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4719193 Processes for preparing polyethylene catalysts by heating catalyst precursors  
Ethylene polymers are obtained in enhanced yield in a process for homopolymerizing ethylene or copolymerizing ethylene with an alpha-olefin having 3 to 8 carbon atoms employing a catalyst system...
4716205 Nickel-catalyzed polymerization of ethylene  
Preparation of polyethylene in the presence of selected nickel-containing catalysts.
4713430 Preparation of ethene polymers by means of a Ziegler catalyst system  
Finely divided ethene polymers are prepared by means of a Ziegler catalyst system composed of (1) a titanium-containing catalyst component obtained by precipitation in an organic liquid from (1.1)...
4707530 Polymerization catalyst  
Ethylene is homopolymerized or copolymerized with another olefin monomer in the presence of a catalyst system comprising organo metal cocatalyst and a titanium-containing catalyst component, said...
4705714 Differentially crosslinked and oriented polyethylene film  
An oriented film is prepared by crosslinking a sheet of HDPE to provide maximum crosslinking at the surfaces of the sheet and minimum orientation at its middle layer portion, and thereafter heating...
4699961 High efficiency catalysts for varying olefin polymer molecular weight distribution  
Catalysts having high efficiency in preparing olefin polymers while controlling molecular weight distribution are disclosed. The catalysts utilize magnesium siloxide supports and the product...
4692501 Process for continuous multi-stage polymerization of olefins  
In a process for producing an olefin polymer which comprises continuously polymerizing an olefin in the presence of a catalyst composed of a transition metal compound component and an...
4690800 Process for reducing the chances of ignition and explosion due to the decomposition of high-pressure industrial process gases  
The danger of explosion due to decomposition of high-pressure industrial process gases, such as ethylene, is reduced by beginning to cool the decomposition gases with a delay of no more than 25...
4686265 Process for polymerization of olefins  
A process for polymerizing one or more alpha-olefins in the presence of a catalyst system comprising (A) a solid titanium containing catalyst component said component prepared by contacting a...
4675368 Process for inhibiting crust formation in reactors during alpha-olefin prepolymerization modification of Ziegler catalyst  
Process for inhibiting crust formation in reactors used for polymerising alpha-olefines, such as ethylene and propylene, in the presence of particles of catalytic solids containing titanium and...
4673719 Process for producing olefin polymers and catalyst composition therefor  
In a process for producing olefin polymers or copolymers which comprises polymerizing olefins or copolymerizing olefins with each other or with dienes in the presence of [A] a solid titanium...
4672096 Catalyst composition for polymerizing alpha-olefins  
A catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier containing OH groups with an organomagnesium composition and contacting the thus-formed magnesium-containing...
4668577 Polyethylene filaments and their production  
Crosslinked polyethylene filaments made of polyethylene having an average molecular weight of not less than 4×10 5 , which are stretched and crosslinked by irradiation of radioactive rays and have...
4657998 Polyethylene with broad molecular weight distribution  
Catalyst system comprising titanium containing catalyst component, isoprenylaluminum and a halohydrocarbon for the production of polyethylene having a broad molecular weight distribution.
4657996 Process for producing polyethylene  
A process for producing polyethylene comprises polymerizing ethylene or copolymerizing ethylene with other α-olefin in the presence of a catalyst system obtained by bringing the following...
4650842 Olefin polymerization process employing catalyst prepared from high pore volume, high purity alumina gel  
Novel high pore volume, high purity alumina gels and catalysts prepared therefrom are provided by a unique alumina gel preparation comprising hydrolyzing an aluminum alcoholate in a medium of a...
4649182 Polymerization catalysts and methods of preparation thereof  
The catalysts are composed of an organometallic compound and a solid catalytic component which is the reaction product of a transition metal derivative and a solid support having a composition, at...
4627962 Process and apparatus for reducing the chances of ignition and explosion from the decomposition of high pressure industrial process ethylene gases  
An apparatus for evacuating the gases resulting from the decomposition of industrial process gases, such as ethylene, contained in a vessel under high pressure is adjacent to the vessel. The...
4621124 Catalyst system for the polymerization of ethylene  
A catalyst system for use in the polymerization of ethylene under high pressure and temperature containing an alkyl-aluminum or alkylsiloxalane activator and a compound of the formula: (TiCla)...
4618661 Supported high efficiency polyolefin catalyst component and methods of making and using the same  
A supported high efficiency catalyst component for polyolefin production and methods of making and using the same are disclosed. A catalyst support made from a solid, particulate support material,...
4617361 Process and catalyst for olefin polymerization  
A process and catalyst for the polymerization of olefins wherein the catalyst is prepared by reacting scandium, yttrium or rare earth metal halides with certain transition metal compounds, reacting...
4617360 Process for the polymerization of α-olefins  
Catalyst systems for the polymerization of α-olefins, as well as process for making and using the same, which comprises an organometallic compound, like an organoaluminum compound, and a solid...
4613655 Catalysts for the polymerization of olefins  
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...
4607086 Continuous process for the manufacture of low-density polyethylene in stirred autoclaves  
An improved continuous process for the manufacture of polymers of ethylene in autoclave reactors with practically complete back-mixing under pressure of from about 800 to about 2500 bars in the...
4605715 Process for polymerizing olefins in the presence of a catalyst prepared from organomagnesium compound, epihalohydrin reducing halide source and transition metal compound  
Olefins are polymerized in the presence of, as a catalyst therefor, the catalytic reaction product resulting from heating a mixture of (A) at least one hydrocarbon soluble organomagnesium...
4603183 Hydrocarbon soluble catalyst supports and resultant polymerization catalysts  
A method is provided for preparing hydrocarbon soluble magnesium siloxide supports comprising contacting such supports with sufficient aluminum alkoxide or organic ethers to render the supports...
4600633 Polyethylene superthin film and a process for the production of the same  
A polyethylene superthin film having a thickness of at most 3 μm, a tensile modulus of at least 2000 kg/cm 2 , a breaking strength of at least 500 kg/cm 2 and a haze of at most 10% is produced by...
4597818 Method for producing laminated sheets or films  
A novel method for producing laminated sheets or films consisting of a substrate layer or layers and a layer or layers of ultra-high molecular weight polyethylene. The method is characterized by...
4596862 Olefin polymerization using chromium on fluorided aluminophosphate  
Ethylene polymer is particularly suitable for the production of tough film is produced under slurry conditions using a fluorided aluminophosphate support and a reaction temperature within the range...
4595735 Catalyst component for polymerization of olefins  
A catalyst component for the polymerization of olefins and particularly ethylene which is prepared by contacting a contact product of a magnesium alkoxide, a halogenated hydrocarbon, a halogenated...
4587227 Ethylene polymers and chromium catalysts  
Olefin polymerization catalysts are described which are based on solid inorganic oxides (such as silica) and polychromium complexes (such as octakis(μ-trimethylsilylmethyl)tetrachromium(II))....
4587163 Preparation of ultra high molecular weight polyethylene morphologies of totally fused particles with superior mechanical performance  
An isotropic semicrystalline morphology of ultra-high-molecular-weight polyethylene and a method of making it. An original powder stock or a partially fused, melt-crystallized stock having a...
4585839 Catalyst containing an aromatic silicon compound for the polymerization of ethylene  
A catalyst for the polymerization of ethylene comprising at least one halogenated compound of a transition metal of Groups IV to VI of the Periodic System and at least one aromatic silicon compound...
4579833 Process for the preparation of a supported catalyst based on vanadium compounds for the polymerization and copolymerization of ethylene and the catalysts obtained thereby  
New catalysts which can be used for the polymerization and copolymerization of ethylene, comprising a support consisting basically of magnesium chloride on which is deposited by precipitation a...
4579757 Plastic containers for use in packaging and thermal processing of comestibles  
Off-flavor development is alleviated, or substantially minimized, in thermally processed comestibles packed in plastic containers. The container wall which is in contact with the comestibles is...
4569975 Polymerization of olefins in presence of a catalyst prepared from organomagnesium compound, carbon dioxide compound, reducing halide source and transition metal compound  
Olefins or mixtures thereof are polymerized in the presence of the product resulting from heating in an inert hydrocarbon diluent a mixture of (A) an organomagnesium material, (B) essentially...
4567243 Polymerization method  
A catalyst and method in which the catalyst is active with a cocatalyst in the polymerization and copolymerization of 1-olefins and is prepared by reacting together one or more of a specific class...
4560733 Polymerization and catalyst  
Polymerization of olefins in the presence of a catalyst system comprising titanium-coating component (A) associated with a milled blend of at least two different silica-containing components having...
4559394 Olefin polymerization using activated chromium catalyst treated with tertiary alcohol  
A catalyst is produced by contacting an already activated silica-titania supported chromium composition with a tertiary alcohol and thereafter reactivating under relatively mild conditions. Such...
4552937 Polymerization catalyst system  
Novel silicon-aluminum compounds having at least two aryl-silicon bonds useful as cocatalysts for a catalyst system for polymerizing olefins.
4547557 Silica-titania cogel from two-step hydrolysis  
A silica-titania cogel is produced in a two-step process wherein in the first step an alkyl polysilicate and/or a tetraalkyl silicate is partially hydrolyzed in an alkaline organic solvent using...
4547479 Polyphosphate in chromium catalyst support  
A catalyst support based on aluminum polyphosphate or polyphosphoric acid-impregnated alumina is provided by two alternative techniques. In the first embodiment, an aluminum polyphosphate...
4544762 Process for the preparation of oligomeric aluminoxanes  
The present invention relates to a process for the preparation of oligomeric alkylaluminoxanes of the general formulae: ##STR1## in which R=C 1 -C 6 -alkyl, preferably methyl, and n=2-40,...
4543296 Conductive polymers  
Disclosed is a method of making a conductive polymer from a non-aromatic ethylenically unsaturated gaseous monomer comprising bombarding an inert substrate with the monomer at a velocity greater...
4542197 Polymerization catalyst  
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...
4540757 Polymerization and catalyst  
Polymerization of olefins in the presence of a catalyst system comprising titanium-containing component (A) associated with a milled blend of at least two different silica-containing materials...
4540758 Polymerization of ethylene with supported π allyl chromium complexes  
A process for the polymerization or copolymerization of an olefinically unsaturated monomer which comprises contacting the monomer with a chromium metal catalyst composition which is the product...
4536550 Polyethylene composition  
A polyethylene composition comprising three specific types of polyethylenes; polyethylene (A), polyethylene (B) and polyethylene (C) respectively. The polyethylene composition has a melt index not...
4535134 Method and apparatus for controlling the discharge of product from vapor phase polymerization of monomers in a horizontal stirred-bed reactor  
A method and apparatus are disclosed for metering the removal of polymer or copolymer from the take-off end of a horizontal vapor phase polymerization stirred-bed reactor. The take-off zone...
4533706 Catalyst and process using same for producing olefin polymer  
A catalyst system for the polymerization of olefins which comprises; (A) a hydrocarbyloxy group-containing solid catalyst component prepared by (i) reducing a titanium compound represented by...