Injection molding of styrene resin

摘要

A method of injection molding a styrene resin or a composition thereof, which includes injection molding a molten molding resin material of a styrene-conjugated diene block copolymer containing 50 to 90% by weight of a styrene polymer or a molten molding resin material of a resin composition comprising 50% by weight or more of the styrene-conjugated diene block copolymer and 50% by weight or less of a styrene resin other than the styrene-conjugated diene block copolymer, wherein the molten resin is injected and filled into a mold with a wall surface temperature at core and cavity portions within the mold being made 110 DEG to 180 DEG C., and the molded product is demolded when the wall surface temperature of the core and cavity portions is lowered to the glass transition temperature or lower of the styrene polymer moiety in the block copolymer. The obtained molded product has a high impact resistance.