JPH05306384A - Thermosetting tacky adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a composition excellent in humidity resistance, heat resistance and tackiness and useful as a adherend, etc., of metals, papers, plastics, etc., by blending a specific epoxy resin with an epoxy resin curing agent. CONSTITUTION:The composition is obtained by blending (A) 100 pts.wt. epoxy resin containing 5-85 pts.wt. naphthol based epoxy resin of formula I [A and B are formula II or formula III (R) is H or 1-6C hydrocarbon; R2 and R3 are H or methyl); G is glycidyl; (l), (m) and (n) are 0-10; (p) is l or 2, with the proviso that (l) and (n) are not simultaneously 0] with (B) one or more kinds of epoxy resin curing agents selected from dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermosetting adhesive / adhesive composition which is cured by heating.

[0002]

2. Description of the Related Art Conventionally, a cured product of an epoxy resin is used as a thermosetting adhesive because it has excellent heat resistance and forms a strong cured product. As the thermosetting adhesive / adhesive composition based on epoxy resin, those mainly using bisphenol A type epoxy resin are widely used.

For example, Japanese Patent Publication No. 47-43615 discloses a thermosetting adhesive composition in which a bisphenol A type epoxy resin is mixed with a thermoplastic polymer and an epoxy resin curing agent. Further, Japanese Patent Publication No. 47-47291 discloses an adhesive composition in which an unsaturated ester resin obtained by modifying a bisphenol A type epoxy resin with an unsaturated basic acid and a thermoplastic resin are mixed.

However, thermosetting adhesives have come to be used in fields requiring high performance such as the automobile industry, electric and electronic industries, and aerospace fields, and further heat resistance and moisture resistance are strongly demanded. Has been done.

Therefore, epoxy resins other than the bisphenol A type epoxy resin have been studied as adhesives. The present inventors have already proposed a novel naphthol-based epoxy resin in Japanese Patent Laid-Open No. 3-90075. The present invention was made by studying such a naphthol-based epoxy resin as a base for a thermosetting adhesive.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tacky adhesive composition excellent in moisture resistance and heat resistance for bonding metals, plastics, wood, paper, etc. The present invention is to provide a thermosetting pressure-sensitive adhesive composition which is tacky and hardens by heating.

[0007]

Means for Solving the Problems That is, the present invention provides a thermosetting adhesive and pressure-sensitive adhesive composition containing an epoxy resin and an epoxy resin curing agent, in 100 parts by weight of the epoxy resin, the following general formula (1):

[Chemical 2] The thermosetting adhesive composition is characterized in that 5 to 85 parts by weight of a naphthol-based epoxy resin is blended.

The naphthol-based epoxy resin represented by the above general formula (1) is obtained by adding p-naphthols such as 1-naphthol, 2-naphthol and naphthalenediols.
Xylylene glycol, 1,4-di (2-hydroxy-
Aromatic diols such as 2-ethyl) benzene or their dialkyl ethers, or formaldehyde,
It is synthesized by subjecting a compound obtained by a condensation reaction with a condensing agent such as aldehydes such as acetaldehyde and benzaldehyde to an epoxidation reaction with epihalohydrins such as epichlorohydrin. As these naphthol-based epoxy resins, those which are liquid or viscous at room temperature to those having a softening point of 120 ° C. are preferably used.

In the adhesive composition of the present invention, a well-known epoxy resin having two or more epoxy groups in the molecule is used in addition to the naphthol type epoxy resin. For example,
Bivalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone and resorcin, or tris- (4-
From trivalent or higher phenols such as hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolac, o-cresol novolac, or halogenated bisphenols such as tetrabromobisphenol A Although there are glycidyl ether compounds that are derived, those that are liquid or viscous at room temperature are preferable. These epoxy resins can be used alone or in combination of two or more, and the amount of the naphthol-based epoxy resin represented by the general formula (1) is 5 to 85 parts by weight based on 100 parts by weight of the epoxy resin component. The range is. If it is less than this range, the moisture resistance is lowered, and if it is more than this range, the viscosity is increased and the workability is lowered. It is more preferably in the range of 20 to 50 parts by weight.

As the curing agent used in the resin composition of the present invention, all those generally known as curing agents for epoxy resins can be used. Examples include dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines. To give a concrete example, the polyphenols include phenol novolac, cresol novolac,
There are polyvinylphenol and the like, and as the acid anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride,
Examples thereof include nadic acid anhydride and trimellitic acid anhydride. Also,
As amines, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4 '
There are aromatic amines such as diaminodiphenyl sulfone, m-phenylenediamine and p-xylylenediamine, and aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine and triethylenetetramine. The resin composition of the present invention may be used alone or in combination of two or more.

If desired, a resin such as synthetic rubber may be blended with the resin composition of the present invention. Synthetic rubbers that can be used include butadiene rubber and silicon rubber. Acrylonitrile-butadiene copolymer is preferably used. In addition, carboxyl group-containing polydimethylsiloxanes and the like are blended as the case may be. The compounding amount of the synthetic rubber is in the range of 50 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin component. In addition, these synthetic rubbers may be used to modify the epoxy resin in advance and then added to the adhesive composition of the present invention. By blending a resin such as synthetic rubber, flexibility can be imparted to the adhesive composition of the present invention.

The thermosetting adhesive / adhesive composition of the present invention is optionally used by being laminated on a support sheet such as paper, a plastic sheet, and a metal foil.

[0013]

EXAMPLES The present invention will be described in more detail below by showing Examples of the present invention. (Synthesis of Naphthol Epoxy Resin A) Reference Example 1 In a 300 ml four-necked flask, 144 g of 2-naphthol was added.
(1.0 mol), p-xylylene glycol 55.2 g
(0.4 mol) and 14 g of oxalic acid were charged and reacted at 150 ° C. for 3 hours while stirring under a nitrogen stream. During this time, water produced was removed from the system. Then, the temperature was raised to 180 ° C., and the mixture was heated with stirring for 2 hours to decompose oxalic acid.
Further, it was cooled to 140 ° C. and 6.3 g of 92% paraformaldehyde was added. After reacting for 1 hour, volatile components in the system were removed under reduced pressure to obtain 185 g of a brown resin.

100 g of the above resin was added to epichlorohydrin 4
Dissolve in 100 g, add 0.3 g of triethylammonium chloride, and add 70% under reduced pressure (about 150 mmHg).
At 48 ° C., 42 g of 48% aqueous sodium hydroxide solution was added dropwise over 3 hours. During this time, water was removed from the system by azeotropic distillation with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropping was completed, the reaction was continued for another 30 minutes. Then, the salt produced by filtration is removed, and after further washing with water, the epichlorohydrin is distilled off to obtain the epoxy resin 1
12 g was obtained. The epoxy equivalent was 265 and the softening point was 86 ° C.

(Synthesis of Naphthol Epoxy Resin B) Reference Example 2 In a 500 ml four-necked flask, 160 g (1.0 mol) of 1,6-naphthalenediol and 69.0 g (0.5 mol) of p-xylylene glycol were added. And 1.6 g of oxalic acid were charged and reacted at 150 ° C. for 3 hours while stirring under a nitrogen stream. During this time, water produced was removed outside the system to obtain 203 g of a brown resin. Thereafter, an epoxidation reaction was performed using epichlorohydrin in the same manner as in Reference Example 1 to obtain an epoxy resin 1
29 g were obtained. The epoxy equivalent was 188 and the softening point was 79 ° C.

Examples 1 to 4 and Comparative Example 1 With the formulation shown in Table 1, an epoxy resin (naphthol type epoxy resin and / or Epicoat 828 (manufactured by Shell Chemical Co., bisphenol A type epoxy resin)), synthetic rubber ( Nipol 1001 (Nippon Zeon Co., Ltd., acrylonitrile-butadiene rubber)), dicyandiamide,
By mixing 2-methylimidazole (2MZ) and methyl ethyl ketone (MEK), a thermosetting pressure-sensitive adhesive composition was obtained. This composition was applied on a support and then dried to obtain a thermosetting adhesive and pressure-sensitive adhesive tape. The adhesive tape thus obtained is cut into a piece having a width of 25 mm and a length of 150 mm, and the piece is attached to a support of the same size not coated with the adhesive, and then heat-cured at 160 ° C. for 30 minutes to give a test piece. Prepared. Existence of deviation of the adhesive part when a 30 g weight was hung at 140 ° C for 30 minutes at one end of the test piece after exposing this test piece and this test piece to the conditions of 50 ° C and 90% RH for 14 days I checked. The test results are shown in Table 1.

[0017]

[Table 1]

Example 5 Epoxy resin (naphthol type epoxy resin and YDF170 (manufactured by Toto Kasei Co., Ltd., bisphenol F type epoxy resin)), synthetic rubber (Nipol 1001 (manufactured by Nippon Zeon Co., Ltd.) were blended according to the formulation shown in Table 2. , Acrylonitrile-butadiene rubber)), dicyandiamide, 2-methylimidazole (2MZ) and methyl ethyl ketone (MEK).
Was mixed to form a thermosetting adhesive composition, and then a test piece was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0019]

[Table 1]

[0020]

Industrial Applicability According to the present invention, a thermosetting adhesive / adhesive having excellent adhesiveness to moisture, heat resistance and adherends such as metal, paper and plastic can be obtained.

Claims (4)

[Claims] 1. A thermosetting adhesive and pressure-sensitive adhesive composition containing an epoxy resin and an epoxy resin curing agent, wherein the following general formula (1): A thermosetting adhesive / adhesive composition, characterized in that 5 to 85 parts by weight of a naphthol-based epoxy resin is blended. 2. The thermosetting resin according to claim 1, wherein, as the epoxy resin, in addition to the naphthol-based epoxy resin, at least one selected from the epoxy resins having two or more epoxy groups in the molecule is blended. Adhesive composition. 3. The epoxy resin other than the naphthol-based epoxy resin is bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-
Biphenol, 2,2'-biphenol, hydroquinone, resorcin, tris- (4-hydroxyphenyl)
At least one selected from methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolac, o-cresol novolac, and glycidyl ether compound derived from tetrabromobisphenol A. The thermosetting adhesive / adhesive composition according to claim 2. 4. The thermosetting resin composition according to claim 1, wherein the epoxy resin curing agent is at least one selected from dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines. Adhesive composition.