Patent ID: 8017206

Claim:
Pipe systems comprising at least one layer comprising a semi-crystalline random polymer of propylene and 1-hexene, wherein the semi-crystalline random polymer comprises from 0.2 to 5% by wt. of recurring units derived from hexene-1, and the semi-crystalline random polymer comprises: a) a broad molecular weight distribution ranging from 5 to 11, in terms of a ratio of weight average molecular weight to numeric average molecular weight ( M w/ M n); b) a monomodal molecular weight distribution; c) a fraction with an intrinsic viscosity equal to or higher than 3.3 dl/g comprising hexene-1; and d) a fraction with an intrinsic viscosity less than 3.3 dl/g comprising hexene-1; wherein the fraction with the intrinsic viscosity equal to or higher than 3.3 dl/g comprising hexene-1 is lower in amount than the fraction with the intrinsic viscosity less than 3.3 dl/g comprising hexene-1.