JP2003195079A - Radioactive ray hardening composition for forming optical waveguide, optical waveguide, and method of manufacturing optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a radioactive ray hardening composition for forming an optical waveguide, an optical waveguide using thereof, and a method of manufacturing an optical waveguide, in more detail, to obtain a shape of a waveguide suitable for the shape for a purpose, an optical waveguide which has an excellent transmission characteristics, and a method of manufacturing an optical waveguide. <P>SOLUTION: The radioactive ray hardening composition for forming an optical waveguide is characterized by the fact that the composition includes (A) a vinyl based polymer having a polymeric group, (B) a compound having two or more polymeric reactive groups in molecule and (C) a starting agent of a radioactive polymerization. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radiation-curable composition for forming an optical waveguide, an optical waveguide using the same, and a method for producing the optical waveguide. More specifically, the present invention relates to a waveguide shape suitable for a target shape and an optical waveguide having excellent transmission characteristics, and a method for manufacturing the optical waveguide.

[0002]

2. Description of the Related Art With the advent of the multimedia era, optical waveguides have been attracting attention as optical transmission media due to the demand for large capacity and high speed of information processing in optical communication systems and computers. A silica-based waveguide is typical as such an optical waveguide, and is generally manufactured by the following steps. A lower clad layer made of a glass film is formed on a silicon substrate by a method such as a flame deposition method (FHD) or a CVD method. An inorganic thin film with a high refractive index is formed on the lower clad layer, and this thin film is formed by the reactive ion etching method (R
A core portion is formed by patterning using IE). Further, the upper clad layer is formed by the flame deposition method. However, such a method of manufacturing a silica-based waveguide has problems that a special manufacturing apparatus is required and that manufacturing time is long. In addition, JP 2000
-180643, a silicone-based composition containing a photopolymerizable component is irradiated with a predetermined amount of light to cure a predetermined portion, and at the same time, an unexposed portion is developed to form a core portion and the like. , Have proposed a method of manufacturing an optical waveguide. According to the method for producing an optical waveguide using such a photocurable composition, as compared with the conventional method for producing a silica-based waveguide, only by developing after irradiating a predetermined amount of light, a short time, Further, it is possible to obtain an advantage that the optical waveguide can be manufactured at low cost. However, in the method of manufacturing an optical waveguide using the above-mentioned photocurable composition, there are restrictions such as using a special silicone-based oligomer.

[0003]

SUMMARY OF THE INVENTION The present invention has been made under the circumstances described above, and an optical waveguide having an excellent waveguide shape and an excellent transmission characteristic is formed by using a general-purpose organic material. It is an object of the present invention to provide a radiation-curable composition capable of forming a resin, an optical waveguide using the same, and a method capable of efficiently producing such an optical waveguide.

[0004]

[Means for Solving the Problems] (A) The following general formula (1)
A polymer having a structure represented by (hereinafter referred to as "copolymer (A)")

[Chemical 3] [R ¹ , R ² and R ³ are hydrogen or an alkyl group having a carbon chain of 1 to 12, X is a group having a carboxyl group, Y is a group having a polymerizable group, Z is an organic group other than X and Y. A radiation-curable composition for forming an optical waveguide, which comprises (B) a compound having two or more polymerizable reactive groups in the molecule and (C) a radiation polymerization initiator, formed using the same. And a method for manufacturing the optical waveguide.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Radiation-curable composition (A) component for forming an optical waveguide The copolymer (A) used in the present invention can be obtained by the following two methods. It can be obtained by radical copolymerizing (a) a radically polymerizable compound having a carboxyl group, (b) a radically polymerizable compound having a cyclic ether, and (c) another radically polymerizable compound in a solvent. After radical copolymerizing (a) a radically polymerizable compound having a carboxyl group and (c) another radically polymerizable compound in a solvent, (d) a radically polymerizable compound having a reactive functional group is added to a polymer side chain. It can be obtained by adding to a part of the carboxyl group of. Examples of the radically polymerizable compound (a) having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid; 2 -Succinoloyl ethyl methacrylate,
A methacrylic acid derivative having a carboxyl group and an ester bond, such as 2-maleinoloylethyl methacrylate and 2-hexahydrophthaloylethylmethacrylate, can be used. These compounds may be used alone or 2
A combination of two or more species can be used. Among these, acrylic acid, methacrylic acid and 2-hexahydrophthaloylethylmethacrylate are preferable, and acrylic acid and methacrylic acid are more preferable.

The proportion of the radically polymerizable compound having a carbonyl group in the copolymer (A) is 5 to 50% by weight, preferably 10 to 40% by weight. If it is less than 5% by weight, it becomes difficult to dissolve when the composition is cured by light irradiation and subjected to alkali development treatment, and when used as a core portion of an optical waveguide, a core shape as designed cannot be obtained, Sufficient transmission characteristics cannot be obtained. On the other hand, even if it exceeds 50% by weight, the shape as designed cannot be obtained.
Examples of the radically polymerizable compound (b) having the cyclic ether as a substituent include glycidyl (meth) acrylate, α-ethylglycidyl (meth) acrylate, α
-N-propylglycidyl (meth) acrylate, α-
n-Butylglycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, 2-ethylglycidyl (meth) acrylate, 2-propylglycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 3,4 -Epoxyheptyl (meth)
Acrylate, α-ethyl-6,7-epoxyheptyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, (2-ethyl-2-oxetanyl) methyl (meth) acrylate, (2-methyl-2 -Oxetanyl) methyl (meth) acrylate,
2- (2-Ethyl-2-oxetanyl) ethyl (meth)
Acrylate, 2- (2-methyl-2-oxetanyl)
Ethyl (meth) acrylate, 3- (2-ethyl-2-
Oxetanyl) propyl (meth) acrylate, 3-
(Meth) acrylic acid esters such as (2-methyl-2-oxetanyl) propyl (meth) acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, α-methyl-o -Vinylbenzyl glycidyl ether,
α-methyl-m-vinylbenzyl glycidyl ether, α-
Methyl-p-vinylbenzyl glycidyl ether, 2,3-diglycidyloxymethylstyrene, 2,4-diglycidyloxymethylstyrene, 2,5-diglycidyloxymethylstyrene, 2,6-diglycidyloxymethylstyrene, 2 , 3,
4-triglycidyloxymethylstyrene, 2,3,5-triglycidyloxymethylstyrene, 2,3,6-triglycidyloxymethylstyrene, 3,4,5-triglycidyloxymethylstyrene, 2,4,6- Examples thereof include styrenes such as triglycidyloxymethylstyrene. Of these,
3,4-Epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, p-vinylbenzylglycidyl ether and the like are preferably used.

The other radically polymerizable compound (c) is
Mainly used for the purpose of appropriately controlling the mechanical properties and refractive index of the copolymer (A). Here, "other" means a radically polymerizable compound other than the radically polymerizable compound described above. Such other radically polymerizable compound (c) is preferably (meth) acrylic acid alkyl esters, (meth) acrylic acid aryl esters, dicarboxylic acid diesters, aromatic vinyls, conjugated diolefins, Examples thereof include nitrile group-containing polymerizable compounds, chlorine-containing polymerizable compounds, amide bond-containing polymerizable compounds, fatty acid vinyls and the like. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate and the like (meth ) Acrylic acid alkyl ester; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate and benzyl (meth) acrylate; dicarboxylic acid diester such as diethyl maleate, diethyl fumarate, and itaconic acid diethyl ester; styrene, α-methylstyrene ,
Aromatic vinyls such as m-methylstyrene, p-methylstyrene, vinyltoluene and p-methoxystyrene;
Conjugated diolefins such as 1,3-butadiene, isoprene and 1,4-dimethylbutadiene, nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; acrylamide, An amide bond-containing polymerizable compound such as methacrylamide; a fatty acid vinyl such as vinyl acetate can be used. These compounds alone,
Alternatively, two or more kinds can be used in combination, and among these, methyl (meth) acrylate, n-butyl (meth) acrylate, styrene, α-methylstyrene and the like are particularly preferable. The proportion of the other radically polymerizable compound in the copolymer (A) is 5 to 80% by weight, preferably 20 to 70% by weight.

Examples of the polymerization solvent used when synthesizing the copolymer (A) include alcohols such as methanol, ethanol, ethylene glycol, diethylene glycol and propylene glycol; tetrahydrofuran,
Cyclic ethers such as 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 Alkyl ethers of polyhydric alcohols such as monomethyl ether and propylene glycol monoethyl ether; Alkyl ethers of polyhydric alcohols such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate and propylene glycol ethyl ether acetate Le acetates; toluene, aromatic hydrocarbons such as xylene; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4
-Hydroxy-4-methyl-2-pentanone, ketones such as diacetone alcohol; ethyl acetate, butyl acetate, ethyl lactate, ethyl 2-hydroxypropionate,
Ethyl 2-hydroxy-2-methylpropionate, 2-
Ethyl hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-
Esters such as methyl 3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate and methyl 3-ethoxypropionate can be mentioned. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferable.

As a polymerization catalyst in radical copolymerization, a usual radical polymerization initiator can be used, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethyl). Valeronitrile), 2, 2
Azo compounds such as'-azobis- (4-methoxy-2'-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1'-bis- (t-butylperoxy)
Examples thereof include organic peroxides such as cyclohexane, hydrogen peroxide and the like. When a peroxide is used as the radical polymerization initiator, a redox type initiator may be used in combination with a reducing agent.

In the method, the radically polymerizable compound (d) having a reactive functional group to be added to the carboxyl group of the side chain of the copolymer (A) is, for example, glycidyl (meth) acrylate or α-ethylglycidyl ( (Meth) acrylate, α-n-propylglycidyl (meth) acrylate, α-n-butylglycidyl (meth)
Acrylate, 2-methylglycidyl (meth) acrylate, 2-ethylglycidyl (meth) acrylate, 2-
Propylglycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 3,4-epoxyheptyl (meth) acrylate, α-ethyl-6,7-
Epoxyheptyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate and other epoxy group-containing (meth) acrylic acid esters, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl Glycidyl ether, α-methyl-o-vinylbenzyl glycidyl ether,
α-methyl-m-vinylbenzyl glycidyl ether, α-
Methyl-p-vinylbenzyl glycidyl ether, 2,3-diglycidyloxymethylstyrene, 2,4-diglycidyloxymethylstyrene, 2,5-diglycidyloxymethylstyrene, 2,6-diglycidyloxymethylstyrene, 2 , 3,
4-triglycidyloxymethylstyrene, 2,3,5-triglycidyloxymethylstyrene, 2,3,6-triglycidyloxymethylstyrene, 3,4,5-triglycidyloxymethylstyrene, 2,4,6- Examples thereof include styrenes having an epoxy group such as triglycidyloxymethylstyrene. Of these, 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, p
-Vinylbenzyl glycidyl ether and the like are preferably used.

The solvent used for the addition reaction may be the same as the solvent used for the copolymer. When carrying out the addition reaction, a thermal polymerization inhibitor can be added in order to suppress the polymerization reaction due to heat. Examples of the thermal polymerization inhibitor include pyrogallol, benzoquinone, hydroquinone, methylene blue, tert-butylcatechol, monobenzyl ether, methoxyphenol, amylquinone, amyloxyhydroquinone, n-butylphenol,
Examples thereof include phenol and hydroquinone monopropyl ether. The amount of these compounds used is preferably 5 parts by weight or less with respect to 100 parts by weight of the copolymer.

(2) Component (B) Compound (B) having two or more polymerizable reactive groups in the molecule
Is a compound that undergoes thermal polymerization and / or photopolymerization, and examples thereof include the compounds shown below.

A compound having two or more ethylenically unsaturated groups in the molecule; a compound having two or more (meth) acryloyl groups or vinyl groups in the molecule can be used. Examples of such a compound include ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6- Xanthyl di (meth) acrylate, neopentyl glycol di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, bis (hydroxymethyl) tricyclodecane di (meth) acrylate, ethylene of bisphenol A Di (meth) of diol which is an adduct of oxide or propylene oxide
Acrylate, hydrogenated bisphenol A ethylene oxide or propylene oxide adduct diol di (meth) acrylate, bisphenol A diglycidyl ether epoxy (meth) acrylate added with (meth) acrylate, polyoxyalkylenated Examples include bisphenol A diacrylate and the like.
Furthermore, as the (meth) acrylate containing 3 or more (meth) acryloyl groups in the molecule, a compound 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. are mentioned. Further, polyether acryl oligomer having polyester, polyester, polyurethane skeleton in the main chain, polyester acryl oligomer, polyurethane acryl oligomer, or polyepoxy acryl oligomer can also be used.
These commercially available products include Uupimer UV SA100
2, SA2007 (above, Mitsubishi Chemical), Viscoat #
195, # 230, # 215, # 260, # 295, #
300, # 335HP, # 360, # 400, # 54
0, # 700, 3PA, GPT (above, manufactured by Osaka Organic Chemical Industry), light acrylate 4EG-A, 9EG-A,
NP-A, DCP-A, BP-4EA, BP-4PA,
PE-3A, PE-4A, DPE-6A (above, Kyoeisha Chemical Co., Ltd.), KAYARAD MANDA, HX-22
0, HX-620, R-551, R-712, R-60
4, R-684, PET-30, GPO-303, TM
PTA, DPHA, D-310, D-330, DPCA
-20, -30, -60, -120 (above, Nippon Kayaku), Aronix M208, M210, M215, M
220, M240, M305, M309, M310, M
315, M325, M400, M1200, M610
0, M6200, M6250, M7100, M803
0, M8060, M8100, M8530, M856
0, M9050 (above, manufactured by Toagosei), Lipoxy VR-
77, VR-60, VR-90 (above, Showa High Polymer), Ebecryl 81, 83, 600, 629, 6
45, 745, 754, 767, 701, 755, 70
5, 770, 800, 805, 810, 830, 45
0, 1830, 1870 (above, made by Daicel UCB),
Beam sets 575, 551B, 502H, 102 (above, manufactured by Arakawa Chemical Co., Ltd.) and the like can be mentioned.

Compounds having two or more cyclic ethers in the molecule; Among oxirane compounds, oxetane compounds, oxolane compounds and the like, compounds having two or more cyclic ethers in the molecule can be used. For example, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-) as oxirane compounds
5,5-spiro-3,4-epoxy) cyclohexane-
Meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,3
4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ', 4'-epoxy-6'-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), di Cyclopentadiene diepoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4-epoxycyclohexanecarboxylate), epoxidized tetrabenzyl alcohol, lactone-modified 3,4-epoxycyclohexylmethyl-3 ', 4'-Epoxycyclohexanecarboxylate, lactone-modified epoxidized tetrahydrobenzyl alcohol, cyclohexene oxide, bisphenol A diglycidyl ether, bisphenol F diglycidyl Ether, bisphenol S
Diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol AD diglycidyl ether,
Brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, epoxy novolac resin, 1,4-butanediol diglycidyl ether,
1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers; for ethylene glycol, propylene glycol, aliphatic polyhydric alcohols such as glycerin 1
Or polyglycidyl ethers of polyether polyols obtained by adding two or more alkylene oxides; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; phenol, cresol, Butylphenol or monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these;
Glycidyl esters of higher fatty acids; epoxidized soybean oil, butyl epoxystearate, octyl epoxystearate, epoxidized linseed oil and the like can be mentioned. As the oxetane compound, 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,
3- (2-methylenyl) propanediylbis (oxymethylene)) bis- (3-ethyloxetane), 1,4-
Bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanyl) Methoxy) methyl]
Propane, ethylene glycol bis (3-ethyl-3-
Oxetanylmethyl) ether, dicyclopentenyl bis (3-ethyl-3-oxetanylmethyl) ether,
Triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether,
Tricyclodecanediyldimethylene (3-ethyl-3-
Oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-) Oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3)
-Oxetanylmethyl) ether and the like can be exemplified, and these can be used alone or in combination of two or more.

These commercially available products include Epolite 40
E, 100E, 70P, 1500NP, 100MF, 4
000, 3002 (above, Kyoeisha Chemical Co., Ltd.), Celoxide 2021, 2081, GT301, GT401, Epolide CDM, PB3600, Epofriend A100.
5, A1010, A1020 (above, manufactured by Daicel Chemical Industries), Denacol 611, 612, 512, 521, 4
11, 421, 313, 321 (above, manufactured by Nagase Kasei)
Etc. In addition, the above-mentioned ethylenically unsaturated group,
And a compound containing at least one or more both reactive groups of cyclic ether in the molecule. Examples thereof include glycidyl (meth) acrylate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, and 3,4-epoxycyclohexylmethyl (meth) acrylate.

These (B) components may be used alone or in combination of two or more kinds, and it is particularly preferable to use a compound containing two or more ethylenically unsaturated groups in the molecule.
It is preferably 30 with respect to 100 parts by weight of the copolymer (A).
To 150 parts by weight, more preferably 50 to 130 parts by weight. If the amount is less than 30 parts by weight, the desired waveguide shape may not be obtained when the optical waveguide is formed.
When it exceeds the amount by weight, the compatibility with the copolymer (A) deteriorates, and the surface of the cured product may be roughened.

The component (C) radiation polymerization initiator is an initiator capable of generating an active species capable of polymerizing the component (B) by radiation. Here, the radiation means ionizing radiation such as infrared rays, visible rays, ultraviolet rays, and X-rays, electron beams, α rays, β rays, and γ rays. Therefore, the radiation polymerization initiator which is the component (C) is required, and if necessary, a photosensitizer is further added. Radiation polymerization initiators can be broadly classified into those that decompose by light irradiation to generate radicals (radiation radical polymerization initiators) and those that generate cations (radiation cationic polymerization initiators). Examples of the radiation 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, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-
1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like can be mentioned. .

As a commercial product of a radiation radical polymerization initiator
Is, for example, Irgacure 184, 369, 651,
500, 819, 907, 784, 2959, CGI1
700, CGI1750, CGI11850, CG24
-61, Darocurl 116, 1173 (above, Chi
Ba Specialty Chemicals), Lucirin
TPO, TPO-L (above, manufactured by BASF), Yubecryl
P36 (manufactured by UCB) and the like. Radiation cation weight
As the compounding initiator, a structure represented by the following general formula (2) is used.
The onium salt which it has can be mentioned. This onium
A salt is a compound that releases a Lewis acid when exposed to light.
Is.           [R¹² _a R¹³ _b R¹⁴ _c R¹⁵ _d W]^{+ m}[MX_{n + m}]^-m      (2) [In the formula, the cation is an onium ion, and W is S, S
e, Te, P, As, Sb, Bi, O, I, Br, Cl
Or N≡N and R¹², R¹³, R¹⁴And R ¹⁵Is the same
One or a different organic group, where a, b, c and d are
Each is an integer of 0 to 3, and (a + b + c + d) is W
Is equal to the valence of. M is a halide complex [MX_{n + m}]
Is a metal or metalloid that constitutes the central atom of
For example, B, P, As, Sb, Fe, Sn, Bi, Al, C
a, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc.
How is it? X is a halogen atom such as F, Cl or Br
And m is the net charge of the halide complex ion
Where n is the valence of M. ] As a specific example of the onium ion in the general formula (2),
Is diphenyliodonium, 4-methoxydiphenyl
Iodonium, bis (4-methylphenyl) iodonium
Bis (4-tert-butylphenyl) iodonium,
Bis (dodecylphenyl) iodonium, triphenyl
Sulfonium, diphenyl-4-thiophenoxypheni
Rusulfonium, bis [4- (diphenylsulfonyl)
E) -phenyl] sulfide, bis [4- (di (4-
(2-hydroxyethyl) phenyl) sulfonio) -fu
[Phenyl] sulfide, η^Five-2,4- (cyclopentadi
Phenyl) [1,2,3,4,5,6-η]-(methyl ether
Chill) -benzene] -iron (1+) and the like. the above
Anion (MX in general formula (2)_{n + m}) Concrete example
As tetrafluoroborate (BF_Four ^-), Hexa
Fluorophosphate (PF₆ ^-), Hexafluoroan
Timonate (SbF₆ ^-), Hexafluoroarsenate
(AsF₆ ^-), Hexachloroantimonate (SbCl
₆ ^-) And the like.

As an onium salt which can be used as a radiation cationic polymerization initiator, in the general formula (2), instead of [MX _{n + m} ], a general formula: [MX _n (OH) ⁻ ] (3) ( Here, M, X and n are as defined in relation to the general formula (2)), anion represented by the general formula (2), perchlorate ion (ClO ₄ ⁻ ), trifluoromethanesulfonate ion (CF ₃ SO ₃ ⁻ ), Fluorosulfonate ion (FS
O ₃ ^-), toluenesulfonic acid ion, trinitrobenzene sulfonic acid ion, and other onium salts having an anion such as trinitrotoluene sulfonate ion. Examples of commercially available radiation cationic polymerization initiators include UVI-6950, UVI-6970, UV.
I-6974, UVI-6990 (above, Union Carbide Corporation), ADEKA OPTOMER SP-150, SP-1
51, SP-170, SP-171 (above Asahi Denka Kogyo KK), Irgacure 261 (above Ciba Geigy), CI-2481, CI-2624, CI-2
639, CI-2064 (above, Nippon Soda Co., Ltd.), C
D-1010, CD-1011, CD-1012 (above, Sartomer), DTS-102, DTS-10
3, NAT-103, NDS-103, TPS-10
2, TPS-103, MDS-103, MPI-10
3, BBI-101, BBI-102, BBI-103
(Midori Kagaku Co., Ltd.), Degacure K1
26 (manufactured by Degussa) and the like. The radiation polymerization initiators may be used alone or in combination of two or more to form the component (C).

The content ratio of the component (C) in the resin composition of the present invention is usually preferably 0.1 to 10% by weight,
2-5% by weight is particularly preferred. If the content ratio of the component (C) is less than 0.1% by weight, curing may not proceed sufficiently and a problem may occur in the transmission characteristics of the optical waveguide. On the other hand, 1
If it exceeds 0% by weight, the initiator may adversely affect the long-term transmission characteristics. In the radiation curable composition, it is also preferable to use a photosensitizer in combination with the above-mentioned radiation polymerization initiator. The reason for this is that the energy ray such as light can be more effectively absorbed by using the photosensitizer together. Such photosensitizers include thioxanthone, diethylthioxanthone and thioxanthone derivatives; anthraquinone, bromanthraquinone and anthraquinone derivatives; anthracene, bromanthracene and anthracene derivatives;
Perylene and derivatives of perylene; xanthone, thioxanthone, and derivatives of thioxanthone; coumarin, ketocoumarin, and the like. For these photosensitizers, it is necessary to select a suitable sensitizer depending on the type of the initiator.

The resin composition of the present invention contains, in addition to the above-mentioned components, one polymerizable reactive group in the molecule, if necessary, within a range that does not impair the characteristics of the resin composition of the present invention. Compounds and polymer resins such as epoxy resin, acrylic resin, polyamide resin, 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-based polymers Polymers can be incorporated. Furthermore, in addition to the above components, if necessary, various additives such as antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improving agents, thermal polymerization inhibitors, leveling agents, surfactants. , Colorant, storage stabilizer,
A plasticizer, a lubricant, a filler, inorganic particles, an antiaging agent, a wettability improver, an antistatic agent and the like can be added if necessary. Here, as the antioxidant, for example, Irga
nox1010, 1035, 1076, 1222 (above, manufactured by Ciba Specialty Chemicals), Anti
gene P, 3C, FR, Sumilizer (manufactured by Sumitomo Chemical Co., Ltd.) and the like. Examples of the ultraviolet absorber include T
inuvin P, 234, 320, 326, 327,
328, 329, 213 (above, manufactured by Ciba Specialty Chemicals), Seesorb 102, 103, 1
10, 501, 202, 712, 704 (above, manufactured by Cipro Kasei) and the like, and examples of the light stabilizer include Ti.
Nuvin 292, 144, 622LD (above, Ciba Specialty Chemicals), Sanor LS77
0 (manufactured by Sankyo), 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, as commercially available products SH6062, 6030 (above, manufactured by Toray Dow Corning Silicone), KBE903, 603, 403.
(Above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like, examples of the coating surface improver include silicone additives such as dimethylsiloxane polyether, and commercially available products include DC-5.
7, DC-190 (above, manufactured by Dow Corning), SH-28PA, SH-29PA, SH-30PA, SH-1
90 (above, 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 (above, Nippon Unicar make) etc. are mentioned.

The resin composition of the present invention preferably further contains an organic solvent as the component (D). By adding the organic solvent, the storage stability of the radiation curable composition is improved and an appropriate viscosity can be obtained, so that an optical waveguide having a uniform thickness can be formed. The type of the organic solvent, the purpose of the present invention, can be selected within a range that does not impair the effect, usually an organic compound having a boiling point under atmospheric pressure in the range of 50 ~ 200 ℃, It is preferably an organic compound capable of uniformly dissolving each component. Specifically, the organic solvent used when preparing the copolymer of the component (A) can be used. Preferred organic solvents include alcohols, ethers, esters, and ketones, and more preferred organic solvents include propylene glycol monomethyl ether, ethyl lactate, methyl isobutyl ketone, methyl amyl ketone, toluene, xylene, and At least one solvent selected from the group consisting of methanol. The content of the organic solvent is 10 to 5 when the total amount of the radiation curable composition is 100 parts by weight.
A value within the range of 00 parts by weight is preferable. This is because if the amount of the organic solvent added is less than 10 parts by weight, it may be difficult to adjust the viscosity of the radiation-curable composition. On the other hand, if the amount of the organic solvent added is more than 500 parts by weight, it is sufficient. This is because it may be difficult to form an optical waveguide or the like having a thickness.

In manufacturing the optical waveguide, at least one step includes a step of forming each of the lower clad layer, the core portion and the upper clad layer.
This is a step of curing the radiation curable composition with radiation. 1. Preparation of radiation-curable composition lower clad layer constituting the optical waveguide, radiation-curable composition for forming the core portion and the upper clad layer, that is, the lower layer composition, the core composition and the upper layer composition, Each of the curable compositions described above can be prepared by mixing and stirring according to a conventional method.
Further, as the prepared lower layer composition, core composition and upper layer composition, respectively, the relationship of the refractive index of each part finally obtained, in order to satisfy the conditions required for the optical waveguide, It is preferable to use different radiation curable compositions. Therefore, by appropriately selecting the types and blending amounts of the components (A) and (B), it is possible to obtain a radiation curable composition capable of obtaining a cured film having a different refractive index. Then, using a radiation curable composition of two or three types such that the difference in refractive index has an appropriate size, the radiation curable composition that gives a cured film with the highest refractive index as the composition for the core, and other A radiation curable composition is preferably used as the lower layer composition and the upper layer composition. However, the lower layer composition and the upper layer composition may be the same radiation-curable composition, and it is usually the same composition, which is economically advantageous and facilitates production control. Therefore, it is more preferable. Further, when preparing each radiation curable composition, its viscosity is adjusted to 1 to 10,000 cps (2
It is preferable that the value is within the range of 5 ° C., 5 to 8,0
A value within the range of 00 cps (25 ° C.) is more preferable, and a value within the range of 10 to 5,000 cps (25 ° C.) is further preferable. The reason is that if the viscosity of each radiation curable composition is out of these ranges, it may be difficult to handle or it may be difficult to form a uniform coating film. The viscosity of the radiation curable composition can be appropriately adjusted by the blending amount of the above composition and the organic solvent.

Hereinafter, embodiments of the optical waveguide and the method for manufacturing the optical waveguide of the present invention will be specifically described with reference to the drawings. Basic Optical Waveguide Configuration FIG. 1 is a cross-sectional view showing the basic configuration of an optical waveguide configured by applying a radiation curable composition. As shown in FIG. 1, the optical waveguide 10 includes a substrate 12 extending in a direction perpendicular to the plane of the drawing (depth direction), a lower clad layer 13 formed on the surface of the substrate 12, and a lower clad layer 13 formed on the lower clad layer 13. It is configured to include a formed core portion 15 having a specific width, and an upper clad layer 17 formed by being laminated on the lower clad layer 13 including the core portion 15.
The core portion 15 is covered with the lower clad layer 13 and the upper clad layer 17 including the side portions thereof so that the waveguide loss is reduced, and is in a state of being buried as a whole. In the optical waveguide having the above-described thickness and width, the thicknesses of the lower clad layer, the upper clad layer, and the core part are not particularly limited. 200 μm, thickness of core part is 3 to 20
It is preferable that the thickness of the upper clad layer is 0 μm and the thickness of the upper clad layer is 1 to 200 μm. The width of the core portion is not particularly limited, but may be, for example, 1 to 2
It is preferable to set the value within the range of 00 μm. Refractive Index It is also necessary to make the refractive index of the core portion higher than that of both the lower and upper cladding layers.
Therefore, for light having a wavelength of 400 to 1,600 nm, the refractive index of the core portion is set to a value within the range of 1.420 to 1.650, and the refractive indices of the lower clad layer and the upper clad layer are 1. It is preferable to set the value within the range of 400 to 1.648. Further, the refractive index of the core portion is preferably larger than that of the cladding layer, and particularly, the refractive index of the core portion is preferably set to a value that is at least 0.1% larger than the refractive index of the cladding layer.

Method of Forming Optical Waveguide The optical waveguide 10 is formed through the steps shown in FIG. That is, all of the lower clad layer 13, the core portion 15 and the upper clad layer (not shown) are formed by applying a radiation curable composition for forming these layers and then radiation curing. Preferably. In the following formation examples, the lower clad layer, the core portion and the upper clad layer, a lower layer composition which is a radiation-curable composition to obtain a cured product having a different refractive index after curing, a core composition, Also, description will be given assuming that it is formed from the composition for the upper layer. Preparation of Substrate First, as shown in FIG. 2A, a substrate 12 having a flat surface is prepared. The type of the substrate 12 is not particularly limited, but for example, a silicon substrate or a glass substrate can be used. Step of forming lower clad layer This is a step of forming the lower clad layer 13 on the surface of the prepared substrate 12. Specifically, as shown in FIG. 2B, the lower layer composition is applied to the surface of the substrate 12 and dried or prebaked to form a lower layer thin film. And
The lower clad layer 13 can be formed by curing the lower layer thin film by irradiating it with radiation. In the step of forming the lower clad layer 13, it is preferable to irradiate the entire surface of the thin film with radiation to cure the entire surface.
Here, as a method for applying the composition for the lower layer, a method such as a spin coating method, a dipping method, a spraying method, a bar coating method, a roll coating method, a curtain coating method, a gravure printing method, a silk screen method, or an inkjet method is used. Can be used. Among these, the spin coating method is more preferable because a lower layer thin film having a particularly uniform thickness can be obtained. Further, in order to appropriately correspond the rheological properties of the composition for the lower layer to the coating method, various leveling agents, thixotropic agents, fillers, organic solvents,
It is preferable to add a surfactant or the like as necessary.
In addition, the lower layer thin film made of the lower layer composition is preferably pre-baked at a temperature of 50 to 200 ° C. for the purpose of removing the organic solvent and the like after coating. The coating method in the formation process of the lower clad layer, the improvement of the rheological properties, and the like are also applicable to the formation process of the core portion and the formation process of the upper clad layer described later. Also, the irradiation dose of the radiation when forming the lower clad layer is not particularly limited, but the wavelength of 200 to
Radiation with 450 nm and illuminance of 1 to 500 mW / cm2
It is preferable to irradiate and expose so that the irradiation amount is 10 to 5,000 mJ / cm 2. The types of radiation to be applied here include visible light, ultraviolet rays, infrared rays, and X rays.
Rays, α rays, β rays, γ rays and the like can be used, but ultraviolet rays are particularly preferable. As a radiation (ultraviolet) irradiation device, for example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, an excimer lamp, or the like is preferably used. Further, after the exposure, further heat treatment (hereinafter referred to as "post bake") is performed so that the entire surface of the coating film is sufficiently cured.
Say. ) Is preferably performed. This heating condition varies depending on the composition of the radiation curable resin composition, the type of additives, etc., but is usually 30 to 400 ° C., preferably 50 to 400 ° C.
The heating conditions may be 300 ° C. and 5 minutes to 72 hours, for example. The radiation dose, type, radiation (ultraviolet) irradiating device, and the like in the lower clad layer forming step are also applicable to the core portion forming step and the upper clad layer forming step, which will be described later.

Formation of Core Portion Next, as shown in FIG. 2C, a core composition is applied to the lower clad layer 13 and dried or further prebaked to form a core thin film 14. After that, Figure 2
As shown in (d), with respect to the upper surface of the core thin film 14,
It is preferable to irradiate the radiation 16 according to a predetermined pattern, for example, through a photomask 19 having a predetermined line pattern. As a result, only the portion irradiated with the radiation is cured, and thus the uncured portion other than that is removed by development, so that the patterned curing on the lower cladding layer 13 is performed as shown in FIG. The core portion 15 made of a film can be formed. Further, the irradiation of the radiation 16 to the core thin film 14 for forming the core portion 15 is performed by the photomask 1 having a predetermined pattern.
9, the unexposed portion is developed with a developing solution to remove the uncured unnecessary portion, thereby forming the core portion 15. As described above, the method of irradiating the radiation according to the predetermined pattern is not limited to the method of using the photomask including the radiation transmitting portion and the radiation non-transmitting portion, and examples thereof include the following methods a to c. a. A method utilizing electro-optically forming means for forming a mask image consisting of a radiation transmitting region and a radiation opaque region according to a predetermined pattern, using the same principle as that of a liquid crystal display device. b. Using a light guide member that bundles many optical fibers,
A method of irradiating radiation through an optical fiber corresponding to a predetermined pattern in the light guide member.

C. A method of irradiating a radiation curable composition while scanning laser light or converging radiation obtained by a condensing optical system such as a lens and a mirror. After the exposure, heat treatment may be performed to accelerate the curing of the exposed portion. The heating condition is usually 30 to 200 ° C., preferably 50 to 150 ° C., though it varies depending on the composition of the radiation curable composition, the type of additives and the like. In this way, the thin film which is pattern-exposed according to a predetermined pattern and selectively cured can be developed by utilizing the difference in solubility between the cured portion and the uncured portion. Therefore, after the pattern exposure, by removing the uncured portion and leaving the cured portion, as a result, the core portion can be formed. Here, as the developing solution, 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]. An alkaline aqueous solution containing an alkali such as -7-undecene or 1,5-diazabicyclo [4.3.0] -5-nonane can be used. Further, when the alkali water-soluble is used, it is preferable that the concentration thereof be a value in the range of usually 0.05 to 25% by weight, preferably 0.1 to 3.0% by weight. It is also preferable to add a suitable amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to such an alkaline aqueous solution and use it as a developing solution. Also, the development time is
It is usually for 30 to 600 seconds, and as the developing method, a known method such as a puddle method, a dipping method and a shower developing method can be adopted. When an organic solvent is used as the developing solution, air-drying is performed as it is. When an alkaline aqueous solution is used, washing with running water is performed, for example, at 30 to 90.
The patterned coating film is formed by removing the moisture on the surface by performing drying for 2 seconds with compressed air, compressed nitrogen or the like.

Then, in order to further cure the patterning portion, a post-baking treatment is performed at a temperature of 30 to 400 ° C. for 5 to 600 minutes by a heating device such as a hot plate or an oven to form a cured core portion. Will be. Formation of Upper Clad Layer Next, the lower clad layer 13 on which the core portion 15 is formed
The composition for the upper layer is applied to the surface of, and dried or prebaked to form a thin film for the upper layer. By irradiating the upper layer thin film with radiation to cure it, the upper clad layer 17 can be formed as shown in FIG. The upper clad layer obtained by irradiation with radiation is preferably post-baked as described above, if necessary. By post-baking, the upper clad layer having excellent hardness and heat resistance can be obtained.

[0029]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples. Each composition is shown in Table 1 and Table 2. [Preparation of Radiation-Curable Composition] Preparation Example 1 of Copolymer (A) After a flask equipped with a dry ice / methanol reflux was replaced with nitrogen, 2,2′-azobisisobutyronitrile was used as a polymerization initiator. And 1.3 g of ethyl lactate as an organic solvent were charged, and the mixture was stirred until the polymerization initiator was dissolved. Subsequently, 6.7 g of methacrylic acid, 15.7 g of dicyclopentanyl methacrylate and 9.0 of styrene.
After charging g and 13.5 g of n-butyl acrylate, gentle stirring was started. After that, increase the temperature of the solution to 8
The temperature was raised to 0 ° C., and polymerization was carried out at this temperature for 5 hours. Thereafter, 10.6 g of 3,4-epoxycyclohexylmethyl acrylate, 0.7 g of tetrabutylammonium bromide and 0.1 g of p-methoxyphenol were added to the obtained solution.
g, and stirred at 80 ° C. for 8 hours to add an epoxy group to a part of the carboxyl group in the polymer,
A polymer solution having an acrylic group on the side chain was obtained. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This redissolving-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-1.

Preparation Example 2 of Copolymer (A) After replacing a flask equipped with a dry ice / methanol reflux with nitrogen, 0.4 g of 2,2'-azobisdimethylvaleronitrile as a polymerization initiator and an organic solvent were used. Then, 59.8 g of ethyl lactate was charged and stirred until the polymerization initiator was dissolved. Subsequently, 8.0 g of methacrylic acid, 10.0 g of dicyclopentanyl methacrylate, 13.9 g of methyl methacrylate, and 8.0 g of n-butyl acrylate were charged, and then gently stirring was started. Then, the temperature of the solution was raised to 70 ° C., and polymerization was carried out at this temperature for 5 hours. Then, 31.9 g of 3,4-epoxycyclohexylmethyl acrylate, 2.2 g of tetrabutylammonium bromide, and 0.1 g of p-methoxyphenol were added to the obtained solution, and the mixture was stirred at 80 ° C. for 8 hours to give a polymer in the polymer. An epoxy group was added to a part of the carboxyl group of to obtain a polymer solution having an acrylic group in the side chain. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This re-dissolution-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-2.

Preparation Example 3 of Copolymer (A) After a flask equipped with a dry ice / methanol reflux was replaced with nitrogen, 1.3 g of 2,2'-azobisisobutyronitrile was used as a polymerization initiator. Charge 53.8 g of diethylene glycol dimethyl ether as a solvent,
The mixture was stirred until the polymerization initiator was dissolved. Subsequently, 6.7 g of methacrylic acid and 15.7 of glycidyl methacrylate.
g, styrene 9.0 g, and n-butyl acrylate 13.5 g were charged, and then gently stirring was started. Then, the temperature of the solution was raised to 80 ° C., and polymerization was carried out at this temperature for 5 hours. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This redissolving-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-3.

Preparation Example 4 of Copolymer (A) After replacing a flask equipped with a dry ice / methanol reflux with nitrogen, 1.3 g of 2,2′-azobisisobutyronitrile was used as a polymerization initiator. 53.8 g of ethyl lactate was charged as an organic solvent, and the mixture was stirred until the polymerization initiator was dissolved. Subsequently, 6.7 g of methacrylic acid and 15.7 of (2-ethyl-2-oxetanyl) methyl acrylate.
g, styrene 9.0 g, and n-butyl acrylate 13.5 g were charged, and then gently stirring was started. Then, the temperature of the solution was raised to 80 ° C., and polymerization was carried out at this temperature for 5 hours. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This redissolution-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-4.

Preparation Example 5 of Copolymer (A) After replacing a flask equipped with a dry ice / methanol reflux with nitrogen, 1.3 g of 2,2'-azobisisobutyronitrile as a polymerization initiator, an organic solvent was added. 53.8 g of ethyl lactate was charged as a solvent, and the mixture was stirred until the polymerization initiator was dissolved. Subsequently, 6.7 g of methacrylic acid, 15.7 g of dicyclopentanyl methacrylate and 9.0 of styrene.
After charging g and 13.5 g of n-butyl acrylate, gentle stirring was started. After that, increase the temperature of the solution to 8
The temperature was raised to 0 ° C., and polymerization was carried out at this temperature for 5 hours. Then, 31.9 g of 3,4-epoxycyclohexylmethyl acrylate, 2.2 g of tetrabutylammonium bromide, and 0.1 g of p-methoxyphenol were added to the obtained solution.
g, and stirred at 80 ° C. for 8 hours to add an epoxy group to all of the carboxyl groups in the polymer,
A polymer solution having an acrylic group on the side chain was obtained. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This re-dissolution-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-5.

Preparation Example 6 of Copolymer (A) After a flask equipped with a dry ice / methanol reflux was replaced with nitrogen, 1.3 g of 2,2'-azobisisobutyronitrile was used as a polymerization initiator. 53.8 g of ethyl lactate was charged as a solvent, and the mixture was stirred until the polymerization initiator was dissolved. Subsequently, 6.7 g of methacrylic acid, 15.7 g of dicyclopentanyl methacrylate and 9.0 of styrene.
After charging g and 13.5 g of n-butyl acrylate, gentle stirring was started. After that, increase the temperature of the solution to 8
The temperature was raised to 0 ° C., and polymerization was carried out at this temperature for 5 hours. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This redissolving-coagulation operation was performed three times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-6.

Preparation Example 7 of Copolymer (A) After a flask equipped with a dry ice / methanol reflux was replaced with nitrogen, 0.4 g of 2,2′-azobisdimethylvaleronitrile as a polymerization initiator and an organic solvent were used. Then, 59.8 g of ethyl lactate was charged and stirred until the polymerization initiator was dissolved. Subsequently, 8.0 g of methacrylic acid, 10.0 g of dicyclopentanyl methacrylate, 13.9 g of methyl methacrylate, and 8.0 g of n-butyl acrylate were charged, and then gently stirring was started. Then, the temperature of the solution was raised to 70 ° C., and polymerization was carried out at this temperature for 5 hours. Then, the reaction product was dropped into a large amount of hexane to solidify the reaction product. Further, the coagulated product was redissolved in tetrahydrofuran of the same weight and coagulated again with a large amount of hexane. This redissolving-coagulation operation was performed 3 times in total, and the obtained coagulated product was vacuum dried at 40 ° C. for 48 hours to obtain the target copolymer A-7.

Preparation of Radiation Curable Composition J-1 A polyfunctional acrylate (M8100, manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition, was added to 33.0 parts by weight of the above-mentioned copolymer A-1. 9 parts by weight, 6.6 parts by weight of trimethylolpropane triacrylate, and Irgcure. Radiation curable composition J-1 was obtained by adding 1.0 part by weight of 369 (manufactured by Ciba Specialty Chemicals) and 49.5 parts by weight of ethyl lactate and mixing them uniformly.

Preparation of radiation-curable composition J-2 17. To 28.3 parts by weight of the above-mentioned copolymer A-2, a polyfunctional acrylate (M8100 manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition, was used. 0 parts by weight, 11.3 parts by weight of trimethylolpropane triacrylate, and Irgcure. Radiation curable composition J-2 was obtained by adding 1.0 part by weight of 369 (manufactured by Ciba Specialty Chemicals) and 42.5 parts by weight of ethyl lactate and mixing them uniformly.

Preparation of Radiation Curable Composition J-3 A polyfunctional oxirane compound (Eporide GT301 manufactured by Daicel Chemical Co., Ltd.), which is a polymerization-reactive composition, was added to 33.0 parts by weight of the above-mentioned copolymer A-3. 16.5 parts by weight,
A radiation curable composition J-3 was obtained by adding 1.0 part by weight of a radiation cationic polymerization initiator SP170 (manufactured by Asahi Denka Co., Ltd.) and 49.5 parts by weight of diethylene glycol dimethyl ether, and mixing them uniformly. .

Preparation of Radiation Curable Composition J-4 A polyfunctional oxirane compound (Eporide GT301 manufactured by Daicel Chemical Co., Ltd.), which is a polymerization-reactive composition, was added to 33.0 parts by weight of the above-mentioned copolymer A-4. 16.5 parts by weight,
A radiation curable composition J was prepared by adding 1.0 part by weight of SP170 (manufactured by Asahi Denka Co., Ltd.), which is a radiation cationic polymerization initiator, and 49.5 parts by weight of ethyl lactate, and mixing them uniformly.
-3 was obtained.

Preparation of radiation-curable composition J-5: 13.5 parts by weight of a polymerization-reactive composition, pentaerythritol triacrylate, was added to 35.0 parts by weight of the above-described copolymer A-1 and radiation-radical-polymerized. The initiator Irgcure. A radiation curable composition J-5 was obtained by adding 3.0 parts by weight of 369 (manufactured by Ciba Specialty Chemicals) and 48.5 parts by weight of ethyl lactate and mixing them uniformly.

Preparation of Radiation-Curable Composition J-6 To 33.0 parts by weight of the above-mentioned copolymer A-1 was added a polyfunctional acrylate (M8100 manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition. 9 parts by weight, 6.6 parts by weight of trimethylolpropane triacrylate, and Irgcure. 819 (manufactured by Ciba Specialty Chemicals) and 1.05 parts by weight of ethyl lactate were added and uniformly mixed to obtain a radiation curable composition J-6.

Preparation of Radiation Curable Composition J-7 (Comparison
Example) With respect to 33.0 parts by weight of the above-mentioned copolymer A-5, 9.9 parts by weight of a polyfunctional acrylate (M8100 manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition, and 6 parts of trimethylolpropane triacrylate were used. .6 parts by weight, Irgcure. Radiation curable composition J-7 was obtained by adding 1.0 part by weight of 369 (manufactured by Ciba Specialty Chemicals) and 49.5 parts by weight of ethyl lactate and mixing them uniformly.

Preparation of radiation curable composition J-8 (comparison
Example) With respect to 33.0 parts by weight of the above-mentioned copolymer A-6, 9.9 parts by weight of a polyfunctional acrylate (M8100 manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition, and 6 parts of trimethylolpropane triacrylate were used. .6 parts by weight, Irgcure. Radiation curable composition J-8 was obtained by adding 1.0 part by weight of 369 (manufactured by Ciba Specialty Chemicals) and 49.5 parts by weight of ethyl lactate and mixing them uniformly. It was

Preparation of Radiation Curable Composition J-9 (Comparison
Example) With respect to 28.3 parts by weight of the above-mentioned copolymer A-7, 17.0 parts by weight of a polyfunctional acrylate (M8100 manufactured by Toagosei Co., Ltd.), which is a polymerization-reactive composition, and 11 parts of trimethylolpropane triacrylate were used. .3 parts by weight, a radiation radical polymerization initiator Irgcure. Radiation curable composition J-9 was obtained by adding 1.0 part by weight of 369 (manufactured by Ciba Specialty Chemicals) and 42.5 parts by weight of ethyl lactate and mixing them uniformly.

Example 1 (1) Formation of Optical Waveguide Formation of Lower Clad Layer The radiation curable composition J-2 was applied onto the surface of a silicon substrate.
Apply with a spin coater and 100 using a hot plate
Prebaking was performed under the conditions of 10 ° C. and 10 minutes. Then, a coating film composed of the radiation curable composition J-2 was coated with a wavelength of 365 nm,
Ultraviolet rays having an illuminance of 20 mW / cm @ 2 were irradiated for 30 seconds to cure the radiation. Then, this cured film is post-baked under the condition of 150 ° C. for 1 hour to obtain a thickness of 50 μm.
m of the lower clad layer. Formation of Core Part Next, a radiation curable composition J-1 was coated on the lower clad layer with a spin coater, and prebaked at 100 ° C. for 10 minutes using a hot plate. afterwards,
A 50 μm-thick coating film made of the radiation-curable composition J-1 is irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 20 mW / cm 2 for 30 seconds through a photomask having a line-shaped pattern having a width of 50 μm to form a coating film. Was radiation cured.
Then, 1.0% of the substrate having the radiation-cured coating film
Tetramethylammonium hydroxide aqueous solution (TMA
The unexposed portion of the coating film was dissolved by immersing it in a developing solution containing H). Then, post-baking was performed at 150 ° C. for 1 hour to form a core portion having a line-shaped pattern with a width of 50 μm. Formation of Upper Clad Layer Next, the radiation curable composition J-2 was applied on the upper surface of the lower clad layer having a core portion by a spin coater, and prebaked at 100 ° C. for 10 minutes using a hot plate. Then, the coating film made of the radiation curable composition J-2 was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 20 mW / cm 2 for 30 seconds to form an upper clad layer having a thickness of 50 μm.

[Examples 2 to 5, Comparative Examples 1 and 2] Instead of using the composition described in Example 1 for the lower clad layer, the core portion and the upper clad layer, the composition shown in Table 3 was used. An optical waveguide was formed by the same method as all the methods described above.

(2) Accuracy of optical waveguide shape Core shape designed by the above method (height 50 μm ×
With respect to the line width of 50 μm), the case where the core height and the core width are both 50 ± 5 μm is defined as “◯”, and the case where the shape is more than or equal to the following is defined as “x”. (3) Evaluation of Transmission Loss of Optical Waveguide The optical waveguide including the lower clad layer, the core portion and the upper clad layer thus obtained has a wavelength of 85
Light of 0 nm was made incident from one end. Then, by measuring the amount of light emitted from the other end, the waveguide loss per unit length was obtained by the cutback method. (4) Solvent resistance Regarding the optical waveguide comprising the lower clad layer, the core part and the upper clad layer thus obtained, the coating film does not come off from the substrate after being immersed in tetrahydrofuran (THF) at room temperature for 24 hours. The case was designated as "○", and the case of peeling was designated as "x". The results of the above measurements are shown in Table 2.
In Comparative Example 1, when the J-7 core portion was formed, the target core shape could not be obtained because the unexposed portion did not dissolve in the alkali developing solution during alkali development. Therefore, the transmission loss of the optical waveguide using the same showed a value of 1 dB / cm or more. Further, in Comparative Example 2, the target shape could not be obtained because partial dissolution occurred in the cured part after the alkali development. Therefore, the loss of the optical waveguide using it is 1 dB / c.
A value of m or more was shown.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

As described above, by using the radiation-curable composition of the present invention, it is extremely easy and in a short time.
It has become possible to mold optical waveguides with high precision. Further, the optical waveguide formed of the radiation curable composition of the present invention was able to obtain low transmission loss. As described above, according to the method for manufacturing an optical waveguide of the present invention, the optical waveguide can be efficiently manufactured.

[0052]

[Brief description of drawings]

FIG. 1 is a sectional view of an optical waveguide of the present invention.

2A to 2E are partial process diagrams of a method for manufacturing an optical waveguide.

[0053]

[Explanation of symbols]

10 Optical waveguide 12 substrates 13 Lower clad layer 14 core thin film 15 core part 16 Radiation 17 Upper clad layer 18 Ridge 19 Photomask

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuichi Eriyama             2-11-21 Tsukiji, Chuo-ku, Tokyo J             Within SRL Co., Ltd. F term (reference) 2H047 KA04 PA02 PA15 PA21 PA22                       PA28 QA02 QA04 QA05 TA36                       TA43                 4J027 AA02 BA19 BA20 BA21 BA26                       CB03 CC03 CD03                 4J036 AB01 AB07 AD01 AD08 AD21                       AF01 AF06 AK08 AK09 AK11                       AK19 DB17 FB18 GA01 HA01                       JA15

Claims (6)

[Claims] 1. A polymer (A) having a structure represented by the following general formula (1): [R ¹ , R ² and R ³ are hydrogen or an alkyl group having a carbon chain of 1 to 12, X is a group having a carboxyl group, Y is a group having a polymerizable group, Z is an organic group other than X and Y. There is (B) a compound having two or more polymerizable reactive groups in the molecule and (C) a radiation polymerization initiator, which is a radiation-curable composition for forming an optical waveguide. 2. The radiation-curable composition for forming an optical waveguide according to claim 1, further comprising an organic solvent as the component (D). 3. The radiation curable composition for forming an optical waveguide according to claim 1, wherein the polymerizable reactive group of the component (B) is an ethylenically unsaturated group. 4. An optical waveguide including a lower clad layer, a core portion, and an upper clad layer, wherein the lower clad layer comprises:
An optical waveguide in which at least one of the core portion and the upper clad layer is composed of a cured product of a radiation curable composition containing the following components (A) to (C). (A) A polymer having a structure represented by the following general formula (1): [R ¹ , R ² and R ³ are hydrogen or an alkyl group having a carbon chain of 1 to 12, X is a group having a carboxyl group, Y is a group having a polymerizable group, Z is an organic group other than X and Y. Yes] (B) compound having two or more polymerizable reactive groups in the molecule (C) radiation polymerization initiator 5. The radiation curable composition for forming the lower clad layer, the core portion and the upper clad layer, wherein the refractive index of the core portion is 0.1% or more higher than that of the clad layer. Item 4. The optical waveguide according to item 4. 6. A method of manufacturing an optical waveguide including a lower cladding layer, a core portion, and an upper cladding layer, the step of forming the lower cladding layer, the step of forming the core portion, and the formation of the upper cladding layer. And a step of
A method for producing an optical waveguide, wherein at least one of these steps is a step of radiation-curing the radiation-curable composition according to claim 1.