Patents by Inventor Ernst Klappert

Ernst Klappert 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).

  • Monoazo pigment derived from acetoacetylamino benzimidazolone
    Patent number: 4370269
    Abstract: The compound of the formula: ##STR1## is a valuable pigment of high fastness properties and high covering power.
    Type: Grant
    Filed: March 12, 1976
    Date of Patent: January 25, 1983
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Friedrich W. Weingarten, Klaus Hunger, Ernst Klappert
  • Monoazo compounds from 1-aminobenzene-2-carboxylic acid derivatives and their use as colorants
    Patent number: 4287122
    Abstract: Valuable pigments are obtained by diazotizing 1-aminobenzene-2-(carboxylic acid methyl or ethyl ester)-5-(2',3'-dichloro-anilide) and coupling it onto 1-(2'-hydroxy-3'-naphthoylamino)-4-acetamino-benzene. The resulting pigments are then subjected to a thermal aftertreatment. These pigments show a high tinctorial strength, a pure shade, a high fastness to migration, especially to overlacquering, to light and weathering and a high heat stability.
    Type: Grant
    Filed: February 25, 1977
    Date of Patent: September 1, 1981
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus Hunger, Ernst Klappert, Konrad Lohe