Solid particle dispersions of filter dyes for photographic elements

Solid particle dispersions of dyes according to the formula: ##STR1## wherein D is selected from the group consisting of ##STR2## are disclosed as filter dyes for photographic elements. In this formula, R.sup.1, R.sup.2, and R.sup.3 are each independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted alkoxy. At least one of R.sup.1, R.sup.2 and R.sup.3 is substituted or unsubstituted alkoxy, or two of R.sup.1, R.sup.2 and R.sup.3 together consist of --O--L--O-- and form a ring condensed with the phenyl ring to which they are attached wherein L is an alkylene linking group. R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are each independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl. R is a carboxy or sulfonamido substituent, and L.sup.1, L.sup.2 and L.sup.3 are each independently substituted or unsubstituted methine groups. The dyes of the invention are particularly useful as filter dyes for light in the ultraviolet and short blue wavelength regions of the spectrum.

This invention relates to dyes, particularly dyes useful as filter dyes, 
especially ultraviolet/short blue filter dyes in photographic elements. 
Photographic materials often contain filter dyes to absorb light from 
different regions of the spectrum, such as red, blue, green, ultraviolet, 
and infrared, to name a few. These filter dyes are often required to 
perform the function of absorbing light during exposure of the material so 
as to prevent or at least inhibit light of a region of the spectrum from 
reaching at least one of the radiation-sensitive layers of the element. 
Ultraviolet light absorbing filter dyes also help prevent exposure from 
static emissions which may occur during manufacturing and processing. 
After processing of the element, however, the continued presence of colored 
filter dye may adversely affect the image quality of the photographic 
material. It is therefore desirable in many systems to use filter dyes 
that will be solubilized and removed or at least decolorized during 
photographic processing. Dyes that are easily solubilized, however, tend 
to wander throughout the photographic material during coating, adversely 
affecting the final image quality. While essentially colorless ultraviolet 
absorbing filter dyes are frequently retained in color photographic 
materials in order to stabilize image dyes, process removable 
ultraviolet/short blue filter dyes are desirable for many other 
applications, such as for use in the graphic arts materials described in 
U.S. Pat. No. 4,904,565 of Schmidt et al. 
To prevent dye wandering, the dyes are often coated with a mordant to bind 
the dye in the layer in which it is coated. Dye mordants, while often 
useful, tend to either bind the dye too strongly, inhibiting 
solubilization of the dye during photographic processing, or too weakly, 
thus not preventing dye wandering. It has been especially difficult to 
find non-staining and non-wandering filter dyes which absorb light in the 
ultraviolet to short blue wavelength region of the spectrum. 
It would therefore be highly desirable to provide an ultraviolet/short blue 
wavelength filter dye for use in photographic elements that does not 
wander during coating without requiring a mordant, and which is fully 
solubilized during processing for decolorizing and/or removal. 
U.S. Pat. Nos. 4,950,586, 4,948,718, 4,948,717, 4,940,654, 4,923,788, 
4,900,653, 4,861,700, 4,857,446, 4,855,221, 4,770,984 and 4,311,787 
disclose the use of various dyes in solid particle dispersions. These 
patents disclose that the use of solid particle dye dispersions allows for 
the coating of filter dyes which are immobile in coated acidic emulsion 
layers yet which can be fully removed during basic aqueous film or paper 
processing. None of these references, however, disclose the specific dyes 
of the present invention. 
U.S. Pat. Nos. 4,770,984 and 4,311,787 disclose hydroxyarylidene pyrazolone 
dyes similar to those of the present invention. These hydroxy-substituted 
dyes, however, are not as resistant to diffusion during coating operations 
and subsequent layer to layer migration as is desired. 
According to the invention, there is provided a photographic element having 
a layer comprising a hydrophilic binder and, as a filter dye, a solid 
particle dispersion of a compound having the formula: 
##STR3## 
wherein: D is selected from the group consisting of 
##STR4## 
wherein R.sup.1, R.sup.2, and R.sup.3 are each independently hydrogen, 
substituted or unsubstituted alkyl, or substituted or unsubstituted 
alkoxy, at least one of R.sup.1, R.sup.2 and R.sup.3 being substituted or 
unsubstituted alkoxy or two of R.sup.1, R.sup.2 and R.sup.3 together 
consisting of --O--L--O-- and forming a ring condensed with the phenyl 
ring to which they are attached wherein L is an alkylene linking group; 
R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are each independently hydrogen, 
substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; 
R is a carboxy or sulfonamido substituent; and 
L.sup.1, L.sup.2, and L.sup.3 are each independently substituted or 
unsubstituted methine groups. 
Solid particle dispersions of the compound of formula (I) are useful as 
filter dyes, alone or in combination with other filter dyes in 
photographic elements. They are insoluble at coating pH's of 6 or less 
(generally 4 to 6) and soluble at processing pH's of 8 or more (generally 
8 to 12), so that they do not interact with other components of the 
photographic element, yet still are fully solubilized during photographic 
processing. The non-hydroxy substituted arylidene pyrazolone dyes of the 
invention are substantially more resistant to diffusion than the 
hydroxyarylidene pyrazolone dyes of U.S. Pat Nos. 4,770,984 and 4,311,787. 
A particular advantage of benzoylacetonitrile arylidene dyes of the 
invention is that when in the form of solid particle dispersions, in 
addition to excellent coating layer specificity, they demonstrate very low 
light filtration at wavelengths beyond 450 nm, with simultaneous high 
light filtration in the 350-400 nm region, making them especially 
effective filter dyes for light at ultraviolet and short blue wavelength 
regions of the spectrum. 
R.sup.1, R.sup.2, R.sup.3 can each be hydrogen or substituted or 
unsubstituted alkyl or alkoxy, preferably of from 1 to 6 carbon atoms. At 
least one of R.sup.1, R.sup.2 and R.sup.3 is substituted or unsubstituted 
alkoxy, or two of R.sup.1, R.sup.2 and R.sup.3 together consist of 
--O--L--O-- and form a ring condensed with the phenyl ring to which they 
are attached where L is an alkylene linking group, preferably of from 1 to 
6 carbon atoms. The alkyl or alkoxy groups may be substituted with any of 
a number of substituents as is known in the art, other than those, such as 
sulfo substituents, that would tend to increase the solubility of the dye 
so much as to cause it to become soluble at coating pH's. Examples of 
useful substituents include halogen, alkoxy, ester groups, amido, acyl, 
alkylamino, carboxy, and sulfonamido. Examples of alkyl groups include 
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl, 
and isohexyl. Examples of alkoxy groups include methoxy, ethoxy, and 
propoxy. In a preferred embodiment, R.sup.1, R.sup.2, and R.sup.3 are each 
either hydrogen or alkoxy. 
R.sup.4, R.sup.5, R.sup.6, R.sup.7 can be hydrogen, substituted or 
unsubstituted alkyl, or substituted or unsubstituted aryl. Preferably, 
these groups are each independently substituted or unsubstituted alkyl of 
1 to 6 carbon atoms or substituted or unsubstituted aryl of 6 to 14 carbon 
atoms. The alkyl or aryl group may be substituted with any of a number of 
substituents other than those that would tend to increase the solubility 
of the dye so much as to cause it to become soluble at coating pH's as 
discussed for R.sup.1 -R.sup.3 above. Examples of alkyl groups include 
those set forth for R.sup.1 -R.sup.3 above. Examples of aryl groups 
include phenyl, tolyl, naphthyl, anthracenyl, pyridyl, and styryl. 
L.sup.1, L.sup.2, and L.sup.3 are substituted or unsubstituted methine 
groups, e.g. --CR.sup.8 .dbd. groups, where R.sup.8 represents hydrogen or 
substituted or unsubstituted alkyl or substituted or unsubstituted aryl as 
described above for R.sup.4 --R.sup.7. 
Dyes of formula I include at least one carboxy or sulfonamido substituent 
R. Carboxy groups have the formula CO.sub.2 H and sulfonamido groups have 
the formula NHSO.sub.2 R.sup.9 where R.sup.9 is substituted or 
unsubstituted alkyl or substituted or unsubstituted aryl as described 
above for R.sup.4 -R.sup.7. 
Examples of dyes according to formula (I) include the following: 
__________________________________________________________________________ 
1) 
##STR5## Solution (MeOH) .lambda.max 352 nm 
Solid particle dispersion (S.P.D.) 
.lambda.max 391 nm .epsilon. = 3.01 
.times. 10.sup.4 
2) 
##STR6## Solution (MeOH) .lambda.max 360 nm 
S.P.D. .lambda.max 344 nm .epsilon. = 
1.88 .times. 10.sup.4 
3) 
##STR7## Solution (MeOH + Et.sub.3 N) 
.lambda.max 352 nm S.P.D. .lambda.max 
359 nm .epsilon. = 2.46 .times. 
10.sup.4 
4) 
##STR8## Solution (MeOH + Et.sub.3 N) 
.lambda.max 363 nm S.P.D. .lambda.max 
359 nm .epsilon. = 2.83 .times. 
10.sup.4 
5) 
##STR9## Solution (MeOH) .lambda.max 372 nm 
S.P.D. .lambda.max 445 nm .epsilon. = 
2.16 .times. 10.sup.4 
6) 
##STR10## Solution (MeOH) .lambda.max 370 nm 
S.P.D. .lambda.max 379 nm .epsilon. = 
2.31 .times. 10.sup.4 
7) 
##STR11## Solution (MeOH) .lambda.max 389 nm 
S.P.D. .lambda.max 389 nm .epsilon. = 
2.0 .times. 10.sup.4 
8) 
##STR12## Solution (MeOH + Et.sub.3 N) 
.lambda.max 404 nm S.P.D. .lambda.max 
398 nm .epsilon. = 2.83 .times. 
10.sup.4 
__________________________________________________________________________ 
The dyes of formula (I) can be prepared by synthetic techniques well-known 
in the art, as illustrated by the synthetic examples below. Such 
techniques are further illustrated, for example, in "The Cyanine Dyes and 
Related Compounds", Frances Hamer, Interscience Publishers, 1964. 
The dyes of formula (I) may be incorporated in a hydrophilic layer of a 
photographic element in any known way (e.g., with the aid of a 
high-boiling non-polar organic solvent), but are preferably in the form of 
a solid particle dispersion (i.e., the dye is in the form of solid 
particles of microscopic size) for incorporation into a layer such as a 
hydrophilic colloid layer of a photographic element. The solid particle 
dispersion can be formed by precipitating the dye in the form of a 
dispersion and/or by well-known milling techniques, e.g., ball-milling, 
sand-milling, or colloid-milling (preferably ball-milling or sand-milling) 
the dye in the presence of a dispersing agent. The dispersion of dye 
particles should have a mean diameter of less than 10 .mu.m and preferably 
less than 1 .mu.m. The dye particles can be prepared in sizes ranging down 
to about 0.01 .mu.m. 
The dyes may be located in any layer of the element where it is desirable 
to absorb light, but it is particularly advantageous to locate them in a 
layer where they will be solubilized and washed out during processing. 
Particularly preferred locations include layers above light sensitive 
layers and on the backside of a clear support. Useful amounts of dye range 
from 1 to 1000 mg/m.sup.2. The dye should be present in an amount 
sufficient to yield an optical density at the absorbance D-max before 
processing of at least 0.10 density units and preferably at least about 
0.50 density units. This optical density will generally be less than 5.0 
density units for most photographic applications. 
The hydrophilic binder used in the present invention can be any known type, 
such as a hydrophilic colloid (e.g., gelatin), polyvinyl alcohol, and the 
like, as are well-known in the art. 
The support of the element of the invention can be any of a number of 
well-known supports for photographic elements. These include polymeric 
films such as cellulose esters (e.g., cellulose triacetate and diacetate) 
and polyesters of dibasic aromatic carboxylic acids with divalent alcohols 
(e.g., poly(ethylene terephthalate)), paper, and polymer-coated paper. 
Such supports are described in further detail in Research Disclosure, 
December, 1978, Item 17643 [hereinafter referred to as Research 
Disclosure], Section XVII. 
The radiation-sensitive layer of the element of the invention can contain 
any of the known radiation-sensitive materials, such as silver halide, 
diazo image-forming systems, light-sensitive tellurium-containing 
compounds, light-sensitive cobalt-containing compounds, and others 
described in, for example, J. Kosar, Light-Sensitive Systems: Chemistry 
and Application of Nonsilver Halide Photographic Processes, J. Wiley & 
Sons, New York (1965). 
Silver halide is especially preferred as a radiation-sensitive material. 
Silver halide emulsions can contain, for example, silver bromide, silver 
chloride, silver iodide, silver chlorobromide, silver chloroiodide, silver 
bromoiodide, or mixtures thereof. The emulsions can include coarse, 
medium, or fine silver halide grains bounded by 100, 111, or 110 crystal 
planes. Silver halide emulsions and their preparation are further 
described in Research Disclosure, Section I. Also useful are tabular grain 
silver halide emulsions, as described in Research Disclosure, January, 
1983, Item 22534 and U.S. Pat. No. 4,425,426. 
The radiation-sensitive materials described above can be sensitized to a 
particular wavelength range of radiation, such as the red, blue, or green 
portions of the visible spectrum, or to other wavelength ranges, such as 
ultraviolet, infrared, and the like. Sensitization of silver halide can be 
accomplished with chemical sensitizers such as gold compounds, iridium 
compounds, or other group VIII metal compounds, or with spectral 
sensitizing dyes such as cyanine dyes, merocyanine dyes, styryls, or other 
known spectral sensitizers. Additional information on sensitization of 
silver halide is described in Research Disclosure, Sections I-IV. 
The dyes of the invention can be used as interlayer dyes, trimmer dyes, 
pelloid dyes, or antihalation dyes. They can be used to prevent crossover 
in X-ray materials as disclosed in U.S. Pat. Nos. 4,900,652 and 4,803,150 
and European Patent Application Publication No. 0 391 405, to prevent 
unwanted light from reaching a sensitive emulsion layer of a multicolor 
photographic element as disclosed in U.S. Pat. No. 4,988,611, and for 
other uses as indicated by the absorbance spectrum of the particular dye. 
The dyes can be used in a separate filter layer or as an intergrain 
absorber. 
Multicolor photographic elements according to the invention generally 
comprise a blue-sensitive silver halide layer having a yellow 
color-forming coupler associated therewith, a green-sensitive layer having 
a magenta color-forming coupler associated therewith, and a red-sensitive 
silver halide layer having a cyan color-forming coupler associated 
therewith. Color photographic elements and color-forming couplers are 
well-known in the art and are further described in Research Disclosure, 
Section VII. 
The element of the invention can also include any of a number of other 
well-known additives and layers, as described in Research Disclosure. 
These include, for example, optical brighteners, antifoggants, image 
stabilizers, light-absorbing materials such as filter layers or intergrain 
absorbers, light-scattering materials, gelatin hardeners, coating aids and 
various surfactants, overcoat layers, interlayers and barrier layers, 
antistatic layers, plasticizers and lubricants, matting agents, 
development inhibitor-releasing couplers, bleach accelerator-releasing 
couplers, and other additives and layers known in the art. 
The dye of formula (I) can be located in any layer of a photographic 
element where it is desired to absorb light. In a preferred embodiment, 
the dye is preferably located in a layer where it will be subjected to 
high pH (i.e., 8 to 12) and/or sulfite during photographic processing, so 
as to allow the dye to be solubilized and removed or decolorized. 
The photographic elements of the invention, when exposed, can be processed 
to yield an image. During processing, the dye of formula (I) will 
generally be decolorized and/or removed. Following processing, the dye of 
the invention should contribute less than 0.10 density unit, and 
preferably less than 0.02 density unit to the absorbance D-max in the 
visible region in the minimum density areas of the exposed and processed 
element. 
Processing can be by any type of known photographic processing, as 
described in Research Disclosure, Sections XIX-XXIV, although it 
preferably includes a high pH (i.e., 8 or above) step utilizing an aqueous 
sulfite solution in order to maximize decolorization and removal of the 
dye. A negative image can be developed by color development with a 
chromogenic developing agent followed by bleaching and fixing. A positive 
image can be developed by first developing with a non-chromogenic 
developer, then uniformly fogging the element, and then developing with a 
chromogenic developer. If the material does not contain a color-forming 
coupler compound, dye images can be produced by incorporating a coupler in 
the developer solutions. 
Bleaching and fixing can be performed with any of the materials known to be 
used for that purpose. Bleach baths generally comprise an aqueous solution 
of an oxidizing agent such as water soluble salts and complexes of iron 
(III) (e.g., potassium ferricyanide, ferric chloride, ammonium of 
potassium salts of ferric ethylenediaminetetraacetic acid), water-soluble 
persulfates (e.g., potassium, sodium, or ammonium persulfate), 
water-soluble dichromates (e.g., potassium, sodium, and lithium 
dichromate), and the like. Fixing baths generally comprise an aqueous 
solution of compounds that form soluble salts with silver ions, such as 
sodium thiosulfate, ammonium thiosulfate, potassium thiocyanate, sodium 
thiocyanate, thiourea, and the like.

The invention is further illustrated by the following Examples. 
Synthesis of Dye 1: 
A slurry of 4.76 grams (0.02 mol) 4-methylsulfonamidobenzoylacetonitrile, 
2.44 ml (0.02 mol) 4-methoxybenzaldehyde and 15 ml of glacial acetic acid 
was heated to reflux with constant stirring. The reaction was held at 
reflux for three hours and then stirred at room temperature for sixteen 
hours. The precipitated product was collected and washed sequentially with 
isopropyl alcohol and ligroin to give 6.05 grams (84.8% yield) of crude 
dye 1. The product was purified by sequential recrystallizations from 
refluxing glacial acetic acid and xylene. The weight of dried product was 
3.29 grams (46.1% yield) of pure dye 1 as bright yellow needles, 
m.p.=169.degree.-171.degree. C. All analytical data were consistent with 
the structure. 
Synthesis of Dye 4: 
A slurry of 4.36 grams (0.02 mol) 
1-(4-carboxyphenyl)-3-methyl-2-pyrazolin-5-one, 2.6 ml (0.021 mol) 
4-methoxybenzaldehyde and 20 ml of glacial acetic acid was heated at 
reflux for 3 hours. The reaction was then cooled to room temperature and 
the precipitated product was collected by filtration to afford 7.23 grams 
(100% yield) of crude dye 4. The dye was purified by slurrying in 200 ml 
of refluxing glacial acetic acid and collection of insoluble product from 
the hot solution by filtration. The collected product was dried to give 
5.93 grams (88.1% yield) of pure dye 4, m.p.=279.degree.-281.degree. C. 
All analytical data were consistent with the structure. 
Synthesis of Dye 5: 
A mixture of 4.0 grams (0.015 mol) 
1-(4-methylsulfonamidophenyl)-3-methyl-2-pyrazolin-5-one, 2.94 grams 
(0.015 mol) 3,4,5-trimethoxybenzaldehyde, and 70 ml of butyronitrile was 
heated to reflux and stirred for one hour. The red solution was then 
cooled to room temperature and stirred for one hour. The precipitated 
orange crystals were collected by filtration and washed with ligroin to 
give 5.26 grams (78.7% yield) of crude dye 5. The dye was purified by 
recrystallization from 90 ml of refluxing glacial acetic acid and 
subsequent slurrying in 70 ml of refluxing xylene. The precipitated pure 
dye 5 was dried to give 3.26 grams (48.7% yield), 
m.p.=197.degree.-200.degree. C. All analytical data were consistent with 
the structure. 
Synthesis of Dye 8: 
A slurry of 5.2 grams (0.02 mol) 5-carboxy-3-ethoxycarbonyl-1,3-indandione, 
3.3 grams (0.22 mol) piperonal, and 100 ml of glacial acetic acid was 
heated to reflux and held at reflux for 30 minutes. After 10 minutes 
heating the reaction was fully homogeneous, and gradually a yellow-tan 
precipitate formed. After slowly cooling to room temperature the 
precipitated product was collected, washed with ethyl acetate, and dried 
to give 4.3 grams (66.7% yield) of pure dye 8, 
m.p.=284.degree.-287.degree. C. All analytical data were consistent with 
the dye structure. 
Dye Wandering and Stain Evaluation Example: 
Dyes according to formula (I) were prepared as solid particle dispersions 
by ball-milling according to the following procedure. Water (21.7 ml) and 
a 6.7% solution of Triton X-200.RTM. surfactant (2.65 g) were placed in a 
60 ml screw-capped bottle. A 1.00 g sample of dye was added to this 
solution. Zirconium oxide beads (40 ml, 2 mm diameter) were added and the 
container with the cap tightly secured was placed in a mill and the 
contents milled for four days. The container was removed and tile contents 
added to a 12.5% aqueous gelatin (8.0 g) solution. The resulting mixture 
was filtered to remove the zirconium oxide beads. The resulting dye 
dispersion had a particle size mean diameter less than 1.0 .mu.m. 
The solid particle dispersions of these dyes were coated on a polyester 
support according to the following procedure. A spreading agent 
(surfactant 10G.RTM.) and a-hardener (bis(vinylsulfonylmethyl ether) were 
added to the dye-gelatin melt prepared as described above. A melt from 
this mixture was then coated on a poly(ethylene terephthalate) support to 
achieve a dye coverage of 0.27 g/m.sup.2, a gelatin coverage of 1.61 
g/m.sup.2, a spreading agent level of 0.097 g/m.sup.2, and a hardener 
level of 0.016 g/m.sup.2. The absorbance of the dye dispersion was 
measured with a spectrophotometer. Identical elements were subjected to a 
5 minute distilled water wash (2-3 gal/min flow rate), and to Kodak 
E-6.RTM. Processing (which is described in British Journal of Photography 
Annual, 1977, pp. 194-97) and the absorbance was measured for each. The 
results are shown in Table I. 
TABLE I 
______________________________________ 
D-max after 
D-max after 
DYE .lambda.-max 
D-max Water Wash 
E-6 .RTM. Processing 
______________________________________ 
1 391 nm 0.745 0.739 0.007 
4 359 nm 0.689 0.685 0.007 
5 445 nm 0.885 0.890 0.007 
8 398 nm 0.848 0.808 0.007 
______________________________________ 
Solid particle dispersions of comparison hydroxyarylidene pyrazolone dyes 
C1, C2, and C3 illustrated below were prepared and coated on supports 
analogously to the dyes of the invention, and subjected to the same 5 
minute distilled water wash. Table II sets forth the percent loss in 
optical density (O.D.) for the comparison arylidene pyrazolone dyes and 
the non-hydroxy substituted arylidene pyrazolone dyes 4 and 5 of the 
invention. 
##STR13## 
TABLE II 
______________________________________ 
D-max after 
DYE .lambda.-max 
D-max Water Wash 
% O.D. Loss 
______________________________________ 
4 359 nm 0.689 0.685 0.5% 
5 445 nm 0.885 0.890 0.0% 
C1 376 nm 1.244 1.188 4.7% 
C2 354 nm 0.936 0.870 7.0% 
C3 358 nm 1.011 0.984 2.9% 
______________________________________ 
These results show that the dyes of formula (I) are not significantly 
affected by the water wash, indicating little wandering at coating pH, but 
are fully solubilized for removal and/or decolorization during 
photographic processing. The optical density for the non-hydroxy 
substituted alkoxyarylidene dyes of the invention was substantially less 
affected by the water wash than the hydroxyarylidene comparison dyes, 
indicating that the dyes of the invention are substantially more resistent 
to diffusion. 
The invention has been described in detail with reference to preferred 
embodiments thereof. It should be understood, however, that variations and 
modifications can be made within the spirit and scope of the invention.