JP2005281528A - Adhesive composition for optical material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for optical materials excellent in moist heat resistance, moisture-curable, and excellent in adhesive properties, particularly adhesive properties to glass and plastics, and to provide an adhesive composition for an optical material having the properties above and further giving a cured product of high transparency. <P>SOLUTION: The adhesive composition for optical materials comprises (A) 100 pts.mass of a polymer containing an alkyl acrylate monomer unit and/or an alkyl methacrylate monomer unit in the main chain and at least one hydrolyzable silicon-containing group in one molecule, (B) 1-150 pts.mass of a reaction product of an epoxy compound with an aminosilane, and (C) 1-50 pts.mass of a curing catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adhesive composition for optical materials. More specifically, the present invention relates to an adhesive composition for optical materials that is suitably used for connection between optical fibers or adhesion between an optical fiber and a ferrule.

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 the optical materials used in this optical communication system and the joining technique used for assembling the optical elements, it is currently the mainstream to connect optical fibers using a connector, but the optical fiber is fixed to the ferrule in the connector. Therefore, the adhesive composition used for this purpose is required to have high adhesive strength. In particular, since the optical fiber may be pulled in the long axis direction of the ferrule and a large load may be applied, high shear strength is required.
Further, without using a connector, an adhesive may be filled between optical fiber end portions to form an optical path for bonding. The adhesive composition used for forming the optical path is required to have high optical transparency in order to suppress light loss in addition to high adhesive strength.
In any of the embodiments, since the optical fiber may be installed outdoors or in an attic, a characteristic capable of maintaining a sufficient adhesive force even under a severe environment such as high temperature and high humidity is required.

  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 materials is required to have adhesiveness not only to glass but also to plastic (mainly acrylic plastic).

  Conventionally, epoxy adhesives and the like have been used as an adhesive composition for optical materials, but recent researches indicate that epoxy adhesives have a problem in adhesion durability. Further, 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 actual connection is to be made.

  Patent Document 1 describes an adhesive composition that is excellent in heat resistance, reduces the generation of bubbles during curing, and does not cause defects such as white turbidity due to bubbles. However, since the adhesive composition described in Patent Document 1 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 decrease.

JP 2002-173661 A

  An object of the present invention is to provide an adhesive composition for optical materials that is excellent in moisture and heat resistance, is capable of moisture curing, and has excellent adhesion, particularly adhesion to glass and plastic. Moreover, it aims at providing the adhesive composition for optical materials which has said characteristic, and also hardened | cured material has high transparency.

As a result of intensive studies to solve the above problems, the present inventor has found that the main chain includes an alkyl acrylate monomer unit and / or a methacrylic acid alkyl ester monomer unit, and one molecule of hydrolyzable silicon-containing group. Moisture curing is possible by mixing a polymer having at least one per unit, a reaction product obtained by reacting an epoxy compound and aminosilane, and a curing catalyst at a specific ratio, and adhesion, particularly to glass and plastics. It has been found that the adhesive composition for optical materials is excellent in adhesiveness and also in heat and moisture resistance. In addition, the inventors have found that by using a specific curing catalyst, the cured product becomes an adhesive composition for optical materials having high transparency, and the present invention has been completed.
That is, the present invention provides the following (1) to (3).

(1) (A) 100 parts by mass of a polymer in which the main chain contains an alkyl acrylate monomer unit and / or an alkyl methacrylate monomer unit and has at least one hydrolyzable silicon-containing group per molecule When,
(B) 1 to 150 parts by mass of a reaction product obtained by reacting an epoxy compound and aminosilane;
(C) The adhesive composition for optical materials containing 1-50 mass parts of curing catalysts.
Here, aminosilane in the present invention refers to a compound having at least one amino group (—NH ₂ ) and / or imino group (—NH—) and at least one hydrolyzable silicon-containing group.

  (2) The adhesive composition for optical materials according to (1), wherein the epoxy compound used in the reaction product obtained by reacting the epoxy compound (B) with aminosilane is an aromatic epoxy compound.

  (3) The adhesive composition for an optical material according to (1) or (2), wherein the (C) curing catalyst contains tetravalent tin or tetravalent zirconium.

  The adhesive composition for optical materials of the present invention is excellent in heat-and-moisture resistance, is capable of moisture curing, and is excellent in adhesiveness, particularly adhesiveness to glass and plastic. In particular, when the curing catalyst contains tetravalent tin or tetravalent zirconium, the cured product has high transparency.

Hereinafter, the adhesive composition for optical materials of the present invention will be described in detail.
The adhesive composition for optical materials of the present invention (hereinafter, also simply referred to as “the composition of the present invention”) has (A) a main chain composed of an alkyl acrylate monomer unit and / or a methacrylic acid alkyl ester monomer. 100 parts by mass of a polymer containing a body unit and having at least one hydrolyzable silicon-containing group per molecule (hereinafter also simply referred to as “polymer (A)”), (B) an epoxy compound and aminosilane It contains 1 to 100 parts by mass of a reaction product obtained by reaction and 1 to 50 parts by mass of (C) a curing catalyst.

<Polymer (A)>
The polymer (A) used in the present invention has a main chain containing an alkyl acrylate monomer unit and / or an alkyl methacrylate monomer unit, and at least one hydrolyzable silicon-containing group per molecule. It is a polymer having. If the main chain includes an acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester monomer unit, it has high adhesiveness with a plastic optical fiber mainly made of acrylic plastic, and The cured product of the adhesive composition for optical materials is excellent in compatibility with the silane coupling agent and has high transparency.

Examples of the acrylic acid alkyl ester monomer unit include, for example, methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-tert-butyl, and acrylic acid-n. -Hexyl, heptyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, lauryl acrylate, tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, behenyl acrylate, Biphenyl acrylate is mentioned.
Examples of the methacrylic acid ester monomer unit include, for example, methyl methacrylate, ethyl methacrylate, methacrylic acid-n-propyl, methacrylic acid-n-butyl, methacrylic acid isobutyl, methacrylic acid-tert-butyl, methacrylic acid- n-hexyl, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate And biphenyl methacrylate.
These may be used alone or in combination of two or more.

  The main chain of the polymer (A) is not particularly limited as long as it contains an acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester monomer unit, but the proportion of these monomer units is 50. It is preferable to exceed mass%, and it is more preferable that it is 70 mass% or more.

The main chain of the polymer (A) may contain, in addition to the acrylic acid alkyl ester monomer unit and / or the methacrylic acid alkyl ester monomer unit, a monomer unit copolymerizable therewith. . For example, a monomer unit containing a carboxy group such as acrylic acid or methacrylic acid; a monomer unit containing an amide group such as acrylamide, methacrylamide, N-methylolacrylamide, or N-methylolmethacrylamide; glycidyl acrylate, glycidyl Monomer units containing epoxy groups such as methacrylate; monomer units containing amino groups such as diethylaminoethyl acrylate, diethylaminoethyl methacrylate, aminoethyl vinyl ether; polyoxyethylene acrylate, polyoxyethylene methacrylate, etc. are moisture A copolymerization effect can be expected in terms of curability and internal curability.
In addition, monomer units derived from acrylonitrile, styrene, α-methylstyrene, alkyl vinyl ether, vinyl chloride, vinyl acetate, vinyl propionate, ethylene and the like can be mentioned.

The monomer composition of the polymer (A) is appropriately selected depending on the application and purpose.
For example, when the alkyl chain of the alkyl ester part of the monomer is long, the glass transition temperature is low, and the physical properties of the cured product are soft rubbery elastic bodies. On the other hand, when it is short, the glass transition temperature becomes high and the physical properties of the cured product become hard.
On the other hand, the physical properties after curing largely depend on the molecular weight of the polymer.
Therefore, the monomer composition of the polymer may be appropriately selected according to the desired viscosity, physical properties after curing, and the like, taking into consideration the molecular weight.

The main chain of the polymer (A) can be obtained by a controlled vinyl polymerization method or the like. For example, it can be obtained by performing a solution polymerization method, a bulk polymerization method or the like by a chain transfer agent method, a living radical polymerization method or the like, but is not particularly limited to these methods.
In the chain transfer agent method, a polymer having a functional group at the terminal is obtained by performing polymerization using a chain transfer agent having a specific functional group.
In the living radical polymerization method, a polymer having a molecular weight substantially as designed is obtained by growing the polymerization growth terminal without causing a termination reaction or the like.
The chain transfer agent method is a free radical polymerization and thus has a wide molecular weight distribution and only a polymer having a high viscosity can be obtained. However, the living radical polymerization method has a narrow molecular weight distribution (Mw / Mn is 1) because a termination reaction is unlikely to occur. About 1.5 to 1.5), a polymer having a low viscosity can be obtained, and a monomer having a specific functional group can be introduced at almost any position of the polymer. In the present invention, the method described in JP-A-2003-313397 is preferably used.
The reaction is usually carried out by mixing the above-mentioned monomer units, radical initiator, chain transfer agent, solvent and the like and reacting them at 50 to 150 ° C.

Examples of the radical initiator include azobisisobutyronitrile and benzoyl peroxide.
Examples of the chain transfer agent include mercaptans such as n-dodecyl mercaptan, tert-dodecyl mercaptan, lauryl mercaptan, and halogen-containing compounds.
Suitable examples of the solvent include non-reactive solvents such as ethers, hydrocarbons and esters.

  The hydrolyzable silicon-containing group has 1 to 3 hydroxy groups and / or hydrolyzable groups bonded to silicon atoms, 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. 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.

Among these, an alkoxysilyl group is preferable 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, and an isopropyl group An alkenyl group or an arylalkyl group is preferable.

  The number of hydrolyzable silicon-containing groups possessed by the polymer (A) is at least one per molecule. Further, the bonding position of the hydrolyzable silicon-containing group is preferably at the end of the main chain, and more preferably only at the end of the main chain. Moreover, it is preferable from the point of adhesiveness and heat-and-moisture resistance to have a hydrolyzable silyl group at both ends of the main chain.

The method for introducing a hydrolyzable silicon-containing group into the main chain of the polymer (A) is not particularly limited. For example, (i) in the presence of a mercaptan containing a hydrolyzable silicon-containing group as a chain transfer agent, (Ii) a compound having a mercapto group and a reactive functional group other than the hydrolyzable silicon-containing group as a chain transfer agent (for example, a method of polymerizing monomer units and introducing a hydrolyzable silicon-containing group at the molecular end (for example, In the presence of acrylic acid, the monomer unit is polymerized, and the resulting copolymer is a compound having a hydrolyzable silicon-containing group and a functional group capable of reacting with a Y group (for example, an isocyanate group and -Si). (OCH ₃₎ a method of introducing a hydrolyzable silicon-containing group to the compound) is reacted with molecular end and a ₃ group, compounds containing (iii) a hydrolyzable silicon-containing group (e.g., Azobisunitori Compound, disulfide compound) as an initiator to polymerize the monomer unit to introduce a hydrolyzable silicon-containing group at the molecular end, (iv) to polymerize the monomer unit by a living radical polymerization method A method of introducing a hydrolyzable silicon-containing group at the terminal, (v) a compound having a polymerizable unsaturated bond and a hydrolyzable silicon-containing group and the monomer unit, wherein one molecule of hydrolyzable silicon-containing group A method of copolymerizing by selecting polymerization conditions such as the use ratio of monomer units, the amount of chain transfer agent, the amount of radical initiator, the polymerization temperature, etc. so that at least one is introduced per unit can be mentioned.

  Among these, it is preferable that the polymer (A) is produced by adding hydrosilane having a hydrolyzable silicon-containing group to a (meth) acrylic polymer having an alkenyl group at the terminal by hydrosilylation. One.

The (meth) acrylic polymer having an alkenyl group at the end includes, for example, an organic halogen compound or a sulfonyl halide compound as an initiator and a catalyst as the group 8, 9, 10, or 11 of the periodic table. It can be produced by converting a terminal halogen group of a (meth) acrylic polymer obtained by polymerization using a metal complex having a group element as a central metal to an alkenyl group.
Here, a (meth) acrylic polymer having a halogen group at a terminal is conventionally polymerized using a halogen compound such as carbon tetrachloride, carbon tetrabromide, methylene chloride, methylene bromide as a chain transfer agent. Has been manufactured by.
However, with this method, it is usually difficult to reliably introduce halogen into both ends of the polymer.

In contrast, JP-A-1-247403 discloses a method for producing an acrylic polymer having an alkenyl group at both ends by using dithiocarbamate or diallyl disulfide having an alkenyl group as a chain transfer agent. Has been described. Japanese Patent Application Laid-Open No. Hei 6-221922 discloses that an acrylic polymer having a hydroxyl group at the terminal is produced using a hydroxyl group-containing polysulfide or an alcohol compound as a chain transfer agent, and alkenyl at the terminal using a hydroxyl group reaction. A method for producing an acrylic polymer having a group is described.
However, in these methods, it is difficult to reliably introduce an alkenyl group at the polymer terminal.

On the other hand, as a method for obtaining a (meth) acrylic polymer having a hydrolyzable silicon-containing group without passing through an alkenyl group, Japanese Patent Publication No. 3-14068 discloses a (meth) acrylic monomer containing hydrolyzable silicon. A method of polymerizing in the presence of a radical polymerization initiator having a group-containing mercaptan, a hydrolyzable silicon-containing group-containing disulfide and a hydrolyzable silicon-containing group is described. Japanese Patent Publication No. 4-55444 discloses a method of polymerizing an acrylic monomer in the presence of a hydrolyzable silicon-containing group-containing hydrosilane compound or a tetrahalosilane compound. Further, in JP-A-5-97921, an acrylic monomer is anionically polymerized using a stable carbanion having a hydrolyzable silicon-containing group as an initiator, and the terminal of the polymerization is reacted with a bifunctional electrophilic compound. Describes a method for producing an acrylic polymer having a hydrolyzable silicon-containing group.
However, these methods have problems such as introduction of a functional group into the side chain. That is, it was difficult to reliably introduce a hydrolyzable silicon-containing group at the terminal. In addition, the polymers obtained by these radical polymerizations have a problem that the molecular weight distribution is wide and the viscosity is high.

Therefore, in recent years, living radical polymerization has attracted attention as a method for reliably introducing a functional group to the terminal of an acrylic polymer. Living radical polymerization is described in JP-A-9-272714.
In particular, JP 2000-154205 A and JP 2000-178456 A detail the atom transfer radical polymerization method among the living radical polymerization methods. Here, an organic halide or a sulfonyl halide compound having a particularly highly reactive carbon-halogen bond is used as the initiator, and a periodic table, group 8, group 9, group 10 or group 11 is used as the catalyst. A metal complex having the above metal as a central metal is used. Further, in order to obtain a (meth) acrylic polymer having a functional group at the terminal, an organic halide or sulfonyl halide compound having two or more starting points is used as an initiator.

  Japanese Patent Application Laid-Open No. 2003-96106 discloses radical polymerization of (meth) acrylic acid ester monomers using 2,2′-azobis (dimethylvaleronitrile) as an initiator and n as a chain transfer agent. -Dodecyl mercaptan, tert-dodecyl mercaptan and the like are described. Here, when 2-propanol, isobutanol or the like is used as a polymerization solvent, since it has a hydrogen atom bonded to a tertiary carbon atom, it also acts as a chain transfer agent, reducing the amount of chain transfer agent used. It is described as being useful because it is preferable in terms of being able to do so and the molecular weight distribution can be controlled narrower than in the case of using an aromatic solvent.

  The polymer (A) produced from the (meth) acrylic polymer obtained by any polymerization method as described above has a molecular weight distribution of (meth) acrylic polymer obtained by ordinary radical polymerization. While it is usually 2.0 or more, it is very narrow as 1.5 or less, so it has a low viscosity. Also, the functional group introduction rate at the terminal is extremely high.

  The molecular weight of the polymer (A) is not particularly limited, but the number average molecular weight in terms of polystyrene in gel permeation chromatography (GPC) is 500 to 100,000, the degree of difficulty during polymerization, compatibility, It is preferable in terms of handling viscosity. Among them, those having a number average molecular weight of 1,000 to 50,000 are preferable from the viewpoint of balance between strength and viscosity, and those having a number average molecular weight of 2,000 to 30,000 are points such as ease of handling such as workability and adhesiveness. And more preferable.

  A polymer (A) is used individually or in mixture of 2 or more types.

  A well-known thing can be used as a polymer (A). Specific examples include SMAP (Kaneka Telechelic Polyacrylate) SA100S, SA110S, SA120S and SA200SX manufactured by Kaneka Chemical Co., Ltd. and Kaneka MS Polymer S943 manufactured by Kaneka Chemical Co., Ltd.

<(B) Reactant formed by reacting epoxy compound with aminosilane>
The composition of the present invention is a reaction product obtained by reacting (B) an epoxy compound and aminosilane with respect to 100 parts by mass of the polymer (A) (hereinafter also simply referred to as “reaction product (B)”). 1 to 150 parts by mass. Since the composition of this invention contains the reaction material (B), it is excellent in adhesiveness and heat-and-moisture resistance. Since the reactant (B) plays a role as a compatibilizing agent, an adhesion-imparting agent, and an adhesive strength stabilizer, it is considered that the reaction product (B) is excellent in transparency, adhesiveness, and heat-and-moisture resistance.
Moreover, when content of a reaction material (B) is said range, it is excellent in compatibility (transparency), adhesiveness, and heat-and-moisture resistance, and is highly weather-resistant. 30-150 mass parts is preferable at the point which is excellent by this characteristic, and 50-150 mass parts is especially preferable.

The epoxy compound used in the reactant (B) is not particularly limited, and examples thereof include bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, pyrocatechol, resorcinol, cresol novolac, and tetrabromobisphenol. G, glycidyl ether type obtained by the reaction of polychlorophenol such as A, trihydroxybiphenyl, bisresorcinol, bisphenol hexafluoroacetone, tetramethylbisphenol F, bixylenol and epichlorohydrin; glycerin, neopentyl glycol, ethylene glycol, propylene Aliphatic polyvalent alcohols such as glycol, butylene glycol, hexylene glycol, polyethylene glycol and polypropylene glycol Polyglycidyl ether type obtained by the reaction of alcohol with epichlorohydrin; glycidyl ether ester type obtained by the reaction of hydroxycarboxylic acid such as p-oxybenzoic acid and β-oxynaphthoic acid with epichlorohydrin; phthalic acid, methylphthalic acid, Polyglycidyl ester type derived from polycarboxylic acids such as isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylenehexahydrophthalic acid, trimellitic acid, polymerized fatty acid; Glycidylaminoglycidyl ether type derived from aminophenol, aminoalkylphenol, etc .; Glycidylaminoglycidyl ester type derived from aminobenzoic acid; Aniline, Toluidine, Tribro Glycidylamine type derived from moaniline, xylylenediamine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, etc .; epoxidized polyolefin, glycidylhydantoin, glycidylalkylhydantoin And triglycidyl cyanurate; monoepoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, glycidyl benzoate, and styrene oxide.
In addition, a resin obtained by polymerizing a compound having two or more epoxy groups in one molecule can also be used.
These epoxy compounds may be used alone or in combination of two or more.

  Among these, an aromatic epoxy compound such as a glycidyl ether type obtained by a reaction between the polyhydric phenol and epichlorohydrin is preferable in terms of excellent adhesive strength. Here, the aromatic epoxy compound is a compound having at least one aromatic ring and one epoxy group in one molecule. In particular, bisphenol A 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.

  The epoxy compound may be a commercially available product or may be produced. Manufacturing conditions are not particularly limited, and can be performed by known methods and conditions.

The aminosilane used in the reactant (B) may be a compound having at least one amino group (—NH ₂ ) and / or imino group (—NH—) and at least one hydrolyzable silicon-containing group. Specific examples include, but are not limited to, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylethyldiethoxysilane, and bistrimethoxysilylpropyl. Amine, bistriethoxysilylpropylamine, bismethoxydimethoxysilylpropylamine, bisethoxydiethoxysilylpropylamine, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyl Dimethoxysilane, N-β ( Minoethyl) γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylethyldiethoxysilane, 3,3-dimethyl-4-aminobutyltrimethoxysilane, 3,3-dimethyl-4-aminobutyl Methyldimethoxysilane, (N-cyclohexylaminomethyl) methyldiethoxysilane, (N-cyclohexylaminomethyl) triethoxysilane, (N-phenylaminomethyl) methyldimethoxysilane, (N-phenylaminomethyl) trimethyloxysilane and Examples thereof include compounds having a structure represented by formulas (I) and (II).

Among these, (N-cyclohexylaminomethyl) methyldiethoxysilane, (N-cyclohexylaminomethyl) triethoxysilane, (N-phenylaminomethyl) methyldimethoxysilane, (N -Phenylaminomethyl) trimethyloxysilane and compounds having structures represented by the above formulas (I) and (II) are preferred.
The said aminosilane may be used independently and may use 2 or more types together.

  Moreover, the said aminosilane may use a commercial item and may manufacture it. Manufacturing conditions are not particularly limited, and can be performed by known methods and conditions. Examples of commercially available products include Alink-15 (manufactured by Nihon Unicar), Y-9669 (manufactured by Nihon Unicar), GENIOSIL (XL924, XL926, XL972, XL973, all manufactured by Wacker), A-1100 (Nihon Unicar). Co., Ltd.), A1110 (Nihon Unicar Co., Ltd.), Y11637 (Nihon Unicar Co., Ltd.) and the like.

The reactant (B) is obtained by reacting an epoxy compound and aminosilane. The reaction can be performed by a known method.
Moreover, the ratio which mixes an epoxy compound and aminosilane can be suitably set according to the characteristic requested | required of the composition of this invention. Although this ratio is not particularly limited, the ratio (Y / X) of the number (Y) of amino groups and / or imino groups of aminosilane to the number of epoxy groups (X) of the epoxy compound is 0.1 to 0. .9 is preferable because an epoxy group is contained in the obtained reaction product and adhesion, heat resistance and storage stability can be imparted to the composition of the present invention. It is more preferable that it is 0.1-0.6 by the point which is excellent by this characteristic.
Moreover, when the said ratio is 1.1-2.0, it will contain aminosilane more than a stoichiometry, and since a cure rate will become quick and it will harden | cure rapidly to an inside, it is preferable. In this case, since many hydrolyzable silicon-containing groups are contained in the reaction product, the cured product of the composition of the present invention has high transparency because it is excellent in adhesive strength and heat-and-moisture resistance and is easily compatible with other components. Have. 1.1-1.5 are more preferable at the point which is excellent by these characteristics.

  The first aspect of the preferred reactant (B) is obtained by reacting an aminosilane having one imino group in one molecule with one equivalent of an aromatic epoxy compound having two epoxy groups in one molecule. It is a thing. Specifically, for example, a reaction having a structure represented by the following formula (III) obtained by reacting 1 equivalent of a compound having a structure represented by the above formula (I) with bisphenol A glycidyl ether. Things.

  A preferred second embodiment of the reactant (B) is obtained by reacting 2 equivalents of an aminosilane having one imino group in one molecule with an aromatic epoxy compound having two epoxy groups in one molecule. It is a thing. Specifically, for example, a reaction having a structure represented by the following formula (IV) obtained by reacting 2 equivalents of a compound having a structure represented by the above formula (I) with bisphenol A glycidyl ether. Things.

  The first and second aspects of the reactant (B) may be used alone or in combination, but are preferably used together in terms of both curing speed and storage stability. When used in combination, the mass ratio of the first aspect of the reactant (B) to the second aspect (first aspect / second aspect) is 1/9 in terms of both curing speed and storage stability. ~ 9/1 is preferable, and 2/8 to 8/2 is more preferable.

<(C) Curing catalyst>
The composition of this invention contains 1-50 mass parts of curing catalysts with respect to 100 mass parts of polymers (A). Even if the composition obtained by removing the curing catalyst from the composition of the present invention can be cured by moisture, it is not practical because the curing time is long. By containing a curing catalyst, the composition of the present invention can promote the progress of the curing reaction to shorten the working time for curing, thereby reducing the tack-free time and being practically excellent.
Moreover, when the content of the curing catalyst is within the above range, the effect of the curing catalyst can be sufficiently exerted, there is no problem with compatibility with other components, and no local heat generation or foaming occurs during curing. In this respect, 1 to 30 parts by mass is preferable, and 1 to 20 parts by mass is particularly preferable.

  The curing catalyst is not particularly limited, and examples thereof include zinc octoate, iron octoate, manganese octoate, tin octoate, zinc naphthenate, iron naphthenate, tin butanoate, tin caprylate, and tin oleate. Carboxylic acid metal salt; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin dioleate, dioctyltin dilaurate, diphenyltin diacetate, dibutyltin oxide, reaction product of dibutyltin oxide and phthalate ester, dibutyltin Organotin compounds such as dimethoxide, dibutyltin (triethoxysiloxy), dibutyltin silicate; tin chelate compounds such as dibutyltin diacetylacetonate; tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, tetra-2-ethylhexyl Titanic acid esters such as oxytitanium and tetraisopropenyloxytitanium; diisopropoxytitanium bis (acetylacetonate), diisopropoxytitanium bis (ethylacetoacetate), 1,3-propanedioxytitanium bis (acetylacetonate), 1 , 3-propanedioxytitanium bis (ethylacetoacetate), titanium chelate compounds such as titanium tris (acetylacetonate); zirconium alkoxides such as tetraisopropoxyzirconium, tetrabutoxyzirconium, tributoxyzirconium stearate; Zirconium chelate compounds such as acetylacetonate); such as triethoxyaluminum, tripropoxyaluminum and tributoxyaluminum. Aluminum chelates such as diisopropoxyaluminum (ethyl acetoacetate), aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate); butylamine, hexylamine, octylamine, dodecylamine, oleylamine, cyclohexylamine Primary amines such as benzylamine; secondary amines such as dibutylamine; polyamines such as diethylenetriamine, triethylenetetramine, guanidine, diphenylguanidine, xylylenediamine; triethylenediamine, morpholine, N-methylmorpholine, Cyclic amines such as 2-ethyl-4-methylimidazole, 1,8-diazabicyclo [5.4.0] -7-undecene; monoethano Amino alcohol compounds such as uramine, diethanolamine and triethanolamine; amine compounds such as aminophenol compounds such as 2,4,6-tris (dimethylaminomethyl) phenol and carboxylates thereof; such as benzyltriethylammonium acetate Quaternary ammonium salt; low molecular weight amide resin obtained from excess polyamine and polybasic acid; reaction product of excess polyamine and epoxy compound. These curing catalysts may be used alone or in combination of two or more.

  Among these, a metal compound is preferable because it is difficult to volatilize during storage and handling, and among them, an organic tin compound, a tin chelate compound, and a titanate ester are preferable because excellent catalytic ability can be obtained with a small amount of compounding.

Moreover, the curing catalyst in which the cured product of the composition of the present invention has high transparency is preferable. Specifically, a curing catalyst containing tetravalent tin or tetravalent zirconium is preferable. Since the composition of the present invention containing the curing catalyst has high adhesiveness and the cured product has high transparency, it is suitably used as an optical path adhesive composition for joining optical fibers.
Examples of the curing catalyst containing tetravalent tin include the above organic tin compounds. Examples of commercially available products include dibutyltin silicate (U303, manufactured by Nitto Kasei Co., Ltd.), dibutyltin dilaurate (U-100, manufactured by Nitto Kasei Co., Ltd.), dibutyltin diacetate (U-220, manufactured by Nitto Kasei Co., Ltd.), dibutyltin. And dimethoxide (SCAT-27, manufactured by Sansha Co., Ltd.).
Examples of the curing catalyst containing tetravalent zirconium include the above zirconium alkoxide and zirconium chelate compound. Commercially available products include, for example, tetranormal propoxyzirconium (Orgatechx ZA-40, manufactured by Matsumoto Pharmaceutical Co., Ltd.), zirconium tetraacetylacetonate (Orgatechx ZC-150, manufactured by Matsumoto Pharmaceutical Co., Ltd.), zirconium tributoxy systemate ( Olgatics ZB-320, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and the like.

<Additives>
If necessary, the composition of the present invention is a polymer other than the polymer (A), a silane coupling agent, a reinforcing agent, a reaction retarding agent, an anti-aging agent, an oxidation, as long as the object of the present invention is not impaired. Inhibitors, pigments (dyes), plasticizers, thixotropic agents, UV absorbers, flame retardants, solvents, surfactants (including leveling agents), dispersants, dehydrators, adhesion promoters, antistatic agents, fillers Various additives such as can be contained.

  By adding a silane coupling agent, adhesion and heat-and-moisture resistance can be increased. In the present specification, the silane coupling agent is a compound having at least one functional group reactive with an organic group and a hydrolyzable silicon group in the molecule other than the reactant (B). Although it does not specifically limit as a functional group reactive with an organic group, From a handling point, at least 1 chosen from a methacryl group, an acryl group, an isocyanate group, an isocyanurate group, a vinyl group, a carbamate group, an epoxy group, for example. Preferred examples are functional groups. From the viewpoint of curability and adhesiveness, a methacryl group, an acrylic group, and an epoxy group are more preferable. The hydrolyzable silicon group is not particularly limited, but is preferably an alkoxysilyl group from the viewpoint of handleability, and more preferably a methoxysilyl group or an ethoxysilyl group from the viewpoint of reactivity.

  Preferred silane coupling agents include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane. , Alkoxysilanes having a methacrylic group or an acrylic group such as methacryloxymethyltriethoxysilane, acryloxymethyltrimethoxysilane, acryloxymethyltriethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Triethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxy Epoxy group-containing silane compound such as silane can be exemplified.

  Although it does not specifically limit as addition amount in the case of using a silane coupling agent, Although it can set variously, 1-100 mass parts is preferable with respect to 100 mass parts of said polymers (A). When the addition amount is within this range, the adhesiveness and heat-and-moisture resistance can be improved, and the physical properties of the cured product are not adversely affected. 1-50 mass parts is more preferable at the point which is excellent by this characteristic.

  Moreover, the composition of this invention can improve intensity | strength by adding a reinforcing agent. Examples of the reinforcing agent include organic fine particles and inorganic fine particles. From the viewpoint of heat resistance, inorganic fine particles are preferred. Examples of the inorganic fine particles include silica, titania, alumina, zirconia, ceria, calcium carbonate, and the like. The amount of these reinforcing agents added is preferably 100 parts by mass or less, and more preferably 60 parts by mass or less with respect to 100 parts by mass of the (A) polymer (A). The particle diameter of these reinforcing agents is preferably 1 μm or less and more preferably 0.5 μm or less in order to ensure the transparency of the adhesive layer. In addition, it is preferable from the viewpoint of transparency that the refractive index of the reinforcing agent to be added is substantially equal to the refractive index of the matrix.

The composition of the present invention is moisture curable and can be used for an adhesive composition for a one-component optical material or an adhesive composition for a two-component optical material. When the composition of the present invention is exposed to moisture, the curing reaction proceeds by hydrolysis of the hydrolyzable silicon-containing group. Since the adhesive composition for a one-component optical material is cured by moisture in the air, the workability is excellent.
The composition of the present invention can be cured in a few minutes by moisture in the air by increasing the amount of the curing catalyst. Moreover, it can be set as the adhesive composition for optical materials which has a pot life of several hours by reducing the quantity of a curing catalyst.

  Moreover, it has 100 mass parts of said polymers (A), 1-100 mass parts of the reaction material formed by making said (B) epoxy compound and aminosilane react, and said (C) 1-50 mass parts of curing catalysts. When the composition is a liquid A and the liquid B is a two-component adhesive composition for an optical material, the curing is rapid and the deep part curability is excellent. It is preferable to mix 1-50 mass parts of B liquid (water) with respect to 100 mass parts of said polymers (A). Within this range, the curing rate is moderate, and the pot life is sufficient for the bonding operation. Moreover, since it is excellent in deep part curability, the adhesive composition for optical materials with high adhesive strength can be obtained. It is more preferable to mix 1-30 mass parts by the point which is excellent by this characteristic.

  In both the one-component and two-component adhesive compositions for optical materials, the curing time can be shortened by heat treatment as necessary.

  The method for producing the composition of the present invention is not particularly limited. For example, the above-described various components and additives to be added as desired are preferably mixed under a reduced pressure or in an inert atmosphere using a mixing device such as a ball mill. It is obtained by sufficiently kneading and uniformly dispersing.

  The composition of the present invention comprises a polymer (polymer) having a main chain containing an acrylic acid alkyl ester monomer unit and / or a methacrylic acid alkyl ester monomer unit and having at least one hydrolyzable silicon-containing group per molecule. (Corporation (A)), a reaction product (reaction product (B)) obtained by reacting an epoxy compound and aminosilane, and a curing catalyst are contained in a specific ratio, so that moisture curing is possible and adhesiveness, particularly Excellent adhesion to glass and plastic, and also excellent in heat and moisture resistance. Moreover, when using a specific curing catalyst, the cured product has high transparency. Therefore, the composition of the present invention can be suitably used for bonding optical materials.

Examples of the optical material to be bonded to the composition of the present invention 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 materials constituting these optical materials include glass materials, plastic materials, metals, organic-inorganic composite materials, and the like.
That is, the composition of the present invention can be suitably used for adhesion of, for example, glass optical fibers, plastic optical fibers, zirconia ferrules, crystallized glass ferrules, and the like. The optical fiber made of glass or plastic and the ferrule made of zirconia or crystallized glass can be bonded.

  When assembling these optical materials, the composition of the present invention is placed between a first optical material (for example, an optical fiber) and a second optical material (for example, a ferrule), and then cured to obtain a desired strength. A connecting portion can be formed.

  Moreover, you may form a primer layer in the surface of the adhesive body joined using the composition of this invention. By forming the primer layer, the adhesiveness can be increased. Examples of the compound forming the primer layer include a sulfur-containing alkoxysilane compound having at least one sulfur atom in one molecule and having at least two alkoxy groups bonded to a silicon atom, and at least one molecule in one molecule. A nitrogen-containing alkoxysilane compound having at least two alkoxy groups having one nitrogen atom and bonded to a silicon atom; at least an alkoxy group having at least one epoxy group in one molecule and bonded to a silicon atom; Examples thereof include silane coupling agents such as two epoxy-containing alkoxysilane compounds and their hydrolysis / dehydration condensation compounds.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
(Synthesis of reactant (B1) and reactant (B2))
First, a reactant (B1) and a reactant (B2) used as a reactant obtained by reacting the epoxy compound with aminosilane were synthesized.
The reactant (B1) is a mixture of 1 mol of an epoxy compound (bisphenol A glycidyl ether, trade name YD128, manufactured by Tohto Kasei Co., Ltd.) and 1 mole of aminosilane (trade name Alink-15, manufactured by Nihon Unicar Company) under a nitrogen atmosphere. And obtained by reaction at 50 ° C. for 24 hours.
The reactant (B2) was synthesized in the same manner as the reactant (B1) except that the amount of aminosilane was 2 mol.

(Examples 1-3 and Comparative Examples 1-2)
The components shown in Table 1 below were mixed to obtain a one-pack type adhesive composition.

Each component in Table 1 is as follows.
Polymer (A): Trade name SMAP SA100S, Kaneka Chemical Co., Ltd. Epoxysilane: Trade name A187, Nihon Unicar Co., Ltd. Curing catalyst (dibutyltin silicate): Trade name U303, Nitto Kasei Co., Ltd.

After the obtained adhesive composition was cured for 3 days in an environment of 20 ° C. and 65% RH, a glass plate was used as the adherend according to JIS K 6852-1994, and an acrylic plate (PMMA ) Was used (in Tables 1 and 2, respectively, initial compression shear strength (glass) and initial compression shear strength (acrylic)).
Next, the obtained adhesive composition was cured for 3 days in an environment of 20 ° C. and 65% RH, and further subjected to wet heat degradation for 10 days in an environment of 80 ° C. and 95% RH. Compressive shear strength when glass is used as the adherend and acrylic plate in the same manner (compressed shear strength (glass) after wet heat degradation (glass), wet heat in Tables 1 and 2, respectively) Compressive shear strength (acrylic) after deterioration) was measured.
The obtained adhesive composition was cured in an environment of 20 ° C. and 65% RH for 3 days to form a film having a thickness of 20 μm, and then visible using a spectrophotometer at a wavelength of 400 to 900 nm. The light transmittance (%) was measured.
The results are shown in Table 1 below.

The adhesive compositions of Examples 1 to 3 have high initial compressive shear strength in both the glass plate and the acrylic plate, have a small decrease in compressive shear strength after wet heat deterioration, and are excellent in visible light transmittance. It was.
On the other hand, the adhesive composition of Comparative Example 1 had low initial compression shear strength and compression shear strength after wet heat degradation for both the glass plate and the acrylic plate.
Moreover, although the adhesive composition of the comparative example 2 increased the addition amount of an epoxy silane without putting a reaction material (B) with respect to the adhesive composition of Examples 1-3, a glass plate, The initial compressive shear strength was low for any of the acrylic plates, and the compressive shear strength after wet heat degradation was significantly reduced, which was problematic for practical use.

(Examples 4-6, Comparative Examples 3-5)
After mixing each component of the A liquid in the amount shown in Table 2 to make the A liquid, the components in the B liquid were further added and mixed in the amounts shown in Table 2 and mixed to form a two-component type. An adhesive composition was obtained.
In Table 2, each component other than the epoxy adhesive composition (trade name: Epotec 353ND, manufactured by Muromachi Technos) is the same as each component in Table 1 above.
Next, the initial compression shear strength (glass) and the initial compression shear strength (acrylic) were obtained using the obtained two-component adhesive composition under the same conditions and methods as in Examples 1 to 3 and Comparative Examples 1 and 2. ), Compression shear strength after wet heat degradation (glass), compression shear strength after wet heat degradation (acrylic), and visible light transmittance (%) at a wavelength of 400 to 900 nm.
The results are shown in Table 2.

The adhesive compositions of Examples 4 to 6 have high initial compressive shear strength in both the glass plate and the acrylic plate, have a small decrease in compressive shear strength after wet heat deterioration, and are excellent in visible light transmittance. It was.
On the other hand, the adhesive composition of Comparative Example 3 had low initial compressive shear strength and compressive shear strength after wet heat degradation for both the glass plate and the acrylic plate.
Moreover, although the adhesive composition of the comparative example 4 increased the addition amount of an epoxysilane without putting a reaction material (B) with respect to the adhesive composition of Examples 4-6, a glass plate, The initial compressive shear strength was low for any of the acrylic plates, and the compressive shear strength after wet heat degradation was significantly reduced, which was problematic for practical use.
Comparative Example 5 is an epoxy adhesive composition that has been conventionally used as an adhesive composition for optical materials. However, the compression shear strength significantly decreases after wet heat deterioration, and the visible light transmittance is also low. It was.

(Example 7)
<Bonding of optical fibers>
FIG. 1 is a schematic cross-sectional view of an example in which optical fibers are bonded to each other using the composition of the present invention. As shown in FIG. 1, each of first and second single-mode glass optical fibers (each about 1 m in length) 1, 21 each having a polymer coating layer 4, a core portion 2, and a cladding portion 3. The polymer coating layer 4 is removed over a length of 2 cm at the ends, and the ends are abutted so as to have an interval of about 25 μm and aligned on an optical bench (not shown). Next, light when a laser beam having a wavelength of 1550 nm is incident from the other end of the first optical fiber 1, passed through the first optical fiber 1, and emitted from the other end of the second optical fiber 21. The fiber placement was adjusted to minimize the loss value of the fiber. In this state, the adhesive composition of Example 1 was applied between the two fibers, and left to stand in an environment of 20 ° C. and 65% RH for 3 days. The first optical fiber 1 and the second optical fiber 21 were joined.
Next, for the one in which the first optical fiber and the second optical fiber are joined, and the one that is left to stand in an environment of 80 ° C. and 95% RH for 10 days, the adhesive part is placed between both hands. I grabbed the optical fiber and pulled it lightly, but none of the bonded parts were destroyed. In addition, the light loss value after curing the adhesive composition was almost the same as the light loss value before applying the adhesive composition.

(Example 8)
<Bonding of optical fiber and ferrule>
FIG. 2 is a schematic cross-sectional view of an example in which an optical fiber and a ferrule are bonded using the composition of the present invention. As shown in FIG. 2, the portion of the single-mode glass optical fiber (about 1 m in length) 31 having the polymer coating layer 4, the core portion 2 and the cladding portion 3 is removed from the end of the polymer coating layer 4 over a length of 2 cm. Then, the adhesive composition for optical material of Example 1 was applied, inserted into the cavity of the ferrule 7 fixed to the plug 8, and allowed to stand in an environment of 20 ° C. and 65% RH for 3 days. The optical fiber 31 and the ferrule 7 were joined through the adhesive layer 6. Thereafter, the end face of the ferrule was precisely polished.
Next, the optical fiber and the ferrule joined together and the optical fiber and the ferrule left for 10 days in an environment of 80 ° C. and 95% RH were grabbed and gently pulled by the ferrule and the optical fiber. Was never destroyed.

FIG. 1 is a schematic cross-sectional view of an example in which optical fibers are bonded to each other using the composition of the present invention. FIG. 2 is a schematic cross-sectional view of an example in which an optical fiber and a ferrule are bonded using the composition of the present invention.

Explanation of symbols

1, 21, 31 Optical fiber 2 Optical fiber core 3 Optical fiber cladding 4 Polymer coating layer 5 Adhesive layer (optical path)
6 Adhesive layer 7 Ferrule 8 Plug

Claims (3)

(A) 100 parts by mass of a polymer in which the main chain includes an alkyl acrylate monomer unit and / or a methacrylic acid alkyl ester monomer unit, and has at least one hydrolyzable silicon-containing group per molecule;
(B) 1 to 150 parts by mass of a reaction product obtained by reacting an epoxy compound and aminosilane;
(C) The adhesive composition for optical materials containing 1-50 mass parts of curing catalysts.   The adhesive composition for optical materials according to claim 1, wherein the epoxy compound used in a reaction product obtained by reacting the (B) epoxy compound with aminosilane is an aromatic epoxy compound.   The adhesive composition for optical materials according to claim 1 or 2, wherein the (C) curing catalyst contains tetravalent tin or tetravalent zirconium.

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