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

US6319989A · kind A · utility

Assignee

• THE DOW CHEMICAL COMPANY · 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: Jan 20, 2000
• Grant date: Nov 20, 2001
• Expiry date: Jan 20, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2205/02
• 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 compostion and a fabricated article made from such composition. The novel composition is characterized as having a melt flow ratio, I.sub.10 /I.sub.2, from 8 to 30, a M.sub.w /M.sub.n of greater than 4 as determined by gel permeation chromatography, a melt index, I.sub.2, 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/cm.sup.3. 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.