Spectrally sensitized silver halide photographic emulsions

Abstract

an internal latent image type silver halide photographic emulsion which provides a direct positive image by surface development in the presence of a fogging agent and which is useful in a light-sensitive material for the diffusion transfer process, which emulsion is spectrally sensitized with a supersensitizing combination of at least one sensitizing dye represented by the following general formula (I) or (II) ##STR1## wherein Z.sub.1 represents a non-metallic atomic group necessary to complete a 5- or 6-membered heterocyclic ring; and R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group; ##STR2## wherein Z.sub.2 represents a non-metallic atomic group necessary to complete a 5- or 6-membered heterocyclic ring; R.sub.3 represents an alkyl group or an aryl group; R.sub.4 represents an alkyl group or a substituted alkyl group; R.sub.18 represents a hydrogen atom or an alkylene group necessary to complete a ring when R.sub.4 and R.sub.18 combine to form a ring; and Y represents an oxygen atom or .dbd.N--R.sub.19 wherein R.sub.19 represents a hydrogen atom, an alkyl group or an aryl group; and at least one sensitizing dye represented by the following general formula (III), (IV), (V), (VI) or (VII) ##STR3## WHEREIN V.sub.1, V.sub.2, W.sub.1 and W.sub.2, which may be the same or different, each represents a hydrogen atom, a halogen atom, a trifluoromethyl group, a cyano group, a carboxy group, an alkoxycarbonyl group, an aminosulfonyl group or an alkylsulfonyl group; R.sub.5, R.sub.6, R.sub.7 and R.sub.8, which may be the same or different, each represents an alkyl group or a substituted alkyl group; X.sub.1 represents an acid anion; and n.sub.1 represents 0 or 1; ##STR4## WHEREIN V.sub.1, V.sub.2, R.sub.5 and R.sub.6, which may be the same or different, each has the same meaning as defined in general formula (III); R.sub.9, R.sub.10 and R.sub.11, which may be the same or different, each represents an alkyl group or a substituted alkyl group; X.sub.2 represents an acid anion; n.sub.2 represents 0 or 1; and W.sub.3 and W.sub.4, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; ##STR5## wherein V.sub.1, V.sub.2, R.sub.5 and R.sub.6, which may be the same or different, each has the same meaning as defined in general formula (III); W.sub.5 and W.sub.6, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; R.sub.12 represents an alkyl group or a substituted alkyl group; X.sub.3 represents an acid anion; and n.sub.3 represents 0 or 1; ##STR6## wherein V.sub.3 and W.sub.7, which may be the same or different, each represents a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acyloxy group or a phenyl group; R.sub.13 represents an alkyl group; R.sub.14 and R.sub.15, which may be the same or different, each represents an alkyl group or a substituted alkyl group; X.sub.4 represents an acid anion; and n.sub.4 represents 0 or 1; ##STR7## wherein V.sub.4 represents a hydrogen atom, a halogen atom, an alkyl group, a hydroxy group, an acyloxy group or a phenyl group; Z.sub.3 represents an oxygen atom, a sulfur atom, a selenium atom or --CH.dbd.CH--; W.sub.8 and W.sub.9, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group or a phenyl group; R.sub.16 and R.sub.17, which may be the same or different, each represents an alkyl group or a substituted alkyl group; X.sub.5 represents an acid anion; and n.sub.5 represents 0 or 1.

Description