| 摘要 |
PURPOSE: To obtain a prepreg excellent in heat resistance and dimensional stability, extremely little in left voids, capable of being rapidly cured, and useful for electric laminates, by impregnating a varnish containing a specific epoxy resin in a fiber substrate and subsequently drying the impregnated varnish. CONSTITUTION: A varnish comprising an epoxy resin composition containing (A) epoxy resins having two or more epoxy groups, which contain an epoxy resin of formula I (G is group of formula II) in an equivalent ratio of 10-50%, (B) an aromatic polyamine [e.g bis(4-amino-3-ethyl-5-methylphenyl)methane], and (C) a guanide compound (e.g. 1-o-tolyldiguanide) preferably in an equivalent ratio of 1, 0.1-0.8, 0.05-0.8, respectively, is impregnated in a fiber substrate and subsequently dried to obtain the objective prepreg. (D) Dicyandiamide is preferably further added to the composition in a ratio of 0.1-0.8 equivalent per equivalent of the component A. |
