POLYETHYLENE MOULDING COMPOUND WITH AN IMPROVED ESCR-STIFFNESS RELATION AND AN IMPROVED SWELLING RATE, A METHOD FOR THE PRODUCTION THEREOF AND THE USE THEREOF

摘要

The invention relates to a polyethylene moulding compound with multimodal molar weight distribution. Said moulding compound is provided with a total density of >= 0.940 g/cm3 and an MFI190/5 in the range of 0.01 to 10 dg/m in. The inventive moulding compound contains 30 to 60 wt. % of low-molecular ethylene homopolymer A which is provided with a viscosity number VZA in the range of 40 to 150 cm3/g. The moulding compound also comprises 30 to 65 wt. % of a high-molecular copolymer B consisting of ethylene and an additional olefin with 4 to 10 C-atoms and having a viscosity number VZB in the range o f 150 to 800 cm3/g. Said moulding compound further comprises 1 to 30 wt. % of ultrahigh-molecular ethylene homopolymer C which is provided with a viscosit y number VZC in the range of 900 to 3,000 cm3/g. The invention also relates to a method for producing the moulding compound in a three-step process and to th e use thereof for producing hollow bodies.