KR20070018891A - Photocurable resin composition for forming optical waveguide, photocurable dry film for forming optical waveguide, and optical waveguide - Google Patents

Abstract

The photocurable resin composition and the photocurable dry film which are very useful for optical waveguide formation are provided.

The photocurable resin composition for optical waveguide formation containing the carboxyl group-containing unsaturated resin (A) obtained by making carboxyl group-containing resin (a) and an epoxy-group-containing unsaturated compound (b) react, and a solvent (B); And it provides the photocurable dry film for optical waveguide formation formed with the said resin composition.

Optical waveguide, photocurable resin composition, carboxyl group-containing resin, dry film

Description

PHOTOCURABLE RESIN COMPOSITION FOR FORMING OPTICAL WAVEGUIDE, PHOTOCURABLE DRY FILM FOR FORMING OPTICAL WAVEGUIDE, AND OPTICAL WAVEGUIDE}

The present invention relates to a photocurable resin composition for forming an optical waveguide, a photocurable dry film for forming an optical waveguide, and an optical waveguide.

Background Art In recent years, optical waveguides have been attracting attention as optical transmission media capable of responding to demands for increasing the capacity and speed of information processing in optical communication systems, computers, and the like.

Quartz waveguides (Quartz waveguides) are typical of such optical waveguides, but there are problems such as requiring a special manufacturing apparatus and a long manufacturing time.

In place of such a quartz waveguide, an organic polymer optical waveguide without the above problem has been developed.

Japanese Laid-Open Patent Publication No. 2003-149475 discloses an optical waveguide-forming resin composition containing an ethylenically unsaturated group-containing carboxylic acid resin, a diluent and a photopolymerization initiator having at least one ethylenically unsaturated group and at least one carboxyl group in a molecule. Doing.

However, this composition has a problem that the process for producing the ethylenically unsaturated group-containing carboxylic acid resin is complicated. That is, in manufacture of this resin, after reacting the epoxy resin which has at least 2 epoxy group in a molecule | numerator, (meth) acrylic acid, and the compound which has one carboxylic acid and two hydroxyl groups in a molecule | numerator as needed, a polybasic acid anhydride is further reacted. This requires a complicated process. Moreover, introduction of an unsaturated group and a carboxyl group in obtained resin may be inadequate.

Moreover, the said resin composition for optical waveguide formation has a fault that it is inferior to the processability, mechanical property, etc. of the coating film formed. Therefore, this composition is difficult to use with a dry film.

[Problem to Solve Invention]

An object of the present invention is to provide a photocurable resin composition and a photocurable dry film which can form a coating film excellent in workability, mechanical properties and the like, which are very useful for forming an optical waveguide, and an optical waveguide obtained therefrom.

[Means for solving the invention]

This invention provides the photocurable resin composition for optical waveguide formation, the photocurable dry film for optical waveguide formation, and an optical waveguide as shown below.

1. Photocurable resin composition for optical waveguide formation containing carboxyl group-containing unsaturated resin (A) obtained by making carboxyl group-containing resin (a) and epoxy group containing unsaturated compound (b) react, and solvent (B).

2. The photocurable resin composition for optical waveguide formation of the said Claim 1 which contains an optical radical polymerization initiator further.

3. The photocurable dry film for optical waveguide formation formed with the photocurable resin composition for optical waveguide formation of the said Claim 1.

4. An optical waveguide composed of a lower cladding layer (I), a core portion (II) and an upper cladding layer (III), wherein at least one of these components is formed from the photocurable resin composition for forming an optical waveguide according to item 1 above. Optical waveguide.

5. An optical waveguide composed of a lower cladding layer (I), a core portion (II) and an upper cladding layer (III), wherein at least one of these components is formed of a photocurable dry film for forming an optical waveguide according to item 3 above. Optical waveguide.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The photocurable resin composition for optical waveguide formation of this invention contains the carboxyl group-containing unsaturated resin (A) obtained by making carboxyl group-containing resin (a) react with an epoxy-group-containing unsaturated compound (b), and a solvent (B).

Carboxyl group  Containing resin (a)

The carboxyl group-containing resin (a) is a resin having an average of two or more, preferably three or more, carboxyl groups in one molecule. If the number of carboxyl groups is less than two in one molecule, the amount of carboxyl groups consumed in the reaction with the epoxy group-containing unsaturated compound (b) and remaining in the resin is reduced. Therefore, when light is irradiated to the photocurable resin composition, the solubility difference by the alkali developing solution of a light irradiation part and a non-irradiation part becomes small, and the boundary of a light irradiation part and a non-irradiation part becomes unclear, and a sharp core part There is a fear that it cannot be formed.

Moreover, it is preferable that it is 1000-100000, and, as for the number average molecular weight of carboxyl group-containing resin (a), it is more preferable that it is 2000-80000. When a number average molecular weight is less than 1000, there exists a possibility that the workability and the windability of the dry film formed of a photocurable resin composition may be inferior. Moreover, when light is irradiated to the photocurable resin composition, since the solubility difference by the alkali developing solution of a light irradiation part and a non-irradiation part becomes small, the boundary of a light irradiation part and a non-irradiation part will not become clear, and a sharp core part There is a possibility that it cannot be formed.

As carboxyl group-containing resin (a), if it is resin containing a carboxyl group, well-known resin can be used without a restriction | limiting in particular. For example, an acrylic resin (including vinyl resin), a carboxyl group-containing fluorine resin, a polyester resin, a silicone resin, an alkyd resin, a modified resin composed of two or more thereof, or a mixture of two or more thereof can be used. Among these, acrylic resin and carboxyl group-containing fluororesin are especially preferable.

Acrylic resin

As acrylic resin, (alpha), ß-ethylenic unsaturated acid, such as acrylic acid and methacrylic acid, is made into an essential monomer component, and this, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (Meth) acrylic acid esters such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, styrene, (meth) acrylonitrile, (meth) acrylamide and the like One copolymerized with at least one unsaturated monomer may be used.

Carboxyl group  Containing fluorine resin

Examples of the carboxyl group-containing fluororesin include α, ß-ethylenically unsaturated acids such as acrylic acid, methacrylic acid, maleic anhydride, maleic acid and itaconic acid as essential monomer components, and a perfluoroalkyl group or a perfluoroalkenyl group. Monomers having one end and an ethylenic double bond at the other end (preferably perfluorobutylethyl methacrylate, perfluorooctylethyl methacrylate, perfluoroisononylethyl methacrylate, perfluorodecylethyl Methacrylate) and those copolymerized with the above unsaturated monomers as necessary.

Fluoroolefins such as vinyl fluoride, vinylidene fluoride, ethylene trifluoride chloride and ethylene tetrafluoride; Hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxypentyl vinyl ether, ethylene glycol monoallyl ether, di Hydroxyl-containing radically polymerizable unsaturated monomers such as hydroxyallyl ether such as ethylene glycol monoallyl ether and triethylene glycol monoallyl ether; And α-olefins such as ethylene, propylene, isobutylene, butylene-1 and the like, if necessary; Vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; Vinyl acetate, vinyl lactate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl pivalate, vinyl caprylate fatty acid vinyl esters such as vinyl caprylate; A hydroxyl group-containing fluorine resin is prepared by copolymerizing other radically polymerizable unsaturated monomers such as fatty acid isopropenyl esters such as isopropenyl acetate and isopropenyl acetate, and then a polybasic acid anhydride (e.g., It is also possible to use an carboxyl group introduced by reacting itaconic anhydride, succinic anhydride and the like with addition).

Epoxy group-containing unsaturated compound (b)

An epoxy group containing unsaturated compound (b) has an average of 1 or more epoxy groups and an average of 1 unsaturated group in 1 molecule. For example, glycidyl (meth) acrylate, allyl glycidyl ether, vinylcyclohexene monooxide, 3, 4- epoxycyclohexylmethyl (meth) acrylate, etc. are mentioned.

In addition, epoxy resins such as bisphenol epichlorohydrin type epoxy resins, novolac epoxy resins, alicyclic polyepoxides, and (co) polymers of the above-mentioned epoxy group-containing unsaturated compounds are used, It is also possible to use those obtained by reacting α, ß-ethylenically unsaturated acids.

Carboxyl group  Containing unsaturated resin (A)

The carboxyl group-containing unsaturated resin (A) used in the present invention is a mixture of the carboxyl group-containing resin (a) and the epoxy group-containing unsaturated resin (b) in the presence of a catalyst such as tetraethylammonium bromide, for example, 80 It can manufacture easily by making it react at ~ 120 degreeC for 1 to 5 hours.

The photocurable resin composition for optical waveguide formation of this invention contains a carboxyl group-containing unsaturated resin (A), and is a composition which the unsaturated group in the said resin superposes | polymerizes, bridge | crosslinks, and hardens | cures by light irradiation. As light to irradiate, active energy rays, such as an electron beam, an ultraviolet-ray, a visible ray, can be used, for example. In addition, when irradiating an ultraviolet-ray or visible ray and crosslinking, an optical radical polymerization initiator and a photosensitizer (photosensitizing dye) can be mix | blended as needed.

A photo radical polymerization initiator can use a well-known thing. For example, aromatic carbonyl compounds, such as benzophenone, benzoin methyl ether, benzoin isopropyl ether, benzyl xanthone, thioxanthone, and anthraquinone; Acetophenone, propiophenone, a-hydroxyisobutylphenone, α, α'-dichloro-4-phenoxyacetophenone, 1-hydroxy-1-cyclohexylacetophenone, diacetylacetophenone, acetophenone, etc. Acetophenone compounds; Benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylhydroperoxide, di-t-butyldiperoxyisophthalate, 3,3 ', 4,4'-tetra (t-butylper Organic peroxides such as oxycarbonyl) benzophenone; Diphenylhalonium salts such as diphenyliodonium bromide and diphenyliodonium chloride; Organic halides such as carbon tetrabromide, chloroform and iodine form; Heterocyclic and polycyclic compounds such as 3-phenyl-5-isoxazoline, 2,4,6-tris (trichloromethyl) -1,3,5-triazine benzanthrone compound; 2,2'-azo (2,4-dimethylvaleronitrile), 2,2-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'- Azo compounds such as azobis (2-methylbutyronitrile); Iron-allen complex (see European Patent No. 152377); Titanocene compounds (see Japanese Patent Laid-Open No. 63-221110); Bisimidazole-based compounds; N-aryl glycidyl compounds; Acridine-based compounds; Combinations of aromatic ketones and aromatic amines; Peroxy ketal (refer Unexamined-Japanese-Patent No. 6-321895) etc. are mentioned.

Among the radical photopolymerization initiators, di-t-butyldiperoxyisophthalate, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, iron-ene complex and titanocene compound are crosslinked. Since the activity is high with respect to polymerization, it is preferable.

In addition, a commercial item can be used as an optical radical polymerization initiator. As a commercial item, for example, "Irgacure 651" (made by Chiba specialty chemicals company, a brand name, acetophenone type radical photopolymerization initiator), "Irgacure 184" (made by Chiba specialty chemicals company, a brand name, acetophenone type light) Radical polymerization initiator), "Irgacure 1850" (made by Chiba specialty chemicals company, brand names, acetophenone type radical photopolymerization initiator), "Irgacure 907" (made by Chiba specialty chemicals company, brand name, aminoalkyl phenone type optical radicals) Polymerization initiator), "Irgacure 369 (made by Chivas specialty chemicals company, brand names, aminoalkyl phenone type radical photopolymerization initiator)," Lucirine TPO "(product made from BASF Corporation, brand name, 2,4,6-trimethylbenzoyldiphenylforce) Pin oxide), "Kayacure DETXS" (made by Nihon Kayaku Co., Ltd., brand name), "CGI-784" (made by Chiba Specialty Chemicals Corporation, brand name, titanium complex compound), etc. are mentioned.

The said radical photopolymerization initiator can be used individually by 1 type or in combination of 2 or more types.

It is preferable that the compounding ratio at the time of mix | blending an optical radical polymerization initiator with the photocurable resin composition of this invention is about 0.5-10 weight part with respect to 100 weight part of carboxyl group-containing unsaturated resins (A).

As a photosensitizer, for example, thioxanthene type, xanthene type, ketone type, thiopyrylium salt type, bisstyryl type, merocyanine ), 3-substituted coumarin series, 3,4-substituted coumarin series, cyanine series, acridine series, thiazine series, phenothiazine series, anthracene series, coronene series, benzanthracene series, perylene series, merocyanine series, ke And pigments such as tokumarin, fumarin, and borate. These pigments can be used individually by 1 type or in combination of 2 or more types. Examples of the borate-based light-sensitizing dyes include those described in JP-A-5-241338, JP-A-7-5685, and JP-A-7-225474. have.

The curing agent, such as polyepoxide which bridge | crosslinks the carboxyl group of a carboxyl group-containing unsaturated resin (A), can be mix | blended with the photocurable resin composition for optical waveguide formation of this invention as needed.

As said polyepoxide, Bisphenol-type epoxy resin obtained by reaction of a bisphenol compound and haloepoxides, such as epichlorohydrin or ß-methyl epichlorohydrin; Halogenated bisphenol type epoxy resins; Phosphorus modified bisphenol-type epoxy resin which made the phosphorus compound chemically react; Alicyclic epoxy resins obtained by hydrogenation of bisphenol type epoxy resins; Novolak-type epoxy resins obtained by reacting a phenol novolak resin and a cresol novolak resin with a haloepoxide; Glycidyl ester epoxy resins obtained by reacting polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; Glycidyl amine type epoxy resins obtained by reacting polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; Linear aliphatic epoxy resins and alicyclic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; And biphenyl-type epoxy resins obtained by reacting biphenols with epichlorohydrin.

It is preferable to mix | blend a bisphenol-type epoxy resin, a novolak-type epoxy resin, etc. with a large heat resistance improvement effect required for an optical waveguide among the said polyepoxide.

In the case of forming the lower cladding layer of the optical waveguide with the photocurable resin composition for optical waveguide formation of the present invention, the curing agent is further cured, for example, by curing the lower cladding layer, and then further heating the carboxyl group-containing unsaturated resin (A). By reaction of the derived carboxyl group and the curing agent, a harder lower cladding layer can be formed. In the same manner as in the case of forming the core portion or the upper cladding layer, the core portion or the upper cladding layer is photocured and further heated to react the carboxyl group derived from the carboxyl group-containing unsaturated resin (A) with the curing agent. A harder core portion or upper cladding layer can be formed.

In addition, in these layer formation, you may harden | cure by heating every time each layer is formed, or after forming two layers or three layers, you may heat and harden two or three layers simultaneously.

The range of the epoxy group of 0.1-1.5 mol is preferable with respect to 1 mol of carboxyl groups, and, as for the mixture ratio of hardening agents, such as polyepoxide, the range of 0.5-1.1 mol is more preferable.

By mix | blending so that a carboxyl group may not remain in each layer after heat-hardening (especially in an upper cladding layer), performance, such as water resistance, heat resistance, and moisture resistance of an optical waveguide, will improve.

In the photocurable resin composition for optical waveguide formation of this invention, unsaturated compounds other than what was mentioned above, adhesion promoter, hydroquinone, 2, 6- di-t- butyl- p-cresol, N, N- diphenyl as needed Polymerization inhibitors such as -p-phenylenediamine, organic resin fine particles such as saturated resins, unsaturated resins, and unsaturated polymers (including unsaturated groups), various pigments such as colored pigments and extender pigments, and metal oxides such as cobalt oxide. , Plasticizers such as dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, polyethylene glycol, polypropylene glycol, anticissing agents, fluidity regulators, and the like.

Examples of the unsaturated compound include compounds having preferably 1 to 4 radically polymerizable unsaturated groups, and monomers, dimers, and trimers which bring about insolubilization of portions exposed to light by addition polymerization when exposed to light. Sieves and other oligomers. As an unsaturated compound, other than monomers, such as said (meth) acrylic acid ester and styrene, For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Poly (4-16) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethylene glycol diitaco more than tetra Nate, ethylene glycol dimaleate, hydroquinone di (meth) acrylate, resorcinol di (meth) acrylate, pyrogallol (meth) acrylate, oligourethane acrylate, oligoepoxy acrylate, di The polyfunctional unsaturated compound which has two or more unsaturated groups, such as vinylbenzene, is mentioned. The said unsaturated compound can be used individually by 1 type or in combination of 2 or more types.

It is preferable that it is 200 weight part or less with respect to 100 weight part of said carboxyl group-containing unsaturated resins (A), and, as for the usage-amount of these unsaturated compounds, it is more preferable that it is 3-100 weight part.

The said saturated resin can be used in order to suppress solubility of the film of a photocurable resin composition. For example, it can be used in order to suppress solubility to the alkali developer etc. of a composition film. As this saturated resin, a polyester resin, an alkyd resin, (meth) acrylic resin, a vinyl resin, an epoxy resin, a phenol resin, a natural resin, a synthetic rubber, a silicone resin, a fluororesin, a polyurethane resin etc. are mentioned, for example. have. These resin can be used individually by 1 type or in combination of 2 or more types.

As said unsaturated resin, it is preferable to contain an average of about 1-10 unsaturated groups in 1 molecule in said saturated resin, and it is more preferable to contain an average of about 1-4 unsaturated groups in 1 molecule.

It is preferable that it is 200 weight part or less per 100 weight part of said carboxyl group-containing unsaturated resins (A), and, as for the usage-amount of these saturated resin and / or unsaturated resin, it is more preferable that it is 3-100 weight part.

In the photocurable resin composition of the present invention, if necessary, for example, fillers, colorants, leveling agents, heat stabilizers, discoloration inhibitors, antioxidants, mold release agents, surface treatment agents, flame retardants, viscosity modifiers, plasticizers, antibacterial agents, mold inhibitors ( mildew-proofing agents), antifoaming agents, coupling agents and the like may be added.

The photocurable resin composition for optical waveguide formation of this invention is prepared by melt | dissolving or disperse | distributing the said carboxyl group-containing unsaturated resin (A) and optical radical polymerization initiator etc. in the solvent (B), such as an organic solvent and water, as needed.

It is preferable that the usage-amount of a solvent (B) is about 30-2000 weight part per 100 weight part of carboxyl group-containing unsaturated resin (A).

The organic solvent-based liquid resin composition dissolves the carboxyl group-containing unsaturated resin (A) and optional components in organic solvents such as ketones, esters, ethers, cellosolves, aromatic hydrocarbons, alcohols, and halogenated hydrocarbons. Or by dispersing. The composition is applied onto the substrate forming the optical waveguide by means of a roller, a roll coater, a spin coater, a curtain roll coater, a spray, an electrostatic coating, an immersion coating, a silk printing, and the like, and set as necessary. After drying, an optical waveguide film can be obtained.

An aqueous liquid resin composition can be obtained by melt | dissolving or disperse | distributing the said carboxyl group-containing unsaturated resin (A) and arbitrary components in water or water and an organic solvent mixture. The solubilization or water dispersion of the carboxyl group-containing unsaturated resin (A) is performed by neutralizing the carboxyl group in the resin (A) with a neutralizing agent (alkali).

As the neutralizer, for example, monoethanolamine, diethanolamine, triethylamine, diethylamine, dimethylaminoethanol, cyclohexylamine, ammonia and the like can be used. It is preferable that it is 0.2-1.0 equivalent per carboxyl group, and, as for the usage-amount of a neutralizing agent, it is more preferable that it is 0.3-0.8 equivalent.

The photocurable dry film for forming the optical waveguide of the present invention may be formed by, for example, a roll coater, a blade coater, a curtain flow coater, or the like using the organic solvent-based liquid resin composition or the aqueous liquid resin composition on a base film. coater) and the like can be applied and dried. 1 micrometer-about 2 mm are preferable, and, as for the dry film thickness of a dry film, 1 micrometer-about 1 mm are more preferable.

As the base film, for example, a film such as polyethylene terephthalate, aramid, Kapton, polymethylpentene, polyethylene, polypropylene, etc. can be used, but it is preferable to use a polyethylene terephthalate film in terms of cost and dry film. It is preferable at the point which acquires a characteristic. It is preferable that it is 1 micrometer-10 mm, and, as for the film thickness of a base film, it is more preferable that it is 10 micrometers-1 mm.

The obtained dry film is exposed or cured, for example, in visible light so as to form an optical waveguide, without peeling or peeling off the base film, and if there is a base film, peeling it off, and if not, itself Can be used for optical waveguide formation. In order to form a core part from this dry film, this dry film may be developed. In a dry film, a cover coat layer can be provided as needed. The cover coat layer may be formed by coating on a dry film or may be pasted on a dry film.

It is preferable that it is 0-200 degreeC, and, as for the softening temperature of the photocurable dry film for optical waveguide formation of this invention, it is more preferable that it is 10-150 degreeC. If the softening temperature of the dry film is less than 0 ° C., the dry film softens and becomes sticky by heating when the dry film is adhered to the substrate, so that the sticking operation may be remarkably difficult, or bubbles may occur after the sticking. There is. When the softening temperature of a dry film exceeds 200 degreeC, there exists a possibility that sticking may become difficult.

In the present specification, the softening temperature is a value measured by the heat deformation behavior of a 1 mm thick sheet using a thermomechanical analyzer. That is, a needle made of quartz was placed on the sheet, and the temperature of the needle penetrated by 0.635 mm was set as the softening temperature while increasing the temperature at 5 ° C / min under a load of 49 g. As a thermomechanical analyzer, the apparatus marketed by Dupont Corporation can be used, for example.

As a light source used for photocuring, ultrahigh pressure, high pressure, medium pressure, low pressure mercury lamp, chemical lamp, carbon arc, etc., xenon, metal halides, tungsten, etc. are mentioned, for example. In addition, various lasers having oscillation lines in the ultraviolet region or the visible region can also be used. As a laser, an argon laser (oscillation line 355 nm), a YAG-THG laser (oscillation line 355 nm), a semiconductor (InGaN) laser (oscillation line 405 nm), an argon laser (oscillation line 488 nm), YAG- SHG laser (oscillation line 532 nm) and the like are preferable.

The optical waveguide of the present invention is an optical waveguide composed of a lower cladding layer (I), a core portion (II) and an upper cladding layer (III), and at least one of these components is the photocurable resin composition for forming the optical waveguide described above. Or it is formed with the photocurable dry film for optical waveguide formation.

In the optical waveguide of the present invention, all of the lower cladding layer (I), the core portion (II), and the upper cladding layer (III) may be formed of the optical waveguide formation photocurable resin composition of the present invention, or all of them may be seen. It can also form with the photocurable dry film for optical waveguide formation of this invention. Moreover, you may form combining the photocurable resin composition for optical waveguide formation of this invention, and the photocurable dry film for optical waveguide formation. Moreover, you may form combining some well-known composition for optical waveguide formation and a dry film.

Hereinafter, the lower cladding layer (I), the core portion (II), and the upper cladding layer (III) will be described.

bottom Cladding layer (Ⅰ)

Lower cladding layer (I) is formed using curable resin composition or a dry film on the base material for optical waveguides, for example.

Examples of the substrate include silicon substrates, quartz substrates, polyimide substrates, PET substrates, liquid crystal polymer substrates, copper foils, copper clad laminates, circuit forming substrates, and the like.

The lower cladding layer (I) is made of, for example, a photocurable resin composition for forming an optical waveguide of the present invention, a photocurable dry film for forming an optical waveguide of the present invention, a thermosetting resin, or an active energy ray curable resin. It can be formed using the composition and the like.

As a thermosetting resin, For example, combination of the base resin which has a thermoreactive functional group, and the hardening | curing agent which has a functional group which reacts with the said functional group; Self-crosslinking types such as N-methylol group and N-alkoxymethylol group can be used.

As a combination of a thermally reactive functional group and the functional group which reacts with this, for example, a carboxyl group and an epoxy group (oxysilane group), a carboxylic anhydride and an epoxy group (oxysilane group), a carboxylic anhydride and an oxetane groups, an amino group and an epoxy group (Oxysilane group), a carboxyl group and a hydroxyl group, a carboxylic anhydride and a hydroxyl group, a blocked isocyanate group, a hydroxyl group, an isocyanate group, an amino group, etc. are mentioned.

As well-known active energy ray curable resin, it is a functional group containing compound which can carry out 2 or more ring-opening polymerization in a molecule | numerator as an essential component, using an active energy ray polymerization initiator together as needed; Using a polymerizable unsaturated compound, unsaturated resin, etc. together with an active energy ray polymerization initiator as needed can be used.

The lower cladding layer (I) can be formed by removing a solvent after coating and printing the said well-known resin composition or the resin composition of this invention on the base material for optical waveguides. Furthermore, after removing a solvent or removing a solvent, an active energy ray can be irradiated or heated as needed, and hardening and drying of a coating film can be carried out.

Moreover, a dry film layer can be formed on the surface of a base film by removing a solvent after coating and printing the said well-known resin composition or the resin composition of this invention on a base film. Subsequently, the base film may be peeled off, and the dry film may be affixed to the substrate for the optical waveguide by heating and / or compression to form the lower cladding layer (I). Further, the laminated film having the dry film layer formed on the surface of the base film is affixed to the substrate for an optical waveguide by heating and / or pressing, and then the base film is peeled off to form a lower cladding layer (I) on the surface of the substrate for the optical waveguide. It may be formed.

The lower cladding layer (I) may be cured or dried as necessary by active energy ray irradiation or heating.

As a method of forming the lower cladding layer (I), a method of forming using a dry film is particularly preferable in terms of environmental conservation, safety, workability and the like.

Further, as the lower cladding layer (I), it is preferable to cure the photocurable resin composition for forming the optical waveguide of the present invention or the photocurable dry film for forming the optical waveguide of the present invention in terms of durability, heat resistance, processability, and light transmission characteristics. Do.

Core part (Ⅱ)

The core portion II is formed on a part of the lower cladding layer I surface.

It is preferable to form core part (II) using the photocurable resin composition for optical waveguide formation of this invention, or the photocurable dry film for optical waveguide formation of this invention.

In forming the core part (II) using the photocurable resin composition for optical waveguide formation of this invention, the said resin composition is coated and printed on the lower cladding layer (I) surface, a solvent is removed, and a composition film is formed. . Subsequently, light is irradiated onto the film to form a core portion pattern. Subsequently, the core portion II can be formed by removing the non-irradiated portion by development.

In addition, by coating and printing the resin composition on the base film, and then removing the solvent, it is possible to form a dry film layer on the surface of the base film. Subsequently, the base film is peeled off, and the dry film can be affixed on the lower cladding layer (I) by heating and / or compression to form a composition film. Further, the laminated film having a dry film layer formed on the surface of the base film is affixed on the lower cladding layer (I) by heating and / or pressing, and then the base film is peeled off to form a composition film on the lower cladding layer (I). May be formed.

Subsequently, light irradiation is performed so that a core portion pattern is formed on the surface of the composition film. Subsequently, the core portion II can be formed by removing the non-irradiated portion by development.

Top Cladding layer (Ⅲ)

Upper cladding layer (III) is formed on the surface of lower cladding layer (I) and core part (II) using curable resin composition or a dry film.

The upper cladding layer (III) is, for example, a photocurable resin composition for forming an optical waveguide of the present invention, a photocurable dry film for forming an optical waveguide of the present invention, a thermosetting resin, or an active energy ray curable resin. It can be formed using the composition and the like.

The upper cladding layer (III) can be formed by the same method as the formation method of the lower cladding layer (I).

Specifically, the upper cladding layer (III) is formed by coating and printing the above-mentioned known resin composition or the resin composition of the present invention on the surfaces of the lower cladding layer (I) and the core portion (II), and then removing the solvent. can do. In addition, after removing a solvent or removing a solvent, an active energy ray can be irradiated or heated as needed, and a coating film can be hardened or dried.

Moreover, a dry film layer can be formed on the surface of a base film by coating and printing the said well-known resin composition or the resin composition of this invention on a base film, and then removing a solvent. Subsequently, the base film may be peeled off, and the dry film may be affixed to the surfaces of the lower cladding layer (I) and the core portion (II) by heating and / or pressing to form the upper cladding layer (III). Further, a laminated film having a dry film layer formed on the surface of the base film is affixed to the surfaces of the lower cladding layer (I) and the core portion (II) by heating and / or pressing, and then the base film is peeled off to form an upper cladding layer ( III) may be formed.

The upper cladding layer (III) may be further cured or dried by active energy ray irradiation, heating, or the like as necessary.

As a method of forming the upper cladding layer (III), a method of forming using a dry film is particularly preferable in terms of environmental conservation, safety, workability and the like.

In addition, as the upper cladding layer (III), curing the optical waveguide-forming photocurable resin composition of the present invention or the optical waveguide-forming photocurable dry film of the present invention is preferable in terms of durability, heat resistance, processability, and light transmission characteristics. .

Upper cladding layer (III) is a dry film before affixing on the surface of lower cladding layer (I) and core part (II), It is preferable that softening temperature is 0-300 degreeC, It is more preferable that it is 15-200 degreeC. Do. If the softening temperature of a dry film is lower than the said range, since a dry film softens and becomes sticky by the heating at the time of sticking a dry film, a sticking operation may become remarkably difficult or a bubble may arise after sticking. On the other hand, when it exceeds the said range, there exists a possibility that sticking may become difficult.

Moreover, it is preferable that the softening temperature of the dry film which forms upper cladding layer (III) is lower than the softening temperature of core part (II), and it is especially preferable that it is 10 degreeC or more low.

When forming the upper cladding layer (III), the surface of the core part (II) and the lower cladding layer (I) and the surface of the dry film on a base film are overlapped, and they are 10 degreeC or more higher than the softening temperature of the dry film. Appropriate heat and pressure can be obtained by compression methods such as atmospheric-pressure hot roll bonding, vacuum hot roll bonding, and vacuum hot press bonding at temperature. It is applied to the surface of the base film, and the base film is peeled from the dry film, and the dry film is transferred to the core portion (II) and the lower cladding layer (I), thereby to the surface of the core portion (II) and the lower cladding layer (I). The upper cladding layer can be formed.

The upper cladding layer (III) may be further cured or dried by active energy ray irradiation, heating, or the like as necessary.

In the optical waveguide of the present invention, it is preferable that, among the lower cladding layer (I) and the upper cladding layer (III), the difference in specific refractive index between the layer having a higher refractive index and the core portion (II) is 0.1% or more.

Here, the difference in specific refractive index in the present specification is defined by the following equation (1).

Specific refractive index difference (%) = [(n ₁ -n ₂ ) / n ₂ ] × 100

In the formula, n ₁ is the refractive index of the core portion (Ⅱ), n ₂ is the refractive index of the high refractive index layer than in the lower cladding layer (Ⅰ) and an upper cladding layer (Ⅲ). These refractive indices are measured with light having a wavelength of 850 nm using an Abbe refractometer.

In order to say the said difference in specific refractive index, it is required that the refractive index of the core part II is larger than the refractive index of either the lower cladding layer I and the upper cladding layer III.

In the optical waveguide of the present invention, for the light having a wavelength of 400 to 1,700 nm, the refractive index of the core portion (II) is usually within the range of 1.420 to 1.650, and the lower cladding layer (I) and the upper cladding layer ( It is preferable to make refractive index of III) into the value within the range of 1.400-1.648, respectively. Adjustment of refractive index can be adjusted by selecting suitably resin, an additive, these compounding quantities, etc. to be used.

In the optical waveguide of the present invention, the thickness of the lower cladding layer (I), the upper cladding layer (III), and the core portion (II) is not particularly limited, respectively, but for example, the thickness of the lower cladding layer (I). It is preferable to make 1-200 micrometers, the thickness of core part (II) 1-200 micrometers, and the thickness of upper cladding layer (III) 1-200 micrometers. In addition, the width of the core portion (II) is not particularly limited, but is preferably 1 to 200 m.

In the present specification, as the active energy ray and the light ray, visible ray, ultraviolet ray, infrared ray, X ray, α ray, β ray, γ ray and the like can be used. As the irradiation apparatus, 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. The dose is not particularly limited. It is preferable to irradiate radiation of wavelength 200-440 nm and illumination intensity 1-500 mW / cm <^2> so that irradiation amount may be 10-5,000 mJ / cm <^2> , and to expose to light.

Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples.

Production Example 1 Preparation of Photocurable Resin Composition (1)

40 g of methyl methacrylate, 20 g of styrene, 20 g of butyl acrylate and 20 g of acrylic acid were subjected to radical reaction at 110 ° C to obtain an acrylic resin (resin acid value of 155 mgKOH / g). Then, 24 g of glycidyl methacrylate, 0.12 g of hydroquinone and 0.6 g of tetraethylammonium bromide were added to the resin, and the mixture was reacted at 110 ° C. for 5 hours while blowing air to obtain a photocurable resin. Next, 100 g of said photocurable resin (solid content), 3 g of aminoalkyl phenone type polymerization initiators (made by Chiba Specialty Chemicals, brand name "Irgacure 907"), and 400 g of ethyl acetate were mixed, and the photocurable resin composition (1 )

Production Example 2 Preparation of Photocurable Resin Composition (2)

In Preparation Example 1, photocurability was obtained in the same manner as in Preparation Example 1, except that 20 g of methyl methacrylate, 40 g of styrene, 20 g of butyl acrylate, and 20 g of acrylic acid were used as monomer components of the acrylic resin. The resin composition (2) was obtained.

Production Example 3 Preparation of Photocurable Resin Composition (3)

352 g of hydrogenated bisphenol A diglycidyl ether, 141.2 g of acrylic acid, 0.2 g of p-methoxy phenol, and 1.5 g of triphenylphosphine were reacted at 95 ° C. for about 32 hours, and the acid value of the reaction system was 0.5 mgKOH / g or less. At that point, the reaction was terminated. Subsequently, 70 g of succinic anhydride was added and reacted at 90 ° C. for about 10 hours to obtain an acid value of 70 mgKOH / g (photocurable resin). Subsequently, 60 g of the product, diacrylate of 5-ethyl-2- (2-hydroxy-1,1-dimethylethyl) -5- (hydroxymethyl) -1,3-dioxane (Nihon Chemical Co., Ltd.) ), Brand name "KATARAD R-604") and 3 g of 1-hydroxycyclohexylphenyl ketone were mixed, and the photocurable resin composition (3) was obtained.

Production Example 4 Production of Photocurable Dry Film (D-1)

The photocurable resin composition (1) was applied onto a polyethylene terephthalate film (film thickness of 25 μm) with a knife edge coater, and dried at 80 ° C. for 30 minutes to provide a photocurable dry film (D-1). Got it.

Production Example 5 Manufacture of Photocurable Dry Film (D-2)

The photocurable resin composition (2) was apply | coated on the polyethylene terephthalate film (film thickness of 25 micrometers) with the knife edge coater, and it dried at 80 degreeC for 30 minutes, and obtained the photocurable dry film (D-2).

Production Example 6 Manufacture of Photocurable Dry Film (D-3)

In Preparation Example 3, a photocurable resin composition was obtained in the same manner as in Preparation Example 3, except that bisphenol A diglycidyl ether was used instead of hydrogenated bisphenol A diglycidyl ether. The composition was applied onto a polyethylene terephthalate film (film thickness of 25 μm) with a knife edge coater, and then dried at 80 ° C. for 30 minutes to obtain a photocurable dry film (D-3).

Example 1 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable resin composition (1) was apply | coated by the spin coat method on the surface of a silicon substrate, the ultraviolet-ray of wavelength 365nm and illumination intensity 10mW / cm <^2> was irradiated for 100 second, and the lower cladding layer of thickness 40micrometer was formed.

(2) formation of the core portion

Then, the photocurable resin composition 2 was apply | coated by the spin coat method on the said lower cladding layer, and it dried at 80 degreeC for 30 minutes. Thereafter, ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² were irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm. Subsequently, the substrate having the resin composition layer irradiated with ultraviolet rays was immersed in a developer composed of an aqueous 1.8 wt% tetramethylammonium hydroxide solution to dissolve the unexposed portion of the resin composition layer and then dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed.

(3) formation of the upper cladding layer

The photocurable resin composition 1 was applied to the surface of the core portion and the lower cladding layer by spin coating, and the upper cladding layer having a thickness of 40 μm was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. Formed.

About the obtained optical waveguide, the transmission loss, core gap, precision of core shape, covering property, and workability of a core part were evaluated by the following method. As a result, the transmission loss was A, the interval between the core portions was A, the precision of the core portion shape was A, the coverability of the core portion was B, and the workability was B.

Transmission loss: The transmission loss per unit length was calculated | required by the cut-back method by injecting the light of wavelength 850 nm in one end into the optical waveguide, and measuring the light quantity emitted from the other end. A indicates that the transmission characteristics are good at a loss of 0.4 dB / cm or less, and B indicates that the transmission characteristics are deteriorated when the loss exceeds 0.4 dB / cm.

Interval of core part: A indicates that there is no gap between the convex part which is a core part, and upper cladding layer, B which made the gap, and boiled and bubbled when the organic solvent type composition was used.

Accuracy of core portion shape: A indicates that the core portion is not deformed by the upper cladding layer, and B indicates that the core portion is deformed by the upper cladding layer.

The coating property of the core part: A is that the upper cladding layer is coated with a sufficient film thickness of the convex part of the core part, B is that the film thickness of the upper cladding layer is coated with the convex part of the core part is slightly thin, and C is the upper cladding layer. The film thickness coated on the convex part of this core part is thin.

Workability: A is simple and easy to form the optical waveguide through the whole process, B is a little complicated to form the optical waveguide throughout the whole process, C is a complex and easy to form the optical waveguide throughout the whole process. Point out that you did not.

In addition, the refractive index of the film sample obtained from the resin composition which provided the cladding layer and the core part was measured at 23 degreeC with the interference filter of wavelength 850 nm with the multi-wavelength Abbe refractometer "DR-M4" by the Atago company. The specific refractive index difference (%) was computed by the said Formula (1) using this refractive index value. The difference in specific refractive index between the core portion and the cladding layer was 0.1% or more.

Example 2 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable dry film (D-1) is transferred onto the surface of the silicon substrate by an atmospheric pressure hot roll pressing method (temperature: 100 ° C), irradiated with ultraviolet light having a wavelength of 365 nm and an illumination intensity of 10 mW / cm ² for 100 seconds. After the formation, the polyethylene terephthalate film was peeled off to form a lower cladding layer having a thickness of 40 µm.

(2) formation of the core portion

Thereafter, the photocurable dry film (D-2) was transferred onto the lower cladding layer by an atmospheric pressure roll rolling method (temperature: 100 ° C). Thereafter, an ultraviolet ray having a wavelength of 365 nm and an illuminance of 10 mW / cm ² was irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm, and then the polyethylene terephthalate film was peeled off. Next, the board | substrate with the resin composition layer irradiated with ultraviolet-ray was immersed in the developing solution which consists of 1.8 weight% tetramethylammonium hydroxide aqueous solution, the unexposed part of the resin composition layer was melted, and dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed.

(3) formation of the upper cladding layer

The photocurable dry film (D-1) is transferred to the surface of the core part and the lower cladding layer by an atmospheric pressure hot roll pressing method (temperature: 100 ° C.), and ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. After irradiating and photocuring, the polyethylene terephthalate film was peeled off and the upper cladding layer of thickness 40micrometer was formed.

As a result of evaluating the obtained optical waveguide by the above method, the transmission loss was A, the spacing of the core portion was A, the accuracy of the core portion shape was A, the coverability of the core portion was A, and the workability was A.

In addition, the difference in specific refractive index between the core portion and the cladding layer was 0.1% or more.

Comparative Example 1 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable resin composition (3) was apply | coated on the surface of a silicon substrate by the spin coat method, the ultraviolet-ray of wavelength 365nm and illumination intensity 10mW / cm <^2> was irradiated for 100 second, and the lower cladding layer of thickness 40micrometer was formed.

(2) formation of the core portion

Thereafter, the photocurable dry film (D-3) was transferred onto the lower cladding layer by an atmospheric pressure roll press method (temperature: 100 ° C). Thereafter, an ultraviolet ray having a wavelength of 365 nm and an illuminance of 10 mW / cm ² was irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm, and then the polyethylene terephthalate film was peeled off. Next, the board | substrate with the resin composition layer irradiated with ultraviolet-ray was immersed in the developing solution which consists of 1.8 weight% tetramethylammonium hydroxide aqueous solution, the unexposed part of the resin composition layer was melted, and dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed.

(3) formation of the upper cladding layer

The photocurable resin composition 3 was applied to the surface of the core portion and the lower cladding layer by spin coating, and the upper cladding layer having a thickness of 40 μm was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. Formed.

As a result of evaluating the obtained optical waveguide by the said method, the transmission loss was A, the space | interval of a core part was B, the precision of the core part shape was B, the coating | cover property of the core part was C, and workability was B. FIG.

Production Example 7 Preparation of Photocurable Resin Composition (4)

40 g of methyl methacrylate, 20 g of styrene, 20 g of butyl acrylate and 20 g of acrylic acid were subjected to radical reaction at 110 ° C to obtain an acrylic resin (resin acid value of 155 mgKOH / g). Then, 24 g of glycidyl methacrylate, 0.12 g of hydroquinone and 0.6 g of tetraethylammonium bromide were added to the resin and reacted at 110 ° C. for 5 hours while blowing air to obtain a photocurable resin (the same as that obtained in Production Example 1). Same photocurable resin) was obtained. Next, 124 g of said photocurable resin (solid content), an aminoalkyl phenone type polymerization initiator (Ciba specialty Chemicals make, brand name "irgacure 907") 3 g, Epicoat EP-828EL (made by Japan Epoxy Resin Co., Ltd.) 20 g and 400 g of ethyl acetate were mixed to obtain a photocurable resin composition (4).

Production Example 8 Preparation of Photocurable Resin Composition (5)

124 g of photocurable resin (solid content) as obtained in the manufacture example 2, 3 g of aminoalkyl phenone type polymerization initiators (made by Chiba specialty chemicals company, brand name "irgacure 907"), Epicoat EP-828EL (Japan Epoxy Resin Co., Ltd.) 20g of brand names) and 400g of ethyl acetate were mixed, and the photocurable resin composition (5) was obtained.

Production Example 9 Preparation of Photocurable Resin Composition (6)

124 g of photocurable resin (solid content) as obtained in the manufacture example 3, 3 g of aminoalkyl phenone type polymerization initiators (made by Chiba specialty chemicals company, brand name "irgacure 907"), Epicoat EP-828EL (Japan Epoxy Resin Co., Ltd.) 20g of brand names) and 400g of ethyl acetate were mixed, and the photocurable resin composition (6) was obtained.

Production Example 10 Preparation of Photocurable Dry Film (D-4)

The photocurable resin composition (4) was apply | coated on the polyethylene terephthalate film (film thickness of 25 micrometers) with the knife edge coater, and it dried at 80 degreeC for 30 minutes, and obtained the photocurable dry film (D-4).

Production Example 11 Manufacture of Photocurable Dry Film (D-5)

The photocurable resin composition (5) was apply | coated on the polyethylene terephthalate film (film thickness of 25 micrometers) with the knife edge coater, and it dried at 80 degreeC for 30 minutes, and obtained the photocurable dry film (D-5).

Production Example 12 Preparation of Photocurable Dry Film (D-6)

A photocurable resin was obtained in the same manner as in Preparation Example 3, except that Bisphenol A diglycidyl ether was used instead of hydrogenated bisphenol A diglycidyl ether in Preparation Example 3. Then, 124 g of said photocurable resin (solid content), an aminoalkyl phenone type polymerization initiator (made by Chiba Specialty Chemicals, brand name "irgacure 907"), Epicoat EP-828EL (made by Japan Epoxy Resin Co., Ltd., brand name) ) 20 g and 400 g of ethyl acetate were mixed to obtain a photocurable resin composition. The composition was applied onto a polyethylene terephthalate film (film thickness of 25 μm) with a knife edge coater, and then dried at 80 ° C. for 30 minutes to obtain a photocurable dry film (D-6).

Example 3 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable resin composition 4 was apply | coated on the surface of a silicon substrate by the spin coat method, the ultraviolet-ray of wavelength 365nm and illumination intensity 10mW / cm <^2> was irradiated for 100 second, and the lower cladding layer of thickness 40micrometer was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(2) formation of the core portion

Then, the photocurable resin composition 5 was apply | coated by the spin coat method on the said lower cladding layer, and it dried at 80 degreeC for 30 minutes. Thereafter, ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² were irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm. Subsequently, the substrate having the resin composition layer irradiated with ultraviolet rays was immersed in a developer composed of an aqueous 1.8 wt% tetramethylammonium hydroxide solution to dissolve the unexposed portion of the resin composition layer and then dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(3) formation of the upper cladding layer

The photocurable resin composition 4 was applied to the surface of the core portion and the lower cladding layer by spin coating, and the upper cladding layer having a thickness of 40 μm was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. Formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

As a result of evaluating the obtained optical waveguide by the said method, the transmission loss was A, the space | interval of a core part was A, the precision of a core part shape was A, the coating | cover property of a core part was B, and workability was B. FIG.

In addition, the difference in specific refractive index between the core portion and the cladding layer was 0.1% or more.

Example 4 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable dry film (D-4) is transferred onto the surface of the silicon substrate by an atmospheric pressure hot roll pressing method (temperature: 100 ° C), and irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds to photocuring. After the removal, the polyethylene terephthalate film was peeled off to form a lower cladding layer having a thickness of 40 µm. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(2) formation of the core portion

Thereafter, the photocurable dry film (D-5) was transferred onto the lower cladding layer by an atmospheric pressure roll rolling method (temperature: 100 ° C). Thereafter, an ultraviolet ray having a wavelength of 365 nm and an illuminance of 10 mW / cm ² was irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm, and then the polyethylene terephthalate film was peeled off. Next, the board | substrate with the resin composition layer irradiated with ultraviolet-ray was immersed in the developing solution which consists of 1.8 weight% tetramethylammonium hydroxide aqueous solution, the unexposed part of the resin composition layer was melted, and dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(3) formation of the upper cladding layer

The photocurable dry film (D-4) is transferred to the surface of the core part and the lower cladding layer by an atmospheric pressure hot roll pressing method (temperature: 100 ° C.), and UV light having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. After irradiating and photocuring, the polyethylene terephthalate film was peeled off and the upper cladding layer of thickness 40micrometer was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

As a result of evaluating the obtained optical waveguide by the above method, the transmission loss was A, the interval of the core part was A, the precision of the core part shape was A, the coating property of the core part was A, and workability was A. FIG.

In addition, the difference in specific refractive index between the core portion and the cladding layer was 0.1% or more.

Comparative Example 2 Fabrication of Optical Waveguide

(1) Formation of Lower Cladding Layer

The photocurable resin composition 6 was apply | coated by the spin coat method on the surface of a silicon substrate, the ultraviolet-ray of wavelength 365nm and illumination intensity 10mW / cm <^2> was irradiated for 100 second, and the lower cladding layer of thickness 40micrometer was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(2) formation of the core portion

Thereafter, the photocurable dry film (D-6) was transferred onto the lower cladding layer by an atmospheric pressure roll rolling method (temperature: 100 ° C). Thereafter, an ultraviolet ray having a wavelength of 365 nm and an illuminance of 10 mW / cm ² was irradiated and cured for 100 seconds through a photomask having a line-shaped pattern having a width of 30 µm, and then the polyethylene terephthalate film was peeled off. Subsequently, the substrate having the resin composition layer irradiated with ultraviolet rays was immersed in a developer composed of an aqueous 1.8 wt% tetramethylammonium hydroxide solution to dissolve the unexposed portion of the resin composition layer and then dried. In this way, the core part which has a 30-micrometer-wide line pattern was formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

(3) formation of the upper cladding layer

The photocurable resin composition 6 was applied to the surface of the core portion and the lower cladding layer by spin coating, and the upper cladding layer having a thickness of 40 μm was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 10 mW / cm ² for 100 seconds. Formed. Subsequently, it heated at 150 degreeC for 60 minutes, and thermosetted.

As a result of evaluating the obtained optical waveguide by the above method, the transmission loss was A, the spacing of the core portion was B, the precision of the core portion shape was B, the coverability of the core portion was C, and the workability was B.

The carboxyl group-containing unsaturated resin (A) contained in the photocurable resin composition for optical waveguide formation of the present invention can be produced simply and easily by reacting the carboxyl group-containing resin (a) with an epoxy group-containing unsaturated compound (b). .

Moreover, since reaction of a carboxyl group and an epoxy group is used, reactivity is high and a carboxyl group and an unsaturated group can be introduce | transduced surely in resin (A).

Moreover, since the resin (A) which has an ester bond can be obtained by the said reaction, and the coating film which consists of the resin composition of this invention containing this resin (A) is excellent in workability, mechanical characteristics, etc., the resin composition of this invention Is suitable for formation of a dry film.

Moreover, when an aromatic ring is introduce | transduced into resin (A), the resin composition of this invention containing this resin (A) can form the film with high refractive index.

When the photocurable resin composition for optical waveguide formation or the photocurable dry film for optical waveguide formation of this invention is used, the outstanding optical waveguide can be formed.

The optical waveguide of the present invention can be suitably used for coupling optical devices such as optical integrated circuits, optical modulators, optical switches, optical connectors, optical branch couplings, thin film devices, and the like to optical fibers.

Claims (5)

Carboxyl group-containing unsaturated resin (A) obtained by making carboxyl group-containing resin (a) and an epoxy-group-containing unsaturated compound (b) react; And Solvent (B); The photocurable resin composition for optical waveguide formation containing the above. The method of claim 1, The composition further contains a radical photopolymerization initiator Photocurable resin composition for optical waveguide formation. The photocurable dry film for optical waveguide formation formed with the photocurable resin composition for optical waveguide formation of Claim 1. An optical waveguide composed of a lower cladding layer (I), a core portion (II), and an upper cladding layer (III), at least one of which is formed from the photocurable resin composition for optical waveguide formation according to claim 1 Waveguide. An optical waveguide composed of a lower cladding layer (I), a core portion (II), and an upper cladding layer (III), at least one of which is formed of a photocurable dry film for forming an optical waveguide according to claim 3 Waveguide.