Radiation imagery chemistry: process – composition – or product th – Nonradiation sensitive image processing compositions or... – Developer
Reexamination Certificate
1999-08-13
2001-04-17
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Nonradiation sensitive image processing compositions or...
Developer
C430S403000, C430S464000, C430S486000, C430S487000, C430S499000
Reexamination Certificate
active
06218093
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns a novel photographic solution for developing a silver halide photographic product, and a method of photographic processing by surface application.
BACKGROUND OF THE INVENTION
Conventionally, processing a black-and-white photographic product comprises a development step, a fixing step and a washing step. The processing of color photographic products comprises a color development step, a bleaching step, a fixing step and a washing step. These processing steps are generally implemented in processing tanks in which the photographic product is immersed.
With methods of processing in tanks, the processing solutions lose their active principles and become loaded with contaminating compounds coming from the photographic product itself or the adjacent processing solutions. The result is a reduction in efficacy of the photographic solutions, that requires the use of replenishing solutions. In particular, the developers that transform the latent image into a silver image by reducing the silver ions become loaded with halide ions coming from the photographic film. The halide ions, in a high concentration in the developing solution, greatly slow down the efficacy of the developer.
The conventional technique of processing in tanks makes it necessary to use large quantities of solution. In addition, the destruction or recycling of these large volumes of solution gives rise to many problems, in particular with respect to environmental protection. These problems are all the greater since the standards for discharging chemical solutions are becoming more and more severe.
In order to limit the problems related to the use of a large volume of solution, it appears advantageous to have a method of developing a photographic product by the surface application of a developing solution.
The technique of development by surface application of a layer of developing solution makes it possible to reduce considerably the volume of processing solution useful for the development, and consequently all the problems of recovery, recycling or destruction. However, the known methods which use this technique present drawbacks. They require for example additional processing steps that are often complex, such as for example the conditioning of the developing solution. In addition, these methods have not made it possible to obtain satisfactory sensitometric results.
SUMMARY OF THE INVENTION
One of the objects of the present invention is to provide an effective developing solution which substantially reduces the volume of solution required for developing a photographic product.
Another object of the invention is to propose a method of developing photographic products that is simple to use, and which avoids the manipulation of large volumes of solution.
The present invention concerns an aqueous developing solution comprising:
an alkanolamine in an amount greater than or equal to 0.6 mol/l,
at least one wetting agent that is stable at a high pH and miscible in the developing solution,
a quaternary ammonium salt, and
a developing agent capable of reducing the silver ions.
The present invention also concerns a photographic processing kit comprising:
a developing solution containing a silver ion developing agent, and
a second solution that contains an alkanolamine in an amount of from 0.6 to 20 mol/l, 0.1 to 20 g/l of a quaternary ammonium salt, 0.1 to 3% by volume of activator of at least one wetting agent that is stable at a high pH and miscible in the developing solution.
The present invention also concerns a method of developing an exposed photographic product that comprises the application of a layer of the developing solution of the invention to the exposed photographic product.
This method makes it possible to develop photographic products rapidly with a very small volume of developing solution. It makes it possible to process in particular high-contrast photographic products, for example photographic products for graphic art.
In addition, such a method avoids the problems of contamination or reduction in efficacy of the developing bath. This is because, in the conventional tank development methods, the same developing bath is used for processing a large number of photographic products. The chemical composition of this bath is modified over time, which gives rise to sensitometric variations in the photographic products being processed. Conventionally, this drawback is eliminated by using replenishing solutions.
In the context of the present invention, the development method eliminates the sensitometric variations due to the use of used baths. This is because the present invention makes it possible to develop photographic products with a developing solution that is never seasoned since this solution, applied in a layer to the photographic product, is used only once. This method eliminates the need to use replenishing solutions.
In addition, the application of the developing solution in a layer greatly reduces the volumes of solution required for the development of the photographic product. In this way the problems of recycling and destruction of photographic effluents are limited, as well as sensitometric variations related to the stirring of the developing baths.
This method reduces the ecological impact of the developing baths by virtue of the low volume of developing solution used. It also reduces the quantities of chemical product used.
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Eastman Kodak Company
Le Hoa Van
Tucker J. Lanny
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