Vapor-phase fluidized-bed process and ethylene homopolymers and copolymers produced thereby

US6849699B2 · kind B2 · utility

Assignee

• Basell Polyolefine GmbH · DE

Inventors

• Peter Bauer · Ludwigshafen, DE
• Armin Lange · Heidelberg, DE
• Rainer Karer · Kaiserslautern, DE
• Philipp Rosendorfer · Neustadt, DE
• Manfred Hecker · Linz, DE
• Gunther Schweier · Osthofen, DE
• Wolfgang Micklitz · Neustadt, DE
• Kaspar Evertz · Schifferstadt, DE
• Hans-Jacob Feindt · Flemington, US

Key dates

• Filing date: Sep 11, 2003
• Grant date: Feb 1, 2005
• Expiry date: Sep 11, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F10/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A continuous vapor-phase fluidized-bed process for the preparation of ethylene homopolymers and copolymers having a density of from 0.87 to 0.97 g/cm3 in which ethylene or mixtures of ethylene and C3-C8 a-monoolefins are (co)polymerized in the presence of a supported chromium catalyst in the polymerization zone of a vapor-phase fluidized-bed reactor under pressures ranging from 1 to 100 bar and at temperatures ranging from 30° to 125° C. in the vapor phase in an agitated bed of bulk material comprising particulate polymer, the resultant heat of polymerization is removed by cooling the recirculated reactor gas and the resulting (co)polymer is removed from the vapor-phase fluidized-bed reactor, wherein, for the preparation of a (co)polymer of a specific density d, the (co)polymerization is carried out at a temperature which is in a range restricted by an upper envelope defined by equation I and a lower envelope defined by equation II in which the variables have the following meanings: