PROCESS OF MANUFACTURE OF BROMINE-IODINE-SILVER PHOTOGRAPHIC EMULSION AND PHOTOGRAPHIC MATERIAL BASED ON IT Russian patent published in 2003 - IPC

FIELD: photographic chemistry, manufacture of various type of black-and-white photographic materials. SUBSTANCE: invention describes process of manufacture of bromine-iodine-silver photographic emulsion with tabulated microcrystals that includes preparation of suspension of nucleus microcrystals of silver iodide by way of double- jet injection into solution number one containing gelatin, ammonia and water of solution number two containing caustic silver and water and aqueous solution of iodide of alkali metal or ammonium with constant value of pJ=0.5-3.0, growth of microcrystals by double-jet injection into prepared suspension of additional quantity of solution number 2 and solution number three carrying bromide of alkali metal or ammonium and water with constant value of pBr=1.5-3.5 followed by Ostwald maturing with constant value of pBr and chemical sensitization conducted in presence of 3-ethyl-5-(1'-methyldihydro (1', 2')-pyridiliden-2')-tiazolidintion(2)on(4). 1-(3- acetoaminophenyl)-5-merkaptotetrazol, sodium salt of isobuthybenzoltiosulfoacid and dikalium salt of disulphohydroquinone in the amount 0.1-0.3 g/mole Ag, 1.0-3.0 g/mole Ag and 0.3-0.5 g/mole Ag correspondingly are injected 5-10 min before termination of chemical sensitization. Formula of invention describes halogen-carrying photographic material containing above-mentioned emulsion. Proposed process makes it feasible to raise sensitivity (S_0,85 = 38-1230 relative units) and physical and mechanical properties of photographic material. EFFECT: raised sensitivity and physical and mechanical properties of photographic material. 2 cl, 1 tbl