EXPANDABLE STYRENE RESIN PARTICLE AND ITS PRODUCTION

摘要

PURPOSE: To obtain expandable styrene resin particles which give a molding with a high expansion ratio and high strengths. CONSTITUTION: This particles comprise styrene resin particles each of which comprises the outermost low-mol.-wt. layer, the intermediate high-mol.-wt. layer, and the central low-mol.-wt. part and has been impregnated with an easily volatile blowing agent. The expandable particles are produced by polymerizing a styrene monomer in the presence of low-mol.-wt. styrene resin particles and a catalyst to form the intermediate high-mol.-wt. layer and the outermost low- mol.-wt. layer and impregnating the resulting resin particles with the blowing agent during or after the polymn.