Mobil Oil Corporation

Robert O Hagerty

John E Cook

Frederick W Jacob

Thomas E Nowlin

Per K Husby

Luanne M Allen

Richard O Mohring

Robert I Mink

Yury V Kissin

Thomas J Giacobbe

Kenneth George Schurzky

Irena B Petsche

Ahmed H Ali

Pam J Cook

A catalyst composition for copolymerizing ethylene and alpha-olefins is prepared by treating a silica carrier, in a non-polar hydrocarbon solvent, with a dialkyl magnesium compound, a halogen-containing compound and titanium tetrachloride, to form a catalyst precursor and activating the precursor with dimethylaluminum chloride. Also disclosed is a process for copolymerizing ethylene and alpha-olefins in the presence of the catalyst of the invention. The polymer products have multimodal molecular weight distributions unlike unimodal molecular weight distributions of polymers prepared with similar catalyst precursors but activated with different alkylaluminum activators, e.g., triethylaluminum or trimethylaluminum.

High activity polyethylene catalysts which produce bimodal or trimodal

A process and system for prevention of fouling of pressure taps in a first gas phase fluidized bed polymerization reactor while avoiding sheeting during production of polyolefins in a second downstream gas phase fluidized bed polymerization reactor wherein a relatively small amount of water is added directly to the pressure taps of the first reactor.

Process and system for preventing pressure tap fouling in tandem

An ethylene polymerization catalyst is prepared by impregnating a porous support, such as silica, with an organomagnesium compound such as a dialkylmagnesium compound, contacting the magnesium-containing support with a silane compound which is free of hydroxyl groups, such as tetraalkoxysilanes, e.g. tetraethyl orthosilicate, and incorporating a transition metal component, such as titanium tetrachloride, in a specific ratio to the magnesium and silane components. Activation of this catalyst precursor with dimethylaluminum chloride as a cocatalyst results in a catalyst system which is effective for the production of ethylene copolymers with multimodal molecular weight distributions.

High activity polyethylene catalysts

The invention relates to catalysts for ethylene polymerization or copolymerization to produce film quality product which exhibits improved FDA hexane extractables. The invention also relates to catalysts for ethylene polymerization or copolymerization to produce film quality product which exhibits improved dart impact resistance. The invention relates to catalysts for ethylene polymerization or copolymerization to produce film quality product which exhibits improved MD tear properties.

Catalyst composition for production of linear low-density

A catalyst composition for polymerizing alpha-olefins is prepared by reacting a transition metal compound, e.g., titanium, with trimethylaluminum catalyst activator. In a preferred embodiment, the catalyst is supported on a porous refractory support and is prepared by additionally reacting a magnesium compound or an organomagnesium composition with the support. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention. The polymer products have higher bulk density and produce films of greater strength than polymers prepared with similar catalysts utilizing different alkyl-aluminum activators, e.g., triethylaluminum and tri-isobytylaluminum.

Process for polymerizing alpha-olefins with trimethylaluminum-activated

A catalyst composition for polymerizing alpha-olefins is prepared by reacting a transition metal compound, e.g., titanium, with trimethylaluminum catalyst activator. In a preferred embodiment, the catalyst is supported on a porous refractory support and is prepared by additionally reacting a magnesium compound or an organomagnesium composition with the support. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention. The polymer products have higher bulk density and produce films of greater strength than polymers prepared with similar catalysts utilizing different alkyl-aluminum activators, e.g., triethylaluminum and tri-isobutylaluminum.

Catalyst composition for polymerizing alpha-olefins

There is provided an improvement in a method for terminating a gas phase olefin polymerization reaction with a kill gas such as carbon monoxide or carbon dioxide. The improvement involves the use of a carrier gas to increase the rate of penetration of kill gas into the reaction medium. The improved method is particularly adaptable to a fluid bed reactor system.

Reactor system for rapid kill gas injection to gas phase polymerization

Method and reactor system for rapid kill gas injection to gas phase

A catalyst composition for polymerizing alpha-olefins in a gas phase continuous process is prepared by combining a catalyst precursor with a catalyst activator in such proportions that the polymer product comprises about 9.times.10.sup.-7 to about 18.times.10.sup.-7 gram-moles of the activator per gram of the polymer produced. The use of the activator in these proportions lowers the partial pressure of the monomers used in the process without sacrificing quality of the product. The catalyst precursor is prepared by reacting a carrier having OH groups with a stoichiometric excess, with respect to the OH groups, of an organomagnesium composition, and subsequently reacting the product with a transition metal compound.

Catalyst composition for polymerizing alpha-olefins at low reactants

A fluidized bed olefin polymerization process incorporates a recycle of a vent gas, containing unreacted monomers, from the product purge bin vessel to the polymerization reactor. The recycle of the vent gas minimizes the loss of the unpolymerized reactants, thereby decreasing overall process and product costs.

Closed loop recycle of vent gas in polymerization process

Alpha-olefin polymerization catalysts are prepared by heating a solid porous carrier having reactive OH groups in the atmosphere of an oxygen-containing gas. The resulting catalysts exhibit higher productivity and produce ethylene polymers or ethylene/C.sub.3 -C.sub.10 copolymers having higher bulk density than similar catalysts prepared with the carriers heated in an atmosphere of nitrogen.

Process for preparing alpha-olefin polymers

Alpha-olefin polymerization catalysts are prepared by heating a solid porous carrier having reactive OH groups in the atmosphere of an oxygen-containing gas. The resulting catalysts exhibit higher productivity and produce ethylene polymers of ethylene/C.sub.3 -C.sub.10 copolymers having higher bulk density than similar catalysts prepared with the carriers heated in an atmosphere of nitrogen.

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Edison, NJ, United States of America

Robert O Hagerty