Broad MWD, compositionally uniform ethylene interpolymer compositions, process for making the same and article made therefrom

US6451916B1 · kind B1 · utility

Assignee

• The Dow Chemical Company Midland · US

Inventors

• Kenneth W. Anderson · Lake Jackson, US
• Pak-Wing S. Chum · Midland, US
• David A. Eversdyk · Angleton, US
• Lonnie G. Hazlitt · Lake Jackson, US
• Pradeep Jain · Lake Jackson, US
• Kalyan Sehanobish · Rochester Hills, US
• Li-Min Tau · Lake Jackson, US

Key dates

• Filing date: Aug 31, 2001
• Grant date: Sep 17, 2002
• Expiry date: Aug 31, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31938
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention pertains to a continuous process and polymerization system characterized by separate injection of catalyst and make-up feed, an ethylene interpolymer composition characterized as having broad molecular weight distribution (MWD) and optimized compositional uniformity, a process for making such a composition and a fabricated article made from such composition. The novel composition is characterized as having a melt flow ratio, I10/I2, from 8 to 30, a Mw/Mn of greater than 4 as determined by gel permeation chromatography, a melt index, I2, from 0.01 to 1000 grams/10 minutes, preferably greater that 0.1 to 10 grams/10 minutes, and a density less than 0.945 g/cm3. The novel composition exhibits good processibility and improved toughness properties, especially excellent film tear and impact resistance, and is particularly well-suited for use in applications such as high performance trash can liners and heavy duty shipping bags.