JPH0641503B2 - Curable epoxy resin composition - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to a curable epoxy resin composition used for producing an electric laminate such as a printed wiring board.

[Prior art]

For electric laminates that are processed into printed wiring boards, etc., a prepreg is created by impregnating a base material such as glass cloth with a resin such as epoxy resin and drying, and stacking a plurality of prepregs and copper if necessary. It is manufactured by stacking metal foils such as foils and heat-pressing them. Various attempts have been made to improve the heat resistance of the laminate, and it has been considered to improve the heat resistance of the laminate by increasing the heat resistance of the epoxy resin forming the laminate.

[Problems to be Solved by the Invention]

As an epoxy resin having improved heat resistance, a brominated bisphenol A type epoxy resin has been put into practical use, but the improvement in heat resistance has not yet been achieved. The present invention has been made in view of the above points, and an object of the present invention is to provide a curable epoxy resin composition having excellent heat resistance as a whole.

[Means for Solving the Problems]

The curable epoxy resin composition according to the present invention has the general formula At least one epoxy resin represented by: and tetrabromobisphenol A; Is a main component, and the compounding ratio of the epoxy resin and tetrabromobisphenol A is 1: 1 to 1: 0.7 in terms of an equivalent ratio of glycidyl ether groups and phenolic OH groups. . Hereinafter, the present invention will be described in detail. The epoxy resin used in the present invention is an epoxy resin obtained by converting a condensed novolak of hydroxybiphenyl ether represented by the above formula (I) and hydroxybenzaldehyde into a glycidyl ether, and is a polyfunctional epoxy resin containing 4 or more glycidyl ether groups. is there. In the present invention, these epoxy resins may be used alone or in combination of two or more. Then, the curable epoxy resin composition according to the present invention can be obtained by using this epoxy resin and tetrabromobisphenol A (abbreviated as TBBA) as main components. The epoxy resin and TBBA are used by dissolving each in a solvent of 0 to 50% by weight based on the total weight, and after being dissolved, the epoxy resin and TBBA are reacted by heating at 50 to 150 ° C. TBBA
The phenolic OH group reacts with and is added to the glycidyl ether group of the epoxy resin, so that the heat resistance of the epoxy resin can be increased. Ketones and cellosolves are preferably used as the solvent, and dimethylformamide (DMF) and dimethylacetamide (DMAc) are not suitable for use. The compounding ratio of TBBA to epoxy resin is such that the glycidyl ether group of the epoxy resin and the phenolic O of TBBA
The equivalent ratio with the H group is set in the range of 1: 1 to 1: 0.7. If the blending ratio of TBBA is less than 0.7, the components of TBBA may be insufficient, and the heat resistance may decrease in the glass transition temperature or the heat resistance of the oven, and if the blending ratio of TBBA exceeds 1, TBBA will be excessive. Therefore, there is a possibility that the amount of phenolic OH groups is excessive, the hygroscopicity is deteriorated, and the heat resistance is rather deteriorated. Further, in order to accelerate the curing reaction of the epoxy resin and TBBA, it is preferable to use at least one of imidazoles, amines, and ammoniums as a curing agent. 2-Methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole and the like as imidazoles, benzyldimethylamine and the like as amines, tetramethylammonium chloride and tetraethylammonium as ammoniums Chlorides and the like can be used. The varnish of the curable epoxy resin composition obtained as described above is supplied to an impregnation device, and a substrate such as glass cloth is dipped to impregnate the substrate with the curable epoxy resin composition. A prepreg can be obtained by heating and drying this in an oven or the like. Further, by laminating several prepregs thus obtained and laminating a metal foil such as a copper foil if necessary, and heat-pressing this in accordance with a conventional method, a laminated plate for electrical use can be obtained. It is a thing.

【Example】

The invention will now be illustrated by the examples. (Example) Epoxy resin and TBBA having the composition shown in Table 1 were dissolved in a 1: 1 mixed solvent of methyl ethyl ketone (MEK) and propylene glycol monomethyl ether (PC), and this is shown in the column of reaction conditions in Table 1. The epoxy resin was reacted with TBBA by heating under the conditions, and a curing agent was further compounded to obtain a varnish of the curable epoxy resin composition. The gel time of this varnish at 170 ℃ is the first
Shown in the table. In Table 1, epoxy resin and TBBA
The compounding amount of 2E4MZ (2-ethyl-) is shown by the ratio of the equivalents of both glycidyl ether groups and phenolic OH groups.
The compounding amount of 4-methylimidazole) is shown as a percentage with respect to the resin content. (Comparative Example) A varnish of an epoxy resin composition was prepared by blending a curing agent and a curing accelerator in an epoxy resin and dissolving the mixture in a solvent in the same manner as in the above example. In Table 1, epoxy resin and Di
The compounding amount of CY (dicyandiamide), 2E4MZ is shown in parts by weight. The varnishes prepared in Examples and Comparative Examples as described above have 76
Dip a 28-type glass substrate, and
Impregnation was performed with an impregnation amount of weight% (solid content conversion). This 15
A prepreg was obtained by drying in an oven at 5 ° C for 8 minutes. Eight sheets of this prepreg were piled up, and copper foils having a thickness of 18 μm were piled up and down, respectively, and the molding pressure was 30 kg / cm ² , the molding temperature was 170 ° C., and the molding time was 90 minutes.
A copper-clad laminate having a thickness of 1.6 mm for a printed wiring board was obtained by molding under the condition of minutes. Regarding the laminated plate obtained as described above, oven heat resistance, copper foil peeling strength, solder heat resistance at 288 ° C., 2 atm.
After conducting a pressure cooker test (PCT) under the conditions of 131 ° C. and 150 minutes, the solder heat resistance at 288 ° C. was measured. The results are shown in Table 1. As can be seen from the results in Table 1, the heat resistance of the examples is generally superior to the heat resistance of the comparative examples using the brominated bisphenol A type epoxy resin as the epoxy resin. Is confirmed to be insufficient.

【The invention's effect】

As described above, the epoxy resin composition of the present invention contains at least one epoxy resin having a general formula represented by the above formula (I) and tetrabromobisphenol A as main components, and an epoxy resin and tetrabromobisphenol A. Of the glycidyl ether group and the phenolic OH group in an equivalent ratio of 1: 1 to 1: 0.7, and the glycidyl ether group of the epoxy resin reacts with the phenolic OH group. Tetrabromobisphenol A can be added to improve the general heat resistance of the epoxy resin.

Claims (1)

[Claims] 1. The general formula is The main component is at least one epoxy resin represented by and tetrabromobisphenol A, and the compounding ratio of the epoxy resin and tetrabromobisphenol A is 1: 1 in the equivalent ratio of the glycidyl ether group and the phenolic OH group.
1: 0.7 The curable epoxy resin composition characterized by the above-mentioned.