Patents by Inventor Kei Tsukahara

Kei Tsukahara 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 for producing conjugated diene polymer
    Patent number: 6071845
    Abstract: A catalyst obtained by contacting (A) a compound of a transition metal of the group V of the Periodic Table represented by formula (I):R.sub.n M(O).sub.m X.sub.p .cndot.L.sub.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: June 6, 2000
    Assignee: Ube Industries, Ltd.
    Inventors: Nobuhiro Tsujimoto, Michinori Suzuki, Kei Tsukahara, Shigeru Ikai, Koji Imaoka, Yoshiyuki Kai, Jun Yamashita
  • Process for producing polybutadiene
    Patent number: 5905125
    Abstract: A high cis-1,4-polybutadiene is produced, with reduced gel formation, by preparing a catalyst from (A) a cobalt compound, (B) a trialkyl (C.sub.1-10) aluminum compound, (C) a halide compound selected from those of formulae (1) and (2): (1) AlR.sup.2.sub.m X.sub.3-m, and (2) R.sup.3 --X, wherein R.sup.2 =C.sub.1-10 hydrocarbon, X=halogen, m=0 to 2, R.sup.3 =C.sub.1-40 hydrocarbon, and (D) water in an amount of 0.77 to 1.45 moles per mole of total Al in components (B) and (C); and polymerizing 1,3-butadiene in the presence of the resultant catalyst in a polymerization medium including an alkane, cycloalkane and/or olefin hydrocarbon.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: May 18, 1999
    Assignee: UBE Industries, Ltd.
    Inventors: Nobuhiro Tsujimoto, Takefumi Yano, Kazuhiro Akikawa, Chikara Kotani, Kei Tsukahara