Process for coating a pipe with high throughput using multimodal ethylene copolymer, and coated pipes obtained thereof

摘要

The present invention deals with coated pipes having a layer of multimodal polyethylene. The multimodal ethylene copolymer is a copolymer of ethylene with one or more alpha-olefin comonomers having from 4 to 10 carbon atoms and has a weight average molecular weight of from 70000 g/mol to 250000 g/mol, the ratio of the weight average molecular weight to the number average molecular weight, Mw/Mn, of from 15 to 50, a melt index MFR 2 of from 0.05 g/10 min to 5 g/10 min, a melt index MFR 5 of from 0.5 to 10 g/10 min and a density of from 930 kg/m 3 to 955 kg/m 3 . The pipes can be coated with high throughput and good production economy. The coatings have good mechanical properties.