Abstract: A process comprising continuously contacting with a catalyst, under polymerization conditions, ethylene or a mixture comprising ethylene and one or more alpha-olefins in a first fluidized bed reactor and a mixture comprising ethylene and one or more alpha-olefins in a second fluidized bed reactor, the first and second reactors being connected in series, said catalyst comprising:(A) a catalyst precursor comprising:(i) a vanadium compound, which is the reaction product of(a) VX.sub.3 wherein each X is independently chlorine, bromine, or iodine; and(b) an electron donor, which is a liquid, organic Lewis base in which VX.sub.3 is soluble;(ii) a modifier having the formula BX.sub.3 or AlR.sub.(3-a) wherein each X is as defined above; each R is independently alkyl having 1 to 14 carbon atoms; and a is 1 or 2; and(iii) a silica or alumina support for said vanadium compound and modifier;(B) a cocatalyst having the formula AlR.sub.3 wherein R is as defined above; and(C) a promoter having the formula R'.sub.b CX'.sub.

Abstract: A process comprising contacting a mixture comprising ethylene, propylene, and, optionally, a diene, in the gas phase, under polymerization conditions, with a catalyst system comprising:(a) a catalyst precursor, in independent or prepolymer form, consisting of vanadium (acetylacetonate).sub.3 ;(b) optionally, a support for said precursor;(c) a cocatalyst consisting essentially of (i) an alkylaluminum halide having the formula AlR.sub.(3-a) X.sub.a wherein each R is independently alkyl having 1 to 14 carbon atoms; each X is independently chlorine, bromine, or iodine; and a is 1 or 2, and (ii) optionally, a trialkylaluminum provided that the molar ratio of alkylaluminum halide to trialkylaluminum is at least about 1.

Abstract: A process for the production of EPRs comprising contacting ethylene, propylene, and optionally, a diene, under polymerization conditions, with a catalyst system comprising:(A) a catalyst precursor comprising:(i) a vanadium compound, which is the reaction product of(a) VX.sub.3 wherein each X is independently chlorine, bromine, or iodine; and(b) an electron donor, which is a liquid, organic Lewis base in which VX.sub.3 is soluble;(ii) a modifier having the formula BX.sub.3 or AlR.sub.(3-a) X.sub.

Abstract: A vanadium-based catalyst system is treated with an ether as a means of enhancing catalyst activity and polymer productivity.

Abstract: A process for the production of polyethylene comprising contacting ethylene or a mixture comprising ethylene and one or more alpha-olefins and, optionally, one or more diolefins, under polymerization conditions, with a catalyst system comprising:(a) a particulate catalyst precursor based on titanium or vanadium;(b) polypropylene support particles to which the catalyst precursor particles are bonded; and(c) a hydrocarbyl aluminum cocatalyst.

Abstract: A vanadium-based catalyst system is treated with an aluminum alkoxide as a means of enhancing catalyst activity and polymer productivity.

Abstract: A vanadium-based catalyst system is treated with a boron alkoxide as a means of enhancing catalyst activity and polymer productivity.

Abstract: An improved support vanadium catalyst, especially an improved Beran et al. catalyst system and ethylene polymerization process in which the improvement derives from fixing the promoter to a component of the catalyst composition such that it is a molecularly structural component of the catalyst and thus is not separately fed to the polymerization reaction, but instead is part of the catalyst composition fed to the reaction.

Abstract: An ethylene polymerization catalyst comprising a supported precursor of vanadium trihalide/electron donor complex and alkylaluminum or boron halides, when combined with alkylaluminum cocatalyst and alkyl halide promoter, provides enhanced polymerization and productivity plus superior polyethylene.

Abstract: A vanadium-based catalyst is treated with certain oxygen-containing compounds as a means of narrowing and effectively regulating the molecular weight distribution of the polymers produced with the catalyst.

Abstract: A vanadium catalyst composition comprising:(i) the reaction product of a vanadium compound and an electron donor, which is a liquid, organic Lewis base in which the vanadium compound is soluble;(ii) a hydrocarbyl aluminum cocatalyst; and(iii) a promoter having the following formula:C.sub.3 (X).sub.a (F).sub.b (H).sub.

Abstract: A process for producing copolymers of ethylene and butene-1 wherein the butene-1 comonomer is generated in situ within the polymerization reactor by a separately catalyzed ethylene dimerization reaction.

Abstract: A vanadium-based catalyst is treated with certain oxygen-containing compounds as a means of narrowing and effectively regulating the molecular weight distribution of the polymers produced with the catalyst.

Abstract: A process for activating a titanium or vanadium compound and producing polyethylene comprising (i) dissolving a divalent magnesium halide and a Lewis acid having the formula R.sub.m A1X.sub.n or R.sub.m BX.sub.

Abstract: A process for activating a titanium or vanadium compound and producing polyethylene comprising (i) dissolving a divalent magnesium halide and a Lewis acid having the formula R.sub.m A1X.sub.n or R.sub.m BX.sub.

Abstract: An ethylene polymerization catalyst comprising a supported precursor of vanadium trihalide/electron donor complex and alkylaluminum or boron halides, when combined with alkylaluminum cocatalyst and alkyl halide promoter provides enhanced polymerization and productivity plus superior polyethylene.