STYRENE-BASED EXPANDABLE RESIN PARTICLE, FOAMED BEAD AND EXPANSION MOLDING PRODUCT

摘要

PROBLEM TO BE SOLVED: To provide styrene-based expandable resin particles having good appearance of molding product and excellent in expansion molding properties and to provide a method for producing the resin particles and to provide styrene-based foamed beads and expansion molding products. SOLUTION: The method for producing the styrene-based expandable resin particles comprises advancing polymerization reaction while keeping the interior of a reacting tank in a low oxygen concentration from the start of polymerization in suspension polymerization of a styrene-based monomer and impregnating a readily volatile foaming agent before or after completion of polymerization reaction. In the styrene-based expandable resin particles obtained by the production method, the expandable molding product having good appearance can be obtained, because the occurrence of a low molecular weight product is suppressed in the outermost layer part. COPYRIGHT: (C)2004,JPO