Abstract: A catalyst system useful for polymerizing olefins is disclosed. The catalyst system includes an organometallic complex that incorporates a Group 3 to 10 transition metal and an anionic, polycyclic, convex ligand. Molecular modeling results indicate that the complexes, when combined with an activator, should actively polymerize olefins. The convex ligand uniquely stabilizes the active site while simultaneously minimizing steric interference. Calculations predict that complexes based on ligands with a high curvature index will have favorable reactivities with olefin monomers compared with similar complexes that incorporate Cp-like ligands.

Abstract: A catalyst system useful for polymerizing olefins is disclosed. The catalyst system comprises an activator and an organometallic complex that incorporates a Group 3 to 10 transition metal and at least one chelating, dianionic triquinane ligand. The cis,syn,cis-triquinane framework is generated in three high-yield steps from inexpensive starting materials, and with heat and light as the only reagents. By modifying substituents on the triquinane ligand, polyolefin makers can control catalyst activity, comonomer incorporation, and polymer properties.

Abstract: 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.

Abstract: A process for polymerizing propylene is disclosed. The propylene is polymerized with a catalyst system which comprises an activator and a [1,2-b]indenoindolyl Group 4-6 transition metal complex having open architecture. The process has high catalyst activity and gives high molecular weight elastomeric polypropylene.

Abstract: A propylene polymerization process is disclosed. The process uses a fluorenyl-indenoindolyl catalyst precursor in the presence of an activator to obtain high molecular weight polypropylene with low degrees of isotacticity and syndiotacticity. In particular, the polypropylene has tacticity such that mmmm is 0-20% and rrrr is 0-60%.

Abstract: 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.

Abstract: 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° 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.

Abstract: A clay-filled polyolefin composition and process for making it are disclosed. The process involves treatment of a non-acid-treated smectite clay with a Ziegler-Natta catalyst in the presence of a hydrocarbon and subsequent polymerization of an olefin in the presence of the treated clay and an organoaluminum cocatalyst. Results indicate that filled compositions produced by this process contain exfoliated clay.

Abstract: A process for the polymerization of olefins is disclosed. A boraaryl catalyst precursor and an activator are used in the presence of a silane modifier. A low level of silane modifier enhances the activity of the catalyst.

Abstract: A process for polymerizing an olefin is disclosed. The olefin is polymerized with a catalyst precursor in the presence of an activator and an organosilane modifier. Use of the organosilane increases polyolefin molecular weight. The process is easy to practice and affords polyolefins with conventional polymerization methods such as slurry polymerizations or gas-phase polymerizations.

Abstract: A process for polymerizing propylene is disclosed. The process involves charging propylene and about 90 to 99% of an organoaluminum cocatalyst to a reactor and heating this mixture to at least about 50° C. This is followed by addition of a premix of 1 to 10% of the organoaluminum cocatalyst with a magnesium halide-supported Ziegler-Natta catalyst. The temperature of the reaction mixture is maintained to produce a propylene polymer. The process gives improved catalyst activity.

Abstract: A process for producing cyclopentane from by-product streams containing cyclopentene consists of distilling the cyclopentene from the feedstream and then hydrotreating the cyclopentene-containing fraction to cyclopentane. A second distillation step may then be employed to remove the hydrocarbons which are lighter than cyclopentane. The process has particular applicability in the treatment of feedstreams containing neo-hexane. The cyclopentene is easily separated from the neo-hexane in a conventional fractionator.

Abstract: An olefin polymerization catalyst system and method of making it are disclosed. The catalyst system comprises an activator and an organometallic complex. The complex comprises a Group 3 to 10 transition or lanthanide metal, M, and at least one anionic 1,3-diboretanyl ligand that is bonded to M. Molecular modeling results indicate that catalysts from organometallic complexes that incorporate anionic 1,3-diboretanyl ligands will rival the performance of traditional metallocenes.

Abstract: A single-site olefin polymerization catalyst and method of making it are disclosed. The catalyst comprises an activator and an organometallic complex. The complex comprises a Group 3 to 10 transition metal, M, and at least one anionic heterocyclobutenyl ligand that is bonded to M. Molecular modeling results indicate that single-site catalysts based on anionic heterocyclobutenyl ligands will have advantages compared with the performance of catalysts based on cyclopentadienyl and substituted cyclopentadienyl ligands.

Abstract: Single-site catalysts useful for polymerizing olefins are disclosed. The catalysts incorporate a Group 3 to 10 transition, lanthanide, or actinide metal and an anionic thiopyran dioxide ligand. Because a wide variety of thiopyran dioxides are easy to prepare from commercially available starting materials, the invention enables the preparation of a new family of single-site catalysts.

Abstract: 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.

Abstract: A process for making ethylene copolymers is disclosed. Ethylene copolymerizes with an &agr;-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>100K) and very low densities (<0.910 g/cm3). Open architecture catalysts that include bridging through the indolyl nitrogen of the indenoindolyl framework are also described.

Abstract: A catalyst system useful for polymerizing olefins is disclosed. The catalyst system comprises an activator and a complex that incorporates a Group 3 to 10 transition metal and at least one chelating dianionic bis(allyl) or bis(benzyl) ligand. The ligands are often easy to make, and they are readily incorporated into transition metal complexes. By modifying the structure of the dianionic ligand, polyolefin makers can control comonomer incorporation, catalyst activity, and polymer properties.

Abstract: A two-step, base-catalyzed process for making crosslinked polyvinylpyrrolidone (PVP-P) having a low swell volume is disclosed. A crosslinker is generated “in situ” in the first step by heating a basic aqueous mixture containing a relatively low concentration of N-vinylpyrrolidone under added inert gas pressure. In a second step, the reactor temperature is reduced to initiate polymerization. The process is a productive way to make PVP-P that is easy to isolate and purify. The polymer has a swell volume less than about 40 mL H2O/10 g polymer, which makes it valuable for beverage clarification.

Abstract: A single-site olefin polymerization catalyst and method of making it are disclosed. The catalyst comprises an activator and an organometallic complex. The complex comprises a Group 3 to 10 transition or lanthanide metal, M, and at least one chelating N-oxide ligand that is bonded to M. Molecular modeling results indicate that single-site catalysts based on certain chelating N-oxide ligands (e.g., 2-hydroxypyridine) will rival the performance of catalysts based on cyclopentadienyl and substituted cyclopentadienyl ligands.