Radiation imagery chemistry: process – composition – or product th – Color imaging process – Using identified radiation sensitive composition in the...
Patent
1989-08-23
1991-10-22
Bowers, Jr., Charles L.
Radiation imagery chemistry: process, composition, or product th
Color imaging process
Using identified radiation sensitive composition in the...
430398, 430400, 430430, 430461, 430963, G03C 728
Patent
active
050595148
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method for processing silver halide color photographic light-sensitive materials having silver halide emulsion layers containing silver iodobromide and more specifically to a method for processing such photographic light-sensitive materials comprising a desilvering step in which the light-sensitive materials are rapidly bleached while reducing the amount of waste liquor derived from the bleaching treatment.
TECHNICAL BACKGROUND
In general, the basic processes for processing color light-sensitive materials are a color developing process and a desilvering process. In the color developing process, the silver halide exposed to light is reduced with a color developing agent to form elemental silver and simultaneously the oxidized color developing agent reacts with a coloring agent (coupler) to form dye images. In the subsequent desilvering process, the elemental silver formed during the color developing process is oxidized by the action of an oxidizing agent (in general, referred to as "bleaching agent") and then is dissolved by the action of a complexing agent for silver ions generally referred to as "fixing agent". Only the dye images remain on the color light-sensitive materials after the desilvering process.
The desilvering process described above generally comprises two processing baths, one of which is a bleaching bath containing a bleaching agent and the other of which is a fixing bath containing a fixing agent; or only one bath simultaneously containing a bleaching agent and a fixing agent.
The practical development processing further comprises, in addition to the foregoing basic processes, a variety of auxiliary processes for the purposes of maintaining photographic and physical properties of images, enhancing storability of images or the like. Examples of such auxiliary processes are a film hardening bath, a stopping bath, an image stabilizing bath and a water washing bath.
The bleaching agents used in the desilvering process are in general red prussiate of potash, bichromates, ferric chloride, ferric complexes of aminopolycarboxylic acids and persulfates.
However, a problem of environmental pollution arises when red prussiate of potash and bichromates are employed and the use thereof requires a specific installation for processing the same. In addition, if the ferric chloride is used, it accompanies the formation of iron hydroxide and the generation of stains during the subsequent water washing process. Thus, it is difficult to practically use such bleaching agents because of various practical obstacles mentioned above. Regarding the persulfates, the bleaching ability thereof is very weak and it takes a long period of time for bleaching. To eliminate this problem, there is proposed a method in which a bleaching accelerator is simultaneously used for enhancing the bleaching ability. However, the persulfates per se is specified as dangerous materials in accordance with the Fire Services Act. The use thereof is restricted, it is needed to take various steps in storing the same and thus practical use thereof is very difficult.
One the other hand, ferric complexes of aminopolycarboxylic acids, in particular ferric complex of ethylenediaminetetraacetic acid and ferric complex of diethylenetriaminepentaacetic acid have widely been used as a bleaching agent since they cause no environmental pollution and no problem of storage as in the case of persulfates. However, the ferric complexes of aminopolycarboxylic acids do not exhibit sufficient bleaching ability. A low sensitive silver halide color light-sensitive material mainly composed of a silver chlorobromide emulsion can be bleached with a solution containing such a ferric complex as a bleaching agent. But, if it is intended to process a highly sensitive color light-sensitive material which is mainly composed of a silver chloroiodobromide or silver iodobromide emultion and which is sensitized with a color sensitizer, in particular a photographic color reversal light-sensitive material and a photographic
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Fujita Yoshihiro
Ishikawa Takatoshi
Kitahara Tohru
Kojima Tetsuro
Ueda Shinji
Bowers Jr. Charles L.
Dote Janis L.
Fuji Photo Film Co. , Ltd.
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