Bimodal polyethylene

US11149136B2 · kind B2 · utility

Assignee

• Univation Technologies, LLC · US

Inventors

• Nitin Borse · Lake Jackson, US
• Swapnil B. Chandak · Pearland, US
• Ayush A. Bafna · Manvel, US
• Cliff R. Mure · Fryeburg, US
• Yi Zhang · Hopkinton, US
• Timothy R. Lynn · Hackettstown, US
• Roger L. Kuhlman · Lake Jackson, US
• John F. Szul · Nitro, US

Key dates

• Filing date: Oct 25, 2017
• Grant date: Oct 19, 2021
• Expiry date: Oct 31, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2314/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Provided are various bimodal polyethylene, including but not limited to a bimodal polyethylene for a pipe having a density of from 0.9340 to 0.9470 gram/cubic centimeters (g/ccm), a melt index (12) of from 0.1 to 0.7 gram/10 minute, a melt flow ratio (121/12) of from 20 to 90. The bimodal polyethylene includes a high molecular weight polyethylene component and a low molecular weight polyethylene component which are a reaction product of a polymerization process performed in a single reactor and that employs a bimodal polymerization catalyst system. The bimodal polymerization catalyst system includes a bimodal catalyst system of bis(2-pentamethylphenylamido)ethyl)amine Zirconium dibenzyl and either (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)Zirconium dichloride or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dimethyl in a 3.0:1 molar ratio; and a trim catalyst of (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)Zirconium dichloridedimethyl in heptane added to adjust melt.