| 摘要 |
PURPOSE:To obtain a prepreg capable of forming a laminated board at a temperature below 180 deg.C without warpage nor distortion even after heating of formed article by covering a (non)woven cloth with a specific polyamide-imide resin varnish with impregnation and drying at specific temperature for specific timing. CONSTITUTION:A (non)woven cloth composed of at least one of glass fiber, carbon fiber and aramid fiber, etc., is covered with a polyamide-imide resin varnish composed of a tribasic acid anhydride (e.g. trimellitic anhydride), dicarboxylic acid (e.g. isophthalic acid) and diisocyanate compound (4,4'- diphenylmethane diisocyanate, etc.) by impregnation and abundant of solvent is removed at a temperature and a time simultaneously satisfying relationships expressed by formula I-formula III (T is temperature; t is time), then the resultant system is dried with suppressing hardening. |
