Patents by Inventor Choju Nagata

Choju Nagata 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: 6221322
    Abstract: Low-cost, high-purity strontium nitrate that is low in Ba, Na, Ca, Cr, and other impurities and that is suitable for use in airbags or the like is provided. High-purity strontium nitrate having a Ba content of 0.01 wt % or lower, an Na content of 0.005 wt % or lower, a Ca content of 0.01 wt % or lower, a Cr content of less than 0.001 wt %, and a purity of 99.5 wt % or higher is produced by a manufacturing method comprising a first step for performing crystallization by adding nitric acid to an aqueous solution obtained by dissolving a strontium compound as a starting material, a second step for separating the resulting crystals, a third step for crystallizing the resulting separated solution, and a fourth step for separating the resulting crystals.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: April 24, 2001
    Assignees: Dowa Mining Co., LTD, Dowa Hightech Co., LTD
    Inventors: Tatsumi Inamura, Atsushi Tsukada, Kazunari Suzuki, Choju Nagata
  • Patent number: 6183875
    Abstract: An electronic circuit substrate including an aluminum-ceramic composite material having an electronic circuit formed on aluminum or an aluminum alloy plate of the aluminum-ceramic composite material which is prepared directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: February 6, 2001
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Xiao-Shan Ning, Choju Nagata, Masami Sakuraba, Toshikazu Tanaka, Katsuaki Suganuma, Masami Kimura
  • Patent number: 6121178
    Abstract: Sintered ITO having a relative density of at least 88% and an oxygen content of 15.5-17.0 wt %, as well as an ITO sputtering target made of this sintered ITO. Using the target, an optimal range for the proportion of oxygen in a mixture of argon and oxygen gases used as a sputtering atmosphere is sufficiently expanded to permit the consistent formation of ITO films.
    Type: Grant
    Filed: October 2, 1997
    Date of Patent: September 19, 2000
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Kohichiro Eshima, Kouki Toishi, Katsuaki Okabe, Tsuyoshi Nishimura, Shinji Sato, Choju Nagata
  • Patent number: 6099982
    Abstract: The starting salts for ITO production, precipitant and the conditions for reaction, calcination, etc. are specified such as to synthesize a starting oxide adapted to be free from volatile components such as halides and lower oxides; the starting oxide is dispersed to particles having a specified flowability; the powder is pressed into a compact, which is sintered in either air atmosphere or an oxygen-rich atmosphere to produce a large and high-density sinter for use as an ITO sputtering target.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: August 8, 2000
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Katsuaki Okabe, Tsuyoshi Nishimura, Shinji Sato, Kohichiro Eshima, Kouki Toishi, Choju Nagata
  • Patent number: 6077496
    Abstract: The mixed powders of a lithium compound and a transition metal based compound are formed into shaped parts, which are packed to form a bed 6 on a porous plate 5 in the bottom of a reaction vessel 7 placed on a support 10 in a firing furnace 8 equipped with an electric heater; the packed parts are fired with an oxidizing gas such as air being forced through the bed 6 at a superficial velocity higher than a specified value via a gas feed pipe 3 connecting an air pump 1, a flow regulator 2 and a preheater 4 and the gas emerging from the bed 6 is discharged into the air atmosphere through a ventilation port 9. Even if increased amounts of the mixed powders have to be fired, the invention process enables the production of a lithium complex oxide as an active material that is homogeneous and which features excellent cell characteristics.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: June 20, 2000
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Yuichi Ito, Yukio Hiraoka, Akinobu Iikawa, Masaru Nishisako, Choju Nagata, Kenichi Harigae
  • Patent number: 5965193
    Abstract: Molten aluminum and a ceramic substrate are held in direct contact with each other and thereafter cooled to have the aluminum joined directly to the ceramic substrate. This method is capable of consistent and easy production of aluminum-ceramics composite substrates having satisfactory joint strength, thermal conductivity and heat resistance characteristics. A ceramic member is fed successively into and through molten metal to directly bond the metal on the ceramic to produce a metal-bonded-ceramic (MBC) material at a low cost. An electronic circuit substrate made of an aluminum ceramic composite material wherein an electronic circuit is formed on an aluminum surface of the aluminum-ceramic composite material. The aluminum-ceramic composite material is made by directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: October 12, 1999
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Xiao-Shan Ning, Choju Nagata, Masami Sakuraba, Toshikazu Tanaka, Katsuaki Suganuma, Masami Kimura