Silver halide photographic emulsion containing cyanine and hemicyanine sensitizing dyes

Abstract

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 1 and Z 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 3 has the same meaning as Z 1 and Z 2 ; Z 4 represents a group of atoms necessary for forming an imidazole nucleus or an oxazole nucleus; Z 5 represents a group of atoms necessary for forming an imidazole nucleus; R 1 , R 2 , R 4 , R 5 and R 7 , which may be the same or different, each represents an alkyl group, with at least one of R 1 , R 2 , R 4 and R 5 being an alkyl group substituted with a carboxy group, a hydroxy group or a sulfo group; R 3 and R 6 , which may be the same or different, each represents a lower alkyl group, an aryl group or a hydrogen atom; R 8 represents a hydrogen atom or an alkylene group necessary for forming a ring through a combination with R 7 ; R 9 represents an aryl group (including a monocyclic aryl group and a bicyclic aryl group); X 1 - , X 2 - and X 3 - 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.

Inventors

• 👤 Akira Sato
• 👤 Tadashi Ikeda
• 👤 Takeo Sakai
• 👤 Haruo Takei
• 👤 Jun Hayashi

Bibliographic Details