Exxonmobil Chemical Patents Inc.

Stanley J Katzen

Anthony Nicholas Speca

Zerong Lin

Scott Thomas Roger

Thomas W Towles

James Austin Kendrick

Donna Jean Crowther

Robert Tan Li

David H McConville

Arnold Lustiger

Thomas T Sun

Edward F Smith

Jeanne Marie MacDonald

Disclosed are polyethylene ('PE') compositions, articles comprising PE compositions, and methods of making blended PE compositions, wherein the blended composition comprises from about 80 to about 95 weight % of a first PE and from about 5 to about 20 weight % of a second PE. The first PE has a density greater than or equal to about 0.945 g/cc and a MWD greater than about 5. The second PE has a density less than about 0.945 g/cc, a melt index less than about 0.70 g/10 minutes and less than or equal to the melt index of the first PE, a MWD ranging from about 1 to about 5, a weight average molecular weight less than about 400,000, and a CDBI greater than about 50%. The PE composition has an ESCR greater than the ESCR of the first PE.

Enhanced ESCR of HDPE resins

The present invention relates to the removal of hydrocarbon residues from a catalyst and more specifically the air activation of a catalyst containing hydrocarbon residues. It also relates to extruded pipe and utility conduit resins comprising polyethylene, household/industrial chemicals container resins, and to a polyethylene resin particularly suitable for large parts by blow molding and sheet extrusion procedures, wherein the resin is made by a process using an activated chromium and titanium-based catalyst.

Catalyst activation and resins therefrom

Methods of making supported chromium catalyst systems and processes of polymerizing ethylene using the supported chromium catalyst systems are disclosed. A method of forming a catalyst system in a polymerization reactor includes contacting a supported chromium catalyst and a metal alkyl cocatalyst by cofeeding the catalyst and cocatalyst to the reactor or feeding the catalyst and cocatalyst separately to the reactor, to form a catalyst system. The catalyst and cocatalyst are not pre-contacted prior to the feeding or cofeeding step. The catalyst system can be contacted with ethylene and optional alpha-olefin comonomer to form polyethylene.

Catalyst system and process

This invention relates to a method of preparing a supported catalyst comprising the steps of contacting a solid titanium with a supported catalyst compound, and heating the combination to at least 150&#xb0; C.

Method of preparing a treated support

A method for polymerizing ethylene is provided. The method can include preparing a supported catalyst composition comprising the steps of: (a) dehydrating a chromium impregnated support; (b) at least partially dissolving a titanium-containing compound in one or more inert solvents to provide a solution comprising the titanium-containing compound; (c) contacting the dehydrated chromium impregnated support with the titanium-containing solution to provide a mixture comprising the solvent, titanium-containing compound and chromium impregnated support; (d) removing the solvent from the mixture; and (e) activating the product of step (d) at a temperature of at least 800&#xb0; F. (427&#xb0; C.) to provide a supported titanated chrome catalyst composition. The supported titanated chrome catalyst composition can be feed to a slurry reactor, and contacted with an optional co-catalyst, under polymerization conditions, with ethylene.

Method for catalyst preparation and improved polyethylene blow molding resin

This invention relates to a method to polymerize olefins comprising contacting a solid aluminum or solid titanium compound with a supported catalyst compound, heating the solid aluminum or solid titanium compound to cause the solid compound to vaporize, optionally activating the support by oxidation, thereafter contacting the activated support with one or more olefin monomers.

This invention relates to a method of preparing a supported catalyst comprising the steps of contacting a solid titanium or solid aluminum compound with a supported catalyst compound, and heating the combination to at least 150&#xb0; C.

Polymerization processes are disclosed for producing polyethylene having a target density and improved environmental stress resistance. Ethylene and optionally one or more &#x3b1;-olefin comonomers, supported chromium catalyst, and metal alkyl cocatalyst are contacted to produce polyethylene. The density of the polyethylene is determined, and the concentration of cocatalyst is adjusted in response to a deviation between the density of the polyethylene and the target density. The catalyst and cocatalyst can be fed separately into the reactor, or can be co-fed, eliminating the need to pre-contact the catalyst and cocatalyst prior to introducing them into the reactor.

Polymerization process

An olefin polymerization catalyst system, comprising a catalyst represented by the general formula CrR , wherein each R is independently a hydrocarbyl or substituted hydrocarbyl, with the proviso that R may not be a cyclopentadienyl group, an activator represented by the general formula, MQ , where M is a Group II metal, where each Q is independently an alkyl, or substituted alkyl; and a support. The support may be organic or inorganic. Ethylene and one or more olefins may be polymerized by the catalyst system.

Growing community of inventors

Baton Rouge, LA, United States of America

Stanley J Katzen