PRODUCTION OF RESIN FOAM HIGHLY LOADED WITH INORGANIC MATERIAL, AND FOAM

摘要

PURPOSE:To produce the title foam which has excellent mechanical characteristics and void-free smooth surface skins by exposing to an electron beam both the surfaces of a foamable resin sheet comprising an EVA copolymer compsn. highly loaded with an inorg. material to thereby uniformly cure the sheet and thermaly foaming it. CONSTITUTION:Both the surfaces of a foamable resin sheet made from a compsn. contg. 100 pts.wt. thermoplastic resin consisting solely or mainly of an EVA copolymer having a vinyl acetate content of 40wt.% or lower and 50-300 pts.wt. inorg. material are exposed to an electron beam in such a manner that the resulting foamed sheet has a gel fraction in the thickness direction and a difference between the max. and the min. gel fraction in the same direction of 15-50% and 20% or lower, respectively.