Patent ID: 7592393

Claim:
A polyolefin composition comprising the following fractions: (A) from 8 to 25% by weight of a crystalline polymer fraction selected from the group consisting of: (i) a propylene homopolymer, having solubility in xylene at room temperature lower than 10% by weight; and (ii) a copolymer of propylene and at least one alpha-olefin of formula H 2 C═CHR, where R is H or a C 2-6 linear or branched alkyl, containing at least 85% by weight of propylene, having solubility in xylene at room temperature lower than 15% by weight; and (B) from 75 to 92% by weight of an elastomeric fraction comprising: (1) a first elastomeric copolymer of propylene with at least one alpha-olefin of formula H 2 C═CHR, where R is H or a C 2-6 linear or branched alkyl, optionally containing 0.5 to 5% by weight of a diene, said first elastomeric copolymer containing from 15 to 32% by weight alpha-olefin, and having solubility in xylene at room temperature greater than 50% by weight, the intrinsic viscosity of the xylene soluble fraction ranging from 3.0 to 5.0 dl/g; and (2) a second elastomeric copolymer of propylene with at least one alpha-olefin of formula H 2 C═CHR, where R is H or a C 2-6 linear or branched alkyl, optionally containing 0.5 to 5% by weight of a diene, said second elastomeric copolymer containing more than 32% up to 45% by weight alpha-olefin, and having solubility in xylene at room temperature greater than 80% by weight, the intrinsic viscosity of the xylene soluble fraction ranging from 4.0 to 6.5 dl/g; wherein a (1)/(2) weight ratio ranges from 1:5 to 5:1, and the polyolefin composition has a flexural modulus lower than 60 MPa, a Shore A hardness lower than 90, and a tension set at 100% lower than 35%.