Activation of supported chromium oxide catalysts

Abstract

A method for activating supported chromium oxide catalysts in which a dry catalyst of inorganic or organic chromium compound dispersed on a silica-containing substrate (1) is contacted with a normally liquid organic aliphatic hydroxy compound, preferably at or above the boiling point of the hydroxy compound and (2) is reduced in a carbon monoxide containing environment and the reduced composition is reoxidized in an oxygen-containing environment to produce an activated catalyst. Steps (1) and (2) may take place in the opposite order, but both are necessary. A method for producing polymers of ethylene in which ethylene monomer, and suitable comonomer when used, are contacted at polymerization conditions in the presence of a catalyst activated by the method described above.

Dependencies are inferred from the claim text.