Patents by Inventor Tatsuo Nakada

Tatsuo Nakada 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: 5763705
    Abstract: There are provided production methods of 1,1,1,3,3-pentafluoropropane characterized in that 1,1,1,3,3-pentafluoro-2,3-dichloropropane is reacted with hydrogen fluoride in the presence of a noble metal catalyst; of 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane characterized in that the halogenated propene indicated as general formula I is fluorinated in the presence of antimony trihalogenide and/or antimony pentahalogenide by hydrogen fluoride of mole ratio of or over five times the said antimony halogenide in a liquid phase; and of 1,1,1,2,3,3-hexachloropropene characterized in that 1,1,1,2,2,3,3-heptachloropropane is reacted with an aqueous solution of alkali metal hydroxide in the presence of a phase transfer catalyst. Therefore, an industrial manufacturing method which is possible to obtain the objective product easily at low cost and high yield can be provided.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: June 9, 1998
    Assignee: Daikin Industries Ltd.
    Inventors: Seiji Takubo, Hirokazu Aoyama, Tatsuo Nakada
  • Patent number: 5763703
    Abstract: Manufacturing method for hexafluorocyclobutene in which 1,2-dichlorohexafluorocyclobutane is dechlorinated using hydrogen in the presence of a metal oxide and/or silicon oxide catalyst. Manufacturing method for (Z)-1,2,3,3,4,4-hexafluorocyclobutane which carries out the hydrogen-adding reaction (hydrogen reduction) of the raw material, 1,2-dichlorohexafluorocyclobutane, in the presence of a rhodium catalyst, or which carries out vapor-phase hydrogen reduction of hexafluorocyclobutene in the presence of a palladium catalyst.Using this manufacturing method, hexafluorocyclobutene can easily be derived in a single step with high selectivity from 1,2-dichlorohexafluorocyclobutane which can be obtained readily and at a low cost. This method also produces a high yield of (Z)-1,2,3,3,4,4-hexafluorocyclobutane.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: June 9, 1998
    Assignee: Daikin Industries Ltd.
    Inventors: Tatsuo Nakada, Hirokazu Aoyama, Akinori Yamamoto
  • Patent number: 5714655
    Abstract: 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane is used as a raw material, to which not less than 4.5 equivalent parts of hydrogen are added to effect a hydrogenation reaction in the presence of a noble metal catalyst, particularly a palladium catalyst, by the vapor phase method to manufacture 1,1,1,3,3-pentafluoropropane. Further, propane, propene, and hexachloropropene, etc. are chlorofluorinated in the presence of a metal catalyst to produce 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane, then this compound is reduced with hydrogen in the presence of a noble metal catalyst to produce 1,1,1,3,3-pentafluoropropane. 2,2,3-trichloro-1,1,1,3,3-pentafluoropropane and 1,1,1,3,3-pentafluoropropane can thus be efficiently and economically produced.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: February 3, 1998
    Assignee: Daikin Industries, Ltd.
    Inventors: Akinori Yamamoto, Eiji Seki, Hirokazu Aoyama, Seiji Takubo, Tatsuo Nakada
  • Patent number: 5714654
    Abstract: A method is proposed for producing 1,1,1,3,3-pentafluoropropane, in which 1,1,3,3,3-pentafluoropropene is reduced at a temperature between 40.degree. C. and 300.degree. C. by reacting it with hydrogen in a gas phase in the presence of a palladium catalyst. Further, a method is proposed for producing 1,1,1,3,3-pentafluoropropane and/or 1,1,3,3,3-pentafluoropropene, in which the raw material 2-chloro-1,1,3,3,3-pentafluoropropene is hydrogenated especially at a temperature between 30.degree. C. and 450.degree. C. in the presence of a catalyst composed of at least one metal selected from palladium, platinum and rhodium. Further, a method is proposed of producing 1,1,3,3,3-pentafluoropropene, in which 1,1,1,3,3-pentafluoro-2,3-dichloropropane is dechlorinated by using hydrogen in the presence of a metal oxide catalyst. Based on these production methods, 1,1,1,3,3-pentafluoropropane and/or 1,1,3,3,3-pentafluoropropene can thus be produced with high yield rates.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: February 3, 1998
    Assignee: Daikin Industries Ltd.
    Inventors: Akinori Yamamoto, Eiji Seki, Hirokazu Aoyama, Tatsuo Nakada
  • Patent number: 5688379
    Abstract: The present invention provides a process for preparing a perfluoroalkyl bromide characterized by reacting a perfluoroalkyl iodide represented by the formula C.sub.n F.sub.2n+1 I wherein n is an integer of 6 to 10 with bromine in a light-transmitting reactor with exposure to light and heating at 120.degree. to 180.degree. C. while simultaneously removing IBr resulting as a by-product by separation of a layer.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: November 18, 1997
    Assignee: Daikin Industries, Ltd.
    Inventors: Yasuhisa Furutaka, Tatsuo Nakada, Kazuhiro Shimokawa, Yorisato Hisanaga, Souichi Ueda
  • Patent number: 5659093
    Abstract: There are provided production methods of 1,1,1,3,3-pentafluoropropane characterized in that 1,1,1,3,3-pentafluoro-2,3-dichloropropane is reacted with hydrogen fluoride in the presence of a noble metal catalyst; of 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane characterized in that the halogenated propene indicated as general formula I is fluorinated in the presence of antimony trihalogenide and/or antimony pentahalogenide by hydrogen fluoride of mole ratio of or over five times the said antimony halogenide in a liquid phase; and of 1,1,1,2,3,3-hexaohloropropene characterized in that 1,1,1,2,2,3,3-heptachloropropane is reacted with an aqueous solution of alkali metal hydroxide in the presence of a phase transfer catalyst. Therefore, an industrial manufacturing method which is possible to obtain the objective product easily at low cost and high yield can be provided.
    Type: Grant
    Filed: June 27, 1995
    Date of Patent: August 19, 1997
    Assignee: Daikin Industries Ltd.
    Inventors: Seiji Takubo, Hirokazu Aoyama, Tatsuo Nakada
  • Patent number: 5608128
    Abstract: The present invention provides a production method of obtaining the mixture of 1,1,1,4,4,4-hexafluoro-2,3-dichloro-2-butene, 1,1,1,4,4,4-hexafluoro-2-chloro-2-butene and 1,1,1,4,4,4-hexafluoro-2-butene (1,1,1,4,4,4-hexafluoro-2-butene compounds) by reacting at least one of butane, butene and butadiene with chlorine and HF in the presence of a suitable catalyst, and also a production method of obtaining 1,1,1,4,4,4-hexafluorobutane by reducing said products in the presence of a noble metal catalyst.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: March 4, 1997
    Assignee: Daikin Industries, Ltd.
    Inventors: Tatsuo Nakada, Hirokazu Aoyama, Seiji Takubo
  • Patent number: 5532418
    Abstract: A method of producing 1,1,1,2,3,3-hexafluoropropane in a characteristic process in which tetrafluorochloropropene is first obtained from the dechlorofluorination (removing ClF) of 1,1,1,2,2-pentafluoro-3,3-dichloropropane and/or 1,1,2,2,3-pentafluoro-1,3-dichloropropane by hydrogen in the presence of a metal oxide catalyst and then the product olefin is fluorinated in the presence of a catalyst. By this method, 1,1,1,2,3,3-hexafluoropropane, which is useful as an action fluid and so on and has a property to help preserving the environment, and an intermediate in its synthesis can be easily produced at low cost.
    Type: Grant
    Filed: March 1, 1995
    Date of Patent: July 2, 1996
    Assignee: Daikin Industries Ltd.
    Inventors: Tatsuo Nakada, Hirokazu Aoyama
  • Patent number: 5364991
    Abstract: 1,1,1,4,4,4-Hexafluorobutane is prepared by reducing 2-chloro-1,1,1,4,4,4-hexafluorobutene-2 with hydrogen in the presence of a hydrogenation catalyst containing an alloy which contains at least one first metal component selected from the group consisting of platinum and palladium and at least one second metal component selected from the group consisting of silver, copper, gold, tellurium, zinc, chromium, molybdenum and thallium. 1,1,1,4,4,4-Hexafluorobutane can be prepared in a high selectivity and a high yield.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: November 15, 1994
    Assignee: Daikin Industries, Ltd.
    Inventors: Eiji Seki, Hirokazu Aoyama, Tatsuo Nakada, Satoshi Koyama
  • Patent number: 5304654
    Abstract: A 2-nitroimidazole compound of the formula: ##STR1## wherein R.sub.f is a fluorine-containing organic group which has at least one fluorine atom on a carbon atom which bonds to the nitrogen atom of the imidazole ring or a carbon atom which bonds to said carbon atom and a radiosensitizer comprising said nitroimidazole derivative.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: April 19, 1994
    Assignees: Yasunori Nishijima, Daikin Industries, Ltd.
    Inventors: Tsutomu Kagiya, Mitsuyuki Abe, Seiichi Nishimoto, Yuta Shibamoto, Kazuhiro Shimokawa, Yorisato Hisanaga, Tatsuo Nakada, Toru Yoshizawa
  • Patent number: 4927941
    Abstract: A nitroazole derivative of the formula:NA--R.sub.f (I)wherein NA is 3-nitro-1,2,4-triazol-l-yl and R.sub.f is a fluorine-containing organic group which is useful as a radiosensitizer.
    Type: Grant
    Filed: June 9, 1988
    Date of Patent: May 22, 1990
    Assignee: Yasunori Nishijima & Daikin Industries Ltd.
    Inventors: Tsutomu Kagiya, Mitsuyuki Abe, Seiichi Nishimoto, Yuta Shibamoto, Kazuhiro Shimokawa, Yorisato Hisanaga, Tatsuo Nakada, Toru Yoshizawa