METHOD FOR CHEMICAL SENSITIZATION OF HALOGEN-SILVER PHOTOGRAPHIC EMULSIONS Russian patent published in 1995 - IPC

FIELD: production of photographic materials. SUBSTANCE: Na₂S₂O₃·10 H₂O or allyl thiourea of complex compound of Au and polyamine polyacetic acid having common formula AuHal or AuH_yLHal where L is anion of ethylene-diamine-N-N′-diacetic, ethylene-N,N,N′, N′-tetracetic, trans-1,2-cyclohexane diamine-N,N,N′, N′-tetracetic or triethylene-tetramine-N,N,N′, N′′, N′′′, N′′′-hexacetic acids, Hal is Cl or Br, y=2 or 4 are added into photographic emulsion. Quantity of adding compound is 1,44·10^-7-1,2·10^-2 M/M AgHal. 2·10^-7-2·10^-4 M/M AgHal of polyamine polyacetic acid are added into said emulsion before mentioned above complex compound of Au is added. Method enables to increase photosensitivity by 5-20 while density of fog decreases by 20-50 EFFECT: increases photosensitivity, decreases density of fog. 2 cl, 3 tbl