Regeneration of exhausted silver bleach solutions by means of n-bromo compounds

Claim 1

IN THE PHOTOGRAPHIC PROCESS OF BLEACHING A METALLIC SILVER IMAGE TO SILVER HALIDE WITH A BLEACH SOLUTION COMPRISING AN ALKALI METAL BROMIDE AND AN ALKALI METAL FERRICYANIDE WHEREBY THE SILVER IN THE SILVER IMAGE IS OXIDIZED TO SILVER IONS WHICH COMBINE WITH THE HALIDE IONS OF THE SOLUTION AND FORM A SILVER HALIDE IN THE EMULSION AND A RELATIVELY SMALL AMOUNT OF THE FERROCYANIDE, AND THEN REGENERATING THE EXHAUSTED BLEACHING SOLUTION BY ADDING A REGENERATING AGENT THE IMPROVEMENT WHEREIN SAID REGENERATING AGENT IS A MATERIAL SELECTED FROM THE GROUP CONSISTING OF TERMINAL PRIMARY ALKYLAMINES, ALIPHATIC AND AROMATIC CARBONAMIDES, CARBONIMIDES, AROMATIC SULFONAMIDES, AND MELAMINE, IN WHICH TH RESPECTIVE AMINO, AMIDO AND IMIDO NITROGEN IS SUBSTITITED BY AT LEAST ONE BROMINE ATOM, THE AMOUNT OF SAID N-BROMO DERIVATIVE BEING SUCH AS TO RELEASE ABOUT ONE MOLAR EQUIVALENT OF BROMINE FOR EACH MOLAR EQUIVALENT OF FERROCYANIDE ION PRESENT IN IT EXHAUSTED BLEACH SOLUTION.