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 holography photographic materials are manufactured using emulsifying, gelatinization, washing, chemical recrystallization in presence of sodium thiosulfate and gold- hydrochloric acid, and optical sensitizing by sodium salt of 3-ethyl- 3'-γ-sulfopropyl-4-keto-4'-phenyl-5-(1"-γ- sulfopropyldihydroquinolidene-4"- ethylidene)thiazolinothiazolcyaninobetaine. According to invention, emulsifying is carried out using controlled two-jet crystallization until microcrystals with average size 0.045-0.05 mcm are obtained; physical recrystallization at pAg 8.6 γ 0.1 and temperature 45-47 C is performed after washing procedure until microcrystals with average size 0.07-0.08 mcm are obtained; before optical sensitizer is added, pAg value is adjusted to 8.6-8.8; and, after sensitizer is added, emulsion is supplemented with 2-heptyl-5-methyl-7-hydroxy-1,2,4- triazaindolicin. EFFECT: improved characteristics of emulsion. 1 tbl