Color photographic materials containing 5-pyrazolone polymeric couplers and solvents

Abstract

 Color photographic materials comprise a supporting substrate having coated thereon a silver halide emulsion and a coupler composition. The coupler composition comprises a polymeric magenta dye-forming coupler including a 5-pyrazolone coupler group and a sulfoxide or carbonamide solvent.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to color photographic materials comprising a substrate having coated thereon a silver halide emulsion and a coupler composition comprising a polymeric magenta dye-forming coupler and a sulfoxide or carbonamide solvent.

BACKGROUND OF THE INVENTION

[0002] Color photographic materials containing a silver halide emulsion are well known in the art, as is the development of such materials involving the reaction of an oxidized aromatic primary amine color developing agent with a dye-forming coupler. Various yellow, cyan and magenta dye-forming couplers are also known in the art. Particularly, the Ichijima et al U.S. Patents Nos. 4,301,235 and 4,310,619 and the Hirose et al U.S. Patent No. 4,584,226 disclose 2-equivalent 5-pyrazolone magenta dye-forming couplers for use in silver halide color photographic materials.

[0003] It is also known in the art that couplers may be incorporated in the form of a polymer which improves the ability of the dye to remain in the location where it is formed in a color photographic element. For example, Monbaliu et al disclose (U.S. Patent No. 3,926,436) photographic elements containing polymer couplers as latexes which show less foaming tendency and which show high compatibility with hydrophilic colloids such as gelatin. Yagihara et al (U.S. Patent No. 4,474,870) disclose photographic materials containing polymeric coupler latexes that form magenta dyes upon coupling with oxidized developing agents. Hirano et al (U.S. Patent No. 4,511,647) disclose color photographic materials containing cyan color forming coupler latexes. Yagihara et al (U.K. Patent No. 2.092,573 B) disclose silver halide photographic materials containing magenta color forming coupler latexes. Cawse and Harris (European Patent Application 0321399 A3) disclose a method of preparing latexes of color couplers.

[0004] Generally, three methods have been employed in the past for dispersing polymeric couplers. These three methods include: (1) dispersing the coupler by colloid milling or homogenization methods, along with high and/or low vapor pressure organic solvents in aqueous surfactant and gelatin; (2) direct incorporation of solutions of water soluble polymers; (3) latex formation by emulsion polymerization or suspension polymerization.

[0005] Hirano (U.S. Patent No. 4,522,916) discloses the preparation of polymeric magenta dye forming coupler latexes that provide images of improved light stability. Hirano and Furutachi (U.S. Patent No. 4,576,910) disclose the preparation of polymeric magenta dye forming coupler latexes formed from triazole and tetrazole monomers. Helling et al (U.S. Patent No. 4,756,998) disclose the preparation of polymeric couplers which contain at least one urethane or urea group. Yamanouchi et al (U.S. Patent No. 4874,689) disclose the preparation of polymeric couplers utilizing chain transfer agents of eight or more carbon atoms. Helling (U.S. Patent No. 4,921,782) discloses the preparation of polymeric magenta dye forming couplers, wherein the magenta coupler monomer contains a carboxyl group. Maekawa and Hirano (U.S. Patent No. 4,946,771) disclose the preparation of polymeric couplers formulated with certain advantageously incorporated coupling and noncoupling comonomers.

[0006] Polymeric couplers can be prepared by joining reactive couplers to synthesized polymers. Such polymers may include polyacrylic acid, poly-p-aminostyrene, and other natural high polymers. Methods for producing such polymeric couplers are described in U.S. Patents Nos. 2,698,797, 2,852,381, 2852,383, and 2,870,712 and in Japanese Patent Publications Nos. 16932/1960 and 3661/1969. Methods for forming polymeric couplers from ethylenically unsaturated monomers and other polymerizable monomers are disclosed in British Patents Nos. 880,206, 955,197, 967,503, 967,504, 995,363 and 1,104,658.

[0007] Jones discloses (U.S. Patent No. 2,561,205) the formation of water-soluble polymeric couplers derived from β,y-ethylenically unsaturated amides. Williams discloses (U.S. Patent No. 2,739,956) the formation of water-soluble polymeric couplers derived from vinyl-substituted monomers such as 2-vinyl-1-naphthol. Firestine discloses (U.S. Patent No. 2,976,294) water-soluble polymers derived from methacrylamide related monomers, such as 1-(m-methacryloylaminophenyl)-2-carboxy-5-pyrazolone.

[0008] Umberger (U.S. Patent No. 3,451,820) discloses dispersions of lipophilic color-forming polymeric couplers. Van Paesschen and Priem (U.S. Patent No. 4,080,211) disclose a process for making color-coupling agents by emulsion polymerization. Ponticello et al (U.S. Patent No. 4,215,195) disclose the preparation of cross-linkable polymers that contain color-forming coupler residues. Hirano el al (U.S. Patent No. 4,518,687) disclose a photographic material containing a cyan dye-forming oleophilic polymeric coupler. Lau and Tang (U.S. Patent No. 4,612,278) disclose photographic materials containing polymeric couplers copolymerized with alkoxyalkylacrylate monomers.

[0009] It is also well known in the color photographic art that couplers are used in combination with solvents and other addenda which facilitate their incorporation in the photographic materials and/or improve one or more properties of the dyes formed from the couplers. For example, Japanese Laid Open Application No. 62-141554 cited above discloses the use of polymeric couplers in combination with high-boiling organic phosphate solvents. Japanese Laid Open Application No. 58-224352 also cited above generally discloses the use of polymeric couplers in combination with various types of high-boiling organic solvents. Because of the varying effects that solvents can provide in combination with individual coupler compounds, there is a continuing need to provide combinations of couplers and solvents which further improve the color-forming properties of couplers.

[0010] Retouching of color photographic images is well known in the art, especially in the reversal film system. Retouching is carried out after the photographic material has been developed and processed. During retouching, magenta, yellow or cyan image dye may be selectively removed using appropriate bleach solutions. The ability to selectively bleach a color photographic image dye is an important characteristic of the parent image coupler.

SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide color photographic materials comprising a silver halide emulsion and a coupler composition coated on a supporting substrate. It is a further object of the invention to provide such color photographic materials having one or more improved properties useful in forming color images. It is a more specific object of the invention to provide color photographic materials comprising a silver halide emulsion and a coupler composition comprising a polymeric dye-forming coupler which exhibit enhanced selective bleachability during retouching of the photographic material. These and additional objects are provided by the color photographic materials of the present invention which comprise a supporting substrate having coated thereon a silver halide emulsion and a coupler composition. The coupler composition comprises a polymeric magenta dye-forming coupler including a 5-pyrazolone coupler group, and a solvent selected from formulas (I) and (II):


wherein R¹ and R² are, independently, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R¹ and R² form a ring structure;
   R³ and R⁴ are, independently, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R³ and R⁴ form a ring structure, and
   R⁵ is hydrogen, or a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R⁴ and R⁵ form a ring structure.

[0012] The present Inventors have discovered that the coupler compositions comprising the polymeric dye-forming coupler including a 5-pyrazolone coupler group and a sulfoxide or carbonamide solvent as described above, exhibit enhanced selective bleachability, for example, using an aqueous stannous chloride solution, whereby the photographic materials of the present invention are particularly suitable for use in reversal film systems.

[0013] These and additional objects and advantages provided by the color photographic materials and coupler compositions of the present invention will be more fully apparent in view of the following detailed description.

DETAILED DESCRIPTION

[0014] The color photographic materials of the invention comprise a supporting substrate having coated thereon a silver halide emulsion and a coupler composition. The coupler composition comprises a polymeric magenta dye-forming coupler including a 5-pyrazolone coupler group and a sulfoxide or carbonamide solvent. The combination of the specified solvent with the polymeric magenta dye-forming coupler provides the coupler with enhanced selective bleachability, whereby the color photographic materials of the invention are particularly suitable for use in reversal film systems.

[0015] The polymeric coupler included in the coupler compositions of the present photographic materials includes a 5-pyrazolone coupler group. The 5-pyrazolone coupler groups are well known in the art, as are their methods of preparation, as demonstrated in the Ichijima et al U.S. Patents Nos. 4,301,235 and 4,310,619, and the Hirose et al U.S. Patent No. 4,584,226. In a preferred embodiment, the 5-pyrazolone coupler group has one of the formulas (III) - (V):


wherein * represents the site for linkage to the polymeric chain;
   R⁶ is an arylamino, carbonamido, ureido, sulfonamido, alkylamino, or heterocyclic amino group, all of which groups may be substituted or unsubstituted;
   R⁷ is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group;
   X hydrogen or a group capable of being released by a coupling reaction with an oxidized aromatic primary amine developing agent; and
   X' is a divalent group derived from X having bonding sites to the pyrazolone ring and to a polymeric chain, and is capable of being released from the polymer chain during processing.

[0016] In a preferred embodiment, R⁷ in the coupler group comprises a substituted or unsubstituted aryl group. Suitable substituents for R⁷ include, but are not limited to, halogen atoms and cyano, alkylsulfonyl, arylsulfonyl, sulfamoyl, sulfonamido, carbamoyl, carbonamido, alkoxy, acyloxy, aryloxy, alkoxycarbonyl, aryloxycarbonyl, ureido, nitro, alkyl and trifluromethyl groups. Halogen-substituted aryl groups are particularly preferred.

[0017] In a further preferred embodiment, the coupler group is of formula (III), in which R⁷ is selected from the group consisting of substituted and unsubstituted aryl groups, and X represents:


   wherein Z_a, Z_b, Z_c, and Z_d are independently selected from the group consisting of substituted or unsubstituted methine groups and -N=. Suitable substituents for the methine group include, but are not limited to, substituted and unsubstituted alkyl groups and substituted and unsubstituted aryl groups. Examples of the nitrogen containing heterocyclic groups formed by Z_a, Z_b, Z_c and Z_d and the tertiary nitrogen atom include a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, and the like. Of these, a pyrazolyl group in which Z_a represents -N= and Z_b, Z_c and Z_d each represents a methine group or a substituted methine group is particularly preferred. In a further preferred embodiment, all of Z_b, Z_c and Z_d are unsubstituted.

[0018] In a further preferred embodiment, the 5-pyrazolone coupler group is connected to a polymeric chain including repeating units of the formula (VII):


wherein * represents the site for linkage to the 5-pyrazolone coupler group;
   R⁸ is hydrogen, chlorine or an alkyl group of from 1 to 4 carbon atoms;
   A is -CONH-, -COO-, -O- or a phenylene group,
   B is an unsubstituted or substituted, straight or branched alkylene group, an unsubstituted or substituted, straight or branched aralkylene group, or an unsubstituted or substituted phenylene group,
   Y is -CONR'-, -NR'CONR'-, -NR'-COO-, -NR'CO-, -OCONR'-, -NR'-, -COO-, -OCO-, -CO-, -O-, -SO₂-, - NR'SO₂-, or -SO₂NR'-, wherein R' is a hydrogen atom, or a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aryl group, or when two or more R' substituents are present in Y, the two or more R' substituents may be the same or different;
   q is 0 or 1; and
   p is the same as q.

[0019] Polymeric couplers of this type, and their methods of preparation, are disclosed, for example, in the Yagihara et al U.S. Patent No. 4,367,282. With reference to the polymer chain including repeating units of the formula (VII) set forth above, in a preferred embodiment, A is -CONH- and p and q are 0.

[0020] In a further embodiment, the polymeric couplers according to the present invention may contain a non-dye-forming repeating unit which is derived from any suitable ethylenically-unsaturated monomer. Ethylenically unsaturated monomers which may be used to form non-dye-forming repeating units in the polymeric coupler include but are not limited to, esters, for example, lower alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate, hexyl acrylate, methyl methacrylate, octyl methacrylate, lauryl methacrylate, vinyl esters such as vinyl acetate, vinyl propionate, vinyl laurate, acrylonitrile, methacrylonitrile, amides, for example, acrylamide and methacrylamide, vinyl aromatics, for example, styrene and derivatives thereof including vinyl toluene, divinylbenzene, vinyl ethers, and the like.

[0021] The polymeric couplers according to the present invention may be formed by any of the known polymerization techniques for the polymerization of ethylenically unsaturated monomers. Emulsion polymerization methods are particularly suitable as disclosed in the Yagihara et al U.S. Patent No. 4,367,282. In accordance with well known polymerization techniques, the polymeric couplers may be formed as homogeneous latex particles or, alternatively, may be in the form of core-shell latex particles as taught, for example, in the Hirano et al U.S. Patent No. 4,444,870.

[0022] Alternatively, the polymer latex is formed by solution polymerization of monomer mixture comprising a coupler monomer, a comonomer, and an ionic comonomer containing sulfonic, sulfuric, sulfinic, carboxylic or phosphoric acid, such as acrylamido-2,2'-dimethylpropane sulfonic acid, 2-sulfoethyl methacrylate, or sodium styrene sulfonate. The polymer solution obtained is then dispersed in aqueous solution to form a latex.

[0023] A third way of forming polymer latex is by solution polymerization of monomer mixture comprising a coupler monomer and comonomers. An organic solvent is used for dissolving the polymeric coupler and the solution is dispersed in an aqueous solution of gelatin in the form of latex as described in U.S. Patents Nos. 4,668,613; 4,874,689 and 4,946,771.

[0024] While the amount of the color forming repeating units in the polymeric coupler may be varied, it is preferred that the polymeric coupler contain from about 20 to about 80 mol percent of the color-forming repeating unit and from about 80 to about 20 mol percent of non-color forming repeating units.

[0025] Specific polymeric couplers for use in the color photographic materials of the present invention, include, but are not limited to, couplers comprising repeating units according to the following formulas:
































   In the color photographic materials of the present invention, the polymeric 5-pyrazolone polymeric couplers is employed in combination with a sulfoxide or carbonamide solvent. The sulfoxide and carbonamide solvents may be used individually, or in any combination, and may be used in combination with other conventional solvents. It is an important feature that the sulfoxide and carbonamide solvents employed in the coupler compositions contain sufficient ballast to minimize their water solubility, volatility and diffusivity.

[0026] Suitable sulfoxide compounds for use in the coupler compositions are of the formula (I):


wherein R¹ and R² are independently selected from the group consisting of substituted and unsubstituted alkyl groups, substituted and unsubstituted alkenyl groups, and substituted and unsubstituted aryl groups, or R¹ and R² form a ring structure. The alkyl and alkenyl groups from which R¹ and R² are formed may be straight or branched chain. Suitable substituents for the alkyl, alkenyl and aryl groups include, but are not limited to, alkoxy, aryloxy, aryl, alkoxycarbonyl, aryloxycarbonyl, acyloxy, carbonamido and carbamoyl groups and halogen atoms. In preferred embodiments, R¹ and R² are individually selected from straight and branched chain alkyl groups and straight and branched chain alkenyl groups or R¹ and R² form a ring structure. In order to ensure that water solubility, volatility and diffusivity of the solvent are reduced, it is preferred that R¹ and R² contain a total of least 12 carbon atoms, and more preferably from about 16 to about 24 carbon atoms.

[0027] Suitable sulfoxides include, but are not limited to, the following:



        n-C₇H₁₅S(=O)C₇H₁₅-n   (s-i)





        CH₃(CH₂)₃CH(C₂H₅)CH₂S(=O)CH₂CH(C₂H₅)(CH₂)₃CH₃   (s-ii)





        n-C₉H₁₉S(=O)C₉H₁₉-n   (s-iii)





        CH₃(CH₂)₄C(CH₃)₂CH₂S(=O)CH₂C(CH₃)₂(CH₂)₄CH₃   (s-iv)






        CH₃S(=O)(CH₂)₁₆C(=O)N(C₄H₉)₂   (s-viii)




   Carbonamide compounds suitable for use as the solvent in the coupler compositions of the invention are of the formula (II):


wherein R³ and R⁴ are independently selected from the group consisting of substituted and unsubstituted alkyl groups, substituted and unsubstituted alkenyl groups, and substituted and unsubstituted aryl groups, or R³ and R⁴ form a ring structure, and
   R⁵ is hydrogen, or a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group. The alkyl and alkenyl groups which may form R³, R⁴ and/or R⁵ may be straight or branched chain and may be substituted or unsubstituted. Suitable substituents for R³, R⁴ and R⁵ include, but are not limited to, alkoxy, aryloxy, aryl, alkoxycarbonyl, aryloxycarbonyl and acyloxy groups. In a preferred embodiment, R³ is a straight or branched chain alkyl group, straight or branched chain alkenyl group or an aryl-substituted alkyl group, or R³ and R⁴ form a ring structure. In an alternate preferred embodiment, R⁴ and R⁵ are individually a phenyl-substituted or unsubstituted, straight or branched chain alkyl group. In order to ensure that water solubility, volatility and diffusivity of the solvent are reduced, R³, R⁴ and R⁵ preferably contain a total of at least 12 carbon atoms, and more preferably from about 15 to about 30 carbon atoms.

[0028] Suitable carbonamides include, but are not limited to, the following:










   Preferred carbonamides include N,N-diethyl lauramide, N-n-butylacetanilide, N-n-amylphthalamide, N,N-di-n-butyl carbamate, N,N-dibutyl lauramide, N,N-diethylcapramide, N,N,N',N'-tetraethyl phthalamide, and N-n-amylsuccinimide.

[0029] The solvent is combined with the polymeric coupler in an amount sufficient to enhance the selective bleachability of the polymeric coupler. In a preferred embodiment, the coupler composition contains the polymeric coupler and the solvent in a weight ratio range of from about 1:0.1 to about 1:10, more preferably in a range of from about 1:0.1 to about 1:2.

[0030] The photographic materials of the present invention may be simple elements or multilayer, multicolor elements. The element typically will have a total thickness (excluding the support) of from 5 to 30 microns. The support may be transparent or reflective.

[0031] Suitable materials for use in the elements of this invention are disclosed in Research Disclosure, December 1978, Item 17643; January 1983, Item 22534; and December 1989, Item No. 308119 published by Kenneth Mason Publications, Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire P010 7DQ, ENGLAND. This publication will be identified hereafter by the term "Research Disclosure." The elements of the invention can comprise emulsions and addenda described in these publications and publications referenced in these publications.

[0032] The silver halide emulsions employed in the color photographic materials of this invention can be comprised of silver bromide, silver chloride, silver iodide, silver chlorobromide, silver chloroiodide, silver bromoiodide, silver chlorobromoidide or mixtures thereof. The emulsions can include silver halide grains of any conventional shape or size. Specifically, the emulsions can include coarse, medium or fine silver halide grains. Useful tabular grain emulsions are described in Research Disclosure, Item 22534, and in U.S. Patent No. 4,748,106. 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 4,424,310, Wey U.S. Patent 4,399,215, Solberg et al U.S. Patent 4,433,048, Mignot U.S. Patent 4,386,145, 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 4,4414,966 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 British Reference No. 1,027,146; Japanese Reference No. 54/48,521; U.S. Patents Nos. 4,379,837; 4,444,877; 4,665,012; 4,686,178; 4,565,778; 4,728,602; 4,668,614 and 4,636,461; and in European Reference No. 264,954. The silver halide emulsions can be either monodisperse or polydisperse 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.

[0033] 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.

[0034] The emulsions can be surface-sensitive emulsions, that is, emulsions that form latent images primarily on the surfaces of the silver halide grains, or internal latent image-forming emulsions, that is, emulsions that form 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.

[0035] The silver halide emulsions can be surface sensitized, and noble metal (e.g., gold), middle chalcogen (e.g., sulfur, selenium, or tellurium) and reduction sensitizers, employed individually or in combination, are specifically contemplated. Typical chemical sensitizers are listed in Research Disclosure, Item 17643, cited above, Section III.

[0036] The silver halide emulsions can be spectrally sensitized with dyes from a variety of classes. Illustrative spectral sensitizing dyes are disclosed in Research Disclosure, Item 17643, cited above, Section IV.

[0037] Suitable vehicles for the emulsion layers and other layers of elements of this invention are described in Research Disclosure Item 17643, Section IX and the publications cited therein.

[0038] In addition to the polymeric 2-equivalent 5-pyrazolone magenta couplers described herein, the elements of this invention can include additional couplers as described in Research Disclosure Section VII, paragraphs D, E, F and G and the publications cited therein. These additional couplers can be incorporated as described in Research Disclosure Section VII, paragraph C, and the publications cited therein.

[0039] The photographic elements of this invention can contain brighteners (Research Disclosure Section V), antifoggants and stabilizers (Research Disclosure Section VI), antistain agents and image dye stabilizers (Research Disclosure Section VII, paragraphs I and J), light absorbing and scattering materials (Research Disclosure Section VIII), hardeners (Research Disclosure X), coating aids (Research Disclosure Section XI), plasticizers and lubricants (Research Disclosure Section XII), antistatic agents (Research Disclosure Section XIII), matting agents (Research Disclosure Sections XII and XVI) and development modifiers (Research Disclosure Section XXI).

[0040] The photographic elements can be coated on a variety of supports as described in Research Disclosure Section XVII and the references described therein.

[0041] Preferred color developing agents are p-phenylenediamines. Especially preferred are 4-amino-3-methyl-N,N-diethylaniline hydrochloride, 4-amino-3-methyl-N-ethyl-N-β-(methanesulfonamido)-ethylaniline sulfate hydrate, 4-amino-3-methyl-N-ethyl-N-β-hydroxyethylaniline sulfate, 4-amino-3-β-(methanesulfonamido)ethyl-N,N-diethylaniline hydrochloride and 4-amino-N-ethyl-N,N-diethylaniline hydrochloride and 4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluenesulfonic acid.

[0042] With negative-working silver halide, the processing step described above provides a negative image. The described elements are preferably processed in the known C-41 color process as described in, for example, the British Journal of Photography Annual, 1988, pages 196-198. 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 then uniformly fogging the element to render unexposed silver halide developable. Alternatively, a direct positive emulsion can be employed to obtain a positive image. Preferably, the color photographic materials of the invention are of the color reversal type.

[0043] Development is followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver or silver halide, washing, and drying.

[0044] As is known in the art, the solution used to selectively bleach magenta dyes typically comprises aqueous stannous chloride. The present Inventors have discovered that the coupler compositions containing a 5-pyrazolone polymeric coupler and a sulfoxide or carbonamide solvent of the present invention exhibit good selective bleachability. This feature is particularly important in reversal film systems whereby the color photographic materials of the present invention are particularly suitable for use in such reversal film systems.

[0045] The advantages of the color photographic materials of the present invention are demonstrated in the following examples. Throughout the examples and the entire specification, parts and percentages are by weight unless otherwise specified.

Synthesis of Polymer P-1

[0046] This example demonstrates the preparation of polymer P-1 using solution polymerization techniques. 550g of deionized water, 1.875g of sodium N-methyl-N-oleoyltaurate (Igepon T-77), and 50ml of methanol were mixed in a 1L 4-neck round bottom flask equipped with a mechanical stirrer, nitrogen inlet, and condenser. The flask was immersed into a constant temperature bath at 80oC and heated for 30 minutes with nitrogen purging through. 7.5 ml of 5% ammonium persulfate was added and stirred for 3 minutes. The monomer solution comprising 15g of N-(4',5'-dihydro-5'-oxo-1'-(2,4,6-trichlorophenyl) (1,4'-bi-1H-pyrazol)-3'-yl)-2-methyl-2-propenamide, 20.62g of ethoxyethyl acrylate, 1.875g of acrylamido undecanoic acid and 225 mL of methanol was then added to the reactor over 3 hours and polymerized for 3 more hours. The latex was cooled, filtered and dialyzed against distilled water for overnight. It was then concentrated to 15.4% solid with Amicon's Ultrafiltration unit. The Z-average particle size measured by Malvern's Autosizer IIC was 69nm. The elemental analysis result was C(51.8%), H(5.9%), N(7.06%) and C1(10.36%). Yield was 83.8%.

[0047] Other polymeric couplers of this invention were prepared by a similar method.

EXAMPLE 1

[0048] In this example, color photographic materials containing coupler compositions according to the present invention were tested for bleachability. For comparison purposes, color photographic materials containing coupler compositions which did not include a solvent were also tested for bleachability. In preparing the color photographic materials, gelatin, water, surfactant and TAI were combined and the respective coupler was added to the resulting solution. The polymeric couplers were added in the form of a polymer latex. The solvent, when employed, was then added to the coupler-containing solution and the solution was stirred for at least one hour prior to addition of the silver halide emulsion. A coupler:solvent weight ratio of 1:0.5 was used when the solvent was present. The coupler-silver halide emulsion mixture was then coated on a supporting substrate. The exposure step was conducted for 0.02 sec and employed a 1B sensitometer, a 0-3 step tablet, a 0.9 neutral density filter and a DLV filter. The processing steps were conducted at 98.4°F as follows:

Step	Time	Atmosphere
MQ Development	6 minutes	N₂ burst
Wash	2 minutes	N₂ burst
Reversal Bath	2 minutes	N₂ burst
Color Development	6 minutes	N₂ burst
Conditioner	2 minutes	N₂ burst
Bleach	(Table I)	Continuous Air
Fix	4 minutes	Continuous Air
Wash	4 minutes	Continuous Air

[0049] In determining the bleachability, the following procedure was employed. The status A density (1.0) was read on a processed strip. A square (1/4 inch) was then blanked off on the processed strip using tape as a border. A swab was dipped in a fresh bleach solution and smeared on the squared portion for a predetermined period of time as set forth in Table I, after which the strip was washed in water for five minutes. After drying the status A density of the squared portion of film was reread and the percent of density loss was calculated.

[0050] The results of the bleachability testing are set forth in Table I. With reference to Table I, couplers (P-1), (P-2) and (P-8) are the polymeric couplers according to the present invention previously described in the specification. In Table I, the solvents are abbreviated as follows:
   S1: N,N-diethyl lauramide
   S2: bis ethyl hexyl sulphoxide
With further reference to Table I, bleached solution B1 comprised 5 g stannous chloride (SnCl₂), 30 ml of a 10% H₂SO₄ solution and 65 ml water. Bleach solution B2 comprised 5 g stannous chloride, 30 ml of a 1N HCl solution and 65 ml water. For each coupler and solvent, the time of bleaching and the bleach solution employed and resulting percent of density loss are set forth in Table I.

TABLE I

Coupler	Solvent	Time of Bleaching (Minutes)	Bleaching Solution	%Loss	Remark
P-8	none	6	B1	72.6	C
P-8	S1	6	B1	91.5	I
P-1	none	6	B1	36.2	C
P-1	S1	6	B1	82.5	I
P-8	none	2	B1	65.5	C
P-8	S1	2	B1	88.7	I
P-1	none	2	B1	29.5	C
P-1	S1	2	B1	71.1	I
P-8	none	0.5	B1	43.4	C
P-8	S1	0.5	B1	82.1	I
P-1	none	0.5	B1	19.1	C
P-1	S1	0.5	B1	49.5	I
P-2	none	6	B2	42.9	C
P-2	S2	6	B2	61.5	I
P-2	S1	6	B2	75.8	I
* C=Comparison; I=Invention

The results set forth in Table I demonstrate that the coupler compositions employed in the present photographic materials containing the polymeric coupler in combination with a sulfoxide or carbonamide solvent exhibit significantly enhanced selective bleachability. Thus, the color photographic materials of the present invention are particularly useful for reversal film systems.

EXAMPLE 2

[0051] In this example, additional bleachability tests were performed generally in accordance with the procedures described in Example 1. The film strips employed in this example contained a coupler composition comprising polymeric coupler (P-6) as set forth above. Bleaching solution B2 comprising aqueous stannous chloride and hydrochloric acid was employed and a two minute bleach treatment was conducted. The solvents S1 and S2 described in Example 1 were employed. For comparison purposes, photographic materials containing solvents outside the scope of the present invention, namely, S3 (p-dodecyl phenol) and S4 (ethylhexyl hydroxy benzoate) were also prepared and tested. The coupler:solvent weight ratio was 1:0.5. The resulting percent of density loss for each solvent employed is set forth in Table II.

TABLE II

Solvent	% Loss
S1 (invention)	55
S2 (invention)	45
S3 (comparison)	16
S4 (comparison)	25
None (comparison)	27

[0052] The results set forth in Table II further demonstrate that the color photographic materials of the present invention containing a coupler composition comprising a polymeric 5-pyrazolone magenta coupler and a sulfoxide or carbonamide solvent exhibit enhanced selective bleachability as compared with color photographic materials formed from 5-pyrazolone magenta couplers and other solvents, or in the absence of a solvent.

EXAMPLE 3

[0053] In this example, color photographic films were prepared and processed using the general procedures of Example 1. The polymeric couplers employed in the coupler compositions of the photographic films are set forth in Table III. The couplers were used in combination with a carbonamide solvent comprising N,N-diethyl lauramide in a 1:0.5 coupler:solvent weight ratio and the percent of density loss was measured. The bleach solution comprised B1 described in Example 1. For comparison purposes, similar photographic films were prepared and processed in the absence of the carbonamide solvent. The percent of density loss for photographic films comprising the various coupler compounds, both with and without the carbonamide solvent, are set forth in Table III.

TABLE III

Coupler	% Loss No Solvent	% Loss With Solvent
P-1	56.7	92.0
P-3	51.1	81.5
P-4	46.2	87.9
P-5	26.8	60.2
P-6	27.0	67.7
P-7	30.9	88.4

[0054] The results set forth in Table III demonstrate that the photographic materials containing the coupler composition including the carbonamide solvent exhibited enhanced selective bleachability as compared with the films prepared without the use of the carbonamide solvent.

Claims

1. A color photographic material comprising a supporting substrate having coated thereon a silver halide emulsion and a coupler composition comprising a polymeric magenta dye-forming coupler containing a 5-pyrazolone coupler group and a solvent of formula (I) or (II):

wherein R¹ and R² are, independently, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R¹ and R² form a ring structure;
   R³ and R⁴ are, independently, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R³ and R⁴ form a ring structure, and
   R⁵ is hydrogen, or a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group, or R⁴ and R⁵ form a ring structure.

2. A color photographic material as defined by claim 1, wherein R¹ and R² contain a total of at least 12 carbon atoms, and R³, R⁴ and R⁵ contain a total of at least 12 carbon atoms.

3. A color photographic material as defined by claim 1, wherein the solvent is of formula (I), and R¹ and R² are individually a straight or branched chain alkyl group or a straight or branched chain alkenyl group, and R³ is a straight or branched chain alkyl group, a straight or branched chain alkenyl group or an aryl-substituted alkyl groups.

4. A color photographic material as defined by claim 1, wherein R¹ and R² form a ring structure, and R³ and R⁴ form a ring structure.

5. A color photographic material as defined by any of claims 1-4, wherein the coupler composition contains the polymeric coupler and the solvent in a weight ratio of from about 1:0.1 to about 1:10.

6. A color photographic material as defined by any of claims 1-5, wherein the polymeric coupler contains a 5-pyrazolone coupler group having one of the formulas (III) - (V):



wherein * represents the site for linkage to the polymeric chain;
   R⁶ is an arylamino, carbonamido, ureido, sulfonamido, alkylamino, or heterocyclic amino group, all of which groups may be substituted or unsubstituted;
   R⁷ is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group;
   X hydrogen or a group capable of being released by a coupling reaction with an oxidized aromatic primary amine developing agent; and
   X' is a divalent group derived from X having bonding sites to the pyrazolone ring and to a polymeric chain, and is capable of being released from the polymer chain during processing.

7. A color photographic material as defined by claim 6, wherein the 5-pyrazolone coupler group is connected to a polymeric chain including repeating units of the formula (VII):

wherein * represents the site for linkage to the 5-pyrazolone coupler group;
   R⁸ is hydrogen, chlorine, or an alkyl group of from 1 to 4 carbon atoms;
   A is -CONH-, -COO-, -O- or a phenylene group,
   B is an unsubstituted or substituted, straight or branched alkylene group, an unsubstituted or substituted, straight or branched aralkylene group, or an unsubstituted or substituted phenylene groups,
   Y is -CONR'-, ,-NR'CONR'-, -NR'-COO- -NR'CO-, -OCONR'-, -NR'-, -COO-, -OCO-, -CO-, -O-, -SO₂-, - NR'SO₂-, and -SO₂NR'-, wherein R' is a hydrogen atom, or a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aryl group, or when two or more R' substituents are present in Y, the two or more R' substituents may be the same or different;
   q is 0 or 1; and
   p is the same as q.

8. A color photographic material as defined by claim 6 or 7, wherein the 5-pyrazolone coupler group is of formula (III), R⁷ is a substituted or unsubstituted aryl groups, and X represents:

   wherein Z_a, Z_b, Z_c, and Z_d are, independently, a substituted or unsubstituted methine group or -N=.

9. A color photographic material as defined by any of claims 6-8, wherein Z_b, Z_c and Z_d are individually selected from substituted or unsubstituted methine groups.

10. A coupler composition comprising a polymeric magenta dye-forming coupler including a 5-pyrazolone coupler group and a solvent as defined in any of claims 1-5, 8 or 9.