Patents by Inventor Norbert Etzenbach

Norbert Etzenbach 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 producing iron oxide pigments
    Patent number: 6503315
    Abstract: The present invention relates to a process for producing iron oxide red pigments containing the step of forming a suspension of haematite nuclei by reaction between dilute nitric acid and elemental iron above 90° C. and to pigments of pure color and their use.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: January 7, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Norbert Etzenbach, Kai Bütje