Silver halide photographic emulsion containing cyanine and hemicyanine

Abstract

A spectrally sensitized silver halide photographic emulsion comprising a silver halide emulsion containing a combination of at least one sensitizing dye represented by the following general formula (I): ##STR1## at least one sensitizing dye represented by the following general formula (II): ##STR2## and at least one organic heterocyclic compound represented by the following general formula (III) or (IV): ##STR3## wherein Z.sup.1 and Z.sup.2, which may be the same or different, each represents a group of atoms necessary for forming a thiazole nucleus or a selenazole nucleus; Z.sup.3 has the same meaning as Z.sup.1 and Z.sup.2 ; Z.sup.4 represents a group of atoms necessary for forming an imidazole nucleus or an oxazole nucleus; Z.sup.5 represents a group of atoms necessary for forming an imidazole nucleus; R.sup.1, R.sup.2, R.sup.4, R.sup.5 and R.sup.7, which may be the same or different, each represents an alkyl group, with at least one of R.sup.1, R.sup.2, R.sup.4 and R.sup.5 being an alkyl group substituted with a carboxy group, a hydroxy group or a sulfo group; R.sup.3 and R.sup.6, which may be the same or different, each represents a lower alkyl group, an aryl group or a hydrogen atom; R.sup.8 represents a hydrogen atom or an alkylene group necessary for forming a ring through a combination with R.sup.7 ; R.sup.9 represents an aryl group (including a monocyclic aryl group and a bicyclic aryl group); X.sub.1.sup.-, X.sub.2.sup.- and X.sub.3.sup.- each represents an acid anion; m, n and p each represents 1 or 2, but when m, n or p is 1, the dye forms an intramolecular salt. The photographic emulsion exhibits a high sensitivity with a reduced fog and stain, and a good stability with the lapse of time during and after production, and further an improved latent image stability with the lapse of time of from image-wise exposure to development.