METHOD OF SPECTRAL SENSITIZATION OF BROMIODESILVER PHOTOGRAPHIC EMULSIONS Russian patent published in 1995 - IPC

FIELD: production of photographic materials. SUBSTANCE: two tiacarbocyanine (I and II) dues and one oxacarbocyanine (III) dye of the formula , where in due Ia R = R₁= C₂H₅OH, R₂= H, R₃= R₄= OCH₃, A = C₂H₅, X = CH₃-C₆H₄-n-S(O)₂O^-; Ib R = (CH₂)₃-S(O)₂O^-+NH-C₅H₅, R₂= H; R₃-R₄= OCH₃, A = C₂H₅, X is absent; Ib R = (CH₂)₃-S(O)₂O^-, R₁= (CH₂)₃-S(O)₂O^-+NH(C₂H₅)₃, (R₂+R₃), R₄= OCH₃, A = C₂H₅, X is absent, in amount of 7,15-16,4·10^-5 mol/mol AgHal; in dye IIIa R = R₁= C₂H₅OH, R₂= R₃= R₄= H, A = CH₃, X = Cl; IIb R = (CH₂)₃S(O)₂O^-, R₁= (CH₂)₃-S(O)₂-O^-+NH-C₅H₅, R₂= R₃= R₄= H, A = CH₃, X is absent, in amount of 4,12-11,37·10^-5 mol/mol AgHal; IN dye III instead of sulfur in the cycle is oxygen, IIIa R = (CH₂)₃S(O)₂O^-, R₁= (CH₂)₃S(O)-O^-+NHC₆H₅, R₃= R₄= C₆H₅, R₂ and X is absent, in amount of 3,75-6,7·10^-5 mol/mol AgHal; IIIb R = R₁= A = C₂H₅, X = C₂H₅S(O)₂O^-, R₃= R₄= C₆H₅, R₂ is absent in amount of 4,05-4,08·10^-5 mol/mol AgHal; IIIb R = R₁= C₂H₅, A = CH₃, X = C₂H₄-S(O)₂O^-, R₃= R₄= C₆H₅, R₂ is absent, in amount of 4,01-4,03·10^-5 mol/mol AgHal.. EFFECT: enhanced emulsion speed. 3 tbl