Patent ID: 7265160

Claim:
A crosslinked biodegradable resin foamed sheet comprising an irradiated crosslinked polymer comprising a biodegradable resin and a crosslinking promoter selected from the group consisting of methacrylates and acrylates, wherein the biodegradable resin is at least one selected from the group consisting of polylactic acid, biodegradable aliphatic polyesters prepared by polycondensation, biodegradable aromatic copolyesters prepared by polycondensation, lactone resins, biodegradable cellulose esters, polypeptides, polyvinyl alcohol, starch, cellulose, chitinchitosans and natural linear polyester resins; and wherein the foamed sheet has an expansion rate of 1.5 to 50 and a gel fraction of at least 3%.