JP2005055717A - Photosensitive resin composition for optical waveguide and optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for an optical waveguide which ensures little waveguide loss, is excellent in long-term reliability and can accurately produce the form of the optical waveguide. <P>SOLUTION: The photosensitive resin composition for an optical waveguide contains (A) a polymer having radical-polymerizable functional groups, wherein a number average molecular weight divided by the number of mols of the radical-polymerizable functional groups equals ≥3,000, (B) a (meth)acrylate having formula (1) and/or a specified structure, and (C) a radical photopolymerization initiator. In the formula, R represents -(CH<SB>2</SB>CH<SB>2</SB>O)<SB>n</SB>-, -(CH<SB>2</SB>CH(CH<SB>3</SB>)O)<SB>n</SB>- or -CH<SB>2</SB>CH(OH)CH<SB>2</SB>O- (n is an integer of 0-4); X represents -C(CH<SB>3</SB>)<SB>2</SB>-, -CH<SB>2</SB>-, -O- or -SO<SB>2</SB>-; and Y represents H or halogen. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photosensitive resin composition for an optical waveguide for producing an optical circuit used in the fields of optical communication and optical information processing, and an optical waveguide produced using the composition.

  In the multimedia era, transmission systems that use light as a transmission medium have become public communication networks, LANs (local area networks), and FAs (factory automation) in response to demands for large capacity and high speed information processing in optical communication systems and computers. ), Being used for interconnects between computers, home wiring, and the like. Among the elements constituting this transmission system, the optical waveguide is, for example, an optical device, an optical integrated circuit (OEIC), an optical integrated circuit (optical IC) and the like. Optical waveguides are intensively studied due to the large amount of demand, and in particular, high performance and low cost products are required.

Conventionally known silica optical waveguides and polymer optical waveguides are known as optical waveguides.
Among these, the quartz-based optical waveguide has an advantage that the transmission loss is low, but has a problem in process such as a high processing temperature in the manufacturing process and difficulty in manufacturing a large-area one.
Also, polymer-based optical waveguides have advantages such as ease of processing and wide material design. Therefore, those using polymer materials such as polymethyl methacrylate and polycarbonate have been studied. However, in general, a polymer-based optical waveguide has a problem that heat resistance is poor. Therefore, recently, fluorinated polyimides having excellent heat resistance and transmission loss have been actively studied.

However, when a polymer material is used, when the core portion in the optical waveguide is manufactured, a dry etching process is required as in the case of the silica-based optical waveguide. is there.
Under such circumstances, in recent years, photocurable materials such as epoxy-based ultraviolet curable resins imparted with photolithography properties and optical waveguides using the materials have been proposed (for example, see Patent Document 1).

Japanese Patent Laid-Open No. Hei 6-273631

Conventional polymer-based optical waveguide materials have various problems, that is, the waveguide loss is relatively large in the wavelength range of 650 to 1600 nm used in optical communication or the like, the heat resistance is low, or the effective shrinkage is low. Due to the large size, there are problems such as peeling from the substrate and inability to manufacture with high accuracy, and none of the characteristics required for the optical waveguide are satisfied.
In order to solve this problem, chemical treatments such as fluorination and deuteration substitution of polymers have been studied. However, even when such chemical treatment is performed, various problems, that is, substrate and There are problems such as a decrease in adhesiveness and peeling, a problem in long-term reliability, and a failure to increase the refractive index to a predetermined level when used as a core material.
Accordingly, the present invention provides a photosensitive resin composition for an optical waveguide that has low waveguide loss, is excellent in long-term reliability, and can accurately produce the desired waveguide shape, and a cured product of the composition. It aims at providing the optical waveguide which consists of.

  As a result of intensive studies to solve the above problems, the present inventors have found that a specific polymer having a polymerizable functional group, an aromatic (meth) acrylate having a specific chemical structure, and a radical photopolymerization initiator Is used as a resin composition for forming one or both of the core layer and the cladding layer of the optical waveguide, thereby providing a suitable refractive index to each layer. On the other hand, the present invention has been completed by finding that an optical waveguide with low waveguide loss, excellent long-term reliability, and excellent waveguide shape accuracy can be obtained.

（式中、Ｒは−（ＣＨ_２ＣＨ_２Ｏ）_ｎ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｎ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｘは−Ｃ（ＣＨ_３）_２−、−ＣＨ_２−、−Ｏ−または−ＳＯ_２−；Ｙは水素原子またはハロゲン原子を表す。ただし、ｎは０〜４の整数を表す。）

（式中、Ｒは−（ＣＨ_２ＣＨ_２Ｏ）_ｎ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｎ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｙは水素原子、ハロゲン原子、Ｐｈ−Ｃ（ＣＨ_３）_２−、Ｐｈ−、または炭素数１〜２０のアルキル基を表す。ただし、ｎは０〜４の整数、Ｐｈはフェニル基を表す。） That is, the photosensitive resin composition for forming an optical waveguide of the present invention (Claim 1) is (A) a polymer having a radical polymerizable functional group, and the number average molecular weight is the number of moles of the radical polymerizable functional group. A polymer having a value of 3,000 or more, (B) a (meth) acrylate having a structure represented by the following formula (1) and / or the following formula (2), and (C) a radical photopolymerization initiator. As a constituent component.

Wherein R is — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; X is —C (CH ₃ ) ₂ —, —CH ₂ —, —O— or —SO ₂ —; Y represents a hydrogen atom or a halogen atom, where n represents an integer of 0 to 4.)

(Wherein R represents — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; Y represents a hydrogen atom, halogen) Atom, Ph—C (CH ₃ ) ₂ —, Ph—, or an alkyl group having 1 to 20 carbon atoms, where n is an integer of 0 to 4 and Ph represents a phenyl group.

  The photosensitive resin composition for forming an optical waveguide of the present invention is excellent in patterning property at the time of curing, and has excellent transmission characteristics (low waveguide loss), excellent long-term reliability, etc. when an optical waveguide is formed. Therefore, it can be suitably used as an optical waveguide forming material.

Hereinafter, the present invention will be described in detail.
The resin composition of the present invention contains components (A) to (C) described below as constituent components.
The component (A) constituting the resin composition of the present invention is a polymer having a radical polymerizable functional group, and a value obtained by dividing the number average molecular weight by the number of moles of the radical polymerizable functional group is 3,000 or more. It is a polymer.
The radical polymerizable functional group in the component (A) may be any of a functional group capable of addition polymerization, cyclopolymerization, isomerization polymerization, ring-opening polymerization, polyaddition, and condensation. Preferred are functional groups capable of addition polymerization or ring-opening polymerization, such as those having an unsaturated double bond such as (meth) acryloyl group, vinyl group, vinyl ether, oxirane, oxetane, oxolane, thiirane, cyclohexene oxide, etc. And those having a cyclic reactive group.
The polymer structure of component (A) is not particularly limited, but the glass transition temperature (Tg) of component (A) is preferably 50 ° C. or higher from the viewpoint of improving the heat resistance of the waveguide. Among polymers having a Tg of 50 ° C. or higher, polymers having a main structure of polystyrene or polymethyl methacrylate as shown in the following formulas (3) and (4) are improved in heat resistance and transparency (low loss). Is particularly preferred.

（式中、Ｒは水素原子またはメチル基；ｎは２８以上の整数を表す。）

（式中、Ｒは水素原子またはメチル基；ｎは３０以上の整数を表す。）

(In the formula, R represents a hydrogen atom or a methyl group; n represents an integer of 28 or more.)

(In the formula, R represents a hydrogen atom or a methyl group; n represents an integer of 30 or more.)

The number average molecular weight of the component (A) polymer is preferably 3,000 or more. If the number average molecular weight is less than 3,000, the target waveguide shape may not be obtained, or the waveguide may be peeled off from the substrate.
The upper limit of the number average molecular weight of the component (A) polymer is not particularly limited, but is preferably 50,000 or less. When the number average molecular weight exceeds 50,000, the solubility in the resin composition is lowered, and it is difficult to obtain a uniform resin composition.
The content of the radically polymerizable functional group in the polymer of component (A) is 3,000 or more, preferably 5,000, as a value obtained by dividing the number average molecular weight of the polymer by the number of moles of the radically polymerizable functional group. That's it. When the value is less than 3,000, the curing shrinkage of the photocured cured product is increased, and the accuracy of the shape of the optical waveguide may be lowered.
The radically polymerizable functional group is preferably at the terminal in the chemical structure of the polymer of component (A). Examples of preferred radical polymerizable functional groups include (meth) acryloyl groups. As a commercial item of the polymer of a component (A), AA-6, AS-6 (above, Toagosei Co., Ltd. product) etc. are mentioned.
In addition, the polymer of a component (A) may be used individually by 1 type, and may use 2 or more types together.

  The weight ratio of the component (A) component in the resin composition of the present invention is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the total amount of the composition including the optional components. If the weight ratio is less than 5% by weight, the target waveguide shape may not be obtained, or the waveguide may be peeled off from the substrate. When this weight ratio exceeds 50 weight%, the viscosity of a resin composition may increase and a problem may arise in coating property.

（式中、Ｒは−（ＣＨ_２ＣＨ_２Ｏ）_ｎ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｎ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｘは−Ｃ（ＣＨ_３）_２−、−ＣＨ_２−、−Ｏ−または−ＳＯ_２−；Ｙは水素原子またはハロゲン原子を表す。ただし、ｎは０〜４の整数を表す。）

（式中、Ｒは−（ＣＨ_２ＣＨ_２Ｏ）_ｎ−、−（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｎ−、または−ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ−；Ｙは水素原子、ハロゲン原子、Ｐｈ−Ｃ（ＣＨ_３）_２−、Ｐｈ−、または炭素数１〜２０のアルキル基を表す。ただし、ｎは０〜４の整数、Ｐｈはフェニル基を表す。） Component (B) constituting the resin composition of the present invention is a (meth) acrylate having a structure represented by the following formula (1) and / or the following formula (2). When (meth) acrylate having a structure other than the structures represented by the following formulas (1) and (2) is used, the physical properties of the cured product, particularly the predetermined refractive index required for the use of the optical waveguide is obtained. May become difficult and may cause problems in heat resistance.

Wherein R is — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; X is —C (CH ₃ ) ₂ —, —CH ₂ —, —O— or —SO ₂ —; Y represents a hydrogen atom or a halogen atom, where n represents an integer of 0 to 4.)

(Wherein R represents — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; Y represents a hydrogen atom, halogen) Atom, Ph—C (CH ₃ ) ₂ —, Ph—, or an alkyl group having 1 to 20 carbon atoms, where n is an integer of 0 to 4 and Ph represents a phenyl group.

Among these, from the viewpoint of improving heat resistance, di (meth) acrylate having a structure represented by the formula (1) is preferable.
Specific examples of the di (meth) acrylate having the structure represented by the formula (1) include, for example, ethylene oxide-added bisphenol A (meth) acrylate, ethylene oxide-added tetrabromobisphenol A (meth) acrylate, propylene oxide Addition bisphenol A (meth) acrylic acid ester, propylene oxide addition tetrabromobisphenol A (meth) acrylic acid ester, bisphenol A epoxy (meth) obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid Tetrabromobisphenol A epoxy (meth) acrylate, bisphenol F obtained by epoxy ring-opening reaction of acrylate, tetrabromobisphenol A diglycidyl ether and (meth) acrylic acid Bisphenol F epoxy (meth) acrylate obtained by epoxy ring-opening reaction between glycidyl ether and (meth) acrylic acid, tetrabromobisphenol obtained by epoxy ring-opening reaction between tetrabromobisphenol F diglycidyl ether and (meth) acrylic acid F epoxy (meth) acrylate etc. are mentioned.

  Among them, ethylene oxide-added bisphenol A (meth) acrylic acid ester, ethylene oxide-added tetrabromobisphenol A (meth) acrylic acid ester, bisphenol A epoxy obtained by epoxy ring-opening reaction of bisphenol A diglycidyl ether and (meth) acrylic acid ( Particularly preferred are (meth) acrylates, tetrabromobisphenol A epoxy (meth) acrylates, and the like.

  Examples of commercially available di (meth) acrylates having a structure represented by the formula (1) include, for example, Biscote # 700, # 540 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-208, M- 210 (above, manufactured by Toagosei Co., Ltd.), NK ester BPE-100, BPE-200, BPE-500, A-BPE-4 (above, manufactured by Shin-Nakamura Chemical Co., Ltd.), light ester BP-4EA, BP -4PA, epoxy ester 3002M, 3002A, 3000M, 3000A (manufactured by Kyoeisha Chemical Co., Ltd.), KAYARAD R-551, R-712 (manufactured by Nippon Kayaku Co., Ltd.), BPE-4, BPE-10 BR-42M (Daiichi Kogyo Seiyaku Co., Ltd.), Lipoxy VR-77, VR-60, VR-90, SP-1506, SP-1506, SP-150 , SP-1509, SP-1563 (or more, Showa High Polymer Co., Ltd.), NEOPOL V779, NEOPOL V779MA (manufactured by Japan U-PICA Co., Ltd.), and the like.

  Specific examples of the mono (meth) acrylate having a structure represented by the formula (2) include, for example, phenoxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, 4-phenylphenoxyethyl (meth) acrylate, 3- (2-phenylphenyl) -2-hydroxypropyl (meth) acrylate P-cumylphenol reacted with ethylene oxide, (meth) acrylate, 2-bromophenoxyethyl (meth) acrylate, 4-bromophenoxyethyl (meth) acrylate, 2,4-dibromophenoxyethyl (meth) acrylate , 2,6-dibromo phenoxyethyl (meth) acrylate, 2,4,6-bromophenyl (meth) acrylate, 2,4,6-tribromophenoxyethyl (meth) acrylate.

  Among them, phenoxyethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, (meth) acrylate of p-cumylphenol reacted with ethylene oxide, 2,4,6-tribromophenoxyethyl (meth) acrylate, Particularly preferably used.

  Examples of commercially available mono (meth) acrylates having a structure represented by the formula (2) include, for example, Aronix M113, M110, M101, M102, M5700, TO-1317 (above, manufactured by Toagosei Co., Ltd.), and Biscoat. # 192, # 193, # 220, 3BM (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), NK ester AMP-10G, AMP-20G (above, made by Shin-Nakamura Chemical Co., Ltd.), light acrylate PO-A , P-200A, epoxy ester M-600A (above, manufactured by Kyoeisha Chemical Co., Ltd.), PHE, CEA, PHE-2, BR-30, BR-31, BR-31M, BR-32 (above, Daiichi Kogyo) Pharmaceutical Co., Ltd.).

The weight ratio of the component (B) in the resin composition of the present invention is preferably 5% by weight or more, more preferably 10% by weight or more, and particularly preferably 15% by weight or more with respect to the total amount of the composition including optional components. It is. When the weight ratio is 15% by weight or more, when the resin composition of the present invention is used for the core portion of the optical waveguide, a higher refractive index and a lower waveguide loss can be obtained.
Although the upper limit of the weight ratio of a component (B) is not specifically limited, Preferably it is 80 weight% or less, More preferably, it is 70 weight% or less. If the weight ratio exceeds 80% by weight, there are disadvantages such as a deterioration of the shape of the waveguide and a problem in long-term reliability.

Component (C) constituting the resin composition of the present invention is a radical photopolymerization initiator.
Specific examples of component (C) include, for example, acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenyl. Amine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropyl Phenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthio Sandone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Examples thereof include bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

Examples of commercially available components (C) include Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI 1700, CGI 1750, CGI 11850, CG 24-61, Darocurl 116, 1173 (above, Ciba Specialty Chemicals ( Co., Ltd.), Lucirin LR8728 (manufactured by BASF), Ubekrill P36 (manufactured by UCB) and the like.
In addition, a component (C) may be used individually by 1 type, and may use 2 or more types together.

  The weight ratio of the component (C) in the resin composition of the present invention is usually 0.01 to 10% by weight, preferably 0.5 to 7% by weight, based on the total amount of the composition including the optional components. By setting the weight ratio to 10% by weight or less, curing characteristics, transmission characteristics, patterning characteristics, handling characteristics, and the like can be improved. Further, by setting the weight ratio to 0.01% by weight or more, patterning property, mechanical properties of the cured product, and the like can be improved, and a decrease in the curing rate can be prevented.

  The photosensitive resin composition for an optical waveguide of the present invention includes, as an optional component, a monomer (E) containing a (meth) acryloyl group or a vinyl group that is different from the component (A) and the component (B) (hereinafter referred to as “unsatisfied” Saturated monomer ") can be used. The unsaturated monomer used in the present invention includes a monofunctional unsaturated monomer and a polyfunctional unsaturated monomer.

  Specific examples of the monofunctional unsaturated monomer include, for example, vinyl monomers such as N-vinylpyrrolidone, N-vinylcaprolactam, vinylimidazole, and vinylpyridine; isobornyl (meth) acrylate, bornyl (meth) acrylate, 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, 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, methoxy Polyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (Meth) 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 formula (5), ( 6)

（式中、Ｒ^１は水素原子またはメチル基；Ｒ^２は炭素数２〜８のアルキレン基；ｎは１〜８の整数を表す。）、

（式中、Ｒ^１およびＲ^３は各々独立して水素原子またはメチル基；Ｒ^２は炭素数２〜８のアルキレン基；ｎは１〜８の整数を表す。）
で表される単官能モノマー等が挙げられる。

(Wherein R ¹ represents a hydrogen atom or a methyl group; R ² represents an alkylene group having 2 to 8 carbon atoms; n represents an integer of 1 to 8).

(Wherein R ¹ and R ³ each independently represent a hydrogen atom or a methyl group; R ² represents an alkylene group having 2 to 8 carbon atoms; n represents an integer of 1 to 8)
And monofunctional monomers represented by

  The polyfunctional unsaturated monomer used in the present invention includes bifunctional and trifunctional or higher unsaturated monomers. Here, the bifunctional unsaturated monomer is an unsaturated monomer having two (meth) acryloyl groups or vinyl groups in the molecule, and specific examples thereof include, for example, 1,4-butanediol diacrylate, Polyalkylene glycol diacrylates such as 1,6-hexanediol diacrylate, alkyldiol diacrylates such as 1,9-nonanediol diacrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol diacrylate, and tripropylene glycol diacrylate , Neopentyl glycol di (meth) acrylate, tricyclodecane methanol diacrylate and the like.

Examples of the trifunctional or higher unsaturated monomer, that is, (meth) acrylate having three or more (meth) acryloyl groups include (meth) acrylates of trihydric or higher polyhydric alcohols. Specific examples of the (meth) acrylate include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, and tris (2-acryloyloxyethyl) isocyanate. Examples thereof include nurate and pentaerythritol polyacrylate.
These unsaturated monomers can be used alone or in combination of two or more.

  The resin composition of the present invention further includes an oligomer or polymer such as polyurethane (meth) acrylate, polyester (meth) acrylate, polyepoxy (meth) acrylate, or unsaturated divinyl ether such as vinyl ether other than (meth) acrylate. Monomers, oligomers, and polymers having a cyclic reactive group such as those having a heavy bond, oxirane, oxetane, oxolane, thiirane, and cyclohexene oxide may be blended.

A photosensitizer can be further blended in the resin composition of the present invention.
Specific examples of the photosensitizer include, for example, triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethyl. Examples thereof include isoamyl aminobenzoate.
Specific examples of commercially available photosensitizers include, for example, Ubekrill P102, 103, 104, 105 (above, manufactured by UCB).

  In the present invention, various additives other than the above-mentioned components include, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, coating surface improvers, thermal polymerization inhibitors, leveling agents, and surface active agents. An agent, a colorant, a storage stabilizer, a plasticizer, a lubricant, a solvent, a filler, an antiaging agent, a wettability improving agent, a release agent, and the like can be blended as necessary.

Here, as a commercially available antioxidant, for example, Irganox 1010, 1035, 1076, 1222 (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), Antigen P, 3C, FR, GA-80 (Sumitomo Chemical ( Etc.).
Examples of commercially available ultraviolet absorbers include Tinuvin P, 234, 320, 326, 327, 328, 329, 213 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Seesorb 102, 103, 110, 501, 202. 712, 704 (manufactured by Sipro Kasei Co., Ltd.).

Commercially available light stabilizers include, for example, Tinuvin 292, 144, 622LD (manufactured by Ciba Specialty Chemicals Co., Ltd.), Sanol LS770 (manufactured by Sankyo Co., Ltd.), Sumisorb TM-061 (Sumitomo Chemical ( Etc.).
Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like. Examples of commercially available products include SH6062, 6030 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), KBE903, 603, 403 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

Examples of the coating surface improving agent include silicone additives such as dimethylsiloxane polyether. Commercially available products include DC-57, DC-190 (above, manufactured by Dow Corning), SH-28PA, SH-29PA, SH-30PA, SH-190 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.) , KF351, KF352, KF353, KF354 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), L-700, L-7002, L-7500, FK-024-90 (above, made by Nihon Unicar Co., Ltd.) It is done.
As a commercial product of a mold release agent, PRISURF A208F (Daiichi Kogyo Seiyaku Co., Ltd. product) etc. are mentioned.

  The resin composition of the present invention can be produced by mixing the above components by a conventional method. The viscosity of the resin composition of the present invention thus prepared is usually 50 to 20,000 cp / 25 ° C., preferably 100 to 10,000 cp / 25 ° C., more preferably 200 to 5,000. If the viscosity is too high, coating unevenness and undulation will occur when the resin composition is applied to the substrate, or patterning properties will deteriorate when the core layer is formed, and the desired shape will not be obtained. On the other hand, even if the viscosity is too low, it is difficult to obtain the target film thickness and the patterning property may be deteriorated.

The cured product of the resin composition of the present invention obtained by curing with radiation preferably has the following physical properties.
The cure shrinkage of the cured product of the resin composition is preferably 8% or less, and more preferably 7% or less. If the cure shrinkage rate is greater than 8%, peeling from the substrate may occur after the reliability test. Moreover, when this resin composition is used for a core layer, the shape as designed may not be obtained.
When the cured product of the resin composition of the present invention is used as a core layer of an optical waveguide, the refractive index at 25 ° C. and a wavelength of 824 nm is preferably 1.53 or more, and is 1.54 or more. Is more preferable. When the refractive index is less than 1.53, when a waveguide is formed using the resin composition of the present invention for the core layer, good transmission loss may not be obtained.

  The cured product of the resin composition of the present invention preferably has a glass transition temperature of 50 ° C. or higher, and more preferably 80 ° C. or higher. If the temperature is less than 50 ° C., sufficient heat resistance of the optical waveguide may not be ensured. Here, the “glass transition temperature” is defined as the temperature at which the loss tangent at the vibration frequency of 10 Hz shows the maximum value in the resonance type dynamic viscoelasticity measuring apparatus.

Hereinafter, the present invention will be specifically described based on experimental examples. However, the present invention is not limited to these experimental examples (examples), and various modifications can be made within the scope of the claims.
[Examples 1-4, Comparative Examples 1-3]
Each component shown in Table 1 was charged and stirred for 1 hour while controlling the liquid temperature at 50 to 60 ° C. to obtain a liquid curable composition. In Table 1, the unit of addition amount of each component is parts by weight.
<Ingredient>
The components in Table 1 are as follows.
“AS-6”: Macromer AS-6 (manufactured by Toagosei Co., Ltd.); polymer represented by formula (3) (number average molecular weight 6,000, glass transition temperature 100 ° C.)
“AA-6”: Macromer AA-6 (manufactured by Toagosei Co., Ltd.); polymer represented by formula (4) (number average molecular weight 6,000, glass transition temperature 105 ° C.)
“V779”: Neopole V779 (manufactured by Nippon Upica Co., Ltd.)
(Compound name: Tetrabromobisphenol A epoxy acrylate)
“Vis # 700”: Biscote 700 (manufactured by Osaka Organic Industry Co., Ltd.)
(Compound name: Bisphenol A polyethoxydiacrylate)
"BR-31": New Frontier BR31 (Daiichi Kogyo Seiyaku Co., Ltd.)
(Compound name: Tribromophenoxyethyl acrylate)
“IRG184”: Irgacure 184 (Ciba Specialty Chemicals)
(Compound name: 1-hydroxy-cyclohexyl-phenyl ketone)
“TMPTA”: Biscote 295 (Osaka Organic Chemical Co., Ltd.)
(Compound name: Trimethylolpropane triacrylate)
"IBXMA": (Osaka Organic Chemical Co., Ltd.)
(Compound name: Isobornyl methacrylate)
“SA1002”: (Mitsubishi Chemical Corporation)
(Compound name: Tricyclodecane dimethanol diacrylate)
"VP": VP (manufactured by BASF)
(Compound name: N-vinylpyrrolidone)

<Evaluation method>
1. Evaluation of Refractive Index The refractive index at 824 nm was measured by the following method. First, using a spin coater, while adjusting the rotation speed and time, a liquid curable composition was applied on a 4-inch silicon wafer substrate to a thickness of 7 μm to form a resin composition layer, Under a nitrogen atmosphere, 1.0 J / cm ² ultraviolet rays were irradiated from the mask aligner to the resin composition layer to obtain a cured film. Next, the refractive index (824 nm, 25 ° C.) of this cured film was measured using a prism coupler made by Nippon Metricon.

2. Evaluation of glass transition temperature Using an applicator, a resin composition was applied on a glass substrate to a thickness of 60 μm to form a resin composition layer, and then a conveyor UV irradiation device was used under a nitrogen atmosphere. The resin composition layer was irradiated with 1.0 J / cm ² of ultraviolet rays to obtain a cured film. Next, the temperature dependence of the loss tangent of the cured film was measured using a resonance type dynamic viscoelasticity measuring apparatus while applying vibration with a vibration frequency of 10 Hz. The temperature at which the maximum loss tangent was obtained was taken as the glass transition temperature.

3. Evaluation of Curing Shrinkage Ratio The liquid density (D1) of the resin composition at 23 ° C. was measured using a specific gravity bottle. Subsequently, a cured film having a thickness of 120 μm was produced under the production conditions described above, and left for 24 hours in a constant temperature and humidity chamber at 23 ° C. and 50%. Then, it cut | disconnects to a 20 square mm magnitude | size, the weight (W1) of a test piece, and the weight (W2) in distilled water at 25 degreeC are measured, and the following Formula:
Film density = [W1 / (W1-W2)] × 0.9971
From this, the film density (D2) was calculated. Using D1 and D2, the following formula:
Curing shrinkage = [1- (D1 / D2)] × 100
From this, the cure shrinkage rate was calculated.

4). Evaluation of patterning property Using a spin coater, while adjusting the rotation speed and time, a resin composition was applied on a 4-inch silicon wafer substrate to a thickness of 50 μm to form a resin composition layer. Under an air atmosphere, ultraviolet rays of 1.0 J / cm ² were irradiated from the mask aligner to the resin composition layer through a photomask having a straight shape with no branching of 50 μm width. Next, the resin composition layer was developed for 3 minutes using acetone, and then the substrate was heated in an oven set at 70 ° C. for 10 minutes.
When the obtained pattern is observed with an optical microscope and the desired core shape (50 μm ± 1 μm) is obtained, “◎”, when the shape within the range of 50 μm ± 2 μm is obtained, “○”, the shape When the shape is deformed or a shape out of the range of 50 ± 2 μm is obtained, “x” is given.

5). Evaluation of Transmission Loss Adjusting the rotation speed and time using a spin coater, ELC 2500clear (liquid refractive index n _D ²⁵ = 1.52) manufactured by Electro-Lite is 50 μm thick on a 4-inch silicon wafer substrate. After coating as described above, the coating layer was irradiated with 1.0 J / cm ² of ultraviolet light from a mask aligner in an air atmosphere. Next, after applying the resin composition to the substrate to a thickness of 50 μm using a spin coater, 1.0 J / cm ² of ultraviolet light is applied in an air atmosphere to form a photogram having a straight shape with no branching of 50 μm width. The coating layer was irradiated through a mask. After developing the irradiated coating layer for 3 minutes using acetone, the substrate was heated in an oven set at 70 ° C. for 10 minutes. Furthermore, after applying ELC2500clear made by Electro-Lite to a thickness of 50 μm on the substrate, the substrate was irradiated with ultraviolet rays to obtain a channel waveguide having a linear core line.
After the end face of this waveguide was cut by cleavage, light of 850 nm was inserted through a multimode fiber (50 μm diameter), and the waveguide loss was measured by the cutback method. Cutback was performed by measuring four points in steps of 1 cm from a waveguide length of 5 cm. The obtained light intensity was plotted with respect to the waveguide length, and the loss value was calculated from the slope. When the obtained loss value was 0.5 dB / cm or less, “◯” was evaluated, and when the loss value was higher than that, “×” was evaluated.

6). Evaluation of long-term reliability The thermal shock test was implemented with respect to the produced waveguide (waveguide length 10mm). Specifically, the storage temperature of the waveguide was alternately repeated at −40 ° C. and 85 ° C., and the loss after the end of 500 cycles was measured. The loss after the measurement was 1.0 dB or less, “◯”, and the loss increased more than “×”.
The obtained results are shown in Table 1.

From Table 1, the resin compositions (Examples 1 to 4) of the present invention have excellent patterning properties when forming a cured product, and excellent transmission characteristics when an optical waveguide is formed (low waveguide loss). It can also be seen that it has excellent long-term reliability.
On the other hand, in Comparative Example 1, since the component (A) was not included, peeling from the glass substrate occurred in the long-term reliability test, and transmission loss increased. In Comparative Examples 2 and 3, since the component (B) was not included, a sufficient refractive index difference from the cladding layer could not be secured, and the initial transmission loss increased. In Comparative Example 3, the curing shrinkage ratio was large, the accuracy of the waveguide shape was inferior, and peeling from the glass substrate occurred in the long-term reliability test, resulting in a large transmission loss.

Claims (5)

(A) a polymer having a radical polymerizable functional group, wherein the value obtained by dividing the number average molecular weight by the number of moles of the radical polymerizable functional group is 3,000 or more;
(B) A photosensitive resin for optical waveguides, comprising (meth) acrylate having a structure represented by the following formula (1) and / or the following formula (2), and (C) a radical photopolymerization initiator. Resin composition.

Wherein R is — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; X is —C (CH ₃ ) ₂ —, —CH ₂ —, —O— or —SO ₂ —; Y represents a hydrogen atom or a halogen atom, where n represents an integer of 0 to 4.)

(Wherein R represents — (CH ₂ CH ₂ O) _n —, — (CH ₂ CH (CH ₃ ) O) _n —, or —CH ₂ CH (OH) CH ₂ O—; Y represents a hydrogen atom, halogen) Atom, Ph—C (CH ₃ ) ₂ —, Ph—, or an alkyl group having 1 to 20 carbon atoms, where n is an integer of 0 to 4 and Ph represents a phenyl group.   The photosensitive resin composition for an optical waveguide according to claim 1, wherein the radical polymerizable functional group in the polymer of the component (A) is a (meth) acryloyl group. The said component (A) contains the polymer which has a structure represented by following formula (3) and / or following formula (4), The photosensitive resin composition for optical waveguides of Claim 2 characterized by the above-mentioned.

(In the formula, R represents a hydrogen atom or a methyl group; n represents an integer of 28 or more.)

(In the formula, R represents a hydrogen atom or a methyl group; n represents an integer of 30 or more.)   The photosensitive resin composition for an optical waveguide according to any one of claims 1 to 3, wherein the glass transition temperature of the polymer of the component (A) is 50 ° C or higher. It is an optical waveguide which has a core layer and a clad layer formed by laminating on the core layer, and either or both of the core layer and the clad layer are in any one of claims 1 to 4. An optical waveguide comprising a cured product of the resin composition described above.