Patents by Inventor Rudolf Denninger

Rudolf Denninger 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).

  • Dye mixtures containing an oil-soluble dye and an acid-extractable dye
    Patent number: 4904765
    Abstract: Dye mixtures contain an oil-soluble dye and a dye of the formula ##STR1## where D is phenyl which is unsubstituted or substituted by methyl or methoxy, R is hydrogen or methyl, R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl and R.sup.2 is C.sub.3 - or C.sub.4 -alkyl.The mixtures according to the invention are preferably used for coloring and marking mineral oil products.
    Type: Grant
    Filed: July 14, 1987
    Date of Patent: February 27, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Bernd Derber, Rudolf Denninger