Abstract: The present invention concerns a multimodal polyethylene composition comprising a base resin comprising a copolymer of ethylene and at least one comonomer selected from alpha-olefins having from 3 to 10 carbon atoms, wherein the base resin has (a) a density of at least 945.0 kg/m3 and not more than 955.0 kg/m3, determined according to ISO 1183-1:2004, (b) a melt flow rate MFR5 (190° C., 5 kg), determined according to ISO 1133, of from 0.15 to 0.25 g/10 min., and wherein the polyethylene composition has (c) a molecular chain length, determined according to Quantitative 13C{1H} NMR analysis, of at least 850 and not more than 1200, and (d) a tensile modulus of at least 900 MPa and not more than 1200 MPa, determined according to ISO 527-3, a method for its production, a pipe or fitting comprising it and its use for increasing the pressure resistance and/or the slow crack growth resistance of a pipe or fitting.

Abstract: The present invention relates to a polyethylene composition comprising a base resin which comprises (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene copolymer fraction, wherein fraction (A) has a lower molecular weight than fraction (B), fraction (A) is present in an amount of 45.0 to 55.0 wt. %, preferably 46.0 to 53.0 wt. %, more preferably 46.5 to 52.0 wt. %, based on the total weight of the base resin, fraction (B) is present in an amount of 55.0 to 45.0 wt. %, preferably 54.0 to 47.0 wt. %, more preferably 53.5 to 48.0 wt. %, based on the total weight of the base resin, the base resin has a density of 945 kg/m3 to 958 kg/m3, more preferably of 947 to 956 kg/m3, and most preferably of 948 kg/m3 to 954 kg/m3, the polyethylene composition has a melt flow rate MFR5 of 0.15 to 0.30 g/10 min, preferably of 0.20 to 0.29 g/10 min, and still more preferably of 0.22 to 0.