JP2020186278A - Photocurable composition and photocurable composition for optical waveguide - Google Patents

Abstract

To provide a photocurable composition that can form a self-forming optical waveguide using low-energy near infrared radiation.SOLUTION: An photocurable composition contains a photocurable bifunctional (meth) acrylate compound such as ethoxylated bisphenol A di(meth) acrylate, a radical generator such as an organic boron salt compound, a tertiary amine compound such as methyl diethanolamine, and a near-infrared photosensitive dye such as a diimonium dye.SELECTED DRAWING: None

Description

The present invention relates to photocurable compositions and photocurable compositions for optical waveguides.

An optical communication system via an optical fiber is provided with an optical module connected to both ends of the optical fiber to perform mutual conversion between optical and electric signals. In recent years, an optical module assembly technique using an optical waveguide as an optical transmission medium having the same function as an optical fiber has become common. Further, recently, a technique for forming a self-forming optical waveguide by irradiating a photocurable resin solution with beam-shaped UV light or blue light having a wavelength of about 450 nm (hereinafter, “UV light or the like”) using an optical fiber has been developed. It has been reported. Here, the self-formed optical waveguide is a transparent polymer obtained by continuously growing a polymerization region in a long shape along the traveling direction of light while being confined in the polymer in a photocurable resin. Is. It has a feature that an optical waveguide without axis deviation can be easily formed (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2000-347043 Japanese Unexamined Patent Publication No. 2004-149579

By the way, silicon photonics elements (silicon chips) in which electric elements and optical elements are formed on a silicon substrate are becoming smaller and more precise in addition to the dramatic increase in optical communication speed in recent years. As a result, precision alignment technology is required to connect the silicon chip to the optical fiber or optical module, and the difficulty is increasing.
Therefore, the application of self-forming optical waveguide technology is envisioned as a means for connecting silicon chips to be miniaturized in silicon photonics.
However, since the silicon constituting the silicon chip has light transmission in the near infrared region having a wavelength (λ) of 1000 nm or more, conventionally, an optical waveguide is formed by polymerizing a photocurable resin by irradiation with UV light or the like. The technology is difficult to apply.

An object of the present invention is to provide a photocurable composition capable of forming a self-forming optical waveguide using low energy near infrared rays.

According to the present invention, there is provided a photocurable composition comprising a bifunctional acrylate compound, a radical generator, a tertiary amine compound, and a near-infrared photosensitive dye.
Here, the radical generator is preferably an organoboron salt.
The radical generator is preferably an organoboron ammonium salt.
The near-infrared photosensitive dye preferably has an absorption maximum at a wavelength (λ) of 1000 nm or more.
The near-infrared photosensitive dye is preferably a diimonium dye.
Further, according to the present invention, there is provided a photocurable composition for an optical waveguide, which comprises the above-mentioned photocurable composition.

According to the present invention, a photocurable composition capable of forming a self-forming optical waveguide using low-energy near-infrared rays can be obtained.

It is a figure explaining the process of preparing the substrate for forming an optical waveguide. It is a figure explaining the formation process of the self-forming optical waveguide (LISW). This is the result of the formation of a self-forming optical waveguide (LISW).

Hereinafter, embodiments for carrying out the present invention will be described (hereinafter, embodiments). The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

(Bifunctional acrylate compound)
The bifunctional acrylate compound used in the present embodiment is a compound that undergoes a polymerization reaction and is cured by irradiating with light, and examples thereof include a photocurable bifunctional acrylate compound and a photocurable bifunctional metallilate compound.

Specific examples of the photocurable bifunctional acrylate compound include, for example, 2-hydroxy-3-acryloyloxypropyl methacrylate, polyethylene glycol diacrylate, propoxylated ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A diacrylate, 9,9. -Bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, propoxylated bisphenol A diacrylate, tricyclodecanedimethanol diacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1 , 9-Nonandiol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate and the like.

Specific examples of the photocurable bifunctional methacrylate compound include, for example, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, ethoxylated bisphenol A dimethacrylate, tricyclodecanedimethanol dimethacrylate, 1 .10-Decandiol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, neopentyl glycol dimethacrylate, ethoxylated polypropylene glycol dimethacrylate, glycerin dimethacrylate, polypropylene glycol dimethacrylate, etc. Be done.

These photocurable bifunctional acrylate compounds and photocurable bifunctional methacrylate compounds can be used alone or in combination of two or more. Among these, ethoxylated bisphenol A diacrylate (2,2-bis [4- (acrylicoxypolyethoxy) phenyl] propane) and ethoxylated bisphenol A dimethacrylate (2,2-bis [4- (methacrylicoxypolyethoxy) ethoxy) ) Phenyl] propane) is preferred.

(Radical generator)
The radical generator in the present embodiment is, for example, any one selected from the group consisting of boron compounds, iodonium salts, polyhalogen compounds, organic peroxides, bisimidazoles, titanosen, sulfonic acid derivatives and N-phenylglycine. More than seeds can be mentioned. These radical generators can be used alone or in combination of two or more. Among these radical generators, boron compounds are preferable.
As the boron compound, an organic boron salt is preferable, and among them, an organic boron ammonium salt composed of an ammonium cation represented by the following general formula (1) and an organic boron anion can be mentioned.

Here, in the formula (1), R ¹ is independently selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, and an alicyclic group. Further, R ² is independently selected from the group consisting of an alkyl group, an aryl group, an allyl group, an aralkyl group, an alkenyl group, an alkynyl group, and an alicyclic group.
Typical examples of alkyl groups are methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group and stearyl group. Group etc. can be mentioned. The alkyl group may be substituted with, for example, one or more halogen groups, cyano groups, acyloxy groups, acyl groups, alkoxy groups, or hydroxyl groups.

Typical examples of aryl groups are phenyl group, p-tolyl group, xsilyl group, mesityl group, cumenyl group, p-methoxyphenyl group, naphthyl group, 2,4-bis (trifluoromethyl) phenyl group, p. -Fluorophenyl group, p-chlorophenyl group, p-bromophenyl group and the like can be mentioned. Typical examples of the aralkyl group include a benzyl group, p-methylbenzyl, p-methoxybenzyl and the like. Typical examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 1-butenyl group and the like. Typical examples of the alkynyl group include an ethenyl group, a 2-tert-butylethenyl group, a 2-phenylethenyl group and the like. Moreover, typical examples of an alicyclic group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and the like.

Specific examples of the ammonium cation include tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetraisopropylammonium, tetrabutylammonium, tetra-sec-butylammonium, tetra-tert-butylammonium, tetrapentylammonium, and tetraisopentyl. Alkyl group-containing ammonium cations such as ammonium, tetraneopentylammonium, tetra-tert-pentylammonium;

Hydrogen-containing ammonium cations such as tetrahydrogenammonium, trimethylhydrogenammonium, triethylhydrogenammonium, tripropylhydrogenammonium, tripropylhydrogenammonium, tributylhydrogenammonium, tripentylhydrogenammonium;

Benzyl group-containing ammonium cations such as benzyltrimethylammonium, benzyltriethylammonium, benzyltripropylammonium, benzyltributylammonium, benzyltripentylammonium, phenyltrimethylammonium, phenyltriethylammonium, phenyltripropylammonium, phenyltributylammonium, phenyltripentylammonium, etc. ;

Vinyl group-containing ammonium cations such as trimethylvinylammonium, triethylvinylammonium, tripropylvinylammonium, tributylvinylammonium, and trypentylvinylammonium;

Allyl group-containing ammonium cations such as trimethylallylammonium, triethylallylammonium, tripropylallylammonium, tributylallylammonium, trypentylallylammonium, dimethyldialylammonium, diethyldiallylammonium, dipropyldialylammonium, dibutyldialylammonium, dipentyldiallylammonium;

(2-methoxyethoxymethyl) trimethylammonium, (2-methoxyethoxymethyl) triethylammonyl, (2-methoxyethoxymethyl) tripropylammonium, (2-methoxyethoxymethyl) tributylammonium, (2-methoxyethoxymethyl) tripentyl Alkyl alkyl group-containing ammonium cations such as ammonium; hexamesonium, decamesonium, ferrocenylmethyltrimethylammonium, ferrocenylmethyltriethylammonium, ferrocenylmethyltripropylammonium, ferrocenylmethyltributylammonium, ferrocenylmethyltri Examples include pentylammonium.

Further, cholines such as choline, chlorocholine, acetylcholine, acetylthiocholine, butyrylcholine, butyrylthiocholine, benzoylcholine, benzoylthiocholine, metacholine, metacloylcholine, lauroylcholine and the like can be mentioned.

Examples of the organoboron anion include triarylmonoalkylboron anions. Specific compounds include, for example, triphenylmethylborate, triphenylethylborate, triphenylpropylborate, triphenylisopropylborate, triphenylbutylborate, triphenylisobutylborate, triphenyl-sec-butylborate, triphenyl-. tert-butylborate, tris (p-tolyl) butylborate, trimesityl butylborate, tris (p-anisyl) butylborate, tris (2,4,5-trifluorophenyl) butylborate, tris (pentafluorophenyl) butyl Butyl and the like can be mentioned.

The amount of the radical generator to be blended in the photocurable composition to which the present embodiment is applied is preferably 0.1 part by weight or more of the radical generator with respect to 100 parts by weight of the bifunctional acrylate compound in the photocurable composition. Is 0.3 parts by weight or more. However, it is usually 10 parts by weight or less, preferably 5 parts by weight or less.

(Primary amine compound)
The tertiary amine compound in the present embodiment is a compound that promotes photopolymerization of a photocurable bifunctional acrylate compound in combination with the above-mentioned radical generator.
Specific examples of the tertiary amine compound include triethanolamine, methyldiethanolamine, triisopropanolamine, diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, aminoethylethanolamine, n-aminopiperazin, diaminodiphenylmethane, dimethylaniline, and the like. Diethylaniline, dimethyltoluidine, diethyltoluidine, dimethylaminoethyl methacrylate, 2.4.6-simmethylaminomethylphenyl, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 2-dimethylaminobenzoic acid Examples thereof include ethyl, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate and the like.

These tertiary amine compounds can be used alone or in combination of two or more. Among these, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate and the like are preferable.

In the photocurable composition to which the present embodiment is applied, the irradiation energy of near infrared rays required for the photocuring reaction of the bifunctional acrylate compound contained in the composition by using the radical generator and the tertiary amine compound in combination. Is significantly reduced (about 1/5000) as compared with the case where the tertiary amine compound is not used in combination.
The blending amount of the tertiary amine compound is 0.1 part by weight or more, preferably 0.3 part by weight or more, based on 100 parts by weight of the bifunctional acrylate compound in the photocurable composition. However, it is usually 5 parts by weight or less, preferably 3 parts by weight or less. If the amount of the tertiary amine compound is excessively small, high-energy light irradiation tends to be required for the polymerization reaction of the bifunctional acrylate compound.

(Near infrared photosensitive dye)
In the present embodiment, the near infrared ray means light (electromagnetic wave) having a maximum absorption wavelength region of λ700 nm to 2500 nm. The near-infrared photosensitive dye used in the present embodiment is preferably a dye having a maximum absorption wavelength in the range of λ900 nm to 1800 nm, and further, a dye having a maximum absorption wavelength in the range of λ1000 nm to 1800 nm. Is preferable.

Examples of the type of near-infrared absorbing dye include a dye containing at least one type (ion site) selected from an anion site and a cation site in the molecule. Specifically, for example, cyanine pigment, indocyanine pigment, thiocyanine pigment, polymethine pigment, phthalocyanine pigment, pyrylium pigment, thiopyrylium pigment, anthraquinone pigment, aminium pigment, iminium pigment, diimmonium pigment, azulenium pigment, croconium pigment, thiol nickel complex salt. Examples thereof include pigments, squarylium pigments, naphthoquinone pigments, flugide pigments, pyrolopyrrole pigments, dithiolene pigments, porphyrin pigments, azo pigments, triarylmethane pigments, and perylene pigments. These near-infrared absorbing dyes can be used alone or in combination of two or more. Among these, the diimonium pigment is preferable.

Here, the diimonium dye is preferably a compound represented by the formula (2).

Here, in equation (2), X ⁻ is a counter anion. R ³ independently represents an alkyl group having 1 to 7 carbon atoms or an alkoxyalkyl group having 1 to 5 carbon atoms.

Examples of counter anions include halogen ions (Cl ⁻ , Br ⁻ , I ⁻ ), p-toluenesulfonic acid ions, ethyl sulfate ions, SO ₄ ^2- , SbF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , B ( ^{_{C 6 F 5) 4 -,}} ClO 4 -, tris (halogenoalkyl alkylsulfonyl) methide anion _{(e.g., (CF 3 SO 2) 3} C -), di (halogenoalkyl) imide anion (e.g. _(CF 3 _{SO 2) 2} N ⁻ ), tetracyanoborate anion and the like can be mentioned. Among these, tris (trifluoromethanesulfonyl) methideanion is preferable.

Specific examples of the alkyl group having 1 to 7 carbon atoms in ^{R 3} of formula (2), for example, a methyl group, an ethyl group, n- propyl group, iso- propyl, n- butyl, iso- butyl group, sec-butyl group, t-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, 1,2-dimethyl-propyl group, n-hexyl group, cyclohexyl group, 1,3-dimethyl-butyl group , 1-iso-propylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group, 2-methi-1-iso-propylpropyl group, 1-ethyl-3-methylbutyl group , N-octyl group, 2-ethylhexyl group, 3-methyl1-iso-propylbutyl group, 2-methyl-1-iso-propyl group and the like. Among these, an ethyl group, an n-butyl group and an isobutyl group are preferable.

As the alkoxyalkyl group having 1 to 5 carbon atoms in R ³ of formula (2), methoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, n- butoxyethyl, 3-methoxypropyl group, 3- Examples thereof include an ethoxypropyl group, a methoxyethoxymethyl group, an ethoxyethoxyethyl group, a dimethoxymethyl group, a dietoxymethyl group, a dimethoxyethyl group and a diethoxyethyl group, and examples of the alkyl halide group include a chloromethyl group and 2, Examples thereof include 2,2-trichloroethyl group, trifluoromethyl group and 1,1,1,3,3,3-hexafluoro2-propyl group. It is preferably a methoxyethyl group, an ethoxyethyl group, a propoxyethyl, an n-butoxyethyl group, and particularly preferably a methoxyethyl group.

Examples of the substituent which may have an alkyl group having 1 to 7 carbon atoms in R ³ of formula (2), for example, an alkoxyalkyl group in which the hydrogen atom of unsubstituted alkyl group described above is substituted with an alkoxy group, Examples thereof include an alkoxyalkoxyalkyl group substituted with an alkoxyalkoxy group, an alkoxyalkoxyalkoxyalkyl group substituted with an alkoxyalkoxyalkoxy group, and an alkyl halide group in which the hydrogen atom of the unsubstituted alkyl group is substituted with halongen, amino. Examples thereof include an aminoalkyl group substituted with a group, an alkylaminoalkyl group or a dialkylaminoalkyl group substituted with an alkylamino group, an alkoxycarbonylalkyl group, an alkylaminocarbonylalkyl group, an alkoxysulfonylalkyl group, a cyanoalkyl group and the like. ..

Formula Examples of the substituent which may have an alkoxyalkyl group having 1 to 5 carbon atoms for R ³ in (2), for example, alkoxyalkoxy groups in which the hydrogen atom of the unsubstituted alkoxy group described above is substituted in the alkoxy group , Alkoxyalkoxyalkoxy group substituted with alkoxyalkoxy group, alkoxyalkoxyalkoxyalkoxy group substituted with alkoxyalkoxyalkoxy group, etc., and a halogenated alkoxy group in which the hydrogen atom of the unsubstituted alkyl group is substituted with halongen, Examples thereof include an aminoalkoxy group substituted with an amino group, an alkylaminoalkoxy group or a dialkylaminoalkoxy group substituted with an alkylamino group, an alkoxycarbonylalkoxy group, an alkylaminocarbonylalkoxy group, and an alkoxysulfonylalkoxy group.

The blending amount of the near-infrared photosensitive dye in the photocurable composition to which the present embodiment is applied is 0.1 weight by weight of the near-infrared photosensitive dye with respect to 100 parts by weight of the bifunctional acrylate compound in the photocurable composition. Parts or more, preferably 0.3 parts by weight or more. However, it is usually 10 parts by weight or less, preferably 5 parts by weight or less.

<Other compounding agents>
A solvent, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, an antioxidant and other additives can be added to the photocurable composition to which this embodiment is applied, if necessary.

The photocurable composition to which the present embodiment is applied contains a bifunctional acrylate compound, a radical generator, a tertiary amine compound, and a combination initiator composed of a near-infrared photosensitive dye, and has a wavelength (λ) of 1000 nm. It is possible to form a self-forming optical waveguide by irradiating the above low-energy near-infrared light. That is, the threshold value of photocuring is lowered as compared with the technique for forming a self-formed optical waveguide that has conventionally used UV light or the like, and the optical waveguide can be formed by the low output light used for optical communication.
Then, by using near-infrared light having a wavelength (λ) of 1000 nm or more, it becomes possible to form an interconnection in silicon photonics using silicon having transparency in this wavelength region.
The use of continuous laser light (CW) in the near-infrared region also makes high-power pulses, for example, when forming an interconnection between a small-diameter single-mode optical fiber and an input / output silicon nanowire waveguide. Compared with the case of using laser light, damage to silicon nanowires can be avoided.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to Examples. In addition, all parts and% in Examples and Comparative Examples are based on weight.

[Example 1]
The photocurable composition I is prepared by the following operation, and then the prepared photocurable composition I is irradiated with near infrared rays to form a self-forming optical waveguide.
<Preparation of photocurable composition>
The following bifunctional acrylate compound (component 1), radical generator (component 2), tertiary amine compound (component 3) and near-infrared photosensitive dye (component 4) are blended to prepare a photocurable composition I. ..

(Photocurable Composition I)
(Component 1) Photocurable bifunctional acrylate compound (bifunctional acrylate compound)
2,2-bis [4- (acrylic oxydiethoxy) phenyl] propane (Nichumura Chemical Industry Co., Ltd. ethoxylated bisphenol A diacrylate: A-BPE-4) 100 parts (component 2) Radical generator tetra-n -Butylammonium triphenyl-n-butylborate (organic boron ammonium complex manufactured by Showa Denko Co., Ltd .: P3B) 0.6 part (component 3) tertiary amine compound N-methyldiethanolamine (manufactured by Sigma-Aldrich: MDEA) 0. 8 parts (component 4) Near infrared photosensitive dye Diimonium dye (manufactured by Nippon Carlit Co., Ltd .: CIR-960) 0.7 parts

<Preparation procedure>
The photocurable composition I is prepared according to the following procedure.
(Procedure 1)
A photocurable bifunctional acrylate compound (A-BPE-4), a radical generator (P3B), and a diimonium-based dye (CIR-960) are placed in a sample tube bottle to prepare a mixed solution. At this time, the weight of the photocurable bifunctional acrylate compound (A-BPE-4) in the mixed solution is about 1,000 mg.
As the sample tube bottle used, Labran Sample Tube Bottle No. 1 manufactured by AS ONE Corporation. 2 (5 cc, product number 9-851-04) is used.
(Procedure 2)
Next, a stirrer (15 mm × φ5 mm) is placed in a sample tube bottle, and the above mixed solution is stirred at room temperature at 500 rpm for 12 hours or more.
(Procedure 3)
Subsequently, after stirring for 12 hours or more, the tertiary amine compound (MDEA) is added to the mixed solution in the sample tube bottle, and the mixed solution is further stirred at room temperature at 500 rpm for 3 hours to 4 hours.
(Procedure 4)
Then, the stirring is stopped, and the mixed solution is allowed to stand under reduced pressure using a vacuum desiccator and a vacuum pump to defoam.

<Manufacturing of self-formed optical waveguide>
(Substrate for forming optical waveguide)
FIG. 1 is a diagram illustrating a step of preparing a substrate 10 for forming an optical waveguide.
First, as shown in FIG. 1A, the optical fiber 12 is fixed to one side of the slide glass 11 (width 26 mm × length 76 mm) with the adhesive 14. Next, the tip portion 13 of the optical fiber 12 is fixed to the upper surface of the slide glass 11 using the adhesive tape 15.
As the slide glass 11, S1112 (white edge polishing No. 2) manufactured by Matsunami Glass Industry Co., Ltd. is used. The adhesive 14 uses a two-component curable epoxy adhesive (Quick 5 manufactured by Konishi Co., Ltd.), and the adhesive tape 15 uses Capton tape (Nitto Denko Co., Ltd. P-221AMB). The optical fiber 12 will be described later.

Next, as shown in FIG. 1B, two strip-shaped cover glasses 16 and so as to be parallel to the tip 13 on both sides of the tip 13 of the optical fiber 12 fixed to the upper surface of the slide glass 11. Each of 16 is fixed with an adhesive. The strip-shaped cover glasses 16, 16 (manufactured by Muto Chemical Co., Ltd.) are 5 mm wide and 18 mm long, and have a predetermined thickness (0.12 mm to 0.17 mm) so that a gap is formed on the slide glass 11. )have.

Subsequently, as shown in FIG. 1 (c), the cover glass 17 (width 18 mm × length 18 mm) is placed on the two strip-shaped cover glasses 16 and 16 fixed to both ends of the slide glass 11 so as to cover them. , Thickness 0.12 mm to 0.17 mm) and fix. As a result, a gap (cell-like region) is formed between the slide glass 11 and the two strip-shaped cover glasses 16, 16 and the cover glass 17, and as will be described later, a photocurable composition prepared in advance is formed in this gap. A mixture of I is injected.

(Self-forming optical waveguide forming process)
FIG. 2 is a diagram illustrating a step of forming a self-forming optical waveguide (LISW) 30. Here, the display of the adhesive 14 and the adhesive tape 15 is omitted.
As shown in FIG. 2A, a photocurable composition is formed in a cell-like region 20 (gap) formed between the slide glass 11 and the two strip-shaped cover glasses 16, 16 and the cover glass 17 by a capillary effect. Fill the solution of I and fully immerse the tip 13 of the optical fiber 12. Further, the solution of the photocurable composition I is subjected to UV irradiation (Pre-UV irradiation: intensity 40 mW / cm ² , 60 seconds to 120 seconds, 80 seconds in this example) to partially apply the photocurable composition I. Polymerizes to increase the viscosity of the solution. The UV irradiator used for UV irradiation is Spot Cure SP-9 (irradiation unit AF-102NQ-X) manufactured by Ushio, Inc. As the UV illuminometer, UIT-250 manufactured by Ushio, Inc. is used.

Subsequently, as shown in FIG. 2B, near-infrared laser light is emitted from the tip portion 13 of the optical fiber 12 into the solution of the photocurable composition I for a predetermined time. The photocurable composition I is gradually cured by the emitted laser light to form an axial self-forming optical waveguide 30. At this time, since the viscosity of the solution of the photocurable composition I is increased in advance by UV irradiation, bending of the self-formed optical waveguide 30 is prevented.

(Laser light source)
In this embodiment, the self-formed optical waveguide 30 is formed by irradiating three types (1070 nm, 1311 nm, 1550 nm) of near-infrared laser light having different wavelengths (λ). The laser light sources used are as follows.
(A) Center wavelength (λ) 1070 nm: LDS1003 series manufactured by Precise Gauge Co., Ltd. (b) Center wavelength (λ) 1311 nm: LDS1003 series manufactured by Precise Gauge Co., Ltd. (c) Wavelength (λ) 1550 nm: Key Site Technology N7711A-210 (tunable wavelength)
As the optical fiber 12 fixed to the slide glass 11 of the optical waveguide forming substrate 10, a single-mode optical fiber with a single-ended FC / PC connector (SMF-28-J9 manufactured by Thorlabs) is used. The laser light source and the optical fiber 12 are connected by an FC / PC connector.

FIG. 3 shows the result of forming a self-formed optical waveguide (LISW). In FIG. 3A, a long self-formed optical waveguide (LISW) is formed from the tip portion 13 of the optical fiber by irradiation with a near-infrared laser beam having a center wavelength (λ) of 1070 nm and an output of 1 μW for 1 minute. .. The self-formed optical waveguide (LISW) formed has a diameter of 10 μm and a length of 0.86 mm.
In FIG. 3B, a long self-formed optical waveguide (LISW) is formed from the tip portion 13 of the optical fiber by irradiation with a near-infrared laser beam having a center wavelength (λ) of 1310 nm and an output of 3 mW for 1 minute. .. The self-formed optical waveguide (LISW) formed has a diameter of 10 μm and a length of 1.7 mm.
In FIG. 3C, a long self-formed optical waveguide (LISW) is formed from the tip portion 13 of the optical fiber by irradiating with a near-infrared laser beam having a center wavelength (λ) of 1550 nm and an output of 20 mW for 2.5 minutes. ing. The self-formed optical waveguide (LISW) formed has a diameter of 20 μm and a length of 2.5 mm.

[Comparison example]
The following photocurable composition II is prepared, and the photocurable composition II is irradiated with near-infrared laser light using the optical waveguide forming substrate 10 prepared in FIG. 1 (c) to obtain a self-forming optical waveguide. Form.
(Component a) 100 parts of bifunctional acrylate compound 2,2-bis [4- (acrylic oxydiethoxy) phenyl] propane (Ethoxylated bisphenol A diacrylate manufactured by Shin Nakamura Chemical Industry Co., Ltd .: A-BPE-4)
(Component b) Radical generator 0.6 part Tetra-n-butylammonium triphenyl-n-butylborate (Organoboron ammonium complex manufactured by Showa Denko KK: P3B)
(Component c) 0.7 parts of diimonium dye (manufactured by Japan Carlit Co., Ltd .: CIR-960)

When the photocurable composition II is irradiated with a near-infrared laser light having a center wavelength (λ) of 1070 nm for 1 minute, a long self-formed optical waveguide similar to that in Example 1 (FIG. 3A) is formed. In order to do so, a laser beam having an output of 5 mW was required.
From this result, the photocurable composition I (Example 1) to which the present embodiment is applied has a low output of about (1/5000) as compared with the photocurable composition II prepared in Comparative Example. It can be seen that a self-forming optical waveguide is formed by the near-infrared laser light of.

10 ... Optical waveguide forming substrate, 11 ... Slide glass, 12 ... Optical fiber, 13 ... Tip, 14 ... Adhesive, 15 ... Adhesive tape, 16 ... Strip-shaped cover glass, 17 ... Cover glass, 20 ... Cell-like region, 30 ... Self-formed optical waveguide

Claims (6)

With a bifunctional acrylate compound
Radical generator and
With a tertiary amine compound
Near-infrared photosensitive dye and
A photocurable composition comprising. The photocurable composition according to claim 1, wherein the radical generator is an organic boron salt. The photocurable composition according to claim 1 or 2, wherein the radical generator is an organoboron ammonium salt. The photocurable composition according to any one of claims 1 to 3, wherein the near-infrared photosensitive dye has an absorption maximum at a wavelength of λ1000 nm or more. The photocurable composition according to any one of claims 1 to 4, wherein the near-infrared photosensitive dye is a diimonium dye. A photocurable composition for an optical waveguide, which comprises the photocurable composition according to claims 1 to 5.