Process for producing multimodal polyethylene blends including ultra-high molecular weight components

US10597470B2 · kind B2 · utility

Assignee

• Borealis AG · AT

Inventors

• Bernd Kretzschmar · Bopfingen, DE
• Carl-Gustaf Ek · Mölndal, SE
• Thomas Ratzsch · Orth an der Donau, AT
• Yi Liu · Linz, AT
• Sandeep Tyagi · Linz, AT

Key dates

• Filing date: Dec 21, 2015
• Grant date: Mar 24, 2020
• Expiry date: Apr 2, 2036

Classification

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

Abstract

The present application relates to a process for producing a multimodal polyethylene composition comprising the steps of blending a polyethylene fraction (A-1) having a weight average molecular weight Mw of equal to or more than 700 kg/mol to equal to or less than 10,000 kg/mol and a density of equal to or more than 920 kg/m3 to equal to or less than 960 kg/m3 and a polyethylene fraction (A-2) having a lower Mw as polyethylene fraction (A-1) and a density of equal to or more than 910 kg/m3 to equal to or less than 960 kg/m3 with a weight ratio of (A-1) to (A-2) of 45:55 to 80:20 to form a first polyethylene resin (A) having a Mw of equal to or more than 200 kg/mol to equal to or less than 1500 kg/mol, a melt flow rate MFR5 (190° C., 5 kg) of 0.001 to 10 g/10 min and a density of equal to or more than 910 kg/m3 to equal to or less than 960 kg/m3, blending the first polyethylene resin (A) with a second polyethylene resin (B) having a Mw of equal to or more than 50 kg/mol to less than 700 kg/mol, and a density of equal to or more than 910 kg/m3 to equal to or less than 960 kg/m3 to form the multimodal polyethylene composition, wherein the multimodal polyethylene composition a melt flo…