Olefin polymerization process

US7122606B2 · kind B2 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Maria Silvia Tonti · Ferrara, IT
• Markus Oberhoff · Speyer, DE
• Volker Fraaije · Frankfurt, DE
• Bernd Bachmann · Eppstein, DE

Key dates

• Filing date: Jun 29, 2004
• Grant date: Oct 17, 2006
• Expiry date: Jun 29, 2024

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S526/905
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for polymerizing one or more alpha-olefins of formula CH2═CHT wherein T is a hydrogen atom or a C1–C20 alkyl radical comprising the following steps: a) contacting in a continuous way one or more of said alpha olefins with a metallocene based catalyst system in a loop reactor, wherein: (i) the reaction is carried out in a liquid medium; (ii) the average residence time of the metallocene-based catalyst system is not more than 30 minutes; (iii) the temperature of the loop ranges from 25° to 70° C.; in order to obtain a polymerization degree ranging from 60 to 500 g per gram of catalyst system; b) feeding in continuous the prepolymerized metallocene-based catalyst system obtained in step a) into a polymerization reactor C) polymerizing one or more alpha-olefins, the same or different from the alpha olefins used in step a), in the presence of said prepolymerized metallocene-based catalyst system.