Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Identified radiation sensitive composition with color...
Reexamination Certificate
2002-10-24
2004-01-20
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Identified radiation sensitive composition with color...
C430S552000, C430S553000, C430S384000, C430S385000
Reexamination Certificate
active
06680165
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to silver halide photographic materials and methods of making such materials, and more specifically to photographic materials comprising dispersions of specific phenolic dye-forming photographic coupler combinations with limited amounts of phenolic activators.
BACKGROUND OF THE INVENTION
Color photographic recording materials generally contain silver halide emulsion layers sensitized to each of the blue, green and red regions of the visible spectrum, with each layer having associated therewith a color forming compound called a coupler. After exposure to light and being subjected to color development with a so-called color developer, the coupling reaction between the oxidation product of an aromatic primary amine and the coupler results in the formation of colored dyes. The blue, green and red sensitive layers yielding respectively, a yellow, magenta and cyan dye.
The coupling speed (hereinafter referred to as coupler activity) in the reaction is preferably desired to be as high as possible so as to obtain higher color density within the limited development time. Higher activity and higher color density are desired to minimize the amount of coupler that is necessary to be coated to obtain this higher color density.
Further, the quality of the resulting dye image is primarily based on the dye hues obtained from the respective color forming coupler compounds. A problem associated with such couplers is that the spectral absorption characteristics of dyes obtained therefrom may not be in the particular narrow wavelength range where absorption is most desired and therefore the coupler may be rejected for commercial use.
As cyan forming couplers capable of satisfying these characteristics for color negative films, phenols have popularly been used, including 2-acylamino-5-alkyl substituted, 2,5-diacylamino substituted, and 2-ureido-5-acylamino substituted phenols. However, the dyes of 2-acylamino substituted phenolic cyan couplers that have an alkyl group with 1 or more carbon atoms in the 5-position typically have an absorption maximum too hypsochromic to be useful for color negative films. The dyes of most 2,5 diacylamino based phenols are also too hypsochromic. While some phenolic couplers which incorporate 2-ureido-5-acylamino functionality are known to advantageously yield high activity, high color density, and suitable dye hue for color negative films, such advantageous couplers are often expensive to manufacture.
Attempts to alter phenolic coupler activities and the absorption characteristics of their respective dyes are usually focused on alterations of the structures of the coupler compounds. This approach, while enjoying some measure of success, is not only time consuming, but also involves the expense of highly focused research programs. Success with such programs is not predictable so that improvements in final coupler activity and final hue values have been elusive, even after concentrated research efforts.
Attempts to shift dye hues of phenolic couplers with addenda and coupler solvents are known (U.S. Pat. No. 5,019,493, U.S. Pat. No. 6,200,741 B1; U.S. Pat. No. 3,676,137; U.S. Pat. No. 4,973,535). The use of accelerators for increasing coupler activity has also been discussed (U.S. Pat. No. 4,774,166) but their use has been mostly associated with the elimination of benzyl alcohol from a color photographic paper processing, not color negative film. The use of non-color developable phenolic compounds as addenda or as organic solvent for 2-ureido-5-acylamino phenolic coupler dispersions has been suggested (U.S. Pat. No. 4,551,422). Such compounds, however, can shift the dye hue lambda max for such couplers to excessively long values for color negative film applications.
It would be desirable to have a cyan coupler dispersion formulation in a color negative photographic element that yields cyan dye of high activity and high density and of the appropriate dye absorption maximum while at the same time allowing for the reduction of expensive 2-ureido-5-acylamino color negative couplers.
SUMMARY OF THE INVENTION
The invention provides a color negative photographic element comprising a light sensitive silver halide emulsion imaging layer having associated therewith a cyan dye-forming coupler dispersion comprising a first phenolic cyan dye-forming coupler, a second phenolic cyan dye-forming coupler, a substantially non-color-developable phenolic activator compound, and a non-phenolic organic coupler solvent having a boiling point of at least 150C; wherein
the first phenolic cyan dye-forming coupler is represented by the Formula [P]:
where
R
1
represents a ballast group,
n is from 0 to 3 and each EW represents independent electron withdrawing groups, and
X represents a hydrogen atom or a coupling off group;
the second phenolic cyan dye-forming coupler is represented by [AP] and comprises at least one of Formula [AP-I] or Formula [AP-II]:
where
R
2
represents a ballast group,
R
3
represents an alkyl group,
R
4
represents a hydrogen or halogen atom or an alkyl or an acylamino group, and
Y represents a hydrogen atom or a coupling off group;
where
where R
5
and R
6
each represents an aliphatic group, an aryl group or a heterocyclic group, and
Z represents a hydrogen atom or a group capable of being released upon a coupling reaction with the oxidation product of a developing agent;
the substantially non-color-developable phenolic activator compound is represented by the Formula [ACT]:
where
q is from 1 to 3, and each R
7
independently represents an aliphatic group, a cycloalkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a sulfamoyl group, a sulfonamido group, a sulfonyl group, an aryl group, an alkoxy group, or a halogen atom; and
wherein compounds represented by [P], [AP], and [ACT] are present in the coupler dispersion in relative weight fractions of from 0.30 to 0.65 for [P], from 0.15 to 0.35 for [AP], and from 0.15 to 0.35 for [ACT], provided the sum of the relative weight fractions for [P]+[AP]+[ACT]=1, and the weight ratio of the non-phenolic coupler solvent in the coupler dispersion is from 0.30 to 2.0 relative to the sum of [P]+[AP]+[ACT].
Photographic elements incorporating the dispersion formulation of this invention provide good activity, a cyan dye of high density and acceptable absorption maximum for color negative films. In addition, partial substitution of less expensive cyan auxiliary phenolic coupler [AP] and activator [ACT] for cyan phenolic coupler [P] advantageously allows cost savings.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, 2-ureido-5-acylamino substituted phenolic cyan dye-forming couplers are used in combination with generally less expensive phenolic couplers where the 2-substituent is other than an ureido group, along with a substantially non-color-developable phenolic activator compound and a non-phenolic high boiling organic coupler solvent. 2-ureido-5-acylamino substituted phenolic cyan dye-forming couplers which may be employed in accordance with the invention may be represented by the Formula [P]:
where R
1
represents a ballast group, n is from 0 to 3 and each EW represents independent electron withdrawing groups, and X represents a hydrogen atom or a coupling off group.
Electron withdrawing group substituents EW include groups having a Hammett's sigma para value greater than 0. Hammett's sigma values may be obtained from “Substituent constants for Correlation Analysis in Chemistry and Biology” by Hansch and Leo, available from Wiley and Sons, New York, N.Y. (1979). For example the aryl ring may be substituted with a cyano, chloro, fluoro, bromo, iodo, alkyl- or aryl-carbonyl, alkyl- or aryloxycarbonyl, acyloxy, carbona
Merkel Paul B.
Michno Drake M.
Poslusny Jerrold N.
Ross David S.
Rothrock Richard K.
Anderson Andrew J.
Eastman Kodak Company
Letscher Geraldine
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