Patent ID: 7416686

Claim:
A polymer composition for the manufacture of pipes that have a design stress of at least 9.0 MPa (PE112), the polymer composition comprising 92-99% by weight of a bimodal ethylene polymer and 1-8% by weight of carbon black, said composition having an MFR 5 in the range of 0.15 to 0.40 g/10 min and a density in the range of 955 to 965 kg/m 3 , said polymer being composed of 42-55% by weight of a low molecular weight ethylene homopolymer having an MFR 2 in the range of 350 to 1500 g/10 min and 58-45% by weight of a high molecular weight copolymer of ethylene with 1-hexene, 4-methyl-1-pentene, 1-octene and/or 1-decene.