When color development processing is carried out after a silver halide photographic light-sensitive material is exposed to light, a developing agent, such as an aromatic primary amine, oxidized with silver halide reacts with a coupler to form a color image. In this process, color reproduction by a subtractive process is generally utilized. In accordance with this process, color images of yellow, magenta and cyan, which are complement colors of blue, green and red, respectively, are formed in order to reproduce images of blue, green and red.
Phenol derivatives or naphthol derivatives are mainly used as cyan color image forming couplers. However, the color images formed from conventionally employed phenol derivatives or naphthol derivatives have some problems with respect to preservability. For example, color images formed from the 2-acylaminophenol cyan couplers as described in U.S. Pat. Nos. 2,367,531, 2,369,929, 2,423,730 and 2,801,171 generally have inferior fastness to heat. Color images formed from the 2,5-diacylaminophenol cyan couplers as described in U.S. Pat. Nos. 2,772,162 and 2,895,826 generally have inferior fastness to light, and color images formed from 1-hydroxy-2-naphthamide cyan couplers generally have inferior fastness to both light and heat (particularly humidity and heat).
Further, 2-acylaminophenol cyan couplers and 1-hydroxy-2-naphthamide cyan couplers are defective in that the color density obtained therefrom severely decreases when processed with a bleaching solution having weak oxidizing power.
Cyan couplers derived from m-ethylphenols having an .alpha.-phenoxyalkyl group as a ballast group as described in U.S. Pat. No. 2,772,002 exhibit remarkably improved heat fastness of color image and extremely small reduction in color density when processed with a bleaching solution having weak oxidizing power. However, these cyan couplers have a low color forming property and have a side effect of degradating light fastness of the color image.
On the other hand, cyan couplers derived from methylphenols having an alkyl group as a ballast group as described in U.S. Pat. No. 4,686,177 have a markedly high color forming property and are excellent in light fastness of the color image formed therefrom. However, the heat fastness of the color image and the decrease in color density when processed with a bleaching solution having a weak oxidizing power are inferior, as compared with the cyan couplers as described in U.S. Pat. No. 2,772,001 mentioned above.