Patents by Inventor Tsutomu Takashima

Tsutomu Takashima 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).

  • Patent number: 6476284
    Abstract: An efficient dehalogenation can be carried out by a method which comprises treating an organic compound containing a compound of halogen, such as fluorine or chlorine, as an impurity and having non-conjugated carbon-carbon double bonds, for example, butene polymer produced with a boron trifluoride catalyst, with an inorganic solid treating agent containing aluminum atoms. When the dehalogenation is conducted in the presence of a basic substance such as ammonia or an amine, it can be continued over long while inhibiting the isomerization of the non-conjugated carbon-carbon double bonds.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: November 5, 2002
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Koichi Ohashi, Tsutomu Takashima, Teruhisa Kuroki, Koji Fujimura, Yuichi Tokumoto
  • Patent number: 6462151
    Abstract: Boron trifluoride can be recovered in a reusable state by a method that is economical and does not cause environmental pollution, which method comprises the steps of bringing a fluid containing boron trifluoride or its complex into contact with metal fluoride so as to selectively adsorb and remove boron trifluoride in the complex and heating the resultant metal tetrafluoroborate at a temperature in the range of 100 to 600° C. to separate it into boron trifluoride and metal fluoride. By applying the method to a process for producing polybutene or olefin oligomer using boron trifluoride complex catalyst, the catalyst can be recovered with retaining its activity and reused effectively.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: October 8, 2002
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Tsutomu Takashima, Yuichi Tokumoto, Koji Fujimura
  • Patent number: 6300444
    Abstract: It is possible to produce butene polymer at high yield, which polymer contains 80 mol % or more of polymer molecules having terminal vinylidene structure and being low in the content of residual organic fluorine by a process comprising Step (I) to polymerize in liquid phase by adding complex catalyst composed of boron trifluoride, ether and alcohol and/or water in specified ratios to C4 fractions and Step (II) to reduce the content of trimer and lighter components contained in the obtained polymer to 0.2% by weight or less by distillation.
    Type: Grant
    Filed: April 15, 2000
    Date of Patent: October 9, 2001
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Yuichi Tokumoto, Koichi Ohashi, Toshio Okada, Tsutomu Takashima
  • Patent number: 6084144
    Abstract: A boron trifluoride complex can be recovered without changing its molar coordination ratio, by applying a direct and/or alternating voltage to an electrically-nonconductive fluid in which at least a part of boron trifluoride complex is dispersed and/or dissolved, and separating the boron trifluoride complex by settling from the electrically-nonconductive fluid. By utilizing this method for the preparation of olefin oligomer using a boron trifluoride complex catalyst, it is possible to reuse the recovered catalyst as it stands for the reaction.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: July 4, 2000
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Tsutomu Takashima, Yoshisuke Kakuyama, Shigeru Nishikida, Yuichi Tokumoto, Kouji Fujimura
  • Patent number: 5846429
    Abstract: A method for effectively separating and removing or recovering BF.sub.3 existing in a liquid hydrocarbon which is characterized in that an organic liquid mixture containing suspended or dissolved BF.sub.3 is brought into liquid phase contact with a synthetic polymer fiber containing nitrile groups at a temperature of C. or lower, so that the BF.sub.3 is adsorbed by the synthetic polymer fiber and it is then heated to C. or higher to recover the BF.sub.3.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: December 8, 1998
    Assignee: Nippon Petrochemicals Company, Limited
    Inventors: Isoo Shimizu, Yoshisuke Kakuyama, Tsutomu Takashima
  • Patent number: 5698023
    Abstract: This invention provides a process for producing copper phthalocyanine pigments which comprises reacting either phthalic anhydride or its derivatives with urea and a copper-containing substance, or either phthalonitrile or its derivative with a copper-containing substance in a reaction solvent by heating characterized in that an alkylxylene ingredient having a branched C4 side-chain represented by the following formula (1) is used as the reaction solvent: ##STR1##
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: December 16, 1997
    Assignee: Nippon Petrochemical Co., Ltd.
    Inventors: Tsutomu Takashima, Kikuo Sasaki, Hideyuki Dohi