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

FIELD: photographic industry. SUBSTANCE: silver bromide/iodide photographic emulsions suitable for negative black-and-white photographic materials are manufactured using controlled two-jet emulsifying by simultaneously introducing into ammonia-obtaining water-gelatin solution equinormal amounts of KBr/KI aqueous solution and silver nitrate aqueous solution at pBr 2.8-3.5 followed by separating solid phase, washing precipitate, dispersing it in water- gelatin solution, and chemical stabilization by way of successively introducing sodium thiosulfate, sodium benzenesulfinate, and gold- hydrochloric acid. According to invention, in the emulsifying stage, water-gelatin solution or KBr/KI aqueous solution is supplemented with 2-amino-5-imidazolpropionic acid and, in the chemical sensitizing stage, the latter is introduced into emulsion before of after sodium thiosulfate or gold-hydrochloric acid is added. EFFECT: improved procedure. 1 tbl