Patent ID: 6827891
Filing Date: 2004-12-07
Classification: B29C,C08J

Abstract:
A method for production of foamed plastics comprising: adding particles containing 30 to 70% by weight of water in thermoplastic resin; mixing, heating and melting said thermoplastic resin in which said particles have been added at high pressure; then releasing said high pressure acting on the resulting mixture to foam said mixture of said thermoplastic resin and said particles; and cooling said foamed mixture, wherein the average diameter of said particles containing the water is 30 to 200 &mgr;m and 0.1 to parts by weight of said particles are added in 100 parts by weight of said thermoplastic resin, said particles containing the water are porous particles of a synthetic resin, and said porous particles of synthetic resin are produced by dispersing the water with a surface active agent in an oil phase which is a mixture of an unsaturated polyester and a vinyl monomer which can react with said unsaturated polyester to form cross-linking to prepare an emulsion, and re-dispersing said emulsion in the water and curing said mixture to form cross-linking.