JP2003128737A - Resin composition, resin composition for optical waveguide and cured product of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for optical waveguide solved of problems caused by solvents and excellent in processability and provide a cured product of the same. SOLUTION: This resin composition comprises a urethane methacrylate compound (A) which is a reaction product of a compound (a) expressed by general formula (1) (wherein R1 expresses H or CH3 ; R2 , R3 , R4 and R5 are the same or different and each expresses H, a halogen or a 1-6C alkyl) with 2-isocyanate- ethyl methacrylate (b) and an ethylenically unsaturated compound (B) except the component (A).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition suitable for an optical waveguide which is excellent in flatness and can be easily processed, which can be used for an optical circuit, an opto-electronic hybrid board, etc.

[0002]

2. Description of the Related Art Quartz is often used as a material for optical waveguides, but it has a problem that it is difficult to fabricate a large area having a high processing temperature. Recently, research on plastic waveguides using polymethylmethacrylate, etc. has progressed from the viewpoint of ease of processing. Even when such a resin is used, the resin is applied to the substrate in a state of being dissolved in a solvent. After that, in order to remove the solvent to form the core portion and the like, the solvent must be removed at an appropriate rate when removing the solvent. When the removal rate is high, bubbles or voids are generated or internal strain is generated. If the removal rate is low,
It had the drawback of taking a long time. When the removal temperature is increased, bubbles or voids may be generated and internal strain may occur due to the difference in coefficient of thermal expansion between the resin and the substrate.
Further, when a solvent-soluble resin is used for the optical waveguide, it is necessary to prevent the resin portion already formed when forming the clad portion and the core portion from dissolving in the solvent. Therefore, it has been necessary to introduce a cross-linking component into the resin or change the resin components in the core and clad portions. Optical transmission loss factors in optical waveguides, intrinsic factors include high frequency of infrared vibration absorption, absorption loss such as ultraviolet absorption due to electronic transition, scattering loss due to Rayleigh scattering due to density / concentration fluctuation, and external factors are transitions. Absorption loss due to metals, OH groups, and other impurities, impurities such as dust and bubbles, scattering loss due to structural irregularities such as core / cladding interface irregularity, core diameter fluctuation, microbending, and orientation birefringence. Regarding Rayleigh scattering, the coexistence of regions having different refractive indices is not preferable, and those exhibiting a microphase-separated structure such as crystalline polymer, block copolymer, or graft copolymer in the optical waveguide are not preferable. Also,
In order to suppress fluctuations in the solid due to thermal motion, a resin that is three-dimensionally cured by ultraviolet rays is desired rather than a linear polymer. Further, peeling at the core / clad interface also causes a transmission loss, so that the clad resin is required to have good adhesion and adhesiveness to the core material. Therefore, it is desired that the core part and the clad part have similar components. The refractive index of the core of the optical waveguide is required to be higher than that of the cladding. It is preferable that the cladding material of a general multimode waveguide has a refractive index difference of 2 to 3% or more of that of the core material. In the case of optical waveguide in a single mode, 0.3% when the cross section of the core part is a square of 8 μm on a side.
Since a clad having a smaller refractive index is required, the accuracy of the refractive index fluctuation of the core material and the clad material used for such a waveguide is required to be 5/1000. Therefore, a core material (refractive index 1.46 to 1.62) capable of controlling the refractive index range (1.45 to 1.60) such as silicon resin, polymethacrylate resin, or polycarbonate resin which is often used as a clad material is desired. Was there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a resin composition for an optical waveguide which is excellent in processability and a cured product thereof.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific urethane methacrylate compound (A) and an ethylenically unsaturated group-containing compound (B) other than the component (A) are used.
The resin composition containing as a main component, the refractive index can be controlled to some extent by changing the composition, these resins have a low viscosity before curing, excellent coating properties such as spin coating, and the core portion of the optical waveguide or It was found that when it is applied to a clad layer, it has excellent light transmittance and extremely excellent flatness, and has completed the present invention. That is, the present invention provides the compound (a) represented by (1) and the general formula (1).

[0005]

[Chemical 2]

(In the formula (1), R ₁ is a hydrogen atom or CH ₃ ,
R ₂ , R ₃ , R ₄ , and R ₅ are the same or different and each represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms) and a reaction product of 2-isocyanate-ethyl methacrylate (b). Urethane methacrylate compound (A) and ethylenically unsaturated group-containing compound (B) other than component (A)
A resin composition comprising: (2), a resin composition according to (1) containing a photopolymerization initiator (C),
(3), which is a resin composition for an optical waveguide (1) or (2)
And a cured product of the resin composition according to any one of (4) and (1) to (3).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition suitable for the optical waveguide of the present invention is a specific urethane methacrylate compound (A).
And an ethylenically unsaturated group-containing compound (B) other than the component (A).

In the present invention, the urethane methacrylate compound (A) using the urethane methacrylate compound (A) is obtained by reacting the compound (a) represented by the general formula (1) with 2-isocyanate-ethyl methacrylate (b). Can be obtained.

Specific examples of the compound (a) represented by the general formula (1) include bis (4-hydroxyethylthiophenyl) sulfide, bis (4-hydroxypropylthiophenyl) sulfide and bis (3-methyl-). 4-hydroxyethylthiophenyl) sulfide, bis (3,5-dimethyl-4-hydroxyethylthiophenyl) sulfide, bis (2,3,5,6-tetramethyl-4-hydroxyethylthiophenyl) sulfide, bis ( 3-hexyl-4-hydroxyethylthiophenyl) sulfide, bis (3,5-dihexyl-4-hydroxyethylthiophenyl) sulfide, bis (3-chloro-4-hydroxyethylthiophenyl) sulfide, bis (2,2
3,5,6-Tetrachloro-4-hydroxyethylthiophenyl) sulfide, bis (3,5-dibromo-4-)
Hydroxyethylthiophenyl) sulfide, bis (3
-Bromo-4-hydroxyethylthiophenyl) sulfide, bis (2,3,5,6-tetrabromo-4-hydroxyethylthiophenyl) sulfide. Preferably,
Examples thereof include bis (4-hydroxyethylthiophenyl) sulfide and bis (2,3,5,6-tetrabromo-4-hydroxyethylthiophenyl) sulfide.

The reaction ratio between the components (a) and (b) is
It is preferable to react 0.5 to 1.1 equivalents of the isocyanate groups in the component (b) with respect to 1 equivalent of the hydroxyl group in the component (a), and it is particularly preferable to react 0.95 to 1.05 equivalents. .

It is preferable to use a reaction catalyst to accelerate the reaction. Specific examples of the reaction catalyst include tin compounds such as dibutyltin dilaurate and di (n-butyl) tin di (2-ethylhexanoate). The amount of the reaction catalyst used is 50 ppm to 1000 pp in the reaction mixture.
m is preferred.

It is preferable to use a reaction solvent, and as the reaction solvent, an organic solvent inert to isocyanate groups and hydroxyl groups can be preferably used. Specific examples of the organic solvent include methyl ethyl ketone, ketones such as cyclohexanone, toluene, aromatic hydrocarbons such as xylene, ethers such as tetrahydrofuran, γ-butyrolactone,
Examples thereof include lactones such as ε-caprolactone and esters such as ethyl acetate, butyl acetate, carbitol acetate, and butyro cellosolve acetate. The reaction temperature is preferably 20 to 100 ° C, particularly preferably 3
It is 0 to 80 ° C.

In the present invention, the ethylenically unsaturated group-containing compound (B) other than the component (A) is used. Specific examples of the component (B) include (meth) acrylate monomers, (meth) acrylate oligomers, maleimide compounds,
Examples thereof include vinyl ether compounds and N-vinyl compounds.

Specific examples of the (meth) acrylate monomers include dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate and tri-. Bromophenyl (meth) acrylate, methoxyphenyl (meth) acrylate, cyanophenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate,
Polyethylene glycol mono (meth) acrylate, glycidyl (meth) acrylate, carbitol (meth)
Monofunctional (meth) acrylates such as acrylates. Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,4-butylene glycol di (Meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol polyethoxydi (meth) Acrylate, neopentyl glycol polypropoxydi (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (or tetra) (meth) acrylate neopentylglyce Di- (meth) acrylate of the ε-caprolactone adduct of trimethylol, tri (meth) acrylate of the ε-caprolactone adduct of trimethylolpropane, tri- or tetra (meth) acrylate of the ε-caprolactone adduct of pentaerythritol, dipenta Erythritol penta or hexa (meth) acrylate, poly (meth) adduct of dipentaerythritol with ε-caprolactone
Acrylate, ditrimethylolpropane tetra (meth) acrylate tetrabromobisphenol A polyethoxydi (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol hexafluoropropyl polyethoxydi (meth) acrylate, hydrogenated bisphenol hexafluoropropyl polyethoxydi ( Examples thereof include polyfunctional (meth) acrylates such as (meth) acrylate.

Specific examples of (meth) acrylate oligomers include polyester (meth) acrylate, urethane (meth) acrylate and epoxy (meth) acrylate.

Specific examples of polyester (meth) acrylates include (poly) ethylene glycol, (poly) propylene glycol, (poly) tetramethylene glycol, (poly) butylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5
A polyol component such as pentanediol, cyclohexane-1,4-dimethanol, bisphenol A polyethoxydiol, hydrogenated bisphenol A, trimethylolpropane and maleic acid, succinic acid, fumaric acid, adipic acid, phthalic acid, isophthalic acid, Hexahydrophthalic acid,
Polymethacrylic acid such as tetrahydrophthalic acid, dimer acid, sebacic acid, azelaic acid, 5-sodium sulfoisophthalic acid and the like, and a (meth) acrylate of polyester polyol which is a reaction product thereof; Examples thereof include polyfunctional polyester (meth) acrylates such as (meth) acrylates of cyclic lactone-modified polyester polyols, which are reaction products of acids and their anhydrides with ε-caprolactone.

As a specific example of urethane (meth) acrylate, a reaction product of an organic isocyanate compound, a polyol compound and a hydroxyl group-containing (meth) acrylate compound can be mentioned as a typical example.

Specific examples of the organic polyisocyanate include P-phenylene diisocyanate, m-phenylene diisocyanate, P-xylene diisocyanate and m.
-Xylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,
Aromatic diisocyanates such as 4'-diphenylmethane diisocyanate and naphthalene diisocyanate; isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate,
4,4'-dicyclohexylmethane diisocyanate,
Aliphatic or alicyclic diisocyanates such as hydrogenated xylene diisocyanate, norbornene diisocyanate, and lysine diisocyanate; one or more burettes of isocyanate monomers, or polyisocyanates such as isocyanates obtained by trimerizing the above diisocyanate compound; and the like. To be

Specific examples of the polyol compound include the above-mentioned polyol component, polyester polyol, cyclic lactone-modified polyester polyol and the like.

Specific examples of the hydroxyl group-containing (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate and cyclohexanedimethanol mono (meth). Acrylate, 4
-Hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxy-
3-phenoxypropyl (meth) acrylate etc. can be mentioned.

Specific examples of the epoxy (meth) acrylate include a product obtained by reacting an epoxy resin containing a bifunctional or higher epoxy group with (meth) acrylic acid.

Specific examples of the epoxy resin include bisphenol A diglycidyl ether and hydrogenated bisphenol A.
Diglycidyl ether, bisphenol hexafluoroacetone diglycidyl ether, tetrabromobisphenol A diglycidyl ether, 1,3-bis [1-
(2,3-epoxypropoxy) -1-trifluoromethyl-2,2,2-trifluoroethyl] benzene,
1,4-bis [1- (2,3-epoxypropoxy)-
1-trifluoromethyl-2,2,2-trifluoroethyl] benzene, 4,4'-bis (2,3-epoxypropoxy) octafluorobiphenyl, spiroglycol diglycidyl ether, polyethylene glycol diglycidyl ether, phenol Typical examples are novolac type epoxy resins, but the present invention is not limited thereto.

As specific examples of maleimide compounds, any compound containing a maleimide group can be used.
Examples thereof include a 1 to 3 functional maleimide compound described in JP-A-58-40374 and a maleimide group-containing urethane oligomer described in JP-A-3-12414.

Further, as typical examples, N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-allylmaleimide, Nn-butylmaleimide, N-2. -Methyl-propylmaleimide, N-cyclohexylmaleimide, N-2-ethylhexylmaleimide, N- (2-
Dimethylaminoethyl) maleimide, N- (1-methoxymethylpropyl) maleimide, N, N'-1,6-hexane bismaleimide, bis (3-N-maleimidopropyl) polytetramethylene glycol, bis (2-N-
Maleimidopropyl) polypropylene glycol, bis (2-N-maleimidoethyl) polyethylene glycol, 1,2 (1,3 or 1,4) -bis (N-maleimidomethyl) cyclohexane,

[0025]

[Chemical 3]

[0026]

[Chemical 4]

[0027]

[Chemical 5]

And maleimide compounds in which hydrogen atoms bonded to unsaturated carbon atoms in maleimide groups of these maleimide compounds are substituted with chlorine atom, bromine atom, methyl group, ethyl group, methoxy group and the like. (In Chemical formula 4, a, b, and c each independently represent a number of 0 to 3, and a + b + c represents a number of 1 to 5).

Specific examples of vinyl ether compounds include hydroxymethyl vinyl ether, chloromethyl vinyl ether, hydroxyethyl vinyl ether, 1,
4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, 4-hydroxybutyl vinyl ether, trimethylolpropane trivinyl ether, cyclohexanedimethanol mono- or divinyl ether, cyclohexane mono- or divinyl ether, triethylene glycol divinyl ether polytetramethylene Examples thereof include glycol divinyl ether, polyurethane polyvinyl ether, polyester polyvinyl ether and the like.

Specific examples of N-vinyl compounds include N
-Vinylpyrrolidone, N-vinylcaprolactam, N-
Examples thereof include vinylformamide and N-vinylacetamide.

Preferred examples of the ethylenically unsaturated group-containing compound (B) other than the component (A) include acrylate monomers, acrylate oligomers and maleimide compounds.

In the present invention, a photopolymerization initiator (C) is used as an optional component. Specific examples of the photopolymerization initiator (C) include 2,2-diethoxyacetophenone, 2,2-diethoxy-2-phenylacetophenone, benzophenone and 1- (4-isopropylphenyl) -2-hydroxy-2-methyl. Propan-1-one, 2-hydroxy-
2-methyl-1-phenylpropan-1-one, benzoin ethyl ether, benzoin isobutyl ether,
Examples thereof include benzoin isopropyl ether, 1-hydroxycyclohexyl phenyl ketone, methylbenzisoformate, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

In the resin composition for an optical waveguide of the present invention, the ratio of the components (A) to (C) to be used is (A) component 1
The component (B) is preferably 10 to 500 parts by weight, particularly preferably 20 to 200 parts by weight, based on 00 parts by weight, and the total amount of the components (A) + (B) is 100 parts by weight.
The component (C) is preferably 0 to 10 parts by weight, particularly preferably 0.05 to 6 parts by weight.

In the present invention, if necessary, a silane coupling agent, a titanium coupling agent, a flexibility imparting agent, a characteristic modifier and the like can be added. The properties of the resin composition can be modified by adding these materials alone or in combination to the main component.

For example, the silane coupling agent added to enhance the adhesiveness of the resin composition of the present invention is γ-
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ
-Aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane,
N-β- (aminoethyl) -β- (aminoethyl) -γ
-Aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-β- (N-vinyl Benzylaminoethyl) -γ-amonopropyltrimethoxysilane hydrochloride group, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, γ-
Anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, methyltrichlorosilane, vinyltriethoxy Silane, γ-methacryloxypropyltris (2-methoxyethoxy) silane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like.

The resin composition of the present invention can be obtained by mixing and dissolving the components (A) to (C) and optionally the above-mentioned coupling agent and the like, and filtering in a clean room.

As a method of producing an optical waveguide in the present invention, the clad is slightly different when an ordinary polymer resin is used and when an ultraviolet curable resin similar to the core material is used.
As an example,

(1) A resin having a refractive index smaller than that of the core to be the lower clad is applied to an arbitrary substrate. After coating, the solvent is removed by heating and drying. When an ultraviolet curable resin is used here, it suffices that the resin is applied and then cured by ultraviolet rays. By using these cured resins, the step of removing the solvent can be omitted. (2) The resin of the present invention, which serves as a core, was applied thereon, and then was irradiated with ultraviolet rays through a negative mask having a waveguide pattern to be cured. After that, when this sample was developed with an organic solvent, only the light irradiation part was cured according to the mask pattern, and a waveguide pattern could be produced. (3) After that, a polymer resin for clad or an ultraviolet curable resin is applied on this, and the solvent is removed or the resin is cured by ultraviolet rays. Here, it is desirable that the lower clad and the clad on the side surface of the core and the upper clad to be finally formed have the same refractive index, and the same material is more preferable. Furthermore, when an ultraviolet curable resin is used for the clad, the uppermost surface can be flattened. In this case, in the case where a multi-layered optical wiring becomes possible and the multi-layering is performed, the above (2) and (3) may be repeated.

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. (Synthesis Example of Urethane Methacrylate Compound (A)) Synthesis Example 1 Bis (4-hydroxyethylthiophenyl) sulfide 338.2 g, tetrahydrofuran (THF) 500 m
Added liters. Then, it is heated to dissolve, 0.26 g of dibutyltin dilaurate and 0.26 g of P-methoxyphenol are charged at 50 ° C., 310 g of 2-isocyanate-ethyl methacrylate is added dropwise at 50 to 60 ° C. with stirring for about 1 hour, and then about Continue the reaction for 2 hours,
After confirming that no isocyanate-group remained, the reaction was terminated, and THF was distilled off with an evaporator.
By drying under reduced pressure (5 mmHg) for about 3 hours at 0 ° C., a liquid pale yellow substance was obtained. Refractive index of product (20
C., 589 nm) was 1.60, and the components of the following structural formula were the main components.

[0040]

[Chemical 6]

Example 1 Product obtained in Synthesis Example 1 (reaction product of a compound of the general formula (1) where R ₁ = H and R _{2 to} R ₅ = H and 2-isocyanate-ethyl methacrylate) 57 ．
1 g, phenoxyethyl acrylate 42.9 g and 1
-A resin composition (a) prepared from 3 g of hydroxycyclohexyl phenyl ketone (photopolymerization initiator) was prepared.
The refractive index of the resin composition (a) after curing has a wavelength of 589.
It was 1.590 in nm.

Next, on a silicon substrate, 14.3 g of the product obtained in Synthesis Example 1, phenoxyethyl acrylate 85.
The resin composition (b) prepared from 7 g and / or 3 g of hydroxycyclohexyl phenyl ketone (photopolymerization initiator) was applied by spin coating, and the entire surface was irradiated with ultraviolet rays to form a lower clad layer having a thickness of 10 μm.

Next, on the lower clad layer,
The resin composition (a) was applied by spin coating to a thickness of 5 μm. The refractive index of the lower clad layer after curing was 1.560 at a wavelength of 589 nm.

Next, ultraviolet rays were irradiated through a negative mask having a waveguide pattern, and then this sample was developed with γ-butyrolactone to prepare a waveguide pattern. Then, on this waveguide pattern and the lower clad layer,
The above resin composition (b) was applied to a thickness of 15 μm and irradiated with ultraviolet rays to be cured to prepare an optical waveguide. By this operation, the lower clad layer and the upper clad layer made of the cured product of the resin composition (b) having a refractive index of 1.560 after curing, and the resin composition (a) having a refractive index of 1.590 after curing.
A multi-mode channel waveguide having a core made of the cured product was prepared.

The obtained optical waveguide was cut into a length of 5 cm, and the optical waveguide loss was examined by using a He-Ne laser beam having a wavelength of 633 nm, and it was 0.35 dB / cm.

[0046]

As described above, according to the present invention, since the core material which does not use the solvent is used, the problem caused by the solvent is solved and the waveguide forming process is simplified. Further, since the flattening is easy, it is possible to realize an optical waveguide capable of multilayer optical wiring.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H047 PA15 PA28 QA05 TA05 TA41                 4J027 AA02 AG04 AG09 AG26 AG33                       BA07 BA09 BA10 BA13 BA19                       BA20 BA21 BA23 BA24 CA29                       CA31 CB10 CC05 CD03                 4J100 AE10Q AL04Q AL05Q AL08Q                       AL10Q AL65P AL65Q AL82Q                       AM43Q AQ08Q BA03Q BA04Q                       BA08Q BA34P BA40Q BA51P                       BB01P BB03P BB03Q BC08Q                       BC43P BC43Q BC53Q BC58Q

Claims (4)

[Claims] 1. A compound (a) represented by the general formula (1): (In the formula (1), R ₁ is a hydrogen atom or CH ₃ , R ₂ , R ₃ , R
₄ , R ₅ are the same or different and each represents a hydrogen atom, a halogen atom,
Or an alkyl group having 1 to 6 carbon atoms) and a urethane methacrylate compound (A) which is a reaction product of 2-isocyanate-ethyl methacrylate (b) and an ethylenically unsaturated group-containing compound (B) other than the component (A). A resin composition comprising: 2. The resin composition according to claim 1, which contains a photopolymerization initiator (C). 3. The resin composition according to claim 1, which is a resin composition for an optical waveguide. 4. A cured product of the resin composition according to claim 1.