Exxonmobil Chemical Patents Inc.

Exxon Chemical Patents, Inc.

Univation Technologies, LLC

George Alan Vaughan

Donna Jean Crowther

Phillip Thomas Matsunaga

Kevin Richard Squire

David Edward Gindelberger

Ching-Tai Lue

Jo Ann Marie Canich

Moses Olukayode Jejelowo

Joseph C Floyd

Ching Tai Lue

Michael E Muhle

Patrick Brant

John Francis Szul

Sun-Chueh Kao

Anthony Nicholas Speca

James McLeod Farley

Jo Ann Canich

John F Walzer, Jr

Timothy Daniel Shaffer

Natalie Ann Merrill

Matthew Gary McKee

Charles Stanley Speed

Richard Allen Fisher

Howard William Turner

Bernard Jean Folie

Terry John Burkhardt

Laughlin G McCullough

Jeffrey Lawrence Brinen

Michael D Awe

Rinaldo Soria Schiffino

Edward F Smith

Ronald N Cooke

Rolf Bodo Temme

James R Sollen

Sateesh K Rajput

Ahmed H Ali

Mike Awe

A process for reducing the loss of catalyst activity of a Ziegler-Natta catalyst is provided. The process includes preparing a Ziegler-Natta (ZN) catalyst by contacting the ZN catalyst with at least one aluminum alkyl compound to produce a reduced ZN catalyst and storing and/or transporting the reduced ZN catalyst for at least 20 days at a temperature of 25&#xb0; C. or less. The reduced ZN catalyst may be used for polymerizing polyolefin polymers.

Processes for reducing the loss of catalyst activity of a Ziegler-Natta catalyst

The invention comprises an olefin polymerization process comprising contacting ethylene alone or with one or more olefinically unsaturated comonomers with a Group 3-6 metallocene catalyst compound comprising one &#x3c0;-bonded ring having a Cor greater hydrocarbyl, hydrocarbylsilyl or hydrocarbylgermyl substituent said substituent bonded to the ring through a primary carbon atom; and, where the compound contains two &#x3c0;-bonded rings, the total number of substituents on the rings is equal to a number from 3 to 10, said rings being asymmetrically substituted where the number of substituents is 3 or 4. The invention process is particularly suitable for preparing ethylene copolymers having an MIR less than about 35, while retaining narrow CD even at high comonomer incorporation rates, and with certain embodiments providing ethylene copolymers having improved melt strength with the low MIR.

Olefin polymerization process with alkyl-substituted metallocenes

A 3+ metal complex for coordination polymerization of olefins is disclosed. The precursor metal complex is stabilized by a anionic multidentate ligand and at least two monoanionic ligands. The multidentate ligand and the transition metal form a metallocycle having at least five primary atoms, counting any &#x3c0;-bound cyclopentadienyl group in the metallocycle as two primary atoms. Olefin polymerization is exemplified.

Cationic catalyst system

The present invention provides polymerization catalyst compounds, catalyst systems including these catalyst compounds, and to their use in the polymerization of ethylene and at least one comonomer. In particular, the invention provides a catalyst system comprising a poor comonomer incorporating catalyst compound and a good comonomer incorporating catalyst compound. Preferably, the low comonomer incorporating catalyst compound is a metallocene containing at least one substituted or unsubstituted fused ring cyclopentadienyl based ligand which is substantially directed to the front of the molecule, contains a long bridging group, or which contains a methyl substitution pattern which correlates to poor comonomer incorporation. The invention also provides methods of selecting the poor comonomer incorporating metallocene to pair with the good comonomer incorporating metallocene to produce polymers that are easy to process into a variety of articles, especially polyethylene based film, having enhanced properties.

Mixed metallocene catalyst systems containing a poor comonomer incorporator and a good comonomer incorporator

The invention encompasses late transition metal catalyst systems immobilized on solid supports and their use in heterogenous polymerization processes, particularly in gas phase polymerization of olefin monomers. Preferred embodiments include a late transition metal catalyst system comprising a Group 9, 10, or 11 metal complex stabilized by a bidentate ligand structure immobilized on a solid porous metal or metalloid oxide particle support, particularly those comprising silica. The gas phase polymerization process for olefin monomers comprises contacting one or more olefins with these catalyst systems under gas phase polymerization conditions.

Supported late transition metal catalyst systems

The present invention provides polymerization catalyst compounds, catalyst systems including these catalyst compounds, and to their use in the polymerization of ethylene and at least one comonomer. In particular, the invention relates to identifying the comonomer incorporation behavior of metallocene polymerization catalyst compounds. More particularly, the invention relates to identifying metallocene catalyst compounds which incorporate comonomer poorly. Preferably, such metallocene catalyst compounds contain at least one substituted or unsubstituted fused ring cyclopentadienyl based ligand. The invention also relates to the use of these low comonomer incorporating metallocene catalyst compounds in catalyst systems to produce polymers that are easy to process into a variety of articles, especially polyethylene based film, having enhanced properties.

Low comonomer incorporating metallocene catalyst compounds

The invention comprises an olefin polymerization process comprising contacting ethylene alone or with one or more olefinically unsaturated comonomers with a Group 3-6 metallocene catalyst compound comprising one &pgr;-bonded ring having a C or greater hydrocarbyl, hydrocarbylsilyl or hydrocarbylgermyl substituent said substituent bonded to the ring through a primary carbon atom; and, where the compound contains two &pgr;-bonded rings, the total number of substituents on the rings is equal to a number from 3 to 10, said rings being asymmetrically substituted where the number of substituents is 3 or 4. The invention process is particularly suitable for preparing ethylene copolymers having an MIR less than about 35, while retaining narrow CD even at high comonomer incorporation rates, and with certain embodiments providing ethylene copolymers having improved melt strength with the low MIR.

The invention encompasses a mixed transition metal olefin polymerization catalyst system suitable for the polymerization of olefin monomers comprising one late transition metal catalyst system and at least one different catalyst system selected from the group consisting of late transition metal catalyst systems, transition metal metallocene catalyst systems or Ziegler-Natta catalyst systems. Preferred embodiments include at least one late transition metal catalyst system comprising a Group 9, 10, or 11 metal complex stabilized by a bidentate ligand structure and at least one transition metal metallocene catalyst system comprising a Group 4 metal complex stabilized by at least one ancillary cyclopentadienyl ligand. The polymerization process for olefin monomers comprises contacting one or more olefins with these catalyst systems under polymerization conditions.

Mixed transition metal catalyst systems for olefin polymerization

Easy processing linear low density polyethylene

Growing community of inventors

Houston, TX, United States of America

George Alan Vaughan