High mixture-quality bi-modal polyethylene blends

US6545093B1 · kind B1 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Paulus De Lange · Wesseling, DE
• Andreas Deckers · Flomborn, DE
• Thomas Kessler · Schifferstadt, DE
• Wolfgang Rohde · Speyer, DE
• Thomas Blümel · Rodenbach, DE
• Martin Lux · Schifferstadt, DE

Key dates

• Filing date: Apr 2, 2001
• Grant date: Apr 8, 2003
• Expiry date: Apr 2, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2314/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Bimodal polyethylene blends are made from a high-molecular-weight ethylene copolymer and a low-molecular-weight ethylene homo- or copolymer and have a melt flow rate MFR 190/21.6 of from 6 to 14 g/10 min, a density of from 0.94 to 0.97 g/cm3, an environmental-stress-cracking resistance ESCR>150 h and a value of less than 3 when the quality of blending in the blend is measured to ISO 13949. A process prepares polyethylene blends of this type by melting and homogenization in a mixing apparatus and discharge via a gear pump. The blends are used to produce moldings, in particular hollow articles and pressure pipes.