Basell Polyolefine Gmbh

Hansjörg Nitz

Heinz Vogt

Joachim Berthold

Ulrich Schulte

Werner Rothhöft

A polyethylene molding composition having a multimodal molecular mass distribution and comprising from 45 to 55% by weight of a low molecular weight ethylene homopolymer A, from 20 to 40% by weight of a high molecular weight copolymer B comprising ethylene and another olefin having from 4 to 8 carbon atoms and from 15 to 30% by weight of an ultrahigh molecular weight ethylene copolymer C can be prepared in the presence of a Ziegler catalyst in a three-stage process and is highly suitable for producing pipes having excellent mechanical properties.

Multimodal polyethylene molding composition for producing pipes having improved mechanical properties

A molding composition is suitable for the production of pipes having improved resistance to thermooxidative degradation when these pipes are in long-term contact with liquids comprising disinfectants having an oxidizing effect. Such molding composition comprises, in addition to thermoplastic polyolefins, a polyoxy compound and/or a polyhydroxy compound as additive in an amount of from 0.01 to 1.0% by weight. In addition, the molding composition can further comprise an unsaturated aliphatic hydrocarbon in an amount of up to 5% by weight. The invention also relates to a process for improving the long-term resistance of water pipes to damage caused by oxidizing disinfectants from the water by use of this molding composition.

Growing community of inventors

Frankfurt-am-Main, Germany

Hansjörg Nitz