Patents by Inventor Yasushi Tohi

Yasushi Tohi 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).

  • Olefin polymerization catalyst, process for preparing olefin polymer, and olefin polymer
    Patent number: 6004897
    Abstract: The olefin polymerization catalyst of the invention is formed from a Group IVB transition metal compound represented by the following formula (I) and an organoaluminum oxy-compound or a compound which reacts with the transition metal compound to form an ion pair. In the olefin polymerization process of the invention using this catalyst or a catalyst formed from a Group IVB transition metal compound represented by the following formula (II) and an organoaluminum oxy-compound or a compound which reacts with the transition metal compound to form an ion pair, an olefin (co)polymer having a high molecular weight can be obtained with high polymerization activities, and besides an olefin copolymer having a high comonomer content can be obtained even if a comonomer is used in a small amount. ##STR1## wherein, M is a transition metal of Group IVB, at least one of R.sup.1 is an aryl group and the remainder is hydrogen or the like, R.sup.2 is hydrogen, an alkyl group or the like, R.sup.3 and R.sup.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: December 21, 1999
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Junichi Imuta, Masayasu Yoshida, Yasushi Tohi