Patents by Inventor Ryouichi Tamai

Ryouichi Tamai 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: 6316681
    Abstract: The present invention relates to a method for producing 1,1,1,3,3-pentafluoropropane. This method includes a first step of fluorinating 1-chloro-3,3,3-trifluoropropene in a liquid phase by hydrogen fluoride in the presence of an antimony compound as a catalyst, or a second step of fluorinating 1-chloro-3,3,3-trifluoropropene in a gas phase by hydrogen fluoride in the presence of a fluorination catalyst. If the first step is taken, 1,1,1,3,3-pentafluoropropane can be produced with a high yield. If the second step is taken, 1,1,1,3,3-pentafluoropropane can continuously be easily produced. Therefore, the second step is useful for an industrial scale production thereof. According to the invention, 1-chloro-3,3,3-trifluoropropene may be produced by a method including a step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst. This method is useful, because yield of 1-chloro-3,3,3-trifluoropropene is high.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: November 13, 2001
    Assignee: Central Glass Company, Limited
    Inventors: Satoshi Yoshikawa, Ryouichi Tamai, Fuyuhiko Sakyu, Yasuo Hibino, Yoshihiko Gotoh
  • Patent number: 6235951
    Abstract: The present invention relates to a method for producing 1,1,1,3,3-pentafluoropropane. This method includes the steps of (a) adding hydrogen fluoride to 1-chloro-3,3,3-trifluoropropene in the presence of an addition catalyst to obtain 1,1,1,3-tetrafluoro-3-chloropropane; and (b) disproportionating the 1,1,1,3-tetrafluoro-3-chloropropane into the 1,1,1,3,3-pentafluoropropane and 1,1,1-trifluoro-3,3-dichloropropane, in the presence of a disproportionation catalyst. This method is a useful method for producing 1,1,1,3,3-pentafluoropropane in an industrial scale, because its steps (a) and (b) are respectively superior in selectivity and yield. According to the invention, 1-chloro-3,3,3-trifluoropropene may be produced by a method including a step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst. This method is useful, because yield of 1-chloro-3,3,3-trifluoropropene is high.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: May 22, 2001
    Assignee: Central Glass Company, Limited
    Inventors: Fuyuhiko Sakyu, Satoshi Yoshikawa, Yasuo Hibino, Yoshihiko Gotoh, Ryouichi Tamai
  • Patent number: 6198010
    Abstract: The present invention relates to a method for producing 1,1,1,3,3-pentafluoropropane. This method includes a first step of fluorinating 1-chloro-3,3,3-trifluoropropene in a liquid phase by hydrogen fluoride in the presence of an antimony compound as a catalyst, or a second step of fluorinating 1-chloro-3,3,3-trifluoropropene in a gas phase by hydrogen fluoride in the presence of a fluorination catalyst. If the first step is taken, 1,1,1,3,3-pentafluoropropane can be produced with a high yield. If the second step is taken, 1,1,1,3,3-pentafluoropropane can continuously be easily produced. Therefore, the second step is useful for an industrial scale production thereof. According to the invention, 1-chloro-3,3,3-trifluoropropene may be produced by a method including a step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst. This method is useful, because yield of 1-chloro-3,3,3-trifluoropropene is high.
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: March 6, 2001
    Assignee: Central Glass Company, Limited
    Inventors: Satoshi Yoshikawa, Ryouichi Tamai, Fuyuhiko Sakyu, Yasuo Hibino, Yoshihiko Gotoh
  • Patent number: 6120652
    Abstract: The invention relates to a method for purifying a crude 1,1,1,3,3-pentafluoropropane (HFC-245fa) containing HFC-245fa and 1-chloro-3,3,3-trifluoro-trans-1-propene (HCFC-1233zd(t)), by distillation. This method is characterized in that the distillation is conducted in the presence of a solvent having a boiling point which is higher than that of HCFC-1233zd(t), thereby to substantially remove HCFC-1233zd(t) from the crude HFC-245fa. This solvent may be selected from carbon chlorides, chlorohydrocarbons, fluorochlorohydrocarbons, saturated hydrocarbons, and mixtures thereof. With the use of this solvent, it becomes possible to substantially easily separate HFC-245fa from HCFC-1233zd(t).
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: September 19, 2000
    Assignee: Central Glass Company
    Inventors: Yasuo Hibino, Ryouichi Tamai
  • Patent number: 6111150
    Abstract: The present invention relates to a method for producing 1,1,1,3,3-pentafluoropropane. This method includes a step of adding hydrogen fluoride to 1,3,3,3-tetrafluoropropene in a liquid phase in the presence of a hydrohalogenation catalyst. This method is a useful method for producing 1,1,1,3,3-pentafluoropropane in an industrial scale, because yield of 1,1,1,3,3-pentafluoropropane is high. According to the invention, 1,3,3,3-tetrafluoropropene may be produced by a method including a step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst, or by another method including a step of reacting 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst. According to the invention, 1-chloro-3,3,3-trifluoropropene may be produced by a method including a step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: August 29, 2000
    Assignee: Central Glass Company, Limited
    Inventors: Fuyuhiko Sakyu, Yasuo Hibino, Satoshi Yoshikawa, Ryouichi Tamai, Yoshihiko Gotoh