Radiation imagery chemistry: process – composition – or product th – Post imaging processing – Developing
Reexamination Certificate
2001-08-16
2003-03-11
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Post imaging processing
Developing
C430S350000, C430S363000, C430S448000, C430S484000, C430S486000, C430S505000, C430S566000, C430S955000, C430S958000, C430S959000
Reexamination Certificate
active
06531271
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to a color photographic element comprising a combination comprising a multifunctional coupler in association with a developer enabling cyan color, wherein the coupler has the property that it forms a distinctly colored dye with a different developer.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,756,269 to Ishikawa et al. discloses the combination of three different developers with three different couplers. For example, a coupler “Y-1” is used with a hydrazide developing agent to form a yellow dye. Ishikawa et al. does not mention, nor attach any significance to, the fact that the same coupler is a magenta dye-forming coupler if used with a common phenylenediamine developing agent.
Clarke et al., in U.S. Pat. Nos. 5,415,981 and 5,248,739, showed that azo dyes formed from a blocked hydrazide developer are shifted to shorter wavelengths. This is perhaps not surprising since azo dyes derived from “magenta couplers” are known to be typically yellow and are used as masking couplers. The substitution pattern on the masking coupler is such that it can undergo further reaction with the oxidixed form of a paraphenylene diamine developer to form a magenta dye.
R. L. Bent et al., in
Photographic Science and Engineering
, Vol. 8, No. 3, May-June 1964 disclosed that the frequencies of maximum absorption of various dyes derived from p-phenylenediamines are closely related to the half-wave oxidation potentials of the compounds. As one point on various plotted correlations experimental Compound A is disclosed (in Table II), in a 4-amino-N,N-dialkylaniline structure has 3,5-di-CH
3
substitution. The compounds are not disclosed as having any commercial utility and the reference might be construed as teaching that the use of Compound A would not be useful, since it would not provide the desired magenta hue with a conventional magenta coupler.
Japanese kokai JP 10090854 (1996) teaches different developers in the same color unit layer (having spectral sensitivity in the same wavelength range) in a photothermographic imaging element, in order to obtain better image or tone gradation.
U.S. Pat. No. 6,197,722 B1 to Irving et al. teaches a method of imaging, useful comprising providing an imaging member having at least one light insensitive layer comprising a catalytic center and multifunctional dye forming coupler, imagewise applying distinct developer solutions that will react with the multifunctional dye forming coupler to produce dyes of different colors. A preferred method of imagewise application of developer solution is by the technique known as “ink jet.”
PROBLEM TO BE SOLVED BY THE PRESENT INVENTION
Light-sensitive imaging elements which form yellow, magenta and cyan dye records of comparable density-forming ability and consistent stability in all three color records using conventional developers can be difficult. Cyan and yellow dye records can be a problem in this regard, especially in photothermographic elements. Accordingly, alternative ways of forming cyan or yellow dyes are especially useful in such imaging elements.
Another problem with conventional cyan dye-forming couplers relates to the fact that the raw stock stability of photographic elements is influenced by the physical properties of materials employed to formulate that element. Cyan dye-forming couplers are particularly prone to crystallization on extended cold keeping. This crystallization both degrades the image-forming ability of such an element and mars the appearance of images produced in such an element. This problem can be particularly acute in photothermographic or heat developable elements since it may be desirable to keep these elements cold before use, in order to prevent premature reaction.
SUMMARY OF THE INVENTION
The present invention relates to a light sensitive color photographic imaging element comprising at least two different chromogenic couplers including, in reactive association, a multifunctional coupler and a developer precursor liberating a developing agent enabling cyan color from the multifunctional coupler on development, wherein the multifunctional coupler has the property that it is capable of forming at least one other distinctly colored dye with an oxidized form of the conventional developer 4-(N-ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine. In one embodiment, the multifunctional coupler has the property that it is capable of forming a distinctly colored magenta dye with an oxidized form of the conventional developer 4-(N-ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine. The latter developer (also known as “CD2”), which developer is widely used, is used herein as a standard means for the purpose of enabling a convenient color comparison, but other developers could have been substituted instead.
In a first embodiment, the light-sensitive silver-halide color photographic element has a red-light-sensitive silver-halide layer unit and a first blocked coupling developer, a green-light-sensitive silver-halide layer unit and a second blocked coupling developer, and a blue-light-sensitive silver-halide layer unit having a third blocked coupling developer, wherein at least one layer unit, or imaging layer in the layer unit, has a multifunctional coupler.
DETAILED DESCRIPTION OF THE INVENTION
As mentioned above, the invention relates to a light-sensitive color photographic imaging element comprising at least two different chromogenic couplers including, in reactive association, a multifunctional coupler and a developer precursor that liberates a developing agent enabling cyan color from the multifunctional coupler on development, wherein the multifunctional coupler has the property that it is capable of forming at least one other distinctly colored dye with an oxidized form of the conventional developer 4-(N-ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine. The developer precursor can liberates a phenylenediamine type of developer or an aminophenol type of developer, as described in more detail below.
In one preferred embodiment, the multifunctional coupler has the property that it is capable of forming a distinctly colored magenta dye with an oxidized form of the developer 4-(N-ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine.
Thus, the invention encompasses the possible use of a number of different couplers and a number of different developing agents. There can be two different couplers or three different couplers in the imaging element. It is possible to have more than three couplers, per the Japanese kokai mentioned above. It is also possible to have more than three different developers (or blocked developers), three different developers (or blocked developers), two different developers (or blocked developers), or a single developer (or blocked developer). In one embodiment, there are two different developers and three different couplers, which may minimize costs by not having more than two developers.
Thus, an imaging element according to the present invention can, for example, comprise a red-light-sensitive layer unit, a green-light-sensitive layer unit and a blue-light-sensitive layer unit, wherein at least one layer in at least two different layer units has in reactive association an independently selected multifunctional dye forming coupler and an independently selected blocked developer, wherein the blocked developer is different in said two layer units.
Alternatively, the imaging element can comprise a red-light-sensitive layer unit, a green-light-sensitive layer unit and a blue-light-sensitive layer unit, wherein all three layer units have in reactive association an independently selected multifunctional dye forming coupler and an independently selected blocked developer, wherein the multifunctional dye coupler is different in each layer unit and the developing agent is the same in each layer units.
As a further alternative, the element can comprises a red-light-sensitive layer unit, a green-light-sensitive layer unit and a blue-light-sensitive layer unit, wherein all three layer units have in reactive association an independently sel
Irving Lyn M.
Szajewski Richard P.
Eastman Kodak Company
Konkol Chris P.
Letscher Geraldine
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