JP2007302581A - Bisoxetane compound, method for producing the same, and optical waveguide using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new oxetane compound imparting a polymer excellent in thick film forming property, curing property, heat resistance, etc., and to provide a method for producing the same and to provide an optical waveguide using the same. <P>SOLUTION: The bisoxetane compound is produced by reacting phenols with cesium salt to form a cesium phenolate and then reacting with sulfonic acid ester to obtain the bisoxetane compound represented by general formula (1). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel bisoxetane compound having an oxetane ring capable of cationic polymerization, a production method thereof, and an optical waveguide using the same. Specifically, a photocurable resin and a thermosetting resin using the compound are excellent in heat resistance, mechanical properties, low water absorption, coating film flatness, adhesion, etc. The present invention relates to an optical waveguide that can be used on various integrated circuits and optical wiring boards in the field of communication and information processing.

  A method for producing an optical waveguide using a polymerizable polymer compound is easier than a quartz-based optical waveguide, and therefore can be reduced in price. Moreover, since it has a softness | flexibility depending on the material, it can be used for various uses as a film-form optical waveguide, and the use expansion is anticipated.

  As a method for producing an optical waveguide using such a polymer compound, a polymerization initiator having a response reaction to light is blended in a polymerizable monomer or oligomer, and reacted with the monomer or oligomer by light irradiation. And a method of patterning the core portion by curing only the light irradiated portion.

  As the polymerizable monomer, an oxetane compound is a monomer capable of photoinitiated cationic polymerization or curing, and has attracted attention in recent years. Many monofunctional and polyfunctional oxetane compounds have been developed, Accordingly, various methods for synthesizing oxetane compounds have been proposed. It is known that this oxetane compound is more likely to proceed and the degree of polymerization, that is, the molecular weight, is easier to improve than an epoxy compound that is the same ring-opening polymerizable compound.

  As such an oxetane compound, for example, also in patent literature, an oxetane compound represented by the following general formula (4) has been proposed (see Patent Literature 1).

  Furthermore, biphenyl derivatives having an oxetane ring represented by the following general formula (5) and general formula (6) have also been proposed (see Patent Documents 2 and 3).

The above compounds are usually obtained by synthesizing an oxetane sulfonic acid ester and a corresponding dihydric phenol compound in the presence of an alkali metal such as sodium hydroxide or potassium hydroxide as a base. can get. In the synthesis, a phase transfer catalyst such as a quaternary ammonium salt is also used as necessary to increase the yield of the compound. Furthermore, the oxetane compound has been conventionally used for materials such as paints and adhesives in order to improve heat resistance, adhesion, etc. In recent years, it has also been proposed to use it as a material for forming optical waveguides. (See Patent Documents 4 and 5). The optical waveguide is incorporated in an optical waveguide device, an optical integrated circuit, and an optical wiring board, and is widely used in the fields of optical communication, optical information processing, and other general optics.
JP-A-6-16804 JP-A-11-106380 JP 2001-31665 A JP 2000-356720 A JP 2003-147045 A

  However, since most of these oxetane compounds exhibit a low-viscosity liquid, for example, when used as a material for forming optical waveguides, it is difficult to stably cure and produce the same shape. Is not stable, and a thick film cannot be easily formed. For example, among the oxetane compounds, the biphenyl derivative is a compound having a low molecular weight and thus has a low viscosity. For example, when forming a film on a substrate, it has a difficulty in forming a thick film. Moreover, since it is bifunctional, there also exists a fault that hardening requires time. Further, as described above, there is a problem that it is difficult to obtain desired thick film formability, curability and the like with respect to other oxetane compounds.

  Furthermore, the conventional method for synthesizing an oxetane compound also has a problem that the introduction of an oxetanyl group does not proceed quantitatively and the yield of the target oxetane compound is low. In addition, since a compound having an unreacted hydroxyl group is generated as a by-product, a complicated operation is often involved before obtaining the target oxetane compound.

  The present invention has been made in view of such circumstances, a novel bisoxetane compound capable of producing a polymer excellent in thick film forming property, curability, heat resistance, and the like, a method for producing the same, and a method using the same The purpose is to provide an optical waveguide.

In order to achieve the above object, the first gist of the present invention is a bisoxetane compound represented by the following general formula (1).

Further, the present invention is a process for producing a bisoxetane compound according to the first aspect, wherein a phenol represented by the following general formula (2) is converted to cesium phenolate with a cesium salt, and then the following general formula: A method for producing a bisoxetane compound that is reacted with a sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane represented by (3) is a second gist.

  Furthermore, the present invention is an optical waveguide comprising a substrate and a clad layer formed on the substrate, wherein a core portion that propagates an optical signal in a predetermined pattern is formed in the clad layer, An optical waveguide in which at least one of the cladding layer and the core part is formed of the resin composition containing the bisoxetane compound of the first aspect is a third aspect.

  The inventors of the present invention seek an oxetane compound that is excellent in heat resistance, mechanical properties, etc., and that can produce a polymer that can be effectively used as a material for paints, coating materials, adhesives, lenses, optical waveguides, etc. We studied earnestly. As a result of synthesizing various compounds having a special structure and repeating experiments, when the novel oxetane compound represented by the general formula (1) is used, the intended purpose as described above is achieved. As a result, the present invention has been reached. That is, the oxetane ring of the novel compound has fast curability and the cured product forms a high-density network structure, and thus has excellent heat resistance and the like. In addition, the above-mentioned novel compounds are not low molecular weight like existing compounds, but have high molecular weights to some extent, so that they have high viscosity and are advantageous when forming thick films, especially optical waveguides (cladding layers and core parts). When it is used as a forming material, it becomes easy to cure and form the same shape in a stable manner, so that the effects such as stabilization of the waveguide characteristics can be obtained. On the other hand, the present inventors have also conducted research on a synthesis method capable of synthesizing the novel compound with high yield. As a result, the phenol represented by the general formula (2) and the sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane represented by the general formula (3), in particular, a cesium salt as a base. As a result of using and reacting under predetermined conditions, it was also found that the target novel compound can be synthesized in high yield.

  Thus, the present invention relates to a bisoxetane compound represented by the general formula (1). This compound does not have a low molecular weight like existing compounds but has a high molecular weight to some extent, so that it has a high viscosity and can easily form a thick film. In addition, the oxetane ring in the molecule has the property of being rapidly cured by light or heat. Therefore, the photocurable resin composition and thermosetting resin composition using the bisoxetane compound of the present invention are excellent in curability, heat resistance, toughness and mechanical properties, and have low water absorption, coating flatness and adhesion. Since the use of a polymerization initiator can be reduced due to its high reactivity and high reactivity, it is also highly transparent, for example, as a forming material for paints, coating materials, adhesives, optical lenses, optical waveguides, etc. Useful.

  Then, when synthesizing the bisoxetane compound, the specific oxetane sulfonic acid ester and the specific phenol are reacted with each other under a predetermined condition using a cesium salt as a base. Can be synthesized in a high yield without accompanying.

  Further, when at least one of the cladding layer and the core portion in the optical waveguide is formed of the resin composition containing the bisoxetane compound represented by the general formula (1), the cured product is stably cured in the same shape. And stable waveguide characteristics can be obtained.

  Next, an embodiment of the present invention will be described.

The bisoxetane compound of the present invention is a compound represented by the following general formula (1), and has a structure having two oxetane rings in one molecule. In the general formula (1), R _{1 to} R ₆ are each independently a hydrogen atom or a methyl group, for example, preferably a hydrogen atom, as shown below. In the general formula (1), R ₇ is a hydrogen atom or an alkyl group having 1 to 7 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Group, an ethyl group.

  The bisoxetane compound represented by the general formula (1) includes a phenol represented by the following general formula (2) and a 3-alkyl-3-hydroxymethyloxetane represented by the following general formula (3). It can manufacture by making these sulfonic acid ester and a base into a synthetic raw material, and making these react.

  Here, as the base, a conventionally known alkali metal (sodium hydroxide, potassium hydroxide, etc.) may be used. In the present invention, the bisoxetane is particularly used when a cesium salt is used as the base. Since the compound can be synthesized in a high yield without complicated operations, it is preferable. In this case, for example, synthesis of each raw material is performed by, for example, (i) converting phenols to cesium phenolate with a cesium salt and then reacting with oxetane sulfonate, or (ii) oxetane sulfonate and phenol. The reaction is carried out in the presence of a cesium salt. Preferably, it is carried out according to the procedure (i) above. The above synthesis is usually carried out in an organic solvent (reaction solvent), and after the reaction is completed, water or the like is added to the reaction solution to form an aqueous phase and an organic phase, and extraction from the organic phase is performed for the purpose. A bisoxetane compound can be obtained.

  Examples of the cesium salt include cesium carbonate, cesium hydroxide, cesium fluoride, cesium formate, and the like. Among these, cesium carbonate is preferably used because the target bisoxetane compound can be obtained in a higher yield.

  And it is preferable to set the usage-amount of the said cesium salt to 0.8-2.0 mol with respect to 1 mol of phenolic hydroxyl groups of the phenols represented by the said General formula (2), More preferably, 1 The range is from 0.0 to 1.5 mol.

  Examples of the phenols represented by the general formula (2) include 1,3-bis (4-hydroxyphenoxy) benzene, 1,4-bis (4-hydroxyphenoxy) benzene, and 1,3-bis (3-methyl). -4-hydroxyphenoxy) benzene, 1,3-bis (3-methyl-4-hydroxyphenoxy) toluene, 1,4-bis (3-methyl-4-hydroxyphenoxy) benzene, 1,4-bis (3- Methyl-4-hydroxyphenoxy) toluene, 1,3-bis (3,5-dimethyl-4-hydroxyphenoxy) -p-xylene, 1,4-bis (3,5-dimethyl-4-hydroxyphenoxy) -p -Xylene and the like. These may be used alone or in combination of two or more.

  Specific examples of the sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane represented by the general formula (3) used together with the phenols include 2- (3-oxetanyl) propyl mesylate, 2 Examples include-(3-oxetanyl) propylphenylsulfonylate, 2- (3-oxetanyl) propyl tosylate, 2- (3-oxetanyl) butyl mesylate, 2- (3-oxetanyl) butyl tosylate, and the like. These may be used alone or in combination of two or more.

  The sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane represented by the general formula (3) is, for example, organic synthesis vol. 1 [Organic Synthesis, Collective vol. 1, pp. 145 (1941)]. It can be synthesized according to the method described in 1.

  Furthermore, the usage-amount of the sulfonic acid ester of 3-alkyl-3-hydroxymethyl oxetane represented by the said General formula (3) is 1 mol of phenolic hydroxyl groups of the phenol represented by the said General formula (2). Is preferably set to 1.5 to 2.0 mol, and more preferably in the range of 1.0 to 1.5 mol.

  And at the time of manufacture of the bisoxetane compound of this invention, it is preferable to set the reaction temperature in the case of the synthesis | combination to 0-120 degreeC, More preferably, it is the range of 60-100 degreeC. Moreover, when phenols are cesium phenolated in advance with a cesium salt, the reaction temperature in the cesium phenolate is preferably set to 0 to 120 ° C, more preferably in the range of 40 to 100 ° C. . And the pressure in these reactions is not specifically limited, Any of a normal pressure, pressurization, and pressure reduction may be sufficient. The reaction atmosphere may be a nitrogen atmosphere or an air atmosphere, and is not particularly limited.

  In addition, when synthesizing the bisoxetane compound of the present invention, an alkali metal such as sodium or potassium, an alkali metal hydride such as lithium hydride or sodium hydride, sodium hydroxide, potassium hydroxide, etc. You may add alkali metal carbonates, such as an alkali metal hydroxide and sodium carbonate, as a raw material for synthesis suitably.

  Moreover, you may add a quaternary ammonium salt, a quaternary phosphonium salt, etc. as a phase transfer catalyst between an aqueous phase and an organic phase as needed. The quaternary ammonium salt is not particularly limited, and examples thereof include tetraalkylammonium halides such as tetrabutylammonium bromide (TBAB) and tetraethylammonium bromide, and aralkyltrialkylammonium halides such as benzyltrimethylammonium chloride. can give. The quaternary phosphonium salt is not particularly limited, and examples thereof include tetraarylphosphonium halides such as tetraphenylphosphonium bromide.

  Furthermore, when manufacturing the bisoxetane compound of this invention, a reaction solvent is normally used as mentioned above. The reaction solvent is not particularly limited. For example, aromatic hydrocarbons (toluene, xylene, etc.), ethers (tetrahydrofuran, dibutyl ether, etc.), aprotic polar solvents (N-methylpyrrolidone, N-methyl-2- Pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, etc.) are preferably used. These may be used alone or in combination of two or more.

  As described above, bisoxetane compounds synthesized from these raw materials are usually separated into an aqueous phase and an organic phase by adding water and ethyl acetate to the reaction solution, and the organic phase is extracted. The dried product can be recovered by drying with anhydrous magnesium sulfate or the like.

  The bisoxetane compound of the present invention thus obtained can be effectively used as a material for a photocurable resin and a thermosetting resin constituting paints, coating materials, adhesives, lenses, optical waveguides and the like. Can do.

  Among them, an optical waveguide, specifically, as shown in FIG. 1, includes a substrate 1 and a cladding layer 2 formed on the substrate 1, and propagates an optical signal in a predetermined pattern in the cladding layer 2. In the optical waveguide in which the core portion 3 is formed, when at least one of the cladding layer 2 and the core portion 3 is formed of a resin composition containing the bisoxetane compound, the compound has a high molecular weight. The viscosity becomes high, which is advantageous when forming a thick film. In addition, it is possible to obtain an effect such as that the waveguide characteristics can be stably stabilized by being easily cured in the same shape. The clad layer 2 needs to have a refractive index smaller than that of the core portion 3.

  Further, when at least one of the clad layer 2 and the core part 3 is formed of a resin composition containing a compound having an epoxy group or a vinyl ether group together with the bisoxetane compound of the present invention, heat resistance and moisture resistance It is preferable because a cured product having excellent resistance can be obtained and the exposure sensitivity can be improved. Here, as the compound having an epoxy group, any compound can be used as long as it is compatible with the compound represented by the formula (1) of the present invention. Specifically, examples of the epoxy compound having one epoxy group include phenyl glycidyl ether and butyl glycidyl ether, and examples of the epoxy compound having two or more epoxy groups include bisphenol A diglycidyl ether, bisphenoxyethanol full orange glycidyl. Ether, trimethylolpropane triglycidyl ether, bisphenolfluorene tetraglycidyl ether, 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenecarboxylate, 2,2-bis ( An adduct of 1,2-epoxy-4- (2-oxiranyl) cyclohexane with hydroxymethyl) -1-butanol is preferably used. Any compound having a vinyl ether group may be used as long as it is compatible with the compound represented by the formula (1) of the present invention. Specifically, examples of the compound having one vinyl ether group include hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, dodecyl vinyl ether and the like. As the compound having two or more vinyl ether groups, cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether, novolak type divinyl ether and the like are preferably used. And these compounds are used individually or in combination of 2 or more types.

  And the said optical waveguide can be manufactured by passing through a process as shown to Fig.2 (a)-(f), for example. That is, as shown in FIG. 2A, first, a substrate 1 is prepared, and as shown in FIG. 2B, an under cladding layer 2a (a lower portion of the cladding layer 2) is formed on the surface of the substrate 1. Next, as shown in FIG. 2 (c), a layer 3 'made of a resin composition for forming the core portion 3 is formed on the under cladding layer 2a. Then, as shown in FIG. 2 (d), a photomask 9 for exposing a predetermined pattern (optical waveguide pattern) is disposed on the surface of the resin composition layer 3 ′. Irradiate ultraviolet rays, and further heat treatment. Thereafter, the unexposed portion of the resin composition layer 3 ′ is dissolved and removed using a developer to form the core portion 3 as shown in FIG. Then, as shown in FIG. 2 (f), an over clad layer 2 b (an upper part of the clad layer 2) is formed on the core portion 3. Thereby, the target optical waveguide can be obtained.

  Each layer on the substrate 1 can be formed by a conventionally known method such as spin coating or coater. In addition, the optical waveguide can be formed into a film-shaped optical waveguide by peeling off the substrate 1 after being manufactured in this way. In such a configuration, the flexibility becomes excellent.

  Further, the material of the substrate 1 is not particularly limited and is a conventionally known material such as a quartz glass plate, a silicon wafer, a ceramic substrate, a glass epoxy resin substrate, a resin such as a polyimide film or a polyethylene terephthalate (PET) film. Examples thereof include thin and flexible materials such as films, metal foils such as copper foil and stainless steel foil. Although the thickness is also set appropriately, it is usually set in the range of 10 μm to 5 mm.

  The optical waveguide thus obtained is, for example, a straight optical waveguide, a curved optical waveguide, a crossed optical waveguide, a Y-branch optical waveguide, a slab optical waveguide, a Mach-Zehnder optical waveguide, an AWG optical waveguide, a grating, or an optical waveguide lens. Etc. can be used. Optical devices using these optical waveguides include wavelength filters, optical switches, optical splitters, optical multiplexers, optical multiplexers / demultiplexers, optical amplifiers, wavelength converters, wavelength dividers, optical splitters, directional couplers. Furthermore, an optical transmission module in which laser diodes and photodiodes are integrated in a hybrid manner can be used.

  Next, examples will be described. However, the present invention is not limited to these examples.

  First, prior to Examples, 2- (3-oxetanyl) butyl tosylate, which is a sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane, was synthesized as follows.

[Synthesis of 2- (3-oxetanyl) butyl tosylate]
In a 2000 ml three-necked eggplant flask equipped with a thermometer, a condenser, a stirring device and a dropping funnel, 190.65 g (1.0 mol) of p-toluenesulfonic acid chloride and 32.24 g (0.1 mol) of tetramethylammonium bromide And 400 ml of toluene was added, and it cooled to 5 degreeC, stirring in an ice bath. After adding 116.16 g (1.0 mmol) of 3-ethyl-hydroxymethyloxetane to this, 130 ml of 35 wt% sodium hydroxide aqueous solution was dripped over 30 minutes with the dropping funnel. After completion of the dropwise addition, the flask was stirred for 1 hour at the same temperature, and further stirred at room temperature for 16 hours. After completion of the reaction, 800 ml of water was added to the flask and stirred vigorously, and then left to separate into an aqueous phase and an organic phase. This organic phase was further washed with 400 ml of water and dried over anhydrous magnesium sulfate overnight. Thereafter, magnesium sulfate was filtered off and the filtrate was concentrated. The crude product thus obtained was separated and purified by silica gel column chromatography (eluent: hexane / ethyl acetate), and the target colorless liquid, ie, 2- (3-oxetanyl) butyl tosylate was obtained. 243.3 g (yield 90%) was obtained.

  In a 200 ml three-necked flask equipped with a thermometer, a condenser and a stirrer, 1.03 g (3.5 mmol) of 1,3-bis (4-hydroxyphenoxy) benzene, 8 ml of N-methyl-2-pyrrolidone, And stirred until completely dissolved while heating to 80 ° C. in a nitrogen atmosphere. After dissolution, 2.74 g (8.41 mmol) of cesium carbonate was added, and the mixture was further stirred at 80 ° C. for 30 minutes in a nitrogen atmosphere. Thereto was added 2.08 g (7.69 mmol) of 2- (3-oxetanyl) butyl tosylate synthesized earlier, and the mixture was stirred at 80 ° C. for 20 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature (25 ° C.), and then 40 ml of ethyl acetate and 20 ml of distilled water were added to separate into an organic phase and an aqueous phase. The organic phase was further washed with water and saturated brine, and dried over anhydrous magnesium sulfate overnight. Then, after magnesium sulfate was filtered off, the solvent was distilled off to obtain a reaction crude product.

  The crude product thus obtained was analyzed by thin layer chromatography, and only one spot was confirmed. The crude product was purified by silica gel chromatography (eluent: n-hexane / acetone) to obtain 1.71 g (yield 99%) of a white solid. When the purity of the solid (compound) was examined by liquid chromatography, it was 99% or more.

The compound thus obtained is represented by the following structural formula (7) from the following results obtained by analysis using ¹ H-NMR and ¹³ C-NMR (both manufactured by JEOL Ltd.). 1,3-bis [4- [2- (3-oxetanyl)] butoxyphenoxy] benzene.

¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm); 0.89 (t, J = 7.6 Hz, 6H, CH ₃ ), 1.78 (q, J = 7.6 Hz, 4H, CH ₂ ), 4.07 (s, 4H, CH ₂ ), 4.33 (d, J = 5.6 Hz, 4H, CH ₂ ), 4.44 (d, J = 6.0 Hz, 4H, CH ₂ ), 6.47 (t, J = 2.4 Hz, 1H, Ar), 6.59 (dd, J = 2.4 Hz, J = 8.0 Hz, 2H, Ar), 7.02 (s, 8H, Ar) 7.27 (t, J = 8.0 Hz, 1H, Ar)
¹³ C-NMR (DMSO-d ₆ , 100 MHz): δ (ppm); 7.9, 26.18, 42.46, 70.58, 76.54, 76.60, 76.70, 106.27, 111.05, 115.84, 120.88, 130.72, 149.05, 155.34, 159.31

  An under cladding layer, a core portion, and an over cladding layer were formed as follows, and an optical waveguide was manufactured (see FIG. 1). And the evaluation with respect to the optical waveguide was performed as follows.

[Formation of underclad layer]
First, 70 parts by weight of 1,3-bis [4- [2- (3-oxetanyl)] butoxyphenoxy] benzene (hereinafter abbreviated as “parts”) obtained in Example 1 and alicyclic epoxy 3 , 4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexene carboxylate (Daicel Chemical Industries, Celoxide 2021P) and 4,4-bis [di (β-hydroxyethoxy) phenylsulfinio] 1 part of a 50% propion carbide solution of phenyl sulfide-bis-hexafluoroantimonate was dissolved in cyclohexanone to prepare a polymerizable composition A for forming a clad layer. Next, a glass substrate (5 cm × 5 cm × 2 mm in thickness) was prepared, and the polymerizable composition A was applied to the surface by a spin coating method and dried at 100 ° C. for 5 minutes. Then, the entire surface was irradiated with ultraviolet rays at a dose of 2000 mJ / cm ² , and subsequently heat-treated at 100 ° C. for 30 minutes to form an under cladding layer (see FIG. 2B). It was 30 micrometers when the thickness of this under clad layer was measured with the contact-type film thickness meter. The refractive index of the underclad was 1.535 at a wavelength of 633 nm.

[Formation of core part]
Next, 90 parts of 1,3-bis [4- [2- (3-oxetanyl)] butoxyphenoxy] benzene obtained in Example 1, 10 parts of bisphenoxyethanol fluorenediglycidyl ether (epoxy equivalent 320), 1,4-bis [di (β-hydroxyethoxy) phenylsulfinio] phenyl sulfide-bis-hexafluoroantimonate in 1 part of 50% propion carbide solution is dissolved in cyclohexanone to form a polymer for core formation. Composition B was prepared. And the said polymeric composition B was apply | coated on the said under clad layer by the spin coat method (refer FIG.2 (c)). The coated layer is dried at 150 ° C. for 20 minutes, and a synthetic quartz-based chromium mask (photomask) 9 on which a 50 μm-wide linear optical waveguide pattern is drawn is disposed thereon (FIG. 2 ( d)), an ultraviolet ray with an irradiation amount of 2000 mJ / cm ² was irradiated through the chrome mask 9 by a contact exposure method, and a heat treatment was performed at 150 ° C. for 30 minutes. Then, in order to remove an unirradiated part, development was performed using a γ-butyrolactone aqueous solution, and the core pattern was formed by further heating at 150 ° C. for 30 minutes (see FIG. 2E). When the core shape was measured with a side-length microscope, the core pattern had a square cross-sectional shape with a width of 50 μm and a height of 50 μm. Further, the refractive index of the core portion formed in this manner was 1.560 at a wavelength of 633 nm.

[Formation of overclad layer]
The same composition as the polymerizable composition A prepared at the time of forming the underclad layer was applied onto the core part and the underclad layer by a spin coating method. Next, it was dried at 100 ° C. for 5 minutes, irradiated with ultraviolet rays at an irradiation amount of 2000 mJ / cm ² , and subsequently heat-treated at 150 ° C. for 60 minutes to form an overcladding layer (FIG. 2 ( f)). In this way, an optical waveguide having a relative refractive index Δ = 1.6% was produced.

[Evaluation]
The optical waveguide was cut into a length of 10 cm using a dicing apparatus (Model 522 manufactured by Disco Corporation) and subjected to end face processing. When the cross-sectional shape of the optical waveguide was observed with a length measuring microscope, it was found to be a buried multimode optical waveguide with an under cladding layer thickness of 30 μm, a core portion of 50 μm × 50 μm, and an over cladding layer thickness of 70 μm. It was confirmed. And when this optical waveguide was measured for light propagation loss by a conventional cutback method using laser light having a wavelength of 850 nm, it was 0.09 dB / cm. Moreover, this waveguide can be made into a film-like waveguide by peeling from the substrate. And this film-form waveguide was good also in flexibility, such as a loss fall not being observed with respect to the bending of R = 20mm, and the bending of R = 5mm being possible.

  The bisoxetane compound of the present invention is used as a constituent of a photocurable resin composition or a thermosetting resin composition, and these resin compositions include, for example, paints, coating materials, adhesives, optical lenses, optical waveguides, and the like. Used in various forming materials. Examples of the optical waveguide include a straight optical waveguide, a curved optical waveguide, a crossed optical waveguide, a Y-branch optical waveguide, a slab optical waveguide, a Mach-Zehnder optical waveguide, an AWG optical waveguide, a grating, and an optical waveguide lens. It is done. The optical device using the optical waveguide includes a wavelength filter, an optical switch, an optical splitter, an optical multiplexer, an optical multiplexer / demultiplexer, an optical amplifier, a wavelength converter, a wavelength divider, an optical splitter, and directional coupling. And an optical transmission module in which a laser diode and a photodiode are hybrid-integrated.

It is a cross-sectional view showing an example of the optical waveguide of the present invention. (A)-(e) is explanatory drawing which shows the manufacturing process of the optical waveguide of this invention.

Explanation of symbols

1 Substrate 2 Clad layer 3 Core part

Claims (5)

A bisoxetane compound represented by the following general formula (1).

It is a manufacturing method of the bisoxetane compound of Claim 1, Comprising: The phenols represented by following General formula (2) are cesium phenolate by a cesium salt, Then, it represents with following General formula (3) A process for producing a bisoxetane compound, characterized by reacting with a sulfonic acid ester of 3-alkyl-3-hydroxymethyloxetane.

  The process for producing a bisoxetane compound according to claim 2, wherein the cesium salt is cesium carbonate.   An optical waveguide comprising a substrate and a clad layer formed on the substrate, wherein a core portion that propagates an optical signal in a predetermined pattern is formed in the clad layer, wherein the clad layer and the core portion At least one is formed with the resin composition containing the bisoxetane compound of Claim 1, The optical waveguide characterized by the above-mentioned.   The optical waveguide according to claim 4, wherein at least one of the cladding layer and the core part is formed of a resin composition containing the bisoxetane compound according to claim 1 and a compound having an epoxy group or a vinyl ether group.

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