Patents by Inventor Tadafumi Yokota

Tadafumi Yokota 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).

  • Production method of ketone compound
    Patent number: 7034188
    Abstract: A method for producing a ketone, particularly a macrocyclic ketone, from a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms by efficiently dehydrating and reducing the acyloin in a single reaction vessel. A method for producing a ketone compound, which comprises dehydrating and reducing an acyloin in the coexistence of an acid catalyst and a reduction catalyst and in the presence of hydrogen, particularly using a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms as the acyloin.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: April 25, 2006
    Assignee: Japan Energy Corporation
    Inventors: Tadafumi Yokota, Hiroshi Yano
  • Production method of ketone compound
    Publication number: 20040152922
    Abstract: A method for producing a ketone, particularly a macrocyclic ketone, from a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms by efficiently dehydrating and reducing the acyloin in a single reaction vessel. A method for producing a ketone compound, which comprises dehydrating and reducing an acyloin in the coexistence of an acid catalyst and a reduction catalyst and in the presence of hydrogen, particularly using a 2-hydroxycycloalkanone having from 12 to 18 carbon atoms as the acyloin.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 5, 2004
    Applicant: JAPAN ENERGY CORPORATION
    Inventors: Tadafumi Yokota, Hiroshi Yano
  • Process for producing .omega.-hydroxy fatty acids
    Patent number: 5191096
    Abstract: .omega.-Hydroxy fatty acids usable for the synthesis of medicaments, perfumes and polymers are produced by subjecting an alkali or alkaline earth metal salt of long-chain dicarboxylic acid monoester to a reduction with a borohydride compound or catalytic hydrogenating reduction treatment.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: March 2, 1993
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Tadafumi Yokota, Akio Watanabe
  • Method for purifying macrocyclic ketones
    Patent number: 4917783
    Abstract: A method for purifying a macrocyclic ketone is disclosed which comprises light-irradiating a macrocyclic ketone containing a macrocyclic diketone as an impurity. Preferably, the macrocyclic ketone as light-irradiated is treated with an active charcoal so as to elevate the purity of the resulting macrocyclic ketone. For light-irradiation, the macrocyclic ketone may be in the form of an alcohol solution.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: April 17, 1990
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Tadafumi Yokota, Hiroshi Okino