PROCESS OF MANUFACTURE OF AMMONIA BROMINE-IODINE-SILVER PHOTOGRAPHIC EMULSION Russian patent published in 1995 - IPC

FIELD: manufacture of photographic materials. SUBSTANCE: process of manufacture of ammonia bromine-iodine-silver photographic emulsion with size of microcrystals of 1.0 ± 0.1 μm and content of silver iodide 4-0.1 mole per cent involves fractional emulsification, physical maturing, separation of solid phase with sulfopolysterene, washing of deposit, its dispersion in distilled water, adjustment of pBr up to 2,8± 0,1 and of pH up to 6,7± 0,1, chemical maturing with the use of stage of repeat dispersion of latex based on copolymer of butylacrylate and styrene in proportion 7:1 or copolymer of butylacrylate, styrene and metacrylic acid in proportions 7.0:0.5:0.5; 6.0: 1.5: 0.5; 5.0:2.5:1.5; 1.9:0.5:0.5 in the amount of 5.6-18.9 g/kg of emulsion. EFFECT: improved quality of photographic emulsion. 1 tbl