| 摘要 |
PURPOSE:To obtain a laminated sheet having improved surface smoothness and soldering temperature resistance and high puntchability, by impregnating a paper substrate with an epoxy resin varnish containing specific two kinds of aromatic amines, and laminating the obtained prepregs with a hot-press. CONSTITUTION:A varnish produced by mixing an epoxy resin with >=2 kinds of aromatic amines having different reactivity to epoxy resin and optionally an epoxy resin accelerator such as a Lewis acid complex catalyst, imidazole, tertiary amine, etc., is impregnated in a paper substrate and dried to obtain a prepreg. The prepregs are laminated with a hot-press to form a laminate sheet, which may be applied with an adhesive and dried. The aromatic amine is e.g. m-xylenediamine, toluylenediamine, chloroaniline, diaminodiphenyl ether, etc., and the total amount of the amine is 0.6-0.9 equivalent based on the epoxy group. |
