METHOD FOR ISOLATION OF SOLID PHASE OF SILVER HALIDE PHOTOGRAPHIC EMULSIONS Russian patent published in 1997 - IPC

FIELD: photographic materials and processes. SUBSTANCE: invention may be used in chemical-photographic industry when preparing emulsions destined for recording UV emission, charged particles, and visible light and is aimed at increasing sensitivity and (i) decreasing optical density of optical fog of silver bromide emulsions for recording UV emission, (ii) decreasing dichroic coloration of emulsion layer, grain background of optical fog, and regression of hidden image of silver bromide-iodide emulsions for recording charged particles, and (iii) decreasing optical density of optical fog and increasing resolution of emulsions for air photographing, as well as simplification of process. To achieve this goal, isolation of solid phase from emulsion is carried out with introducing therein sodium dodecyl sulfate, or sulfanol, or sulfanolstyrene, or sodium polyvinyl sulfate, and disubstituted ammonium, potassium or sodium phosphate in quantity 0.35-1 g per 1 g of gelatin. This results in up to 50% increase in sensitivity and 30- 50% decrease in optical fog density when preparing UV emulsion; 1.5-2 times decrease in dichroic coloration of photographic layers, 30-50% decrease in grain background of optical fog and 60-75% in regression of hidden image of emulsion when recording charged particles; 2 times decrease in optical fog density and 22% decrease in resolution of emulsion when fulfilling air photographing. In addition, viscosity of emulsion is reduced by 1.5-3.5 times which facilitates preparing photographic materials. EFFECT: improved characteristics of photographic material. 4 tbl