Patent ID: 6590006
Filing Date: 2003-07-08
Classification: C08J

Abstract:
A cellular thermoplastic polymer foam having an average cell size of at least about 1.5 mm, a density not greater than about 300 kg/m3, an average sound absorption coefficient of at least about 0.2, and a heat distortion temperature of at least about 110 degrees Celsius, wherein the thermoplastic polymer comprises:(A) at least one predominantly isotactic, propylene polymer having a tan &dgr; value not greater than 1.5 and optionally (B) at least one ethylene polymer produced via a free radical process blended with the propylene polymer, wherein the thermoplastic polymer foam satisfies at least one of the following two conditions: the thermoplastic polymer comprises ethylene polymer blended with the propylene polymer and the weight ratio of the propylene polymer (A) to the ethylene polymer (B) is at least about 35:65 and/or the foam has at least one surface, the at least one surface having defined therein a multiplicity of perforation channels extending from the at least one surface into the foam such that there is an average of at least one perforation channel per 10 square centimeters of the at least one surface.