JPH0491183A - Thermosetting filmy adhesive - Google Patents

Abstract

PURPOSE:To provide the title adhesive of high storage stability, excellent in adherability over a wide temperature range, produced from a mixture comprising a reactive elastomer, epoxy resin, solvent, epoxy compound of imidazole derivative and non-reactive diluent. CONSTITUTION:The objective adhesive produced from a mixture comprising (A) a reactive elastomer (e.g. carboxyl group-contg. styrenebutadiene copolymer), (B) an epoxy resin (pref. bisphenol A-type epoxy resin), (C) a solvent soluble for these components A and B (e.g. toluene), (D) an epoxy compound of imidazole derivative (e.g. an adduct of e.g. imidazole and e.g. bisphenol A-type epoxy resin), and (E) a non-reactive diluent (pref. dioctyl phthalate).

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention has particularly excellent storage stability and adhesive strength over a wide temperature range, and is capable of being peeled off by heating the connected parts to a predetermined temperature or higher. The present invention relates to possible film adhesives.

(Prior Art) As electronic devices have become smaller and thinner in recent years, there has been an increasing need to temporarily bond components when fixing microcomponents or connecting microcircuits. That is, while it is necessary to firmly adhere and fix the material, it is also required to be able to be removed as necessary without damaging or damaging the material.

Conventionally, such film adhesives can be broadly classified into thermoplastic types and thermosetting types, and recently, epoxy resin-based thermosetting types, which have excellent reliability, have been widely used. However, many of these are two-component, have poor storage stability, or those with excellent storage stability require a long time or high temperature to cure, while those that can be cured at low temperatures and in a short time have poor storage stability. There were problems such as inferiority etc.

In order to solve these problems, we developed adducts made by reacting imidazole derivatives and amine derivatives with epoxy resins,
Furthermore, curing agents containing these microencapsulated materials are commercially available. However, all of these have poor solvent resistance, and there are major restrictions when using solvents. If a solvent is used, the types of solvents that can be used for film formation are not only limited, but also the workability is such that the film must be formed within a short time after mixing and adjustment, and the solvent must be removed quickly. There is a problem.

In addition, as mentioned above, there are many requests to peel off the connected parts without damaging or damaging the connected parts, and most of the thermosetting types have advantages such as high adhesive strength and high reliability. On the other hand, there is a problem that it cannot be adapted to such demands.

(Problem to be solved by the invention) When producing a thermosetting film adhesive, a film forming agent is applied and other compounds for improving various properties are dissolved and mixed in a solvent to form a film. Alternatively, when using a commercially available microencapsulated curing agent or amine adduct that can be cured at low temperatures and in a short time as described above, polar solvents cannot be used.

Further, it is impossible to use a thermosetting resin such as an epoxy resin alone to meet the requirement of peeling off a connected member without damaging or damaging the connected member. In order to provide performance that can meet these demands, it is necessary to mix a reactive thermoplastic elastomer or use a solvent for this purpose.

The present invention solves these conflicting problems, and has excellent storage stability and adhesive strength over a wide temperature range (-30 to 100°C), and also allows for -temperature connections to be heated to a predetermined temperature or higher. The object of the present invention is to provide a thermosetting film adhesive that can be peeled off by heating.

(Means for Solving the Problems) The present invention provides a reactive elastomer, an epoxy resin, a solvent for dissolving these, an imidazole derivative Evoquin compound,
and a non-reactive diluent.

The reactive elastomers used in the present invention include a carboxyl group-containing styrene-butanoene copolymer, a carboxyl group-containing styrene-isoprene copolymer, a carboxyl group-containing styrene-butanoene saturated copolymer, and a carboxyl group-containing styrene-butanoene copolymer. -isoprene saturated copolymer, carboxyl group-containing styrene-ethylene-butene-styrene copolymer, carpoquinyl group-containing styrene-ethylene-butene-styrene saturated copolymer, carboxylic acid-terminated acrylonitrile-dashiene copolymer, carboxylic acid Modified acrylonitrile loop dashiene copolymer, hydrogenated carboxylic acid modified acrylonitrile loop dashiene copolymer, carboxylic acid modified acrylic rubber, butyral resin, urethane resin, amino group modified polyol resin, amino group modified phenoxy resin, hydroxy terminal Examples include saturated copolymerized polyester resin and carboxyl-terminated saturated copolymerized polyester resin. Preferably, it is a carboxyl group-containing styrene-ethylene-butene-styrene saturated copolymer.

Further, the epoxy resin used in the present invention is an epoxy resin having at least two or more epoxy groups in the molecule. Specific examples include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, dimer acid diglysodyl ester, phthalate diglysodyl ester, and tetrabrome. Examples include bisphenol A diglycidyl ether, bisphenol hexafluoroacetone diglycidyl ether, triglycidyl isocyanurate, and tetraglycidyl diaminodiphenylmethane, which may be used alone or in combination of two or more. Preferably it is a bisphenol A type epoxy resin.

Any solvent can be used as long as it completely dissolves the above-mentioned reactive elastomer and epoxy resin. Specific examples include acetone, methyl ethyl ketone,
Methyl isobutyl ketone, benzene, toluene, xylene, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, ethyl acetate, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, diacetone ether, methyl cellosolve acetate, ethyl cellosolve acetate, dimethyl formamide, Examples include dimethylacetamide, which can be used alone or in combination of two or more.

The imidazole derivative epoxy compound is an adduct of an imidazole compound and an epoxy compound. The imidazole compounds include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-
Methylimidazole, 2-phenylimidazole, 2-
Phenyl-4methylimidazole, 1-hensyl-2-
Methylimidabul, l-benzyl-2-ethylimidazole, 1-hensyl-2-ethyl-5-methylimidazole, 2-phenyl-4-methyl-5hydroxymethylimidazole, 2-phenyl4.5-dihydroquinemethyl Examples include imidazole. Examples of epoxy compounds include glycidyl ether type epochino resins such as hisphenol A, phenol novolac, bisphenol F, and brominated hisphenol A, dimic acid diglyndyl ester, and phthalic acid diglyndyl ester. . Preferably, it is a hisphenol A type epochino resin.

The reaction product of the above-mentioned imidazole derivative and epoxy compound is commercially available as a fine powder.

Furthermore, there are also those that have been mixed with isocyanate compounds to improve storage stability, and those that have been microencapsulated. Among these, it is preferable to use microcapsules. However, as mentioned above, these have poor solvent resistance. These drawbacks can be easily improved by mixing 5 to 30% of a non-reactive diluent to the reaction product of the imidazole derivative and the epoxy compound.

As a result, when producing a thermosetting film adhesive, it is possible to apply a film forming material and to form a film by dissolving and mixing compounds in a solvent to improve various properties. Commercially available microencapsulated curing agents and amine adducts that can be cured at low temperatures and in short periods of time can also be used in formulations prepared using polar solvents as curing agents. If the amount of non-reactive diluent used is less than 5%, it will have a poor effect on storage stability, and if it is more than 30%, the physical properties of the cured product, such as adhesive strength and degree of curing, will be significantly impaired.

Furthermore, when a reactive diluent was used, no effect on storage stability was observed.

Examples of non-reactive diluents include phthalate esters such as dibutyl phthalate, dioctyl phthalate, hebutylnonyl phthalate, ditridecyl phthalate, diethyl phthalate, dimethyl phthalate, butylbenzyl phthalate, tributyl phosphate, and phosphorus. Examples include phosphoric acid esters such as diphenyl acid and diphenyl monocresyl phosphate, and fatty acid esters such as butyl stearate, methoxyethyl oleate, and glycerin triheptanoate. Preferably it is dioctyl phthalate.

Hereinafter, the present invention will be specifically explained with reference to Examples.

(Example 1) As a reactive elastomer, a carpoxyl group-containing styrene-ethylene-butene-styrene saturated copolymer "Toughtic M 19] 3J (manufactured by Asahi Kasei Corporation) was used, and MEK (
It was dissolved in a mixed solvent (12) of (methyl ethyl ketone) and toluene to prepare a 50% solution. Add 60 parts by weight of this solution to hisphenol Δ type epoxy resin "Epicoat 82".
50 parts by weight of 8J (manufactured by Yuka Ciel Evokin Co., Ltd.) were mixed. Apart from this, the epoxy resin "Epicoat 1004J"
(Manufactured by Yuka Shell Evokin Co., Ltd.) 100 parts by weight was added to MEK.
It was dissolved in 50 parts by weight, added to the above reactive elastomer solution, and mixed uniformly. To this mixed solution, 12.5 parts by weight of dioctyl phthalate was added as a non-reactive diluent, and as a reaction product of an imidazole derivative and an epoxy compound,
500 parts by weight of HX 3742 (manufactured by Asahi Kasei Corporation) was mixed.

Use this as a release film (polyethylene terephthalate)
Apply it to a thickness of 15 μm after drying, and apply it at 50°.
After drying at C for 1 hour, it was peeled off from the release film to obtain a film adhesive.

(Example 2) Furthermore, in order to examine the characteristics when using a solvent with increased polarity, a calhochytyl group-containing 7. Styrene-ethylene-butene-styrene saturated copolymer “Toughtic M19” 3J
30 parts by weight, DMF (dimethylformamide) 30
parts by weight, and in the same manner as in Example 1, an epoxy resin, a non-reactive diluent, and a reaction product of an imidazole derivative and an epoxy compound were mixed, applied, and dried to obtain a film adhesive. Ta.

(Example 3) As a reaction product of an imidazole derivative and an epoxy compound, a powder obtained by reacting a glynodyl ether type epoxy resin to bisphenol with 2-methyl imidabul was pulverized to a particle size of 5 μm or less. A film adhesive was obtained in the same manner as in Example 2, except that 10 parts by weight of the adhesive was used.

(Example 4) As a reactive elastomer, carboxylic acid-modified acrylonitrile loop dashiene copolymer (manufactured by Nippon Gosei Rubber Co., Ltd.) 30
A film adhesive was obtained in the same manner as in Example 1, except that part by weight was dissolved in a mixed solvent of 30 parts by weight of DMF and 5 parts by weight of MEK.

(Comparative Example 1) A film-like adhesive was formed in the same manner as in Example N1 except that aliphatic diglycidyl ether was used as a reactive diluent instead of a non-reactive diluent, but the storage stability was very high. It was bad.

(Comparative Example 2) Example 1 except that 2 g of dioctyl phthalate was used so that the amount of the non-reactive diluent was 5% or less with respect to the reaction product of the imidazole derivative and the epoxy compound. A film adhesive was formed in the same manner as above, but this adhesive also had very poor storage stability.

(Comparative Example 3) Example 3 except that 17.5 g of dioctyl phthalate was used so that the amount of the non-reactive diluent was 3506 with respect to the reaction product of the imidazole derivative and the epoxy compound. A film-like adhesive was formed in the same manner, and although it had excellent storage stability, it had poor adhesive strength and connection reliability.

The film adhesives obtained in these Examples and Comparative Examples were tested for storage stability, adhesive strength, and repairability, and the results are shown in Table 1.

The adhesion strength was tested using a 90' Beer test, and the adherend was 50' with a nickel plating of 5 μm.
μm M@ and a glass epoxy laminate were used.

Repairability was evaluated by heating a test piece connected by non-pressure bonding to 165°C and peeling it off, and observing whether the connected member could be peeled off without damage.

To evaluate storage stability, after leaving it at room temperature and 40'C for one month, it was confirmed that it melted on a 120°C hot plate.
Furthermore, it was confirmed whether the above-mentioned adherend could be bonded under predetermined conditions, and the adhesive force was measured. If the value was 95% or more of the initial value, it was evaluated as ○.

(Effects of the Invention) As described above, according to the present invention, when producing a thermosetting film adhesive, a film-forming agent can be applied, etc., without being restricted by the type of solvent. It is possible to form a film by dissolving and mixing compounds to achieve performance. In addition, it can be bonded in a short time, has excellent storage stability and adhesive strength over a wide range of temperatures (-30 to 100°C), and can be peeled off by heating the connected item to a specified temperature or higher. It is possible to provide a thermosetting film adhesive having the following properties.

Claims (1)

[Claims] (1) A film adhesive characterized by being formed from a mixture containing a reactive elastomer, an epoxy resin, a solvent for dissolving these, an imidazole derivative epoxy compound, and a non-reactive diluent.