OPEN-CELL SOUND-ABSORBING POLYOLEFINS AND A METHOD FOR PREPARATION THEREOF Russian patent published in 2004 - IPC

FIELD: polymer materials. SUBSTANCE: invention relates to foamed materials suitable for absorption of sound and used in motor cars and equipment. Foamed polymer composition in the form of expanded foam with open cells contains at least one linear or modified linear polyolefin combined with other polyolefin with melting point below that of linear polyolefin. Foam has preferably resistance against passage of air flow below 800000 Pa.s/sq.m and sheet foam has coefficient of sound absorption above 0.15 as measured at 1000 Hz in accordance with ASTM D 1050. EFFECT: improved sound- absorption characteristics and hydrolytic stability for long-term use in contact with water and an elevated-moisture medium, improved structural integrity at moderate density. 29 cl, 7 dwg, 5 tbl, 5 ex