Patents by Inventor Walter Kunstmann

Walter Kunstmann 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 the preparation of triamino benzenes by catalytic hydrogenation of 2,4-dinitro anilines
    Patent number: 4141917
    Abstract: 1,2,4-TRIAMINO BENZENES ARE OBTAINED IN HIGH YIELD AND PURITY BY CATALYTIC HYDROGENATION OF 2,4-DINITRO ANILINES IN WATER CONTAINING AT LEAST ONE MOLAR EQUIVALENT OF A MONO- OR DI-CARBOXYLIC ACID. The products are known and useful as intermediates for dyes and biocides.
    Type: Grant
    Filed: November 6, 1975
    Date of Patent: February 27, 1979
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Kunstmann, Bernhard Mees
  • Monoazo pigments from diazotized acylamino-anilines and acetoacetylamino benzimidazolones
    Patent number: 4080321
    Abstract: Monoazo compounds obtained by diazotising meta- or para-acylamino anilines and coupling on acetoacetylamino benzimidazolones are pigments of excellent fastness properties.
    Type: Grant
    Filed: March 16, 1976
    Date of Patent: March 21, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Kunstmann, Wolfgang Rieper
  • Dis-azo pigments deriving from bis-diazotized diamino-2-phenyl-benzazolones
    Patent number: 4024125
    Abstract: Pigments of the general formula ##STR1## wherein x is sulfur, oxygen or --NR--, R is hydrogen or alkyl of 1 to 4 carbon atoms, A is ##STR2## Y.sub.1, Y.sub.2, Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, Z.sub.5, Z.sub.6 and Z.sub.7 are hydrogen, chlorine, bromine, methyl, ethyl, methoxy or ethoxy. These new disazo pigments can be used in all fields of dyeing where pigments are typically used. They are distinguished by improved fastness properties and tinctorial strength.
    Type: Grant
    Filed: October 29, 1975
    Date of Patent: May 17, 1977
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Kunstmann, Joachim Ribka