摘要:
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. When the synthesis provides both a compound of formula (I) and (II), the products can be used directly without a separation step, providing a cost advantage.
摘要:
Disclosed is a color photographic element comprising at least one light sensitive silver halide emulsion layer containing a compound that does not react with oxidized developer, has a Log Kow high enough to improve speed, compared to the same layer without the compound, and comprises (1) a thiadiazole, or (2) an oxadiazole, or (3) a 1,2,4 triazole bearing an amido substituent, and does not contain a hydroxyl or thiol group or their tautomeric equivalents on the azole ring.