Leading press mass

摘要

An improved molding composition having a bulk resistivity below about 500 ohm-cm at 900 megahertz for compression molding video discs comprising sufficient conductive carbon black particles to obtain the desired conductivity, from about 1.5 to 4 percent by weight of stabilizers, from about 1 to 3 percent by weight of at least two lubricants, up to 10 percent by weight of plasticizers and processing aids, the remainder being a polyvinylchloride based resin, with the proviso that not more than about 5 percent by weight of liquid additives are present in said molding composition. Video discs molded from said composition have improved dimensional stability.