Abstract
Molding powder was prepared with poly p-vinyl phenol, epi-bis-type epoxy resin and silica flour as a filler. This system can allow much filler as shown in Table 1; a mixture of all raw materials becomes tack-free by mixing in a sigma-type kneader, though liquid epoxy is used as one of the raw materials. The mixture is homogenized on a two-roll mill. The molding powder obtained by this process (MCA) has long flowability (Fig. 2) and short molding time (Figs. 3, 4 and 5). Properties of the molded MCA are shown in Table 2. The molded MCA shows such particular thermal properties that thermal expansion is small and at temperatures over 200°C apparrent heat deflection decreases (Fig. 5), and has the same characteristic as the conventional epoxy moldings in mechanical and electrical properties at the ambient temperatures.
