JPS6253531B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to an epoxy resin composition, which can be used as a sealing material for electronic components, an insulating paint for substrates, an adhesive, etc., and has excellent heat resistance, electrical insulation, adhesion, etc. It is possible to improve the properties of [Conventional technical field] Epoxy resins are made of aliphatic amines, aromatic amines,
It is widely used in various fields because it is cured by adding amines such as polyamide compounds and tertiary amine compounds, or acid anhydrides, etc. to provide resins with excellent heat resistance, electrical insulation, and adhesive properties. In particular, it is known that when a specific imidazole compound is blended with an epoxy resin, a one-component composition with good workability can be obtained, and it also provides a resin with excellent heat resistance. [Problems to be Solved by the Invention] As electronic components become smaller and more dense, these sealing resins are required to have high heat resistance. Similarly, with the increasing density of printed circuits, insulating paints for printed circuit boards are also required to have heat resistance and anti-migration properties for conductors such as silver and copper. Although various functional resins have been put on the market in response to these demands, there are very few that satisfy the requirements in terms of workability or properties. That is, in terms of workability, there were dissatisfaction with the curing conditions and non-one-component property, and in terms of properties, there were dissatisfaction with large curing shrinkage and low adhesion. [Means for Solving the Problems] In view of the above circumstances, the inventors of the present invention have conducted numerous tests and researches, and as a result, they have found that the present inventors have excellent properties such as heat resistance, electrical insulation, adhesion, and anti-migration properties. We have also discovered an epoxy resin composition that can be made into one liquid, has excellent workability, and can be cured at a relatively low temperature, and can be used for electronic component sealing materials, electrical insulation paints, adhesives, and the like. That is, a 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct represented by the following formula and polyvinyl-para-phenol represented by the following formula By blending both of these with an imidazole compound into a general-purpose epoxy resin, or by blending only 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid with an imidazole compound into a general-purpose epoxy resin, the desired result can be obtained. We have discovered an epoxy resin composition that can be used for this purpose. Excellent storage stability was achieved by mixing a certain type of imidazole compound with the epoxy resin. It is well known that one-component formulations are obtained and that they cure at relatively low temperatures, around 150°C. Furthermore, it is also a well-known fact that the cured product has excellent heat resistance, electrical insulation, adhesion, etc., and is widely used as an electronic component sealing material, electrical insulation paint, or adhesive. A feature of the present invention is that a general-purpose epoxy resin is blended with a 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct, polyvinyl-para-phenol, and a certain type of imidazole compound; 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct and the imidazole compound to a general-purpose epoxy resin
The point is that a composition with good properties as described above can be obtained by blending the above-mentioned ingredients. Epoxy resins suitable for carrying out the present invention include polyglycidyl ethers of polyhydric phenols, such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, other epoxidized phenol-novolac resins, and alicyclic epoxy resins. be. Imidazole compounds include 2,4-diamino-6-{2'-methylimidazolyl-(1)'}ethyl-s-triazine, 2,4-diamino-6-
{2′-Methylimidazolyl-(1)′}ethyl-s-triazine-isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2
-Phenyl-4-methyl-5-hydroxymethylimidazole, 4,4'-methylene-bis-(2-
Latent curing agents that exhibit good storage stability and quick curing properties when blended with liquid epoxy resins such as ethyl-5-methylimidazole and 2-phenyl-4-benzyl-5-hydroxymethylimidazole are preferred. 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct can be obtained by a method of reacting biguanide with acrylic acid chloride [J.Am.
Chem.Soc., 80, 988 (1958)], a method for reacting dicyandiamide with β-dimethylamino-propionitrile (French Patent No. 1563255), and 1,2-di{4,6'-diamino-s- 2-vinyl-4,6-diamino-s-triazine produced by a method such as heating triazinyl-(2)′}-cyclobutane under reduced pressure (Japanese Patent Publication No. 46-35068) and isocyanuric acid are mixed in water. It is synthesized by heating in the presence of a polymerization inhibitor. The appropriate amount of the 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct to be added is 5 to 40 parts by weight per 100 parts by weight of the epoxy resin. Although the curing mechanism of the composition of the present invention is not clear,
It can be considered as follows. That is, epoxy resin is anionically polymerized by the action of the imidazole compound 2,4-diamino-6-{2'-methylimidazolyl-(1)'}ethyl-s-triazine [J. Appl. Polym. Sci., 12 ,159
(1968)]. At the same time, the double bond of the 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct is cleaved and undergoes radical polymerization. Furthermore, the two amino groups of the triazine ring also undergo an addition reaction with the epoxy resin due to the presence of the imidazole compound. It is thought that the three types of reactions occur almost simultaneously in this way, resulting in a cured product with excellent mechanical and electrical properties when heated. Next, an epoxy resin composition prepared by mixing an epoxy resin with a 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct, an imidazole compound, and polyvinyl-para-phenol will be described. A so-called thick-film hybrid integrated circuit board made by forming a desired circuit such as a silver, platinum, or palladium-based conductor, resistor, or capacitor using glass frit as a binder on an insulating substrate such as ceramics or glass by screen printing and firing at high temperature. Or paper-
In printed circuit boards, in which the desired circuit is formed by etching copper foil onto a phenolic resin or glass-epoxy resin laminate, the required circuit is usually exposed flat on the surface, so it is susceptible to corrosive effects in the atmosphere. There is a risk that the circuit parts may be corroded due to adhesion of substances or moisture. In order to prevent accidents caused by such corrosion and further improve the reliability of the circuit, a method is generally used and practiced in which a protective coating called a permanent resist is formed on the circuit by screen printing or the like. In this case, the protective coating film is required to have various properties such as electrical insulation, moisture resistance, chemical resistance, adhesion, and hardness.
Furthermore, the circuits of the thick film hybrid integrated circuit boards and printed circuit boards tend to be minute and complicated, and when plating with nickel, gold, copper, solder, etc., there is a risk of short circuits due to the plating. In order to prevent accidents caused by this, a method is known in which a protective coating called resist ink is applied by screen printing to areas other than those that require plating, and after curing to form a coating film, plating is applied only to the necessary areas. The protective coating is required to have ink functions such as viscosity suitable for screen printing, stringiness, and thixotropic properties. high temperature,
Discoloration and migration of silver and copper conductor circuits that occur when voltage is applied under high-humidity environmental conditions are caused by the miniaturization of printed circuit boards, This has become a problem as more advanced requirements such as higher density and higher reliability are required. However, triazine resin, bis-maleimide
Except for triazine resin alone or in combination with other resins, there are almost no useful protective coatings. Traditionally, protective coatings with the above-mentioned properties and functions include baking-type glass-based, heat-curing epoxy resin-based, phenol resin-based, melamine resin-based, epoxy-melamine resin-based, silicone resin-based, and Shibagai wire-curing type. Paints based on epoxy-acrylate resins are known, but with the exception of glass-based paints, they are insufficient in preventing discoloration and migration of silver and copper conductors. The triazine resin system and bis-maleimide-triazine resin system also have problems in curing conditions, pot life, etc., and are not satisfactory. However, the aforementioned epoxy resin, imidazole compound, 2-vinyl-4,6-diamino-s
- An epoxy resin composition consisting of a triazine-isocyanuric acid adduct with an average degree of polymerization of 25 to 70 and a particle size.
200 to 300 mesh of polyvinyl paraphenol to 100 to 40 parts by weight of epoxy resin
It has been found that the above defects can be overcome by uniformly dispersing and blending 20 to 100 parts by weight of the filler. This is a one-component epoxy resin composition with good storage stability, and can be used as a protective coating for thick-film hybrid integrated circuit boards, printed circuit boards, etc., or as an insulating layer for multiple wiring. In the composition of the present invention, a coloring pigment may be added as necessary, and it is also possible to add a thixotropy imparting agent, an antifoaming agent, or a surface fluidity modifier to impart screen printing suitability. . By adding polyvinyl para-phenol, quick curing properties and adhesion to the substrate can be improved. Example 1 Diglycidyl ether type liquid epoxy resin of bisphenol A (trade name Epicote #828, manufactured by Yuka Ciel Epoxy), 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct,
2,4-diamino-6-{2'-methylimidazolyl-(1)'}ethyl-s-triazine and fluidity regulator Aerosil #300 (manufactured by Nippon Aerosil) were mixed in the proportions shown in Table 1, and three bottles were prepared. The mixture was uniformly kneaded using a roll mill and defoamed under a reduced pressure of 5 mmHg. The results of measuring the compound properties and cured product properties of the epoxy resin composition thus produced are shown in Table 1.

[Table] Examples 2 to 6 The constituent substances shown in Table 2 were blended in predetermined proportions and treated in the same manner as in Example 1 to produce epoxy resin compositions, and the properties of the blend and cured product were measured. . Table 3 shows the results of these tests.

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Claims (1)

[Claims] 1. At least epoxy resin, 2-vinyl-4,
An epoxy resin composition comprising three essential components: a 6-diamino-s-triazine-isocyanuric acid adduct and an imidazole compound. 2 At least epoxy resin, 2-vinyl-4,
An epoxy resin composition containing four essential components: a 6-diamino-s-triazine-isocyanuric acid adduct, an imidazole compound, and polyvinyl-para-phenol.