| 摘要 |
PURPOSE:To obtain molding material, which does not impair the curing characteristics after its shaping in a mold by a method wherein a specified crosslinking agent is added to ordinary molding material stocks. CONSTITUTION:The concerned thermosetting resin composition for injection molding is produced by adding alpha,alpha'-dimethoxy-p-xylene to phenolic resin, hexamethylene tetramine, filler and compounding agent. The mold filling time of the above-mentioned composition is less than or equal to 15 sec, even when the detention time in a cylinder exceeds 4 min under the conditions that a thermosetting resin injection molder, which is equipped with a standard nozzle of 4.5 mm bore, the mold clamping pressure of which is 45 ton, the front and the rear cylinder temperatures of which are set to be 95 deg.C and the injection pressure of which is set to be 410 kg/cm<2>, and a mold, the capacity of a cavity of which is 42 cm<3> and the temperature of which is set to be 160 deg.C, are employed. In other words, said composition can be injected for molding under the state just mentioned above. As a result, by lowering the injection pressure, the enlargement of the mold projected area, the increase of injection capacity, the reduction of injection energy, the miniaturization of sprue and the like become possible. |
