| 摘要 |
PURPOSE:To obtain an electric conductive thin plate whose electric resistance is lower than 10 deg.OMEGAcm and having no gas permeability, by premolding a powder mixture of a carbon conductive material and a thermosetting resin at a temperature 10-15 deg.C lower than the softening temperature of the mixture and under a pressure lower than the pressure applied at the main molding pressure. CONSTITUTION:A mixture of a carbon conductive material selected from one or more than one of carbon, graphite and carbon fiber and a thermosetting resin such as phenolic resin and so on is uniformly placed by means of an appropriate special tool in a metal mold whose temperature is controlled at a temperature 10-15 deg.C lower than the softening temperature of the mixture and pre-molded under a pressure lower than the pressure applied at the main molding pressure. The mixture is thereafter molded by heating and pressing under an ordinary molding condition to obtain an electric conductive thin plate. Lower the pre-molding temperature, slower the curing speed of the mixture and more hardly clods of the mixture occur. It is therefore easier to fill the mixture in the metal mold and the deformation of the pre-molded molding is smaller when the molding is taken out of the metal mold. As the internal stress produced in the molding is larger at the pressed surface and smaller at the opposite side, it is possible to make the internal stress in the molding more uniform by reversing the directions of premolding and the main molding. |
