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

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

Abstract: Stereoregular polymers having a molecular weight distribution of less than 5.0 and an isotactic index in excess of 96 percent are produced by polymerizing an alpha-olefin having 3 to 8 carbon atoms in a low pressure gas phase fluid bed process at a temperature in excess of 80.degree. C. employing a heat stable catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halide and a polycarboxylic acid ester containing two coplanar ester groups attached to adjacent carbon atoms, as inside electron donor, (b) an organoaluminum cocatalyst, and (c) a silicon compound containing a silicon-oxygen-carbon linkage, as outside electron donor.

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

Abstract: A supported, electron donor-complexed reduced vanadium.sup.(<3) /zirconium coimpregnated catalyst possessing enhanced activity, the methods of its manufacture and ethylene polymers of broad molecular weight distribution produced therewith.

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: Ethylene copolymers having a very low molecular weight are continuously prepared in a fluidized bed in the presence of reduced concentrations of hydrogen, at improved catalyst activity and polymer productivity, by effecting polymerization in the presence of a dialkylzinc compound.

Abstract: Ethylene homopolymers or copolymers having a very low molecular weight are continuously prepared in a fluidized bed in the presence of high concentrations of hydrogen, while maintaining high catalyst activity, by means of a vanadium-based catalyst.

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

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

Abstract: Catalyst compositions suitable for producing high density ethylene polymers in a low pressure gas phase process with low accompanying ethylene hydrogenation are produced by forming a precursor composition from a magnesium compound, titanium compound and electron donor compound; diluting said precursor composition with an inert carrier material; treating said diluted precursor compositon with a boron halide compound; and activating the precursor composition with an organo aluminum compound.

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

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

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: Highly stereospecific olefin polymers are obtained in enhanced yield in a continuous gas-phase fluid bed process for polymerizing alpha monoolefins employing a catalyst system comprising (a) a solid titanium-containing procatalyst, (b) an organoaluminum activator compound, and (c) a selectivity control agent, by continuously adding dialkylaluminum halide to the reactor during polymerization and conducting polymerization at a temperature of 0.1.degree. to 5.0.degree. C. above the dew point temperature of the cycle gas in the reactor.

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-based catalyst is treated with certain phosphorus-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 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 method for smoothly and reliably initiating polymerization of ethylene with a supported chromium oxide catalyst, with smaller amounts of catalyst and in substantially shorter periods of time then heretofore required, by adding an alkylaluminum compound and a hydroxyl-containing compound to the reactor of a polymerization reaction system prior to the commencement of polymerization and subjecting said alkylaluminum compound and hydroxyl-containing compound to suitable conditions of temperature and pressure for a time sufficient for said alkylaluminum compound to react completely with the moisture present in said reactor and said hydroxyl-containing compound.