| 摘要 |
<p>PURPOSE:To prevent the occurrence of warpages or the residue of voids by specifying the initial pressure of molding and raising the molding pressure into a specific pressure before the resin in a prepreg reaches the lowest melting viscosity and the viscosity rises rapidly and making a specific pressure during the time of cooling. CONSTITUTION:In an epoxy resin laminate layered board, when a prepreg employing as a sheet base material a glass non-woven fabric is heat-press molded as a part or the whole of the prepreg, the initial molding pressure is made into 20 -40 kg/cm<2>, and thereafter the pressure is raised to 60 - 80 kg/cm<2> before the viscosity rises rapidly after the resin in the prepreg melts and then reaches the lowest melting viscosity. The pressure is made into 5 - 20 kg/cm<2> at the cooling process after the molding. By raising the pressure at the time when the melting viscosity of the resin becomes lowermost, the air bubbles stayed in the inner part is sent outward together with the flow of the resin and by lowering the pressure at the cooling process, distortion is released which is caused at the time when the molding is effected at a high pressure. By this method, an epoxy resin can be manufactured wherein the residue of voids is restrained and the dimensional alteration and the warpage are small.</p> |
