Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
2002-07-18
2004-05-18
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
active
06737229
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to improved photographic elements for producing reversal images. More specifically, this invention relates to reversal silver halide photographic elements containing an imaging layer comprising an imaging emulsion and a non-image forming emulsion having an equal or higher iodide concentration than the imaging emulsion.
BACKGROUND OF THE INVENTION
The term “reversal photographic element” designates a photographic element which produces a photographic image for viewing by being imagewise exposed and developed with a first non-chromogenic “black and white” developing agent to produce a negative of the image to be viewed, followed by uniform exposure and/or fogging of residual silver halide and processing to produce a second, viewable image. Such reversal elements are typically sold packaged with instructions to process using a color reversal process such as the Kodak E-6 process as described in The British Journal of Photography Annual of 1988, page 194. Color slides, such as those produced from Kodachrome® and Ektachrome® films, constitute a popular example of reversal photographic elements. In the overwhelming majority of applications the first image is negative and the second image is positive. Reversal photographic elements frequently comprise silver haloiodide imaging emulsions, where the term “silver haloiodide” is employed in its art recognized usage to designate silver halide grains containing silver ions in combination with iodide ions and at least one of chloride and bromide ions.
Groet U.S. Pat. No. 4,082,553 illustrates a conventional reversal photographic element containing a silver haloiodide grain emulsion modified by the incorporation of a small proportion of fogged silver halide grains. Hayashi et al German OLS No. 3,402,840 is similar to Groet, but describes the imaging silver halide grains in terms of those larger than and smaller than 0.3 micrometer and additionally requires in addition to the fogged silver halide grains or their metal or metal sulfide equivalent an organic compound capable of forming a silver salt of low solubility.
Tabular grain silver haloiodide emulsions have been recognized to provide a variety of photographic advantages, such as improvements in speed-granularity relationships, increased image sharpness, and reduced blue speed of minus blue recording emulsion layers. Tabular grain silver haloiodide emulsions in reversal photographic elements are illustrated by Research Disclosure Vol. 225, January 1983, Item 22534; Wilgus et al U.S. Pat. No. 4,434,226; Kofron et al U.S. Pat. No. 4,439,520; Solberg et al U.S. Pat. No. 4,433,048; Maskasky U.S. Pat. No. 4,400,463; and Maskasky U.S. Pat. No. 4,435,501. Research Disclosure is published by Kenneth Mason Publications, Ltd., The Old Harbourmaster's, 8 North Street, Emsworth, Hampshire P010 7DD, England.
U.S. Pat. No. 4,656,122 describes silver halide photographic elements capable of producing reversal images including one emulsion layer comprising a blend of tabular silver haloiodide grains and fine grains of a silver salt more soluble than silver iodide, which more soluble fine grains contain less iodide than the tabular grains. The addition of relatively fine grains consisting essentially of a silver salt more soluble than silver iodide to an image forming layer containing tabular silver haloiodide grains may produce a combination of advantages in reversal imaging. The reversal threshold speed of the reversal photographic elements can be increased. At the same time, reduced toe region density in the reversal image as well as increases in maximum density and contrast are observed. In U.S. Pat. No. 5,391,468, the addition of dye to high solubility fine grains which are added to an imaging emulsion layer such as taught in U.S. Pat. No. 4,656,122 to further improve speed and contrast is described. In U.S. Pat. No. 5,176,990, the dual melting of a fine grain emulsion such as taught in U.S. Pat. No. 4,656,122 with an imaging emulsion is described.
Blending of two or more imaging emulsions in image recording layer of photographic elements to obtain various desired photographic features is also well known. Blending of emulsions in color reversal photographic elements, e.g., is described in U.S. Pat. Nos. 5,876,914, 5,567,579, 4,554,245, EP 0 763 773, and JP01-166039A2.
Imaging dyes used in photographic materials generally have unwanted light absorption which reduce color saturation and may cause loss of color accuracy. Techniques for generating interimage effect (IE) upon photographic processing are known which will compensate such unwanted light absorption to a certain extent. A recent trend in photographic materials has led to the desire for increased color saturation in various applications. Therefore, techniques for providing more interimage effect are desirable.
U.S. Pat. Nos. 5,932,401 and 6,162,595 disclose reversal photographic element film structures which enhance interimage effect by combining a light sensitive imaging emulsion and a relatively large amount of one or more non-image forming fine grain emulsions in a substantially non-image forming special layer of the element. The use of very fine grain non-image forming emulsions (e.g., preferably less than 0.07 micrometer grain size) is taught as being preferred in the special layer in U.S. Pat. No. 5,932,401 to provide a relatively large surface area ratio relative to the imaging emulsion grain surface area to enhance interimage effects. Examples include the use of non-image forming emulsions which do and which do not include iodide. The use of a second larger non-image forming silver halide emulsion comprising iodide in combination with a smaller non-image forming emulsion in the special substantially non-image forming layer, or the use of a very polydisperse non-image forming silver halide emulsion comprising iodide in the special layer, is taught in U.S. Pat. No. 6,162,595 as being useful for further enhancing interimage effect in low density regions of a processed reversal element, relative to the effect achieved with a single non-image forming emulsion which is not very polydisperse at equal silver laydown.
While interimage effects may be increased for reversal elements when employing a special layer in accordance with U.S. Pat. Nos. 5,932,401 and 6,162,595, the requirement for an additional layer or layers adds to the complexity and cost of the photographic element. Additionally, it may be difficult to control the relative degree of color correction between various color records depending upon location of the special layer. Accordingly, it would be desirable to be able to increase interimage effects, especially in a relatively controllable manner, without the need for a separate special substantially non-forming layer.
SUMMARY OF THE INVENTION
In accordance with the invention, a reversal photographic element is disclosed comprising a support and, coated on said support, at least one image recording emulsion layer comprised of: a) a light sensitive silver halide imaging emulsion; and b) a non-image forming silver halide emulsion having an average grain size less than 0.3 &mgr;m and which comprises at least 13 percent of the total silver in the image recording layer, wherein the non-image forming silver halide emulsion comprises at least 1 mole percent iodide, and the iodide mole percentage of the non-image forming silver halide emulsion is equal to or higher than that of the imaging emulsion.
In preferred embodiments, the elements of the invention are multicolor photographic elements capable of forming a variable reversal dye image, and comprise a blue recording yellow dye image forming layer unit; a green recording magenta dye image forming layer unit, and a red recording cyan dye image forming layer unit. The combination of the imaging and non-image forming emulsions in at least one image forming layer of a reversal photographic element gives an increase in interlayer interimage effects, increasing the color of the element upon reversal photographic processing. In accordance with a
Chen Keath T.
Dannhauser Thomas J.
Anderson Andrew J.
Eastman Kodak Company
Le Hoa Van
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