Patents by Inventor Siegfried Dzwonnek

Siegfried Dzwonnek 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).

  • Patent number: 6534254
    Abstract: A color photographic print material which contains a cyan coupler of the formula in which R1 means a hydrogen atom or an alkyl group, R2 means an alkyl, aryl or hetaryl group, R3 means an alkyl or aryl group, R4 means an alkyl, alkenyl, alkoxy, aryloxy, acyloxy, acylamino, sulfonyloxy, sulfamoylamino, sulfonamido, ureido, hydroxycarbonyl, hydroxycarbonyl-amino, carbamoyl, alkylthio, arylthio, alkylamino or arylamino group or a hydrogen atom, Z means a hydrogen atom or a group eliminable under the conditions of chromogenic development, X means S, NH or NR5 and R5 means an alkyl or aryl group, is simultaneously distinguished by good light and dark stability as well as by good color reproduction.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: March 18, 2003
    Assignee: Agfa-Gevaert
    Inventors: Günter Helling, Ralf Weimann, Siegfried Dzwonnek
  • Patent number: 6015654
    Abstract: A color photographic recording material which contains, on a support, at least one blue-sensitive silver halide emulsion layer with which a yellow coupler is associated, at least one green-sensitive silver halide emulsion layer with which a magenta coupler is associated, and at least one red-sensitive silver halide emulsion layer with which a cyan coupler is associated, as well as light-insensitive intermediate layers between the layers of different coloor-sensitivity, characterised in that it contains a pyrazolotriazole coupler as a magenta coupler in at least one green-sensitive silver halide emulsion layer, and in at least one of said layers it contains, as a DOP scavenger, a compound of formula I ##STR1## wherein X.sub.1,X.sub.2 represent a single bond, --O-- or --NR.sub.7 --,R.sub.1 represents hydrogen or a group which can split off under the conditions of chromogenic development,R.sub.2 represents hydrogen or --CO--X.sub.1 --R.sub.4,R.sub.3 represents hydrogen or --CO--X.sub.2 --R.sub.5,R.sub.4, R.sub.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: January 18, 2000
    Assignee: AGFA-Gevaert NV
    Inventors: Jorg Hagemann, Siegfried Dzwonnek