Equistar Chemicals, LP

Mark P Mack

Sandor M Nagy

Clifford C Lee

Shaotian Wang

Barbara M Tsuie

Jean A Merrick-Mack

Charles S Holland

Philip J Garrison

Edward S Vargas

Bradley P Etherton

Jia-Chu X Liu

Natalia Nagy

Paula L Nygard

Michael W Lynch

Gregory G Hlatky

Leonard V Cribbs

Venki Chandrashekar

James H Meas

Debra L Beran

Lawrence R Wallace

Charles H Gates, Jr

James H Meas, Jr

Everett O Lewis

Joel A Mutchler

Shao-Hua Guo

Maged G Botros

Harilaos Mavridis

Craig C Meverden

Sameer D Mehta

Linda N Winslow

D Ryan Breese

Karen L Neal-Hawkins

Kenneth W Johnson

Anil W Saraf

James Ronald Clark

Kelly L Williams

Jia-Chu Liu

A method of modifying a tubular low density polyethylene (LDPE) is disclosed. In the method ethylene is polymerized with a free radical initiator in a high pressure reactor to form an LDPE. The LDPE is then reacted with a free radical initiator to produce a modified polyethylene. The modified polymer has an increased long chain branching index as indicated by the increase in the gel permeation chromatography branching index.

Modifying tubular LDPE with free radical initiator

A method for making multilayer thin films is disclosed. The method of comprises orienting a thick multilayer film in the machine direction at a drawdown ratio effective to produce a multilayer thin film. The thick multilayer film has a thickness within the range of 1 mil to 5 mils and comprises at least one layer of a linear low density polyethylene (LLDPE) and at least one layer of a high density polyethylene (HDPE) or a medium density polyethylene (MDPE).

Preparation of multilayer polyethylene thin films

Disclosed is a polyethylene composition. The composition comprises single-site multimodal resin A and single-site multimodal resin B, wherein resin A differs from resin B in molecular weight, in monomeric composition, in density, in long chain branch concentration or distribution, or in combinations thereof. Disclosed is also a method for making the polyethylene composition. The method comprises polymerizing, in the presence of two or more single-site catalysts, ethylene or its mixture with a C-C&#x3b1;-olefin to form a first multimodal resin and continuing the polymerization in the presence of the same catalysts but in a different hydrogen concentration, in a different monomer composition, or at a different temperature to form a second multimodal resin.

Preparation of multimodal polyethylene

A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of an &#x3b1;-olefin, hydrogen, and a catalyst comprising an activator and a supported, dimethylsilyl-bridged bis(indenoindolyl)zirconium complex. The process has high catalyst activity and produces polyethylene having a broad molecular weight distribution.

Olefin polymerization process

An ethylene polymerization process is disclosed. Ethylene is polymerized in two slurry reaction zones with a C-Calpha-olefin in the presence of a single-site catalyst capable of making a high molecular weight polyolefin. The process yields medium density and linear low density polyethylene having a bimodal molecular weight distribution and a melt index from about 0.10 to about 0.80. Films from the polyethylene have superior impact properties.

Polyethylene process

Methods for making polyolefins are disclosed. One method comprises polymerizing an olefin in the presence of a catalyst system comprising a single-site complex, an agglomerated metal oxide/clay support-activator, and an ionic borate. Including an ionic borate with the support-activator provides an unexpected boost in catalyst activity and gives polyolefins with high molecular weight and improved comonomer incorporation. In another method of the invention, an olefin is polymerized in the presence of an indenoindolyl metal alkylated complex and an agglomerated metal oxide/clay support-activator. Use of alkylated indenoindolyl complexes with the support-activators provides improved activity compared with metal halides.

Olefin polymerization methods

Resins comprising a relatively high-density, low-molecular-weight polyethylene component and a relatively low-density, high-molecular-weight ethylene copolymer component and methods of making the resins are disclosed. The rheological polydispersity of the high-density component exceeds that of either the resin or the low-density component. The resins are valuable for making films, sheets, coatings, pipes, fibers, and molded articles having a favorable balance of good stiffness and excellent environmental stress crack resistance.

Polymer resins with improved environmental stress crack resistance

A high-temperature solution process for polymerizing ethylene is disclosed. The polymerization is performed in the presence of a preassembled bimetallic Ziegler-Natta catalyst and an aluminum compound. Molecular modeling calculations predict that the bimetallic Ziegler-Natta catalyst will have good activity and improved stability versus traditional Ziegler-Natta catalysts. This makes the catalyst especially suitable for solution polymerization processes, which require a thermally robust catalyst.

Solution polymerization process utilizing preassembled bimetallic Ziegler-Natta catalyst

The present invention provides a non-metallocene catalyst comprising a complex having one or more ligands coordinated a transition metal. The catalyst contains substituents bonded to the transition metal through a heteroatom such as oxygen or sulfur. Furthermore, the complex includes a Group 3 to 10 transition or lanthanide metal and one or more anionic or neutral ligands in an amount that satisfies the valency of the metal such that the complex has a net zero charge. The present invention also discloses a method for preparing the catalyst and polymerizing olefins utilizing the catalyst of the present invention.

Catalysts containing at least one heterocyclic ligand for improving the catalysts' performance of olefin polymerization

Improved multi-phase polypropylene composites are provided. The compositions are comprised of a polypropylene base resin, a non-compatible dispersed phase which can be a polymer or filler material and a propylene-ethylene copolymer grafted with a carboxylic acid or carboxylic acid derivative.

Multi-phase polypropylene compositions

A new class of zwitterionic metallocycles is disclosed. A positively charged Group 4-10 transition metal is chelated to two heteroatoms and one of the heteroatoms has a substituent bearing a negative charge. We have found that substitution in this position stabilizes the zwitterion form of the metallocycle. The zwitterionic metallocycle is useful for olefin polymerizations.

Zwitterionic Metallocycles

A method for making ethylene polymers and copolymers is disclosed. The method uses a catalyst system comprising a low level of an aluminum-containing activator, a bridged indenoindolyl transition metal complex, and a treated silica support. The method enables economical preparation of ethylene copolymers having very low density. The silica-supported, bridged complexes incorporate comonomers efficiently and are valuable for a commercial slurry loop process. Use of a bridged indeno[2,1-b]indolyl complex provides exceptionally efficient comonomer incorporation, and gives polymers with a substantial and controlled level of long-chain branching. The method facilitates the production of a wide variety of polyolefins, from HDPE to plastomers.

Method for making polyolefins

A process for making olefin-acrylic copolymers is disclosed. The process comprises polymerizing an olefin and an acrylic monomer in the presence of an activator and a Group 8-10 late transition metal complex. The late transition metal catalyst contains an isoindoline ligand.

Preparation of olefin-acrylic copolymers with late transition metal catalysts

A process for making ethylene copolymers is disclosed. Ethylene copolymerizes with an &#x3b1;-olefin in the presence of a catalyst system comprising an activator and a silica-supported, bridged indenoindolyl metal complex having 'open architecture.' The supported complex incorporates comonomers with exceptional efficiency, and the process gives ethylene copolymers having high molecular weights (Mw&#x3e;100K) and very low densities (&#x3c;0.910 g/cm). Open architecture catalysts that include bridging through the indolyl nitrogen of the indenoindolyl framework are also described. Additionally, supported and unsupported indeno[1,2-b]indolyl catalysts provide exceptional activities in the preparation of elastomeric polypropylene and ethylene copolymers.

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West Chester, OH, United States of America

Mark P Mack