Production of foam

摘要

A method for producing cross-linked polyethylene resin foams which comprises mixing a polyolefin resin, a blowing agent and, optionally, a surface active agent containing hydroxyl groups or an acid amide compound under pressure, said polyolefin resin containing a cross-linkable ethylene polymer having on the side chains thereof silyl groups which effect cross-linking upon contact with water; extruding the mixture into a low pressure zone where the extrudate is allowed to expand; and bringing the expanded extrudate into contact with a silanol condensing catalyst so that the expanded extrudate is cross-linked on contact with water.