JP2003213243A - Adhesive composition for optical use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an adhesive composition for optical use, manifesting high activities (rapid polymerization, rapid curing) by irradiation with active energy rays and/or heating, and capable of freely adjusting the refractive index. <P>SOLUTION: This adhesive composition for optical use contains (a) an alicyclic compound having at least one oxetanyl group in the molecule and (b) a compound capable of initiating a cationic polymerization by irradiation with active energy rays and/or heating. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical adhesive composition which can be mounted on an optical member and an optical member using the adhesive composition.

[0002]

2. Description of the Related Art IC (Integrated circuit)
Due to technological advances in LSIs and large scale integrated circuits (LSIs), their operating speeds and integration scales have been improved, and high performance of microprocessors and large capacity of memory chips have been rapidly achieved. Conventionally, information transmission over a relatively short distance such as between boards in a device or between chips in a board has been mainly performed by electric signals. In the future, in order to further improve the performance of integrated circuits, it is necessary to further speed up signals and increase the density of signal wiring, but in electric signal wiring, these speeding up and high density are reaching their limits. CR of wiring
(C: capacitance of wiring, R: resistance of wiring) Signal delay due to time constant is a problem. In addition, EMI (Electromagneti)
c Interference) It causes noise, and its countermeasures are also indispensable.

Therefore, as a solution to these problems, attention has been paid to optical wiring (optical interconnection). The optical wiring is considered to be applicable to various locations such as between devices, between boards within a device, or between chips within a board. In particular, for signal transmission over a short distance such as between chips, it is preferable to form an optical waveguide on a substrate on which the chip is mounted and construct an optical transmission / communication system using this as a transmission path. It is believed that there is.

Further, recently, an inorganic glass such as quartz has been used as an optical communication material of this kind. However, when forming an optical waveguide using inorganic glass, it is necessary to perform heat treatment at high temperature, so the optical waveguide is formed on a substrate such as a semiconductor substrate or a plastic substrate that is difficult to perform heat treatment at high temperature. It could not be formed. Furthermore, it is not easy to obtain the matching of the refractive indexes. On the other hand, in recent years, an optical waveguide using a polymer material has been proposed and put into practical use. A polymer material is easier to process than an inorganic material, and can be easily formed into a large area or formed into a film. In addition, since it is flexible, it has various advantages such as wide application and easy adjustment of the refractive index. In such an optical material, there is a demand for an optical adhesive capable of controlling a refractive index in bonding or fixing each of inorganic and organic materials and fixing them, and having excellent adhesive strength after wet heat treatment. . The required characteristic of the optical adhesive is a return loss (RL) of 35 dB.
The refractive index matching properties that can be achieved as described above, the fluidity that makes it possible to easily fill a capillary of about 100 μm, and the curability for a short time (several minutes) from the viewpoint of ensuring workability, etc. Among them, the ultraviolet curable resin is a material that can be cured for a short time and can be mass-produced for optical communication circuits.
It is expected as a material for optical adhesives. An epoxy resin is widely known as such an ultraviolet curable resin. For example, the optical waveguide using epoxy resin is
Generally, it is formed by applying a resin on a supporting substrate, selectively exposing the resin, and then performing a developing treatment of wet etching the uncured portion of the resin. However, since the epoxy resin has a low polymerizability, a large amount of energy is required for curing the resin when bonding is performed using the epoxy resin, which causes a problem that the production efficiency is deteriorated. An optical connector used for connecting optical fibers to each other has a ferrule for fixing the tip end portion of the optical fibers. Usually for ferrules
It is a ceramic material such as zirconia, and has an optical fiber insertion hole for inserting an optical fiber and fixing it with an adhesive. Epoxy resin is generally used as the adhesive because it can be cured in a short time, but there is a problem that the fixing strength cannot be sufficiently secured because the fiber insertion hole has an extremely short length of 3 mm. On the other hand, it is known that when an oxetane compound is mixed with an epoxy compound, cationic curing is significantly improved. Because of this,
In 000-356720, an optical waveguide using these oxetane compounds is shown, but at present it cannot be said that it has a sufficient curing rate for actually being used as an optical communication material.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an optical adhesive composition having excellent polymerizability and having sufficient fixing strength, and an optical communication material using the same. An object is to provide an optical connector and a manufacturing method thereof.

[0006]

Means for Solving the Problems As a result of intensive studies on the solution of the above-mentioned problems, the present inventors have identified a specific cationically polymerizable compound and a compound that initiates cationic polymerization by irradiation with active energy rays and / or heating. It was found that a composition for optical adhesives containing can solve the above problems,
The present invention has been completed.

That is, the present invention provides the following [1]-[1]
[9] The composition for optical adhesives, the optical communication material using the same, and the method for producing the same.

[1] A composition for an optical adhesive, which contains an alicyclic compound (a) having at least one oxetanyl group in the molecule.

[2] The optical adhesive according to [1], wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (1). Composition.

[Chemical 4] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, and the others are 1.) [3] The compound represented by the general formula (1) is 2-oxaspiro [3.5] non-6-ene or 5-methyl-2-.
The composition for optical adhesives according to [2], which is oxaspiro [3.5] non-6-ene.

[4] The optical adhesive according to [1], wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (2). Composition.

[Chemical 5] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, and the others are 1.) [5] The compound represented by the general formula (2) is 2-oxaspiro [3.5] nonane or 5-methyl-2-oxaspiro [3.5] nonane. [4] The composition for optical adhesives according to [4].

[6] The optical adhesive according to [1], wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (3). Composition.

[Chemical 6] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, otherwise is 1.)

[7] The compound represented by the general formula (3) is 7,8-epoxy-5-methyl-2-oxaspiro [3.5] nonane, 6,7-epoxy-2-oxaspiro [3.5]. It is nonane, The composition for optical adhesives as described in [6]. [8] The alicyclic compound (a) having at least one oxetanyl group in the molecule is represented by the general formula (1) or the general formula (2).
And at least one selected from the compounds represented by the general formula (3), the composition for optical adhesives according to [1]. [9] The composition for optical adhesive according to any one of [1] to [8], which contains the compound (b) having one or more epoxy groups and not having an oxetanyl group. .

[10] having one or more epoxy groups,
The composition for optical adhesive according to [9], wherein the compound (b) having no oxetanyl group has a fluorine atom. [11] The composition for optical adhesives according to any one of [1] to [10], which comprises a compound (c) that initiates cationic polymerization by irradiation with active energy rays and / or heating. . [12] The compound (c) which initiates cationic polymerization upon irradiation with active energy rays and / or heating is one or more selected from sulfonium salts, iodonium salts, phosphonium salts and diazonium salts. The composition for optical adhesives of.

[13] The composition for optical adhesive according to any one of [1] to [12], which contains a radically polymerizable compound (d). [14] The composition for optical adhesive according to any one of [1] to [13], which comprises a photoradical initiator (e). [15] The refractive index of the cured product against sodium D line at 25 ° C. is a value within the range of 1.40 or more and 1.70 or less. 15. The composition for optical adhesives of.

[16] An optical communication circuit formed by using the composition for optical adhesive according to any one of [1] to [15]. [17] An optical communication material, which is formed by using the composition for optical adhesive according to any one of [1] to [15]. [18] An optical connector using the composition for optical adhesive according to any one of [1] to [15].

[19] Composition for optical adhesive containing alicyclic compound (a) having at least one oxetanyl group in the molecule and compound (c) which initiates cationic polymerization upon irradiation with active energy rays and / or heating A method for producing an optical communication material, which comprises selectively irradiating an object with an active energy ray to selectively cure the composition, and then performing a development treatment for removing an uncured portion.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The alicyclic compound (a) having at least one oxetanyl group in the same molecule of the present invention (hereinafter abbreviated as compound (a)) is represented by the general formula (1), the general formula (2) or the general formula (2). The alicyclic compound represented by the formula (3) is preferable. In the general formulas (1), (2), and (3), each R is independently a hydrogen atom, a linear or branched alkyl group, aryl group, aralkyl group, or halogen having 1 to 12 carbon atoms. Each group of the alkylated alkyl group. Among these, a hydrogen atom and a linear alkyl group are preferable, and a hydrogen atom and a methyl group are particularly preferable. m is an integer from 0 to 2, and n
Is 2 when m is 0, and is 1 otherwise. m = 0 means that there is no crosslinking by methylene chains.

A straight or branched chain having 1 to 12 carbon atoms,
Examples of the alkyl group, aryl group and aralkyl group include a methyl group, an ethyl group, an isopropyl group, a phenyl group and a benzyl group.

Examples of the halogenated alkyl group include a fluoroalkyl group, a chloroalkyl group and a bromoalkyl group. Each of these alkyl groups may be linear or branched, and the number of each halogen atom may be 1 or more.

As the compound represented by the general formula (1),
2-Oxaspiro [3.5] non-6-ene, 9-methyl-2-oxaspiro [3.5] non-6-ene, 2-
Oxa-9-phenylspiro [3.5] non-6-ene, 9-trifluoromethyl-2-oxaspiro [3.
5] Nona-6-ene, spiro [bicyclo [2.2.1]]
Hepta-5-ene-2,3'-oxetane], spiro [3-methylbicyclo [2.2.1] hept-5-ene-2,3'-oxetane] and the like can be mentioned. Among these, 2-oxaspiro [3.5] non-6-ene, 9-
Methyl-2-oxaspiro [3.5] non-6-ene is preferred.

These compounds have an oxetanyl group and a carbon-carbon double bond, and are not only cationically polymerizable but also
It also has excellent radical polymerizability and contributes to the improvement of the curing speed. Further, since it has an alicyclic structure, the cured product of the composition of the present invention has excellent heat resistance. Furthermore, since most of the compounds represented by the general formula (1) are liquids at room temperature, it becomes possible to adjust the viscosity of the composition of the present invention and improve workability.

As the compound represented by the general formula (2),
2-oxaspiro [3.5] nonane, 7-methyl-2-
Oxaspiro [3.5] nonane, 5-methyl-2-oxaspiro [3.5] nonane, 2-oxa-5-phenylspiro [3.5] nonane, 5-trifluoromethyl-2
-Oxaspiro [3.5] nonane, spiro [adamantan-2,3'-oxetane], spiro [bicyclo [2.
2.1] heptane-2,3′-oxetane], spiro [bicyclo [2.2.2] octane-2,3′-oxetane], spiro [7-oxabicyclo [2.2.1] heptane-2. , 3′-oxetane], spiro [3-methylbicyclo [2.2.1] heptane-2,3′-oxetane] and the like. Among these, 2-oxaspiro [3.5] nonane and 5-methyl-2-oxaspiro [3.5] nonane are preferable.

These compounds have excellent cationic polymerizability and have the effect of improving the curing rate of the composition. Further, the alicyclic structure imparts heat resistance to the cured product of the composition of the present invention. Furthermore, since most of the compounds represented by the general formula (2) are liquid at room temperature, it is possible to adjust the viscosity of the composition of the present invention and improve workability.

As the compound represented by the general formula (3),
7,8-Epoxy-5-methyl-oxaspiro [3.
5] nonane, 7,8-epoxy-5-ethyl-2-oxaspiro [3.5] nonane, 7,8-epoxy-2-oxa-5-phenylspiro [3.5] nonane, 7,8-
Epoxy-5-trifluoromethyl-2-oxaspiro [3.5] nonane, 6,7-epoxy-2-oxaspiro [3.5] nonane, spiro [5,6-epoxynorbornane-2,3'-oxetane ], Spiro [5,6-epoxy-3-methylnorbornane-2,3′-oxetane] and the like. Among these, 7,8-epoxy-5
Methyl-2-oxaspiro [3.5] nonane, 6,7-
Epoxy-2-oxaspiro [3.5] nonane is preferred.

Since these compounds have both an oxetanyl group and an epoxy group, they have excellent cationic polymerizability and contribute to the improvement of the curing rate of the composition. In addition, it has an alicyclic structure and enhances the heat resistance of the cured product.

The compound (a) including alicyclic compounds having one or more oxetanyl groups in the molecule represented by the general formulas (1), (2) and (3) may be used alone or in combination of two kinds. It can be used as a mixture of the above. The compounding amount of these compounds (a) (when two or more kinds are used in combination, the total amount thereof) is preferably 1 to 90% by mass, more preferably 10 to 60% by mass in the composition for optical adhesives of the present invention. Is.

As the compound (b) having one or more epoxy groups in the molecule of the present invention and not having an oxetanyl group, known and commonly used epoxy compounds can be used. This epoxy compound is not particularly limited as long as it has one or more epoxy groups in one molecule and does not have an oxetanyl group.

Specifically, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether,
Bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, novolac type epoxy resin (for example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Brominated phenol / novolak type epoxy resin), hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether,
Triglycidyl isocyanurate or the like can be used.

As the aliphatic epoxy compound,
(3,4-epoxycyclohexyl) methyl-3 ′,
4'-epoxy cyclohexyl carboxylate, 2-
(3,4-epoxycyclohexyl-5,5-spiro-
3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-)
6-methylcyclohexylmethyl) adipate, 3,4
-Epoxy-6-methylcyclohexyl-3 ', 4'-
Epoxy-6'-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, limonene diepoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,3) 4-epoxycyclohexanecarboxylate)
Is mentioned.

Further, epoxy dioctyl hexahydrophthalate, di-2-ethylhexyl epoxy hexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether,
1 for aliphatic polyhydric alcohols such as glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, ethylene glycol, propylene glycol and glycerin
Or polyglycidyl ethers of polyether polyols obtained by adding two or more alkylene oxides; diglycidyl ethers of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; butylglycidyl ether, Phenyl glycidyl ether, cresol glycidyl ether, nonyl phenyl glycidyl ether, glycidyl methacrylate;
Phenol, cresol, butylphenol or monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these; glycidyl esters of higher fatty acids; epoxidized soybean oil; butyl epoxystearate, octyl epoxystearate, epoxidized linseed Examples thereof include oil and epoxidized polybutadiene.

Further, a fluorinated epoxy compound having a fluorine atom can be used to adjust the refractive index of the optical adhesive or the optical communication material of the present invention. A fluorinated epoxy compound has a smaller refractive index than a hydrocarbon type epoxy compound having a similar structure, and can be adjusted to a desired refractive index by mixing with a composition for optical adhesives. .

Specifically, "Applied Physics Vol. 68, No. 1 (1
999), p. 4 to 13 ", examples of the following compounds are described, but the present invention is not limited thereto.

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10]

[Chemical 11]

The compound (b) having one or more epoxy groups in the molecule and not having an oxetanyl group can be used alone or in combination of two or more kinds.

The compounding amount of the compound (b) (when two or more kinds are used in combination, the total amount thereof) is 1 to 10,000 per 100 parts by mass of the total amount of the compound (a) in the present invention.
A mass part is preferable and a 10-1,000 mass part is especially preferable.

The compound (c) used in the present invention to initiate cationic polymerization by irradiation with active energy rays and / or heating is changed by heating or irradiation with active energy rays such as ultraviolet rays to initiate cationic polymerization of acids. It can be a compound that produces a substance. Therefore, the compound (c) is a kind of cationic polymerization initiator and is also referred to as "acid generator" in the art. Hereinafter, in the present invention, the compound (c) is also referred to as an acid-generating cationic polymerization initiator.

The acid-generating type cationic polymerization initiator is a compound (a) of the present invention when heated or irradiated with light such as ultraviolet rays.
It promotes the cationic polymerization of the compound (b) and other cationically polymerizable substances (compounds containing an oxetanyl group, etc.) so that the curing of the optical adhesive composition of the present invention proceeds smoothly.

The acid-generating type cationic polymerization initiator referred to in the present invention is a compound which is changed by heating or irradiation with active energy rays such as ultraviolet rays to produce a substance such as acid which initiates cationic polymerization. Thus, compounds that are in the acid form from the beginning are not included.

As the acid-generating type cationic polymerization initiator, known sulfonium salts, iodonium salts, phosphonium salts,
Examples thereof include diazonium salts, ammonium salts and ferrocenes. Specific examples are shown below, but the present invention is not limited to these compounds.

Examples of the sulfonium salt-based acid-generating type cationic polymerization initiator include bis [4- (diphenylsulfonio)]
Phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate, bis [4- (diphenylsulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- (diphenylsulfone) Nio) phenyl] sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (phenylthio) phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetra Fluoroborate, diphenyl-4- (phenylthio) phenylsulfonium tetrakis (pentafluorophenyl) borate, tri Phenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfo Nio) phenyl] sulfide bishexafluorophosphate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluoroantimonate, bis [4
-(Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide tetrakis ( Pentafluorophenyl) borate, and the like.

As the iodonium salt-based acid-generating type cationic polymerization initiator, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) ) Iodonium hexafluorophosphate, bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1) −
Methylethyl) phenyliodonium hexafluorophosphate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4
-Methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl)
Examples include borate.

As the phosphonium salt-based acid-generating cationic polymerization initiator, ethyltriphenylphosphonium tetrafluoroborate, ethyltriphenylphosphonium hexafluorophosphate, ethyltriphenylphosphonium hexafluoroantimonate, tetrabutylphosphonium tetrafluoroborate, tetra Examples thereof include butylphosphonium hexafluorophosphate and tetrabutylphosphonium hexafluoroantimonate.

Examples of the diazonium salt-based acid-generating cationic polymerization initiator include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate. .

Examples of ammonium salt-based acid-generating cationic polymerization initiators include 1-benzyl-2-cyanopyridinium hexafluorophosphate and 1-benzyl-2-
Cyanopyridinium hexafluoroantimonate,
1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1-
(Naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-
Cyanopyridinium hexafluoroantimonate,
1- (naphthylmethyl) -2-cyanopyridinium tetrafluoroborate, 1- (naphthylmethyl) -2-
Examples include cyanopyridinium tetrakis (pentafluorophenyl) borate, and the like.

As the ferrocene-based acid-generating type cationic polymerization initiator, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe (II) hexafluorophosphate, (2,4 -Cyclopentadiene-1-yl) [(1-methylethyl) benzene]-
Fe (II) hexafluoroantimonate, 2,4-cyclopentadiene-1-yl) [(1-methylethyl)
Benzene] -Fe (II) tetrafluoroborate, 2,
4-cyclopentadiene-1-yl) [(1-methylethyl) benzene] -Fe (II) tetrakis (pentafluorophenyl) borate, and the like.

Of these acid-generating type cationic polymerization initiators, sulfonium salt and iodonium salt type initiators are preferable from the viewpoint of curing rate, stability and economy. As commercial products, SP-150, SP-170, CP manufactured by Asahi Denka Co., Ltd.
-66, CP-77; CYRA manufactured by Union Carbide
CURE-UVI-6990, UVI-6974; Nippon Soda Co., Ltd. CI-2855, CI-2638; Sanshin Chemical Industry Co., Ltd., San-Aid SI-60; "Irgacure 261".
(Ciba Specialty Chemicals (2,4-cyclopentadien-1-yl) [(1-methylethyl)
Benzene] -Fe (II) hexafluorophosphate), “RHODORSIL 207
4 "; (4-methylphenyl-4 manufactured by Rhone-Poulin)
-(1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate), and the like.

These acid-generating type cationic polymerization initiators may be selected from the above-mentioned materials and used alone or in combination of two or more kinds.
The preferred range of the amount of the acid-generating cationic polymerization initiator used is
There is no particular limitation, but the total compounding amount of the compound (a) and the compound (b) (when the other cationically polymerizable compound described later is used together, the total amount thereof) is 100 parts by mass. 05 to 25 parts by mass, preferably 1 to 20 parts by mass. If the amount added is less than 0.05 parts by mass, the sensitivity will be poor, and remarkably large light irradiation energy and high temperature treatment for a long time are required for sufficient curing. Further, even if added in excess of 25 parts by mass, the sensitivity is not improved, which is economically unfavorable. On the contrary, the amount of uncured components remaining in the adhesive may increase, and the physical properties of the cured product may deteriorate.

In the present invention, the following cationically polymerizable monomers can also be added to the composition for optical adhesives of the present invention within a range that does not affect the curability and the physical properties of the cured product. This cationically polymerizable monomer is a compound that causes a polymerization initiation reaction or a crosslinking reaction by the acid generated by the acid-generating cationic polymerization initiator and is classified into compounds other than the compound (a) and the compound (b). For example, trimethylene oxide, 3,3-dimethyloxetane, 3,3-dichloromethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane (manufactured by Toagosei Co., Ltd .; trade name EOXA) , Bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene (also known as xylylenedioxetane; manufactured by Toagosei Co., Ltd .; trade name XDO), tri [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, bis [ (3-Ethyl-3-oxetanylmethoxy) methylphenyl] ether, 3-
Oxetane compounds having an oxetanyl group in addition to alicyclic compounds such as ethyl-3-[(oxiranylmethoxy) methyl] oxetane and (3-ethyl-3-oxetanylmethoxy) oligodimethylsiloxane; tetrahydrofuran, 2,3 An oxolane compound such as dimethyltetrahydrofuran; trioxane, 1,3-dioxolane,
Cyclic acetal compounds such as 1,3,6-trioxanecyclooctane; cyclic lactone compounds such as β-propiolactone and ε-caprolactone; ethylene sulfide
Thiirane compounds such as 1,2-propylene sulfide and thioepichlorohydrin; Thiethane compounds such as 3,3-dimethylthietane; Vinyl ether compounds such as ethylene glycol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether; Examples thereof include spiro orthoester compounds which are reaction products of epoxy compounds and lactones; ethylenically unsaturated compounds such as vinylcyclohexane, isobutylene and polybutadiene; cyclic ether compounds; cyclic thioether compounds; vinyl compounds and the like.

These cationically polymerizable monomers may be added alone or in combination of two or more. The amount of these cationically polymerizable monomers (when two or more kinds are used in combination, the total amount thereof) is 1 to 10,000 parts by mass, preferably 10 parts by mass, relative to 100 parts by mass of the compound (a) of the present invention. ~
1,000 parts by mass. Of the above-mentioned cationically polymerizable monomers, the compound having only one cationically polymerizable group in the molecule is 20 per 100 parts by mass of the compound (a).
If it is added in an amount of 0 part by mass or more, the curability is lowered and the energy required for curing is increased, which is not preferable.

It is also possible to add a radically polymerizable compound (d) to the composition for optical adhesives of the present invention in order to improve the photocurability (active energy ray), so long as the object of the present invention is not impaired. Is. The compound (d) is not particularly limited, but (meth) acrylic acid ester-based known and commonly used radically polymerizable monomers can be used. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth ) Acrylate, phenoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, benzyl (meth) acrylate, ethylene glycol mono (meth) acrylate, etc. Functional (meth) acrylate compound; ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra ( Data) acrylate, dipentaerythritol penta (meth) acrylate, multifunctional epoxy (meth) acrylate resin, a polyfunctional urethane (meth) acrylate resin.

Further, a (meth) acrylate monomer having a fluorine atom may be used as the compound (d) for the purpose of adjusting the refractive index of the optical adhesive or the optical communication material of the present invention. Specifically, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, pentafluoropropyl (meth) acrylate, hexafluoroisopropyl (meth) acrylate, Octafluoropentyl (meth) acrylate and the like can be mentioned.

The amount of the compound (d) added is 5 to 100 parts by mass of the total amount of the compound (a), the compound (b), the compound (c) of the present invention and the above-mentioned other cationically polymerizable compounds. 200 parts by mass, preferably 10 to 100 parts by mass. If the amount added exceeds 200 parts by mass, the dryness to the touch will deteriorate. In addition, since the ratio of cross-linking of the (meth) acrylic group increases during curing, the heat resistance of the obtained cured product
Chemical resistance decreases.

In order to smoothly promote the radical polymerization of the above radically polymerizable compound (d), it is desirable to add a photoradical initiator (e), and a known conventional one which is sensitive to light and generates a radical can be used. . Here, “light” means visible rays, ultraviolet rays, far ultraviolet rays, X-rays, electron rays, and other radiation. Examples of the photo radical initiator (e) include benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, 2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-
Methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-
[4- (methylthio) phenyl] -2-morpholinopropan-1-one (manufactured by Ciba Specialty Chemicals; Irgacure 907), 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, Benzophenone, p-phenylbenzophenone,
4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-
Methylthioxanthone, 2-ethylthioxanthone, 2
-Chlorothioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, p-dimethylamine benzoate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF; Lucillin TPO), bis (2,6- Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide-containing initiator (manufactured by Ciba Specialty Chemicals; Irgacure 1700,149,1800),
Examples thereof include bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba Specialty Chemicals; Irgacure 819). These can be used alone or as a mixture of two or more.

The amount of the photoradical initiator (e) used is 0.007 with respect to 1 equivalent of the radical-polymerizable functional group such as the (meth) acryl group of the radical-polymerizable compound (d) in the composition.
~ 0.5 mol can be used.

If desired, the composition for optical adhesives of the present invention may contain an ion trap agent. The ion trap agent reacts with impurities such as anions and cations, and can be converted into a substance that makes it harmless.

The optical adhesive composition of the present invention may further contain an aliphatic polyol. Such an aliphatic polyol imparts flexibility to the optical adhesive composition of the present invention and enhances the completion of the reaction at room temperature aging after the curing reaction. Examples of the aliphatic polyol include (poly) alkylene glycols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol and butylene glycol, as well as glycerin, polyglycerin, pentaerythritol and polycaprolactone polyol. The blending amount is 5 to 50 parts by mass, preferably 10 to 30 parts by mass per 100 parts by mass of the components (a) to (e) and the other cationically polymerizable monomer components in the composition for an optical adhesive of the present invention. It may be about parts by mass.

When the composition for optical adhesives of the present invention is polymerized and cured by ultraviolet rays, which is one of the active energy rays, a sensitizer may be used in order to improve the polymerization rate. As the sensitizer used for such a purpose, pyrene, perylene, 2,4-diethylthioxanthone, 2,
4-dimethylthioxanthone, 2,4-dichlorothioxanthone, phenothiazine and the like can be mentioned. When the sensitizer is used in combination, the amount used is preferably in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the photoacid-generating cationic polymerization initiator.

Further, if necessary, an antifoaming agent such as a silicone type, a fluorine type or a polymer type; a leveling agent; an adhesion imparting agent such as an imidazole type, a thiazole type, a triazole type or a silane coupling agent, for example, Shin-Etsu Silicone. Silane coupling agent, KBM303, KBM403,
KBM402; Use of well-known and commonly used additives such as flame retardants such as antimony trioxide, phosphoric acid ester, red phosphorus, and nitrogen-containing compounds such as melamine resin, and stress relaxation agents such as silicone oil and silicone rubber powder. You can

The composition for optical adhesives of the present invention contains constituents such as the compound (a), the compound (b) and the compound (c) described above, which are agitated by a blade, an agitator-kneader, a paint shaker and a kneader. , A three-roll mill or the like can be used for mixing. The mixing device is not particularly limited as long as it is a device capable of uniformly mixing the constituent substances, but it is necessary to select it in consideration of the viscosity of the composition and the like.

The composition for optical adhesives of the present invention can be polymerized (cured) by irradiation with active energy rays and / or heating. The active energy ray here means ultraviolet rays, X-rays, electron rays, γ rays and the like. Examples of the light source for irradiation with ultraviolet rays include metal halide lamps, mercury arc lamps, xenon arc lamps, fluorescent lamps, carbon arc lamps, tungsten-halogen copying lamps, and sunlight.

When the optical adhesive composition of the present invention is cured by heating, the heating conditions are preferably about 50 to 25.
0.degree. C., more preferably at about 75-200.degree.
The conditions may be 2 to 60 minutes, preferably about 0.5 to 20 minutes, more preferably about 1 to 10 minutes.

The refractive index of the optical communication material of the present invention is preferably 1.40 to 1.70 with respect to the D line of sodium at 25 ° C. Therefore, the refractive index of the composition for optical adhesive is also 1. It is preferably 40 to 1.70.

Generally, the composition for an optical adhesive is a mixture of an oxetane compound, an epoxy compound and the like as described above. These oxetane compounds and epoxy compounds have a refractive index of about 1.40 to 1.70, and it is possible to arbitrarily control the refractive index of the optical waveguide resin by appropriately selecting these compounds or changing the compounding ratio. Is possible.

The curing treatment of the optical adhesive of the present invention may be performed by light irradiation and heat treatment as in the conventional case, but in the heat curing particularly when an epoxy adhesive is used, it is sufficiently cured from a relatively low temperature condition. If the heating is performed in a few steps up to the temperature at which the curing proceeds, and then the curing is completed at a lower temperature, a more excellent solid strength can be obtained.

[0065]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, "part" in Examples and Comparative Examples
Is parts by mass unless otherwise specified.

Among the materials used in Examples and Comparative Examples, commercially available products are as follows, and without purification,
Used as is. POX: Toagosei Co., Ltd., 3-ethyl-3-phenoxymethyloxetane XDO: Toagosei Co., Ltd., 1,4-bis [(3-ethyl-
3-oxetanylmethoxy) methyl] benzene 3000: manufactured by Daicel Chemical Industries, Ltd. (trade name Celoxide 3000), limonendioxide 2110: manufactured by Asahi Denka Industry (trade name KRM-2110),
Bifunctional alicyclic epoxy resin 828: manufactured by Yuka Shell Epoxy Co., Ltd.
28), bisphenol A type epoxy resin M-309: Toagosei Co., Ltd., trimethylolpropane triacrylate 3000A: Kyoeisha Chemical Co., Ltd. epoxy ester 3000.
A, bisphenol A diglycidyl ether acrylic acid adduct SI-60L: Sanshin Chemical Industry Co., Ltd.
I-60L), thermal cationic polymerization initiator (sulfonium salt) 6990: manufactured by Union Carbide (trade name UVI-6).
990), a cationic photopolymerization initiator 907: manufactured by Ciba Specialty Chemicals (trade name Irgacure 907), a photopolymerization initiator

As the compound not commercially available, the one chemically synthesized by the inventor was used. That is, 7,8-epoxy-5
Methyl-2-oxaspiro [3.5] nonane and 6,
The 7-epoxy-2-oxaspiro [3.5] nonane was synthesized by the present inventor with reference to the method described in US Pat. No. 3,388,105. Specifically, 7,8-epoxy-5-
Methyl-2-oxaspiro [3.5] nonane was synthesized as follows.

<6-methyl-3-cyclohexene-1,
Synthesis of 1-dimethanol> In a three-necked flask, 327 g of 2-methyl-4-cyclohexene-1-carbaldehyde, which is a Diels-Alder reaction product of butadiene and crotonaldehyde, 600 ml of methanol and 729 g of 37% formalin water. Charge and stir this solution 6
The temperature was raised to 0 ° C. Then, 252 g of KOH was added to 60 parts of distilled water.
The solution dissolved in 0 ml was added dropwise over 2 hours. After continuing stirring for 7 hours, the reaction solution was concentrated under reduced pressure to obtain a bilayer residue. The oil layer concentrated to about 150 ml was washed with 300 ml of distilled water. After the oil layer was concentrated under reduced pressure, 50 mg of 3,5-di (t-butyl) -4-hydroxytoluene (BHT) was added and distilled under reduced pressure to give 6-colorless crystals.
Methyl-3-cyclohexene-1,1-dimethanol 3
11 g (yield 82%) was obtained.

<6-methyl-3-cyclohexene-1,
Synthesis of 1-dimethanol cyclic carbonic acid ester> A 3-necked flask was charged with 310 g (1.99 mol) of 6-methyl-3-cyclohexene-1,1-dimethanol, 894 g of dimethyl carbonate (DMC) and 0.93 g of potassium carbonate, The temperature was raised to 90 ° C. and the mixture was refluxed for 4 hours. The reaction solution was returned to room temperature and potassium carbonate was filtered off. BHT 120mg
After adding, the remaining DMC and methanol are adjusted to 2 kPa.
(15 mmHg) was removed under reduced pressure, followed by vacuum distillation to obtain 326 g of 6-methyl-3-cyclohexene-1,1-dimethanol cyclic carbonic acid ester, which is a room temperature colorless crystal.
(Yield 89.4%) was obtained.

<9-Methyl-2-oxaspiro [3.5]
Synthesis of nona-6-ene (CHEO)> In a three-neck flask, 6-methyl-3-cyclohexene-1,1-dimethanol cyclic carbonic acid ester 321.15 g, BHT642 mg
(0.2 mass%) and LiCl (1.93 g) were charged, and the mixture was heated and stirred at 275 ° C. using a mantle heater. The product was immediately discharged under reduced pressure of about 8 kPa (60 mmHg) to the outside of the system, and heating was continued for 4 hours until distilling stopped. BHT (600 mg) was added to the product, and vacuum distillation was performed to obtain 187 g (yield 71%) of CHEO as a colorless transparent liquid.

<Synthesis of 7,8-epoxy-5-methyl-2-oxaspiro [3.5] nonane (ECHO)> CH
50 g of EO was dissolved in 150 ml of dichloromethane and then charged into the reactor. m-chloroperbenzoic acid 93.7
What was suspended in 400 ml of dichloromethane was added dropwise over 1 hour so that the reaction solution did not exceed 40 ° C. The precipitated m-chlorobenzoic acid was filtered off and washed well with cold dichloromethane. Calcium hydroxide 1 in the organic layer
After adding 5.0 g and stirring for 30 minutes, the precipitated crystals were separated by filtration and washed with cold dichloromethane. The organic layer is 5% Na
After washing with HSO4 water and saturated saline solution and concentrating, 38.1 g of colorless semi-solid ECHO at room temperature by vacuum distillation.
(Yield 73.7%) was obtained.

<Synthesis of 7,8-epoxy-5-ethyl-2-oxaspiro [3.5] nonane (EECHO)> E
Instead of the Diels-Alder reaction product of butadiene and crotonaldehyde used in the synthesis of CHO, a Diels-Alder reaction product of butadiene and trans-2-pentenal, 6-ethyl-3-cyclohexene-1-carbo Synthesized by the present inventor using an aldehyde by a procedure similar to the above.

<7,8-Epoxy-5-trifluoromethyl-2-oxaspiro [3.5] nonane (EFCH
O) Synthesis> Instead of the Diels-Alder reaction product of butadiene and crotonaldehyde used in the synthesis of ECHO, Diels-Alder reaction product of butadiene and trans-4,4,4-trifluoro-2-butenal Was synthesized by the present inventor by a procedure similar to the above.

<5-methyl-2-oxaspiro [3.
5] Synthesis of nonane (CHO)> Obtained by hydrogenating the above-mentioned 6-methyl-3-cyclohexene-1,1-dimethanol in 1L three-necked flask in toluene with hydrogen gas using 5% palladium / activated carbon as a catalyst. 2-methylcyclohexane-1,1-dimethanol (474 g), dimethyl carbonate (405 g) and potassium carbonate (1.4 g) were added, and the mixture was heated with stirring at a temperature of 100 ° C. in an oil bath, and the produced methanol was distilled out of the system under normal pressure. The reaction was carried out for 14 hours. Finally, the pressure inside the reaction vessel was reduced to 10 mmHg to obtain the corresponding carbonate ester in a yield of 95%.

The cyclic ester carbonate thus obtained was used as it was for 25
The mixture was heated and stirred at 0 ° C., and the generated carbon dioxide gas was discharged from the upper part of the cooling device to the outside of the system to carry out the reaction for 10 hours. The reaction solution was purified by distillation to obtain 230 g of CHO.

<2-oxa-5-phenylspiro [3.
5] Synthesis of Nonane (PCHO)> Instead of 2-methylcyclohexane-1,1-dimethanol used in the synthesis of CHO, a Diels-Alder reaction product of butadiene and trans-cinnamic aldehyde was used in toluene. Using 2-phenylcyclohexane-1,1-dimethanol obtained by hydrogenating hydrogen gas with% palladium / activated carbon as a catalyst, the present inventor synthesized the same procedure as above.

<Synthesis of Spiro [bicyclo [2.2.1] heptane-2,3'-oxetane] (NRBO)> CH
Di of butadiene and crotonaldehyde used during O synthesis
Instead of 6-methyl-3-cyclohexene-1,1-dimethanol obtained from the els-Alder reaction product, a reaction product of cyclopentadiene and acrolein, bicyclo [2.2.1] hept-5-ene. A completely similar reaction is carried out using bicyclo [2.2.1] heptane-1,1-dimethanol hydrogenated with hydrogen gas using 5% palladium / activated carbon as a catalyst in 1,1-dimethanol in toluene. As a result, the present inventors synthesized the same procedure as above.

<Examples 1 to 8 and Comparative Examples 1 to 3> First, the photocurability of the composition for optical adhesive was examined. An oxetane compound having the composition shown in Table 1 (the numerical values in the table are parts by mass),
Epoxy compounds, cationic photopolymerization initiators, etc. were mixed to obtain respective compositions for optical adhesives.

A photocurability test was carried out on each of the thus obtained compositions for optical adhesives as follows. The composition layer was applied onto a glass substrate so as to have a thickness of 100 μm. Then, the composition layer was cured by irradiating with a metal halide lamp at an output of 24 mW / cm ² for 10 seconds. The tackiness of the cured composition layer was examined with a fingertip, and the obtained results are shown in Table 1. Here, when there was no tack in the cured product layer, “◯” was given, when there was some tack, “Δ” was given, and when tack was present, “X” was given.

Although Examples 1 to 8 are mixtures of the alicyclic compound (a) having an oxetanyl group of the present invention and an epoxy compound, it is understood that the curability is excellent.

On the other hand, Comparative Example 1 was a composition containing only an epoxy compound, but was not cured at all and showed a remarkable tack. Comparative Examples 2 and 3 are examples in which an oxetane compound having no alicyclic structure was used as the oxetane compound. It was confirmed that the curability was improved as compared with the composition containing only the epoxy compound, but the curability was slightly inferior as compared with the examples in which the alicyclic compound (a) having an oxetanyl group of the present invention was mixed. Example 4 is a mixed example of the oxetane compound of the present invention and other oxetane compounds, but it was sufficiently cured. The curability of the alicyclic compound (a) having an oxetanyl group of the present invention is reflected. Example 5
In this example, a radical polymerizable compound and a radical polymerization initiator were mixed, but this example was also sufficiently cured.

As described above, it can be seen that the composition for an optical adhesive containing the alicyclic compound (a) having an oxetanyl group of the present invention has excellent curability.

Further, the obtained compositions for optical adhesives after being completely cured (further cured by irradiation with light)
Was measured for the D line of sodium at 25 ° C., and the results are shown in Table 1. Refractive index is Abbe
It was measured with a refractometer (Abbe refractometer type 1 manufactured by Atago Co., Ltd.). The refractive index can be changed from 1.465 to 1.568, and it was found that the refractive index can be adjusted as a composition for optical adhesives.

The Tg of the completely cured product of each composition shown in Table 1 (further cured by irradiation with light) was the same as that of the completely cured product of Comparative Example 1 when the Tg was 100%. 1-8
Indicates a temperature increase of 10% or more. Regarding the deflection temperature under load, when Comparative Example 1 was set to 100%,
Examples 1 to 8 show a temperature increase of 10% or more.
In addition, Tg is a temperature rising rate of 10 ° C./min, a measurement temperature RT to
Thermal analyzer EXSTAR DSC6200 at 200 ° C in a nitrogen stream (50 ml / min) according to JIS K7121 /
It was measured according to the DSC method. The deflection temperature under load was measured by an ASTM D648 method using an HDT tester S-3M apparatus at a stress of 1.80 MPs and a temperature rising rate of 120 ° C./h.

[0085]

[Table 1]

<Examples 9 to 11, Comparative Examples 4 to 6> The thermosetting properties of the compositions for optical adhesives were examined. Example 1
8, compositions for optical adhesives were prepared in the same manner except that the cationic photopolymerization initiator of Comparative Examples 1 to 3 was changed to SI-60L. The blending amount (parts by mass) is shown in Table 2.

A thermosetting test was conducted on each of the thus obtained compositions for optical adhesives as follows. Each composition was put in a sample bottle and immersed in an oil bath at 80 ° C. The thermosetting property of each composition after being cured for 1 minute was evaluated as follows. Those with almost no change in viscosity are “x”, those with increased viscosity are “Δ”, and those with complete curing are “◯”.

The results are shown in Table 2. The composition containing the alicyclic compound (a) having an oxetanyl group of the present invention has remarkably high thermosetting property as compared with the epoxy compound alone or other oxetane compounds.

Although it is possible to use thermosetting in the fixing portion of the optical connector, it is found that the composition for optical adhesive of the present invention has sufficient curability even in thermosetting. It was

[0090]

[Table 2]

[0091]

INDUSTRIAL APPLICABILITY The composition for optical adhesives containing the alicyclic compound (a) having an oxetanyl group of the present invention has high reactivity in both cases of photo-cationic curing and thermal cation-curing, and can be rapidly cured. You can proceed.

Further, the alicyclic compound (a) having an oxetanyl group of the present invention can change the refractive index by mixing with an epoxy compound or another oxetane compound, and thus an optical adhesive having a different refractive index. The agent composition can be prepared arbitrarily.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Sato             1-1-1, Onodai, Midori-ku, Chiba City, Chiba Prefecture             Showa Denko Co., Ltd. (72) Inventor Ryuji Kadota             1-1-1, Onodai, Midori-ku, Chiba City, Chiba Prefecture             Showa Denko Co., Ltd. F-term (reference) 4J005 AA04 AA07 BB02                 4J040 EE022 GA10 GA11 HB43                       HB44 HD18 HD21 HD30 JB08                       KA13 KA16 LA10 NA17

Claims (19)

[Claims] 1. A composition for an optical adhesive, which comprises an alicyclic compound (a) having at least one oxetanyl group in the molecule. 2. The optical adhesive according to claim 1, wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (1). Composition. [Chemical 1] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, otherwise is 1.) 3. A compound represented by the general formula (1) is 2-oxaspiro [3.5] non-6-ene or 5-methyl-
The composition for optical adhesives according to claim 2, which is 2-oxaspiro [3.5] non-6-ene. 4. The optical adhesive according to claim 1, wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (2). Composition. [Chemical 2] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, otherwise is 1.) 5. The compound according to claim 4, wherein the compound represented by the general formula (2) is 2-oxaspiro [3.5] nonane or 5-methyl-2-oxaspiro [3.5] nonane. The composition for optical adhesives of. 6. The optical adhesive according to claim 1, wherein the alicyclic compound (a) having at least one oxetanyl group in the molecule is a compound represented by the general formula (3). Composition. [Chemical 3] (In the formula, R is a hydrogen atom, or an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a halogenated alkyl group, m is an integer of 0 to 2, and n is 0. Is 2, otherwise is 1.) 7. A compound represented by the general formula (3) is 7,8-
Epoxy-5-methyl-2-oxaspiro [3.5] nonane, 6,7-epoxy-2-oxaspiro [3.5]
It is nonane, The composition for optical adhesives of Claim 6 characterized by the above-mentioned. 8. An alicyclic compound (a) having at least one oxetanyl group in the molecule is at least selected from compounds represented by general formula (1), general formula (2) and general formula (3). It is one kind, The composition for optical adhesives of Claim 1 characterized by the above-mentioned. 9. The composition for optical adhesives according to claim 1, further comprising a compound (b) having at least one epoxy group and not having an oxetanyl group. . 10. The composition for optical adhesives according to claim 9, wherein the compound (b) having at least one epoxy group and not having an oxetanyl group has a fluorine atom. 11. The composition for optical adhesives according to claim 1, further comprising a compound (c) which initiates cationic polymerization by irradiation with active energy rays and / or heating. . 12. The compound (c) which initiates cationic polymerization upon irradiation with active energy rays and / or heating is one or more selected from sulfonium salts, iodonium salts, phosphonium salts and diazonium salts. The composition for optical adhesives according to 1. 13. The composition for optical adhesives according to claim 1, which contains a radically polymerizable compound (d). 14. The composition for optical adhesives according to claim 1, further comprising a photoradical initiator (e). 15. A cured product of sodium D at 25 ° C.
The composition for optical adhesives according to any one of claims 1 to 14, wherein the refractive index with respect to a line is a value within the range of 1.40 or more and 1.70 or less. 16. An optical communication circuit formed by using the composition for optical adhesive according to claim 1. Description: 17. An optical communication material formed by using the composition for optical adhesive according to any one of claims 1 to 15. 18. An optical connector using the composition for optical adhesive according to any one of claims 1 to 15. 19. A composition for an optical adhesive comprising an alicyclic compound (a) having at least one oxetanyl group in the molecule and a compound (c) which initiates cationic polymerization by irradiation with active energy rays and / or heating. A method for producing an optical communication material, which comprises selectively irradiating the composition with an active energy ray to selectively cure the composition, and then performing a development treatment to remove an uncured portion.