Patents by Inventor Kimio Iwai

Kimio Iwai 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).

  • Purification of 2-keto-L-gulonic acid
    Patent number: 5202476
    Abstract: According to the present invention which comprises subjecting an aqueous solution of 2-keto-L-gulonic acid or its water-soluble salt containing an acid impurity, whose acidity is higher than that of 2-keto-L-gulonic acid, to contact with an anion-exchange resin, then allowing the 2-keto-L-gulonic acid or the water-soluble salt thereof to precipitate from the processed solution obtained by allowing the impurity to be adsorbed, 2KGA or its water-soluble salt of a high purity can be separated in a high yield from an aqueous solution of 2KGA or its water-soluble salt containing acid impurities with less number of steps as compared with conventional methods.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: April 13, 1993
    Assignee: Takeda Chemical Industries, Ltd.
    Inventors: Masahiko Tsuda, Kimio Iwai