Patents by Inventor Karl Wilhelm Leonhard

Karl Wilhelm Leonhard 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).

  • Manufacture of hexamethylene diamine
    Patent number: 3972938
    Abstract: A process for the catalytic hydrogenation of adiponitrile in the presence of ammonia, in which a portion of the reaction mixture is recycled and specific molar ratios of adiponitrile and ammonia are maintained.
    Type: Grant
    Filed: March 11, 1974
    Date of Patent: August 3, 1976
    Assignee: BASF Aktiengesellschaft
    Inventors: Dieter Voges, Leopold Hupfer, Siegfried Winderl, Karl Wilhelm Leonhard, Herwig Hoffmann