Abstract: New catalysts for the polymerization of olefins and more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) a hydride or an organo-metallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with (b) the product obtained by contacting a titanium compound (1) with a mixture of an anhydrous magnesium halide (2) in a particular active form and an anhydrous compound of a metal belonging to Group I or II of said Periodic Table, (3). In the particular active form to which it is converted, during or prior to the contacting the anhydrous magnesium halide is characterized in that, in its X-ray spectrum, the diffraction line which is most intense in the X-ray spectrum of the normal, inactive magnesium halide shows a decreased intensity, and/or the active magnesium halide has a surface area greater than 3 m.sup.2 /g.

Abstract: Highly active catalysts for the polymerization of olefins are disclosed. The catalysts are prepared by mixing a hydride or organometallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with the product obtained by contacting an oxygenated Ti compound in which one or more Ti atoms are bound through oxygen atoms to organic radicals with an activated anhydrous Mg dihalide. The polymerization of ethylene by means of said catalysts is also disclosed.

Abstract: Polymerization catalysts, particularly catalysts for the polymerization of olefins, are disclosed. The catalysts are prepared by mixing hydrides of organometallic compounds of metals belonging to Groups I to III of the Mendelyeev Periodic Table with products obtained by contacting (1) titanium compounds of the formulaMpTi.sub.m X.sub.(n. m) +pin which M is an alkaline metal or the group NR.sub.4 in which the valences of the quaternary nitrogen atom are satisfied by hydrogen and/or by hydrocarbon groups or is part of a heterocyclic ring; X.sub.n. m substituents are NR.sub.2 group in which the Rs represent hydrogen, and/or hydrocarbon groups or, in part, halogen atoms; n is the titanium valence; m is a whole number from 1 to 3 inclusive; and p is zero or a whole number from 1 to 3, inclusive; with (2) carriers consisting of anhydrous Mg halides which are in active form or converted to active form by the conditions under which the carriers are contacted with the titanium compounds.

Abstract: New, highly active catalysts for the polymerization of ethylene and mixtures of ethylene with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) hydrides or organometallic compounds of metals belonging to Groups I, II or III of the Mendelyeev Periodic Table with (b) the products obtained by contacting titanium compounds with activated anhydrous halides of magnesium or manganese, diluted with anhydrous compounds of metals belonging to Groups III or IV of said Periodic Table, and which are different from either (a) or the titanium compound of (b).

Abstract: New, highly active catalysts for the polymerization of ethylene and mixtures of ethylene with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) hydrides or organometallic compounds of metals belonging to Groups I, II or III of the Mendelycev Periodic Table with (b) the products obtained by contacting titanium compounds with activated anhydrous halides of magnesium or manganese, diluted with anhydrous compounds of metals belonging to Group III or IV of said Periodic Table, and which are different from either (a) or the titanium compound of (b).