Patent ID: 6746640
Filing Date: 2004-06-08
Classification: C08F,Y10T

Abstract:
A method for making a molded article comprising the steps:(1) providing at least one mold charge unit having a molding composition comprising (a) from about 10 to about 25% by weight of a liquid polymerizable material including at least one volatile monomer reactive material, (b) at least one primary thermal initiator having a primary thermal initiator ten-hour half-life temperature, (c) at least one secondary thermal initiator having a secondary thermal initiator ten-hour half-life temperature of at least about 5Â° C. greater than the primary thermal initiator ten-hour half-life temperature; (2) placing the at least one mold charge unit in a mold cavity of a mold, the mold cavity having a preheated mold temperature sufficient to cause the secondary thermal initiator to pass through from about three to about ten half lives within about ten minutes or less; (3) applying pressure to the mold to a molding pressure sufficient to maintain an internal geometric integrity and a surface geometric integrity of the molded article; (4) maintaining the preheated mold temperature and the molding pressure for a time sufficient to ensure that the secondary thermal initiator has passed through from about three to about ten half lives.