Patents by Inventor Kazuo Nakayasu

Kazuo Nakayasu 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).

  • Process for production of hydantoin derivatives
    Patent number: 4672127
    Abstract: Hydantoin derivatives are industrially advantageously produced at a high yield by reacting hydantoin with carbonyl compounds in the presence of (i) amino acids or the salts thereof and (ii) inorganic alkali compounds for a relatively short reaction time in an aqueous medium.
    Type: Grant
    Filed: July 30, 1985
    Date of Patent: June 9, 1987
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Jun Tanaka, Kazuo Nakayasu
  • Process for separating iminodiacetic acid from aqueous glycine solution
    Patent number: 4299978
    Abstract: A novel separation process of an iminodiacetic acid component from an aqueous glycine solution including the same is provided. In this process, sulfuric acid is added, in the presence of sodium salt, to the aqueous glycine solution in such an amount that the pH of the aqueous glycine solution becomes 1.5 or less, whereby the iminodiacetic acid is crystallized from the solution and, then, the crystallized iminodiacetic acid component is separated from the mother liquor. Thus, glycine can be efficiently recovered without causing undesirable accumulation of the iminodiacetic acid component in the mother liquor.
    Type: Grant
    Filed: August 21, 1980
    Date of Patent: November 10, 1981
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kazuo Nakayasu, Osamu Furuya, Yoshihiko Hosaki