Radiation imagery chemistry: process – composition – or product th – Nonradiation sensitive image processing compositions or... – Developer
Reexamination Certificate
1995-09-28
2001-02-20
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Nonradiation sensitive image processing compositions or...
Developer
C430S490000
Reexamination Certificate
active
06190845
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to compositions of color developing agent and color developer compositions for processing silver halide color photographic material and a method of using the same. More specifically, the invention relates to compositions of aqueous solution of color developing agent having excellent stability in use and color developer compositions used in highly concentrated solution for color development processing wherein the compositions are capable of preventing precipitation of the color developer agent.
PRIOR ART
Among the basic process of color photographic material that are effected after exposure of the photographic material to a light image, are those of color developing, silver bleaching, silver halide fixing, bleaching fixing, in which a bleaching process and a fixing process are effected at a time, water washing, rinsing which is effected in lieu of the water washing process, stabilizing and drying. In addition, there are additional processes, which are executed to permit each process to be used stably or to increase the physical strength and stability of the processed photographic material. Among methods of processing silver halide color photographic materials are those of processing color negative films to obtain color prints, which are the methods most widely used today, and those for directly obtaining final images in the form of positive color films or prints. Further, users of color prints want to see the prints as soon as possible and desire the production of prints in as short a period of time as possible. To meet this demand, it is necessary to provide quick processing.
In recent years, it is possible to quickly process silver halide color photographic materials owing to improvements therein. In addition, easy processing of a large quantity of materials is possible with automatic developing apparatus. Further, the automatic developing apparatus has been improved, and a variety of compact and inexpensive apparatuses are used. An automatic developing apparatus is normally used for carrying out the above photographic process. In actual processing of a large quantity of photographic materials, the process of a given quantity of photographic material is carried out while replenishing with a necessary quantity of process solution as replenishment solution. A photographic material processor who accepts a request to process photographic material from a photographer has to effect the desired process in a short period of time.
In order to process a silver halide color photographic material easily and quickly, agents necessary for the processing are available on the market in the form of a liquid so that they can be used by simply diluting with water. Desired of these agents are easy usage and capability of being used without producing detriment to the surronding environment. These agents are supplied in various conditions, some of which are not suitable for use in a satisfactory environmental condition. In actual practice, a color develop for processing a silver halide color photographic material is supplied separately in three to four parts. The reason for this separation into a plurality of parts is to prevent the quality of the developer from deteriorating even in cases where there may be a long interval between the time the developer was produced and actually used and also to ensure that composition of each part of solution is such that it does not present any problem when mixed with other solutions. Of those various solutions, color developing agent is oxidized by silver halide exposed to light and then, reacting with coupler contained in the silver halide color photographic material, generates a pigment image. The developing agent used is of a paraphenylene diamine type, which, when as a liquid, has to be in the form of a concentrated aqueous solution and also has to be stable even when subjected to various storage conditions. As a paraphenylene diamine type color developing agent tends to be oxidized in storage, it is normally prepared as concentrated aqueous solution with sulfurous compound being added to prevent oxidation of the agent. Examples of methods for improving stability of compositions of color developing agents supplied in the form of aqueous solution are shown in Japanese Patent Publication No. 37957/1970, like Publication No. 24050/1973, Japanese Patent Application Public Disclosure No. 136045/1988, like Disclosure No. 181245/1993 and U.S. Pat. Nos. 3,615,572, 3,647,461 and 3,647,462. All of the aforementioned, however, call for using sulfurous compounds and therefore present a problem in that sulfur dioxide is generated.
There are trends towards reducing the time and the quantity of solutions required for processing silver halide color photographic material. Reducing the time required for processing is advantageous in improving the efficiency of photographic processing and also in making automatic developing apparatuses compact. Reducing the size of an automatic developing apparatus results in reduction of the quantity of solutions used for processing, which means that the quantity of waste liquid is reduced. In conducting the photographic processing, for which an automatic developing apparatus is normally used, the process of a given quantity of photographic material is carried out while feeding solutions necessary for processing into the automatic developing apparatus as replenishment solutions, the quantity of each replenishment solution being in proportion to the quantity of the photographic material to be processed, and used solutions are overflowed from the apparatus and discharged. The discharged waste liquid is collected for batch disposal. As automatic developing apparatus have been made compact, they can be now installed anywhere their users wish, and, as a result, they are sometimes installed where it is difficult to provide plumbing for disposal of overflow waste liquid. This is why waste liquid has to be collected as described above. With regard to environmental pollution, the overflow liquid cannot be disposed of directly but has to be collected and treated before being discharged into the environment. Regarding collection of overflow waste liquid, naturally, the less the quantity of waste liquid, the better in view of the cost and frequency required for the collection. Therefore, various methods for reducing overflow liquid have recently been provided and put into actual practice. Examples of these methods include those utilizing ion exchange resin, color developer revitalizing methods utilizing electrodialysis, revitalization of color developer simply by using a regenerant, and low-volume replenishing processing methods involving increase of concentration of components of replenishement solutions. Revitalization of color developer is comprised of removal of insoluble sediment and replenishment of insufficient components, or, simply, of replenishment of insufficient components. Although color developer solutions can be revitalized by the above methods, a special device, space and/or procedures, such as, analysis of components of developing solutions in order to stabilize the quality of photographs, are necessary to implement these methods. In this regard, revitalization presents many problems including time and operational complications involved with its execution. On the other hand, methods calling for using only a small quantity of highly concentrated replenishment solutions are probably most appropriate, because they require neither a special device nor procedures. However, they present another problem in that, when preparing color developer solution, color developing agent having a low solubility under a high pH precipitates in the form of a crystal at a low temperature. As crystals thus precipitated are hard to dissolve, they tend to cause serious problems including abnormality in composition of color developer, clogging up of the circulation system of an automatic developing apparatus and damages to photographic material by the precipitate. Examples of methods for solving this problem include
Chugai Phote Chemical Co., LTD
Le Hoa Van
Oldham & Oldham Co. LPA
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