Patents by Inventor Heinz Keilhauer

Heinz Keilhauer 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).

  • Preparation of aminoazo dyes
    Patent number: 5424403
    Abstract: Aminoazo dyes are prepared from the corresponding N-sulfomethylated aminoazo dyes by aqueous acid hydrolysis in the presence of amidosulfuric acid, urea or mixtures thereof.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: June 13, 1995
    Assignee: BASF Aktiengesellschaft
    Inventors: Rudolf Bermes, Heinz Keilhauer