JPS6242929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for curing an epoxy compound having an average of more than one epoxy group in the molecule, and its purpose is to cure a polyepoxy compound monomer and a curing agent in a mixture. To provide a system that has a long pot life at room temperature, can be used as a one-component epoxy resin that hardens rapidly when heated to a desired temperature during curing, and provides excellent heat resistance to the cured resin. It is in.

The method of the present invention can be applied to electronic component encapsulating materials, insulating materials, adhesives, etc. and exhibits remarkable effects.

When curing a polyepoxy compound, it is known that blending an imidazole compound results in a one-component composition that is easy to work with and provides a resin with considerable heat resistance. With the miniaturization and increase in density, there is a demand for further improvements in workability, heat resistance, etc.

In view of this situation, the inventors of the present invention have conducted intensive studies aimed at creating a one-component epoxy resin with high heat resistance. As a result, the present inventors have developed a polyepoxy compound having an average of more than one epoxy group in the molecule as a curing agent. 2,4-diamino-6{2'-alkylimidazolyl(1)'}ethyl-S-triazine formula shown by the following formula (However, in the formula, R is an alkyl group, R' is a hydrogen atom or an alkyl group) or 2,4-diamino-6- represented by the following formula
{2′-alkylimidazolyl(1)′}ethyl-S-triazine isocyanuric acid adduct Formula (However, R and R' in the formula are the same as above), 2,4-diamino-6-vinyl-S-triazine, and a polymerization initiator for the polymerizable monomer are mixed and heated to achieve the desired purpose. This has been achieved.

The reason why the cured epoxy resin product produced by the method of the present invention has excellent heat resistance is that when the polyepoxy compound and imidazole compound are heated, they undergo anionic polymerization to create a three-dimensional network structure.
Furthermore, when vinyl triazine is heated in the presence of a polymerization initiator, it radically polymerizes and becomes a highly heat-resistant linear polymer. The rigid chains of S-triazine intersect to form IPN (Inter
This is thought to be due to the formation of a (penetrated network) structure.

The use of a specific imidazole compound in the method of the present invention is essential in order to achieve both the pot life and workability such as fluidity of the one-component composition and the heat resistance of the resin.

The curing agent 2,4-diamino-6-{2'-alkylimidazolyl(1)'}ethyl-S-triazine used in the present invention is synthesized by the method described in Japanese Patent Publication No. 47-36391. The typical one is 2,4-diamino-6-{2′-
Methylimidazolyl(1)'}Ethyl-S-triazine, 2,4-diamino-6-{2'-ethyl4'-methylimidazolyl(1)'}Ethyl-S-triazine, 2,4-diamino-6- {2′-undecylimidazolyl(1)′}ethyl-S-triazine, etc., and curing agent 2,4-diamino-6-{2′-alkylimidazolyl(1)′}ethyl-S-triazine isocyanurate. Acid adducts are designated as Special Publication No. 56-39314.
2,4-diamino-6-
{2'-Methylimidazolyl (1)'} Ethyl-S-triazine isocyanuric acid adduct, 2,4-diamino-6-{2'-ethyl-4'-methylimidazolyl
(1)'} Ethyl-S-triazine isocyanuric acid adduct, etc. The appropriate amount of these curing agents to be used is 3 to 10 parts by weight per 100 parts by weight of the polyepoxy compound. Also, the polymerizable monomer 2,4
-Diamino-6-vinyl-S-triazine can be blended in an amount of 5 to 100 mol% based on the polyepoxy compound.

Polymerization initiators for 2,4-diamino-6-vinyl-S-triazine include generally known organic peroxides, inorganic peroxides, azoisobutylnitrile, etc. Among these, those that change less over time Dicumyl peroxide is particularly suitable because it is easy to handle.

The amount of polymerization initiator used is 2,4-diamino-6
-Vinyl-S-triazine 0.5 to 1.0% is suitable.

In carrying out the present invention, inorganic fillers such as calcium carbonate, talc, alumina, and silica, and coloring agents such as pigments and dyes may be added in addition to the above-mentioned main components.

In the method of the present invention, in addition to forming a one-component composition in which each component is uniformly mixed in advance, it is also possible to mix a curing agent or a polymerization initiator immediately before the reaction. The curing reaction can be completed by heating to a temperature of about 90-150°C for several hours.

The present invention will be specifically explained below with reference to Examples and Reference Examples.

Example 1 Diglycidyl ether of bisphenol A [trade name "Epomic R-140" (Mitsui Petrochemical Epoxy) 100 g, 2,4-diamino-6-{2'-methylimidazolyl(1)'}ethyl-S- triazine 5
g, 3.15 g of 2,4-diamino-6-vinyl-S-triazine, 0.1 g of dicumyl peroxide [trade name "Bark Mill D-40" (NOF)] (0.5% molar ratio to vinyl triazine), and viscosity adjustment Agent [Product name: “Erosil #300” (Japan Aerosil)
1 g was uniformly dispersed and mixed using a three-roll mill to form an epoxy resin composition.

The viscosity of this product at 25°C is 3200 cps, the viscosity increase rate when left at 40°C for one week is 22%, and the gel time when heated at 150°C is 2 minutes 10 seconds; The cured product after 4 hours at 150°C has a glass transition point of 166°C.
The heat distortion temperature (JISK-7207) was 161℃, and the bending strength (JISK-7203) was 7.7Kg/ ^mm2 at 25℃.

Reference example In the above example, 2,4-diamino-6-
A similar treatment without the addition of vinyl-S-triazine and dicumyl peroxide resulted in an uncured epoxy resin composition with a viscosity of 3,100 cps.
(25℃) The viscosity increase rate is 17%, the gel time is 2 minutes 35 seconds, and the cured product has a glass transition point of 124℃, a heat distortion temperature of 131℃, and a bending strength of 7.4Kg/mm ² (25℃), 0.7
Kg/mm ² (150°C).

Example 2 In Example 1, the curing agent 2,4-diamino-
6-{2′-methylimidazolyl(1)′}ethyl-S
- Treated with exactly the same formulation except that triazine was changed to 2,4-diamino-6-{2'-methylimidazolyl(1)'}ethyl-S-triazine isocyanuric acid adduct (the amount used was the same), In addition, when various properties were investigated under the same conditions, the uncured epoxy resin composition had a viscosity of 3500 cps (25°C), a viscosity increase rate of 5%,
The gel time is 1 minute 20 seconds, and the cured product has a glass transition point of 170℃, a heat distortion temperature of 166℃, and a bending strength of 9.7.
Kg/mm ² (25°C) and 2.1Kg/mm ² (150°C).

Claims (1)

[Claims] 1 A polyepoxy compound having an average of more than one epoxy group in the molecule, 2,
4-diamino-6-{2'-alkylimidazolyl
(1)'} Ethyl-s-triazine or 2,4-diamino-6-{2'-alkylimidazolyl (1)'} Ethyl-s-triazine isocyanuric acid adduct from 3 to 10% per 100 parts by weight of the polyepoxy compound. Part by weight, 2,4-diamino-6 as a polymerizable monomer
- A method for curing an epoxy resin, which comprises mixing 5 to 100 mol% of vinyl-s-triazine with respect to a polyepoxy compound and a polymerization initiator for the polymerizable monomer and heating the mixture.