JP2017061597A - An adhesive composition for optical communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition for optical communication having excellent adhesiveness and thermosetting properties.SOLUTION: An adhesive composition for optical communication comprises a compound (A) comprising an aromatic ring and a reactive silicon containing group, a (meth) acryl compound (B) comprising a cationic polymerizable functional group and a (meth) acryloyloxy group, a radical generator, and a cation generator that generates a cation at least by heat.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an adhesive composition for optical communication.

  In recent years, with the spread of the Internet, the importance of technology for increasing communication capacity has increased, and optical fiber networks have been expanded. In this optical communication system, an optical communication device in which an optical material and an optical element are bonded with, for example, an ultraviolet curable adhesive composition is used. Examples of the material such as the optical material include plastic and glass.

  On the other hand, Patent Document 1 discloses that an oligomer and / or monomer (A) having a (meth) acryloyl group and a hydroxyl group and having a number average molecular weight of 3000 or less averages at least hydrolyzable silyl groups in one molecule. Compound (B) having one compound, Compound (C) having an average of at least one polymerizable carbon-carbon double bond in one molecule other than (A), photopolymerization initiator (D), curing catalyst (E) , A light / moisture dual cure curable composition for FPD bonding, which describes that the composition can be cured by light, electron beam, or moisture.

JP 2012-153835 A

Under such circumstances, the present inventors prepared and evaluated an adhesive composition with reference to Patent Document 1, and when such an adhesive composition was cured by irradiation with ultraviolet rays, the adhesive composition It became clear that the adhesiveness was insufficient (Comparative Example 3).
From the above results, it was considered that when ultraviolet rays were blocked by an opaque member or the like during ultraviolet irradiation, the adhesive composition became poorly cured and the adhesiveness was further lowered.
It was also found that the adhesive composition may not be sufficiently cured even when an adhesive composition containing a compound having a (meth) acryloyl group or a hydrolyzable silyl group is heated (comparison) Examples 1, 2).
Then, an object of this invention is to provide the adhesive composition for optical communications excellent in adhesiveness and thermosetting.

As a result of intensive studies to solve the above problems, the present inventors have found that the composition is
A compound (A) having an aromatic ring and a reactive silicon-containing group;
(Meth) acrylic compound (B) having a cationic polymerizable functional group and a (meth) acryloyloxy group;
A radical generator,
The inventors have found that a predetermined effect can be obtained by containing at least a cation generator that generates cations by heat, and have reached the present invention.
The present invention is based on the above knowledge and the like, and specifically, solves the above problems by the following configuration.

1. A compound (A) having an aromatic ring and a reactive silicon-containing group;
(Meth) acrylic compound (B) having a cationic polymerizable functional group and a (meth) acryloyloxy group;
A radical generator,
An adhesive composition for optical communication, comprising at least a cation generator that generates cations by heat.
2. 2. The adhesive composition for optical communication according to 1 above, wherein the (meth) acrylic compound (B) further has a hydrocarbon group having 10 or less carbon atoms.
3. 3. The adhesive composition for optical communication according to 1 or 2 above, wherein the compound (A) further has an ion polymerizable functional group.
4). The compound (A) is a compound obtained by reacting an ion polymerizable functional group-containing compound with a compound having a reactive group that reacts with the ion polymerizable functional group. The adhesive composition for optical communication as described.
5. For the total content of the compound (A), the (meth) acrylic compound (B), the radical generator and the cation generator,
The content of the compound (A) is 30 to 50% by mass,
Content of the said (meth) acryl compound (B) is 10-60 mass%,
The content of the radical generator is 1 to 10% by mass,
The adhesive composition for optical communication according to any one of 1 to 4 above, wherein the content of the cation generator is 0.1 to 5% by mass.
6). The adhesive composition for optical communication according to any one of 1 to 5 above, further comprising a (meth) acryl compound (C) having no (meth) acryloyloxy group and having no cationic polymerizable functional group.
7). 7. The adhesive composition for optical communication according to 6, wherein the (meth) acrylic compound (C) further has an aromatic hydrocarbon group.
8). 8. The adhesive composition for optical communication according to 6 or 7 above, wherein the number of (meth) acryloyloxy groups contained in one molecule of the (meth) acrylic compound (C) is 1 to 3.
9. For the total content of the compound (A), the (meth) acrylic compound (B), the (meth) acrylic compound (C), the radical generator and the cation generator,
The content of the compound (A) is 30 to 50% by mass,
Content of the said (meth) acryl compound (B) is 10-40 mass%,
Content of the said (meth) acryl compound (C) is 10-40 mass%,
The content of the radical generator is 1 to 10% by mass,
The adhesive composition for optical communication according to any one of the above 6 to 8, wherein the content of the cation generator is 0.1 to 5% by mass.
10. 10. The adhesive composition for optical communication according to any one of 1 to 9 above, wherein the radical generator is a photo radical generator.

  The adhesive composition for optical communication of the present invention is excellent in adhesiveness and thermosetting.

FIG. 1 is a cross-sectional view schematically showing a laminate used in the step of curing the composition of the present invention. FIG. 2 is a perspective view schematically showing an example of a usage mode of the composition of the present invention.

The present invention will be described in detail below.
In this specification, (meth) acrylate represents acrylate or methacrylate, (meth) acryloyl represents acryloyl or methacryloyl, and (meth) acryl represents acryl or methacryl.
In addition, a numerical range expressed using “to” in this specification means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In this specification, when a component contains 2 or more types of substances, the content of the above components refers to the total content of two or more types of substances.
In the present specification, what is more excellent in at least one of adhesiveness and thermosetting may be more excellent in the effect of the present invention.

[Adhesive composition for optical communication]
The adhesive composition for optical communication of the present invention (the composition of the present invention)
A compound (A) having an aromatic ring and a reactive silicon-containing group;
(Meth) acrylic compound (B) having a cationic polymerizable functional group and a (meth) acryloyloxy group;
A radical generator,
It is an adhesive composition for optical communication containing at least a cation generator that generates cations by heat.

Since the composition of this invention takes such a structure, it is thought that a desired effect is acquired. The reason is not clear, but it is presumed that it is as follows.
In the composition of the present invention, the (meth) acrylic compound (B) has a cationic polymerizable functional group, and the composition of the present invention contains a cation generator that generates a cation at least by heat. This composition can be cured by heat and is considered to have excellent adhesion.
Moreover, when the said (meth) acrylic compound (B) has a (meth) acryloyloxy group, the composition of this invention can be hardened | cured with active energy rays, such as an ultraviolet-ray.
Furthermore, the composition of the present invention can be moisture-cured by containing the compound (A) having an aromatic ring and a reactive silicon-containing group.
It is considered that the composition of the present invention is excellent in a desired effect by such curing by a plurality of means.
Hereinafter, each component contained in the composition of this invention is explained in full detail.

<Compound (A)>
The compound (A) contained in the composition of the present invention is not particularly limited as long as it is a compound having an aromatic ring and a reactive silicon-containing group.

Although it does not restrict | limit especially as said aromatic ring, It is preferable that it is a C6-C20 aromatic ring. The aromatic ring may have a halogen atom such as chlorine or bromine.
Specific examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, a biphenyl ring, a bisphenol ring, and a terphenyl ring. May be linked). Among these, a bisphenol ring, a biphenyl ring, a naphthalene ring, and a fluorene ring are preferable, and a bisphenol ring is more preferable.

In the bisphenol ring, the two benzene rings may be connected by any connecting group. Examples of the linking group include —C (CH ₃ ) ₂ —, —CH ₂ —, —SO ₂ —, and —C (CF ₃ ) ₂ —.

Examples of the bisphenol ring include bisphenol A type, bisphenol F type, halogenated bisphenol A type, bisphenol S type, and bisphenol AF type.
Among these, bisphenol A type and bisphenol F type are preferable, and bisphenol A type is more preferable in that the effects of the present invention are more excellent and the heat and heat resistance is excellent.

  The reactive silicon-containing group has 1 to 3 reactive groups bonded to a silicon atom. The reactive silicon-containing group can be crosslinked by causing a reaction by using a catalyst or the like, if necessary, in the presence of moisture or a crosslinking agent. Examples of the reactive silicon-containing group include a halogenated silicon-containing group, a silicon hydride-containing group, and a hydrolyzable silicon-containing group. Of these, hydrolyzable silicon-containing groups are preferred.

  The hydrolyzable silicon-containing group has 1 to 3 hydroxy groups and / or hydrolyzable groups bonded to a silicon atom. Examples of hydrolyzable silicon-containing groups include hydrolyzable silyl groups such as alkoxysilyl groups, alkenyloxysilyl groups, acyloxysilyl groups, aminosilyl groups, aminooxysilyl groups, oximesilyl groups, and amidosilyl groups. . Specifically, an alkoxysilyl group, an alkenyloxysilyl group, an acyloxysilyl group, an aminosilyl group, an aminooxysilyl group, an oximesilyl group, an amidosilyl group and the like exemplified by the following formula are preferably used.

Of these, an alkoxysilyl group is preferred because it is easy to handle.
Although the alkoxy group couple | bonded with the silicon atom of an alkoxy silyl group is not specifically limited, Since acquisition of a raw material is easy, a methoxy group, an ethoxy group, or a propoxy group is mentioned suitably.
The group other than the alkoxy group bonded to the silicon atom of the alkoxysilyl group is not particularly limited, for example, a hydrogen atom or an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, An alkenyl group or an arylalkyl group is preferable.

  The number of reactive silicon-containing groups contained in one molecule of the compound (A) is one or more, and preferably one or two.

In the compound (A), the aromatic ring and the reactive silicon-containing group can be bonded to a hydrocarbon group. The above hydrocarbon groups can have heteroatoms.
The hydrocarbon group is not particularly limited. For example, an aliphatic hydrocarbon group (which may be linear, branched or cyclic), an aromatic hydrocarbon group, or a combination thereof may be mentioned. The hydrocarbon group may have an unsaturated bond.
The hetero atom is not particularly limited. For example, an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen are mentioned. Heteroatoms may form functional groups by combining heteroatoms or heteroatoms with carbon atoms and / or hydrogen atoms. Examples of the functional group include a hydroxy group. Moreover, the carbon atom which forms a hydrocarbon group may be substituted with a hetero atom.

It is preferable that the compound (A) further has an ion polymerizable functional group from the viewpoint that it is excellent due to the effects of the present invention and is excellent in heat and humidity resistance.
An ion polymerizable functional group is a functional group capable of ion polymerization. Ionic polymerization is a chain polymerization reaction using ions as growth active species.
Examples of the ion polymerizable functional group include a cationic polymerizable functional group and an anion polymerizable functional group.
The ion polymerizable functional group is preferably a cationic polymerizable functional group. The cationic polymerizable functional group is a functional group capable of cationic polymerization (cation polymerization).
The cationically polymerizable functional group preferably has a cyclic ether structure. Examples of the structure of the cyclic ether include an epoxy skeleton and an oxetane skeleton.
Examples of the cationic polymerizable functional group include an epoxy group, an oxetanyl group; and a group having a cationic polymerizable functional group.

Examples of the group having a cationic polymerizable functional group include a group in which a hydrocarbon group is bonded to the cationic polymerizable functional group. When a hydrocarbon group is bonded to the cyclic ether, another end of the hydrocarbon group may be bonded to the cyclic ether to form another cyclic structure.
Examples of the group having a cationic polymerizable functional group include an epoxycyclohexyl group.

In the compound (A), the ion polymerizable functional group can be bonded to the aromatic ring directly or via a hydrocarbon group which may have a hetero atom. The reactive silicon-containing group can be similarly bonded.
A hydrocarbon group and a hetero atom are not particularly limited. For example, the thing similar to the above is mentioned.
When the ion polymerizable functional group is an epoxy group, the epoxy group can be bonded to the aromatic ring as a glycidyloxy group, for example.

(Preferred embodiment)
The compound (A) is preferably a compound obtained by reacting an ion polymerizable functional group-containing compound with a compound having a reactive group that reacts with the ion polymerizable functional group.

The ion polymerizable functional group-containing compound used for the production of the compound (A) is not particularly limited as long as it is a compound having an ion polymerizable functional group. The ion polymerizable functional group is the same as described above.
The compound having a reactive group that reacts with the ion-polymerizable functional group used for the production of the compound (A) is hereinafter referred to as a compound (g).

In the present invention, one or both of the ion polymerizable functional group-containing compound and the compound (g) may have an aromatic ring.
One or both of the ion-polymerizable functional group-containing compound and the compound (g) may have a reactive silicon-containing group.

The ion polymerizable functional group-containing compound is preferably an epoxy compound. The epoxy compound used for the production of the compound (A) is hereinafter referred to as an epoxy compound (f).
The epoxy compound (f) is not particularly limited as long as it is a compound having at least one epoxy group. The epoxy compound (f) preferably has 2 or more and 10 or less epoxy groups in one molecule.
In the epoxy compound (f), the epoxy group can be bonded to a hydrocarbon group. The hydrocarbon group is as defined above.

The epoxy compound (f) is preferably an aromatic epoxy compound having an aromatic ring or an epoxy silane.
The aromatic epoxy compound is not particularly limited as long as it is an epoxy compound having an aromatic ring and an epoxy group. The aromatic epoxy compound is preferably an aromatic epoxy resin having a plurality of epoxy groups.

  Examples of the aromatic epoxy compound include bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, pyrocatechol, resorcinol, cresol novolak, tetrabromobisphenol A, trihydroxybiphenyl, bisresorcinol, bisphenol hexa Glycidyl ether type obtained by reaction of polyphenol such as fluoroacetone, tetramethylbisphenol F, bixylenol, dihydroxynaphthalene and epichlorohydrin; glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, polyethylene Aliphatic polyhydric alcohols such as glycol and polypropylene glycol Polyglycidyl ether type obtained by reaction with picrohydrin; glycidyl ether ester type obtained by reaction of hydroxycarboxylic acid such as p-oxybenzoic acid and β-oxynaphthoic acid with epichlorohydrin; phthalic acid, methylphthalic acid, isophthalic acid, Polyglycidyl ester type derived from polycarboxylic acids such as terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid, trimellitic acid, polymerized fatty acid; aminophenol, Glycidylaminoglycidyl ether type derived from aminoalkylphenol, etc .; Glycidylaminoglycidyl ester type derived from aminobenzoic acid; aniline, toluidine, tribromoanilyl Glycidylamine type derived from styrene, xylylenediamine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, etc .; epoxidized polyolefin, glycidylhydantoin, glycidylalkylhydantoin And triglycidyl cyanurate.

The epoxy silane is not particularly limited as long as it is a silane coupling agent having an epoxy group and a reactive silicon-containing group. An example is glycidyloxyalkylalkoxysilane such as glycidyloxypropyltrimethoxysilane.
An epoxy compound (f) can be used individually or in combination of 2 types or more, respectively.

The compound (g) is not particularly limited as long as it is a compound having a reactive group that reacts with an ion polymerizable functional group (for example, an epoxy group).
Specific examples of reactive groups that react with ion-polymerizable functional groups (for example, epoxy groups) include amino groups (—NH ₂ ), imino groups (═NH, —NH—), ureido groups, mercapto groups, acid anhydrides. Groups and the like. Of these, an amino group and an imino group are preferable.
Examples of the compound (g) include a silane coupling agent having a reactive group that reacts with an ion polymerizable functional group and a reactive silicon-containing group, and an amine compound having an aromatic ring. The amine compound having an aromatic ring is preferably a polyamine compound having a plurality of at least one selected from the group consisting of an amino group and an imino group.

  Examples of the silane coupling agent include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylethyldiethoxysilane, bistrimethoxysilylpropylamine, and bistriethoxy. Silylpropylamine, bismethoxydimethoxysilylpropylamine, bisethoxydiethoxysilylpropylamine, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N -Β (aminoethyl) γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylethyldiethoxysilane, 3,3-dimethyl-4-aminobutyltrimethoxysilane, 3,3-di Aminosilane compounds such as til-4-aminobutylmethyldimethoxysilane; (N-cyclohexylaminomethyl) methyldiethoxysilane, (N-cyclohexylaminomethyl) triethoxysilane, (N-phenylaminomethyl) methyldimethoxysilane, (N -Iminosilane compounds such as phenylaminomethyl) trimethyloxysilane, a compound represented by the following formula (1), and N-phenyl-3-aminopropyltrimethoxysilane represented by the following formula (2);

  Ureidosilane compounds such as γ-ureidopropyltrimethoxysilane; mercaptosilane compounds such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane Etc.

The polyamine compound having an aromatic ring is a compound having an aromatic ring and at least one selected from the group consisting of an amino group and an imino group, and the number of amino groups and the like is plural per molecule of the polyamine compound.
The aromatic ring has the same meaning as above.
Examples of the polyamine compound include methylene dianiline and diaminobenzene.
A compound (g) may be used independently and may use 2 or more types together.

  The equivalent of the reactive group (reactive group / ionic polymerizable functional group) of the compound (g) with respect to the ion polymerizable functional group (for example, epoxy group) of the ion polymerizable functional group-containing compound has the effect of the present invention. It is preferably 0.1 to 1.0, more preferably 0.6 to 0.8 in terms of more excellent and heat and moisture resistance.

  Examples of the combination of the ion polymerizable functional group-containing compound and the compound (g) include an aromatic ring having an aromatic ring and at least one functional group selected from the group consisting of an epoxy group, an amino group, and an imino group. A combination of a compound (a compound having an aromatic ring and a functional group) and a silane coupling agent (silane coupling agent) having a reactive group capable of reacting with the functional group and a reactive silicon-containing group can be given. Specifically, for example, a combination of an aromatic epoxy resin and a silane coupling agent having a reactive group capable of reacting with an epoxy group and a reactive silicon-containing group (1); an epoxy silane and a polyamine having an aromatic ring The combination (2) with a compound is mentioned.

  When the combination of the ion-polymerizable functional group-containing compound and the compound (g) is (1) above, the equivalent of the reactive group of the silane coupling agent to the epoxy group of the aromatic epoxy resin (reactive group) / Epoxy group) is preferably from 0.1 to 1.0, more preferably from 0.6 to 0.8, in that the effects of the present invention are more excellent and the heat and moisture resistance is excellent.

  When the combination of the ion polymerizable functional group-containing compound and the compound (g) is the above (2), the epoxysilane has an amino group and / or an imino group (reactive group) of the polyamine compound having an aromatic ring. The equivalent of the epoxy group (epoxy group / reactive group) is preferably 0.1 to 2.0, more preferably 0.6 to 1.6 in that the effect of the present invention is more excellent and the heat and moisture resistance is excellent. More preferably.

As a manufacturing method of a compound (A), the method of stirring an ion-polymerizable functional group containing compound and a compound (g) at 100-140 degreeC in inert gas atmosphere like nitrogen gas is mentioned, for example.
A compound (A) can be used individually or in combination of 2 types or more, respectively.

  When the ion-polymerizable functional group-containing compound has two ion-polymerizable functional groups (for example, epoxy groups), the compound (A) is obtained by reacting two molecules of the ion-polymerizable functional group-containing compound and the compound (g). The compound may contain at least one selected from the group consisting of a compound and a compound obtained by reacting one molecule of the ion polymerizable functional group-containing compound and the compound (g).

<(Meth) acrylic compound (B)>
The (meth) acrylic compound (B) contained in the composition of the present invention is not particularly limited as long as it is a compound having a cationic polymerizable functional group and a (meth) acryloyloxy group.

The cationic polymerizable functional group that the (meth) acrylic compound (B) has is the same as the cationic polymerizable functional group that the compound (A) can have.
The number of cationically polymerizable functional groups possessed by one molecule of the (meth) acrylic compound (B) is preferably 1 to 4.
The (meth) acrylic compound (B) has a cationic polymerizable functional group, a group having an epoxy skeleton such as a glycidyl group, a glycidyloxy group, and an epoxycyclohexyl group; an oxetane such as a 3-alkyloxetane-3-yl group. It is mentioned as one of the preferable aspects to have as group which has frame | skeleton.

  The number of (meth) acryloyloxy groups contained in one molecule of the (meth) acrylic compound (B) is preferably 1 to 4.

The (meth) acrylic compound (B) can further have a hydrocarbon group that may have a hetero atom. In the (meth) acrylic compound (B), one preferred embodiment is that the cationic polymerizable functional group and the (meth) acryloyloxy group are bonded via the hydrocarbon group.
A hetero atom and a hydrocarbon group are the same as described above.
Especially, the hydrocarbon group which may have a hetero atom is an aliphatic hydrocarbon group (which may be linear, branched or cyclic) from the viewpoint of excellent flexibility. Preferably, it is a linear aliphatic hydrocarbon group.
The hydrocarbon group preferably has 1 to 10 carbon atoms.

  Examples of the (meth) acrylic compound (B) include epoxy compounds such as hydroxyalkyl (meth) acrylate glycidyl ether, glycidyl (meth) acrylate, and 3,4-epoxycyclohexylmethyl (meth) acrylate; (3-ethyloxetane Examples include oxetane compounds such as (3-yl) methyl acrylate and (3-ethyloxetane-3-yl) methyl methacrylate represented by the following formula.

Examples of the hydroxyalkyl (meth) acrylate glycidyl ether include hydroxymethyl (meth) acrylate glycidyl ether, hydroxyethyl (meth) acrylate glycidyl ether, hydroxypropyl (meth) acrylate glycidyl ether, and hydroxybutyl acrylate glycidyl represented by the following formula: Examples include ether, hydroxybutyl methacrylate glycidyl ether, and hydroxyhexyl (meth) acrylate glycidyl ether.

The (meth) acrylic compound (B) can be used alone or in combination of two or more.
The (meth) acrylic compound (B) is not particularly limited with respect to its production method. For example, a conventionally well-known thing is mentioned.

<Radical generator>
The radical generator contained in the composition of the present invention is not particularly limited as long as it is a compound that generates radicals.
The radical generator can generate a radical by at least one selected from the group consisting of light and heat, for example.
The radical generator is preferably a photoradical generator capable of generating radicals by at least light.

Examples of the radical generator include acetophenone compounds, benzoin ether compounds, benzophenone compounds, sulfur compounds, azo compounds, peroxide compounds, phosphine oxide compounds, and the like.
Specifically, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone, p-methoxybenzophenone, diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone , Methylphenylglyoxylate, ethylphenylglyoxylate, 4,4'-bis (dimethylaminobenzophenone), 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1, Carbonyl compounds such as 2-diphenylethane-1-one and 1-hydroxycyclohexyl phenyl ketone; Sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; Azobis Sobuchironitoriru, azo compounds such as azobis-2,4-dimethylvaleronitrile; benzoyl peroxide, peroxide compounds such as di -t- butyl peroxide and the like.

Among them, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl -1-Propan-1-one is preferred.
The radical generators can be used alone or in combination of two or more.

<Cation generator>
The cation generator contained in the composition of the present invention is not particularly limited as long as it is a cation generator that generates cations by at least heat. The cation generator that generates cations by heat is also called a thermal cation generator, a thermal cation curing catalyst, a thermal acid generator, a thermal curing agent, or a cationic polymerization initiator. Hereinafter, the cation generator contained in the composition of the present invention may be referred to as a thermal cation generator.
The thermal cation generator may be capable of generating cations by irradiating ultraviolet rays in addition to heat.

Examples of the thermal cation generator include a compound represented by the following formula (5).
^{_{(R 5 c R 6 d R}} 7 e R 8 f Z) s + (AXt) s- (5)
In formula (5), Z represents at least one element selected from the group consisting of S, Se, Te, P, As, Sb, Bi, O, N, and a halogen element.
R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and represent an organic group.
c, d, e, and f are each 0 or a positive number, and the sum of c, d, e, and f is equal to the valence of Z.
A represents a metal element or a metalloid element (metalloid), and at least one selected from the group consisting of B, P, As, Sb, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, and Co. One.
X represents a halogen element.
t is the number of halogen elements. t is preferably 4-6.
s is the valence of the ion. s can be 1 or 2 or more.

Specific examples of the anion (AXt) ^s- of the above formula (5) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarce. Nate (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ) and the like.
In the above formula (5), examples of the anion instead of (AXt) ^s- include an anion represented by the formula AXt (OH) ^- .
Other anions that the thermal cation generator can have include, for example, perchlorate ion (ClO ₄ ⁻ ), trifluoromethylsulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), Toluenesulfonic acid ions, trinitrobenzenesulfonic acid ions, and the like.

Specific examples of the thermal cation generator include aromatic sulfonium salts represented by the following formula (6).

In formula (6), R ¹ , R ² and R ³ each represents an organic group.

  Specific examples of the thermal cation generator include diazonium salt types such as AMERICURE series (American Can), ULTRASET series (Adeka), WPAG series (Wako Pure Chemical Industries); UVE series (General electric), FC series (manufactured by 3M), UV9310C (manufactured by GE Toshiba Silicone), Photoinitiator 2074 (manufactured by Rhone-Poulenc), WPI series (manufactured by Wako Pure Chemical Industries), etc .; CYRACURE series (Union Carbide), UVI series (General Electric), FC series (3M), CD series (Sartomer), Optmer SP series / Optomer CP series (Adeka), Sun Ido SI series (Sanshin Chemical Industry Co., Ltd.), CI series (manufactured by Nippon Soda Co., Ltd.), WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.), CPI series (manufactured by San-Apro Ltd.) sulfonium salt type or the like, and the like. The aromatic sulfonium salt represented by the above formula (6) is available, for example, as the Sun Aid SI series.

  The cation generators can be used alone or in combination of two or more.

(Content of each component)
In the present invention, the content of the compound (A) is the sum of the contents of the compound (A), the (meth) acrylic compound (B), the radical generator and the thermal cation generator from the viewpoint that the effect of the present invention is superior. (The above total is sometimes referred to as the total (i).) 30 to 50% by mass is preferable, and 30 to 40% by mass is more preferable.
For the same reason as the content of the compound (A), the content of the (meth) acrylic compound (B) is preferably 10 to 60% by mass, and 15 to 50% by mass with respect to the total (i). More preferred.
For the same reason as the content of the compound (A), the content of the radical generator is preferably 1 to 10% by mass and more preferably 2 to 8% by mass with respect to the total (i).
For the same reason as the content of the compound (A), the content of the thermal cation generator is preferably 0.1 to 5% by mass, and 0.5 to 3% by mass with respect to the total (i). More preferred.

((Meth) acrylic compound (C))
The composition of the present invention is superior in terms of the effects of the present invention, and is excellent in adhesiveness, and further has a (meth) acrylic compound (C) having no (meth) acryloyloxy group without a cationically polymerizable functional group. It is mentioned as one of the preferable aspects that contain.

  The number of (meth) acryloyloxy groups contained in one molecule of the (meth) acrylic compound (C) is preferably 1 to 3 in that the effects of the present invention are more excellent and the adhesiveness is excellent.

  The cationic polymerizable functional group that the (meth) acrylic compound (C) does not have is the same as the cationic polymerizable functional group that the (meth) acrylic compound (B) has.

From the viewpoint that the (meth) acrylic compound (C) is excellent due to the effects of the present invention and is excellent in heat-and-moisture resistance, one preferred embodiment is that it further has an aromatic hydrocarbon group.
When the (meth) acrylic compound (C) further has an aromatic hydrocarbon group, the aromatic ring of the compound (A) and the aromatic hydrocarbon group of the (meth) acrylic compound (C) interact with each other by π-π interaction. By performing (π-π stacking interaction), the shear force of the obtained adhesive layer is increased, and it is considered that the adhesiveness is superior.
The aromatic hydrocarbon group is not particularly limited. Examples thereof include a phenyl group and a phenylene group. The aromatic hydrocarbon group may have a substituent. The substituent is not particularly limited.

In addition, the aromatic hydrocarbon group may be a group in which two aromatic hydrocarbon groups are bonded via an aliphatic hydrocarbon group, for example. The aliphatic hydrocarbon group is not particularly limited. For example, the thing similar to the above is mentioned.
As said group, group represented by a following formula is mentioned, for example. In the formula, * indicates a bonding position.

In the (meth) acrylic compound (C), the (meth) acryloyloxy group and the aromatic hydrocarbon group can be bonded via, for example, a hydrocarbon group that may have a hetero atom.
A hetero atom and a hydrocarbon group are the same as described above.
Examples of the hydrocarbon group that may have a hetero atom include, for example, an aliphatic hydrocarbon group (preferably a linear or branched aliphatic hydrocarbon group), an oxyalkylene group (an oxyalkylene group is a monooxyalkylene group). And a polyoxyalkylene group), and a hydrocarbon group having a urethane bond or a urea bond.
As for carbon number of an oxyalkylene group, 1-10 are preferable.
Examples of the oxyalkylene group include a methyleneoxy group, an ethyleneoxy group, and a propyleneoxy group.
The number of repeating units of the oxyalkylene group can be 1-20.

As the (meth) acrylic compound (C), for example, a compound having an oxyalkylene group (one or more) such as bisphenol A alkyleneoxy-modified di (meth) acrylate and phenoxyalkyl (meth) acrylate;
Aromatic urethane (meth) acrylates; and alicyclic (meth) acrylates such as isobornyl (meth) acrylate.
Examples of the bisphenol A alkyleneoxy-modified di (meth) acrylate include bisphenol A ethyleneoxy-modified diacrylate represented by the following formula (wherein m is 1 to 10 and n is 1 to 10), bisphenol A. Examples thereof include ethyleneoxy-modified dimethacrylate and bisphenol A propyleneoxy-modified di (meth) acrylate.

The (meth) acrylic compound (C) can be used alone or in combination of two or more.

(Content of each component when further containing (meth) acrylic compound (C))
The content of the compound (A) is such that the effects of the present invention are more excellent and the heat and moisture resistance is excellent, and the compound (A), (meth) acrylic compound (B), (meth) acrylic compound (C), radical generator And 30-50% by mass, and more preferably 35-45% by mass with respect to the total content of the thermal cation generator (hereinafter, this total may be referred to as total (ii)).
The content of the (meth) acrylic compound (B) is preferably 10 to 40% by mass and more preferably 15 to 30% by mass for the same reason as the content of the compound (A).
The content of the (meth) acrylic compound (C) is preferably 10 to 40% by mass and more preferably 30 to 40% by mass for the same reason as the content of the compound (A).
The content of the radical generator is preferably 1 to 10% by mass and more preferably 2 to 8% by mass for the same reason as the content of the compound (A).
The content of the cation generator is preferably from 0.1 to 5 mass%, more preferably from 0.5 to 3 mass%, for the same reason as the content of the compound (A).

(Additive)
The composition of the present invention may further contain an additive. Examples of the additive include a compound having an anion polymerizable functional group, a photocation generator, an anion generator, and a curing catalyst (for example, a reaction of a reactive silicon-containing group (for example, a hydrolyzable silicon-containing group)). For example, those that can accelerate hydrolysis / condensation reaction), antioxidants, antioxidants, adhesion-imparting agents, silane coupling agents, plasticizers, dispersants, and coloring agents. The content of the additive can be appropriately selected.

-Curing catalyst It is preferable that the composition of this invention contains a curing catalyst further from a viewpoint that it is excellent with a predetermined effect.
The curing catalyst can promote a reaction of a reactive silicon-containing group (for example, a hydrolysis / condensation reaction of a hydrolyzable silicon-containing group).

Examples of the curing catalyst include oxides, hydroxides, carboxylates, and complexes of at least one metal selected from the group consisting of tin, zirconium, and titanium.
The carboxylic acid that forms the metal carboxylate is not particularly limited. Examples include acetic acid, octylic acid, oleic acid, and lauric acid.
The ligand for forming the metal complex is not particularly limited. Examples include acetylacetonate; alkyl acetoacetates such as ethyl acetoacetate.

The curing catalyst is preferably at least one curing catalyst selected from the group consisting of a tin-based catalyst, a zirconium-based catalyst, and a titanium-based catalyst, more preferably a zirconium-based catalyst, and a zirconium complex or carboxylate. More preferably.
Examples of the zirconium complex include zirconium acetylacetonate. Examples of zirconium acetylacetonate include zirconium monoacetylacetonate and zirconium toterraacetylacetonate.
Examples of tin carboxylates include dialkyltin dicarboxylates such as dibutyltin dilaurate and dioctyltin dilaurate.
The curing catalysts can be used alone or in combination of two or more.

  The content of the curing catalyst is the total amount of the compound (A) and the (meth) acrylic compound (B) (when the composition of the present invention further contains a (meth) acrylic compound (C), the compound (A), The total amount of (meth) acrylic compound (B) and (meth) acrylic compound (C) is preferably 0.05 to 2.0% by mass.

(Method for producing the composition of the present invention)
The composition of the present invention is not particularly limited with respect to its production method. For example, it can be produced by mixing the above components.

(Curing of the composition of the present invention)
The composition of the present invention can be cured by heating.
The composition of the present invention may be cured by irradiating active energy rays such as ultraviolet rays.

  When the composition of the present invention is cured by heating, the heating temperature is preferably 90 to 140 ° C, more preferably 90 to 120 ° C.

When the composition of the present invention is cured by ultraviolet irradiation, the irradiation amount (integrated light amount) of ultraviolet rays used when curing the composition of the present invention is preferably 300 to 1000 mJ / cm ² . The apparatus used for irradiating ultraviolet rays is not particularly limited. For example, a conventionally well-known thing is mentioned.

  The composition of the present invention can be cured by moisture. The relative humidity at the time of curing is preferably 50 to 98% RH.

  As a method for curing the composition of the present invention, from the viewpoint of excellent adhesiveness, for example, one preferred embodiment is to heat the composition of the present invention after being irradiated with ultraviolet rays.

A method for curing the composition of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view schematically showing a laminate used in the step of curing the composition of the present invention.
Fig.1 (a) is a figure which shows the process (ultraviolet irradiation process) of irradiating a laminated body which uses the composition of this invention with an ultraviolet-ray.
In FIG. 1A, the laminated body 10 includes a base material 12, members 16 and 18 having a light shielding property, a transparent member 20, and a composition 14. As the composition 14, the composition of the present invention (before curing) is used.
The laminated body 10 is irradiated with ultraviolet rays 22.

FIG.1 (b) is sectional drawing of the laminated body after an ultraviolet irradiation process.
In FIG.1 (b), the composition 28 under the transparent member 20 hardens | cures by irradiation of an ultraviolet-ray.
On the other hand, since the member 16 is light-shielding, the composition 24 under the member 16 is not sufficiently irradiated with ultraviolet rays, and the composition 24 remains uncured. The same applies to the composition 26 under the member 18.

FIG.1 (c) is a figure which shows the heating process which heats the laminated body after ultraviolet irradiation.
In FIG. 1C, the compositions 24 and 26 can be cured by applying heat 30 to the laminate 10. The composition 28 can be further cured by a heating process.

FIG.1 (d) is sectional drawing of the laminated body after a heating process.
In FIG. 1 (d), the composition 14 is sufficiently cured to bond the substrate 12 to the members 16 and 18 and the transparent member 20.

  The thickness of the adhesive layer obtained by curing the composition of the present invention is preferably 0.01 to 0.05 mm.

(Adherent)
The material of the adherend to which the composition of the present invention can be applied is not particularly limited. For example, plastic, rubber, glass, metal, ceramic and the like can be mentioned.
The method for applying the composition of the present invention to an adherend is not particularly limited.

(Use)
The composition of the present invention can be used as an adhesive for adhering optical materials.
Examples of the optical material include an optical fiber, a fiber array, an optical waveguide, a lens, a filter, a diffraction grating, and an optical active element.
Especially, it is preferable to adhere | attach a fiber array and an optical waveguide.
The fiber array is not particularly limited.
The optical waveguide is not particularly limited. An example is a PLC (planar optical waveguide circuit).
An optical communication device such as an optical waveguide device can be produced by bonding an optical waveguide with the composition of the present invention.

-Optical waveguide device An example of the use aspect of the composition of this invention is demonstrated using attached drawing. The present invention is not limited to the attached drawings.
FIG. 2 is a perspective view schematically showing an example of a usage mode of the composition of the present invention.
In FIG. 2, the optical waveguide device 40 includes a fiber array 42 and an optical waveguide 43. The fiber array 42 has an optical fiber 41. The fiber array 42 and the optical waveguide 43 are bonded and connected via an adhesive layer 44.
The composition of the present invention is used for the adhesive layer 44.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.

<Synthesis of Compound (A)>
Each component shown in the following Table 1 is mixed in the composition (part by mass) shown in the same table, and stirred at 120 ° C. for 8 hours in an inert gas atmosphere to have an aromatic ring and a reactive silicon-containing group. Compounds A1 to A4, which are compounds (A), were obtained.

Details of each component in Table 1 are as follows.
Epoxy compound f1: Epototo YD-128 (bisphenol A diglycidyl ether, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) (hereinafter structure)

Epoxy compound f2: Epototo YDF-170 (bisphenol F diglycidyl ether, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) (hereinafter structure)

-Iminosilane compound g1: Alink-15 (N-ethyl-3-aminoisobutyltrimethoxysilane, manufactured by Momentive Performance Materials) (hereinafter referred to as structure)

  In Table 1, “reactive group / epoxy group” represents the molar ratio [imino group / epoxy group] of the imino group of the iminosilane compound g1 to the epoxy group of the epoxy compounds f1 to f2.

  When one molecule of the epoxy compound f1 and one molecule of the iminosilane compound g1 are reacted, a compound represented by the following formula (I) is obtained.

(I)

  When 1 molecule of the epoxy compound f1 and 2 molecules of the iminosilane compound g1 are reacted, a compound represented by the following formula (II) is obtained.

(II)

  When one molecule of the epoxy compound f2 and one molecule of the iminosilane compound g1 are reacted, a compound represented by the following formula (III) is obtained.

(III)

  When one molecule of the epoxy compound f2 and two molecules of the iminosilane compound g1 are reacted, a compound represented by the following formula (IV) is obtained.

(IV)

<Preparation of adhesive composition>
Each component shown in the following Table 2 was mixed in the composition (parts by mass) shown in the same table and stirred using a stirrer to prepare adhesive compositions of Examples and Comparative Examples.

<Evaluation>
The following evaluation was performed using the adhesive composition produced as described above. The results are shown in Table 2.
(Initial shear strength)
-Preparation of test body Prepare two sheets made of soda-lime glass (length 30 mm x width 25 mm x thickness 5 mm) as a base material, and apply the adhesive composition prepared as described above to one sheet, Another plate was laminated and pressure-bonded thereto to obtain a laminate. At that time, the two substrates were stacked so that the adhesive layer made of the adhesive composition had a length of 5 mm, a width of 25 mm, and a thickness of 0.03 mm.

-Curing by ultraviolet rays and heat Using an ultraviolet irradiation device (trade name CSOT-40A, manufactured by GS Yuasa), the laminate obtained as described above was subjected to 700 to 900 mJ under the conditions of 23 ° C and 60% relative humidity. / Cm ² of ultraviolet light was irradiated, and then the laminate was placed at 90 ° C. for 1 hour to cure the adhesive composition to prepare a test specimen. The thickness of the adhesive layer after curing was 0.03 mm.

-Measurement of initial shear strength The initial shear strength was measured under the conditions of a tensile rate of 3 mm / min and 23 ° C using the test specimen prepared as described above in accordance with JIS K6852-1994.
The greater the initial shear strength, the better the adhesion. In the present invention, when the initial shear strength is 30 kgf / cm ² or more, the adhesiveness is excellent.

(Shear strength after wet heat degradation)
The same specimen as that prepared at the initial shear strength was placed in an environment of 80 ° C. and 95% relative humidity for 10 days to cause wet heat degradation.
The shear strength after wet heat deterioration was measured in the same manner as the initial shear strength using the test body after wet heat deterioration.

(Thermosetting)
-Preparation of test body A sheet made of soda-lime glass (length 30 mm x width 25 mm x thickness 5 mm) was prepared as a base material, and the adhesive composition prepared as described above was used as an adhesive layer of the adhesive composition. Was applied to the plate so that the length was 5 mm × width 25 mm × thickness 0.03 mm, and the adhesive composition was cured by placing it at 100 ° C. for 2 hours to prepare a test specimen.

-Evaluation of thermosetting The thermosetting property of the test body obtained as described above was evaluated by touch.
When the cured product of the adhesive composition is not sticky, it can be said that it is excellent in thermosetting, and thus this is indicated as “A”.
When the cured product of the adhesive composition is sticky, it can be said that the thermosetting property is bad, and this is indicated as “B”.
When the adhesive composition after being placed under a condition of 100 ° C. for 2 hours is in a liquid state, it can be said that the thermosetting property is very bad, so this is indicated as “C”.

Details of each component in Table 2 are as follows.
Compounds A1 to A4: Compounds A1 to A4 synthesized as described above

・ (Meth) acrylic compound B1: 4-hydroxybutyl acrylate glycidyl ether (structure shown below), trade name 4HBAGE, manufactured by Nippon Kasei Co.

-(Meth) acrylic compound B2: (3-ethyloxetane-3-yl) methyl acrylate (structure shown below), trade name OXE-10, manufactured by Osaka Organic Chemical Industry Co., Ltd.

・ Hydroxy (meth) acrylate: 4-hydroxybutyl acrylate (the following structure), trade name 4HBA, manufactured by Nippon Kasei Co., Ltd.

・ (Meth) acrylic compound C1: Aronix M-211B (bisphenol A ethyleneoxy-modified diacrylate, manufactured by Toagosei Co., Ltd.) (hereinafter structure)

In the formula, m≈2 and n≈2.
・ (Meth) acrylic compound C2: aromatic urethane acrylate, trifunctional, EBECRYL204, manufactured by Daicel Ornex ・ (meth) acrylic compound C3: isobornyl acrylate ・ (meth) acrylic compound C4: phenoxyethyl acrylate ・ radical generator D1: Irgacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF)
・ Thermal cation generator E1: Sun-Aid SI-60L, manufactured by Sanshin Chemical Industry Co., Ltd., can be heated at low temperature. ・ Curing catalyst F1: Orgatechs ZC-150 (zirconium tetraacetylacetonate, manufactured by Matsumoto Fine Chemical Co., Ltd.)

As shown in Table 2, Comparative Examples 1 and 2 not containing the specific (meth) acrylic compound (B) had low thermosetting properties.
The comparative example 3 which does not contain a specific (meth) acrylic compound (B) but contains hydroxy (meth) acrylate instead has low thermosetting, and low initial shear strength after curing by irradiation with active energy rays and heating. Adhesiveness was poor.

On the other hand, Examples 1-10 were excellent in the predetermined effect.
When Examples 3 and 4 are compared with Examples 1 and 2, the molar ratio of the reactive group / epoxy group in preparing the compound (A) is larger than 0.5. As compared with Examples 1 and 2 in which is 0.5 or less, the initial shear strength was high and the adhesion was excellent, and the shear strength after wet heat deterioration was high and the heat and moisture resistance was excellent.
When Examples 1 and 2 are compared, Example 1 in which the epoxy resin in preparing Compound (A) is bisphenol A type has an initial shear strength higher than that in Example 2 in which the epoxy resin is bisphenol F type. Highly superior in adhesiveness, high in shear strength after wet heat deterioration and excellent in heat and moisture resistance. Similar results were obtained by comparing Examples 3 and 4.
When Example 3 is compared with Example 8, Example 3 in which the (meth) acrylic compound (B) has an epoxy skeleton is earlier than Example 8 in which the (meth) acrylic compound (B) has an oxetane skeleton. High shear strength and excellent adhesiveness, high shear strength after wet heat degradation and excellent wet heat resistance.
Comparing Example 3 and Example 9, Example 3 further containing (meth) acrylic compound (C) has higher initial shear strength and better adhesion than Example 9, and shear after wet heat degradation. High strength and excellent heat and humidity resistance.
When Example 3, 5, 7 and Example 6 are compared, Example 3, 5, 7 in which (meth) acrylic compound (C) further has an aromatic hydrocarbon group is (meth) acrylic compound (C). Compared to Example 6 having an aliphatic hydrocarbon group, the initial shear strength was high and the adhesiveness was excellent, and the shear strength after wet heat deterioration was high and the heat and moisture resistance was excellent.
Comparing Example 3 and Example 10, Example 10 further containing a curing catalyst had higher initial shear strength and superior adhesiveness than Example 3.

DESCRIPTION OF SYMBOLS 10 Laminated body 12 Base material 14 Composition 16, 18 Member 20 Transparent member 22 Ultraviolet rays 24, 26, 28 Composition 30 Heat 40 Optical waveguide device 41 Optical fiber 42 Fiber array 43 Optical waveguide 44 Adhesive layer

Claims (10)

A compound (A) having an aromatic ring and a reactive silicon-containing group;
(Meth) acrylic compound (B) having a cationic polymerizable functional group and a (meth) acryloyloxy group;
A radical generator,
An adhesive composition for optical communication, comprising at least a cation generator that generates cations by heat.   The adhesive composition for optical communication according to claim 1, wherein the (meth) acrylic compound (B) further has a hydrocarbon group having 10 or less carbon atoms.   The adhesive composition for optical communication according to claim 1 or 2, wherein the compound (A) further has an ion polymerizable functional group.   The compound (A) is a compound obtained by reacting an ion polymerizable functional group-containing compound with a compound having a reactive group that reacts with the ion polymerizable functional group. Item 2. The adhesive composition for optical communication according to item 1. For the total content of the compound (A), the (meth) acrylic compound (B), the radical generator and the cation generator,
The content of the compound (A) is 30 to 50% by mass,
Content of the said (meth) acryl compound (B) is 10-60 mass%,
The content of the radical generator is 1 to 10% by mass,
The adhesive composition for optical communication according to any one of claims 1 to 4, wherein a content of the cation generator is 0.1 to 5% by mass.   The adhesive for optical communication according to any one of claims 1 to 5, further comprising a (meth) acryl compound (C) having no (meth) acryloyloxy group and having no cationic polymerizable functional group. Composition.   The adhesive composition for optical communication according to claim 6, wherein the (meth) acrylic compound (C) further has an aromatic hydrocarbon group.   The adhesive composition for optical communication according to claim 6 or 7, wherein the number of (meth) acryloyloxy groups contained in one molecule of the (meth) acrylic compound (C) is 1 to 3. For the total content of the compound (A), the (meth) acrylic compound (B), the (meth) acrylic compound (C), the radical generator and the cation generator,
The content of the compound (A) is 30 to 50% by mass,
Content of the said (meth) acryl compound (B) is 10-40 mass%,
Content of the said (meth) acryl compound (C) is 10-40 mass%,
The content of the radical generator is 1 to 10% by mass,
The adhesive composition for optical communication according to any one of claims 6 to 8, wherein a content of the cation generator is 0.1 to 5% by mass.   The adhesive composition for optical communication according to any one of claims 1 to 9, wherein the radical generator is a photoradical generator.