Patents by Inventor Georgios Zographos

Georgios Zographos 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).

  • Electrophotographic imaging process using anthraquinoid black pigments or metal complexes
    Patent number: 4191566
    Abstract: An electrophotographic imaging process, wherein the electrically photosensitive particles for the image reproduction consist of a black pigment selected from the series of the anthraquinoid pigments which contain at least 2 anthraquinone radicals or at least 6 condensed rings, of the perylenetetracarboxylic diimides or of the metal complexes of the formula ##STR1## wherein A represents a nitrogen atom or the ##STR2## X represents a hydrogen or halogen atom or an alkyl group of 1 to 6 carbon atoms,Y represents a hydrogen or halogen atom, an alkyl, alkoxy or alkylsulphonyl group of 1 to 6 carbon atoms, a nitro or carbamoyl group, an alkylcarbamoyl or alkoxycarbonyl group of 2 to 6 carbon atoms or an arylcarbamoyl or aryloxycarbonyl group of 7 to 11 carbon atoms.
    Type: Grant
    Filed: January 31, 1978
    Date of Patent: March 4, 1980
    Assignee: Ciba-Geigy Corporation
    Inventors: Remy Jeanneret, Gunther Zwahlen, Christoph Frey, Georgios Zographos