| abstract |
The present invention relates to a polymer composition suitable for making pipes. The composition comprises a multimodal copolymer of ethylene and one or more α-olefins having 4 to 10 carbon atoms, the multimodal ethylene copolymer having a density of 937-950 kg / m 3 , 0.3-3.0 g. It has a melt index MFR 5 of / 10 minutes, a melt index MFR 2 of 0.1 to 2.0 g / 10 minutes and a shear thinning index SHI 2.7 / 210 of 2 to 30. In addition, the multimodal copolymer may comprise 30-70 wt% ethylene homopolymer and one or more having 4-10 carbon atoms, based on the total amount of (A) components (A) and (B). Low molecular weight ethylene polymer selected from copolymers with α-olefins and having a weight average molecular weight of 5,000 to 100,000 g / mol and a density of 960 to 977 kg / m 3 , and (B) total amount of components (A) and (B) 30 to 70% by weight of ethylene having a weight average molecular weight of 10,000 to 100,000 g / mol and a density of 890 to 929 kg / m 3 and high of one or more α-olefins having 4 to 10 carbon atoms Has a molecular weight copolymer. [Selection figure] None |