Macrocellular polyolefin foam having high service temperature for acoustical applications

• Main Author: C.P. PARK,S. GILG,S. SUBRAMONIAN
• Format: Patent
• Language: English
• Published: 01.11.2006
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; VEHICLES IN GENERAL; VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISEPROVIDED FOR; WORKING-UP

Macrocellular polyolefin foams that can withstand temperatures above 110° C. are described for use in sound absorption and insulation applications, especially in elevated temperature and/or moist environments. These foams have a large cell size (>=1.5 mm), are open or closed-cell foams, and preferably have at least one perforation per square centimeter and/or a density less than 25 kg/m3. They are obtainable by extruding a high melt strength (HMS) polypropylene resin (PP), or preferably a blend of a HMS PP resin and a free radical polymerized ethylene polymer present in the blend in a weight ratio of at least 35:65, optionally another polymer such as a substantially random interpolymer, a cell size enlarging agent such a glycerol monostearate, an antioxidant, carbon black and/or flame retardant additives, using a volatile organic compound, e.g. isobutane, as blowing agent.