Patents by Inventor Kiichi Hattori

Kiichi Hattori 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 the purification of 4,4'-diamino-diphenylmethane
    Patent number: 5312989
    Abstract: A method of purifying 4,4'-diaminodiphenylmethane comprising partially melting a crystal of crude 4,4'-diaminodiphenylmethane and removing a melt to obtain a high purity 4,4'-diaminodiphenylmethane. By utilizing the method, a high purity 4,4'-diaminodiphenylmethane is obtained efficiently with a low level of energy consumption.
    Type: Grant
    Filed: May 28, 1993
    Date of Patent: May 17, 1994
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Takahiro Yamamoto, Hirokazu Murata, Kiichi Hattori