Phillips catalyst and its use for the preparation of ethylene homopolymers and copolymers

Abstract

A novel Phillips catalyst for the homopolymerization of ethylene and the copolymerization of ethylene with .alpha.-olefins contains, as a catalytically active component, a chromium catalyst supported on a finely divided aluminum silicate gel, modified with a fluoride and activated in an oxidizing atmosphere at elevated temperatures. The finely divided aluminum silicate gel (carrier gel) used here has an alumina content of from 0.5 to 6% by weight, the alumina being concentrated in the surface region of the carrier gel particles. The novel Phillips catalyst has high productivity and gives high molecular weight ethylene homopolymers and copolymers which have excellent low temperature impact strength and do not tend to swell in the blow molding process on emergence from the extruder die.

Dependencies are inferred from the claim text.