Abstract: A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.925 g/cc, a flow index (I21) no higher than about 15 g/10 min., a melt flow ratio (MFR) of at least about 65, and a dynamic elasticity at 0.1 rad./sec. of no higher than about 0.7 at a corresponding complex viscosity at 0.1 rad./sec. no higher than about 14×105 poises. The ethylene polymer is a bimodal of relatively high molecular weight (HMW) and low molecular weight (LMW) ethylene polymers.

Abstract: The invention is a polymerization catalyst system derived from tethered, heteroatom-bridged monocyclopentadienyl transition metal compound precursor from Group 4 of the Periodic Table of the Elements. The catalyst system comprises an activated, tethered pair of Group 4 transition metal compounds having a bidentate ancillary ligand system consisting of one cyclopentadienyl group bound to the transition metal and a Group 15 or Group 16 atom covalently bound to the transition metal and linked to the cyclopentadienyl group through a bridging group containing a Group 14-15 element. The ligand systems of each transition metal compound are tethered by at least one tethering group comprising a Group 13-16 element connected at both ends to either the Group 15 or Group 16 atom or the Groups 14-15 bridging group element. The catalyst system can be employed to polymerize olefins to produce a high molecular weight polymer.

Abstract: An oriented multilayer film is provided, the film including in at least one outer layer an ethylene copolymer having a density of 0.900-0.935 g/cm3 and a CDBI of 50-95% the outer layer is in contact with a polypropylene core layer, and the film is made by coextrusion of the ethylene copolymer and the polypropylene layer and subsequent orientation. The coextruded layers can be uniaxially oriented or biaxially oriented without difficulties caused by presence of low molecular weight amorphous polymer fractions inherently present in traditional Ziegler-Natta linear low density polyethylene. The optical properties of oriented polypropylene films can be retained, while the sealing temperature is lowered and the heat seal strength and the hot tack performance properties are improved.

Abstract: A process is provided for producing an essentially linear copolymer of ethylene and a minor amount of a 1-olefin containing more than 2 carbon atoms comprising contacting said ethylene and 1-olefin with a Ziegler catalyst in a polymerization reaction zone at elevated temperature and pressure, contacting the polymerization reaction mixture containing polymer and unreacted monomers with a fresh supply of ethylene in a high pressure separation zone (HPS) operating at a lower pressure than the reaction zone such that the contents of the separation zone separates into a dense phase containing a major proportion of polymer, and a light phase containing a major proportion of unreacted monomers, and separately withdrawing the two phases from the separation zone.

Abstract: A catalyst composition for the polymerization of one or more 1-olefins (e.g., ethylene) comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. In another embodiment, the transition metal catalyst precursor is bimetallic and contains a non-metallocene transition metal catalyst component. When a bimetallic catalyst precursor is used, the resin product exhibits improved properties, and has a bimodal molecular weight distribution, long chain branching (LCB), and good bubble stability.

Abstract: Films, containers made of high density polyethylene, and articles made therefrom exhibit, for a given density, improved resistance to water vapor transmission. The high density polyethylenes are produced in a metallocene-catalyzed production process. Alternatively, for equivalent water vapor transmission rates (WVTR) an article formed in accordance with the invention will exhibit improved physical properties, such as dart drop impact, more balanced tear properties and improved machine direction (MD) tear properties. Additionally, these high density polyethylenes show a low level of extractables and an excellent organoleptic profile.

Abstract: A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkylaluminum compound, and methylalumoxane.

Abstract: A make-up catalyst of at least one metallic component of a bimetallic catalyst component is used in conjunction with a bimetallic catalyst to control the proportion of weight fractions in broad or bimodal molecular weight distribution olefin resin product. The bimetallic catalyst which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought.

Abstract: Elastomeric polymers including ethylene, alpha-olefin and vinyl norbornene are shown to have improved extrusion characteristics, improved electrical properties, improved cure characteristics compared to ethylene, alpha-olefin, non-conjugated diene elastomeric polymers containing non-conjugated dienes other than vinyl norbornene. The elastomeric polymers containing vinyl norbornene generally have a branching index below 0.5. Such elastomeric polymers are combined with up to 30 parts of metallocene catalyzed ethylene, alpha-olefin copolymers to improve physical properties.

Abstract: This invention relates to a method of making polymer compositions, e.g. EPDM compositions, in a multistage reactor with monomers chosen from ethylene, C3-C8 alpha olefins, and a non conjugated diene. In particular, the invention relates to a process for improving diene conversion during the manufacture of the aforementioned polymer compositions by use of a multistage reactor and a metallocene catalyst system.

Abstract: This invention relates to a method of making polymer blends using series reactors and a metallocene catalyst. Monomers used by the invention are ethylene, a higher alpha-olefin (propylene most preferred), and optionally, a non-conjugated diene (ethylidene norbornene, i.e., ENB, most preferred). More specifically, this invention relates to making blends of EP (ethylene-propylene) copolymers in which the blend components differ in any of the following characteristics: 1) composition 2) molecular weight, and 3) crystallinity. We use the terminology EP copolymer to also include terpolymers that contain varying amounts of non-conjugated diene. Such terpolymers are commonly known as EPDM.

Abstract: The invention relates to a process for melt extruding a film layer of a thermoplastic olefin which comprises extruding the film having physical characteristics under process conditions selected by reference to the Draw ratio Dr and the Aspect ratio A such that draw resonance is avoided in which in addition the process conditions are defined by reference to the Deborah number such that the molten polymer is extruded at a Draw ratio of at least 30 in a high elasticity region at a &lgr;c value of characteristic time as defined herein of from 0.001 to 0.6 s, a Deborah number as defined herein in excess of 0.005 and an A value as defined herein lower than 0.8. Narrower ranges of these parameters may be defined for application of the invention to different polymer types.

Abstract: The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes comprising highly substituted noncoordinating anions that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers having significant amount of incorporated comonomer can be prepared with high molecular weights. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140° C. to 225° C.

Abstract: Extruded shapes, profiles and parts in general based on an ethylene, alpha-olefin elastomeric polymer are manufactured utilizing a tailored approach to polymerization, leading to a polymer that delivers all of the benefits of metallocene based polymers, but without the drawbacks. Additionally, the ethylene, alpha-olefin elastomeric polymer has a broader molecular weight distribution than generally available from metallocene catalyzed elastomeric polymers.

Abstract: The invention relates to electric power cables, transmission lines or coaxial cables having at least one polymeric component. This polymeric component generally is a conducting, semiconducting, protective or insulating component. The electrical cables of this invention have improved resistance to water treeing and other improved properties. The polymer generally comprises ethylene polymerized with at least one C3 to C20 alpha-olefin and optionally at least one C3 to C20 polyene. The polymer utilized has a density in the range of about 0.86 g/cm3 to about 0.96 g/cm3, a melt index in the range of about 0.2 dg/min. to about 100 dg/min., a molecular weight distribution in the range of about 1.5 to about 30, and a composition distribution breadth index greater than about 45 percent.

Abstract: A polymer of ethylene and at least one alpha olefin having at least 5, carbon atoms obtainable by a continuous gas phase polymerization using supported catalyst of an activated molecularly discrete catalyst such as a metallocene in the substantial absence of an aluminum alkyl based scavenger which polymer has a Melt Index (MI) as herein defined of from 0.1 to 15; a Compositional Distribution Breadth Index (CDBI) as defined herein of at least 70%, a density of from 0.910 to 0.930 g/ml; a Haze value as herein defined of less than 20%; a Melt Index ratio (MIR) as herein defined of from 35 to 80; an averaged Modulus (M) as herein defined of from 20 000 to 60 000 psi (pounds per square inch) and a relation between M and the Dart Impact Strength in g/mil (DIS) complying with the formula: DIS≧0.8×[100+e(11.71−0.000268×M+2.183×10−9×M2)].

Abstract: The invention relates to processes for producing polyolefins at pressures substantially below conventional high pressure conditions in two-phase conditions below the cloud point. The invention can involve a continuous system with optional recycle.

Abstract: This invention relates to thermoplastic olefin compositions of a low modulus which are suitable for fabrication into flexible skins and liners for applications which heretofore have been serviced by skins and liners produced essentially only from plasticized polyvinyl chloride resin compositions. TPO compositions of this invention comprise an impact modified polypropylene resin and a “plastomer” resin intimately blended in proportions with respect of one to another to provide a blend composition having a 1% secant modulus of less than 40,000 psi, and preferably less than 30,000 psi. Optionally, and preferably, the blend also comprises as a discrete component apart from the impact modified polypropylene an olefin copolymer elastomer or a cross-linked elastomer concentrate. Optionally the blend may contain other polyolefin components to alter its stiffness in desirable ways.

Abstract: Disclosed are hot melt adhesives comprising ethylene/alpha-olefin copolymers prepared with either supported or unsupported metallocene-alumoxane catalysts for applications in hot melt adhesives used in automotive product assembly, packaging and food packaging. These ethylene copolymers have weight average molecular weight ranging from about 20,000 to about 100,000 and comonomer weight percent ranging from about 6 to about 30. The hot melt adhesive composition includes the ethylene copolymer and a compatible tackifier at a ratio of tackifier to copolymer of from 70:30 to 30:70 and may also include up to 30 weight percent of a paraffinic and microcrystalline wax of the copolymer and tackifier.

Abstract: A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of said first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to t