초록 ▼

This invention provides an expanded open-cell foam polymer composition comprising at least one linear or modified linear polyolefin, at least 50% of the cells being open, and the cells having an average size of at least 1 millimeter. It is desirable that the composition have a sound absorption coeff

This invention provides an expanded open-cell foam polymer composition comprising at least one linear or modified linear polyolefin, at least 50% of the cells being open, and the cells having an average size of at least 1 millimeter. It is desirable that the composition have a sound absorption coefficient as determined by ASTM D 1050 at 1,000 Hz which is greater than 0.15. In preferred foams the composition has an airflow resistivity of less than about 800,000 Rayls/m.

대표청구항 ▼

This invention provides an expanded open-cell foam polymer composition comprising at least one linear or modified linear polyolefin, at least 50% of the cells being open, and the cells having an average size of at least 1 millimeter. It is desirable that the composition have a sound absorption coeff

This invention provides an expanded open-cell foam polymer composition comprising at least one linear or modified linear polyolefin, at least 50% of the cells being open, and the cells having an average size of at least 1 millimeter. It is desirable that the composition have a sound absorption coefficient as determined by ASTM D 1050 at 1,000 Hz which is greater than 0.15. In preferred foams the composition has an airflow resistivity of less than about 800,000 Rayls/m. polyethylene. 8. The expanded foam of claim 1, wherein the linear or modified linear polyolefin is a modified linear polyolefin and the modified linear polyolefin is blended with another polyolefin having a melting point lower than that of the modified linear polyolefin. 9. The expanded foam of claim 2, wherein the other polyolefin is a substantially linear polyolefin. 10. The expanded foam of claim 9, wherein the linear or modified linear polyolefin comprises at least 50 weight-percent of the total polymer weight of the composition. 11. The expanded foam of claim 9, wherein the other polyolefin comprises less than 40 weight percent of the total polymer weight of the composition. 12. The expanded foam of claim 1, wherein the foam has a density less than 160 kilograms per cubic meter. 13. The expanded foam of claim 1, wherein the foam has a density less than 80 kilograms per cubic meter. 14. The expanded foam of claim 1, wherein the foam has a density less than 40 kilograms per cubic meter. 15. The expanded foam of claim 1, wherein the average cell size is at least 1.5 millimeters. 16. The expanded foam of claim 1, wherein the average cell size is at least 2 millimeters. 17. The expanded foam of claim 1, wherein at least 70% of the cells are open determined according to ASTM D2856-A. 18. The expanded foam of claim 1, wherein at least 85% of the cells are open determined according to ASTM D2856-A. 19. The expanded foam of claim 9, wherein the other polyolefins a substantially linear copolymer of ethylene with α-olefin. 20. The expanded foam of claim 1, wherein the foam has been extruded in the form of a sheet. 21. The expanded foam of claim 1, wherein the polymer composition comprises a cross-linked polymer. 22. The expanded foam of claim 21, wherein the cross-linked polymer is the product of an olefinic polymer having pendant carboxylic acid functional groups, pendant hydroxyl functional groups, pendant amino functional groups, pendant amide functional groups, or a combination thereof, with a cross-linking agent selected from the group consisting of epoxy functional silanes, amine functional silanes, organofunctional alkoxy silanes, titanates, multi-epoxy functional resins, and amino cross-linking agents. 23. The expanded foam in claim 21, wherein the cross-linked polymer has been prepared by the use of a free-radical generating compound. 24. The expanded foam of claim 23 wherein free-radical generating compound is an organic peroxide. 25. The expanded foam of claim 23 wherein free-radical generating compound is a multi-azidofunctional compound. 26. The expanded foam of claim 9, 10 or 11 wherein the expanded foam is perforated at a hole density of greater than one hole per five square centimeters. 27. A sound insulation panel comprising two skin layers and a foam sheet disposed between the two skin layers, the foam sheet comprising an expanded foam of claim 1. 28. The panel of claim 27, wherein the expanded foam has a sound absorption coefficient as determined by ASTM D 1050 at 1,000 Hz which is greater than 0.15. 29. A foam sheet comprising the expanded foam of claim 1 having a sound absorption coefficient as determined by ASTM D 1050 at 1,000Hz which is greater than 0.15. 30. A foam sheet comprising the expanded foam of claim 1, wherein the expanded foam has at least 70 percent open cells, a cell size of at least 1.5 mm and a compressive strength less than 30 kPa at 10 percent deflection.