Abstract: A process for the preparation of catalysts of the polymerization of olefines, e.g. ethylene and propylene. This process comprises essentially the two following steps:(1) A compound (A) of an element selected from groups Ia, Ib, IIa, IIb, IIIa, IIIb, VIa and VIIb of the Periodic Table of Elements is heated and milled under the protection of an inert gas with an organic acetoxy compound; then the volatile portions of the mixture are eliminated by distillation.(2) The solid resulting from the first step is dissolved or dispersed in a non-polar hydrocarbon and an activator (B) is added, mixed and heated with said solution or dispersion until a homogeneous solution or dispersion of activated catalyst is obtained. (B) is selected from compounds of elements IVa, IVb and Vb of the Periodic Table. This catalyst is used in admixture with a polymerization promoter (C) selected from organo-metallic additives, e.g. aluminum-organic compounds for the polymerization of olefines at relatively low temperatures and pressures.

Abstract: A process for the preparation of catalysts for the polymerization of olefines, e.g. ethylene and propylene. This process comprises essentially the two following steps:(1) A compound (A) of an element selected from groups Ia, Ib, IIa, IIb, IIIa, IIIb, VIa and VIIb of the Periodic Table of Elements is heated and milled under the protection of an inert gas with an organic acetoxy compound; then the volatile portions of the mixture are eliminated by distillation.(2) The solid resulting from the first step is dissolved or dispersed in a non-polar hydrocarbon and an activator (B) is added, mixed and heated with said solution or dispersion until a homogeneous solution or dispersion of activated catalyst is obtained. (B) is selected from compounds of elements IVa, IVb and Vb of the Periodic Table.This catalyst is used in admixture with a polymerization promoter (C) selected from organo-metallic additives, e.g. aluminum-organic compounds for the polymerization of olefines at relatively low temperatures and pressures.

Abstract: An olefin-polymerization catalyst is prepared by reacting at least one compound of an element selected from the group consisting of the elements of groups Ia, IIa, II b, IIIa, IVa, Va and VIa of the Periodic Table of elements with at least one reactive acyl compound to provide a solid reaction product. This is dissolved or dispersed in an anhydrous non-polar organic solvent and contacted with at least one organometallic compound of a metal selected from the group consisting of elements of groups Ia, IIa, IIb, IIIa and IVa of the Periodic Table of elements and the mixture is used in an olefin polymerization reaction. The catalyst contains no transition elements.

Abstract: Olefin-polymerization catalysts having a catalytic activity much higher than related Ziegler catalysts are prepared by treating a compound of a transition element such as chromium, with at least one reagent selected from acetic acid, acetic anhydride and a chloroacetic or fluoroacetic acid, at 70.degree. to 100.degree. C for 10 to 30 hours, and treating the product, dispersed in an inert anhydrous non-polar solvent, with at least one aluminum alkyl.