- New catalyst system for producing polyethylene copolymers in a high temperature solution polymerization process
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Catalyst system for producing ethylene copolymers in a high temperature solution process, the catalyst system comprising (i) a metallocene complex of formula (I) wherein M is Hf or Zr X is a sigma ligand L is a bridge of the formula -SiR72
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- Asymmetric ansa-zirconocenes containing a 2-methyl-4-aryltetrahydroindacene fragment: Synthesis, structure, and catalytic activity in propylene polymerization and copolymerization
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A set of asymmetric bis-indenyl zirconium SiMe2-bridged ansa-complexes, containing 2-isopropyl-4-arylindenyl and 2-methyl-4- aryltetrahydroindacenyl fragments, have been synthesized. These complexes demonstrate better catalytic activity, stereoselectivty, and polymer molecular weight capability in propylene homo-and copolymerization in comparison to analogues without a tetrahydroindacenyl fragment.
- Nifant'ev, Ilya E.,Ivchenko, Pavel V.,Bagrov, Vladimir V.,Okumura, Yoshikuni,Elder, Michael,Churakov, Andrei V.
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experimental part
p. 5744 - 5752
(2012/01/14)
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- ORGANOMETALLIC TRANSITION METAL COMPOUND, BISCYCLOPENTADIENYL LIGAND SYSTEM, CATALYST SYSTEM AND PREPARATION OF POLYOLEFINS
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The present invention relates to organometallic transition metal compounds of the formula (I) where Mis an element of group 3, 4, 5 or 6 of the Periodic Table of the Elements or the lanthanides, the radicals X are identical or different and are each a
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Page/Page column 39
(2010/02/12)
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- GROUP 4 METAL COMPLEXES CONTAINING 4-ARYL-SUBSTITUTED, TRICYCLIC INDENYL DERIVATIVES
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Group 4 metal constrained geometry complexes comprising tricyclic 4-aryl-substituted indenyl ligands, especially 1,5,6,7-tetrahydro-4-aryl-s-indacen-1-yl ligands, catalytic derivatives thereof, processes for preparing the same and their use as components
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Page/Page column 12
(2010/02/06)
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- Control of stereoerror formation with high-activity "dual-side" zirconocene catalysts: A novel strategy to design the properties of thermoplastic elastic polypropenes
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The new C1-symmetric complexes rac-[1-(9-η5-fluorenyl)-2-(2-methylbenz[e]-1-η 5-indenyl)ethane]-zirconium dichloride (14a), rac-[1-(9-η5-fluorenyl)-2-(4,5-cyclohexa-2-methyl-1-η 5-indenyl)ethane]zirconium dichloride (14b), and rac-[1-(9-η5-fluorenyl)-2-(5,6-cyclopenta-2-methyl-l-η 5-indenyl)ethane]zirconium dichloride (15) were prepared in up to 93% yield. These compounds, activated with methyl aluminoxane, exhibit high active propene polymerization rates which remain constant over hours, even at elevated polymerization temperatures of 50 and 70°C. The two different coordination sites of these "dual-side" catalysts lead to isotactic polypropenes with variable amounts of stereoerrors, depending on the monomer concentration. The 2-methyl substituent of the indenyl ligands results, at the same time, in significantly increased molecular weights of the polymer products (up to 2.3 × 105 g mol-1), the bulk properties of which can be adjusted from flexible, semicrystalline thermoplastic to excellent thermoplastic elastic.
- Dietrich, Ulf,Hackmann, Martijn,Rieger, Bernhard,Klinga, Martti,Leskelae, Markku
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p. 4348 - 4355
(2007/10/03)
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