Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified backing or protective layer containing
Reexamination Certificate
2000-12-19
2002-09-03
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified backing or protective layer containing
C430S206000, C430S404000, C430S537000, C430S539000, C430S628000, C430S642000, C430S963000
Reexamination Certificate
active
06444416
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a silver halide color photographic material with improved developability. In particular it relates to a silver halide color photographic element that contains a water soluble polymeric addenda.
BACKGROUND OF THE INVENTION
Silver halide photographic elements are typically exposed to suitable radiation to form a latent image. The latent image formed during exposure is amplified through a chemical development process to form a visible dye image. To form a color image, the exposed photographic elements are carried through a developer solution in which a color developing agent reduces developable silver halide to metallic silver and forms oxidized developer which in turn reacts with coupler to generate image dye. This step is generally followed by a bleaching or bleach/fixing step where the metallic silver is bleached and removed out of the gelatin binder. Finally a rinsing step is required to clean residual amounts of chemicals out of the photographic element. This photographic development process can take as long as five to fifteen minutes for a silver bromide based photographic material and as long as three to eight minutes for a silver chloride based photographic material.
In recent years, there has been great interest in accelerating the photographic process, that is, to shorten the time necessary for developing a silver halide color photographic material. A great deal of progress has been made in reformulating color photographic processing solutions and conditions including such changes as increasing developer concentration, lowering development restrainer concentration, and increasing temperature and pH. An alternative way of accelerating the photographic process, however, is to modify the photographic material itself to make it more developable. A readily developable color photographic element is desirable not only for rapid photographic processing but also for conventional photographic processing. Such a photographic element would be very robust with regard to color reproduction and density fluctuation, particularly in the higher density regions which normally take a longer time to develop.
Typically, a silver halide based photographic element consists of three imaging layers: a cyan layer, which contains a silver halide emulsion sensitized with a red responsive sensitizing dye; a magenta layer, which contains a silver halide emulsion sensitized with a green responsive sensitizing dye; and a yellow layer, which contains a silver halide emulsion sensitized with blue responsive sensitizing dye. The sensitized emulsions are dispersed in a hydrophilic gelatin matrix, which also contains color formation couplers. In the multilayer photographic elements used in color photography there are also interlayers between each imaging layer to control the random migration of oxidized developer, thereby preventing color contamination. In a color negative film or a color paper print format, the multilayer structure requires that one imaging layer of the three be located at the bottom of the pack. Thus, the bottom layer is always the last imaging layer to be developed and the most challenging to be developed.
Efforts have been made to improve the developability of the color photographic element itself. U.S. Pat. No. 5,753,422, discloses a method of improving sharpness, graininess, and push-processing by using anionic water soluble polymer addenda. U.S. Pat. No. 5,928,847, describes photographic elements with improved sensitometric properties that use ultrathin tabular grain emulsions having well balanced water swelling values in each dye-forming layer.
Despite efforts in this area, however, the need still exists for a multilayer, multicolor photographic element that has readily developable characteristics and improved sensitometric performance when processed under rapid processing conditions.
SUMMARY OF THE INVENTION
This invention provides a silver halide photographic element comprising a support and at least one gelatin containing imaging or non-imaging layer wherein during chemical processing the maximum swell of the layer is greater than the equilibrium swell. This invention further provides a silver halide photographic element comprising a support and at least one gelatin containing imaging or non-imaging layer containing a water-soluble polymeric acid.
The photographic elements of this invention have improved developability without sacrificing sensitometric performance. This is particularly advantageous in the imaging layer nearest the support which is traditionally the limiting factor in the development process.
REFERENCES:
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patent: 5066563 (1991-11-01), Aono et al.
patent: 5302501 (1994-04-01), Tamura et al.
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patent: 5928847 (1999-07-01), Visconte et al.
patent: 5958660 (1999-09-01), Taylor et al.
Kapp Daniel L.
Qiao Tiecheng A.
Twist Peter J.
Wang Yongcai
Eastman Kodak Company
Meeks Roberts Sarah
Schilling Richard L.
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