Patent ID: 6066682
Filing Date: 2000-05-23
Classification: C08J

Abstract:
A foam consisting essentially of a polyvalent metal salt-crosslinked cellular homopolymer or copolymer (A) obtained by radically polymerizing in the presence of a cell regulator or a surfactant, a monomer charge consisting essentially of an .alpha., .beta.-unsaturated carboxylic acid and optionally at least one other vinyl monomer than said .alpha., .beta.-unsaturated carboxylic acid, wherein at least 50 weight % of said monomer charge is polymerized in the presence of a polymerization initiator, concurrently with crosslinking and foaming through a polyvalent metal salt of carbonic acid acting as a crosslinking agent and a blowing agent, the proportion of the .alpha., .beta.-unsaturated carboxylic acid constituting the polyvalent metal salt-crosslinked cellular homopolymer or copolymer (A) being not less than 30 weight % based on the weight of the polyvalent metal salt-crosslinked cellular homopolymer or copolymer (A) and sufficient to provide a flame retardancy grade of Grade 1 or 2 of JIS A-1321.