Patents by Inventor Kumi C. Jayaratne

Kumi C. Jayaratne has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Catalyst compositions for producing polyolefins in the absence of cocatalysts
    Patent number: 7501372
    Abstract: This invention relates to the field of olefin polymerization catalyst compositions, and methods for the polymerization and copolymerization of olefins, including polymerization methods using a supported catalyst composition. One aspect of this invention is the prepraration and use of a catalyst composition comprising a hydrocarbyl-substituted metallocene compound and a chemically-treated solid oxide for olefin polymerization processes. In another aspect, for example, this invention encompasses the preparation of a catalyst composition comprising (?5-cycloalkadienyl)2Zr(hydrocarbyl)2 complexes and sulfated alumina, but containing no organoaluminum or organoboron cocataysts, and further the use of this catalyst composition for polymerizing olefins.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: March 10, 2009
    Assignee: Chevron Phillips Chemical Company LP
    Inventors: Matthew G. Thorn, Qing Yang, Kumi C. Jayaratne
  • Catalysts for olefin polymerization
    Patent number: 7247594
    Abstract: This invention relates to the field of olefin polymerization catalyst compositions, and methods for the polymerization and copolymerization of olefins, including polymerization methods using a catalyst composition. One aspect of this invention is the formation and use of a catalyst composition comprising a transition metal compound and an activator for olefin polymerization processes.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: July 24, 2007
    Assignee: Chevron Phillips Chemical Co. LP
    Inventors: Kumi C. Jayaratne, Michael D. Jensen, Matthew G. Thorn, Max P. McDaniel, Paul Barbee, Qing Yang