JP2007191667A - Adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-curable adhesive composition excellent in adhesivity and wet heat resistance. <P>SOLUTION: This adhesive composition comprises an epoxysilane obtained by reacting an epoxy resin with an imino group-containing silane coupling agent and an imidazole compound expressed by formula (I), wherein R<SP>1</SP>represents a chain hydrocarbon group or an alicyclic hydrocarbon group, where the chain hydrocarbon group and the alicyclic group may have at least one kind selected from the group consisting of an oxygen atom, a nitrogen atom and a hydrolyzable silicon-containing group; R<SP>2</SP>and R<SP>3</SP>represent each independently at least one kind selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an adhesive composition.

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. As for optical materials used in this optical communication system and bonding technology used for assembling optical elements, it is currently the mainstream to connect optical fibers using connectors, but the optical fiber is fixed to the ferrule in this connector. Therefore, high adhesive strength and reliability are required for the adhesive composition used for the purpose. In particular, when the optical fiber and the connector are joined via an adhesive, the optical fibers are always pressed against each other by a spring, and shear stress is always applied to the adhesive between the optical fiber and the ferrule. In some cases, the optical fiber is pulled in the long axis direction of the ferrule and a large load is applied. Therefore, this adhesive requires a high shear strength.
In addition, since the optical fiber may be installed outdoors or in an attic, it is required to have a characteristic capable of maintaining a sufficient adhesive force even in a severe environment such as high temperature and high humidity.

  Conventionally, quartz and glass have been used as optical fiber materials. However, plastic optical fibers (POFs) that are inexpensive, easy to process, resistant to bending, and very difficult to break have been developed. It has been put to practical use in short-distance communication applications such as digital home appliances, and the adhesive composition for optical fibers is required to have adhesiveness not only for glass but also for plastic (mainly acrylic plastic).

Conventionally, epoxy adhesives and the like have been used as adhesive compositions for optical fibers. However, recent studies indicate that epoxy adhesives have problems with durability. In addition, since curing of the epoxy adhesive requires heating at about 110 ° C., there is a problem that it cannot be easily applied at the site where the connection is actually made, and there is a rash when using the epoxy adhesive. Health damage such as this may occur.
Moreover, as a composition containing an epoxy resin, the thing of patent document 1 is mentioned, for example. Patent Document 1 discloses that an epoxy compound having two or more epoxy groups in a molecule, a compound having one or more alkoxysilyl groups and one or more groups capable of reacting with one or more epoxy groups in the molecule, and Accordingly, a modified epoxy resin obtained by adding a carboxylic acid and a resin composition comprising an alkoxysilane compound having a specific structure are described.

  On the other hand, Patent Document 2 describes an adhesive composition mainly composed of polysiloxane which is excellent in heat resistance, reduces the generation of bubbles during curing, and does not cause defects such as cloudiness due to bubbles. ing.

JP 2000-119488 A JP 2002-173661 A

However, the present inventor has found that the adhesive strength of the resin composition described in Patent Document 1 is lowered when placed in a high humidity environment for a long time.
In addition, since the adhesive composition described in Patent Document 2 contains polysiloxane as a main component, when it is placed in a high humidity environment for a long time, moisture may permeate and adhesive strength may be reduced. I found.

  Therefore, an object of the present invention is to provide an adhesive composition that can be moisture-cured and has excellent adhesiveness and heat-and-moisture resistance.

  As a result of intensive studies, the present inventors have found that a composition containing a compound having a specific structure obtained by reacting an epoxy resin with an imino group-containing silane coupling agent and an imidazole compound having a specific structure is capable of moisture curing. The present invention was completed by discovering that it is possible to obtain an adhesive composition excellent in adhesiveness and heat-and-moisture resistance.

That is, the present invention provides the following (1) to (5).
(1) An adhesive composition containing an epoxy silane obtained by reacting an epoxy resin with an imino group-containing silane coupling agent and an imidazole compound represented by the following formula (I) (hereinafter referred to as “the first of the present invention”). "Adhesive composition of one embodiment").

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)
(2) Further, the epoxy compound and the imino group-containing silane coupling agent are reacted with each other, and the epoxy compound of the epoxy compound contains a silane compound in which all of the epoxy groups are reacted with the imino group-containing silane coupling agent ( The adhesive composition as described in 1).
(3) The adhesive composition according to (1) or (2), further comprising an epoxy compound.
(4) an epoxy compound;
A silane compound obtained by reacting an epoxy compound with an imino group-containing silane coupling agent, wherein all epoxy groups of the epoxy compound are reacted with the imino group-containing silane coupling agent;
An adhesive composition containing an imidazole compound represented by the following formula (I) (hereinafter referred to as “the adhesive composition of the second aspect of the present invention”).

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)
(5) Adhesive composition containing an epoxy resin, an imino group-containing silane coupling agent, and an imidazole compound represented by the following formula (I) (hereinafter referred to as “adhesive composition according to the third aspect of the present invention”) Called "things").

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)

  The adhesive composition of the present invention can be cured by moisture and is excellent in adhesiveness and heat-and-moisture resistance.

Hereinafter, the present invention will be described in more detail.
The adhesive composition according to the first aspect of the present invention comprises:
It contains an epoxy silane obtained by reacting an epoxy resin with an imino group-containing silane coupling agent and an imidazole compound represented by the following formula (I).

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)

The epoxy silane will be described below.
The epoxy silane contained in the adhesive composition of the first aspect of the present invention is obtained by reacting an epoxy resin with an imino group-containing silane coupling agent.

The epoxy resin used in the production of epoxy silane is not particularly limited as long as it has two or more epoxy groups. Specifically, for example, bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, pyrocatechol, resorcinol, cresol novolac, tetrabromobisphenol A, trihydroxybiphenyl, bisresorcinol, bisphenol hexafluoroacetone Glycidyl ether type obtained by reaction of polychlorophenol such as tetramethylbisphenol F, bixylenol, dihydroxynaphthalene and epichlorohydrin; glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, polyethylene glycol, Aliphatic polyhydric alcohols such as polypropylene glycol and epichlorohydrin Polyglycidyl ether type obtained by the reaction of glycidyl ether ester type obtained by the reaction of hydroxycarboxylic acid such as p-oxybenzoic acid and β-oxynaphthoic acid and epichlorohydrin; phthalic acid, methylphthalic acid, isophthalic acid, terephthalic acid , Tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid, trimellitic acid, polyglycidyl ester type derived from polycarboxylic acid such as polymerized fatty acid; aminophenol, aminoalkylphenol Glycidylaminoglycidyl ether type derived from glycidylaminoglycidyl ester type derived from aminobenzoic acid; aniline, toluidine, tribromoaniline, xylylenediamine Glycidylamine type derived from amine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, etc .; epoxidized polyolefin, glycidylhydantoin, glycidylalkylhydantoin, triglycidylcyanurate Etc.
An epoxy resin can be used individually or in combination of 2 types or more, respectively.

  Especially, it is preferable that an epoxy resin has at least one aromatic ring from the point which is excellent in the mechanical strength and heat-and-moisture resistance of hardened | cured material. In particular, bisphenol A-type and bisphenol F-type epoxy compounds are preferable because they are easily available and have a good balance of properties (performance) of the cured product.

  In the present specification, the heat and humidity resistance means a property that can maintain the adhesiveness even when left in a high temperature or high humidity or high temperature and high humidity environment for a long time.

  The epoxy resin preferably has an epoxy equivalent of 50 to 500 in terms of good workability due to low viscosity and good heat resistance of the cured product, and more preferably 100 to 400. .

  The epoxy resin is not particularly limited for its production. For example, a conventionally well-known method is mentioned. Moreover, a commercial item can be used.

The imino group-containing silane coupling agent will be described below.
The imino group-containing silane coupling agent used in the production of epoxy silane is not particularly limited as long as it is a compound having an imino group and a reactive silicon-containing group.

The reactive silicon-containing group has 1 to 3 reactive groups bonded to a silicon atom, and in the presence of moisture or a crosslinking agent, the reaction is caused by using a catalyst or the like as necessary to crosslink. A silicon-containing group. Specific examples include silicon halide-containing groups, silicon hydride-containing groups, and hydrolyzable silicon-containing groups.
The reactive silicon-containing groups can be used alone or in combination of two or more.
Among these, a hydrolyzable silicon-containing group is preferable from the viewpoint of obtaining a composition that is excellent in storage stability and can be moisture-cured.

  The silicon halide-containing group is not particularly limited as long as it is a group having 1 to 3 halogen groups bonded to a silicon atom. Examples thereof include a chlorodimethylsilyl group, a dichloromethylsilyl group, and a trichlorosilyl group.

  The silicon hydride-containing group is not particularly limited as long as it is a group having 1 to 3 hydrogen atoms bonded to a silicon atom. Examples thereof include a hydrodimethylsilyl group, a dihydromethylsilyl group, and a trihydrosilyl group.

  The silicon halide-containing group can be crosslinked, for example, by causing a dehydrohalogenation reaction with the silicon hydride-containing group to form a bond. In addition, the silicon halide-containing group can be cross-linked by causing a metathesis reaction with a Grignard reagent to cause a dehalogenating metal reaction to form a silicon-carbon bond. In addition, when an alkali metal or magnesium is used as the silicon halide-containing group, a reductive silylation reaction is caused with an aromatic hydrocarbon, a conjugated diene, an aromatic aldehyde, a ketone, a carboxylic acid, an ester, or an imine to form a silicon-carbon. Bonds can be formed and crosslinked.

  The silicon hydride-containing group can be crosslinked, for example, by causing a dehydrohalogenation reaction with the silicon halide-containing group to form a bond. In addition, the silicon hydride-containing group can be crosslinked by causing a hydrosilylation reaction with a compound having an unsaturated carbon bond to form a silicon-carbon bond.

  The hydrolyzable silicon-containing group has 1 to 3 hydroxy groups and / or hydrolyzable groups bonded to a silicon atom, and in the presence of moisture or a crosslinking agent, a catalyst or the like is used as necessary. It is a silicon-containing group that can be crosslinked by causing a condensation reaction to form a siloxane bond. Examples thereof include an alkoxysilyl group, an alkenyloxysilyl group, an acyloxysilyl group, an aminosilyl group, an aminooxysilyl group, an oximesilyl group, and an amidosilyl group. Specific examples include groups represented by the following formula.

The hydrolyzable silicon-containing group is preferably an alkoxysilyl group from the viewpoint of easy handling.
The alkoxy group bonded to the silicon atom of the alkoxysilyl group is not particularly limited. A methoxy group, an ethoxy group, or a propoxy group is preferable because the raw material is easily available.
The group other than the alkoxy group bonded to the silicon atom of the alkoxysilyl group is not particularly limited. Examples thereof include a hydrogen atom; an alkyl group, an alkenyl group, or an arylalkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a propyl group, and an isopropyl group.
Examples of the alkoxysilyl group include a trimethoxysilyl group and a triethoxysilyl group.

  Examples of the imino group-containing silane coupling agent include a compound represented by the following formula (1) and a compound represented by the formula (2).

The compound represented by Formula (1) is demonstrated below.
In formula (1), R ⁹ is an alkylene group having 1 to 12 carbon atoms which may be branched, and R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 8 carbon atoms which may be branched. Yes, n is an integer of 0-2.

  Examples of the alkylene group having 1 to 12 carbon atoms which may be branched include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a 2-methyl-1,3-trimethylene group (isobutylene group), and a pentamethylene group. , Hexamethylene group, octamethylene group, decamethylene group, dodecamethylene group, and 3,3-dimethylbutylene group. A trimethylene group, a 2-methyl-1,3-trimethylene group, and a 3,3-dimethylbutylene group (3,3-dimethyl-1,4-butylene group) are preferable because they are easily available and have excellent adhesion.

Examples of the alkyl group having 1 to 8 carbon atoms which may be branched include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n -Pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, n-hexyl group, n-heptyl group, n-octyl group . These groups can contain double or triple bonds. Of these, a methyl group and an ethyl group are preferable. R ¹⁰ and R ¹¹ may be the same or different.
n is preferably 0 or 1.

  Examples of the compound represented by the formula (1) include N, N-bis [(3-trimethoxysilyl) propyl] amine, N, N-bis [(3-triethoxysilyl) propyl] amine, N, N-bis [(3-tripropoxysilyl) propyl] amine (made by Toray Dow Corning) is mentioned.

The compound represented by Formula (2) is demonstrated below.
Wherein (2), R ¹⁰ and R ¹¹ has the same meaning as R ¹⁰ and R ¹¹ of formula (1), R ¹² has the same meaning as R ⁹ of formula (1), R ¹³ is 1 to carbon atoms 8 is an optionally branched alkyl group or aromatic hydrocarbon group, and n is an integer of 0-2.

R ¹² is an alkylene group having 1 to 6 carbon atoms, such as a methylene group, a trimethylene group, or a 3,3-dimethylbutylene group (3,3-dimethyl-1,4-butylene group). Is preferred.

In R ¹³ , an alkyl group having 1 to 8 carbon atoms which may be branched has the same meaning as R ^{10 in} formula (1). Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a benzyl group, a styryl group, a tolyl group, a xylyl group, and a hydroxyphenyl group. Of these, a phenyl group and an optionally branched alkyl group having 2 to 4 carbon atoms (ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group) are preferable.
n is preferably 0 or 1.

Examples of the compound represented by the formula (2) include N-methyl-γ-aminopropyltrimethoxysilane, N-methyl-γ-aminopropyltriethoxysilane, N-ethyl-γ-aminopropyltrimethoxysilane, N-ethyl-γ-aminopropyltriethoxysilane, N-ethylaminoisobutyltrimethoxysilane, N- (n-butyl) -γ-aminopropyltrimethoxysilane, N- (n-butyl) -γ-aminopropyltri Ethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, N-phenylaminomethyldimethoxymethylsilane, N-phenyl-γ-aminopropyltrimethoxy Examples include silane.
Of these, N-ethylaminoisobutyltrimethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane are preferable from the viewpoint of excellent moisture curing, adhesiveness, and heat-and-moisture resistance.

Moreover, a commercial item can be used as an imino group containing silane coupling agent. Examples of commercially available products include Alink15, Y-9669, Al170 manufactured by Toray Dow Corning, Inc .; XL-924, XL-926, XL- manufactured by Asahi Kasei Wacker Silicone, Inc.
972, XL-973.
The imino group-containing silane coupling agents can be used alone or in combination of two or more.

  The amount of the imino group-containing silane coupling agent used is superior in moisture curing, adhesion, and heat-and-moisture resistance, and the ratio of all epoxy groups of the epoxy resin to the imino group of the imino group-containing silane coupling agent (epoxy group / imino Group) is preferably 10/1 to 1/1, more preferably 5/1 to 1/1.

  Epoxysilane is not particularly limited for its production. For example, it can be performed according to a conventionally known method. Specifically, for example, a method in which an epoxy resin and an imino group-containing silane coupling agent are mixed preferably in an amount ratio that gives an addition rate described later and reacted at room temperature to 150 ° C. can be mentioned. The reaction temperature is preferably 80 to 120 ° C. from the viewpoint of the reaction rate.

  In the reaction, it is preferable that the addition ratio of the imino group-containing silane coupling agent with respect to all epoxy groups in the epoxy resin is 10 mol% or more and less than 100 mol% from the viewpoint of being excellent in moisture curing, adhesion, and heat and moisture resistance. . Since such an effect is further excellent, the addition rate is more preferably 20 mol% or more and less than 100 mol%.

  The resulting epoxy silane is a compound having an epoxy group and a hydroxy group derived from an epoxy group, a reactive silicon-containing group derived from an imino group-containing silane coupling agent, and a tertiary nitrogen atom.

  As an epoxy silane, for example, an imino group-containing silane coupling agent having one imino group per molecule is used for an aromatic epoxy resin having two epoxy groups and at least one aromatic ring per molecule. What was obtained by carrying out 1 equivalent reaction is mentioned. Specifically, for example, an epoxy silane represented by the formula (3) obtained by reacting 1 equivalent of N-ethylaminoisobutyltrimethoxysilane with bisphenol A glycidyl ether, N- with respect to bisphenol F glycidyl ether. An epoxy silane represented by the formula (4) obtained by reacting 1 equivalent of ethylaminoisobutyltrimethoxysilane is exemplified.

From the viewpoint that the epoxy silane has a number average molecular weight per reactive silicon-containing group, the crosslink density of the cured product is increased, mechanical strength such as shear strength is further improved, and adhesion and wet heat resistance are superior. It is preferably 1000 or less, more preferably 900 or less, and even more preferably 800 or less.
In addition, the number average molecular weight per reactive silicon-containing group of epoxysilane is preferably 50 or more, more preferably 70 or more, from the viewpoint that the crosslinking density can be prevented from becoming too high.

The imidazole compound will be described below.
The imidazole compound contained in the adhesive composition of the first aspect of the present invention is a compound represented by the formula (I).

In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are composed of an oxygen atom, a nitrogen atom and a hydrolyzable silicon-containing group. It may have at least one selected from the group, and R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.

R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are selected from the group consisting of an oxygen atom, a nitrogen atom and a hydrolyzable silicon-containing group. It can have at least one selected.

  The chain hydrocarbon group is not particularly limited. For example, the thing of 1-20 carbon atoms is mentioned. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, n-hexyl group, n-heptyl group, n-octyl group, undecyl group, heptadecyl group.

  The alicyclic hydrocarbon group is not particularly limited. For example, the thing of 3-10 carbon atoms is mentioned. Specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a methylcyclohexyl group, an ethylcyclohexyl group, a methylcycloheptyl group, and an ethylcycloheptyl group.

  The chain hydrocarbon group and the alicyclic hydrocarbon group can have at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. Moreover, the chain hydrocarbon group and the alicyclic hydrocarbon group may be branched.

  The hydrolyzable silicon-containing group has the same meaning as described above. One or more hydrolyzable silicon-containing groups can be bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group. From the viewpoint of being excellent in moisture curing, adhesiveness, and heat-and-moisture resistance, it is preferable that two or more hydrolyzable silicon-containing groups are bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group.

R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group, and a vinyl group.
The alkyl group is not particularly limited. The alkyl group may be branched. For example, a C1-C5 thing is mentioned. Specifically, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert- A pentyl group is mentioned.

  Examples of the imidazole compound include a compound represented by the following formula (II) and an imidazole compound described in JP-A-5-186479.

In the formula, R ⁴ represents a divalent to tetravalent hydrocarbon group or a divalent to hexavalent alicyclic hydrocarbon group, and the divalent to tetravalent hydrocarbon group and the divalent to hexavalent alicyclic ring. The formula hydrocarbon group may have at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group, and R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, , At least one selected from the group consisting of an alkenyl group and an arylalkyl group, R ⁷ and R ⁸ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group, m is an integer of 1 to 5, and n is an integer of 1 to 3.

R ⁴ represents a divalent to tetravalent hydrocarbon group or a divalent to hexavalent alicyclic hydrocarbon group, and the divalent to tetravalent hydrocarbon group and the divalent to hexavalent alicyclic carbon group. The hydrogen group can have at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group.

Examples of the divalent to tetravalent chain hydrocarbon group and the divalent to hexavalent alicyclic hydrocarbon group include, for example, removing 1 to 5 hydrogen atoms from the above chain hydrocarbon group and alicyclic hydrocarbon group. Groups.
The hydrolyzable silicon-containing group is the same as described above.

R ⁵ and R ⁶ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an arylalkyl group.
The alkyl group, alkenyl group and arylalkyl group are not particularly limited. Alkyl, alkenyl and arylalkyl groups can be branched. One preferred embodiment is an alkyl group having 1 to 5 carbon atoms. Examples thereof include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

R ⁷ and R ⁸ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group, and a vinyl group. Alkyl group has the same meaning as R ^2, R ^3.

The imidazole compound preferably has a hydrolyzable silicon-containing group from the viewpoint of being excellent in moisture curing, adhesiveness, and heat-and-moisture resistance.
In addition, the imidazole compound does not have a group that promotes the curing reaction of the epoxy group (for example, a hydroxy group), but the viewpoint that the epoxy group in the composition does not react with active hydrogen and is excellent in storage stability. To preferred.

  Examples of the imidazole compound represented by the formula (II) include a compound represented by the following formula (III).

The imidazole compound is not particularly limited for its production. For example, a conventionally well-known method is mentioned.
Moreover, a commercial item can be used for the imidazole compound. As a commercial item of an imidazole compound, Nikko Materials Co., Ltd. IM-1000 is mentioned, for example.

  The content of the imidazole compound is preferably 0.01 to 50 parts by mass, preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the epoxy silane, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and humidity resistance. It is more preferable that

  The adhesive composition according to the first aspect of the present invention further comprises a reaction of an epoxy compound with an imino group-containing silane coupling agent, wherein all of the epoxy groups of the epoxy compound are the imino group-containing silane coupling agent. A reacting silane compound can be contained.

The silane compound is not particularly limited as long as all the epoxy groups of the epoxy compound obtained by reacting the epoxy compound with the imino group-containing silane coupling agent are reacted with the imino group-containing silane coupling agent.
The epoxy compound used in the production of the silane compound is not particularly limited as long as it has one or more epoxy groups. Examples of the epoxy compound include a monoepoxy compound and an epoxy resin.

The monoepoxy compound is not particularly limited as long as it is a compound having one epoxy group.
Examples of the monoepoxy compound include butyl glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, benzoic acid glycidyl ester, and styrene oxide.
The epoxy resin is the same as described above.
The imino group-containing silane coupling agent is the same as described above.

  From the standpoint that the amount of imino group-containing silane coupling agent used is superior in moisture curing, adhesion, and heat-and-moisture resistance, the ratio of all epoxy groups in the epoxy compound to imino groups in the imino group-containing silane coupling agent (epoxy group / imino Group) is preferably 1/1 to 1/10, more preferably 1/1 to 1/5.

  The production of the silane compound is not particularly limited. For example, it can be performed according to a conventionally known method. Specifically, for example, an epoxy compound and an imino group-containing silane coupling agent are mixed in an amount ratio that gives an addition rate described later, and are reacted at room temperature to 150 ° C., preferably from 80 to 120 ° C. from the viewpoint of reaction rate. A method is mentioned.

  In the production of the silane compound, the addition rate of the imino group-containing silane coupling agent with respect to all epoxy groups in the epoxy compound is 100 mol% from the viewpoint of being excellent in moisture curing, adhesiveness, and heat-and-moisture resistance.

  The resulting silane compound is a compound having a hydroxy group derived from an epoxy group, a reactive silicon-containing group derived from an imino group-containing silane coupling agent, and a tertiary nitrogen atom.

  Examples of the silane compound include those obtained by reacting 2 equivalents of an iminosilane having one imino group in one molecule with an aromatic epoxy compound having two epoxy groups in one molecule. Specifically, for example, a silane compound represented by the following formula (5) obtained by reacting 2 equivalents of N-ethylaminoisobutyltrimethoxysilane with bisphenol A glycidyl ether, N with respect to bisphenol F glycidyl ether. Examples include silane compounds represented by the following formula (6) obtained by reacting 2 equivalents of ethylaminoisobutyltrimethoxysilane.

From the viewpoint that the silane compound has a number average molecular weight per reactive silicon-containing group, the crosslink density of the cured product is increased, mechanical strength such as shear strength is further improved, and adhesion and moisture heat resistance are excellent. It is preferably 1000 or less, more preferably 900 or less, and even more preferably 800 or less.
In addition, the number average molecular weight per reactive silicon-containing group of the silane compound is preferably 50 or more, and more preferably 70 or more, from the viewpoint that the crosslinking density can be prevented from becoming too high.

  The content of the silane compound is preferably 1 to 1000 parts by mass, and preferably 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy silane, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. More preferred.

  The adhesive composition according to the first aspect of the present invention may further contain an epoxy compound from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and humidity resistance.

The epoxy compound is the same as described above.
The content of the epoxy compound is preferably 1 to 1000 parts by mass, and preferably 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy silane, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. More preferred.

  When the epoxy compound is contained, the content of the imidazole compound is 0.01 to 50 parts by mass with respect to 100 parts by mass of the total amount of the epoxy silane and the epoxy compound from the viewpoint of being excellent in moisture curing, adhesion, and heat and moisture resistance. It is preferable that it is 0.1-30 mass parts.

  The adhesive composition according to the first aspect of the present invention is the epoxy compound obtained by further reacting an epoxy compound with an imino group-containing silane coupling agent from the viewpoint of being superior in moisture curing, adhesiveness, and heat-and-moisture resistance. A silane compound in which all of the epoxy groups are reacted with the imino group-containing silane coupling agent and an epoxy compound can be contained.

The silane compound is the same as described above.
In such a case, the content of the silane compound is preferably 1 to 1000 parts by mass, and 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy silane, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. It is more preferable that

The epoxy compound is the same as described above.
In such a case, the content of the epoxy compound is preferably 1 to 1000 parts by mass, and 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy silane, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. It is more preferable that

The inventor of the present invention has an epoxy silane obtained by reacting an epoxy resin with an amino group-containing silane coupling agent, and has a hydroxy group derived from the epoxy group and a secondary nitrogen atom in the vicinity thereof. It has been found that the obstacles are relatively small and the hydroxy group reacts with the epoxy group, reducing the storage stability of the composition.
On the other hand, the epoxy silane contained in the adhesive composition according to the first aspect of the present invention is obtained by reacting an epoxy resin and an imino group-containing silane coupling agent. It has a group and a tertiary nitrogen atom in the vicinity thereof. That is, the steric hindrance near the hydroxy group is high, and the hydroxy group hardly reacts with the epoxy group.
Therefore, the adhesive composition of the first aspect of the present invention is excellent in storage stability.
In addition, since a hydrogen bond is formed between the hydroxy group of the epoxy silane and another hydroxy group or / and a silanol group not involved in crosslinking, mechanical strength such as shear strength is further improved, and adhesion and Excellent moisture and heat resistance.

In addition, imidazole compounds that have been used as anionic polymerization catalysts for epoxy resins in the past have a high activity because they have a hydrogen atom at the first nitrogen atom of the imidazole ring. The present inventors have found that the composition is inferior in storage stability because the group is anionically polymerized.
On the other hand, the imidazole compound contained in the adhesive composition of the first aspect of the present invention does not have a hydrogen atom at the first nitrogen atom of the imidazole ring. Therefore, a compound having an epoxy group hardly reacts with such an imidazole compound at room temperature, and is excellent in the storage stability of the composition.
The imidazole compound contained in the adhesive composition of the first aspect of the present invention can sufficiently function as an anionic polymerization catalyst for epoxy groups by heating.

Next, the adhesive composition according to the second aspect of the present invention will be described.
The adhesive composition of the second aspect of the present invention is:
An epoxy compound,
A silane compound obtained by reacting an epoxy compound with an imino group-containing silane coupling agent, wherein all epoxy groups of the epoxy compound are reacted with the imino group-containing silane coupling agent;
It contains an imidazole compound represented by the following formula (I).

In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are composed of an oxygen atom, a nitrogen atom and a hydrolyzable silicon-containing group. It may have at least one selected from the group, and R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.

An epoxy compound and a silane compound are synonymous with the adhesive composition of the 1st aspect of this invention.
The content of the silane compound is preferably 1 to 1000 parts by mass, and preferably 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy compound, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. More preferred.

The imidazole compound is synonymous with the adhesive composition of the first aspect of the present invention.
The content of the imidazole compound is preferably 0.01 to 50 parts by mass, preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the epoxy compound, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. It is more preferable that

Next, the adhesive composition according to the third aspect of the present invention will be described.
The adhesive composition of the third aspect of the present invention is
It contains an epoxy resin, an imino group-containing silane coupling agent, and an imidazole compound represented by the following formula (I).

In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are composed of an oxygen atom, a nitrogen atom and a hydrolyzable silicon-containing group. It may have at least one selected from the group, and R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.

The epoxy resin and the imino group-containing silane coupling agent are synonymous with the adhesive composition of the first aspect of the present invention.
The content of the imino group-containing silane coupling agent is preferably 1 to 1000 parts by mass, and 10 to 800 parts by mass with respect to 100 parts by mass of the epoxy resin, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. More preferably, it is part.

The imidazole compound is synonymous with the adhesive composition of the first aspect of the present invention.
The content of the imidazole compound is preferably 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. It is more preferable that

The adhesive composition according to the third aspect of the present invention can further contain a monoepoxy compound.
The monoepoxy compound is synonymous with the adhesive composition of the first aspect of the present invention.
The content of the monoepoxy compound is preferably from 0.01 to 100 parts by weight, preferably from 0.1 to 50 parts by weight, based on 100 parts by weight of the epoxy resin, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. More preferably, it is part.

  When the adhesive composition of the third aspect of the present invention contains a monoepoxy compound, the content of the imidazole compound is the sum of the epoxy resin and the monoepoxy compound from the viewpoint that it is more excellent in moisture curing, adhesiveness, and heat and humidity resistance. It is preferable that it is 0.01-50 mass parts with respect to 100 mass parts of quantity, and it is more preferable that it is 0.1-30 mass parts.

In the adhesive composition of the third aspect of the present invention, the epoxy resin and the imino group-containing silane coupling agent gradually react immediately after being mixed to react the epoxy resin with the imino group-containing silane coupling agent. The epoxy silane obtained by the reaction and the epoxy resin and the imino group-containing silane coupling agent can be reacted to form a silane compound in which all epoxy groups of the epoxy resin are reacted with the imino group-containing silane coupling agent.
Epoxy silane and silane compound are synonymous with the adhesive composition of the first aspect of the present invention.

The adhesive composition of the first to third aspects of the present invention can further contain a silane coupling agent.
The silane coupling agent is not particularly limited. For example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxy Alkoxysilanes having methacrylic or acrylic groups such as silane, acryloxymethyltrimethoxysilane, acryloxymethyltriethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- Epoxy silanes such as glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane And the like.

  In the adhesive composition of the first aspect of the present invention, the content of the silane coupling agent is based on the total amount of the epoxy silane and the silane coupling agent from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. The content is preferably 5 to 99% by mass, more preferably 10 to 90% by mass, and still more preferably 20 to 80% by mass.

  In the adhesive composition according to the second aspect of the present invention, the content of the silane coupling agent is more excellent in moisture curing, adhesion, and heat and humidity resistance, with respect to the total amount of the epoxy compound and the silane coupling agent. The content is preferably 5 to 99% by mass, more preferably 10 to 90% by mass, and still more preferably 20 to 80% by mass.

  In the adhesive composition of the third aspect of the present invention, the content of the silane coupling agent is based on the total amount of the epoxy resin and the silane coupling agent from the viewpoint of being excellent in moisture curing, adhesiveness, and heat and moisture resistance. The content is preferably 5 to 99% by mass, more preferably 10 to 90% by mass, and still more preferably 20 to 80% by mass.

It is preferable that the adhesive composition of the first to third aspects of the present invention further contains a curing catalyst.
As the curing catalyst, those generally used for reactive silicon-containing group-containing compounds can be used. Specifically, for example, carboxylic acid metal salts such as zinc octoate, iron octoate, manganese octoate, tin octoate, zinc naphthenate, iron naphthenate, tin butanoate, tin caprylate, tin oleate; dibutyltin Diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin dioleate, dioctyltin dilaurate, diphenyltin diacetate, dibutyltin oxide, reaction product of dibutyltin oxide and phthalate, dibutyltin dimethoxide, dibutyltin (triethoxysiloxy), Organotin compounds such as dibutyltin silicate; tin chelate compounds such as dibutyltin diacetylacetonate; tetraethoxy titanium, tetrapropoxy titanium, tetrabutoxy titanium, tetra-2-ethylhex Titanic acid esters such as ruoxytitanium and tetraisopropenyloxytitanium; diisopropoxytitanium bis (acetylacetonate), diisopropoxytitanium bis (ethylacetoacetate), 1,3-propanedioxytitanium bis (acetylacetonate), 1,3 -Titanium chelate compounds such as propanedioxytitanium bis (ethyl acetoacetate) and titanium tris (acetylacetonate); Zirconium alkoxides such as tetraisopropoxyzirconium, tetrabutoxyzirconium and tributoxyzirconium stearate; Zirconium tetra (acetylacetonate) Zirconium chelate compounds such as triethoxyaluminum, tripropoxyaluminum, and tributoxyaluminum De; diisopropoxyaluminum (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum chelate compounds such as aluminum tris (ethylacetoacetate);

Primary amines such as butylamine, hexylamine, octylamine, dodecylamine, oleylamine, cyclohexylamine, benzylamine; secondary amines such as dibutylamine; diethylenetriamine, triethylenetetramine, guanidine, diphenylguanidine, xylylenediamine, etc. Polyamines; cyclic amines such as triethylenediamine, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo [5.4.0] -7-undecene; monoethanolamine, diethanolamine, triethanol Amino alcohol compounds such as amines; amine compounds such as aminophenol compounds such as 2,4,6-tris (dimethylaminomethyl) phenol and their carboxylates; Quaternary ammonium salts such as trimonium acetate; low molecular weight amide resin obtained from excess polyamine and polybasic acids; excess of the reaction product of a polyamine and an epoxy compound, and the like.
The curing catalysts can be used alone or in combination of two or more.

  Among these, metal compounds are preferable because they are less likely to volatilize during storage and operation, and among them, organotin compounds, tin chelate compounds, and titanate esters are preferable because excellent catalytic ability can be obtained with a small amount of compounding.

  In the adhesive composition of the first aspect of the present invention, the content of the curing catalyst can sufficiently exhibit the effect of the curing catalyst, there is no problem with compatibility with other components, and local heat generation during curing. From the viewpoint that no foaming occurs, the amount is preferably 1 to 50 parts by mass, more preferably 1 to 40 parts by mass, and still more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the epoxysilane.

  In the adhesive composition of the second aspect of the present invention, the content of the curing catalyst can sufficiently exhibit the action of the curing catalyst, there is no problem with compatibility with other components, and local heat generation during curing. From the viewpoint that no foaming occurs, the amount is preferably 1 to 50 parts by mass, more preferably 1 to 40 parts by mass, and still more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the silane compound.

  In the adhesive composition of the third aspect of the present invention, the content of the curing catalyst can sufficiently exhibit the action of the curing catalyst, there is no problem with compatibility with other components, and local heat generation during curing. Or 50 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the imino group-containing silane coupling agent. .

  The adhesive composition of the first to third aspects of the present invention, if necessary, within a range not impairing the object of the present invention, for example, a filler, a reaction retarding agent, an anti-aging agent, an antioxidant, Additives such as pigments (dyes), plasticizers, thixotropic agents, UV absorbers, flame retardants, solvents, surfactants (including leveling agents), dispersants, dehydrating agents, adhesion-imparting agents, and antistatic agents Can be contained.

Examples of the filler include organic or inorganic fillers having various shapes. Specifically, for example, fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide; calcium carbonate, magnesium carbonate, zinc carbonate; Waxite clay, kaolin clay, calcined clay; carbon black; these fatty acid treated products, resin acid treated products, urethane compound treated products, and fatty acid ester treated products.
The content of the filler is preferably 90% by mass or less in the entire composition in terms of physical properties of the cured product.

Examples of the reaction retardant include alcohol compounds.
Examples of the antiaging agent include hindered phenol compounds.
Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).

  Examples of the pigment include inorganic pigments such as titanium oxide, zinc oxide, ultramarine blue, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate, etc .; azo pigment, phthalocyanine pigment, quinacridone pigment, quinacridone quinone pigment , Dioxazine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanthrone pigment, flavanthrone pigment, perylene pigment, perinone pigment, diketopyrrolopyrrole pigment, quinonaphthalone pigment, anthraquinone pigment, thioindigo pigment, benzimidazolone pigment, isoindoline pigment And organic pigments such as carbon black.

  Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP); dioctyl adipate, isodecyl succinate; diethylene glycol dibenzoate, pentaerythritol ester; butyl oleate, methyl acetylricinoleate; tricresyl phosphate, phosphoric acid Trioctyl; propylene glycol adipate polyester, butylene glycol polyester adipate, and the like.

Examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.) and disparon (manufactured by Enomoto Kasei Co., Ltd.).
Examples of the adhesion imparting agent include terpene resin, phenol resin, terpene-phenol resin, rosin resin, and xylene resin.

Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.
Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

The adhesive composition of the first to third aspects of the present invention is basically capable of moisture curing. It can also be cured by heating.
When used as a moisture-curing type, workability is excellent because there is no need to heat.
On the other hand, when used as a thermosetting type, the curing time is short and the deep curability is excellent.
When using as a thermosetting type, it is preferable that heating temperature is 60-200 degreeC.
Therefore, a moisture-curing type or a heat-curing type can be appropriately selected and used according to the application or construction location.

Moreover, the adhesive composition of the 1st-3rd aspect of this invention can be used as a 1 liquid type or a 2 liquid type adhesive composition.
When used as a one-pack type, there is no need to mix the main agent and the curing agent in the field, resulting in excellent workability.
On the other hand, when used as a two-component type, the curing time is short and the deep curability is excellent.
Therefore, the one-component type or the two-component type can be appropriately selected according to the application and construction location.

When the adhesive composition of the first aspect of the present invention is used as a two-pack type, for example, a two-pack type adhesive composition comprising a main agent containing an epoxysilane and an imidazole compound and a curing agent can be obtained. .
When the adhesive composition according to the second aspect of the present invention is used as a two-pack type, for example, a two-pack type adhesive composition comprising a main agent containing an epoxy compound, a silane compound and an imidazole compound and a curing agent is used. be able to.
When the adhesive composition according to the third aspect of the present invention is used as a two-component adhesive, for example, a two-component adhesive comprising an epoxy resin, an imino group-containing silane coupling agent and a main component containing an imidazole compound, and a curing agent. It can be set as an agent composition.
In the adhesive composition of the first to third aspects of the present invention, the curing catalyst and the additive that are optionally added can be blended in one or both of the main agent side and the curing agent side.

Examples of the curing agent include water and other active hydrogen-containing compounds. Of these, water is preferable from the viewpoint of cost and ease of handling.
The amount of the curing agent used is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the silane component of each aspect, from the viewpoint of being excellent in moisture curing, adhesiveness, and heat-and-moisture resistance. More preferably, it is 10 parts by mass.

  The adhesive composition of the first to third aspects of the present invention is not particularly limited for its production, and for example, the above-described components and additives to be added as desired are preferably used under reduced pressure or in an inert atmosphere. Below, it can be obtained by sufficiently kneading and uniformly dispersing using a mixing device such as a ball mill.

  The adhesive composition according to the first to third aspects of the present invention can be moisture-cured, and is excellent in adhesiveness and heat-and-moisture resistance.

  As an adherend which can use the adhesive composition of the 1st-3rd aspect of this invention, the thing of a glass material, a plastic material, a metal, an organic inorganic composite material is mentioned, for example.

  The adhesive composition of the 1st-3rd aspect of this invention is not restrict | limited in particular about the use. For example, it can be used for bonding optical materials.

Examples of the optical material include an optical fiber, a lens, a filter, an optical waveguide, a diffraction grating, an optical active element, and a ferrule.
Examples of the optical fiber include a single mode optical fiber and a multimode optical fiber.
Examples of the lens include a refractive index distribution lens, a spherical lens, an aspheric lens, and a plano-convex lens.
Examples of the optical filter include a narrow band filter, a band pass filter, and a polarizing filter made of a dielectric multilayer film.
Examples of the optical waveguide include a single mode optical waveguide, a multimode optical waveguide, and those having a Bragg diffraction grating whose refractive index is periodically modulated in these optical waveguides.
Examples of ferrules include zirconium oxide ferrules and crystallized glass ferrules.

Examples of the material constituting the optical material include glass materials, plastic materials, metals, organic-inorganic composite materials, and the like.
That is, the adhesive composition of the first to third aspects of the present invention can be used for bonding glass optical fibers, plastic optical fibers, zirconia ferrules, crystallized glass ferrules, etc. Plastic optical fibers can be bonded together, or glass or plastic optical fibers and zirconia or crystallized glass ferrules can be bonded.

When assembling the optical material, after the adhesive composition according to the first to third aspects of the present invention is disposed between the first optical material (for example, optical fiber) and the second optical material (for example, ferrule). Can be cured to form a bond having the desired strength.
Moreover, you may form a primer layer in the surface of the adhesive body joined using the adhesive composition of the 1st-3rd aspect of this invention. As a primer, a conventionally well-known thing is mentioned, for example.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
1. Preparation of epoxy silane and silane compound 1-1. Preparation of epoxysilane (Synthesis Examples 1, 3)
Each component shown in Table 1 was mixed with the composition (parts by mass) shown in Table 1, and stirred at 120 ° C. for 8 hours in an inert gas atmosphere to obtain an epoxysilane. The obtained epoxy silanes are designated as epoxy silane 1 and epoxy silane 2. Epoxysilane 1 is a compound represented by the following formula (3), and epoxysilane 2 is a compound represented by the following formula (4).

  The silylation rate shown in Table 1 indicates the percentage (theoretical value) of the ratio of the number of reacted imino group-containing silane coupling agents to the total number of epoxy groups of the epoxy resin. For example, in Synthesis Example 1, since one imino group-containing silane coupling agent having one imino group is reacted with one epoxy resin having two epoxy groups, the silylation rate is 50%. Become.

1-2. Preparation of silane compound (Synthesis Examples 2, 4)
Each component shown in Table 1 was mixed with the composition (parts by mass) shown in Table 1, and stirred at 120 ° C. for 8 hours in an inert gas atmosphere to obtain a silane compound. The obtained silane compounds are referred to as silane compound 1 and silane compound 2. Silane compound 1 is a compound represented by the following formula (5), and silane compound 2 is a compound represented by the following formula (6). In the silane compound 1 and the silane compound 2, the epoxy groups of the raw material epoxy compound are all silylated, and the silylation rate is 100%.

Each component in Table 1 is as follows.
Epoxy resin 1 (bisphenol A glycidyl ether): Epototo YD-128, manufactured by Toto Kasei Co., Ltd. (the same applies hereinafter)
Epoxy resin 2 (bisphenol F glycidyl ether): Epototo YDF-170, manufactured by Toto Kasei Co., Ltd. (the same applies hereinafter)
-Imino group-containing silane coupling agent: Alink-15, manufactured by Toray Dow Corning, N-ethylaminoisobutyltrimethoxysilane (hereinafter the same).

2. Preparation of adhesive composition (Examples 1 to 8 and Comparative Examples 1 and 2)
Mix each component of Liquid A shown in Table 2 below with the composition (parts by mass) shown in Table 2, and thoroughly disperse using a stirrer, then add all components of Liquid B and disperse sufficiently. Thus, each composition was obtained.

3. Evaluation of Adhesive Composition Using each of the obtained compositions, adhesiveness and heat-and-moisture resistance were evaluated as follows. The results are shown in Table 2.

Two glass plates (length 30 mm × width 25 mm × thickness 5 mm) were prepared, and each one end 3 mm × width 25 mm was superimposed through the obtained adhesive compositions, and then at 130 ° C. A test specimen was prepared by heat curing for 3 hours. Using the prepared specimen, the shear strength (after heat curing) was measured according to JIS K6852-1994.
In addition, a test specimen prepared in the same manner as described above was left to deteriorate for 10 days in an environment of 80 ° C. and 95% RH. Using this test body, the shear strength (after the wet heat deterioration test) was measured in the same manner as described above.
In Example 8, the liquid A was mixed with the liquid B 1 hour after the preparation of the liquid A to obtain an adhesive composition.

The components shown in Table 2 are as follows.
・ Imidazole compound 1; Imidazole silane, manufactured by Nikko Materials Co., Ltd. ・ Silane coupling agent: A-187, manufactured by Toray Dow Corning, γ-glycidoxypropyltrimethoxysilane ・ Catalyst: TPT-100, Japan Soda Co., Ltd., tetrapropoxytitanium imidazole compound 2: 2E4MZ, Shikoku Kasei Co., Ltd., 2-ethyl-4-methylimidazole

  As is clear from the results in Table 2, the compositions (Examples 1 to 8) containing at least one of the compounds obtained in Synthesis Examples 1 to 4 do not contain the compounds obtained in Synthesis Examples 1 to 4. Compared with the composition (Comparative Example 1) and the composition (Comparative Example 2) containing an imidazole compound having active hydrogen, it had excellent adhesiveness. In particular, since the difference in shear strength after wet heat degradation was significant, it was proved that the compositions of Examples 1 to 8 were extremely excellent in wet heat resistance.

4). Adhesion of Optical Fiber and Ferrule FIG. 1 is a schematic longitudinal sectional view showing an example of a connection portion where an optical fiber and a ferrule are bonded using the adhesive composition of the present invention.
In FIG. 1, 1 is an optical fiber, 7 is a ferrule, and 8 is a plug.
Ferrule 7 is made of zirconia. The ferrule 7 and the plug 8 are connected and fixed in advance as shown in FIG.
The optical fiber 1 is made of glass and has a length of about 1 m. The optical fiber 1 has a polymer coating layer 4, a core portion 2, and a cladding portion 3. In the polymer coating layer 4, a portion (not shown) between the end of the optical fiber 1 and 2 cm in the longitudinal direction is removed from the optical fiber 1, and the adhesive composition of Example or Comparative Example is applied to this portion. Thus, the adhesive layer 6 is disposed. Next, the optical fiber 1 having the adhesive layer 6 is inserted into the cavity (not shown) of the ferrule 7 from the end (not shown) of the plug 8 and then heated to 130 ° C. and left to stand for 3 hours. The optical fiber 1 and the ferrule 7 were bonded through 6 to prepare a sample. Let the obtained sample be the sample after heat-hardening. Thereafter, the end face of the ferrule of the sample after heat curing is precisely polished.
The sample after heat curing was further left for 10 days in an environment of 80 ° C. and 95% RH. This is the sample after the wet heat degradation test.
Next, with respect to the sample after heat curing and the sample after the wet heat deterioration test, each ferrule 7 and the optical fiber 1 were grasped and lightly pulled.
As a result, among the samples that were bonded using the composition of the comparative example, the bonded portion of the heat-cured sample was not destroyed, but in the sample after the wet heat deterioration test, the bonded portion 6 and the optical fiber 1 Peeling occurred at the interface.
On the other hand, in the case of bonding using the adhesive composition of the example, the bonded portion of any sample was not destroyed. This is considered because the adhesive composition of an Example is excellent in adhesiveness and heat-and-moisture resistance.

FIG. 1 is a schematic longitudinal sectional view showing an example of a connection portion in which an optical fiber and a ferrule are bonded using the adhesive composition of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Core part 3 Clad part 4 Polymer coating layer 6 Adhesive layer 7 Ferrule 8 Plug

Claims (5)

An adhesive composition comprising an epoxy silane obtained by reacting an epoxy resin and an imino group-containing silane coupling agent, and an imidazole compound represented by the following formula (I).

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)   Furthermore, the epoxy compound and imino group containing silane coupling agent are made to react, The epoxy group of the said epoxy compound contains all the silane compounds which are reacting with the said imino group containing silane coupling agent. Adhesive composition.   Furthermore, the adhesive composition of Claim 1 or 2 containing an epoxy compound. An epoxy compound,
A silane compound obtained by reacting an epoxy compound with an imino group-containing silane coupling agent, wherein all epoxy groups of the epoxy compound are reacted with the imino group-containing silane coupling agent;
An adhesive composition containing an imidazole compound represented by the following formula (I).

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.) An adhesive composition containing an epoxy resin, an imino group-containing silane coupling agent, and an imidazole compound represented by the following formula (I).

(In the formula, R ¹ represents a chain hydrocarbon group or an alicyclic hydrocarbon group, and the chain hydrocarbon group and the alicyclic hydrocarbon group are derived from an oxygen atom, a nitrogen atom, and a hydrolyzable silicon-containing group. And at least one selected from the group consisting of R ² and R ³ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group and a vinyl group.)

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