Abstract: Disclosed is a multimodal, high density, homopolyethylene barrier resin. The resin is preferably made by a multistage process. The process comprises a first stage in which ethylene is homopolymerized in the presence of a Ziegler-Natta catalyst, organoaluminum cocatalyst, alkoxysilane modifier, and hydrogen. The reaction mixture from the first stage is devolatilized to remove all or substantially all of the hydrogen. The polymerization continues in a second stage wherein ethylene is added to the devolatilized reaction mixture to produce the barrier resin. The barrier resin provides films with improved barrier properties.

Abstract: A polyolefin composition is disclosed. The composition comprises a single-site linear low density polyethylene (mLLDPE) and an elastoplastic polypropylene. The elastoplastic polypropylene is present in an amount sufficient to improve the processability and physical property of the mLLDPE. The composition preferably comprises from 70 wt % to 99 wt % of mLLDPE and from 1 wt % to 30 wt % of the elastoplastic polypropylene. The polyolefin composition of the invention exhibits improved bubble stability in the blown film extrusion compared to the mLLDPE and improved film properties such as tear strength and modulus compared to the traditional blend of mLLDPE and low density polyethylene.

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: 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: A process for extrusion coating metal foils and metallized films which utilizes a mixture of silanated and non-silanated ethylene polymers is provided.

Abstract: A method for producing a polypropylene-containing composition which includes (a) polymerizing a first quantity of propylene in a first reaction zone in the presence of a first polymerization catalyst to provide a first quantity of polypropylene having a weight-average molecular weight Mw,A; (b) polymerizing a second quantity of propylene optionally mixed with a minor amount of one or more olefins other than propylene in a second reaction zone in the presence of a second polymerization catalyst to provide a second quantity of polypropylene comprising a polypropylene homopolymer or random copolymer and having a weight-average molecular weight Mw,B; and (c) combining the first quantity of polypropylene with the second quantity of polypropylene to form a bimodal polypropylene; wherein the percent by weight of the first quantity of polypropylene in the bimodal polypropylene composition is equal to or greater than 65 percent, and the ratio Mw,B/Mw,A is at least about 2.

Abstract: A process for improving the melt characteristics of polyethylene resins is provided. The process involves contacting a polyethylene resin powder with a low level of free radical initiator at a temperature below the melting point of the resin.

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 improving the melt characteristics of polyethylene resins is provided. The process involves contacting a polyethylene resin powder with a low level of free radical initiator at a temperature below the melting point of the resin.

Abstract: Resins comprising a relatively high-density, low-molecular-weight polyethylene component and a relatively low-density, high-molecular-weight ethylene copolymer component and methods of making the resins are disclosed. The rheological polydispersity of the high-density component exceeds that of either the resin or the low-density component. The resins are valuable for making films, sheets, coatings, pipes, fibers, and molded articles having a favorable balance of good stiffness and excellent environmental stress crack resistance.

Abstract: Ethylene polymer composites, concentrates and a process utilized for their preparation are provided. The composites of the invention have increased melt strength compared to the base resin and other improved physical characteristics. The composites contain an organically modified clay and may also contain a compatibilizng agent, depending on the base resin used.

Abstract: Resins comprising a relatively high-density, low-molecular-weight polyethylene component and a relatively low-density, high-molecular-weight ethylene copolymer component and methods of making the resins are disclosed. The rheological polydispersity of the high-density component exceeds that of either the resin or the low-density component. The resins are valuable for making films, sheets, coatings, pipes, fibers, and molded articles having a favorable balance of good stiffness and excellent environmental stress crack resistance.

Abstract: Ethylene polymer composites, concentrates and a process utilized for their preparation are provided. The composites of the invention have increased melt strength compared to the base resin and other improved physical characteristics. The composites contain an organically modified clay and may also contain a compatibilizng agent, depending on the base resin used.

Abstract: A very low density polyethylene (VLDPE) film is disclosed. The film has a high average heat seal strength and physical strength. The VLDPE has a density within the range of about 0.880 to 0.914 g/cm3. The film has a seal initiation temperature lower than or equal to 95° C. and an average heat seal strength greater than or equal to 1.75 lb/in. The film has a machine-direction (MD) modulus greater than or equal to 12,000 psi. The film can be used as a monolayer film or as a layer of a multilayer film. It is suitable for heat sealable bags and many other applications.

Abstract: Ethylene polymer composites and concentrates utilized for their preparation are provided. The composites of the invention have increased melt strength compared to the base resin and other improved physical characteristics. The composites contain an organically modified clay and may also contain a compatibilizng agent, depending on the base resin used.

Abstract: A polyethylene having improved rheological properties is disclosed. The polyethylene has a melt index (MI2) from about 0.01 dg/min to about 50 dg/min and a melt strength (&eegr;) that satisfies MI2×&eegr;≧3.5. A process for making the polyethylene is also disclosed. The process uses an azaborolinyl-containing single-site catalyst in the presence of hydrogen, where the hydrogen consumption is controlled to be less than 30%.

Abstract: The present invention provides an ethylene copolymer resin that has unique melt elastic properties not observed in ethylene copolymers heretofore known. Specifically, the ethylene copolymer resin of the present invention when in pelletized form has a reduction in melt elasticity (ER) of 10% or more to a final value of 1.0 or less upon rheometric low shear modification or solution dissolution. Moreover, the resin of the present invention when in reactor-made form exhibits at least a partially reversible increase of 10% or more in ER when pelletizing the same. An ethylene polymerization catalyst, a process of preparing the ethylene copolymer resin and a high-impact film are also provided herein.

Abstract: Ethylene polymer composites and concentrates utilized for their preparation are provided. The composites of the invention have increased melt strength compared to the base resin and other improved physical characteristics. The composites contain an organically modified clay and may also contain a compatibilizng agent, depending on the base resin used.

Abstract: A polyethylene having improved rheological properties is disclosed. The polyethylene has a melt index (MI2) from about 0.01 dg/min to about 50 dg/min and a melt strength (&eegr;) that satisfies MI2×&eegr;≧3.5. A process for making the polyethylene is also disclosed. The process uses an azaborolinyl-containing single-site catalyst in the presence of hydrogen, where the hydrogen consumption is controlled to be less than 30%.