Patents by Inventor Norio Serizawa

Norio Serizawa 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).

  • Method for producing 1-nitroanthraquinone
    Patent number: 4289706
    Abstract: Anthraquinone is nitrated using a mixed acid comprising sulfuric acid and nitric acid, the concentration of sulfuric acid being 70 to 76% by weight and the amount of nitric acid being 33 to 55% by weight based on the total weight of sulfuric acid and nitric acid, whereby 1-nitroanthraquinone is obtained in a high yield and a high purity.
    Type: Grant
    Filed: July 27, 1979
    Date of Patent: September 15, 1981
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Akira Fukasawa, Shinzaburo Masaki, Norio Serizawa