PRE-EXPANDED NONCROSSLINKED POLYPROPYLENE RESIN BEADS AND IN-MOLD EXPANSION MOLDINGS

摘要

Pre-expanded beads of a noncrosslinked polypropylene resin composition which contains 1 to 30 % by weight of an ionically conductive polymer type antistatic agent consisting of an amphiphilic block copolymer containing an alkali metal fluoroalkylsulfonate; a process for the production of in-mold expansion moldings of noncrosslinked polypropylene resin which comprises packing the pre-expanded beads into a mold which can hold the beads in an occluded state but cannot hold the same in a hermetically sealed state and heating the beads with steam to mold them; and expansion moldings obtained by the process. The invention provides pre-expanded noncrosslinked poly- propylene resin beads which are excellent in antistatic properties and enable the production of substantially stainless in-mold expansion moldings; and in-mold expansion moldings made from the beads.