For silver halide color photographic materials (hereinafter simply referred to as light-sensitive materials), particularly those for photographing, it is required to have high sensitivity, to not exhibit fluctuation of photographic performance during preservation of the light-sensitive materials, and to have excellent image quality (color reproducibility, sharpness and granularity) and preservability of the color images formed.
As yellow couplers for forming color photographic images in the subtractive color process, acyl acetamide couplers typically include benzoyl acetanilides and pivaloyl acetanilides. The former couplers are mainly utilized in color light-sensitive materials for photographing which require a high sensitivity, since they ordinarily have a high coupling activity with an oxidation product of an aromatic primary amine developing agent in color development, and since the molecular extinction coefficient of yellow dyes formed therefrom is large in comparison with that of yellow dyes formed from the latter couplers. On the other hand, the latter yellow couplers are mainly utilized in color papers or in color reversal photographic materials, because they are superior to the former couplers in view of their spectral absorption characteristics and the fastness of the yellow dyes formed therefrom.
As described above, although benzoyl acetanilide type couplers have a high coupling reactivity with an oxidation product of an aromatic primary amine developing agent in color development, and a somewhat large molecular extinction coefficient of yellow dyes formed therefrom as compared with pivaloyl acetanilide couplers, they have problems in that the spectral absorption characteristics and the fastness of the yellow color images formed therefrom are poor. When the couplers have a high coupling reactivity and a large molecular extinction coefficient of the dyes formed therefrom, it becomes possible to provide high sensitivity, gradation and color density, and to bring about a so-called high color forming property. The excellent spectral absorption characteristics of the yellow color image results, for example, in a low absorption density on the longer wavelength side of the absorption spectrum, and in small undesirable absorption in the green region.
Therefore, it has been desirable to develop a yellow coupler which provides not only a high color density due to a high molecular extinction coefficient of the dye formed, but also a color image having excellent spectral absorption characteristics and fastness.
Acyl groups of the acyl acetanilide couplers, include a pivaloyl group, a 7,7-dimethylnorbornane-1-carbonyl group and an 1-methylcyclohexane-1-carbonyl group as described in U.S. Pat. No. 3,265,506, and a cyclopropane-1-carbonyl group and a cyclohexane-1-carbonyl group as described in JP-A-47-26133 (the term "JP-A" as used herein means an unexamined published Japanese patent application). However, these couplers are disadvantageous in that they have poor coupling reactivity, the molecular extinction coefficient of dyes formed therefrom are low, the spectral absorption characteristics of the color image formed are poor, or the fastness of color image formed is poor.
Further, benzoyl acetanilide or pivaloyl acetanilide couplers having an oil-soluble diffusion resistant group in their molecules, which are representative examples of acyl acetanilide couplers, have the problem that the above-described color forming property is degraded when the amount of a high-boiling point organic solvent added per unit weight of the coupler is small in a process for the production of a color light-sensitive material in which the coupler is mixed with a high-boiling point organic solvent, dissolved therein, and then finely dispersed to prepare a dispersion, and the resulting coupler dispersion is mixed with a silver halide emulsion.
On the other hand, malondiamide couplers which are relevant to one of the yellow couplers according to the present invention are described in French Patent 1,558,452. However, the couplers described therein are so-called O-releasing type couplers which have a group capable of being released through an oxygen atom at their active position and are predominantly diffusible couplers. Also, as functional couplers of malondiamide couplers, development inhibitor releasing (DIR) couplers are described, for example, in JP-A-52-69624, JP-A-52-82424, JP-A-57-151944 and JP-A-2-250053. However specific examples of the compounds are not described in JP-A-52-82424 and JP-A-57-151944, and the effect is not specifically described in JP-A-52-69624. Further, it has been found that the couplers described in the above described patents have some problems with respect to color forming preservability of the light-sensitive materials containing them, and color image fastness.
USPTO Backgrounds
USPTO Backgrounds