Abstract: A thick film and process to prepare polyethylene useful for the film are disclosed. Ethylene is polymerized in two reaction zones with a C6-C10 ?-olefin in the presence of a catalyst system comprising an activator, a supported bridged zirconium complex, and a supported non-bridged zirconium complex. The process yields medium density to linear low density polyethylene having a melt index from 0.20 to 1.0 dg/min. Thick films from the polyethylene have a superior combination of high impact strength and high modulus.

Abstract: A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of an ?-olefin and a catalyst comprising an activator and a supported bridged indeno[1,2-b]indolyl zirconium complex. The process produces polyethylene characterized by good incorporation of the ?-olefin and low long-chain branching. The process is capable of forming high-molecular-weight polyethylene and has good hydrogen sensitivity.

Abstract: A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in a first reactor in the presence of hydrogen and a catalyst comprising an activator and a supported dimethylsilyl-bridged indeno[1,2-b]indolyl zirconium complex to produce an ethylene homopolymer, removing some of the unreacted hydrogen, and reacting the homopolymer slurry in a second reactor with ethylene and a C3-C10 ?-olefin to produce polyethylene. The polyethylene has weight-average molecular weight greater than 150,000, broad molecular weight distribution, low long-chain branching, and it provides pipes or molded articles with good environmental stress crack resistance.

Abstract: A process for making polyethylene having an uncommon but valuable balance of broad molecular weight distribution and a low level of long-chain branching is disclosed. The process comprises polymerizing ethylene in a single reactor in the presence of an ?-olefin and a catalyst comprising an activator and a supported dialkylsilyl-bridged bis(indeno[1,2-b]indolyl)zirconium complex. The polyethylene, which has an Mw/Mn greater than 10 and a viscosity enhancement factor (VEF) of less than 2.5, is valuable for making blown films.

Abstract: A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of an ?-olefin and a catalyst comprising an activator and a supported bridged indeno[1,2-b]indolyl zirconium complex. The process produces polyethylene characterized by good incorporation of the ?-olefin and moderate long-chain branching. The process is capable of forming high molecular weight polyethylene and has good catalyst activity.

Abstract: A process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in a slurry reaction in the presence of a catalyst system which comprises an activator and an indenoindolyl transition metal complex on a support material. The catalyst system is slurried with an inert solvent prior to addition to the reactor. The process provides polyethylene with good bulk density.

Abstract: A process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of a catalyst system which comprises a bridged indenoindolyl transition metal complex on a support material, an alkylalumoxane, a titanium tetralkoxide, and a branched alkyl aluminum compound. The process provides polyethylenes with low density from ethylene alone.

Abstract: A process to remove metal contaminants from a hydrocarbon solution of polyethylene is disclosed. The process comprises adding a primary alcohol and a ?-diketone to a solution of polyethylene at a temperature within the range of 120° C. to 300° C. and contacting the solution with basic alumina. The process removes metal contaminants and minimizes degradation and condensation products, which can have a detrimental effect on polyethylene properties. The process provides polyethylene with low metal residues and good properties.

Abstract: A lubricating oil suitable for use in ?-olefin compressors and a high-pressure ethylene polymerization process is disclosed. The oil comprises a base fluid and a hindered C6-C30 alkyl 4-hydroxybenzoate. The hindered C6-C30 alkyl 4-hydroxybenzoate stabilizes the lubricating oil and does not interfere with the high-pressure ?-olefin polymerization.

Abstract: A thick film produced from a polyolefin blend is disclosed. The film is prepared from a blend having a density from 0.935 to 0.955 g/cm3 and comprising LLDPE and greater than 50% by weight HDPE having a density greater than 0.955 g/cm3. The film has a modulus in the machine direction from about 75,000 to about 130,000 psi and improved machine direction tear strength.

Abstract: A process for polymerizing ethylene is disclosed. The polymerization is performed in the presence of a Ziegler-Natta catalyst system in two slurry reaction zones. Most of the polyethylene (70-95 wt. %) is produced in one of the zones, while a smaller fraction is produced in the other zone. The ratio of the weight average molecular weight of the smaller fraction to that of the larger fraction is greater than 8:1. The resulting polyethylene blend, which should have both high melt strength and high extrudate swell, will be useful for blow-molding applications.

Abstract: An ethylene polymerization process is disclosed. Ethylene is polymerized in two slurry reaction zones with a C6-C10 alpha-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.

Abstract: A method for preparing an olefin polymerization catalyst is disclosed. An inorganic oxide is contacted with plasma and a transition metal compound is supported on the contacted inorganic oxide. The method is fast, convenient, and avoids many of the problems associated with known methods of supporting catalysts.

Abstract: 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.

Abstract: A catalyst system useful for polymerizing olefins is disclosed. The catalyst system comprises a cocatalyst and a supported transition metal prepared from a halogen-containing Group 4–6 transition metal compound and an organoaluminum-siloxane containing mixture. The latter mixture, which is prepared from an organoaluminum compound and an organomagnesium-siloxane reaction product, incorporates a chelating ligand. The invention includes a method for making the catalyst system and a process for polymerizing olefins using the catalyst system. The process is convenient and avoids expensive catalyst components used in known olefin polymerization processes.

Abstract: A process for polymerizing an alpha-olefin is disclosed. The polymerization is performed in the presence of a catalyst system comprising a three-membered titanacycle. A wide variety of titanacycles can be readily prepared, making this a versatile and inexpensive olefin polymerization process.

Abstract: A modified Ziegler-Natta catalyst system comprising a titanium or vanadium compound, a magnesium compound, a carbene donor, and an aluminum compound is disclosed. The invention includes a process which comprises polymerizing an alpha-olefin in the presence of the carbene-modified Ziegler-Natta catalyst system. The carbene donor may be used as either an internal or external donor. The use of carbene donors in Ziegler-Natta catalyzed olefin polymerizations should improve catalyst activity and/or stereospecificity.

Abstract: A process for purifying grafted polyolefins by extraction is disclosed. The purified grafted polyolefins have improved color and adhesion properties. The extraction is performed with an azeotropic solvent that is strong enough to extract impurities but does not cause sticking of the grafted polyolefin. The azeotropic solvent can be easily recycled.

Abstract: 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.

Abstract: A process for making polyolefins is disclosed. The process comprises polymerizing an olefin in the presence of an activator, an organometallic complex, and an aluminum phosphate support. The complex comprises a Group 3 to 10 transition metal and an indenoindolyl ligand that is bonded to the transition metal. The use of the aluminum phosphate support in combination with the indenoindolyl complex provides an unexpected boost in catalyst activity when compared with other common supports. When a combination of olefins is used, good comonomer incorporation is obtained.