Patent ID: 7649052
Filing Date: 2010-01-19
Classification: C08L

Abstract:
1. A heterophasic polyolefin composition comprising (percent by weight): (A) from 50 to 80% by weight of a crystalline propylene polymer having a polydispersity index value from 5.2 to 10, and a content of isotactic pentads (mmmm), measured by (B) from 5 to 20% by weight of a first elastomeric ethylene/propylene copolymer; said first elastomeric ethylene/propylene copolymer comprising from 25% to less than 40% by weight of ethylene, and is soluble in xylene at room temperature in an amount from higher than 85% to 95% by weight, wherein the xylene soluble fraction has an intrinsic viscosity [η] ranging from 2.5 to 4.5 dL/g; and (C) from 10 to 40% by weight of a second elastomeric ethylene/propylene copolymer; said second elastomeric ethylene/propylene copolymer comprising from 50% up to 75% by weight of ethylene, and is soluble in xylene at room temperature in an amount from 50% to 85% by weight, wherein the xylene soluble fraction has an intrinsic viscosity [η] ranging from 1.8 to 4.0 dL/g; wherein the sum of amounts of copolymer (B) and copolymer (C) ranges from 20 to 45% by weight based on the total amount of components (A) to (C), the total amount of ethylene based on the total amount of components (A) to (C) is up to 23% by weight, and the ratio between the ethylene content of the fraction insoluble in xylene at room temperature (C and wherein x is a total amount of ethylene.