A standard processing step for a silver halide color photosensitive material comprises, in general, a color developing process to form a color image, a desilvering process to remove developed or non-developed silver, and a washing process with water and/or an image stabilization process.
Hitherto, it has been attempted to reduce the processing time required for the silver halide color photosensitive material. In recent years, however, necessity of reduction in the processing time has been further increased by demands for reduction in the time limits of finish and delivery, for alleviation of laboratory work, and for miniaturization of processing system and simplification in operation of processing system for a small-scale laboratory often referred to as a miniature laboratory.
Hitherto, various penetrating agents for color developing agent have been studied in color development of silver halide color photosensitive material using an oil protect-type coupler in order to increase color development properties of the photosensitive material. In particular, a method to add benzyl alcohol to a color developing solution has been found to have a large effect on accelerating color development, and this method is now in wide use for color paper, color reversal paper, color positive film for display, and the like.
However, since benzyl alcohol has low water solubility, a solvent such as diethylene glycol, triethylene glycol, an alkanolamine, or the like is needed for its easy solubility in water. Each of these compounds including benzyl alcohol has large BOD (biological oxygen demand) and COD (chemical oxygen demand) values, which show the environmetal pollution load, so that it is desirable from the viewpoint of environmental protection to remove these compounds.
Further, since dissolution of benzyl alcohol in water takes a long time, it is better from the viewpoint of reduction in preparation work for a color developing solution to avoid use of benzyl alcohol.
In addition, when benzyl alcohol is carried over into a bleaching bath or bleach-fixing bath which is a subsequent bath, formation of a leuco dye by a cyan dye is caused and a lowering in coloring density is also caused. Further, storage properties of images of photosensitive materials after being after-treated are sometimes adversely affected by benzyl alcohol because of retardation in washing-out speed for components of the developing solution. Therefore, it is preferred also for these reasons to avoid use of benzyl alcohol.
Hitherto, it has been conventional that a color development processing takes 3 to 4 minutes, but in recent years, a reduction in processing time for color development has been demanded with the aim of reduction of the time limit of finish and delivery and of reduction of laboratory work.
However, if benzyl alcohol, which is a color development accelerator, is removed and if the development time is also reduced, a marked lowering in coloring density is inevitably caused.
To solve this problem, various color development accelerators (such as compounds as mentioned, for example, in U.S. Pat. Nos. 2,950,970, 2,515,147, 2,496,903, 2,304,925, 4,038,075, and 4,119,462; British Pat. Nos. 1,430,998 and 1,455,413; Japanese patent application (OPI) Nos. 15831/78, 624050/80, 62451/80, 62452/80, and 62453/80 the term "OPI" as used herein means "unexamined published patent application"); and Japanese Patent Publication Nos. 12422/76 and 49728/80 have been used in combination, but fully sufficient coloring density has not been obtained.
If a method using a photographic material containing 3-pyrazolidones (for example, methods as mentioned in Japanese patent application (OPI) Nos. 26338/85, 158444/85, and 158446/85) is used, it has a defect that the sensitivity is lowered with a lapse of time, or fogs are formed.
Further, if a method using a photographic material containing a color developing agent (for example, methods as mentioned in U.S. Pat. Nos. 3,719,492, 3,342,559, and 3,342,597 and Japanese patent application (OPI) Nos. 6235/81, 16133/81, 97531/82, and 83565/82) is used, it has defects such as retarded color development, formation of fogs, and the like, so that it is not an appropriate method.
All the above-mentioned methods have insufficient color development properties when substantially no benzyl alcohol is contained in the color developing solution. Also, none of such methods can provide stable photographic characteristics in a continuous processing or in the case that the development time is reduced.