| 摘要 |
PURPOSE:To obtain the title laminate improved in flame retardancy, heat resistance and punching quality by impregnating paper bases with a specified resin varnish containing Sb2O5 and then impregnating them with a resin varnish containing a flame retardant. CONSTITUTION:A primary impregnation resin varnish (A) is obtained by dispersing Sb2O5 in a resin varnish obtained by dissolving a condensate of an alkylphenol-containing phenol with melamine in a solvent containing a volatile organic solvent (e.g. acetone) and water. A secondary impregnation hydrophobic resin varnish (B) is obtained by mixing a resin varnish such as phenolic resin or an epoxy resin with a flame retardant (e.g. tetrabromobisphenol A). Paper bases are impregnated with component A and then with component B and dried. The obtained resin-impregnated bases are laminated optionally together with metallic foils and press-molded. |
