Silver halide emulsion supersensitized with a merocyanine dye and a tertiary phosphine sulfide

摘要

Photographic silver halide emulsions are spectrally sensitized with neutral methine dyes (merocyanines, including openchain merocyanines and hemioxonoles) and the sensitization is increased and stabilized by the action of phosphine sulfides of the formula R1 ¦ S=P-R2 ¦ R3 wherein R1, R2 and R3 are alkyl, cycloalkyl, aralkyl aryl or heterocyclic groups attached to the phosphorus atom either directly or by connecting members as defined hereinafter.