Photographic silver halide elements comprising infrared sensitizing dyes

摘要

Silver halide photographic element comprising a support and at least one silver halide emulsion layer, characterised in that said silver halide emulsion layer is spectrally sensitized to infrared radiation with a tricarbocyanine dye having the formula: wherein, Z1 and Z2 each independently represents the atoms necessary to complete a thiazole nucleus or an oxazole nucleus, Z3 represents the atoms necessary to complete a 5-membered N-containing aromatic ring, Q represents the atoms necessary to complete a 5- or 6-membered carbocyclic ring, R1 and R2 each independently represents an alkyl group, X- represents an anion, and n represents an integer of 1 to 2, provided that n is 1 when the dye forms an intramolecular salt.