Patents by Inventor Tadamitsu Kiyoura

Tadamitsu Kiyoura 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: 5959150
    Abstract: A process for preparing methylamines is disclosed herein which comprises the step of reacting methanol with ammonia in the presence of a mordenite in which the ratio of the length of mordenite crystals in a c axis direction to that of the mordenite crystals in an a axis direction or a b axis direction, c/a or c/b is 2 or more, whereby the synthetic activity of the methylamines can be maintained at a high level, and the production ratio of trimethylamine can be inhibited to a low level of about several percent to predominantly produce dimethylamine and monomethylamine.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: September 28, 1999
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Tadamitsu Kiyoura, Shigeki Nakahara
  • Patent number: 5608114
    Abstract: Upon subjecting trimethylamine with ammonia and optionally, a methylamine to a disproportioning reaction to reduce the proportion of the trimethylamine, use of a zeolite as a catalyst, said zeolite being mordenite, clinoptilolite or the like at least 80% of whose ion-exchangeable cations being in the form of hydrogen ions, makes it possible to efficiently conduct the reaction at a low reaction temperatures and also to suppress by-production of impurities such as acetonitrile.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: March 4, 1997
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventor: Tadamitsu Kiyoura
  • Patent number: 5382696
    Abstract: A method for selectively preparing dimethylamine and monomethylamine, while the production of trimethylamine is inhibited to a sufficiently low level. The method comprises carrying out a gaseous reaction of methanol and ammonia by the use of a mordenite modified with a silylating agent by a silylation treatment in a liquid phase. According to the present invention, recycling trimethylamine is unnecessary, and the amount of steam or the like to be used can be decreased.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: January 17, 1995
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadamitsu Kiyoura, Kazuhiro Terada
  • Patent number: 5336440
    Abstract: Methanol is decomposed in the presence of a catalyst containing chromium oxide and zinc oxide as main components and containing a compound of at least one element selected from the group consisting of alkali metals, alkali earth metals and lanthanides, while contents of iron and nickel in the catalyst are each maintained at 0.5% by weight or less. This process is characterized by (1) being excellent in stability at high temperatures, (2) preventing the catalyst from deteriorating, (3) inhibiting the production of by-products, and (4) obtaining a gas in which the CO/H.sub.2 ratio is high.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: August 9, 1994
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadamitsu Kiyoura, Takashi Jimbo, Yasuo Kogure, Kazuo Kanaya
  • Patent number: 5155235
    Abstract: A catalyst for producing maleic anhydride by oxidation of n-butane comprising V,P and additionally Mg or Zr is prepared by(a) heating a pentavalent vanadium compound in an organic medium to reduce at least a part of the pentavalent vanadium to tetravalent vanadium,(b) reacting the resulting vanadium compound with phosphoric acid in the presence of at least one of a magnesium compound and a zirconium compound to form a catalyst precursor,(c) separating the resulting catalyst precursor from the organic medium, and(d) drying and calcining the catalyst precursor.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: October 13, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Jimbo Takashi, Tadamitsu Kiyoura, Yasuo Kogure, Kazuo Kanaya
  • Patent number: 5147624
    Abstract: Chlorine can be efficiently produced at a low temperature and with a high hourly space velocity by oxidizing hydrogen chloride with an oxygen-containing gas in the presence of a catalyst obtained by calcining a compound, which has in turn been obtained by reacting chromium nitrate, chromium chloride, the chromium salt of an organic acid or the like with ammonia, or by calcining a mixture of the compound and a silicon compound, preferably, at a temperature lower than 800.degree. C.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: September 15, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadamitsu Kiyoura, Masanobu Ajioka, Naoshi Fujimoto, Toshihide Suzuki, Yasuo Kogure, Tokio Nagayama, Kazuo Kanaya
  • Patent number: 5032564
    Abstract: A cayalyst precursor is produced by reacting V.sub.2 O.sub.4 with phosphoric acid in an organic solvent in the presence of a polyol. The catalyst precursor is calcined to obtain a catalyst having a high density, highly attrition-resistance and a large specific surface area and requiring only a low temperature for the oxidation of butane.
    Type: Grant
    Filed: February 21, 1990
    Date of Patent: July 16, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadamitsu Kiyoura, Jimbo, Takashi, Yasuo Kogure, Kazuo Kanaya
  • Patent number: 4828815
    Abstract: Chlorine can be efficiently produced at a low temperature and with a high hourly space velocity by oxidizing hydrogen chloride with an oxygen-containing gas in the presence of a catalyst obtained by calcining a compound, which has in turn been obtained by reacting chromium nitrate, chromium chloride, the chromium salt of an organic acid or the like with ammonia, or by calcining a mixture of the compound and a silicon compound, preferably, at a temperature lower than 800.degree. C.
    Type: Grant
    Filed: December 10, 1987
    Date of Patent: May 9, 1989
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadamitsu Kiyoura, Masanobu Ajioka, Naoshi Fujimoto, Toshihide Suzuki, Yasuo Kogure, Tokio Nagayama, Kazuo Kanaya
  • Patent number: 4822589
    Abstract: In the process of producing chlorine by oxidizing hydrogen chloride with molecular oxygen, activity of the catalyst can be maintained for a long period with a high conversion ratio under high space velocity of gaseous raw materials without using additives as in conventional methods, in the presence of a crystalline chromic oxide catalyst obtained by supporting relatively large amounts of chromic oxide on a silicon oxide carrier having a specified pore volume.
    Type: Grant
    Filed: January 26, 1988
    Date of Patent: April 18, 1989
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Tadamitsu Kiyoura, Yasuo Kogure, Tokio Nagayama, Kazuo Kanaya
  • Patent number: 4599446
    Abstract: A process for the preparation of 2-keto-L-gulonic acid by the oxidation of L-sorbose with an oxygen-containing gas in water used as the solvent, wherein the reaction is carried out in the presence of a specific catalyst, preferably with the pH of the reaction fluid kept within the range of 6 to 10. The catalyst contains platinum and/or palladium, as well as lead or bismuth. 2-Keto-L-gulonic acid is a compound which is useful as a precursor of vitamin C.
    Type: Grant
    Filed: April 17, 1985
    Date of Patent: July 8, 1986
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventor: Tadamitsu Kiyoura
  • Patent number: 4476310
    Abstract: A process for the preparation of indoles which comprises reacting aniline or a derivative thereof with a 1,2-glycol in the presence of a catalyst comprising silver supported on a carrier having a specific surface area of not less than 10 m.sup.2 /g.
    Type: Grant
    Filed: June 9, 1982
    Date of Patent: October 9, 1984
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tadatoshi Honda, Fujio Matsuda, Tadamitsu Kiyoura, Kazuhiro Terada
  • Patent number: 4456760
    Abstract: A process for the preparation of indole and derivatives thereof wherein an aniline is reacted with a 1,2-glycol in the liquid phase in the presence of a catalyst containing metallic copper and/or copper oxide. The present ivention makes it possible to prepare indole and derivatives thereof in a single step by using inexpensive starting materials.
    Type: Grant
    Filed: May 5, 1982
    Date of Patent: June 26, 1984
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Fujio Matsuda, Takazo Kato, Tadamitsu Kiyoura
  • Patent number: 4247716
    Abstract: A novel process for producing pyruvic acid is provided in which process hydroxyacetone is oxidized with a molecular oxygen-containing gas in a water-containing or aqueous solvent in the presence of a catalyst. The catalysts useful for the above oxidation reaction are those composed of either at least one metal selected from the group consisting of platinum, palladium, rhodium, ruthenium, and rhenium, or the at least one metal admixed with at least one element selected from the group consisting of silver, tellurium, tin, bismuth, lead and indium or with a compound of the at least one element. The resulting pyruvate can be effectively isolated in the form of a solid by concentrating the reaction solution and adding the concentrate to isopropyl alcohol.
    Type: Grant
    Filed: August 11, 1978
    Date of Patent: January 27, 1981
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventor: Tadamitsu Kiyoura
  • Patent number: 4242525
    Abstract: A salt of pyruvic acid is formed by oxidizing a salt of lactic acid with an oxygen-containing gas in a water-containing solvent in the presence of a catalyst. The catalyst used herein comprises (a) at least one component selected from platinum and palladium and (b) at least one component selected from lead, tin, tellurium, indium, bismuth, and compounds of these elements. The resulting pyruvate is isolated in the form of a solid by concentrating the catalyst-free reaction mixture and then mixing isopropyl alcohol therewith.
    Type: Grant
    Filed: April 10, 1979
    Date of Patent: December 30, 1980
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventor: Tadamitsu Kiyoura
  • Patent number: 4227023
    Abstract: This invention relates to a process for the selective ortho-alkylation of a phenolic compound having at least one ortho-positioned a hydrogen atom by catalytically reacting the phenolic compound with an alcohol in the vapor phase. In this process, the reaction of the phenolic compound with the alcohol is carried out at a temperature of from 300.degree. to 550.degree. C. in the presence of a mixed oxide catalyst of manganese, silicon, and one or more additives selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide. The catalyst used in this invention exhibits not only excellent catalytic activity in the selective ortho-alkylation of phenols but also continuous stability of the activity, good shapability, and good mechanical strength.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: October 7, 1980
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Motoo Kawamata, Tadamitsu Kiyoura, Kazushi Ohshima, Yasuo Kogure, Akihide Kudoh, Makoto Kotani