Equistar Chemicals, LP

Jia-Chu X Liu

Shao-Hua Guo

Mark P Mack

Shaotian Wang

Clifford C Lee

Bradley P Etherton

Michael W Lynch

Leonard V Cribbs

Linda N Winslow

Jonathan L Schuchardt

Karen E Meyer

A process for polymerizing unsaturated monomers is disclosed. The process comprises polymerizing, in the presence of a late transition metal catalyst (LTMC), a variety of unsaturated monomers which are traditionally, some of which are exclusively, made by free radical polymerizations. The LTMC polymerization provides the polymer with improved properties such as no free radical residue and narrow molecular weight distribution.

LTMC polymerization of unsaturated monomers

An olefin polymerization process is disclosed. The polymerization is performed in the presence of a clay, an activator, and a transition metal complex that has at least one pyridine moiety-containing ligand. The presence of clay increases the catalyst activity. The process is suitable for making ultra-high molecular weight polyethylenes (UHMWPE). The UHMWPE produced has increased bulk density.

Olefin polymerization with pyridine moiety-containing single-site catalysts

A method for making single-site catalysts useful for olefin polymerization is disclosed. A nitrogen-functional heterocycle is first deprotonated with an alkyllithium compound, followed by reaction of this anionic ligand precursor with about 0.5 equivalents of a Group 4 transition metal tetrahalide in a hydrocarbon solvent at a temperature greater than about 10&#xb0; C. to give an organometallic complex-containing mixture. When combined with exceptionally low levels of an activator (e.g., methyl alumoxane), the mixture actively polymerizes olefins to give polymers with a favorable balance of physical properties, including low density and narrow molecular weight distribution.

Single-site catalysts for olefin polymerization

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

Olefin polymerization with pyridine moiety-containing singe-site catalysts

A catalyst system useful for polymerizing olefins is disclosed. It comprises an activator and an organometallic complex. The complex includes a Group 3-10 transition or lanthanide metal and a 1,3-bis(arylimino)isoindoline or 1,3-bis(heteroarylimino)isoindoline ligand. Activities of the Group 8-10 catalyst systems rival or exceed those of late transition metal bis(imines). The resulting polyolefins typically have high molecular weights, broad molecular weight distributions, and a high degree of crystallinity, which makes them valuable for film applications.

Transition metal catalysts for olefin polymerization

A method for making supported single-site catalysts useful for olefin polymerization is disclosed. An organometallic complex that contains a nitrogen-functional heterocyclic ligand is first prepared and reacted with an alumoxane. This product is then combined, preferably with high-intensity mixing, with a slurry of inorganic support, followed by solvent removal to give a supported catalyst. By introducing the alumoxane at the right time during preparation, and by judicious selection and chemical treatment of the inorganic support, one can make catalysts with high activity and good aging properties. The supported catalysts give olefin polymers with a favorable balance of physical properties, including low density, narrow molecular weight distribution, good melt-flow properties, and high bulk density.

Supported single-site catalysts useful for olefin polymerization

A method for making single-site catalysts useful for olefin polymerization is disclosed. A nitrogen-functional heterocycle is first deprotonated with an alkyllithium compound, followed by reaction of this anionic ligand precursor with about 0.5 equivalents of a Group 4 transition metal tetrahalide in a hydrocarbon solvent at a temperature greater than about 10&deg; C. to give an organometallic complex-containing mixture. When combined with exceptionally low levels of an activator (e.g., methyl alumoxane), the mixture actively polymerizes olefins to give polymers with a favorable balance of physical properties, including low density and narrow molecular weight distribution.

A process for making an ultra-high-molecular-weight polyethylene (UHMWPE) is disclosed. The process is performed with a supported quinolinoxy-containing single-site catalyst in the presence of a non-alumoxane activator, but in the absence of an &agr;-olefin, an aromatic solvent, and hydrogen. The process significantly increases the catalyst activity and the UHMWPE produced has improved tensile and impact properties.

Preparation of ultra-high-molecular-weight polyethylene

Methods for making Group VIII metal bis(imine) complexes are disclosed. Each method uses a single reactor that is equipped with an internal filter to facilitate preparation and purification of the complex under an inert atmosphere. The complexes, which are useful in catalyst systems for olefin polymerization, are prepared in either one or two reaction steps. Surprisingly, the single-reactor approach to preparation and purification enables the efficient preparation of exceptionally high (>90%) yields of desirable Group VIII metal bis(imine) complexes.

Method for making late transition metal catalysts for olefin polymerization

An ultra-high-molecular-weight polyethylene (UHMWPE) is disclosed. The UHMWPE has a weight average molecular weight (Mw) greater than about 3,000,000 and molecular weight distribution less than about 5. A process for making the UHMWPE is also disclosed. The process is performed with a heteroatomic ligand-containing single-site catalyst in the presence of a non-alumoxane activator, but in the absence of an &agr;-olefin, an aromatic solvent, and hydrogen.

A gas phase copolymerization of ethylene is disclosed. The process uses a supported single-site catalyst that contains a heteroatomic ligand and produces polyethylene that has a reduced density. Suitable heteroatomic ligands include boraaryl, azaborolinyl, pyridinyl, pyrrolyl, indolyl, carbazolyl and quinolinyl.

Ethylene polymerization process

An improved catalyst for polymerizing olefins is disclosed. The catalyst comprises a Group 4 transition metal, at least one quinolinoxy or pyridinoxy ligand, and at least one benzyl ligand. Particularly when used with an activator, the benzyl-containing catalysts have exceptional activities for polymerizing olefins.

Quinolinoxy and pyridinoxy single-site catalysts containing benzyl ligands

A supported olefin polymerization catalyst system and a method of making it are disclosed. The catalyst system comprises: (a) a support chemically treated with an organoaluminum, organosilicon, organomagnesium, or organoboron compound; (b) a single-site catalyst that contains a polymerization-stable, heteroatomic ligand; and (c) an activator. Chemical treatment is a key to making supported heterometallocenes that have high activity and long shelf-lives, and can effectively incorporate comonomers.

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Mason, OH, United States of America

Jia-Chu X Liu