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Description  |
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FIELD OF THE INVENTION
This invention relates to photography, especially to dyes useful as filter
dyes in photographic elements.
BACKGROUND OF THE INVENTION
Photographic materials may utilize filter dyes for a variety of purposes.
Filter dyes may be used to adJust the speed of a radiation-sensitive
layer, they may be used as so called absorber dyes to increase image
sharpness, they may be used as antihalation dyes to reduce halation, and
they may also be used to reduce the amount or intensity of radiation or to
prevent radiation of a specific wavelength from reaching one or more of
the radiation-sensitive layers in a photographic element. For each of
these uses, the filter dye may be located in any of a number of layers of
a photographic element, depending on the specific requirements of the
element and the dye, and on the manner in which the element is to be
exposed. The amounts of filter dyes used varies widely, but they are
preferably present in amounts sufficient to alter in some way the
photographic response of the element. Filter dyes may be located in a
layer above a radiation-sensitive layer, in a radiation-sensitive layer,
below a radiation sensitive layer, or in a layer on the opposite side of
the support from a radiation-sensitive layer.
Photographic materials often contain layers sensitized to different regions
of the spectrum, such as red, blue, green, ultraviolet, infrared, X ray,
to name a few. A typical color photographic element contains a layer
sensitized to each of the three primary regions of the visible spectrum,
i.e., blue, green, and red. Silver halide used in these materials has an
intrinsic sensitivity to blue light. Increased sensitivity to blue light,
along with sensitivity to green light or red light, is imparted through
the use of various sensitizing dyes adsorbed to the silver halide grains.
Sensitized silver halide retains its intrinsic sensitivity to blue light.
If, prior to processing, blue light reaches a layer containing silver
halide that has been sensitized to a region of the spectrum other than
blue, the silver halide grains exposed to the blue light, by virtue of
their intrinsic sensitivity to blue light, would be rendered developable.
This would result in a false rendition of the image information being
recorded by the photographic element. It is therefore a common practice to
include in the photographic element a material that filters blue light.
This blue absorbing material can be located anywhere in the element where
it is desired to filter blue light. In a color photographic element that
has layers sensitized to each of the primary colors, it is common to have
the blue-sensitized layer closest to the exposure source and to interpose
a blue-absorbing, or yellow, filter layer between the blue-sensitized
layer and the green- and red-sensitized layers.
The material most commonly used as a blue-absorbing material in
photographic elements is yellow colloidal silver, referred to in the art
as Carey Lea silver. It absorbs blue light during exposure and is readily
removed during processing, usually during the silver bleaching and fixing
steps. Carey Lea silver, however, exhibits unwanted absorption in the
green region of the spectrum. Also, silver can be an expensive component
of a photographic element and can cause unwanted photographic fog.
A number of yellow dye alternatives for Carey Lea silver have been
suggested. These include dyes disclosed in U.S. Pat. Nos. 2,538,008,
2,538,009, and 4,420,555, and U.K. Pat. Nos. 695,873 and 760,739. Many of
these dyes, although they exhibit the requisite absorption of blue light,
also are subject to stain problems.
Many filter dyes (yellow dyes as well as other colors) for use in
photographic elements suffer from stain problems. Some dyes are not fully
decolorized or removed during photographic processing, thus causing post
processing stain. Other dyes wander into other layers of the element,
adversely affecting image quality. Still other dyes react before exposure
with other components of the photographic element, such as color couplers,
thus causing incubative stain. Therefore, it would be desirable to provide
a filter dye for use in photographic elements that does not suffer from
incubative or post processing stain problems.
SUMMARY OF THE INVENTION
Photographic elements according to the invention contain filter dyes of the
formula:
##STR2##
wherein R is substituted or unsubstituted alkyl or aryl, X is an electron
withdrawing group, R' is substituted or unsubstituted aryl or a
substituted or unsubstituted aromatic heterocyclic nucleus, and L, L', and
L" are each independently a substituted or unsubstituted methine group.
The dyes of formula (I) do not cause incubative stain in photographic
elements and the elements are readily decolorized during photographic
processing.
DETAILED DESCRIPTION OF THE INVENTION
According to formula (I), R is substituted or unsubstituted alkyl or aryl.
Preferred alkyl groups include alkyl of from 1 to 20 carbon atoms,
including straight chain alkyls such as methyl, ethyl, propyl, butyl,
pentyl, decyl, dodecyl, and so on, branched alkyl groups such as
isopropyl, isobutyl, t-butyl, and the like. These alkyl groups may be
substituted with any of a number of known substituents, such as sulfo,
sulfato, sulfonamide, amido, amino, carboxyl, halogen, alkoxy, hydroxy,
phenyl, and the like. The substituents may be located essentially anywhere
on the alkyl group. The possible substituents are not limited to those
exemplified, and one skilled in the art could easily choose from a number
of substituted alkyl groups that would provide useful compounds according
to formula (I).
Preferred aryl groups for R include aryl of from 6 to 10 carbon atoms
(e.g., phenyl, naphthyl), which may be substituted. Useful substituents
for the aryl group include any of a number of known substituents for aryl
groups, such as sulfo, sulfato, sulfonamido (e.g., butanesulfonamido),
amido, amino, carboxyl, halogen, alkoxy, hydroxy, acyl, phenyl, alkyl, and
the like. Additionally, the aryl group may have substituents that form
fused ring systems with it, such as naphthyl. The substituents can be
located essentially anywhere on the ring. The possible substituents are
not limited to those exemplified, and one skilled in the art could easily
choose from a number of substituted aryl groups that would provide useful
compounds according to formula (I).
X represents an electron withdrawing group. Electron withdrawing groups in
organic compounds are well-known in the art, such as described in J.
Marsh, Advanced Organic Chemistry, 3rd Ed., p. 238, the disclosure of
which is incorporated herein by reference in its entirety. Useful electron
withdrawing groups include, for example, cyano, substituted or
unsubstituted carboxylate (preferably of from 2 to 7 carbon atoms, e.g.,
CO.sub.2 R.sup.3 where R.sup.3 is substituted or unsubstituted alkyl or
aralkyl), and --CO--R" where R" is primary or secondary amino, and aryl
(either unsubstituted or substituted with an electron withdrawing group,
e.g., phenyl, p-nitrophenyl, p-cyanophenyl, 3,4-dichlorophenyl). The
possible substituents for the various X and R" groups will be known to
those skilled in the art and include those described herein for R and R'.
R' represents aryl, preferably of from 6 to 10 carbon atoms, which may be
substituted, as described above with respect to R, or a substituted or
unsubstituted aromatic heterocyclic ring, preferably a 5- or 6 -membered
ring, which may be fused with another ring system. When R' is a 6-membered
heterocyclic ring, the ring preferably contains at least one nitrogen
atom. Examples of useful aromatic heterocyclic rings include furan,
thiophene, pyridine, pyrrole, and imidazole. These rings may be
substituted as described with respect to the aryl groups. In one preferred
embodiment, R' is or is substituted with an electron donor group. Electron
donor groups for organic compounds are well-known in the art, as described
in the above-referenced Marsh, Advanced Organic Chemistry, 3rd. Ed. and
include, for example alkoxy, aryloxy, --NHCOR where R is alkyl or aryl,
--OCOR where R is alkyl or aryl, and --SR where R is alkyl or aryl.
In a preferred embodiment, R, R', or X may be substituted with at least one
solubilizing group. This enables the dyes to be solubilized and removed
and/or decolorized during processing so as to minimize dye stain caused by
residual dye. Such solubilizing groups are known in the art and include,
for example sulfonate (e.g . SO.sub.3 Na), sulfato, carboxy salts (e.g.,
CO.sub.2 Na), and the like. In an especially preferred embodiment, the
solubilizing group comprises an ionizable proton (e.g., CO.sub.2 H,
NHSO.sub.2 R where R is substituted alkyl of from 1 to 12 carbon atoms or
substituted or unsubstituted aryl of from 6 to 12 carbon atoms. Such
ionizable protons tend to cause the dyes of formula (I) to be insoluble at
acid to neutral coating pH's and soluble at neutral to basic processing
pH's. Dyes according to formula (I) comprising such ionizable protons are
well-adapted to use in photographic elements in the form of solid particle
dispersions, described below.
In a preferred embodiment of the invention, the dye of formula (I) is a
yellow filter dye where n is 0 and R' is selected from the group
consisting of furan, methylfuran, pyrrole, aryl, and thiophene.
Examples of useful dyes according to formula (I) are shown below.
##STR3##
The dyes of formula (I) can be prepared by well known chemical synthetic
techniques, such as described in U.S. Pat. No. 3,661,899. The synthesis of
dyes according to formula (I) is described below in further detail in the
Examples.
The dyes of formula (I) are useful as filter dyes for any of the purposes
and in any of the locations described above where it would be known to one
skilled in the art to use filter dyes. Such elements generally comprise a
support having thereon one or more radiation-sensitive layers, usually
silver halide layers along with a number of other layers known to those
skilled in the art, as described below.
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, N.Y. (1965). Radiation-sensitive materials exhibiting sensitivity to
blue light and especially those sensitive to blue light and at least some
other wavelength of radiation are preferred, as the dyes according to the
invention can be advantageously used to absorb some or all of the blue
light.
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, for example, 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, X-ray, 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 radiation sensitive material and the dye of formula (I) are preferably
dispersed in film forming polymeric vehicles and/or binders, as is
well-known in the art. These include both naturally occurring and
synthetic binders, such as gelatin and gelatin derivatives, polyvinyl
alcohols, acrylamide polymers, polyvinylacetals, polyacrylates, and the
like. Additional disclosure relating to useful vehicles and/or binders can
be found in Research Disclosure, Section IX. In certain instances,
especially where the dye is mobile (e.g., a dye with one or more
SO.sub.3.sup..THETA. substituents), it may be advantageous use the dye in
combination with a mordant, such as polyvinylimidazole or
polyvinylpyridine, to aid in immobilizing the dye. The technology of
mordanting dyes is well-known in the art, and is described in further
detail in Jones et al U.S. Pat. No. 3,282,699 and Heseltine et al U.S.
Pat. Nos. 3,455,693 and 3,438,779.
In many instances, it is preferable to use a dispersing aid to help
disperse the dye in the binder. Such dispersing aids are well-known in the
art and include tricresyl phosphates, n-C.sub.11 H.sub.23 CON(C.sub.2
H.sub.5).sub.2, or dibutyl phthalate. Also, in a preferred embodiment, the
dye is dispersed in the binder in the form of a solid particle dispersion,
where small solid particles of the dye (having a mean diameter on the
order of 10 .mu.m or less and preferably 1 .mu.m or less) are dispersed
throughout the binder. Such dispersions are formed either by milling the
dye in solid form until the desired particle size range is reached or by
precipitating the dye directly in the form of a solid particle dispersion.
Alternatively, the dye can be loaded into a latex polymer, either during
or after polymerization, and the latex can be dispersed in a binder.
Additional disclosure on loaded latexes can be found in Milliken U.S. Pat.
3,418,127.
The filter dye of formula (I) may be located in any of a number of layers
of a photographic element, depending on the specific requirements of the
element and the dye, and on the manner in which the element is to be
exposed. The dye may be located in a layer above the radiation-sensitive
layer, in the radiation-sensitive layer, below the radiation-sensitive
layer, or in a layer on the opposite side of the support from the
radiation-sensitive layer. The dye of formula (I) is present in a layer of
the photographic element in an amount to be effective as a photographic
filter dye, as would be known to one skilled in the art. The dye of
formula (I) is preferably present in an amount of from 1 to 2000
mg/m.sup.2 and more preferably in an amount of from 50 to 500 mg/m.sup.2.
The dye preferably provides an optical density of 0.1 to 3.0 density units
at its .lambda.-max.
In a preferred embodiment, the dye of formula (I) is a yellow filter dye. A
preferred class of yellow filter dyes are dyes according to formula (I)
where n is 0, X is cyano and R' is furan, thiophene, or pyrrole
(preferably furan). The hue of the dye can be shifted by increasing or
decreasing the charge separation between X and R' and/or by varying n.
Increasing the charge separation, either by making R' a stronger electron
donor or by making X a stronger electron acceptor or both will tend to
shift the absorption of the dye to longer wavelengths. Decreasing the
charge separation, either by making R' a weaker electron donor or by
making X a weaker electron acceptor or both will tend to shift the
absorption of the dye to shorter wavelengths. Increasing n will tend to
shift the absorption to longer wavelengths and decreasing n will tend to
shift the absorption to shorter wavelengths. Starting with the
above-defined preferred group of yellow dyes, one skilled in the art would
be able to vary X, R', and n to provide other yellow filter dyes within
the scope of formula (I).
A yellow filter dye according to formula (I) can be used in any
photographic element where it is desirable to absorb light in the blue
region of the spectrum. The dye could be used, for example, in a separate,
non-light-sensitive filter layer or as an intergrain absorber in a
radiation-sensitive layer. The dye is especially advantageously utilized
in photographic elements having at least one silver halide layer that is
sensitive to some wavelength of radiation other than blue light in
addition to its intrinsic sensitivity to blue light. In such an instance,
the dye can be used to reduce or prevent blue light from reaching this
silver halide, thus assuring that the response of the silver halide will
be to the radiation to which it is sensitized rather than from its
intrinsic sensitivity to blue light.
Although a yellow dye according to formula (I) can be utilized in any
photographic element where it is desired to absorb blue light, the dye is
especially advantageously utilized in photographic elements having at
least one silver halide layer that is sensitive to some wavelength of
radiation other than blue light, e.g., a color photographic element. Color
photographic elements 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. In such an element, the yellow
filter dye according to formula (I) would preferably be located below the
blue-sensitive layer and above the green- and red-sensitive layers. 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.
In a preferred embodiment of the invention, the dye of formula (I) is in a
layer that is positioned between two light-sensitive silver halide layers,
at least one of which is sensitive to at least one region of the spectrum
other than blue. Such an element can be, for example, a color photographic
element having a blue-sensitive layer, a green-sensitive layer, and a
red-sensitive layer. In such an element, the layer containing the dye of
formula (I), is preferably a yellow filter layer positioned between the
blue-sensitive layer and all of the green- and red-sensitive layers,
although it is possible for certain applications to have some of the red
and/or green layers closer to the blue-sensitive layer than the yellow
filter layer. One such alternative arrangement is described in U.S. Pat.
No. 4,129,446, where a yellow filter layer is positioned between pairs of
green- and red-sensitive emulsion layers so that at least some blue light
reaches the faster green- and red-sensitive layers before striking the
yellow filter layer. Other alternative arrangements are described in U.S.
Pat. Nos. 3,658,536, 3,990,898, 4,157,917, and 4,165,236.
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 0.05 density unit, and
preferably less than 0.02 density unit to the transmission 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., 9 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 Example 1 --Preparation of Dye 1
Furfural (0.48 g) was dissolved in ethanol (15 ml), and 4-(4-'butane
sulfonamido)-3-cyano-2-furanone (1.6 g) was added together with 0.5 g
sodium acetate. The mixture was heated at about 40-45.degree. C. for 2
hours and then cooled to room temperature. The solid material was filtered
off and washed with a 50/50 mixture of ethanol and water to yield 1.6 g of
Dye 1. .lambda.-max=414 nm (methanol), .epsilon.max=3.4.times.10.sup.4.
Synthesis 2 --Preparation of Dye 2
4-Butane sulfonamidobenzaldehyde (0.3 g) was dissolved in acetic acid (10
ml) and 4-(4-'butane sulfonamido)-3-cyano-2-furanone (0.4 g) was added.
The mixture was heated with a steam bath for 60 minutes after addition of
sodium acetate (0.25 g) and allowed to cool. The mixture was then poured
into water, stirred for 60 minutes, and the yellow-brown solid that formed
was filtered off, washed with water, dried, and recrystallized from
methanol to yield Dye 2. .lambda.-max=406 (methanol),
.epsilon.-max=3.59.times.10.sup.4.
EXAMPLE 1
A solid particle dispersion of Dye 1 was prepared according to the
following technique. 1.0 g of the dye was placed in a 60 ml screw-capped
bottle along with 21.7 ml water, 2.65 g Triton X-200.degree. surfactant
(Rohm & Haas), and 40 ml of 2 mm diameter zirconium oxide beads. The
bottle was capped and the contents milled for four days. The container was
removed and the contents added to a 12.5% aqueous gelatin (8.0 g)
solution. This mixture was placed on a roller mill for 10 minutes to
reduce foaming and the resulting mixture was filtered to remove the
zirconium oxide beads.
The above-described solid particle dispersion was coated as a yellow filter
dye in a color photographic element having the following format (coverages
in parentheses):
______________________________________
Bis-vinylsulfonyl methyl ether
(1.55% of total gel)
Gelatin (980 mg/m.sup.2)
Gelatin and ultraviolet filter
(1786 mg/m.sup.2)
AgBrI (6.4% I) (1.8.mu. and 0.65.mu.)
(1561 mg/m.sup.2)
Sensitizing Dye SD-1 (458 mg/mole Ag)
Yellow Dye-Forming Coupler C-1
(1819 mg/m.sup.2)
Gelatin (2852 mg/m.sup.2)
Gelatin (1076 mg/m.sup.2)
Dye 1 (344 mg/m.sup.2)
AgBrI (6.4% I) (0.9.mu.)
(883 mg/m.sup.2)
Sensitizing Dye SD-2 (192 mg/mole Ag)
Sensitizing Dye SD-3 (66 mg/mole Ag)
Magenta Dye-Forming Coupler C-2
(699 mg/m.sup.2)
Gelatin (1399 mg/m.sup.2)
AgBrI (6.4% I) (0.8.mu. and 0.5.mu.)
(825 mg/m.sup.2)
Sensitizing Dye SD-2 (244 mg/mole Ag)
Sensitizing Dye SD-3 (84 mg/mole Ag)
Magenta Dye-Forming Coupler C-2
(250 mg/m.sup.2)
Gelatin (2110 mg/m.sup.2)
Gelatin (1076 mg/m.sup.2)
AgBrI (6.4% I) (0.9.mu.)
(63.5 mg/m.sup.2)
Sensitizing Dye SD-4 (174 mg/mole Ag)
Sensitizing Dye SD-5 (17 mg/mole Ag)
Cyan Dye-Forming Coupler C-3
(527 mg/m.sup.2)
Gelatin (1270 mg/m.sup.2)
AgBrI (6.4% I) (0.8.mu.)
(678 mg/m.sup.2)
Sensitizing Dye SD-4 (192 mg/mole Ag)
Sensitizing Dye SD-5 (19 mg/mole Ag)
Cyan Dye-Forming Coupler C-3
(222 mg/m.sup.2)
Gelatin (1066 mg/m.sup.2)
AgBrI (6.4% I) (0.5.mu.)
(844 mg/m.sup.2)
Sensitizing Dye SD-4 (262 mg/mole Ag)
Sensitizing Dye SD-5 (26 mg/mole Ag)
Cyan Dye-Forming Coupler C-3
(273 mg/m.sup.2)
Gelatin (1152 mg/m.sup.2)
______________________________________
Support
##STR4## SD-1
##STR5## SD-2
##STR6## SD-3
##STR7## SD-4
##STR8## SD-5
##STR9## C-1
##STR10## C-2
##STR11## C-3
______________________________________
For comparison, identical elements were prepared except that in place of
Dye 1 were used Carey Lea silver or a comparison mordanted soluble dye
having the formula:
##STR12##
at levels to give equivalent filtering of blue light in their respective
elements as that of Dye 1 in the element of the invention. As a control in
order to show the effects of the presence of the filter dyes or Carey Lea
silver on the element, identical elements were prepared containing neither
a yellow filter dye nor Carey Lea silver. The elements were exposed to a
test image, processed using Kodak E-6.RTM. processing, and the speed and
blue layer fog were determined. Kodak E-6.RTM. processing is described in
British Journal of Photography Annual, 1977, pp. 194-97. The results are
presented in Table I.
TABLE I
______________________________________
Change in Change in Change in
Relative Relative Relative
Red Speed Green Speed
Blue Speed
at Optical at Optical at Optical
Change
Density of Density of Density of
in Fog
1.0 Compared
1.0 Compared
1.0 Compared
Compared
Filter
to Control to Control to Control
to Control
Dye Red Speed Green Speed
Blue Speed
Fog
______________________________________
1 -18 -15 -38 -0.01
Com- -13 -33 -72 -0.06
parison
Dye
Carey -20 -47 -47 +0.45
Lea
Silver
______________________________________
As shown in Table I, the use of a dye of formula (I) as a yellow filter dye
in a photographic element caused smaller losses in green and blue speeds
than either the comparison dye or Carey Lea silver while exhibiting
similar performance as the comparisons with respect to red speed. Also,
the dye of formula (I) contributed no additional fog compared to
significant fog from Carey Lea silver.
Examples 2-11 --Spectral Absorption and Bleachability
Dyes according to formula (I) were coated on supports as dispersions in
gelatin using high-boiling water-insoluble solvents such as tri-cresyl
phosphates and/or N,N-diethyl-dodecanamide, and the spectral absorbance
was recorded. The elements were then subjected to a 5-minute distilled
water wash and the spectrum was remeasured to evaluate dye wandering
characteristics at low pH. The elements were also processed for 6 minutes
in each of the two Kodak E-6.degree. developers at 38.degree. C.,
followed by 1 minute in a 1% CH.sub.2 O solution, after which spectral
absorbance was recorded again. The results are reported in Table II.
TABLE II
______________________________________
OD at .lambda.-max
Before
Wash After After
Level .lambda.-max
or Water Processing
Dye (g/m.sup.2)
(nm) Processing
Wash (400-700 nm)
______________________________________
1 0.13 422 0.98 0.99 0.01
2 0.14 416 0.96 * 0.01
3 0.14 483 1.21 1.14 0.01
5 0.14 444 0.97 0.96 0.01
6 0.12 420 0.67 0.66 0.01
7 0.14 422 0.70 0.72 0.01
9 0.19 420 1.17 1.17 0.02
10 0.19 419 0.95 * 0.01
11 0.14 417 0.68 0.65 0.01
12 0.16 418 0.62 * 0.01
______________________________________
*Dyes 2, 10, and 12 exhibit little or no density loss during water wash,
but optical densities were not recorded.
The results in Table II indicate that the dyes according to the invention
are effective as filter dyes in the gelatin layers utilized in
photographic elements, and are removed and/or decolorized ion during
photographic processing.
This invention has been described in detail with particular 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.
* * * * *
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