Spectrally-sensitized silver halide emulsion, useful in photographic material, e.g. color photographic camera or copying material, is supersensitized with 1-substituted 5-oxo-, 5-thio- or 5-imino-dihydro-1,2,4-triazole compound

摘要

Spectrally-sensitized silver halide emulsion is super-sensitized by adding a 1-substituted 5-oxo-, 5-thio- or 5-imino-dihydro-1,2,4-triazole (I). Spectrally-sensitized silver halide emulsion is super-sensitized by adding a 1-substituted 5-oxo-, 5-thio- or 5-imino-dihydro-1,2,4-triazole of formula (I); R1 = an aromatic or heterocyclic group; R2 = hydrogen (H), alkyl, aryl or acyl; R3 = alkyl, aryl, hetaryl or a carboxylic or phosphonic acid group; R4 = H, alkyl, aryl or a heterocyclic group; X = oxygen (O), sulfur (S) or imino R5 ; R5 = H, alkyl, aryl, hetaryl or acyl; R2 and R3 and/or R3 and R4 may = a group forming another 5-7-membered ring.