JPH09316421A - Adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an adhesive having high refractive index and high adhesive strength. SOLUTION: This adhesive contains <=10 pts.wt. of a silane coupling agent or a titanate coupling agent based on 100 pts.wt. of a thermosetting resin composition comprising 5-100wt.% of an epoxy compound expressed by the formula R<1> , R<2> , R<3> and R<4> are same or different and are each hydrogen atom, a halogen atom or a 1-6C alkyl group; (n) is an integer of 0-10} and 0-95wt.% of a compound copolymerizable with the epoxy compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for bonding materials such as an optical material and an electronic material having a high refractive index or between these materials and another substance.

[0002]

2. Description of the Related Art Among adhesives for adhering materials such as optical materials and electronic materials, or adhesives for adhering these materials and other substances, thermoplastic adhesives are particularly required as optical adhesives. Resins such as Canadian balsam, epoxy resin adhesive, and acrylic resin adhesive are known. However, the refractive index of Canadian balsam is 1.52, and the refractive index of epoxy resin adhesives and acrylic resin adhesives is 1.
Since it is about 51 to 1.58, when these adhesives are used as an adhesive of a high refractive index material having a refractive index of 1.60 or more, there is a drawback that the light transmittance is lowered.

In order to improve these disadvantages, Japanese Patent Application Laid-Open No.
Japanese Patent No. 3237 discloses an adhesive containing a compound having a thiol (meth) acrylate group and a compound having an epoxy group. However, the compound having a thiol (meth) acrylate group has a high refractive index but a large curing shrinkage, and has problems in distortion and adhesiveness. On the other hand, when the content of the compound having an epoxy group is increased to enhance the adhesiveness, there is a problem that the refractive index is lowered, and it is difficult to obtain an adhesive that satisfies both the high refractive index and the high adhesiveness.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to provide an adhesive having a high refractive index and a high adhesive force.

[0005]

DISCLOSURE OF THE INVENTION The gist of the present invention is to use an adhesive as an epoxy compound 5-1 represented by the following general formula (I).
100% by weight of a curable resin composition comprising 0 to 95% by weight of a compound copolymerizable with the epoxy compound
It is configured to contain 10 parts by weight or less of a silane coupling agent or a titanate coupling agent with respect to parts by weight.

[0006]

Embedded image

In the formula, R ¹ , R ² , R ³ and R ⁴ are the same or different and each is a hydrogen atom, a halogen atom or a carbon number of 1 to 6.
Represents an alkyl group. n represents an integer of 0 to 10. R ¹ in the epoxy compound represented by the general formula (I),
As the halogen atom represented by R ² , R ³ and R ⁴ ,
Examples of the alkyl group having 1 to 6 carbon atoms include chlorine, bromine and iodine, and are not particularly limited, and straight-chain or branched alkyl groups such as methyl, ethyl, n-propyl, is
o-propyl, n-butyl, sec-butyl, tert
-Butyl, pentyl, hexyl and the like can be mentioned. Preferably, R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms. Preferably, n is 0-5.

The epoxy compound represented by the general formula (I) is not particularly limited, and examples thereof include the following. Bis [4- (2,3-epoxypropylthio) phenyl] sulfide Bis [4- (2,3-epoxypropylthio) -3-methylphenyl] sulfide Bis [4- (2,3-epoxypropylthio)- 3,5
-Dimethylphenyl] sulfide Bis [4- (2,3-epoxypropylthio) -2,
3,5,6-Tetramethylphenyl] sulfide

Bis [4- (2,3-epoxypropylthio) -3-hexylphenyl] sulfide Bis [4- (2,3-epoxypropylthio) -3-chlorophenyl] sulfide Bis [4- (2,3) -Epoxypropylthio) -3,5
-Dichlorophenyl] sulfide bis [4- (2,3-epoxypropylthio) -2,
3,5,6-Tetrachlorophenyl] sulfide

Bis [4- (2,3-epoxypropylthio) -3-bromophenyl] sulfide Bis [4- (2,3-epoxypropylthio) -3,5
-Dibromophenyl] sulfide bis [4- (2,3-epoxypropylthio) -2,
3,5,6-Tetrabromophenyl] sulfide.

Preferably, bis [4- (2,3-epoxypropylthio) phenyl] sulfide, bis [4-
(2,3-Epoxypropylthio) -3,5-dimethylphenyl] sulfide, bis [4- (2,3-epoxypropylthio) -3,5-dibromophenyl] sulfide, bis [4- (2,3) -Epoxypropylthio) -3
-Methylphenyl] sulfide.

The method for producing the above-mentioned epoxy compound is not particularly limited. For example, a method in which epichlorohydrin is added to a dithiol compound represented by the following general formula (II) and then a ring-closing reaction is carried out (J .Appl.Poly.S
ci,. 39, 1623 (1990)).

[0013]

Embedded image

In the formula, R ¹ , R ² , R ³ and R ⁴ are the same as defined above. The compound copolymerizable with the epoxy compound is not particularly limited, and examples thereof include a monomer having an epoxy group, an oligomer having an epoxy group, a compound having active hydrogen, and an acid anhydride. Examples of the compound having active hydrogen include a monomer having a thiol group, an oligomer having a thiol group, a monomer having an amino group, a polymer having an amino group, and a polymer having an amide group. Depending on the purpose of use, not only monofunctional compounds but also polyfunctional compounds can be selected. These compounds can be used alone or in combination of two or more.

The epoxy group-containing monomer and the epoxy group-containing oligomer are not particularly limited, and examples thereof include allyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, sec-butylphenyl glycidyl ether, monofunctional glycidyl ethers such as tert-butylphenyl glycidyl ether and 2-methyloctyl glycidyl ether;

1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol Polyfunctional glycidyl ethers such as diglycidyl ether;

Glycidyl acrylate, glycidyl methacrylate, diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate, dimethyldiglycidyl hexahydrophthalate, and other glycidyl esters; bisphenol A glycidyl ether, bisphenol F glycidyl ether, brominated bisphenol A Glycidyl ether, biphenol glycidyl ether, tetramethyl biphenol glycidyl ether, resorging glycidyl ether, hydroquinone glycidyl ether, dihydroxynaphthalene glycidyl ether, bisphenol novolac resin glycidyl ether, phenol novolac resin glycidyl ether, cresol novolac resin glycidyl ether, dicycline Dicyclopentadiene phenolic resin glycidyl ethers, terpene phenol resin glycidyl ethers, glycidyl ethers such as naphthol novolak resin glycidyl ether;

3,4-epoxycyclohexylmethyl-
3,4-epoxycyclohexanecarboxylate,
3,4-epoxycyclohexylethyl-3,4-epoxycyclohexanecarboxylate, vinylcyclohexene dioxide, allylcyclohexene dioxide,
3,4-epoxy-4-methylcyclohexyl-2-propylene oxide, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-m-dioxane, bis (3,4- Epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxycyclohexylmethyl) ether, bis (3,4-epoxycyclohexylmethyl) ether, bis (3,4-epoxycyclohexyl) diethyl Examples thereof include alicyclic epoxy resin compounds such as siloxane.

Preferably, ethylene glycol diglycidyl ether, glycidyl acrylate, glycidyl methacrylate, bisphenol A glycidyl ether,
Brominated bisphenol A glycidyl ether, 3,4
-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

The monomer having a thiol group is not particularly limited, and examples thereof include the followings. Examples of the aliphatic thiols include propyl mercaptan, butyl mercaptan, pentyl mercaptan, octyl mercaptan, 2-mercaptoethanol, 3-mercaptobutanol, 8-mercaptooctanol, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,2
-Cyclohexanedithiol, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, butanediol bisthioglycolate, butanediol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate , Pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, tris (2-mercaptoethyl) isocyanurate, tris (3-mercaptopropyl) isocyanurate, bis (2-mercaptoethyl) sulfide, bis (3-mercapto) Propyl) sulfide, bis (4-mercaptobutyl) sulfide, bis (8-mercaptooctyl) sulfide, 1,2-bis [(2-mercapto Ethyl) thio] -3-mercaptopropane, 1,2-xylylenedithiol, tetrakis (mercaptomethyl) methane, 1,3-xylylenedithiol, 1,4-xylylenedithiol, N, N ',
Examples thereof include N ″ -tris (mercaptoethylcarbonyloxyethyl) isocyanurate and N, N ′, N ″ -tris (mercaptomethylcarbonyloxyethyl) isocyanurate.

Examples of aromatic thiols include 1,
2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 4-methyl-1,2
Examples thereof include benzenedithiol, 4-butyl-1,2-benzenedithiol, 4-chloro-1,2-benzenedithiol and 4,4'-bis (mercaptophenyl) sulfide.

Preferably 1,2-ethanedithiol,
Trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, bis (2
-Mercaptoethyl) sulfide, 1,2-bis [(2
-Mercaptoethyl) thio] -3-mercaptopropane, 1,3-benzenedithiol, 4,4'-bis (mercaptophenyl) sulfide.

Examples of the oligomer having a thiol group include, for example, Thiokol LP-5 manufactured by Toray Thiokol Co.
5, Capcure-3-800 manufactured by Yuka Shell Epoxy Co., Ltd.
And the like. Examples of the monomer having an amino group and the polymer having an amino group include aliphatic amines such as diethylenetriamine, triethylenetetramine, polymethylenediamine, polyetherdiamine, m-xylylenediamine, and tetrachloro-p-xylylenediamine. Menthanediamine, N-aminoethylpiperazine, 1,3-diaminocyclohexane, N-methylpiperazine, hydroxyethylpiperazine, N,
Alicyclic amines such as N'-dimethylpiperazine; m-phenylenediamine, 4,4'-methylenedianiline,
Aromatic amines such as 4,4'-thiodianiline, 2,4-toluenediamine, diaminodiphenylsulfone and the like can be mentioned.

As the above-mentioned polymer having an amide group,
For example, Tomeide 252 and Tomeide 296 manufactured by Fuji Kasei Co., Ltd. may be mentioned. Examples of the acid anhydride include aliphatic acid anhydrides such as dodecenyl succinic anhydride and polyadipic anhydride; alicyclic acid anhydrides such as methyltetrahydrophthalic anhydride and hexahydrophthalic anhydride; phthalic anhydride And aromatic anhydrides such as trimellitic anhydride.

The silane coupling agent is not particularly limited, and examples thereof include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane. Ethoxysilane, γ-
Mercaptopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)
-Γ-aminopropyltrimethoxysilane, N-β-
(Aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β
-(N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, γ-anilinopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxy Silane, hexamethyldisilazane, vinyltrimethoxysilane, octadecyldimethyl (3- (trimethoxysilyl) propyl)
Ammonium chloride, γ-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltriethoxysilane, benzyltrimethylsilane, vinyltris (2-methoxyethoxy) silane, γ-methacryloxypropyltris (2-methoxy Ethoxy) silane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-ureidopropyltriethoxysilane,
Examples thereof include γ-isocyanurpropyltriethoxysilane and n-octylethoxysilane.

Preferably, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,
γ-mercaptopropylmethyldimethoxysilane, γ-
Aminopropyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane.

The titanate coupling agent is not particularly limited and includes, for example, isopropyl isostearoyl titanate, isopropyl tri-n-dodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate. , Tetraoctyl bis (ditridecyl phosphite) titanate,
Tetra (2,2-dialkyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryloyl Examples thereof include isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, and the like.

Preferably, isopropyl isostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-dialkyloxymethyl-1-butyl) bis (ditridecyl) phosate. Phyto titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, and isopropyl tri (N-aminoethyl-aminoethyl) titanate.

The adhesive of the present invention is the above-mentioned epoxy compound 5
A curable resin composition consisting of ˜100% by weight and 0 to 95% by weight of a compound copolymerizable with the epoxy compound is used as a constituent component. When the content of the epoxy compound is less than 5% by weight, the refractive index of the adhesive decreases, so the content is limited to the above range.

The adhesive of the present invention contains 10 parts by weight or less of a silane coupling agent or a titanate coupling agent with respect to 100 parts by weight of the curable resin composition. The amount is preferably 0.01 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, but the effect of the present invention can be sufficiently exhibited even when the silane coupling agent or the titanate coupling agent is not included. You can If the silane coupling agent or the titanate coupling agent is contained in an amount of more than 10 parts by weight, the refractive index of the adhesive will decrease.

In the adhesive of the present invention, when the content of the epoxy compound represented by the general formula (I) is 100% by weight and the silane coupling agent or the titanate coupling agent is not contained, Although the adhesive of the invention is composed of the epoxy compound alone, the effect of the invention can be sufficiently exhibited even in this case.

The adhesive of the present invention is usually cured by heat to bond optical materials and electronic materials. When the compound copolymerizable with the epoxy compound is a monomer having an epoxy group or an oligomer having an epoxy group, it can be thermally cured using a cationic polymerization initiator. The cationic polymerization initiator is not particularly limited, and examples thereof include boron trifluoride / diethyl ether complex, boron trifluoride / amine complex, aluminum chloride, titanium tetrachloride, tin tetrachloride, iron (III) chloride,
Lewis acids such as zinc chloride; ammonium salts, sulfonium salts, oxonium salts, phosphonium salts and the like can be mentioned.

When the compound copolymerizable with the epoxy compound is a monomer having a thiol group, a polymer having a thiol group, or an acid anhydride, it can be thermally cured by using a curing accelerator. Examples of the curing accelerator include tertiary amines such as triethylamine, hexamethylenetetramine and tetramethylguanidine;
Examples thereof include imidazoles such as 2-ethyl-4-methylimidazole and 2,4-diethylimidazole; metal salts such as dibutyltin dilaurate, dioctyltin dilaurate and tin octylate.

In the above curing, the curing temperature and the curing time vary depending on the composition of the adhesive of the present invention, the application, the type of the polymerization initiator or curing accelerator used and the amount thereof, and therefore cannot be unconditionally specified. , Curing temperature is 0
The temperature is preferably 200 ° C, more preferably 20 to 150 ° C. The polymerization time is preferably 1 minute to 50 hours, more preferably 1 to 20 hours.

In the present invention, further, if necessary,
Additives such as an aluminum coupling agent, a light stabilizer, an ultraviolet absorber, an antioxidant, a coloring inhibitor, a polymerization inhibitor and a bluing agent can be added. The properties of the adhesive of the present invention can be further modified by adding these additives alone or by mixing them.

[0036]

The present invention will be described in more detail with reference to the following reference examples and examples, but the present invention is not limited to these examples. In addition, the evaluation method of the adhesive obtained by the following examples was as follows.

(1) Refractive index: 20 using an Abbe refractometer (4T type manufactured by Atago Co., Ltd.)
The refractive index of the cured adhesive at ℃ was measured. (2) Light transmittance An adhesive is applied to a glass plate having a refractive index of 1.70 and a thickness of 2 mm, and two sheets are laminated and cured, and then, a turbidity meter (Nippon Denshoku Industries Co., Ltd., NDH-300A type) is used. Was used to measure the light transmittance of the multilayer plate.

(3) Adhesive force (tensile shear adhesive strength of aluminum plate) 100 mm × 25 m according to JIS K 6850
m, 2 mm thick aluminum plate coated with adhesive
2.5 mm pasted and cured, then 20 mm per minute with a tensile tester (Shimadzu Corporation AGS-5KND)
The adhesive strength was evaluated by measuring the tensile shear adhesive strength at a speed of.

(Compressive shear adhesive strength of glass plate) JIS
Referring to K 6852, apply an adhesive to a Pyrex glass plate having a size of 35 mm × 25 mm and a thickness of 5 mm, and
After 0 mm bonding and curing, the adhesiveness was evaluated by measuring the compressive shear bond strength with a tensile tester (Shimadzu Corporation, AGS-5KND) at a speed of 5 mm per minute. (4) Heat resistance The test piece used for the compression shear adhesive strength of the glass plate was further heated at 200 ° C. for 3 hours and the state of the bonded portion was observed.

Reference Example 1 Preparation of Epoxy Compound In a 1 L four-necked flask, 100 g of 4,4-bis (mercaptophenyl) sulfide and 15 epichlorohydrin were added.
0 g and 300 g of dioxane were added, and 20 g of a 10% aqueous potassium hydroxide solution was added dropwise while keeping the temperature at 10 ° C. 20 ° C
After reacting for 2 hours at 60 ° C., the temperature was raised to 60 ° C. and 90 g of a 45% aqueous sodium hydroxide solution was added dropwise. After reacting for 12 hours at 60 ° C., water and toluene were added to separate the layers. After washing this organic layer with water, the solvent was distilled off, and in the general formula (I), R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms and bis [4- (2,3 140 g of -epoxypropylthio) phenyl] sulfide were obtained. Obtained bis [4-
(2,3-Epoxypropylthio) phenyl] sulfide is a colorless transparent liquid, and its refractive index is n ²⁵ _D =
It was 1.669. Epoxy compounds represented by the general formula (I) in which R ¹ , R ² , R ³ and R ⁴ were different were obtained by the same method.

Example 1 100 parts by weight of bis [4- (2,3-epoxypropylthio) phenyl] sulfide obtained in Reference Example 1, 2 parts by weight of γ-glycidoxypropyltrimethoxysilane, a polymerization initiator (SAN AIDE) SI-60L) 2 parts by weight were mixed to prepare an adhesive. The obtained adhesive was cured at 130 ° C. for 4 hours, and the refractive index, light transmittance and adhesiveness were evaluated.
It was shown to.

Examples 2 to 10 Adhesives were prepared in the same manner as in Example 1 using the component compositions shown in Table 1, and their physical properties were evaluated.

Comparative Example 1 1,4-bis (4-methacryloylthio-2-thiabutyl) benzene was used as an epoxy compound, and 18.5 parts by weight of styrene and 1.0 part by weight of glycidyl methacrylate were used as copolymerizable compounds. An adhesive was prepared in the same manner as in Example 1, and the physical properties thereof were evaluated and shown in Table 1.

In Table 1, GPTS is γ-glycidoxypropyltrimethoxysilane, SI-60L is a liquid type cationic polymerization initiator manufactured by Sanshin Chemical Co., Ltd., TAHT.
Is tetra (2,2-dialkyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, SI-60 is a powder type cationic polymerization initiator manufactured by Sanshin Chemical Co., and ELA-115CA is Sumitomo Chemical Co., Ltd. bisphenol A type epoxy resin, MPTS
Is γ-mercaptopropyltrimethoxysilane, B
MEP is 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, PETP is pentaerythritol tetrakisthiopropionate, BT
L is dibutyltin dilaurate, XEMA is 1,
4-bis (4-methacryloylthio-2-thiabutyl)
Benzene, THEI is N, N ′, N ″ -tris (mercaptoethylcarbonyloxyethyl) isocyanurate, TMI is tris (3-mercaptopropyl) isocyanurate, and AIBN is azobisisobutyronitrile. Respectively.

[0045]

[Table 1]

[0046]

Since the adhesive of the present invention has the above-mentioned constitution, it has a high refractive index and a high adhesive strength, and is very suitable as an adhesive used for optical materials, electronic equipment materials and the like.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuya Ikeda 346 Miyanishi, Harima-cho, Kako-gun, Hyogo Pref.

Claims (3)

[Claims] 1. A curable resin composition consisting of 5 to 100% by weight of an epoxy compound represented by the following general formula (I) and 0 to 95% by weight of a compound copolymerizable with the epoxy compound. On the other hand, an adhesive containing 10 parts by weight or less of a silane coupling agent or a titanate coupling agent. Embedded image In the formula, R ¹ , R ² , R ³ and R ⁴ are the same or different,
It represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms. n represents an integer of 0 to 10. 2. The adhesive according to claim 1, wherein R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms. 3. The compound copolymerizable with the epoxy compound is at least selected from the group consisting of a monomer having an epoxy group, an oligomer having an epoxy group, a monomer having a thiol group, and an oligomer having a thiol group. The adhesive according to claim 1, which is one kind.