Patents by Inventor Mina Koyama

Mina Koyama 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).

  • &mgr;-oxo-bis-metallocene complex compounds and catalysts using same for the polymerization of olefins as well as polymerization process
    Patent number: 6426395
    Abstract: Disclosed are &mgr;-oxo-bis-metallocene complex compounds, catalysts for the polymerization of olefins comprising a &mgr;-oxo-bis-metallocene complex compound and at lease one cocatalyst selected from the group consisting of an aluminoxane, an ionic compound, and a Lewis acid, and a process for the polymerization of olefins. An example of the &mgr;-oxo-bis-metallocene complex compound is represented by the following formula (1): wherein, for example, M is zirconium, n is 1, Y is silicon, X is chloro, and R1-R10 maybe hydrogen or alkyl.
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: July 30, 2002
    Assignees: Chisso Corporation
    Inventors: Hiroshi Yamazaki, Masato Nakano, Seiki Mitani, Jun Saito, Masato Harada, Mina Koyama
  • Processes for the preparation of metallocene complexes
    Patent number: 6184402
    Abstract: Disclosed is a process for the preparation of metallocone complexes wherein stereoisomers of metallocene complexes formed at the time of synthesis can easily be separated. The gist of the present invention resides in separation of a part of an isomeric mixture of specific metallocene complexes bridged with a transition metal represented by the formula (1) as a complex having M—O bond. In particular, preferable is a process for separating a part of an isomeric mixture of a metallocene complex represented by the formula (2) as a &mgr;-oxo-complex represented by the formula (3).
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: February 6, 2001
    Assignee: Chisso Corporation
    Inventors: Hiroshi Yamazaki, Masato Nakano, Seiki Mitani, Jun Saito, Masato Harada, Mina Koyama