METHOD OF MANUFACTURING SILVER BROMIDE/IODIDE PHOTOGRAPHIC EMULSIONS Russian patent published in 1997 - IPC

FIELD: photographic industry. SUBSTANCE: silver bromide/iodide photographic emulsions are manufactured using controlled two-jet emulsifying at pBr 3.1 ± 0.1 by introducing into ammonia-containing water-gelatin solution KBr/KI aqueous solution and silver nitrate aqueous solution followed by physical recrystallization, precipitating and dispersing solid phase, chemical recrystallization in presence of sodium thiosulfate, sodium benzenesulfinate, and gold-hydrochloric acid, and spectral sensitizing. According to invention, water-gelatin solution, before the beginning of emulsifying, is supplemented with thiourea dioxide in quantity (3-16) 10^-8 mol per 1 g of gelatin, and ammonia content in gelatin solution is (0.9-3.8) 10^-3 per 1 g of gelatin. EFFECT: improved procedure. 1 tbl