Multistage process for producing polyethylene compositions

US9708479B2 · kind B2 · utility

Assignee

• Borealis AG · AT

Inventors

• Thomas Hjertberg · Kungshamn, SE
• Ravindra Tupe · Mumbai, IN
• Udo Wahner · Linz, AT
• Tanja Piel · Linz, AT
• Yi Liu · Linz, AT
• Alexandra Romina Albunia · Linz, AT
• Floran Prades · Linz, AT
• Joseph Thorman · Houston, US
• Dusan Jeremic · Calgary, CA

Key dates

• Filing date: Sep 24, 2014
• Grant date: Jul 18, 2017
• Expiry date: Sep 24, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2205/03
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for polymerizing ethylene in the presence of a polymerization catalyst by copolymerizing ethylene with a comonomer selected from the group of C4-C10 alpha-olefins in three polymerization stages. The polymers produced in the three stages have different melt flow rates. The polymer composition produced by the process has good mechanical properties and can be used for making pipes. The process has a good productivity and provides a stable and economic operation.