Vinylidene chloride type resin expandable particles, foam particles, in-mold foam molding by use thereof and process for producing them

摘要

This invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, useful as thermal insulating plate materials or anti-shock molded vessels, and foam particles or expandable particles convenient for preparation thereof, and also a series of advantageous foaming techniques for completion of such a molding. The above foam molding can be prepared by bringing fine particles of a non-crystalline vinylidene chloride type resin obtained generally by suspension polymerization into contact with a volatile organic blowing agent thereby impregnating the resins with the blowing agent to form expandable resin particles, which are in turn subjected to expansion as such, or after forming into pre-expanded foam particles including expandable gas therein, by filling in a mold cavity which can be closed but not sealed, under heating to form a molding through fusion mutually between the expanded particles.