Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a combination of two or more hydrazide nucleating agents in the emulsion layer and/or a hydrophilic colloid layer, characterized in that the combination comprises a nucleating agent(s) of formulae (I) and/or (I) with a nucleator of formula (III), in which the nucleating agent of formula (I) comprises (a) two nicotinamide moieties, which may be the same or different, which are linked by a linking group, and (b) a hydrazide moiety linked to only one of those nicotinamide moieties; the nucleating agent of formula (II) comprises a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises a hydrazide moiety and a nicotinamide moiety; and the nucleating agent of formula (III) comprises an aryl sulfonamido aryl hydrazide.

Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a combination of two or more hydrazide nucleating agents in the emulsion layer and/or a hydrophilic colloid layer, characterized in that the combination comprises a nucleating agent(s) of formulae (I) and/or (I) with a nucleator of formula (III), in which the nucleating agent of formula (I) comprises (a) two nicotinamide moieties, which may be the same or different, which are linked by a linking group, and (b) a hydrazide moiety linked to only one of those nicotinamide moieties; the nucleating agent of formula (II) comprises a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises a hydrazide moiety and a nicotinamide moiety; and the nucleating agent of formula (III) comprises an aryl sulfonamido aryl hydrazide.

Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a hydrazide nucleating agent in the emulsion layer or a hydrophilic colloid layer, characterised in that the nucleating agent of formula (I) comprises (a) two nicotinamide moieties, which may be the same or different, which are linked by a linking group, and (b) a hydrazide moiety linked to only one of the nicotinamide moieties. The nucleator of formula (I) may be in combination with a nucleator of formula (II) which comprises a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises a hydrazide moiety and a nicotinamide moiety. The photographic material provides unexpectedly good nucleation in the absence of, or with reduced amounts of, booster and in a developer whose pH is variable, and further with lower chemical spread and pepper fog.

Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a hydrazide nucleating agent in the emulsion layer or a hydrophilic colloid layer, characterized in that the nucleating agent is a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises an acylhydrazide moiety and a nicotinamide moiety in combination, the material providing unexpectedly good nucleation in the absence of, or with reduced amounts of, booster and in a developer whose pH is variable, and further with lower chemical spread and pepper fog.

Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a hydrazide nucleating agent in the emulsion layer or a hydrophilic colloid layer, characterised in that the nucleating agent is a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises an acylhydrazide moiety and a nicotinamide moiety in combination, the material providing unexpectedly good nucleation in the absence of, or with reduced amounts of, booster and in a developer whose pH is variable, and further with lower chemical spread and pepper fog.

Abstract: A photosensitive photographic silver halide material comprising a support bearing a layer of a silver halide emulsion comprising at least 50% silver chloride which contains in or adjacent the emulsion layer a hydrazide nucleating agent and an amine booster, the combination of which is capable of providing high contrast images, which emulsion is sensitised with a dye of the general formula: ##STR1## wherein each of R.sup.1 and R.sup.2 are individually hydrogen, or halogen atom or an alkyl group of 1-4 carbon atoms, a sulfoalkyl, a trifluoromethyl, or cyano group, R.sup.3 is an alkyl or substituted alkyl group, R.sup.4 is a sulfoalkyl group, and R.sup.5 and R.sup.6 are individually an alkyl or substituted alkyl group, andwherein there is the necessary counter-ion.

Abstract: High contrast graphic arts photographic materials exhibiting improved accuracy in image reproduction are comprised of a support, a silver halide emulsion layer having a chloride content of at least 50 mole percent, and a non-electroconductive hydrophilic colloid layer containing both a vinyl polymer and a hydrophilic colloid interposed between the support and the silver halide emulsion layer. A hydrazine nucleating agent is incorporated in or adjacent to the silver halide emulsion layer and the photographic material preferably also contains an amino compound which functions as a booster.