[0001] This invention relates to photography and more particularly to a photographic recording
material containing a magenta dye forming coupler.
[0002] Various types of magenta dye forming couplers are known. One type, examples of which
are disclosed in U. S. Patents 3.725,067 and 4,443,536 and in U. K. Patents 1,247,493;
1,252,418 and 1,253,933, includes pyrazolotriazoles which can comprise various substituents,
including ballast groups. While such couplers generally provide highly desired photographic
results, it has been observed that some pyrazolotriazole couplers have an inhibiting
effect upon silver halide development in photographic emulsions, thereby reducing
speed and contrast of resulting dye images.
[0003] Accordingly, there is a need to provide a photographic recording material which overcomes
the problem of silver halide development inhibition without causing adverse results
in photographic properties.
[0004] We have found that certain hydrolyzable chalcogenazolium salts which comprise particular
quaternized substituents are capable of overcoming silver halide development inhibition
caused by the pyrazolotriazole couplers.
[0005] The present invention provides a photographic recording material comprising a support
having thereon a photographic silver halide emulsion layer and a pyrazolotriazole
magenta coupler which inhibits silver halide development, said recording material
being characterized in that it comprises a hydrolyzable chalcogenazolium salt of a
middle chalcogen which salt comprises a quaternized substituent having a carbon chain
interrupted by a divalent group which has the structural formula I:

wherein:
L is a divalent linking group;
T is carbonyl or sulfonyl;
T' is independently in each occurrence carbonyl or sulfonyl;
R1 is a hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
[0007] The quaternized chalcogenazolium salts, which have been found to be effective in
reducing silver halide development inhibition caused by particular pyrazolotriazole
coupler compounds, are disclosed in U. S. Patent 4,578,348. These salts are capable
of undergoing hydrolysis which opens the chalcogenazolium ring between the 2 and 3
positions thereof, that is between the ring chalcogen atom and the carbon atom which
lies mediate the ring chalcogen atom and the nitrogen atom. As hydrolyzed, these salts
demonstrate the ability to suppress silver halide development inhibition caused by
the described couplers.
[0008] As a specific illustration, compounds of the following formula II, when hydrolyzed,
can be employed as agents to overcome silver halide development inhibition caused
by particular pyrazolotriazole couplers:

wherein:
R2 and R3 are independently hydrogen; halogen; aliphatic or aromatic hydrocarbon moiety optionally
linked through a divalent oxygen or sulfur atom; cyano; amino; amido; sulfonamido;
sulfamoyl; ureido; thioureido; hydroxy; -COM or -S(SO)2M group, wherein M is chosen to complete an aldehyde, ketone, acid, ester, thioester,
amide, or salt; or R2 and R3 together can represent the atoms which complete a fused ring;
R4 is hydrogen, alkyl of from 1 to about 8 carbon atoms or aryl of from 6 to about 10
carbon atoms;
Q represents a quaternized substituent;
X is a middle chalcogen atom;
Y represents a charge balancing counter ion; and
n is 0 or 1.
[0009] Preparation of the quaternized chalcogenazolium salts described above is disclosed
in U. S. Patent 4,578,348, the disclosure of which is herewith incorporated by reference.
[0010] Where R
4 is hydrogen, ring opening occurs spontaneously after incorporating the chalcogenazolium
salt of the above formula in a silver halide emulsion. When the pH of a silver halide
emulsion is too low for ring opening hydrolysis, treatment with a base, such as an
aqueous alkaline solution of an alkali or an alkaline earth metal, or ammonium hydroxide,
can be employed prior to incorporation in a silver halide emulsion.
[0011] Whether prehydrolyzed or spontaneously hydrolyzed in situ, the salts which overcome
silver halide development inhibition caused by particular pyrazolotriazole couplers,
and which can be derived by hydrolysis of the compounds of formula (II) are represented
by formula (III):

wherein:
and R2, R3, R4, Q, X, Y and n are as previously defined.
[0012] In a specifically preferred form the quaternized substituent Q, can take the form
represented by formula (IV):

wherein:
L represents a divalent linking group, such as an optionally substituted divalent
hydrocarbon group;
T is carbonyl or sulfony;
T is independently in each occurrence carbonyl or sulfonyl;
R' represents an optionally substituted hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
[0013] In a preferred embodiment of the invention T is carbonyl and T' is sulfonyl. However,
either or both of T and T can be either carbonyl or sulfonyl. Further, where m is
greater than 1, T can in each occurrence be carbonyl or sulfonyl independently of
other occurrences,
L is preferably an alkylene (i.e., alkanediyl) group of from 1 to about 8 carbon atoms.
In specifically preferred forms of the invention L is either methylene or ethylene.
R1 is preferably a primary or secondary amino group, an alkyl group of from 1 to about
8 carbon atoms (e.g., methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, t-butyl,
neopentyl, or n-octyl), or an aryl group of from 6 to about 10 carbon atoms (e.g.,
phenyl or naphthyl). When R' completes a secondary amine, it can be substituted with
an optionally substituted hydrocarbon residue, preferably an alkyl group of from 1
to about 8 carbon atoms or an aryl group of 6 to about 10 carbon atoms, as above described.
It is also recognized that R1 can be chosen, if desired, to complete a bis compound. For example, R' can take a
form similar to L and the hydrolyzed chalcogenazolium ring linked to L, thereby incorporating
a second hydroylzed chalcogenazolium ring into the compound capable of overcoming
development inhibition.
[0014] In the above formula (IV), m is preferably 1.
[0015] Although preferred values of R
4 are described above in connection with formulae (II) and (III), it is appreciated
that R
4 can take the form of any other substituent that is compatible with ring opening hydrolysis
of the chalcogenazolium salt in the manner indicated. In general, the simpler the
form of R
4, the more easily hydrolysis is accomplished. It is specifically recognized that R
4 can embrace substituents that do not permit spontaneous hydrolysis of quaternized
chalcogenazolium salts in silver halide emulsion coatings.
[0016] X, R
2 and R
3 can together complete any convenient chalcogenazolium nucleus or hydrolyzed chalcogenazolium
nucleus, provided the chalcogen atom is a middle chalcogen atom. The middle chalcogen
atoms are sulfur, selenium, and tellurium, being designated "middle" chalcogen atoms
since they are the atoms in Group VI of the Periodic Table of Elements, except for
the highest and lowest in atomic number.
[0017] When X is sulfur or selenium, R
2 and R
3 can take any form found in known thiazolium and selenazolium ring containing nuclei.
R
2 and R
3 can individually take the form of hydrogen or halogen atoms; hydrocarbon moieties
(e.g., alkyl, aryl, alkaryl, or aralkyl) optionally linked through a divalent oxygen
or sulfur atom (e.g., an alkoxy, aryloxy, alkaryloxy, aralkoxy, alkylthio, arylthio,
alkarylthio, or aralkylthio group); cyano; an amino group, including primary, secondary,
and tertiary amino groups; an amido group (e.g., acetamido and butyramido); a sulfonamido
group (e.g., an alkyl or arylsulfonamido group); a sulfamoyl group (e.g., an alkyl
or arylsulfamoyl group); a ureido group (e.g., 1-ureido, 3-phenyl-1-ureido, or 3-methyl-1-ureido);
a thioureido group (e.g., a thioureido group corresponding to the above exemplary
ureido groups); hydroxy; or a -COM or -S(0)
2M group, wherein M is as described above.
[0018] The alkyl groups and the alkyl moeities of other groups preferably contain from 1
to about 8 carbon atoms (e.g., methyl, ethyl, propyl, butyl, amyl, hexyl, or octyl),
and most preferably contain from 1 to about 4 carbon atoms and may be further substituted
by other groups, such as halogen, cyano, aryl, carboxy, alkylcarbonyl, arylcarbonyl,
arylcarbonyl, and aminocarbonyl.
[0019] The aryl groups and the aryl moieties of other groups preferably contain 6 to about
10 carbon atoms (e.g., phenyl or naphthyl) and include substituted or unsubstituted
groups. Useful substituents include halogen, cyano, alkyl, carboxy, alkylcarbonyl,
arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, and aminocarbonyl.
[0020] In a preferred form, R
2 and R
3 together form one or more fused carbocyclic aromatic rings -e.g., a benzo or naphtho
ring, either of which can be optionally substituted. When X is sulfur or selenium,
the salt can be a benzothiazolium salt, a benzoselenazolium salt, an α- or p-naphthothiazolium
salt, or an α- or β-naphthoselenazolium salt, such as the quaternized but otherwise
unsubstituted salts or the salts in which the fused carbocyclic rings are substituted.
Fused carbocyclic ring substituents, when present, can be chosen from among those
identified above for R
2 and R
3 as individual substituents. In general, the fused carbocyclic ring substituents,
when present, can be chosen from among those present in comparable nuclei in cyanine,
merocyanine, and hemicyanine dyes.
[0021] When the middle chalcogen represented by Y is tellurium, R
2 and R
3 together form a carbocyclic aromatic ring, such as a fused benzo or an a- or β-naphtho
ring. The fused carbocyclic aromatic rings can be unsubstituted or substituted with
aliphatic or aromatic groups comprised of hydrocarbon moieties optionally linked through
a divalent oxygen or sulfur atom, amino groups, amido groups, sulfonamido groups,
sulfamoyl groups, ureido groups, thioureido groups, hydroxy groups, COM groups, and
S0
2M groups, wherein M is chosen to complete an acid, ester, thioester, or salt. Specifically
preferred benzo or naphtho ring substituents are alkyl, alkoxy, alkylthio, and hydroxy
substituents, where alkyl is preferably of from 1 to 8 carbon atoms, and most preferably
of from 1 to 4 carbon atoms.
[0022] Y is included in formulae (II) and (III) to provide electronically neutral compounds.
Y can be chosen from a wide range of ions known to be compatible with silver halide
emulsions. When the chalcogenazolium salt or the hydrolyzed chalcogenazolium salt
is a betaine, no charge balancing counter ion may be required, and n can be zero.
In the absence of an ionized substituent, the quaternized chalcogenazolium salt of
formula (II) has a single positive charge and R
4 is an acid anion, such as a halide or p-toluenesulfonate. In the absence of an ionized
substituent, the hydrolyzed quaternized chalcogenazolium salt of formula (III) has
a single negative charge and Y is a cation, such as that provided by the base employed
to effect hydrolysis - e.g.. an alkali or alkaline earth metal, or the ammonium cation.
[0023] Preferred chalcogenazolium salts useful in this invention have the structural formula
(V):

wherein:
R4, Y and n have the definitions noted above.
[0025] The chalcogenazolium salts described above, while disclosed in U. S. Patent 4,578,348
as being useful for improving speed/fog relationships in photographic recording materials,
including color photographic materials, are not recognized as having any utility with
respect to overcoming inhibition of silver halide development caused by particular
pyrazolotriazole magenta couplers.
[0026] The chalcogenazolium salts can be added to the silver halide emulsion at any time
following precipitation of the silver halide grains to just prior to coating. The
amount of chalcogenazolium salt which has been found to be effective to prevent silver
halide development inhibition by the pyrazolotriazole coupler compound, and which
is incorporated in the silver halide layer, is from about 0.01 to about 10 millimoles
thereof per mole of silver. The preferred concentration of salt is from about 0.1
to about 2.0 millimoles thereof per mole of silver.
[0027] This invention also relates to a process for reducing silver halide development inhibition
in a photographic recording material comprising a pyrazolotriazole magenta coupler
which comprises adding to a silver halide emulsion a hydrolyzable chalcogenazolium
salt of a middle chalcogen which comprises a quaternized substituent having a carbon
chain interrupted by a divalent group which has the structural formula:
-L-T(̵NH-T

mR
1 wherein:
L is a divalent linking group;
T is carbonyl or sulfonyl;
T' is independently in each occurrence carbonyl or sulfonyl;
R1 is a hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
[0028] The silver halide emulsions can include silver halide grains of any conventional
shape or size. Specifically, the emulsions can include coarse, medium or fine silver
halide grains of either regular (e.g., cubic or octahedral) or irregular (e.g. multiply
twinned or tabular) crystallographic form.
[0029] High aspect ratio tabular grain emulsions are specifically contemplated, such as
those disclosed by Wilgus et al U. S. Patent 4,434,226, Daubendiek et al U. S. Patent
4,414,310, Wey U. S. Patent 4,399,215, solberg et al U. S. Patent 4,433,048, Mignot
U. S. Patent 4,386,156, Evans et al U. S. Patent 4,504,570, Maskasky U. S. Patent
4,400,463, Wey et al U. S. Patent 4,414,306, Maskasky U. S. Patents 4,435,501 and
4,643,966 and Daubendiek et al U. S. Patents 4,672,027 and 4,693,964. Also specifically
contemplated are those silver bromoiodide grains with a higher molar proportion of
iodide in the core of the grain than in the periphery of the grain, such as those
described in GB 1,027,146; JA 54
/48521; US 4,379,837; US 4,444,877; US 4,665,012; US 4,686,178; US 4,565,778; US 4,728,602;
US 4,668,614; US 4,636,461; EP 264,954. The silver halide emulsions can be either
monodisperse or plolydisperse as precipitated. The grain size distribution of the
emulsions can be controlled by silver halide grain separation techniques or by blending
silver halide emulsions of differing grain sizes.
[0030] Sensitizing compounds, such as compounds of copper, thallium, lead, bismuth, cadmium
and Group VIII noble metals, can be present during precipitation of the silver halide
emulsion, as illustrated by U. S. Patent Nos. 1.195.432: 1,951,933; 2.448.060: 2,628,167;
2,950,972; 3,448,709 and 3.737,313.
[0031] The silver halide emulsions can be either monodispersed or polydispersed as precipitated.
The grain size distribution of the emulsions can be controlled by silver halide grain
separation techniques or by blending silver halide emulsions of differing grain sizes.
The emulsions can include Lippmann emulsions and ammoniacal emulsions, as illustrated
by Glafkides, Photographic Chemistry, Vol. 1, Fountain Press, London. 1958, pp. 365-368
and pp. 301-304; excess halide ion ripened emulsions as described by G. F. Duffin.
Photographic Emulsion Chemistry, Focal Press Ltd., London, 1966, pp. 60-72; thiocyanate
ripened emulsions, as illustrated by U. S. Patent No. 3,320,069; thioether ripened
emulsions, as illustrated by U. S. Patent Nos. 3,271,157; 3,574,628 and 3,737,313
or emulsions containing weak silver halide solvents, such as ammonium salts, as illustrated
by U. S. Patent No. 3.784,381 and Research Disclosure, No. 134, June 1975, Item 13452.
[0032] The silver halide emulsions can be surface sensitized. Noble metal (e.g., gold),
middle chalcogen (e.g., sulfur, selenium, or tellurium), and reduction sensitizers,
employed individually or in combination, are specifically contemplated. A preferred
method of sensitization is sulfur and gold.
[0033] Typical chemical sensitizers are listed in Research Disclosure, December 1978, Item
17643, Section III.
[0034] The silver halide emulsions can be spectrally sensitized with dyes from a variety
of classes, including the polymethine dye class, which includes the cyanines, merocyanines,
complex cyanines and merocyanines (i.e., tri-, tetra-, and polynuclear cyanines and
merocyanines), oxonols, hemioxonols, styryls, merostyryls, and streptocyanines. Illustrative
spectral sensitizing dyes are disclosed in Research Disclosure, Item 17643, cited
above, Section IV.
[0035] The silver halide emulsions as well as other layers of the photographic recording
materials of this invention can contain as vehicles hydrophilic colloids, employed
alone or in combination with other polymeric materials (e.g., lattices). Suitable
hydrophilic materials include both naturally occurring substances such as proteins,
protein derivatives, cellulose derivatives - e.g., cellulose esters, gelatin - e.g.,
alkali treated gelatin (cattle, bone, or hide gelatin) or acid treated gelatin (pigskin
gelatin), gelatin derivatives - e.g. acetylated gelatin, phthalated gelatin and the
like, polysaccharides such as dextran, gum arabic, zein, casein, pectin, collagen
derivatives, collodion, agar-agar, arrowroot, and albumin. The vehicles can be hardened
by conventional procedures. Further details of the vehicles and hardeners are provided
in Research Disclosure, Item 17643, cited above, Sections IX and X.
[0036] The effect of the invention is illustrated as follows:
A tabular grain silver bromoiodide (4.5 mole % I) emulsion having an equivalent circular
diameter of 3.2µm and a thickness of 0.14µm was prepared in the manner described in
U. S. Patent 4,433,048 of Solberg et al.
[0037] Portions of the emulsion were then chemically and spectrally sensitized to the green
region of the visible spectrum using sodium thiosulfate (2.5 mg
/Ag mole), potassium tetrachloroaurate (1.25 mg/Ag mole), sodium thiocyanate (80 mg/Ag
mole), a mixture of the green sensitizing dyes anhydro-5-chloro-9-ethyl-5'-phenyl-3'-(3-sulfobutyl)-3-(3-sulfopropyl)oxacarbocyanine
hydroxide, sodium salt and anhydro-11-ethyl-1,1'- bis(3-sulfopropyl)naphth-[1,2-d]oxazolocarbocyanine
hydroxide, sodium salt (0.7 millimole/Ag mole). To portions of the chemically and
spectrally sensitized emulsion were added a dispersion of the magenta dye-forming
coupler identified above as C-1. To one portion was added 36 mg/Ag mole of the chalcogenazolium
salt identified above as S-1. Two coatings comprising the above components were then
prepared in the following manner.
[0038] Separate portions of a gelatin subbed cellulose triacetate film support were coated
with the above- described coating formulations. The coverages were silver bromoiodide
(1.08 g Ag
/m
2), gelatin (2.15 g/m
2), magenta dye-forming coupler (0.57 g
/m
2). A protective overcoat was then applied comprising gelatin (2.15 g/m
2) and the hardener bis-vinyl sulfonyl methyl ether at a concentration of 1.75 percent
based on total gelatin.
[0039] The resulting photographic elements were imagewise exposed at 1/100 of a second through
a 0 -4.0 density step tablet plus a Wratten No. 9 filter (Wratten is a trademark of
Eastman Kodak Co., U.S.A.) to 600W, 5500 K tungsten light source. Processing was accomplished
at 37.7° C in a color process of the type described in the British Journal of Photography
Annual 1979, pages 204-206, at a development time of 2 minutes and 15 seconds. Results
showed the coating containing chalcogenazolium salt S-1 provided improved relative
speed and contrast values.
1. A photographic recording material comprising a support having thereon a photographic
silver halide emulsion layer and a pyrazolotriazole magenta coupler which inhibits
silver halide development, said recording material being characterized in that it
comprises a hydrolyzable chalcogenazolium salt of a middle chalcogen which comprises
a quaternized substituent having a carbon chain interrupted by a divalent group which
has the structural formula:
-L-T(̵NH-T
mR
1 wherein:
L is a divalent linking group;
T is carbonyl or sulfonyl;
T is independently in each occurrence carbonyl or sulfonyl;
R' is a hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
3. The recording material of claim 1 characterized in that the chalcogenazolium salt
has the structural formula:

wherein;
R2 and R3 are independently hydrogen; halogen; aliphatic or aromatic hydrocarbon moiety optionally
linked through a divalent oxygen or sulfur atom; cyano; amino; amido; sulfonamido;
sulfamoyl; ureido; thioureido; hydroxy; -COM or -S(SO)2M group, wherein M is chosen to complete an aldehyde, ketone, acid, ester, thioester,
amide, or salt; or R2 and R3 together can represent the atoms which complete a fused ring;
R4 is hydrogen; alkyl of from 1 to about 8 carbon atoms; or aryl of from 6 to 10 carbon
atoms;
Q represents a quaternized substituent;
X is a middle chalcogen atom;
Y represents a charge balancing counter ion; and
n is 0 or 1.
4. The recording material of claim 3 characterized in that R4 is hydrogen.
5. The recording material of claim 3 characterized in that quaternized substituent
Q has the formula:
-L-T(̵NH-T
1
R
1 wherein
L represents an optionally substituted alkylene group having from 1 to 8 carbon atoms;
T is carbonyl or sulfony;
T' is independently in each occurrence carbonyl or sulfonyl; and
R1 represents a primary or a secondary amino group or an alkyl group having from 1 to
about 8 carbon atoms hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
6. The recording material of claim 5 characterized in that T is carbonyl and T' is
sulfonyl.
7. The recording material of claim 5 characterized in that L is methylene or ethylene.
8. The recording material according to claim 5 characterized in that m is 1.
9. The recording material according to claim 3 characterized in that X is sulfur.
10. The recording material of claim 1 characterized in that the chalcogenazolium salt
is present in an amount of from about 0.01 to about 10 millimoles thereof per mole
of silver.
11. The recording material of claim 10 characterized in that the salt is present in
an amount of from about 0.1 to about 2.0 millimoles thereof per mole of silver.
12 The recording material of claim 9 characterized in that the chalcogenazolium salt
has the structural formula:
14. The recording material of claim 1 characterized in that the silver halide emulsion
is chemically sensitized.
15. The recording material of claim 14 characterized in that the emulsion is sensitized
with sulfur and gold.
16. A process for reducing silver halide development inhibition in a photographic
recording material comprising a pyrazolotriazole magenta coupler which comprises adding
to a silver halide emulsion from about 0.01 to about 10 millimoles per mole of silver
of a hydrolyzable chalcogenazolium salt of a middle chalcogen which comprises a quaternized
substituent having a carbon chain interrupted by a divalent group which has the structural
formula:
-L-T(̵NH-T
mR
1 wherein:
L is a divalent linking group;
T is carbonyl or sulfonyl;
T' is independently in each occurrence carbonyl or sulfonyl;
R' is a hydrocarbon residue or an amino group; and
m is an integer of from 1 to 3.
17. The process of claim 16 characterized in that from about 0.1 to about 2.0 millimoles
of chah cogenazolium salt are added per mole of silver.