Supported chromium-containing catalyst and process of polymerizing

Abstract

A catalyst and the method of making same and a method of making polymers of 1-olefins with said catalyst in which the catalyst is prepared by dispersing on a finely divided, difficultly reducible, inorganic support of the nature of silica, alumina, thoria, zirconia, titania, magnesia and mixtures thereof, a chromium chelate derived from a beta-dicarbonyl compound that may be either acyclic or cyclic, the chelate being essentially of the formula ##EQU1## wherein R is individually selected from hydrogen, alkyl, alkenyl, aryl, cycloalkyl and cycloalkenyl radicals and combinations of these radicals with each R containing 0-20 carbon atoms and a corresponding valence-satisfying number of hydrogen atoms, R' is selected from alkylene, alkenylene, arylene, cycloalkylene and cycloalkenylene radicals and combinations of these bivalent radicals with R' containing 1-20 carbon atoms and a corresponding valence-satisfying number of hydrogen atoms, m is a whole number of 1 to 3, n is a whole number of 0 to 2 and m plus n is 2 or 3 and X is an inorganic or organic negative group (relative to chromium) such as halide, alkyl, alkoxy and the like, followed by activating the mixture of the supportt and chromium chelate by heating at an elevated temperature in a non-oxidizing (either inert or reducing) atmosphere. Typical compounds are chromium acetylacetonate, chromium benzoylacetonate, chromium 5,5-dimethyl-1,3-cyclohexanedionate, chromium 2-acetylcyclohexanonate, and the like.