Radiation imagery chemistry: process – composition – or product th – Post imaging processing – With structural limitation
Reexamination Certificate
2003-02-14
2004-02-17
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Post imaging processing
With structural limitation
C396S625000
Reexamination Certificate
active
06692904
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a wash solution for the rapid processing of silver halide photographic materials and to a process in which it is used.
BACKGROUND OF THE INVENTION
After an exposed photographic material has been subjected to the stages of development, bleaching and fixing it is usually also subjected to a washing stage to remove chemicals that affect the image quality from the photographic layer. Previously this washing stage has been carried out by contacting the photographic material with flowing water for sufficient time to allow the chemicals that affect image quality to diffuse through the photographic layer and into the wash solution. These chemicals may come from the previous processing baths or may come from the original photographic material. The chemicals that might emanate from previous processing baths include sulphite and thiosulphate and those from the original material would include silver compounds, the sensitizing dyes that were used to modify the spectral response of the silver compounds and also other coloured dyes added to the photographic layers to modify spectral response and increase image sharpness.
PROBLEM TO BE SOLVED BY THE INVENTION
There is a continuing need to reduce the overall processing time and it is therefore desirable to reduce the duration of any or all of the individual stages of development, bleaching, fixing and washing. Previously the duration of the washing stage could not be reduced without the risk of incomplete removal of the contaminants mentioned above and consequent loss of image quality. The problem is to provide a washing process which will remove these contaminants and be sufficiently fast so that the washing time and hence the overall process time comprising development, bleaching, fixing and washing is reduced. The present invention provides a solution to this problem by employing an oxidizing agent in the wash solution.
SUMMARY OF THE INVENTION
According to the present invention there is provided a photographic washing bath comprising a chamber containing a wash solution for a silver halide photographic material said wash solution having a pH of less than 7 and comprising water having dissolved therein an oxidizing agent having an oxidation potential of at least 1 volt and being in a concentration of from 0.05 to 2 moles per liter.
According to another aspect of the present invention there is provided a photographic washing process which process comprises washing a silver halide photographic material which has been subjected to development, bleaching and fixing, said washing being with an aqueous wash solution as hereinbefore defined.
ADVANTAGEOUS EFFECT OF THE INVENTION
The use of an oxidizing agent in the wash solution enables the duration of the washing stage to be reduced and thereby reduce the duration of the overall process of development, bleaching, fixing and washing.
REFERENCES:
patent: 5528329 (1996-06-01), Sawada et al.
patent: 5910397 (1999-06-01), Feumi-Jantou et al.
patent: 6505979 (2003-01-01), Twist et al.
patent: 0 602 446 (1994-06-01), None
patent: 0 872 762 (1998-10-01), None
patent: 0 872 763 (1998-10-01), None
patent: 0 939 337 (1999-09-01), None
patent: 1 111 457 (2001-06-01), None
JP Abstract 11242312.
JP Abstract 63044654.
JP Abstract 2000292891.
Fyson John R.
Hall Jeffrey L.
Twist Peter J.
Eastman Kodak Company
Le Hoa Van
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