosphorus atom),
(B) a compound having at least one phosphorus atom and at least one polymerizable carbon-carbon double bond in the molecule (excluding those containing a fluorine atom), and (C) a photoradical. Polymerization initiator,
A photosensitive resin composition for an optical waveguide comprising:

Images