Patent ID: 6060533
Filing Date: 2000-05-09
Classification: C08J,C08L

Abstract:
A method for making a foam articles comprising:(1) irradiating a propylene polymer material selected from the group consisting of(a) a terpolyrner of propylene, ethylene, and butene-1 comprising about 85% to about 96% propylene, about 1.5% to about 5% ethylene, and about 2.5% to about 10% butene-1, wherein the total comonomer concentration with propylene is about 4.0% to about 15%;(b) a polyolefin composition comprising (i) about 31% to about 39% of a copolymer of propylene and ethylene having an ethylene content of about 1.5% to about 10%, (ii) about 58% to about 72% of a terpolyrner of propylene, ethylene, and butene-1 having a propylene content of about 85% to about 96%, an ethylene content of about 1.5% to about 6%, and a butene-1 content of about 2.5% to about 12%, wherein the total comonomer concentration with propylene is about 4.0% to about 18%; and(c) a polyolefin composition comprising (i) about 30% to about 65% of a copolymer of propylene and butene-1 having a propylene content of about 80% to about 98%, and (ii) about 35% to about 70% of a copolymer of propylene and ethylene having an ethylene content of about 2% to about 10%, and(2) extruding the irradiated propylene polymer material through a die in the presence of a physical expanding agent and a cell nucleating agent, whereby a foam article is formed whose density is at least 10.times. less than the initial density of the propylene polymer material.