Patent ID: 6713226
Filing Date: 2004-03-30
Classification: G03C

Abstract:
An ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing at least one hydrazide nucleating agent in the emulsion layer and/or a hydrophilic colloid layer, characterised in that the nucleating agent has the formula (I): whereineach A1 and each A2 is independently selected from the class consisting of a hydrogen atom, an unsubstituted or substituted acyl group and an alkyl- or aryl-sulfonyl group; each Y is independently selected from the class consisting of an unsubstituted or substituted aryl or heterocyclic ring or ring system; each X is independently selected from the class consisting of S&boxH;O, C, Câ€”NH and Câ€”O; each Lâ€² is independently selected from the class consisting of an unsubstituted or substituted alkylene group and an unsubstituted or substituted aryl or heterocyclic ring or ring system, linked to Z via an unsubstituted or substituted alkylene group, either directly or via a group selected from the class consisting of NR1COâ€”, NR1CONR2â€”, OCONR1â€” or NR1COOâ€”, wherein R1 and R2 are independently selected from the class consisting of a hydrogen atom and an unsubstituted or substituted alkyl group; each Z is independently selected from an unsubstituted or substituted group, ring or ring system attached via a heteroatom selected from the class consisting of sulfur, nitrogen, oxygen or phosphorus; each L is independently a divalent, trivalent or tetravalent linking group; p and each n are independently 0 or 1 k is an integer from 0 to 8; and m is an integer from 2 to 4 provided that when p is 0, n is 0 and m is 2; when p is 1, n is 0 or 1 and m is 2, 3 or 4; and T is a counterion or a salt forming acid.