Polymer composition for pipes

US6878784B1 · kind B1 · utility

Assignee

• Borealis Technology AG · FI

Inventors

• Markku Asumalahti · Kerava, FI
• Jari Äärilää{umlaut over ( )} · Porvoo, FI
• Ari Palmroos · Kerava, FI
• Mats Bäckman · Gothenburg, SE
• Anette Nilsson · Mönsterås, SE
• Magnus Palmlöf · Svenljunga, SE

Key dates

• Filing date: Jul 1, 1999
• Grant date: Apr 12, 2005
• Expiry date: Jul 1, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/1397
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A multimodal polymer composition for pipes is disclosed. The polymer is a multimodal polyethylene with a density of 0.930-0.965 g/cm3, an MFR5 of 0.2-1.2 g/10 min, an Mn of 8000-15000, an Mw of 180-330×103, and an Mw/Mn of 20-35, said multimodal polyethylene comprising a low molecular weight (LMW) ethylene homopolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction, said HMW fraction having a lower molecular weight limit of 3500, and a weight ratio of the LMW fraction to the HMW fraction of (35-55):(65:45).