METHOD FOR PRODUCTION OF UNCROSSLINKED POLYOLEFIN RESIN FOAM

摘要

Disclosed is a method for producing a foam which has an expansion ratio of 3 to 10 times, has an uniform and microfine cell structure, and has excellent thermal insulation properties, surface smoothness and recycling efficiency. Specifically disclosed is a method for producing an uncrosslinked polyolefin resin foam, which comprises heat-melting a mixture comprising 100 parts by mass of an polyolefin resin and 3 to 10 parts by mass of a chemical foaming agent substantially in the absence of a crosslinking agent to expand the mixture, wherein the polyolefin resin is mainly composed of a linear polypropylene resin having a melt tension of 5 to 30 g at 230°C, and the chemical foaming agent comprises an inorganic hydrogen carbonate and an organic carboxylic acid salt.