Abstract: According to the present invention, there is provided a process for preparing polyolefins which comprises polymerizing or copolymerizing olefins using as catalyst a component consisting of a solid carrier and a titanium compound and/or a vanadium compound supported thereon, and an organometallic compound, said solid carrier consisting of a product obtained by mixing and heating an aluminum oxide and an ammonium sulfate.

Abstract: Olefin polymerization catalysts are prepared by depositing a chromium compound and an aluminum compound on an inorganic support material and heating the support material in a non-reducing atmosphere at a temperature above about 300.degree. C up to the decomposition temperature of the support material. The supported chromium and aluminum compound is then combined with a metallic and/or non-metallic reducing agent, to provide a catalyst system useful in the polymerization of 1-olefins.

Abstract: The polymerization of olefins to form polymers having a molecular weight greater than 50,000 wherein the polymerization is carried out in the presence of a catalyst component formed of a compound of a transition metal of the sub-groups IVa, Va and VIa, and a co-catalyst component of at least one organo-metallic compound of a metal from groups II and III of the periodic table, in which the co-catalyst is in the form of a liquid which is separately introduced into the reaction vessel on a carrier formed of an inert porous powder which is impregnated with the co-catalyst.

Abstract: A process of polymerizing or copolymerizing a class of olefins is carried out in the presence of a catalyst, which catalyst comprises one of more solid compounds selected as a carrier from the group consisting of an oxide, a double oxide and a hydroxide of halogen-free magnesium and/or calcium. The carrier is treated by direct contact with gaseous sulfur dioxide (SO.sub.2) under a gaseous atmosphere. A titanium and/or vanadium compound, viz. Ziegler catalyst component, is deposited on the treated carrier and activated by an organometal compound.

Abstract: An olefin polymerization catalyst comprising a chromium compound deposited on a carrier, which chromium compound is complexed with a straight-chain, branched-chain, or cyclic aliphatic hydrocarbon or mixture thereof such that the mol ratio of aliphatic hydrocarbon to chromium compound is 1:2-3, said chromium compound being deposited on said carrier material in an amount between 10.sup..sup.-3 and 10 millimols chromium compound per gram of carrier material, said carrier material also containing a trialkyl, tricycloalkyl, triaryl, monohalodihydrocarbyl, or monoalkoxydihydrocarbyl aluminum compound; a process for preparing such an olefin polymerization catalyst and the use of such catalyst in the polymerization of olefins, particularly ethylene, propylene, 2-methylpropylene and butene-1.

Abstract: There are disclosed olefin polymerization catalysts based on tetra(neophyl) zirconium and its reaction products with surface-hydroxylated oxides of metals of Groups II(a), III(a), IV(a) and IV(b) of the Periodic Table of the Elements, processes for their preparation, and processes for the polymerization of olefinic monomers employing such catalysts. Neophyl zirconium aluminate supported on alumina is disclosed as the preferred, most active catalyst. The polyolefins produced are linear high polymers of high crystallinity such as polyethylene and isotactic polypropylene. Diolefins are converted into rubber by use of the process employing the catalyst. Ethylene-propylene copolymer rubbers can also be produced by use of the catalysts.

Abstract: A mixed catalyst for the low pressure polymerization of 1-olefines is prepared by reacting a chromium-III compound containing water of crystallization with a metal alcoholate and by mixing the obtained chromium complex with an activator. The catalyst excels by allowing a simple preparation method and by a very good activity.

Abstract: Olefin polymerization catalysts are prepared by depositing a chromium compound and an aluminum compound on an inorganic support material and heating the support material in a non-reducing atmosphere at a temperature above about 300.degree.C up to the decomposition temperature of the support material. The supported chromium and aluminum compound is then combined with a metallic and/or non-metallic reducing agent, to provide a catalyst system useful in the polymerization of 1-olefins.

Abstract: Essentially amorphous polyolefines of medium molecular weight are prepared by polymerization of .alpha.-olefines in the presence of a Ziegler supported catalyst. This catalyst consists of the reaction product of the chloride and/or alcoholates of the tetravalent titanium and of an alcoholate and/or a magnesium compound containing hydroxyl groups and of an aluminiumorganic compound containing chlorine, in which the proportion Al : Cl is 4:1 to 0.8:1. The polymerization is carried out at a temperature of from 100.degree. to 160.degree.C.