| 摘要 |
PURPOSE:The base is, before being impregnated with a thermosetting resin, pretreated with a mixture of a water-soluble phenolic resin and a novolak type phenolic resin to give laminated plates with high dimensional stability, heat resistance and good punching properties. CONSTITUTION:At first, the base such as kraft paper is pretreated with a mixture of (A) a water-soluble phenolic resin and (B) a novolak type phenolic resin, preferably the content of component B is 20-60wt%, then impregnated with (C) a thermosetting resin, preferably modified with a drying oil. The products are dried and the resultant prepregs are laminated to give the objective plates. The resin B is preferably obtained by allowing formaldehyde to react with phenol so that the molar ratio is 0.1-0.4. |
