Patents by Inventor Aloys Kirsch

Aloys Kirsch 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 preparing pure substituted 2,5-diarylamino-terephthalates and the corresponding free acids
    Patent number: 4124768
    Abstract: 2,5-Diarylamino terephthalates are obtained in good yields and excellent purity when the aromatic nitro compound used for oxidizing the corresponding dihydro-2,5-diarylamino terephthalate contains the aromatic radical of said diarylamino groups, i.e. when the amine formed during the oxidation is that from which said diarylamino groups device. The products yield very pure quinacridone pigments and allow the synthesis of only one isomer of substituted quinacridones.
    Type: Grant
    Filed: September 22, 1976
    Date of Patent: November 7, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Aloys Kirsch, Otto Fuchs, Ernst Spietschka