Patents by Inventor Horst Viola

Horst Viola 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 of sensitizing silver halide emulsion with a dithioester
    Patent number: 4030928
    Abstract: Method for increasing the sensitivity of a photographic silver halide-gelatin emulsion comprising at the beginning of the chemical ripening adding to the emulsion of a dithioester of the formula: ##STR1## in which R is alkyl, .alpha.-hydroxyalkyl, .alpha.-hydroxyaralkyl, condensed aryl, or o- or p-substituted phenyl or .alpha.-naphthyl, the o- or p- located substituent being a F, OH, dialkylamino, sulfo, phenyl, phenylazo or anilidocarbonyl group and R.sub.1 is alkyl or aralkyl.
    Type: Grant
    Filed: November 18, 1975
    Date of Patent: June 21, 1977
    Assignee: VEB Filmfabrik Wolfen-Fotochemisches Kombinat
    Inventors: Siegfried Gahler, Karl-Wilhelm Junge, Gunther Fischer, Steffen Scheithauer, Horst Viola