UV-absorbent compounds, process for their preparation and their use as image dyes in photographic materials for the silver dye bleach process
AssigneeCiba-Geigy Corporation
InventorsThomas-Markus Rohr, Jakob Kuhn
Life of this patent
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Abstract
Compounds of the formula (B--L).sub.m A--L'--B').sub.n (1), in which A is the radical of a bisazo or trisazo dye, L and L' are organic radicals and B and B' are cyclic organic radicals and at least one of the radicals B and B' has spectral absorption in the UV region and one of the radicals B and B' is different from 2,4-dihydroxyphenyl, m is 1 or 2 and n is 0, 1 or 2. The compounds are suitable for use as image dyes in photographic silver dye bleach materials.
Claims3
Photographic silver dye bleach material which contains in at least one silver halide emulsion layer or in a layer adjacent to it, a compound of the formula
- (B--L).sub.m A--L'--B').sub.n ( 1)
- in which A is the radical of a bisazo or trisazo dye, L and L' are identical or different from each other and denote bridge members, B and B' are identical or different from each other and denote aromatic radicals, at least one of the radicals B and B' having spectral absorption in the UV region, and m is 1 or 2 and n is 0, 1 or 2, provided that if n is 0, B has spectral absorption in the UV region.
Dependencies are inferred from the claim text.