METHOD FOR PREPARATION OF HALOGEN-SILVER PHOTOGRAPHIC EMULSION Russian patent published in 2009 - IPC G03C1/05 G03C1/35 B82B3/00 

FIELD: physics, photography.

SUBSTANCE: invention is related to technology of preparation of photographic emulsions for camera photomaterials. In such technologies they often use method of microcrystal doping with ions of heavy metals to improve sensitometric characteristics of emulsion layers. Suggested method of photoemulsion manufacturing with application of doping consists in performance of double-jet crystallisation of silver nitrate and potassium bromide solutions, interruption of process, single-stage introduction of iridium compound solution as dopant and completion of double-jet crystallisation process. Besides process is interrupted for the period of 30-120 sec. before single-stage introduction and delay of 30-120 sec. after introduction of iridium compound solution. Iridium compounds used are complex compounds from the group K₂[IrBr₆], K₂[IrCl₆], K₂[IrBr₅Cl], K₂[lrCl₅Br] in concentration from 10^-7 to 10^-9 mole/mole Ag.

EFFECT: improved sensitometric characteristics due to increase of duration of electronic stage of hidden image centers creation and more efficient use of photoelectrons produced in process of exposure.

3 cl, 1 tbl, 15 ex