Process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins

US5310712A · kind A · utility

Assignee

• BASF SE

Inventors

• Guido Funk · Worms, DE
• Rainer Hemmerich · Havelsee, DE
• Hans Gropper · Schifferstadt, DE
• Erich Kolk · Bad Dürkheim, DE
• Godofredo Follmer · Frankenthal (Pfalz), DE

Key dates

• Filing date: Sep 30, 1992
• Grant date: May 10, 1994
• Expiry date: Sep 30, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F10/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

In a novel process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, a carrier gel (1) is first prepared by a method in which a sodium or potassium waterglass solution is introduced into a stream of an aqueous mineral acid which is subjected to angular momentum and may contain aluminum ions, longitudinally and tangentially to the stream, the resulting silica hydrosol sprayed in the form of drops into a gaseous medium and allowed to solidify into a hydrogel, and the resulting hydrogel is freed from salts by washing without prior aging and, if necessary, freed from some of the water by extraction with alcohols and/or ketones and is then dried. This gives the carrier gel (1), which is milled and is fractionated according to particle size. In a second process step, the carrier gel (1) is laden with chromium trioxide or with a chromium compound which can be converted into chromium trioxide, after which the resulting chromium-containing carrier gel (2) is heated at from 400.degree. to 1100.degree. C. for from 10 to 1,000 minutes in an anhydrous gas stream containing oxygen in a concentration of more than 10% by volume. In the novel process, it is esse…