Abstract: Alumina-supported halogen-containing transition metal compounds prepared in such manner that (a) the transition metal compound is chemically bound to and supported by an activated alumina having a high surface area and an internal pore volume greater than 0.8 cc/g., (b) the concentration of the transition metal compound chemically bound to the support is greater than 10 grams of transition metal per kilogram of activated alumina, and (c) the atom ratio of halogen to transition metal on the support is higher than that of the halogen-containing transition metal compound which is used and preferably greater than 3:1, have been found to be unusually effective cocatalysts for the polymerization of ethylene and other .alpha.-olefins. These supported cocatalysts, which may be used to produce polyethylene as well as interpolymers of ethylene with other .alpha.-olefins and with diolefins, are prepared by heating an alumina hydrate (such as boehmite) to a temperature in the range from about 500.degree. C. to 900.

Abstract: This invention relates to novel catalysts and cocatalysts for use in the polymerization and copolymerization of .alpha.-olefins, to a process of using such catalysts to polymerize and copolymerize .alpha.-olefins, and to a process of making such cocatalysts. The .alpha.-olefins are polymerized or copolymerized in the presence of a catalytic amount of a catalyst comprising an organometallic compound of a metal of Groups I a, II a, II b, III a, or IV a of the Periodic Table and a cocatalyst comprising the reaction product of an activated halogenated alumina having an atomic ratio of halogen/aluminum of from 0.1 to 1 and a derivative of a transition metal.

Abstract: This invention relates to novel catalysts and cocatalysts for use in the polymerization and copolymerization of .alpha.-olefins, to a process for using such catalysts to polymerize and copolymerize .alpha.-olefins, and to the process of making such cocatalysts. The .alpha.-olefins are polymerized or copolymerized in the presence of a catalytic amount of a catalyst system comprising an organometallic compound of a metal of Groups Ia, IIa, IIb, IIIa, or IVa of the Periodic Table and a cocatalyst comprising the reaction product of a halogenated alumina and a derivative of a transistion metal of Groups IVb, Vb, and VIb of the Periodic Table, said halogenated alumina being formed by halogenating a complex oxide of aluminum and at least one other metal.