Narrow MWD alpha-olefin copolymers Patent #: 4540753
ApplicationNo. 767523 filed on 09/25/1991
US Classes:526/144, Non-metal material is organic halogen-containing compound526/169.2, Transition metal is vanadium526/281, Bridged monomer526/282, Contains an exterior ethylenic substituent bonded to a single carbon atom of the bridged ring system526/336Ethylenic groups are non-conjugated, e.g., divinylbenzene, etc.
ExaminersPrimary: Teskin, Fred
Attorney, Agent or Firm
Foreign Patent References
International ClassesC08F 002/04
AbstractThe present invention is directed toward novel copolymers of ethylene and at least one other alpha-olefin monomer which copolymers have an intermolecular compositional distribution (CD), such that at least about 25% by weight of the polymer differs from the mean ethylene content of the polymer by at least plus or minus 5 wt % ethylene and a relatively narrow molecular weight distribution (MWD) such that the weight average molecular weight (Mw) of the polymer divided by the number average molecular weight (Mn) by the polymer is not greater than about 5.0.The polymers of this invention, which are characterized by exceptional green strength and good processing properties, may be prepared using a catalyst system comprising:a) a vanadium compound with a valence of 3 or more;b) a triorgano aluminum compound; andc) a specific halogenated organic promoter used in catalytic amounts.The catalyst system allows for efficient polymerization of high quality polymer products and at generally higher polymerization temperatures of up to about 140° C. to yield higher molecular weight polymer products which are essentially free of gel, and which possess excellent green strength and processability.