Cyan coupler, and stabilizer-containing photographic element and process

Disclosed is a photographic element comprising at least one light sensitive silver halide emulsion layer having associated therewith: (A) a phenolic cyan dye-forming "NB coupler"; PA1 (B) a high boiling solvent having Formula (II): EQU R.sup.3 OO--C--(--G--)--C--OO--R.sup.4 (II) PA1 wherein: PA2 R.sup.3 and R.sup.4 represent independently selected alkyl or aryl groups; and PA2 G represents an alkyl (including cycloalkyl and aralkyl) containing linking group; and PA1 (C) a stabilizer having Formula (III): ##STR1## wherein each Y is an independently selected substituent and m is 0 to 4; and PA2 each T is an independently selected substituent and p is 0 to 4.

FIELD OF THE INVENTION 
The present invention relates to a color photographic element containing a 
particular type of phenolic cyan coupler in combination with a described 
solvent and stabilizer. 
BACKGROUND OF THE INVENTION 
In silver halide based color photography, a typical photographic element 
contains multiple layers of light-sensitive photographic silver halide 
emulsions coated on a support with one or more of these layers being 
spectrally sensitized to each of blue light, green light and red light. 
The blue, green, and red light-sensitive layers typically contain yellow, 
magenta, and cyan dye-forming couplers, respectively. After exposure to 
light, color development is accomplished by immersing the exposed material 
in an aqueous alkali solution containing an aromatic primary amine 
color-developing agent. The dye-forming couplers are selected so as to 
react with the oxidized color developing agent to provide yellow, magenta 
and cyan dyes in the so called subtractive color process to reproduce 
their complementary colors, blue, green and red as in the original image. 
The important features for selecting the dye-forming coupler include, 
efficient reaction with oxidized color developing agent, thus minimizing 
the necessary amounts of coupler and silver halide in the photographic 
element; the formation of dyes with hues appropriate for the photographic 
use of interest, for color photographic paper applications this requires 
that dyes have low unwanted side absorption leading to good color 
reproduction in the photographic print; minimization of image dye loss 
contributing to improved image permanence under both ambient illumination 
and conventional storage conditions; and in addition the selected 
dye-forming coupler must exhibit good solubility in coupler solvents, 
provide good dispersibility in gelatin and remain stable during handling 
and manipulation for maximum efficiency in manufacturing processes. 
In recent years, a great deal of study has been conducted to improve 
dye-forming couplers for silver halide photosensitive materials in terms 
of improved color reproducibility and image dye stability. However, 
further improvements are needed, particularly in the area of cyan 
couplers. In general, cyan dyes are formed from naphthols and phenols as 
described, for example, in U.S. Pat. Nos. 2,367,351, 2,423,730, 2,474,293, 
2,772,161, 2,772,162, 2,895,826, 2,920,961, 3,002,836, 3,466,622, 
3,476,563, 3,552,962, 3,758,308, 3,779,763, 3,839,044, 3,880,661, 
3,998,642, 4,333,999, 4,990,436, 4,960,685, and 5,476,757; in French 
patents 1,478,188 and 1,479,043; and in British patent 2,070,000. These 
types of couplers can be used either by being incorporated in the 
photographic silver halide emulsion layers or externally in the processing 
baths. In the former case the couplers must have ballast substituents 
built into the molecule to prevent the couplers from migrating from one 
layer into another. Although these couplers have been used extensively in 
color photographic film and paper products, the dyes derived from them 
still suffer from poor stability to heat, humidity or light, low coupling 
efficiency or optical density, and in particular from undesirable blue and 
green absorptions which cause considerable reduction in color reproduction 
and color saturation. 
Cyan couplers which have been recently proposed to overcome some of these 
problems are 2,5-diacylaminophenols containing a sulfone, sulfonamido or 
sulfate moiety in the ballasts at the 5-position, as disclosed in U.S. 
Pat. Nos. 4,609,619, 4,775,616, 4,849,328, 5,008,180, 5,045,442, and 
5,183,729; and Japanese patent applications JP02035450 A2, JP01253742 A2, 
JP04163448 A2, JP04212152 A2, and JP05204110 A2. Even though cyan image 
dyes formed from these couplers show improved stability to heat and 
humidity, enhanced optical density and resistance to reduction by ferrous 
ions in the bleach bath, the dye absorption maxima (.lambda.max) are too 
bathochromically shifted (that is, shifted to the red end of the visible 
spectrum) and the absorption spectra are too broad with considerable 
amounts of undesirable blue and green absorptions. Thus, these couplers 
are not practical for use in color papers. 
The hue of a dye is a function of both the shape and the position of its 
spectral absorption band. Traditionally, the cyan dyes used in color 
photographic papers have had nearly symmetrical absorption bands centered 
in the region of 620 to 680 nm, preferably 630 to 660 nm, and more 
preferably 635 to 655 nm. Such dyes have rather large amounts of unwanted 
absorption in the green and blue regions of the spectrum. 
More desirable would be a dye whose absorption band is asymmetrical in 
nature and biased towards the green region, that is, with a steep slope on 
the short wavelength side. Such a dye would suitably peak at a shorter 
wavelength than a dye with symmetrical absorption band, but the exact 
position of the desired peak depends on several factors including the 
degree of asymmetry and the shapes and positions of the absorption bands 
of the magenta and yellow dyes with which it is associated. 
Recently, Lau et. al., in U.S. Pat. No. 5,686,235 describe a particular 
class of cyan dye-forming coupler that has been shown to improve thermal 
stability and hue, particularly, with decreased absorption in side bands 
and an absorption band that is asymmetrical in nature. However, it has 
been found that dispersions of these couplers are difficult to prepare 
free of crystalline material, and are not stable with time in cold 
storage. Other related patents are U.S. Pat. Nos. 5,047,314, 5,047,315, 
5,057,408, and 5,162,197. 
Large-scale manufacturing of photographic materials can be severely 
hindered when crystalline material is present in dispersions and coating 
melts of such dispersions. This can lead to difficulty in manufacturing by 
plugging filters and causing defects in coatings of photographic 
materials. It is therefore desirable to use dispersions which have few, if 
any, crystals and are stable in cold storage from the time of preparation 
until the time of use. 
The problem to be solved is to provide an element containing a dispersion 
of the coupler useful in this invention, which dispersion has a low number 
of crystals, is stable toward crystal formation during manufacturing, and 
which provides high reactivity for formation dye with oxidized color 
developing agent. 
SUMMARY OF THE INVENTION 
The invention provides a photographic element comprising at least one light 
sensitive silver halide emulsion layer having associated therewith: 
(A) a phenolic cyan dye-forming "NB coupler"; 
(B) a high boiling solvent having Formula (II): 
EQU R.sup.3 OO--C--(--G--)--C--OO--R.sup.4 (II) 
wherein: 
R.sup.3 and R.sup.4 represent independently selected alkyl or aryl groups; 
and 
G represents an alkyl (including cycloalkyl and aralkyl) containing linking 
group; and 
a stabilizer having Formula (III): 
##STR2## 
wherein each Y is an independently selected substituent and m is 0 to 4; 
and 
each T is an independently selected substituent and p is 0 to 4. 
The invention provides an element containing a dispersion of the coupler 
useful in this invention, which dispersion has a low number of crystals, 
is stable toward crystal formation during manufacturing, and which 
provides high reactivity for formation dye with oxidized color developing 
agent.

DETAILED DESCRIPTION OF THE INVENTION 
The invention relates to a photographic element containing a cyan 
dye-forming coupler which upon processing in the conventional manner forms 
in the exposed areas, a cyan dye whose absorption spectrum is 
hypsochromically shifted (that is, shifted toward the blue end of the 
spectrum) and sharp-cutting on its short wavelength side. The former is 
particularly necessary for prints obtained in accordance with conventional 
printing processes, and the latter improves color reproduction and 
provides high color saturation. In accordance with the invention, these 
cyan couplers are advantageously combined with certain solvents and 
stabilizers which enable minimization of the amounts of coupler and silver 
necessary to achieve good photographic images, low unwanted side-band 
absorption particularly on the hypsochromic side of the absorption band, 
improved light stability which can be adjusted to achieve neutral fade 
with respect to the magenta and yellow dyes, good thermal stability for 
album keeping, as well as ease in manufacturing defect free coatings 
because coating filters are not clogged by crystalline materials in the 
dispersion. 
For purposes of this invention, an "NB coupler" is a dye-forming coupler 
which is capable of coupling with the developer 
4-amino-3-methyl-N-ethyl-N-(2-methanesulfonamidoethyl) aniline 
sesquisulfate hydrate to form a dye for which the left bandwidth (LBW) of 
its absorption spectra upon "spin coating" of a 3% w/v solution of the dye 
in di-n-butyl sebacate solvent is at least 5 nm. less than the LBW for a 
3% w/v solution of the same dye in acetonitrile. The LBW of the spectral 
curve for a dye is the distance between the left side of the spectral 
curve and the wavelength of maximum absorption measured at a density of 
half the maximum. 
The "spin coating" sample is prepared by first preparing a solution of the 
dye in di-n-butyl sebacate solvent (3% w/v). If the dye is insoluble, 
dissolution is achieved by the addition of some methylene chloride. The 
solution is filtered and 0.1-0.2 ml is applied to a clear polyethylene 
terephthalate support (approximately 4 cm.times.4 cm) and spun at 4,000 
RPM using the Spin Coating equipment, Model No. EC101, available from 
Headway Research Inc., Garland Tex. The transmission spectra of the so 
prepared dye samples are then recorded. 
Preferred "NB couplers" form a dye which, in n-butyl sebacate, has a LBW of 
the absorption spectra upon "spin coating" which is at least 15 nm, 
preferably at least 25 nm, less than that of the same dye in a 3% solution 
(w/v) in acetonitrile. 
In a preferred embodiment the cyan dye-forming "NB coupler" useful in the 
invention has the formula (IA) 
##STR3## 
wherein R' and R" are substituents selected such that the coupler is a "NB 
coupler", as herein defined; and 
Z is a hydrogen atom or a group which can be split off by the reaction of 
the coupler with an oxidized color developing agent. 
The coupler of formula (IA) is a 2,5-diamido phenolic cyan coupler wherein 
the substituents R' and R" are preferably independently selected from 
unsubstituted or substituted alkyl, aryl, amino, alkoxy and heterocyclyl 
groups. 
In a further preferred embodiment the "NB coupler" has the formula (I): 
##STR4## 
wherein R" and '" are independently selected from unsubstituted or 
substituted alkyl, aryl, amino, alkoxy and heterocyclyl groups and Z is as 
hereinbefore defined; 
R.sub.1 and R.sub.2 are independently hydrogen or an unsubstituted or 
substituted alkyl group; and 
Typically, R" is an alkyl, amino or aryl group, suitably a phenyl group. 
R'" is desirably an alkyl or aryl group or a 5-10 membered heterocyclic 
ring which contains one or more heteroatoms selected from nitrogen, oxygen 
and sulfur, which ring group is unsubstituted or substituted. 
In the preferred embodiment the coupler of formula (I) is a 2,5-diamido 
phenol in which the 5-amido moiety is an amide of a carboxylic acid which 
is substituted in the alpha position by a particular sulfone (--SO.sub.2 
--) group, such as, for example, described in U.S. Pat. No. 5,686,235. The 
sulfone moiety is an unsubstituted or substituted alkylsulfone or a 
heterocyclyl sulfone or it is an arylsulfone, which is preferably 
substituted, in particular in the meta and/or para position. 
Couplers having these structures of formulae (I) or (IA) comprise cyan 
dye-forming "NB couplers" which form image dyes having very sharp-cutting 
dye hues on the short wavelength side of the absorption curves with 
absorption maxima (.lambda..sub.max) which are shifted hypsochromically 
and are generally in the range of 620-645 nm, which is ideally suited for 
producing excellent color reproduction and high color saturation in color 
photographic papers. 
Referring to formula (I), R.sub.1 and R.sub.2 are independently hydrogen or 
an unsubstituted or substituted alkyl group, preferably having from 1 to 
24 carbon atoms and in particular 1 to 10 carbon atoms, suitably a methyl, 
ethyl, n-propyl, isopropyl, butyl or decyl group or an alkyl group 
substituted with one or more fluoro, chloro or bromo atoms, such as a 
trifluoromethyl group. Suitably, at least one of R.sub.1 and R.sub.2 is a 
hydrogen atom and if only one of R.sub.1 and R.sub.2 is a hydrogen atom 
then the other is preferably an alkyl group having 1 to 4 carbon atoms, 
more preferably one to three carbon atoms and desirably two carbon atoms. 
As used herein and throughout the specification unless where specifically 
stated otherwise, the term "alkyl" refers to an unsaturated or saturated 
straight or branched chain alkyl group, including alkenyl, and includes 
aralkyl and cyclic alkyl groups, including cycloalkenyl having 3-8 carbon 
atoms and the term `aryl` includes specifically fused aryl. 
In formula (I), R" is suitably an unsubstituted or substituted amino, alkyl 
or aryl group or a 5-10 membered heterocyclic ring which contains one or 
more heteroatoms selected from nitrogen, oxygen and sulfur, which ring is 
unsubstituted or substituted, but is more suitably an unsubstituted or 
substituted phenyl group. 
Examples of suitable substituent groups for this aryl or heterocyclic ring 
include cyano, chloro, fluoro, bromo, iodo, alkyl- or aryl-carbonyl, 
alkyl- or aryl-oxycarbonyl, carbonamido, alkyl- or aryl-carbonamido, 
alkyl- or aryl-sulfonyl, alkyl- or aryl-sulfonyloxy, alkyl- or 
aryl-oxysulfonyl, alkyl- or aryl-sulfoxide, alkyl- or aryl-sulfamoyl, 
alkyl- or aryl-sulfonamido, aryl, alkyl, alkoxy, aryloxy, nitro, alkyl- or 
aryl-ureido and alkyl- or aryl-carbamoyl groups, any of which may be 
further substituted. Preferred groups are halogen, cyano, alkoxycarbonyl, 
alkylsulfamoyl, alkyl-sulfonamido, alkylsulfonyl, carbamoyl, 
alkylcarbamoyl or alkylcarbonamido. Suitably, R" is a 4-chlorophenyl, 
3,4-dichlorophenyl, 3,4-difluorophenyl, 4-cyanophenyl, 
3-chloro-4-cyanophenyl, pentafluorophenyl, or a 3- or 4-sulfonamidophenyl 
group. 
In formula (I), when R'" is alkyl it may be unsubstituted or substituted 
with a substituent such as halogen or alkoxy. When R'" is aryl or a 
heterocycle, it may be substituted. Desirably it is not substituted in the 
position alpha to the sulfonyl group. 
In formula (I), when R'" is a phenyl group, it may be substituted in the 
meta and/or para positions with one to three substituents independently 
selected from the group consisting of halogen, and unsubstituted or 
substituted alkyl, alkoxy, aryloxy, acyloxy, acylamino, alkyl- or 
aryl-sulfonyloxy, alkyl- or aryl-sulfamoyl, alkyl- or aryl-sulfamoylamino, 
alkyl- or aryl-sulfonamido, alkyl- or aryl-ureido, alkyl- or 
aryl-oxycarbonyl, alkyl- or aryl-oxy-carbonylamino and alkyl- or 
aryl-carbamoyl groups. 
In particular each substituent may be an alkyl group such as methyl, 
t-butyl, heptyl, dodecyl, pentadecyl, octadecyl or 
1,1,2,2-tetramethylpropyl; an alkoxy group such as methoxy, t-butoxy, 
octyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy or octadecyloxy; an 
aryloxy group such as phenoxy, 4-t-butylphenoxy or 4-dodecyl-phenoxy; an 
alkyl- or aryl-acyloxy group such as acetoxy or dodecanoyloxy; an alkyl- 
or aryl-acylamino group such as acetamido, hexadecanamido or benzamido; an 
alkyl- or aryl-sulfonyloxy group such as methyl-sulfonyloxy, 
dodecylsulfonyloxy or 4-methylphenyl-sulfonyloxy; an alkyl- or 
aryl-sulfamoyl-group such as N-butylsulfamoyl or 
N-4-t-butylphenylsulfamoyl; an alkyl- or aryl-sulfamoylamino group such as 
N-butyl-sulfamoylamino or N-4-t-butylphenylsulfamoyl-amino; an alkyl- or 
aryl-sulfonamido group such as methane-sulfonamido, hexadecanesulfonamido 
or 4-chlorophenyl-sulfonamido; an alkyl- or aryl-ureido group such as 
methylureido or phenylureido; an alkoxy- or aryloxy-carbonyl such as 
methoxycarbonyl or phenoxycarbonyl; an alkoxy- or aryloxy-carbonylamino 
group such as methoxycarbonylamino or phenoxycarbonylamino; an alkyl- or 
aryl-carbamoyl group such as N-butylcarbamoyl or 
N-methyl-N-dodecylcarbamoyl; or a perfluoroalkyl group such as 
trifluoromethyl or heptafluoropropyl. 
Suitably the above substituent groups have 1 to 30 carbon atoms, more 
preferably 8 to 20 aliphatic carbon atoms. A desirable substituent is an 
alkyl group of 12 to 18 aliphatic carbon atoms such as dodecyl, pentadecyl 
or octadecyl or an alkoxy group with 8 to 18 aliphatic carbon atoms such 
as dodecyloxy and hexadecyloxy or a halogen such as a meta or para chloro 
group, carboxy or sulfonamido. Any such groups may contain interrupting 
heteroatoms such as oxygen to form e.g. polyalkylene oxides. 
In formula (I) or (IA) Z is a hydrogen atom or a group which can be split 
off by the reaction of the coupler with an oxidized color developing 
agent, known in the photographic art as a `coupling-off group` and may 
preferably be hydrogen, chloro, fluoro, substituted aryloxy or 
mercaptotetrazole, more preferably hydrogen or chloro. 
The presence or absence of such groups determines the chemical equivalency 
of the coupler, i.e., whether it is a 2-equivalent or 4-equivalent 
coupler, and its particular identity can modify the reactivity of the 
coupler. Such groups can advantageously affect the layer in which the 
coupler is coated, or other layers in the photographic recording material, 
by performing, after release from the coupler, functions such as dye 
formation, dye hue adjustment, development acceleration or inhibition, 
bleach acceleration or inhibition, electron transfer facilitation, color 
correction, and the like. 
Representative classes of such coupling-off groups include, for example, 
halogen, alkoxy, aryloxy, heterocyclyloxy, sulfonyloxy, acyloxy, acyl, 
heterocyclylsulfonamido, heterocyclylthio, benzothiazolyl, phosophonyloxy, 
alkylthio, arylthio, and arylazo. These coupling-off groups are described 
in the art, for example, in U.S. Pat. Nos. 2,455,169, 3,227,551, 
3,432,521, 3,467,563, 3,617,291, 3,880,661, 4,052,212, and 4,134,766; and 
in U.K. Patent Nos. and published applications 1,466,728, 1,531,927, 
1,533,039, 2,066,755A, and 2,017,704A, the disclosures of which are 
incorporated herein by reference. Halogen, alkoxy and aryloxy groups are 
most suitable. 
Examples of specific coupling-off groups are --Cl, --F, --Br, --SCN, 
--OCH.sub.3, --OC.sub.6 H.sub.5, --OCH.sub.2 C(.dbd.O)NHCH.sub.2 CH.sub.2 
OH, --OCH.sub.2 C(O)NHCH.sub.2 CH.sub.2 OCH.sub.3, --OCH.sub.2 
C(O)NHCH.sub.2 CH.sub.2 OC(.dbd.O)OCH.sub.3, --P(.dbd.O)(OC.sub.2 
H.sub.5).sub.2, --SCH.sub.2 CH.sub.2 COOH, 
##STR5## 
Typically, the coupling-off group is a chlorine atom, hydrogen atom or 
p-methoxyphenoxy group. 
It is essential that the substituent groups be selected so as to adequately 
ballast the coupler and the resulting dye in the organic solvent in which 
the coupler is dispersed. The ballasting may be accomplished by providing 
hydrophobic substituent groups in one or more of the substituent groups. 
Generally a ballast group is an organic radical of such size and 
configuration as to confer on the coupler molecule sufficient bulk and 
aqueous insolubility as to render the coupler substantially nondiffusible 
from the layer in which it is coated in a photographic element. Thus the 
combination of substituent are suitably chosen to meet these criteria. To 
be effective, the ballast will usually contain at least 8 carbon atoms and 
typically contains 10 to 30 carbon atoms. Suitable ballasting may also be 
accomplished by providing a plurality of groups which in combination meet 
these criteria. In the preferred embodiments of the invention R.sub.1 in 
formula (I) is a small alkyl group or hydrogen. Therefore, in these 
embodiments the ballast would be primarily located as part of the other 
groups. Furthermore, even if the coupling-off group Z contains a ballast 
it is often necessary to ballast the other substituents as well, since Z 
is eliminated from the molecule upon coupling; thus, the ballast is most 
advantageously provided as part of groups other than Z. 
The following examples further illustrate the invention. It is not to be 
construed that the present invention is limited to these examples. 
##STR6## 
Preferred couplers are IC-3, IC-7, IC-35, and IC-36 because of their 
suitably narrow left bandwidths. 
Unless otherwise specifically stated, substituent groups which may be 
substituted on molecules herein include any groups, whether substituted or 
unsubstituted, which do not destroy properties necessary for photographic 
utility. When the term "group" is applied to the identification of a 
substituent containing a substitutable hydrogen, it is intended to 
encompass not only the substituent's unsubstituted form, but also its form 
further substituted with any group or groups as herein mentioned. 
Suitably, the group may be halogen or may be bonded to the remainder of 
the molecule by an atom of carbon, silicon, oxygen, nitrogen, phosphorous, 
or sulfur. The substituent may be, for example, halogen, such as chlorine, 
bromine or fluorine; nitro; hydroxyl; cyano; carboxyl; or groups which may 
be further substituted, such as alkyl, including straight or branched 
chain alkyl, such as methyl, trifluoromethyl, ethyl, t-butyl, 
3-(2,4-di-t-pentylphenoxy) propyl, and tetradecyl; alkenyl, such as 
ethylene, 2-butene; alkoxy, such as methoxy, ethoxy, propoxy, butoxy, 
2-methoxyethoxy, sec-butoxy, hexyloxy, 2-ethylhexyloxy, tetradecyloxy, 
2-(2,4-di-t-pentylphenoxy)ethoxy, and 2-dodecyloxyethoxy; aryl such as 
phenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, naphthyl; aryloxy, such as 
phenoxy, 2-methylphenoxy, alpha- or beta-naphthyloxy, and 4-tolyloxy; 
carbonamido, such as acetamido, benzamido, butyramido, tetradecanamido, 
alpha-(2,4-di-t-pentyl-phenoxy)acetamido, 
alpha-(2,4-di-t-pentylphenoxy)butyramido, 
alpha-(3-pentadecylphenoxy)-hexanamido, 
alpha-(4-hydroxy-3-t-butylphenoxy)-tetradecanamido, 2-oxo-pyrrolidin-1-yl, 
2-oxo-5-tetradecylpyrrolin-1-yl, N-methyltetradecanamido, N-succinimido, 
N-phthalimido, 2,5-dioxo-1 -oxazolidinyl, 
3-dodecyl-2,5-dioxo-1-imidazolyl, and N-acetyl-N-dodecylamino, 
ethoxycarbonylamino, phenoxycarbonylamino, benzyloxycarbonylamino, 
hexadecyloxycarbonylamino, 2,4-di-t-butylphenoxycarbonylamino, 
phenylcarbonylamino, 2,5-(di-t-pentylphenyl)carbonylamino, 
p-dodecyl-phenylcarbonylamino, p-toluylcarbonylamino, N-methylureido, 
N,N-dimethylureido, N-methyl-N-dodecylureido, N-hexadecylureido, 
N,N-dioctadecylureido, N,N-dioctyl-N'-ethylureido, N-phenylureido, 
N,N-diphenylureido, N-phenyl-N-p-toluylureido, 
N-(m-hexadecylphenyl)ureido, N,N-(2,5-di-t-pentylphenyl)-N'-ethylureido, 
and t-butylcarbonamido; sulfonamido, such as methylsulfonamido, 
benzenesulfonamido, p-toluylsulfonamido, p-dodecylbenzenesulfonamido, 
N-methyltetradecylsulfonamido, N,N-dipropyl-sulfamoylamino, and 
hexadecylsulfonamido; sulfamoyl, such as N-methylsulfamoyl, 
N-ethylsulfamoyl, N,N-dipropylsulfamoyl, N-hexadecylsulfamoyl, 
N,N-dimethylsulfamoyl; N-[3-(dodecyloxy)propyl]sulfamoyl, 
N-[4-(2,4-di-t-pentylphenoxy)butyl]sulfamoyl, 
N-methyl-N-tetradecylsulfamoyl, and N-dodecylsulfamoyl; carbamoyl, such as 
N-methylcarbamoyl, N,N-dibutylcarbamoyl, N-octadecylcarbamoyl, 
N-[4-(2,4-di-t-pentylphenoxy)butyl]carbamoyl, 
N-methyl-N-tetradecylcarbamoyl, and N,N-dioctylcarbamoyl; acyl, such as 
acetyl, (2,4-di-t-amylphenoxy)acetyl, phenoxycarbonyl, 
p-dodecyloxyphenoxycarbonyl, methoxycarbonyl, butoxycarbonyl, 
tetradecyloxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl, 
3-pentadecyloxycarbonyl, and dodecyloxycarbonyl; sulfonyl, such as 
methoxysulfonyl, octyloxysulfonyl, tetradecyloxysulfonyl, 
2-ethylhexyloxysulfonyl, phenoxysulfonyl, 2,4-di-t-pentylphenoxysulfonyl, 
methylsulfonyl, octylsulfonyl, 2-ethylhexylsulfonyl, dodecylsulfonyl, 
hexadecylsulfonyl, phenylsulfonyl, 4-nonylphenylsulfonyl, and 
p-toluylsulfonyl; sulfonyloxy, such as dodecylsulfonyloxy, and 
hexadecylsulfonyloxy; sulfinyl, such as methylsulfinyl, octylsulfinyl, 
2-ethylhexylsulfinyl, dodecylsulfinyl, hexadecylsulfinyl, phenylsulfinyl, 
4-nonylphenylsulfinyl, and p-toluylsulfinyl; thio, such as ethylthio, 
octylthio, benzylthio, tetradecylthio, 
2-(2,4-di-t-pentylphenoxy)ethylthio, phenylthio, 
2-butoxy-5-t-octylphenylthio, and p-tolylthio; acyloxy, such as acetyloxy, 
benzoyloxy, octadecanoyloxy, p-dodecylamidobenzoyloxy, 
N-phenylcarbamoyloxy, N-ethylcarbamoyloxy, and cyclohexylcarbonyloxy; 
amino, such as phenylanilino, 2-chloroanilino, diethylamino, dodecylamino; 
imino, such as 1 (N-phenylimido)ethyl, N-succinimido or 
3-benzylhydantoinyl; phosphate, such as dimethylphosphate and 
ethylbutylphosphate; phosphite, such as diethyl and dihexylphosphite; a 
heterocyclic group, a heterocyclic oxy group or a heterocyclic thio group, 
each of which may be substituted and which contain a 3 to 7 membered 
heterocyclic ring composed of carbon atoms and at least one hetero atom 
selected from the group consisting of oxygen, nitrogen and sulfur, such as 
2-furyl, 2-thienyl, 2-benzimidazolyloxy or 2-benzothiazolyl; quaternary 
ammonium, such as triethylammonium; and silyloxy, such as 
trimethylsilyloxy. 
If desired, the substituents may themselves be further substituted one or 
more times with the described substituent groups. The particular 
substituents used may be selected by those skilled in the art to attain 
the desired photographic properties for a specific application and can 
include, for example, hydrophobic groups, solubilizing groups, blocking 
groups, releasing or releasable groups, etc. Generally, the above groups 
and substituents thereof may include those having up to 48 carbon atoms, 
typically 1 to 36 carbon atoms and usually less than 24 carbon atoms, but 
greater numbers are possible depending on the particular substituents 
selected. 
Representative substituents on ballast groups include alkyl, aryl, alkoxy, 
aryloxy, alkylthio, hydroxy, halogen, alkoxycarbonyl, aryloxcarbonyl, 
carboxy, acyl, acyloxy, amino, anilino, carbonamido, carbamoyl, 
alkylsulfonyl, arylsulfonyl, sulfonamido, and sulfamoyl groups wherein the 
substituents typically contain 1 to 42 carbon atoms. Such substituents can 
also be further substituted. 
The high boiling solvent of the invention can be described by the general 
formula (II), 
EQU R.sup.3 OO--C--(--G--)--C--OO--R.sup.4 (II) 
wherein R.sup.3 and R.sup.4 represent independently selected alkyl or aryl 
groups. G represents an alkyl (including cycloalkyl and aralkyl) 
containing linking group. 
R.sup.3 and R.sup.4 are independently selected alkyl groups such as methyl, 
ethyl, propyl, butyl, octyl, 2-ethylhexyl, and decyl groups; and aryl 
groups such as a methylphenyl group. 
G represents an alkyl containing linking group, either linear or cyclized, 
such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, 
decyl, undecyl, dodecyl, cyclohexyl, or cyclohexenyl. G may also be 
substituted along the alkyl chain by one or more groups such as --OH, 
--OCOR, --COR, --OR, --COOR, --CN, and halogen where R is H or a 
substituent. 
Preferably R.sup.3 and R.sup.4 are alkyl groups and G is an unsubstituted 
alkyl group or an alkyl group substituted with a hydroxy and/or one or 
more carboxylic ester groups. 
The term high-boiling means solvents boiling above 100.degree. C., 
typically above 140.degree. C. The following solvents further illustrate a 
preferred embodiment of the invention. It is not to be construed that the 
present invention is limited to these examples. 
##STR7## 
The stabilizers of the invention can be described by the general Formula 
(III): 
##STR8## 
wherein each Y is an independently selected substituent and m is 0 to 4; 
and 
each T is an independently selected substituent and p is 0 to 4. 
Suitably each Y is independently selected from hydrogen, halogen, nitro, 
and a substituent selected from the group consisting of unsubstituted or 
substituted alkyl, aryl, alkoxy, aryloxy, acyloxy, alkyl- or aryl-thio, 
mono- or di-alkylamino, acylamino, alkoxycarbonyl and a 5-membered or 
6-membered heterocyclic group containing a nitrogen, oxygen or sulfur 
atom, and m is 0 to 4; and 
each T is independently selected from hydrogen, halogen and a substituent 
selected from the group consisting of unsubstituted or substituted alkyl, 
aryl, alkoxy, aryloxy, acyloxy, alkyl- or aryl-thio, mono- or 
di-alkylamino, acylamino, and a 5-membered or 6-membered heterocyclic 
group containing a nitrogen, oxygen or sulfur atom, and p is 0 to 4. 
More preferably the 5-position of the benzotriazole ring is unsubstituted 
or substituted with an unsubstituted alkyl group and/or the 6-position is 
unsubstituted or substituted with a chlorine atom. Furthermore the 3' and 
5' positions of the phenyl ring are preferably unsubstituted and the 2'- 
and/or 4'-positions are preferably substituted with an unsubstituted or 
substituted alkyl group, especially a branched alkyl group such as a 
t-butyl, t-pentyl or 2-ethylhexyl group. More preferably the ring is 
di-substituted at the 2'- and 4'-positions. 
The following stabilizers further illustrate the invention. It is not to be 
construed that the present invention is limited to these examples. 
##STR9## 
Embodiments of the invention enable the use of lower amounts of coupler and 
silver by improving the efficiency with which oxidized color developer 
reacts with the coupler to form dye. Embodiments of the invention exhibit 
reduction of low unwanted side-band absorption, especially unwanted green 
absorption and provide dye evidencing improved stability to light, heat, 
and humidity and improved hue. 
The dispersion of the "NB Couplers" and stabilizers for use in the 
invention can be prepared by dissolving the materials in one or more 
high-boiling permanent organic solvents, including those solvents 
represented by formula (II), with or without a low-boiling or partially 
water-soluble auxiliary organic solvent. The resulting organic solution 
may then be mixed with an aqueous gelatin solution, and the mixture passed 
through a mechanical mixing device suitable for high-shear or turbulent 
mixing generally suitable for preparing photographic emulsified 
dispersions, such as a colloid mill, homogenizer, microfluidizer, 
high-speed mixer, ultrasonic dispersing apparatus, blade mixer, device in 
which a liquid stream is pumped at high pressure through an orifice or 
interaction chamber, Gaulin mill or blender to form small particles of the 
organic phase suspended in the aqueous phase. More than one type of device 
may be used to prepare the dispersions. The auxiliary organic solvent may 
then removed by evaporation, noodle washing, or membrane dialysis. The 
dispersion particles preferably have an average particle size of less than 
2 .mu.m, generally from about 0.02 to 2 .mu.m, more preferably from about 
0.02 to 0.5 .mu.m, especially from about 0.02 to 0.3 .mu.m. These methods 
are described in detail in U.S. Pat. Nos. 2,322,027, 2,787,544, 2,801,170, 
2,801,171, 2,949,360, and 3,396,027, the disclosures of which are 
incorporated by reference herein. 
Examples of suitable auxiliary solvents which can be used in the present 
invention include: ethyl acetate, isopropyl acetate, butyl acetate, ethyl 
propionate, 2-ethoxyethylacetate, 2-(2-butoxyethoxy) ethyl acetate, 
dimethylformamide, 2-methyl tetrahydrofuran, triethyl-phosphate, 
cyclohexanone, butoxyethyl acetate, methyl isobutyl ketone, methyl 
acetate, 4-methyl-2-pentanol, diethyl carbitol, 1,1,2-trichloroethane and 
1,2-dichloropropane. 
The aqueous phase of the coupler dispersions for use in the invention 
preferably comprise gelatin as a hydrophilic colloid. This may be gelatin 
or a modified gelatin such as acetylated gelatin, phthalated gelatin or 
oxidized gelatin. Gelatin may be base-processed, such as lime-processed 
gelatin, or may be acid-processed, such as acid processed ossein gelatin. 
Other hydrophilic colloids may also be used, such as a water-soluble 
polymer or copolymer including, but not limited to poly(vinyl alcohol), 
partially hydrolyzed poly(vinyl acetate-co-vinyl alcohol), hydroxyethyl 
cellulose, poly(acrylic acid), poly(1-vinylpyrrolidone), poly(sodium 
styrene sulfonate), poly(2-acrylamido-2-methane sulfonic acid), 
polyacrylamide. Copolymers of these polymers with hydrophobic monomers may 
also be used. 
A surfactant may be present in either the aqueous phase or the organic 
phase or the dispersions can be prepared without any surfactant present. 
Surfactants may be cationic, anionic, zwitterionic or non-ionic. Ratios of 
surfactant to liquid organic solution typically are in the range of 0.5 to 
25 wt. % for forming small particle photographic dispersions. In a 
preferred embodiment of the invention, an anionic surfactant is contained 
in the aqueous gelatin solution. Particularly preferred surfactants which 
are employed in the present invention include an alkali metal salt of an 
alkarylene sulfonic acid, such as the sodium salt of dodecyl benzene 
sulfonic acid or sodium salts of isopropylnaphthalene sulfonic acids, such 
as mixtures of di-isopropyl- and tri-isopropylnaphthalene sodium 
sulfonates; an alkali metal salt of an alkyl sulfuric acid, such as sodium 
dodecyl sulfate; or an alkali metal salt of an alkyl sulfosuccinate, such 
as sodium bis (2-ethylhexyl) succinic sulfonate. 
In an alternative embodiment, the "NB Coupler" may be dispersed without any 
high-boiling organic solvent. This could take the form of 
microprecipitated dispersions of photographic couplers prepared by solvent 
and/or pH shift techniques (see references: U.K. Patent No. 1,193,349; 
Research Disclosure 16468, December 1977 pp.75-80; U.S. Pat. Nos. 
4,970,139; 5,089,380; 5,008,179; 5,104,776). These no-solvent coupler 
dispersions could be combined with a separate dispersion containing one or 
more high boiling solvents, or more specifically, which includes at least 
one solvent of formula (II) in an aqueous coating solution. 
Aqueous dispersions of high-boiling solvents of formulae (II) can be 
prepared similarly to the coupler dispersion, e.g., by adding the solvent 
to an aqueous medium and subjecting such mixture to high shear or 
turbulent mixing as described above. The aqueous medium is preferably a 
gelatin solution, and surfactants and auxiliary solvents may also be used 
as described above. Additionally, a hydrophobic additive may be dissolved 
in the solvent to prevent particle growth as described in U.S. Pat. No. 
5,468,604, the disclosure of which is incorporated by reference. The 
mixture is then passed through a mechanical mixing device such as a 
colloid mill, homogenizer, microfluidizer, high speed mixer or ultrasonic 
dispersing apparatus to form small particles of the organic solvent 
suspended in the aqueous phase. If an auxiliary solvent is employed, it is 
then subsequently removed by evaporation, noodle washing, or membrane 
dialysis. These methods are described in detail in the aforementioned 
references on dispersion making. The solvent dispersion may be a "blank" 
dispersion which does not contain any additional photographically useful 
compounds, or the solvent may be part of a photographically useful 
compound dispersion. 
An aqueous coating solution in accordance with the present invention may 
then be prepared by combining a cyan coupler dispersion with the separate 
dispersion of the high-boiling organic solvent of formula (II). Other 
ingredients may also be contained in this solution such as silver halide 
emulsions, dispersions or solutions of other photographically useful 
compounds, additional gelatin, or acids and bases to adjust the pH. These 
ingredients may then be mixed with a mechanical device at an elevated 
temperature (e.g. 30 to 50.degree. C.) for a short period of time (e.g. 5 
min to 4 h) prior to coating. 
Typically, the invention materials are incorporated in a silver halide 
emulsion and the emulsion coated as a layer on a support to form part of a 
photographic element. Alternatively, unless provided otherwise, they can 
be incorporated at a location adjacent to the silver halide emulsion layer 
where, during development, they will be in reactive association with 
development products such as oxidized color developing agent. Thus, as 
used herein, the term "associated" signifies that the compound is in the 
silver halide emulsion layer or in an adjacent layer. 
The photographic elements can be single color elements or multicolor 
elements. Multicolor elements contain image dye-forming units sensitive to 
each of the three primary regions of the spectrum. Each unit can comprise 
a single emulsion layer or multiple emulsion layers sensitive to a given 
region of the spectrum. The layers of the element, including the layers of 
the image-forming units, can be arranged in various orders as known in the 
art. In an alternative format, the emulsions sensitive to each of the 
three primary regions of the spectrum can be disposed as a single 
segmented layer. 
A typical multicolor photographic element comprises a support bearing a 
cyan dye image-forming unit comprised of at least one red-sensitive silver 
halide emulsion layer having associated therewith at least one cyan 
dye-forming coupler, a magenta dye image-forming unit comprising at least 
one green-sensitive silver halide emulsion layer having associated 
therewith at least one magenta dye-forming coupler, and a yellow dye 
image-forming unit comprising at least one blue-sensitive silver halide 
emulsion layer having associated therewith at least one yellow dye-forming 
coupler. The element can contain additional layers, such as filter layers, 
interlayers, overcoat layers, subbing layers, and the like. 
If desired, the photographic element can be used in conjunction with an 
applied magnetic layer as described in Research Disclosure, November 1992, 
Item 34390 published by Kenneth Mason Publications, Ltd., Dudley Annex, 
12a North Street, Emsworth, Hampshire P010 7DQ, ENGLAND, and as described 
in Hatsumi Kyoukai Koukai Gihou No. 94-6023, published Mar. 15, 1994, 
available from the Japanese Patent Office, the contents of which are 
incorporated herein by reference. When it is desired to employ the 
inventive materials in a small format film, Research Disclosure, June 
1994, Item 36230, provides suitable embodiments. 
In the following discussion of suitable materials for use in the emulsions 
and elements of this invention, reference will be made to Research 
Disclosure, September 1994, Item 36544, available as described above, 
which will be identified hereafter by the term "Research Disclosure". The 
contents of the Research Disclosure, including the patents and 
publications referenced therein, are incorporated herein by reference, and 
the Sections hereafter referred to are Sections of the Research 
Disclosure. 
Except as provided, the silver halide emulsion containing elements employed 
in this invention can be either negative-working or positive-working as 
indicated by the type of processing instructions (i.e. color negative, 
reversal, or direct positive processing) provided with the element. 
Suitable emulsions and their preparation as well as methods of chemical 
and spectral sensitization are described in Sections I through V. Various 
additives such as UV dyes, brighteners, antifoggants, stabilizers, light 
absorbing and scattering materials, and physical property modifying 
addenda such as hardeners, coating aids, plasticizers, lubricants and 
matting agents are described, for example, in Sections II and VI through 
VIII. Color materials are described in Sections X through XIII. Scan 
facilitating is described in Section XIV. Supports, exposure, development 
systems, and processing methods and agents are described in Sections XV to 
XX. Certain desirable photographic elements and processing steps, 
particularly those useful in conjunction with color reflective prints, are 
described in Research Disclosure, Item 37038, February 1995. 
Couplers that form magenta dyes upon reaction with oxidized color 
developing agent are described in such representative patents and 
publications as: U.S. Pat. Nos. 2,311,082, 2,343,703, 2,369,489, 
2,600,788, 2,908,573, 3,062,653, 3,152,896, 3,519,429, 3,758,309, and 
"Farbkuppler-eine Literature Ubersicht," published in Agfa Mitteilungen, 
Band III, pp. 126-156 (1961). Preferably such couplers are pyrazolones, 
pyrazolotriazoles, or pyrazolobenzimidazoles that form magenta dyes upon 
reaction with oxidized color developing agents. Especially preferred 
couplers are 1H-pyrazolo [5,1-c]-1,2,4-triazole and 1H-pyrazolo 
[1,5-b]-1,2,4-triazole. Examples of 1H-pyrazolo [5,1-c]-1,2,4-triazole 
couplers are described in U.K. Patent Nos. 1,247,493; 1,252,418; 
1,398,979; U.S. Pat. Nos. 4,443,536; 4,514,490; 4,540,654; 4,590,153; 
4,665,015; 4,822,730; 4,945,034; 5,017,465; and 5,023,170. Examples of 
1H-pyrazolo [1,5-b]-1,2,4-triazoles can be found in European Patent 
applications 176,804; 177,765; U.S. Pat. Nos. 4,659,652; 5,066,575; and 
5,250,400. 
Typical pyrazoloazole and pyrazolone couplers are represented by the 
following formulas: 
##STR10## 
wherein R.sub.a and R.sub.b independently represent H or a substituent; 
R.sub.c is a substituent (preferably an aryl group); R.sub.d is a 
substituent (preferably an anilino, carbonamido, ureido, carbamoyl, 
alkoxy, aryloxycarbonyl, alkoxycarbonyl, or N-heterocyclic group); X is 
hydrogen or a coupling-off group; and Z.sub.a, Z.sub.b, and Z.sub.c are 
independently a substituted methine group, .dbd.N--, .dbd.C--, or --NH--, 
provided that one of either the Z.sub.a --Z.sub.b bond or the Z.sub.b 
--Z.sub.c bond is a double bond and the other is a single bond, and when 
the Z.sub.b --Z.sub.c bond is a carbon--carbon double bond, it may form 
part of an aromatic ring, and at least one of Z.sub.a, Z.sub.b, and 
Z.sub.c represents a methine group connected to the group R.sub.b. 
Specific examples of such couplers are: 
##STR11## 
Couplers that form yellow dyes upon reaction with oxidized color developing 
agent are described in such representative patents and publications as: 
U.S. Pat. Nos. 2,298,443, 2,407,210, 2,875,057, 3,048,194, 3,265,506, 
3,447,928, 3,960,570, 4,022,620, 4,443,536, 4,910,126 and 5,340,703 and 
"Farbkuppler-eine Literature Ubersicht," published in Agfa Mitteilungen, 
Band III, pp. 112-126 (1961). Such couplers are typically open chain 
ketomethylene compounds. Also preferred are yellow couplers such as 
described in, for example, European Patent Application Nos. 482,552; 
510,535; 524,540; 543,367; and U.S. Pat. No. 5,238,803. For improved color 
reproduction, couplers which give yellow dyes that cut off sharply on the 
long wavelength side are particularly preferred (for example, see U.S. 
Pat. No. 5,360,713). 
Typical preferred yellow couplers are represented by the following 
formulas: 
##STR12## 
wherein R.sub.1, R.sub.2, Q.sub.1 and Q.sub.2 each represent a 
substituent; X is hydrogen or a coupling-off group; Y represents an aryl 
group or a heterocyclic group; Q.sub.3 represents an organic residue 
required to form a nitrogen-containing heterocyclic group together with 
the &gt;N--; and Q.sub.4 represents nonmetallic atoms necessary to from a 3- 
to 5-membered hydrocarbon ring or a 3- to 5-membered heterocyclic ring 
which contains at least one hetero atom selected from N, O, S, and P in 
the ring. Particularly preferred is when Q.sub.1 and Q.sub.2 each 
represent an alkyl group, an aryl group, or a heterocyclic group, and 
R.sub.2 represents an aryl or tertiary alkyl group. 
Preferred yellow couplers can be of the following general structures 
##STR13## 
Couplers that form colorless products upon reaction with oxidized color 
developing agent are described in such representative patents as: U.K. 
Patent No. 861,138; U.S. Pat. Nos. 3,632,345, 3,928,041, 3,958,993 and 
3,961,959. Typically such couplers are cyclic carbonyl containing 
compounds that form colorless products on reaction with an oxidized color 
developing agent. 
Couplers that form black dyes upon reaction with oxidized color developing 
agent are described in such representative patents as U.S. Pat. Nos. 
1,939,231; 2,181,944; 2,333,106; and 4,126,461; German OLS No. 2,644,194 
and German OLS No. 2,650,764. Typically, such couplers are resorcinols or 
m-aminophenols that form black or neutral products on reaction with 
oxidized color developing agent. 
In addition to the foregoing, so-called "universal" or "washout" couplers 
may be employed. These couplers do not contribute to image dye-formation. 
Thus, for example, a naphthol having an unsubstituted carbamoyl or one 
substituted with a low molecular weight substituent at the 2- or 
3-position may be employed. Couplers of this type are described, for 
example, in U.S. Pat. Nos. 5,026,628, 5,151,343, and 5,234,800. 
It may be useful to use a combination of couplers any of which may contain 
known ballasts or coupling-off groups such as those described in U.S. Pat. 
No. 4,301,235; U.S. Pat. No. 4,853,319 and U.S. Pat. No. 4,351,897. The 
coupler may contain solubilizing groups such as described in U.S. Pat. No. 
4,482,629. The coupler may also be used in association with "wrong" 
colored couplers (e.g. to adjust levels of interlayer correction) and, in 
color negative applications, with masking couplers such as those described 
in EP 213.490; Japanese Published Application 58-172,647; U.S. Pat. Nos. 
2,983,608; 4,070,191; and 4,273,861; German Applications DE 2,706,117 and 
DE 2,643,965; UK. Patent 1,530,272; and Japanese Application 58-113935. 
The masking couplers may be shifted or blocked, if desired. 
The invention materials may be used in association with materials that 
accelerate or otherwise modify the processing steps e.g. of bleaching or 
fixing to improve the quality of the image. Bleach accelerator releasing 
couplers such as those described in EP 193,389; EP 301,477; U.S. Pat. No. 
4,163,669; U.S. Pat. No. 4,865,956; and U.S. Pat. No. 4,923,784, may be 
useful. Also contemplated is use of the compositions in association with 
nucleating agents, development accelerators or their precursors (UK Patent 
2,097,140; UK. Patent 2,131,188); electron transfer agents (U.S. Pat. No. 
4,859,578; U.S. Pat. No. 4,912,025); antifogging and anticolor-mixing 
agents such as derivatives of hydroquinones, aminophenols, amines, gallic 
acid; catechol; ascorbic acid; hydrazides; sulfonamidophenols; and non 
color-forming couplers. 
The invention materials may also be used in combination with filter dye 
layers comprising colloidal silver sol or yellow, cyan, and/or magenta 
filter dyes, either as oil-in-water dispersions, latex dispersions or as 
solid particle dispersions. Additionally, they may be used with "smearing" 
couplers (e.g. as described in U.S. Pat. No. 4,366,237; EP 96,570; U.S. 
Pat. No. 4,420,556; and U.S. Pat. No. 4,543,323.) Also, the compositions 
may be blocked or coated in protected form as described, for example, in 
Japanese Application 61/258,249 or U.S. Pat. No. 5,019,492. 
The invention materials may further be used in combination with 
image-modifying compounds such as "Developer Inhibitor-Releasing" 
compounds (DIR's). DIR's useful in conjunction with the compositions of 
the invention are known in the art and examples are described in U.S. Pat. 
Nos. 3,137,578; 3,148,022; 3,148,062; 3,227,554; 3,384,657; 3,379,529; 
3,615,506; 3,617,291; 3,620,746; 3,701,783; 3,733,201; 4,049,455; 
4,095,984; 4,126,459; 4,149,886; 4,150,228; 4,211,562; 4,248,962; 
4,259,437; 4,362,878; 4,409,323; 4,477,563; 4,782,012; 4,962,018; 
4,500,634; 4,579,816; 4,607,004; 4,618,571; 4,678,739; 4,746,600; 
4,746,601; 4,791,049; 4,857,447; 4,865,959; 4,880,342; 4,886,736; 
4,937,179; 4,946,767; 4,948,716; 4,952,485; 4,956,269; 4,959,299; 
4,966,835; 4,985,336 as well as in patent publications GB 1,560,240; GB 
2,007,662; GB 2,032,914; GB 2,099,167; DE 2,842,063, DE 2,937,127; DE 
3,636,824; DE 3,644,416 as well as the following European Patent 
Publications: 272,573; 335,319; 336,411; 346, 899; 362, 870; 365,252; 
365,346; 373,382; 376,212; 377,463; 378,236; 384,670; 396,486; 401,612; 
401,613. 
It is also contemplated that the concepts of the present invention may be 
employed to obtain reflection color prints as described in Research 
Disclosure, November 1979, Item 18716, available from Kenneth Mason 
Publications, Ltd, Dudley Annex, 12a North Street, Emsworth, Hampshire 
P0101 7DQ, England, incorporated herein by reference. Materials of the 
invention may be coated on pH adjusted support as described in U.S. Pat. 
No. 4,917,994; on a support with reduced oxygen permeability (EP 553,339); 
with epoxy solvents (EP 164,961); with nickel complex stabilizers (U.S. 
Pat. No. 4,346,165; U.S. Pat. No. 4,540,653 and U.S. Pat. No. 4,906,559 
for example); with ballasted chelating agents such as those in U.S. Pat. 
No. 4,994,359 to reduce sensitivity to polyvalent cations such as calcium; 
and with stain reducing compounds such as described in U.S. Pat. No. 
5,068,171. Other compounds useful in combination with the invention are 
disclosed in Japanese Published Applications described in Derwent 
Abstracts having accession numbers as follows: 90-072,629, 90-072,630; 
90-072,631; 90-072,632; 90-072,633; 90-072,634; 90-077,822; 90-078,229; 
90-078,230; 90-079,336; 90-079,337; 90-079,338; 90-079,690; 90-079,691; 
90-080,487; 90-080,488; 90-080,489; 90-080,490; 90-080,491; 90-080,492; 
90-080,494; 90-085,928; 90-086,669; 90-086,670; 90-087,360; 90-087,361; 
90-087,362; 90-087,363; 90-087,364; 90-088,097; 90-093,662; 90-093,663; 
90-093,664; 90-093,665; 90-093,666; 90-093,668; 90-094,055; 90-094,056; 
90-103,409; 83-62,586; 83-09,959. Useful supports include those described 
in U.S. Pat. No. 5,866,282. 
Any silver halide combination can be used for the photographic element, 
such as silver chloride, silver chlorobromide, silver chlorobromoiodide, 
silver bromide, silver bromoiodide, or silver chloroiodide. In cases where 
the emulsion composition is a mixed halide, the minor component may be 
added in the crystal formation or after formation as part of the 
sensitization or melting. The shape of the silver halide emulsion grain 
can be cubic, pseudo-cubic, octahedral, tetradecahedral or tabular. The 
emulsions may be precipitated in any suitable environment such as a 
ripening environment, a reducing environment or an oxidizing environment. 
The emulsions can be surface-sensitive emulsions, i.e., emulsions that form 
latent images primarily on the surfaces of the silver halide grains, or 
the emulsions can form internal latent images predominantly in the 
interior of the silver halide grains. The emulsions can be 
negative-working emulsions, such as surface-sensitive emulsions or 
unfogged internal latent image-forming emulsions, or direct-positive 
emulsions of the unfogged, internal latent image-forming type, which are 
positive-working when development is conducted with uniform light exposure 
or in the presence of a nucleating agent. 
Photographic elements can be exposed to actinic radiation, typically in the 
visible region of the spectrum, to form a latent image and can then be 
processed to form a visible dye image. Processing to form a visible dye 
image includes the step of contacting the element with a color developing 
agent to reduce developable silver halide and oxidize the color developing 
agent. Oxidized color developing agent in turn reacts with the coupler to 
yield a dye. 
With negative-working silver halide, the processing step described above 
provides a negative image. The described elements can be processed in the 
known Kodak C-41 color process as described in The British Journal of 
Photography Annual of 1988, pages 191-198. Where applicable, the element 
may be processed in accordance with color print processes such as the RA-4 
process of Eastman Kodak Company as described in the British Journal of 
Photography Annual of 1988, Pp 198-199. Such negative working emulsions 
are typically sold with instructions to process using a color negative 
method such as the mentioned C-41 or RA-4 process. To provide a positive 
(or reversal) image, the color development step can be preceded by 
development with a non-chromogenic developing agent to develop exposed 
silver halide, but not form dye, and followed by uniformly fogging the 
element to render unexposed silver halide developable. Such reversal 
emulsions are typically sold with instructions to process using a color 
reversal process such as E-6. Alternatively, a direct positive emulsion 
can be employed to obtain a positive image. 
Preferred color developing agents are p-phenylenediamines such as: 
4-amino-N,N-diethylaniline hydrochloride, 
4-amino-3-methyl-N,N-diethylaniline hydrochloride, 
4-amino-3-methyl-N-ethyl-N-(2-methanesulfonamido-ethyl)aniline 
sesquisulfate hydrate, 
4-amino-3-methyl-N-ethyl-N-(2-hydroxyethyl)aniline sulfate, 
4-amino-3-(2-methanesulfonamido-ethyl)-N,N-diethylaniline hydrochloride and 
4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene sulfonic acid. 
Development is usually followed by the conventional steps of bleaching, 
fixing, or bleach-fixing, to remove silver or silver halide, washing, and 
drying. 
The coupler dispersions could be coated with emulsions to form photographic 
elements at very low levels of silver (less than 100 mg/m.sup.2). Reasons 
for doing this include reducing cost, reducing the thickness of silver 
halide emulsion layers to gain sharpness advantages and reducing the 
environmental impact during and after processing. 
One class of low silver photographic material is color material intended 
for redox amplification processes wherein the developed silver acts as a 
catalyst to the formation of the dye image. This process can take place in 
a low volume thin processor, such as a low volume thin tank (LVTT), for 
example, disclosed in U.S. Pat. No. 5,436,118. Redox amplification 
processes have been described for example in GB 1,268,126, GB 1,399,481, 
GB 1,403,418, GB 1,560,572, U.S. Pat. No. 3,748,138, U.S. Pat. No. 
3,822,129 and U.S. Pat. No. 4,097,278. In such processes, color materials 
are developed to produce a silver image (which may contain only small 
amounts of silver) and are then treated with a redox amplifying solution 
(or a combined developer-amplifier) to form a dye image. 
EXAMPLE 1 
Determination of "NB Couplers" 
Using procedures known to those skilled in synthetic chemistry, such as 
described in J. Bailey, JCS Perkin 1, 1977, 2047, the dyes of the couplers 
in Table 1 below were prepared by coupling with 
4-amino-3-methyl-N-ethyl-N-(2-methane-sulfonamidoethyl) aniline 
sesquisulfate hydrate, then purified by either crystallization or 
chromatographic techniques. 
A 3% w/v solution of di-n-butyl sebacate (solvent S-1) was made with ethyl 
acetate and from this solution a 3% solution of the dye based on solvent 
S-1 was prepared. If the dye was insoluble, dissolution was achieved by 
the addition of some methylene chloride. The solution was filtered and 
0.1-0.2 ml was applied to a clear polyethylene-terephthalate support 
(approx. 4 cm.times.4 cm) and spun at 4000 RPM using the Spin-Coating 
equipment, Model No. EC101, available from Headway Research Inc., Garland 
Tex. The normalized (density of 1.00) transmission spectra of the 
so-prepared dye samples were then recorded. The transmission spectra of 
the same dye in acetonitrile was also measured and normalized to a density 
of 1.00. 
The .lambda..sub.max values, "half bandwidth" (HBW), and "left bandwidth" 
(LBW) values for each normalized spectra are reported in Table 1 below. 
The wavelength of maximum absorption was recorded as the .lambda.max. The 
half bandwidth (HBW) was obtained by subtracting the wavelength at the 
point on the left side (short wavelength) of the absorption band where the 
normalized density is 0.50 from the wavelength at the point on the right 
side (long wavelength) of the absorption band where the normalized density 
is 0.50. The left bandwidth (LBW) was obtained by subtracting the 
wavelength at the point on the left side (short wavelength) of the 
absorption band where the normalized density is 0.50 from the wavelength 
of maximum absorption. 
In solution, each of the four dyes have similar LBW values. Upon 
spin-coating, the LBW values of the dyes from IC-7 and IC-35 are 32 nm and 
28 nm less than the LBW values of the same dyes in solution, respectively. 
These couplers therefore meet the criterion defined for "NB couplers". The 
spin-coating LBW values for the dyes from comparison couplers CC-1 and 
CC-2 are different from the solution LBW values by only 1 nm, and 
therefore are not "NB couplers". 
TABLE 1 
______________________________________ 
Spin Coating (SC), and acetonitrile solution (Soln.) Data (nm) 
Difference = 
LBW 
.sub.max .sub.max HBW HBW LBW LBW (Soln.) - 
Dye (Soln.) (SC) (Soln.) (SC) (Soln.) (SC) LBW (SC) 
______________________________________ 
IC-7 637 619 123 73 66 34 32 
IC-35 633 624 123 77 64 36 28 
CC-1 628 631 121 126 63 62 1 
CC-2 626 634 124 126 64 63 1 
______________________________________ 
Comparison Couplers. 
##STR14## 
EXAMPLE 2 
Dispersion Preparation 
Dispersion 1 was prepared by combining a solution of 8.4 g of Coupler IC-7, 
2.8 g of ST-1, and 11.3 g of CS1 at 130.degree. C. with an 80.degree. C. 
solution consisting of 9.0 g decalcified gelatin, 109.5 g de-mineralized 
water, and 9.0 g of a 10% solution of surfactant Alkanol XC (trademark of 
E. I. Dupont Co.). This combined solution was mixed for one minute at 8000 
rpm using a Brinkmann rotor-stator mixer, then homogenized via 2 passes 
through a Microfluidics Microfluidizer at 570 kg/cm.sup.2, 80.degree. C. 
to produce Dispersion 1. This dispersion was then placed in cold storage 
until ready for combination with a light-sensitive photographic emulsion 
in a photographic element. 
Dispersion 2 was prepared as Dispersion 1, except replacing CS-1 with S-1. 
Dispersion 3 was prepared as Dispersion 1, except that the first solution 
contained 9.0 g of Coupler IC-7, 5.4 g of CST-1, and 2.7 g of S-2, and 5.4 
g S-3 at 130.degree. C. 
Dispersion 4 was prepared as Dispersion 1, except that the first solution 
contained 8.1 g of Coupler IC-7, 4.6 g of CST-1, and 9.7 g of S-1 at 
130.degree. C. 
Dispersion 5 was prepared as Dispersion 1, except that a solution of 16.3 g 
of Coupler IC-7, 9.3 g of ST-1, and 19.5 g of S-1 at 130.degree. C. was 
combined with an 80.degree. C. solution consisting of 18.0 g decalcified 
gelatin, 219.0 g de-mineralized water, and 18.0 g of a 10% solution of 
surfactant Alkanol XC. 
Dispersion 6 was prepared as Dispersion 1, except that the first solution 
contained 5.6 g of Coupler IC-7, 4.2 g of ST-1, and 12.7 g of S-1. 
Dispersion 7 was prepared as Dispersion 6, except with 8.4 g of ST-1, and 
8.4 g of S-1. 
Dispersion 8 was prepared as Dispersion 6, except with 0 g of ST-1, and16.9 
g of S-1. 
Dispersion 9 was prepared as Dispersion 1, except that the first solution 
contained 8.1 g of Coupler IC-7, 4.6 g of ST-1, and 9.7 g of S-1. 
Dispersion 10 was prepared as Dispersion 1, except replacing solvent S-1 
with solvent S-3. 
To evaluate the effectiveness of the coupler solvent to provide dispersion 
with a minimum amount of crystalline material in each dispersion, samples 
of Dispersions 1-10 were examined via cross-polar microscopy at 98.times. 
magnification after storage of the dispersions at 5.degree. C. for 24 
hours. Polaroid photographs were taken and the number of crystals observed 
in the approximately 72 mm.times.94 mm area of the photograph were counted 
and are reported in Table 2b. 
TABLE 2a 
______________________________________ 
Dispersion descriptions 
Coupler 
Solvent 
Stabilizer 
Dispersion Solvent Stabilizer wt fraction wt fraction wt fraction 
______________________________________ 
1 CS-1 ST-1 0.375 0.500 0.125 
2 S-1 ST-1 0.375 0.500 0.125 
3 CS-2:CS-3 CST-1 0.400 0.360 0.240 
1:2 
4 S-1 CST-1 0.361 0.432 0.206 
5 S-1 ST-1 0.361 0.432 0.206 
6 S-1 ST-1 0.250 0.563 0.188 
7 S-1 ST-1 0.250 0.375 0.375 
8 S-1 -- 0.250 0.750 0.000 
9 S-1 ST-1 0.361 0.432 0.206 
10 S-3 ST-1 0.361 0.432 0.206 
______________________________________ 
TABLE 2b 
______________________________________ 
Dispersion results 
Number of 
Dispersion Crystals Comment 
______________________________________ 
1 225 Comparison 
2 125 Invention 
3 350 Comparison 
4 215 Comparison 
5 45 Invention 
6 125 Invention 
7 90 Invention 
8 60 Comparison 
9 85 Invention 
10 28 Invention 
______________________________________ 
Dispersion 1 containing comparison solvent CS-1 has a high number of 
crystals. The use of the solvent of the invention S-1 in Dispersion 2 
reduced the number of crystals. 
Dispersion 3 containing comparison solvents CS-2 and CS-3 and comparison 
stabilizer CST-1 has a high number of crystals. Use of the solvent of the 
invention with CST-1 reduces the number of crystals, as in Dispersion 4, 
but further improvement is achieved through the use of the solvent of the 
invention S-1 combined with stabilizer of the invention ST-1 as in 
Dispersions 5, 6, 7, and 9. The use of solvent S-3 with ST-1 and IC-7 also 
provided a dispersion with low crystals, as in Dispersion 10. The 
combination of the coupler of the invention and the solvent of the 
invention also provided a low crystal dispersion, as in Dispersion 9. 
Comparison Stabilizer CST-1 
##STR15## 
Comparison Solvent CS-1 
##STR16## 
Comparison Solvent CS-2 
EQU CH.sub.3 (CH.sub.2).sub.7 CH.dbd.CH(CH.sub.2).sub.8 OH 
Comparison Solvent CS-3 
##STR17## 
EXAMPLE 3 
Preparation of Photographic Elements 
Using the dispersions of Example 2, photographic elements 100 through 110 
were prepared by coating the following layers on a gel-subbed, 
polyethylene-coated paper support: 
First Layer 
An underlayer containing 3.23 grams gelatin per square meter. 
Second Layer 
A photosensitive layer containing (per square meter) 1.53 grams gelatin, an 
amount of red-sensitized silver chloride emulsion containing the silver 
necessary to coat 0.150 grams per square meter of silver, except Element 
100 which contained 0.187 grams per square meter of silver, and an amount 
of dispersion necessary to coat the amount of coupler in grams per square 
meter as specified in Table 3a. 
Third Layer 
A layer containing 1.40 grams gelatin per square meter. 
Fourth Layer 
A protective layer containing (per square meter) 1.08 grams gelatin, 0.127 
grams bis(vinylsulfonyl)methane ether, 8.83 milligrams Alkanol XC, and 
3.34 milligrams tetraethylammonium perfluorooctanesulfonate. 
Element 100 used a commercial dispersion, designated Dispersion 0, 
containing coupler CC-3, CS-1, and ST-1 in the ratio specified by Table 
3a. Elements 109-110 were prepared as elements 100-108, except that the 
second layer contained 1.66 grams gelatin per square meter. 
Comparison Coupler CC-3 
##STR18## 
Preparation of Processed Photographic Examples 
Processed samples were prepared by exposing the coatings through a step 
wedge and processing as follows: 
______________________________________ 
Process Step Time (min.) 
Temp. (.degree. C.) 
______________________________________ 
Developer 0.75 35.0 
Bleach-Fix 0.75 35.0 
Water wash 1.50 35.0 
______________________________________ 
The processing solutions used in the above process had the following 
compositions (amounts per liter of solution): 
______________________________________ 
Developer 
Triethanolamine 12.41 g 
Blankophor REU (trademark of Mobay Corp.) 2.30 g 
Lithium polystyrene sulfonate 0.09 g 
N,N-Diethylhydroxylamine 4.59 g 
Lithium sulfate 2.70 g 
Developing agent Dev-1 5.00 g 
1-Hydroxyethyl-1,1-diphosphonic acid 0.49 g 
Potassium carbonate, anhydrous 21.16 g 
Potassium chloride 1.60 g 
Potassium bromide 7.00 mg 
pH adjusted to 10.4 at 26.7.degree. C. 
Bleach-Fix 
Solution of ammonium thiosulfate 71.85 g 
Ammonium sulfite 5.10 g 
Sodium metabisulfite 10.00 g 
Acetic acid 10.20 g 
Ammonium ferric ethylenediaminetetraacetate 48.58 g 
Ethylenediaminetetraacetic acid 3.86 g 
pH adjusted to 6.7 at 26.7.degree. C. 
______________________________________ 
##STR19## 
The Status A red densities of the processed strips were read and 
sensitometric curves (density vs log exposure) were generated. The 
contrast (.gamma.) was measured by calculating the slope of the density v 
log exposure plot over the range of 0.6 log E centered on the exposure 
yielding 1.0 density. This value is reported in Table 3b. 
The spectra of the resulting dyes were measured and normalized to a maximu 
absorption of 1.00. The wavelength of maximum absorption was recorded as 
the ".lambda.max." As a measure of the sharpness of the curve on the left 
(short wavelength) side of the absorption band the "left bandwidth" (LBW) 
was obtained by subtracting the wavelength at the point on the left side 
of the absorption band where the normalized density is 0.50 from the 
.lambda.max. A lower value of LBW indicates a reduction in the unwanted 
green absorption and is thus desirable. Unwanted green absorption from 
cyan dye was also measured as the amount of density in the normalized 
spectra at 530 nm. The .lambda.max, LBW, and 530 nm density values are 
shown in Table 3b. 
TABLE 3a 
__________________________________________________________________________ 
Description of Photographic Elements for Example 3. 
Coupler 
Solvent 
Stabilizer 
Disper- Laydown Laydown Laydown 
Element sion Coupler Solvent Stabilizer (mg/m.sup.2) (mg/m.sup.2) 
(mg/m.sup.2) 
__________________________________________________________________________ 
100 0 C-1 CS-1 ST-1 423 415 272 
101 1 IC-7 CS-1 ST-1 431 574 144 
102 2 IC-7 S-1 ST-1 431 574 144 
103 3 IC-7 CS-3:CS-4 CST-1 484 436 291 
1:2 
104 4 IC-7 S-1 CST-1 415 496 237 
105 5 IC-7 S-1 ST-1 415 496 237 
106 6 IC-7 S-1 ST-1 287 647 216 
107 7 IC-7 S-1 ST-1 287 431 431 
108 8 IC-7 S-1 -- 287 861 0 
109 9 IC-7 S-1 ST-1 484 580 275 
110 10 IC-7 S-3 ST-1 484 580 275 
__________________________________________________________________________ 
TABLE 3b 
______________________________________ 
Photographic results. 
Density at 
Element .gamma. max LBW 530 nm Comment 
______________________________________ 
100 2.87 656 88 0.229 Comparison 
101 3.00 624 58 0.217 Comparison 
102 3.00 620 52 0.190 Invention 
103 2.80 626 54 0.168 Comparison 
104 2.93 624 58 0.220 Comparison 
105 2.99 624 54 0.184 Invention 
106 2.88 622 52 0.180 Invention 
107 2.89 620 46 0.166 Invention 
108 2.89 622 54 0.191 Comparison 
109 2.95 624 54 0.182 Invention 
110 2.90 626 56 0.183 Invention 
______________________________________ 
Element 100 with comparison coupler C-1 in combination with comparison 
solvent CS-1 and stabilizer ST-1 has a high LBW and high density at 530 
nm. Element 101 with the coupler of the invention with the same solvent 
and stabilizer has an improved lower LBW, but is hardly lower in density 
at 530 nm. Changing the solvent to the solvent of the invention as in 
Element 102 improved the LBW and density at 530 nm. Element 103 with 
comparison solvents CS-3 and CS-4 has low LBW and very low density at 530 
nm, but the .gamma. is reduced. Element 104 with a solvent of the 
invention resulted in higher LBW and density at 500 nm. Element 105 with 
the solvent and stabilizer of the invention are improved in LBW and 
density at 530 nm. 
Element 106 contains the stabilizer and solvent of the invention which 
gives a low density at 530 nm, and maintains good gamma at lower coupler 
laydown. Further reduction of the density at 530 nm is achieved through 
higher laydown of the stabilizer of the invention in Element 107. Complete 
removal of the ST-1, as in Element 108 does not take full advantage of the 
hue improvement associated with the combination of the invention. 
Examination of Tables 2b and 3b demonstrate that the use of the solvents 
and stabilizers of the invention with the coupler of the invention 
overcome the disadvantages of solvents previously used which do not allow 
for good dissolution of the coupler, maintenance of good reactivity, or 
minimization of the amount of unwanted green absorption of the dye formed 
from the coupler of the invention. 
The entire contents of the various patents and other publications referred 
to in this specification are incorporated herein by reference.