| 摘要 |
This application discloses a photographic element comprising an image dye-forming coupler, and in particular a yellow coupler with an indazole coupling-off group which produces images with improved sharpness and comprises a light sensitive silver halide emulsion layer containing an image-dye-forming coupler of formula (I)wherein:R is an alkyl, aryl, alkoxy or heterocyclic group;R1-R5 are hydrogen or an independently selected substituent, provided that R1 and R2, R2 and R3, R3 and R4 and R4 and R5 may represent fused cyclic groups;Ind is an indazole of formula (II):whereinInd is linked directly to the coupler via a ring nitrogen atom (Na or Nb); andV, W, X, Y and Z are the same or different and are hydrogen or a substituent;provided that the sum of the Hammett sigma para values of V, W, X, Y and Z is equal to or greater than 0.4.
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