Ordinarily in a processing method for silver halide color photographic light-sensitive materials to obtain a color picture, the light-sensitive material is exposed image-wise to light and then, developed with color developer to form a color picture by reaction between a p-phenylenediamine series developing agent and a color-picture forming coupler. In this method subtractive color reproduction system is ordinary applied and color picture images of cyan, magenta and yellow are formed on the red-, green- and blue-sensitive layers, respectively. Recently, the high-temperature developing and the simplification of the process are progressing for the purpose to shorten the developing time in this color picture image formation. Especially, the increase of developing speed in color development is highly demanded for the shortening of developing time. Developing speed is affected by two conditions: the silver halide color light-sensitive material and the color developing agent. The composition of silver halide grains in the silver halide emulsion is an important factor in the former and the composition and condition of develop developer are important in the latter.
Hydroxylamine and sulfites are usually used as the preservatives. Especially, hydroxylamine is useful as the preservative of p-phenylene diamine type color developer. However, hydroxylamine has a disadvantage to generate ammonia by decomposition with oxidation. Generated ammonia acts on silver halide color light-sensitive materials and causes ammonia fogging. Decomposition of hydroxylamine is especially accelerated when heavy metal ion such as iron or copper exists in the color developer.
This problem can be avoided by making complex compounds of these heavy metal ions using various kinds of chelating agents. Aminopolycarboxylic acid, polyphosphoric acid and organic phosphoric acid may be usable as the chelating compounds. These chelating agents are effectively used for iron ion but are not very effective for copper ion. Moreover, recently the amount of replenishing liquor tends to decrease economize the developing process and for reducing the amount of waste water. Because of the use of reduced volume of replenishing liquor, the concentration of heavy metals accumulating in the color developer is apt to increase. A way to reduce the effect of the metal ion present in the developer is thus becoming to be important.
On the other hand, a silver halide color light-sensitive material which is mainly composed of silver chloride emulsion (hereinafter, it is called silver chloride color light-sensitive material) is very useful because it has excellent properties such as to be developed quickly and accumulation of bromide and iodide ions both of which suppress the developing reaction is prevented compared to the conventional silver halide emulsions containing silver bromide and iodide (silver-chlorobromide, -chloroiodobromide and -iodobromide emulsions). The present inventors examined this silver chloride color light-sensitive material which is favorable to the quick development and found the following shortcoming. Firstly, hydroxylamine which has been used as the preservative acts as developing agent for silver chloride and progresses the development without color formation resulting in the degradation of coloring density of the finally obtained color image.
Secondly, sulfite salt, which is another preservative, acts as the solubilising agent for silver chloride and it results in the quick progress of physical development while the balance of the silver developing reaction and the coupling reaction is retarded; namely, the silver development goes first and the coupling reaction goes late to the development, such phenomenon causes the degradation of color density.
Thirdly, fogging is easily causable when a heavy metal ion is mixed with the developer. This fogging shows a tendency to increase with the reduced replenishing amount now used in processing as a whole, especially. Furthermore, density of image also shows a tendency to be reduced. The existence of a heavy ion is important problem especially for the continuous processing of large amounts of light-sensitive material.
In case of processing by an automatic developing machine which uses a silver halide color photosensitive material for continuous processing, it is necessary to keep the concentration of the components of color developer in a prescribed range so as to avoid the change of finished properties of the light-sensitive material caused by the change of concentration of components. For this purpose, a replenisher is used so as to supplement the deficient component and to dilute the excess component concentration. With the addition of the replenisher the overflow of the solution is inevitable. This is not favorable from either an economical or pollution-preventive standpoints. So as to cope with the social demand the use of highly-concentrated replenisher to decrease the volume of the overflow as well as the recycling of developer by using electrodialysis process or ion-exchange resin are recommended. This results in a decrease of the supply of replenisher. In such cases, the accumulation of heavy metal ions are unavoidable. It is strongly required to solve the problem of heavy metal effect in the development.
Another drawback was also found. Reduction of the amount of replenisher results the increase of the concentration of color developer because of vaporization of the solution. It causes the difficulty to obtain a good stable photographic characteristics, especially, the maximum density of yellow image. In case of mini-labs, small scale photofinishing workshop, this problem is especially not negligible since discontinuous running treatment is carried out over a long time.