Silicon-bridged transition metal compounds
Patent 5441920 Issued on August 15, 1995. Estimated Expiration Date: 
December 2, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 2, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesHafnium metallocene catalyst for the polymerization of olefins Patent #: 4794096 InventorAssigneeApplicationNo. 161828 filed on 12/02/1993US Classes:502/103, Component A metal is Group IA, IIA or IIIA and component B metal is Group IVB to VIIB or VIII (i.e., alkali metal, alkaline earth Metal, Be, Mg, Al, Ga, In or Tl and Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, iron Group or Platinum group) (e.g., Ziegler Catalyst, etc.)502/117, Component B metal is other than titanium or vanadium502/152, Organic compound including carbon-metal bond526/126, Material contains silicon atom526/127, Contains non-transition free metal, hydride thereof, or carbon to non-transition metal atom bond526/160, Transition metal bonded to carbon atom526/170, Transition metal bonded to carbon atom526/348.2, At least six carbon atoms526/348.4Six carbon atoms onlyExaminersPrimary: Pal, AsokAttorney, Agent or FirmForeign Patent References
International ClassesC07F 007/02C08F 004/42 C08F 004/64 AbstractSilicon-bridged transition metal compounds and their use as alpha-olefin polymerization catalysts are disclosed. The polymerization catalyst comprises a chiral silicon-bridged metallocene of the following structure: ##STR1## where M is a transition metal, X' and X" are the same or different hydride, halogen, hydrocarbyl or halohydrocarbyl groups having up to about 6 carbon atoms, A' and A" are each the same or different asymmetrical mononuclear or polynuclear hydrocarbyl or silahydrocarbyl moieties and S' is a bridge of 1-4 atoms selected from the group consisting of silanylene, silaalkylene, oxasilanylene, and oxasilaalkylene, and may include an alumoxane. Specifically, the transition metals are titanium, zirconium, and hafnium.Other References
Field of SearchComponent A metal is Group IA, IIA or IIIA and component B metal is Group IVB to VIIB or VIII (i.e., alkali metal, alkaline earth Metal, Be, Mg, Al, Ga, In or Tl and Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, iron Group or Platinum group) (e.g., Ziegler Catalyst, etc.)Component B metal is other than titanium or vanadium Organic compound including carbon-metal bond |
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