Abstract: A novel UHMW polyethylene material, which is displaying excellent abrasion resistance amongst other properties, is devised.

Abstract: New ethylene polymers having broad molecular weight distribution and long-chain branching, above all at high molecular weight fractions; the polymers have strain hardening equal or higher than 1.4 (at constant elongational rate of 0.5 s?1, at 150° C.), branching index g? equal or lower than 0.9 (at Mw of 2·106 g/mol). The polymers are prepared by using a mixed catalyst system comprising a polymerization catalyst based on a late transition metal component having a tridentate ligand, and a Ziegler polymerization catalyst annealed at a temperature higher than 100° C., for a time of at least 10 minutes.

Abstract: Process for the preparation of an ethylene copolymer composition having a polydispersity index Mw/Mn of from 3 to 100, comprising a) feeding ethylene to at least one polymerization reactor; b) performing in the at least one polymerization reactor an oligomerization of ethylene in the presence of an oligomerization catalyst component (C) to produce comonomer; c) performing simultaneously in the at least one polymerization reactor polymerization reactions in the presence of catalyst components (A) and (B) producing, respectively, a first and a second polyethylene fraction, wherein the weight average molecular weight Mw of the first polyethylene fraction produced by catalyst component (A) is less than the Mw of the second polyethylene fraction produced by catalyst component (B) and the comonomer incorporation ability of catalyst component (B) is higher than the comonomer incorporation ability of catalyst component (A); and d) withdrawing the ethylene copolymer composition from the polymerization reactor.

Abstract: Process for the preparation of an ethylene copolymer composition having a polydispersity index Mw/Mn of from 3 to 100, comprising a) feeding ethylene to at least one polymerization reactor; b) performing in the at least one polymerization reactor an oligomerization of ethylene in the presence of an oligomerization catalyst component (C) to produce comonomer; c) performing simultaneously in the at least one polymerization reactor polymerization reactions in the presence of catalyst components (A) and (B) producing, respectively, a first and a second polyethylene fraction, wherein the weight average molecular weight Mw of the first polyethylene fraction produced by catalyst component (A) is less than the Mw of the second polyethylene fraction produced by catalyst component (B) and the comonomer incorporation ability of catalyst component (B) is higher than the comonomer incorporation ability of catalyst component (A); and d) withdrawing the ethylene copolymer composition from the polymerization reactor.

Abstract: A novel UHMW polyethylene material, which is displaying excellent abrasion resistance amongst other properties, is devised.

Abstract: Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-(2-aryloxy)quinoline or 2-(2-aryloxy)dihydroquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.

Abstract: A method of preparing supported catalysts useful for olefin polymerization is described. The catalysts comprise a Group 4 metal complex that incorporates a tridentate dianionic ligand. An activator mixture is first made from a boron compound having Lewis acidity and an excess of an alumoxane. The activator mixture is then combined with a support and the Group 4 metal complex to give a supported catalyst. The method provides an active, supported catalyst capable of making high-molecular-weight polyolefins.

Abstract: Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise a transition metal complex, an optional activator, and an optional support. The complex is the reaction product of a Group 3-6 transition metal source, an optional alkylating agent, and a ligand precursor comprising a 2-imino-8-anilinoquinoline or a 2-aminoalkyl-8-anilinoquinoline. The catalysts, which are easy to synthesize by in-situ metallation of the ligand precursor, offer polyolefin manufacturers good activity and the ability to make high-molecular-weight ethylene copolymers that have little or no long-chain branching.

Abstract: New ethylene polymers having broad molecular weight distribution and long-chain branching, above all at high molecular weight fractions; the polymers have strain hardening equal or higher than 1.4 (at constant elongational rate of 0.5 s?1, at 150° C.), branching index g? equal or lower than 0.9 (at Mw of 2·106 g/mol). The polymers are prepared by using a mixed catalyst system comprising a polymerization catalyst based on a late transition metal component having a tridentate ligand, and a Ziegler polymerization catalyst annealed at a temperature higher than 100° C., for a time of at least 10 minutes.

Abstract: The invention pertains to a method for the preparation of ultra high molecular mass polyethylene by polymerization in suspension or in gas phase in the presence of a chromium catalyst sitting on an alumosilicate support material. The chromium catalyst has been subjected to a fluorinating treatment and the polymerization is performed under low temperature conditions within a temperature range of from 50 to 100° C. The invention pertains also to ultra high molecular mass polyethylene prepared by that method and having a density in the range of from 0.930 to 0.950 g/cm3.

Abstract: A method for preparing a supported catalyst suitable for use in slurry and gas-phase olefin polymerizations is disclosed. An alumoxane-treated silica is combined with a monocyclopentadienyl Group 6 metal complex that comprises a chelating Cp moiety to give the supported catalyst. The method is simple to practice and provides catalysts having high activity. Polyolefins made using the catalysts have high molecular weight that is readily controlled by adding hydrogen.

Abstract: A method of preparing supported catalysts useful for olefin polymerization is described. The catalysts comprise a Group 4 metal complex that incorporates a tridentate dianionic ligand. An activator mixture is first made from a boron compound having Lewis acidity and an excess of an alumoxane. The activator mixture is then combined with a support and the Group 4 metal complex to give a supported catalyst. The method provides an active, supported catalyst capable of making high-molecular-weight polyolefins.

Abstract: Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-(2-aryloxy)quinoline or 2-(2-aryloxy)dihydroquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.

Abstract: Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-aryl-8-anilinoquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.