PROCESS FOR FORMING COLOR IMAGE

Abstract: A process for forming a color image is disclosed, comprising developing a silver halide photographic material using a developer containing an aromatic primary amine in the presence of at least one couplers represented by the following formulae (I) and (II): wherein R₁ represents an alkyl group, an aryl group, or a heterocyclic group; R₂ represents a hydrogen atom or a sub­ stituent group; and X represents a hydrogen atom or a cou­ pling split-off group: wherein R₁ and X have the same meanings as in the formula (I), respectively; and R'₂ represents an alkyl group, an aryl group, an alkylthio group, an arylthio group, or a heterocyclic thio group. According to the process of the invention, sensitivity, gradation (gamma) and color density of the developed image are improved.

Description: The present invention relates to a process for forming a color image comprising developing a silver halide photographic material using a developer containing an aromatic primary amine in the presence of at least one coupler. Said process can increase the photographic speed, improve the gradation (gamma) and heighten the color density of the developed image. It is well known that color developing agents of the aromatic primary amine type which have been oxidized with exposed silver halides as oxidants react with couplers to produce indophenol, indoaniline, indamine azomethine, phenoxazine, phenazine and their analogous dyes, thus forming color images. A magenta color image is formed by using couplers of a 5-pyrazolone, cyanoacetophenone, indazolone, pyrazolobenzimidazole or pyrazolotriazole type. Most of the magenta color image-forming couplers which have so far been widely used are 5-pyrazolones. However, it is known that the dyes formed from 5-pyrazolone couplers have an unnecessary absorption containing a yellow component in the neighborhood of 430 nm to cause color turbidity. As magenta color image forming nuclei which enable the reduction of this yellow component, there have been proposed pyrazolobenzimidazole nuclei in British Patent 1,047,612, indazolone nuclei in U.S. Patent 3,770,447 and pyrazolo-[5,1-b]-1,2,4-triazole nuclei in U.S. Patent 3,725,067. However, the magenta couplers described in the foregoing patent specifications also have such undesirable properties that when mixed with a silver halide emulsion in a condition that they are dispersed in a hydrophilic protective colloid like gelatin, some of them provide only unsatisfactory color images, have low solubility in high boiling organic solvents, are difficult to synthesize, have relatively low coupling activity in an ordinary developer or provide dyes of extremely poor fastness to light. As a result of various searches for new types of magenta color image-forming couplers having no side absorption at wavelengths around 430 nm, which is the most serious defect of 5-pyrazolone couplers in respect to hue, it was found that 1H-pyrazolo[1,5-b]-1,2,4-triazole magenta couplers which show no side absorption in the shorter wavelength side, produce a dye image of high fastness and can be synthesized with ease as disclosed in Japanese Patent Application (OPI) No. 171956/84 (the term "OPI" as used herein means an "unexamined published application ") and U.S. Patent 4,540,654, corresponding to EP-A-119860. Said document discloses magenta forming couplers of the pyrazolo triazolo type having the general formula wherein R and R₁ are each H, halogen or various aliphatic or cyclic substituents; X is H or a coupling releasable group or R₁ , R₂ or X may form a bis-coupler; or R₁ or R₂ may link to a vinyl group of a vinyl monomer to form a polymer coupler. These couplers have advantages in that they are excellent in color reproducibility, can be synthesized with ease, and can be readily converted to so-called two equivalent couplers by introducing a split-off group to a coupling active site, thus achieving reduction of the amount of silver to be used. However, when a coupling split-off group (X) is a group which facilitates the synthesizing of the resulting coupler, e.g. a halogen atom, an alkylthio group or an arylthio group, there arises a problem that such couplers are inferior to 5-pyrazolone magenta couplers in respect to sensitivity and gradation (gamma). It has been found that couplers having an aryloxy group as a coupling split-off group can solve the above-described problem. However, the aryloxy group-releasing couplers suffer from disadvantages that they are obtained in a low yield to be unsuitable for large-scaled synthesis and that they have low stability. Also, pyrazoloazoles described in the above-cited U.S. Patent 3,725,067 have similar defects. These couplers are also disclosed in GB-A-2135788. It is therefore the object of the present invention to provide a process for forming a color image comprising a magenta coupler having higher sensitivity and improved gradation (gamma). Said object is achieved by a process for forming a color image comprising developing a silver halide photographic material using a developer containing an aromatic primary amine in the presence of at least one coupler characterized in that said coupler is represented by the following formula (I) or (II): wherein R₁ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a heterocyclic group; R₂ represents a hydrogen atom or a substituent group; and X represents a split-off group linked through a nitrogen or sulfur atom; wherein R₁ and X have the same meanings as in formula (I), respectively; and R'₂ represents an alkyl group, an aryl group, an alkylthio group, an arylthio group, or a hetercyclic thio group. More specifically, R₁ represents an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a trifluoromethyl group, a phenylmethyl group, a methoxyethyl group, a 2-phenoxyethyl group, a 2-methylsulfonylethyl group, a 2-hydroxyethyl group, a 3,3,3-trifluoropropyl group, a 2-fluoroethyl group, a 2-chloroethyl group, a 2-bromoethyl group, a 2-cyanoethyl group, or a 3-oxobutyl group; an aryl group such as a phenyl group, a 4-methylphenyl group, a 4-t-butylphenyl group, a 4-acylaminophenyl group, a 4-halogenophenyl group, or a 4-alkoxyphenyl group: or a heterocyclic group such as a 2-furyl group, a 2-thienyl group, a 2-pyrimidyl group, a 2-benzothiazolyl group, a 2-pyridyl group, a 3- pyridyl group, or a 4-pyridyl group. R₂ represents a hydrogen atom, a halogen atom (e.g., a chlorine atom or a bromine atom), an alkyl group [including substituted alkyl groups such as a sulfonamido substituted alkyl group (e.g., a sulfonamidomethyl group, a 1-sulfonamidoethyl group, a 2-sulfonamidoethyl group, a 1-methyl-2-sulfonamidoethyl group or a 3-sulfonamidopropyl group), an acylamino-substituted alkyl group (e.g., an acylaminomethyl group, a 1-acylaminoethyl group, a 2-acylaminoethyl group, a 1-methyl-2-acylaminoethyl group, or a 3-acylaminopropyl), a sulfonamido-substituted phenylalkyl group (e.g., a p-sulfonamidophenylmethyl group, a p-sulfonamidophenylethyl group, a 1- (p-sulfonamidophenyl) ethyl group, or a p-sulfonamidophenylpropyl group), an acylamino-substituted phenylalkyl group (e.g., a p-acylaminophenylmethyl group, a p-acylaminophenylethyl group, a 1-(p-acylaminophenyl)ethyl group, or a p-acylaminophenyl-propyl group), an alkylsulfonyl-substituted alkyl group (e.g., a 2-dodecylsulfonylethyl group, a 1-methyl-2-penta-decylsulfonylethyl group, or an octadecylsulfonylpropyl group), a phenylsulfonyl-substituted alkyl group (e.g., a 3-(2-butyl-5-t-octylphenylsulfonyl)propyl group, or a 2-(4-dodecyloxy-phenylsulfonyl)ethyl group) and unsubstituted alkyl groups such as a methyl group, an ethyl group, a hexyl group , or a dodecyl group], an aryl group [including substituted aryl groups such as a sulfonamidophenyl group, a acylaminophenyl group, an alkoxyphenyl group, an aryloxyphenyl group, a substituted-alkylphenyl group, a sulfonamidonaphthyl group, or an acylaminonaphthyl group, and unsubstituted aryl groups such as a phenyl group, or a naphthyl group], a heterocyclic group (e.g., a 2-furyl group, a 2-thienyl group, a 2-pyrimidyl group, or a 2-benzothiazolyl group), a cyano group, an alkoxy group (e.g. a methoxy group, an ethoxy group, a 2-methoxyethoxy group, a 2-dodecylethoxy group, or a 2-methanesulfonylethoxy group), an aryloxy group (e.g. a phenoxy group, a 2-methylphenoxy group, or a 4-t-butylphenoxy group), an acylamino group (e.g., an acetamido group, a benzamido group, a tetradecanamido group, an α-(2,4-di-t-amyl-phenoxy)butylamido group, a γ-(3-t-butyl-4-hydroxyphenoxy)butylamido group, or an α-{4-(4-hydroxyphenylsulfonyl)phenoxy} decanamido group) an anilino group (e.g. a phenylamino group, a 2-chloroanilino group, a 2-chloro-5-tetradecanamidoanilino group, a 2-chloro-5-dodecyloxycarbonylanilino group, a N-acetylanilino group, or a 2-chloro-5-{α-(3-t-butyl-4-hydroxyphenoxy) dodecanamido}anilino group), a ureido group (e.g., a phenylureido group, a methylureido group, or a N,N-dibutylureido group), a sulfamoylamino group (e.g., a N,N-dipropylsulfamoylamino group, or a N-methyl-N-decylsulfamoylamino group), an alkylthio group (e.g., a methylthio group, an octylthio group, a tetradecylthio group, a 2-phenoxyethylthio group, a 3-phenoxypropylthio group, or a 3-(4-t-butylphenoxy)propylthio group), an arylthio group (e.g.,a phenylthio group, a 2-butoxy-5-t-octylphenylthio group, a 3-pentadecylphenylthio group, a 2-carboxyphenylthio group, or a 4-tetradecanamidophenylthio group), an alkoxycarbonylamino group (e.g., a methoxycarbonylamino group, or a tetradecyloxycarbonylamino group), a sulfonamido group (e.g., a methanesulfonamido group, a hexadecanesulfonamido group, a benzenesulfonamido group, a p-toluenesulfonamido group, an octadecanesulfonamido group, or a 2-methoxy-5-t-butylbenzenesulfonamido group), a carbamoyl group (e.g., a N-ethylcarbamoyl group, a N,N-dibutylcarbamoyl group, 1 N-(2-dodecyloxyethyl)carbamoyl group, a N-methyl-N-dodecylcarbamoyl group, or a N-{3-(2,4-di-t-amylphenoxy) propyl}-carbamoyl group), a sulfamoyl group (e.g., a N-ethylsulfamoyl group, a N,N.dipropylsulfamoyl group, a N-(2-dodecyloxy-ethyl)sulfamoyl group, a N-ethyl-n-dodecylsulfamoyl group, or a N,N-diethylsulfamoyl group), a sulfonyl group (e.g., a methanesulfonyl group, an octanesulfonyl group, a benzenesulfonyl group, or a toluenesulfonyl group), or an alkoxycarbonyl group (e.g. a methoxycarbonyl group, a butoxycarbonyl group,, a dodecylcarbonyl group, or anm octadecylcarbonyl group). Of the groups set forth above, an alkyl group, an aryl group, an alkylthio group and a arylthio group, especially an alkyl group and an aryl group, are preferred over others. R'₂ represents a substituted alkyl group such as a sulfonamido-substituted alkyl group (e.g., a sulfonamidomethyl group, a 1-sulfonamidoethyl group, a 2-sulfonamidoethyl group, a 1-methyl-2-sulfonamidoethyl group, or a 3-sulfonamidopropyl group), an acylamino-substituted alkyl group (e.g., an acylaminomethyl group, a 1-acylaminoethyl group, a 2-acylaminoethyl group, a 1-methyl-2-acylaminoethyl group, or a 3-acylamino-propyl group), a sulfonamido-substituted phenylalkyl group (e.g., a p-sulfonamidophenylmethyl group, a p-sulfonamidophenylethyl group, a 1-(p-sulfonamidophenyl)ethyl group, or a p-sulfonamidophenylpropyl group), an acylamino-substituted phenylalkyl group (e.g., a p-acylaminophenylmethyl group, a p-acylaminophenylethyl group, a 1-(p-acylaminophenyl)- ethyl group, or a p-acylaminophenyl group), an alkyl sulfonyl-substituted alkyl group (e.g., a 2-dodecylsulfonyl ethyl group, a 1-methyl-2-pentadecylsulfonylethyl group, or am octadecylsulfonylpropyl group), a phenylsulfonyl-substituted alkyl group (e.g., a 3-(2-butyl-5-octylphenylsulfonyl)propyl group, or a 2-(4-dodecyloxyphenylsulfonyl)ethyl group); an unsubstituted alkyl group such as a methyl group, an ethyl group, a hexyl group, or a dodecyl group; a substituted aryl group such as a sulfonamidophenyl group, an acylaminophenyl group, an alkoxyphenyl group, an aryloxyphenyl group, a substituted-alkylphenyl group, a sulfonamidonaphthyl group, or an acylaminonaphthyl group: an unsubstituted aryl group such as a phenyl group, or a naphthyl group: an alkylthio group such as a methylthio group, an octylthio group, a tetradecylthio group, a 2-phenoxyethylthio group, a 3-phenoxypropylthio group, or a 3-(4-t-butylphenoxy)propylthio group: an arylthio group such as a phenylthio group, a 2-butoxy-5-t-octylphenylthio group, a 3-pentadecylphenylthio group, a 2-carboxyphenylthio group, or a 4-tetradecanamidophenylthio group: or a heterocyclic thio group such as a 2-benzothiazolylthio group, a 2,4-diphenoxy-1,3,5-triazole-6- thio group, or a 2-pyridylthio group. Of these groups, substituted alkyl groups and substituted aryl groups, especially substituted alkyl groups, are preferred over others. X represents a group linked through a nitrogen atom (e.g., a benzenesulfonamido group, a N-ethyltoluenesulfonamido group, a heptafluorobutanamido group, a 2,3,4,5,6-pentafluorobenzamido group, an octanesulfonamido group, a p-cyanophenylureido group, a N,N.diethylsulfamoylamino group, a 1-piperidyl group, a 5,5-dimethyl-2,4-dioxo-3-oxazolidinyl group, a 1-benzylethoxy-3-hydantoinyl group, a 2N-1,1-dioxo-3(2H)-oxo-1,2-benzoisothiazolyl group, a 2-oxo-1,2-dihydro-1-pyridinyl group, an imidazolyl group, a pyrazolyl group, a 3,5-diethyl-1,2,4-triazole-1-yl group, a 5- or 6-bromobenzotriazole 1-yl group, a 5-methyl-1,2,3,4-tetrazole-1-yl group, or a benzimidazolyl group), or a group linked through a sulfur atom (e.g. a phenylthio group, a 2-carboxyphenylthio group, a 2-methoxy-5-t-octylphenylthio group, a 4-methanesulfonylphenylthio group, a 4-octanesulfonamidophenylthio group, a 2-cyanoethylthio group, a 1-ethoxycarbonyltridecylthio group, a 5-phenyl-2,3,4,5- tetrazolythio group, or a 2-benzothiazolyl group), When R₁ , R₂, R'₂, or X is a divalent group and, thus, the coupler (I) or (II) forms a bis compound, then R₁, R₂ or R'₂ represents a substituted or unsubstututed alkylene group (e.g., a methylene group, an ethylene group, a 1,10-decylene group, or -CH₂CH₂-O-CH₂CH₂-), or a substituted or unsubstituted phenylene group (e.g., a 1,4-phenylene group, a 1,3-phenylene group or and X represents a divalent group obtained by converting any of the above-cited monovalent groups into the corresponding divalent group at a proper position. When the coupler represented by the formula (I) or (II) constitutes a part of a vinyl monomer, a linkage group represented by R₁, R₂, or R'₂ includes groups formed by connecting some groups selected from substituted or unsubstituted alkylene groups (e.g., a methylene group, ethylene group, a l,l0-decylene group or a -CH₂CH₂OCH₂CH₂-), substituted or unsubstituted phenylene groups (e.g., a l,4-phenylene group, a l,3-phenylene group or -NHCO-, -CONH-, -O-, -OCO-, and aralkylene groups Suitable examples of such linkage groups include In addition to the group derived from the coupler of the formula (I) or (II), the vinyl group may further have a substituent group. Suitable substituent groups include a hydrogen atom, a chlorine atom, and a lower alkyl group containing l to 4 carbon atoms (e.g., a methyl group or an ethyl group). A monomer having a moiety represented by the general formula (I) or (II) may form a copolymer together with a non-color-forming ethylenic monomer which is not coupled with an oxidation product of an aromatic primary amine developing agent. Suitable examples of non-color-forming ethylenic monomers which are not coupled with an oxidation product of an aromatic primary amine developing agent, are acrylic acid, α-chloroacrylic acid, α-alkylacrylic acids (e.g., methacrylic acid), esters and amides derived from acrylic acids as described above (e.g., acrylamide, n-butylacrylamide, t-butylacrylamide, diacetoneacrylamide, methacrylamide, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and β-hydroxy methacrylate), methylenebisacrylamide, vinyl esters (e.g., vinyl acetate, vinyl propionate, and vinyl laurate), acrylonitrile, methacrylonitrile, aromatic vinyl compounds (e.g., styrene and its derivatives, vinyltoluene, divinylbenzene, vinylacetophenone, and sulfostyrene), itaconic acid, citraconic acid, crotonic acid, vinylidene chloride, vinyl alkyl ethers (e.g., vinyl ethyl ether), maleic acid, maleic anhydride, maleic acid esters, N-vinyl-2-pyrrolidone, N-vinylpyridine and 2- and 4-vinylpyridines. These non-color-forming ethylenic unsaturated monomers can be used in combination with two or more thereof. For example, a combination of n-butyl acrylate with methyl acrylate, of styrene with methacrylic acid, of methacrylic acid with acrylamide or of methyl acrylate with diacetoneacrylamide can be employed. As well known in the field of polymer color couplers, non-color-forming ethylenic unsaturated monomers to be copolymerized with water-insoluble solid monomer couplers can be selected to exert a favorable influence upon the physical properties and/or the chemical properties of the resulting copolymers, such as solubility, compatibility with binders of photographic colloidal compositions, e.g., gelatin, flexibility or thermal stability. The polymer couplers which can be used in the process of the present invention may be either water-soluble or water-insoluble. However, particularly preferred are polymer coupler latexes. Specific examples of typical magenta couplers which can be used in the process of the present invention are illustrated below. Unless otherwise indicated, all fractions of constituent monomers in the polymer couplers instanced below are by weight. A general process for synthesizing the couplers used in the process of the present invention is described below. Some of the inventors have disclosed in Japanese Patent Application (OPI) No. 197688/85 a process for synthesizing 1H-pyrazolo-[1,5-b]-1,2,4-triazoles which have a hydrogen atom or an alkyl group at the 6-position. The couplers of the present invention (formula (I)) can be synthesized in basically the same manner as those described above except that different starting materials are used. The synthesis scheme is illustrated below. Synthesis Scheme In the above scheme, R₁, R₂ and X have the same meanings as in the formula (I), respectively; and R' represents an alkyl group or an aryl group. The substituent X may be introduced at the start as shown above, or the synthesis may be conducted using the compound wherein X is a hydrogen atom as a starting material and various substituents for X may be introduced after synthesis of the skeleton as described hereinafter. The 1H-pyrazolo[5,1-c]-1,2,4-triazole couplers (formula (II)) can be synthesized using 3-alkoxy (or aryloxy)-5-hydrazinopyrazoles as a starting material according to the method described in Japanese Patent Publication No. 30895/73. The polymer couplers can be synthesized using a solution polymerization process or an emulsion polymerization process. The solution polymerization can be carried out using the processes described in U.S. Patent 3,451,820 and Japanese Patent Application (OPI) No. 28745/83. Specifically, a monomer coupler having the moiety represented by formula (I) and a non-color-forming ethylenic monomer (e.g., acrylic acid, α-chloroacrylic acid, alacrylic acid such as methacrylic acid, or an ester or amide derived from such an acrylic acid (e.g., acrylamide, n-butyl acrylamide, n-butyl methacrylate, methyl methacrylate or ethyl methacrylate)) are dissolved in or mixed with a soluble organic solvent (e.g., dioxane or methyl cellosolve) in an appropriate ratio, and polymerization can be initiated at a proper temperature (about 30 to 100°C) through formation of free radicals by applying thereto a physical means such as UV irradiation or high energy irradiation, or by applying chemical means such as use of initiators (e.g., persulfates, hydrogen peroxide, benzoyl peroxide or azobisalkylnitriles). After completion of the polymerization reaction, the polymer can be isolated by extracting the product into an organic organic solvent, concentrating the product, or pouring the product into water. On the other hand, the emulsion polymerization can be effected using the method described in U.S. Patent 3,370,952. A general process for introducing a coupling split-off group is described below. (1) Process for linking a nitrogen atom : Linking a nitrogen atom is divided roughly into three groups. Processes falling into the first group involve, as described in U.S. Patent 3,419,391, nitrosifying the coupling active site of a coupler with an appropriate nitrosifying agent, reducing the nitroso group by a suitable process (for example, a hydrogenation process using a catalyst like Pd-on-carbon or a chemical reduction process using, for example, stannous chloride) and then allowing the resulting 7-amino compound to react with a halide to yield predominantly the amide compound. Processes falling into the second group involve, as described in U.S. Patent 3,725,067, halogenating the 7-position of a coupler with an appropriate halogenating agent such as sulfuryl chloride, chlorine gas, bromine, N-chlorosuccinimide or N-bromosuccinimide, and then replacing the halogen with a nitrogen-containing hetero ring in the presence of an appropriate base catalyst such as triethylamine, sodium hydroxide, diazabicyclo[2,2,2]octane or anhydrous potassium carbonate, according to the process described in Japanese Patent Publication No. 45135/81, thus the coupler which is linked to a nitrogen atom at the 7-position being synthesized. Of couplers to which an oxygen atom is linked, those linking to a phenoxy group at the 7-position can also be synthesized by the processes falling into this group. Processes falling into the third group are effective in introducing a 6π- or 10π-electron system aromatic nitrogen-containing hetero ring to a coupler at the 7-position and involve, as described in Japanese Patent Publication No. 36577/82, adding 2 moles or more of a 6π- or 10π-electron system aromatic nitrogen-containing hetero ring to 1 mole of a 7-halogenated coupler synthesized in the course of the second group process described above and heating the mixture at a temperature of from 50°C to 150°C without using any solvent, or heating it at a temperature of from 30°C to 150°C in an aprotic polar solvent such as dimethylformamide, sulfolane or hexamethylphosphotriamide, to introduce the aromatic nitrogen-containing heterocyclic group to the 7-position of the coupler via the nitrogen atom. (2) Process for linking a sulfur atom : Couplers substituted by an aromatic mercapto or heterocyclic mercapto group at the 7-position can be synthesized using the process described in U.S. Patent 3,227,554, which involves dissolving an arylmercaptane, a heterocyclic mercaptane, or a disulfide corresponding thereto in a halogenated hydrocarbon solvent, converting the mercaptane or disulfide into a sulfenyl chloride with chlorine or sulfuryl chloride, and then adding the sulfenyl chloride a 4-equivalent coupler dissolved in an aprotic solvent. As for the processes of introducing an alkylmercapto group to the 7-position of a coupler, the process described in U.S. Patent 4,264,723 which comprises introducing an mercapto group to the coupling active site of a coupler and allowing a halide to act on the mercapto group, and a one-step process using S-(alkylthio)isothioureas or hydrochlorides (or hydrobromides) are employed effectively. SYNTHESIS EXAMPLE 5.6 g (0.0095 mole) of 2-butoxy-5-t-octyl disulfide was dissolved in 20 ml of dichloromethane. 1.3 g (0.0095 mole) of sulfuryl chloride was added to the solution at room temperature, and the mixture was stirred for 30 min, followed by removal of the solvent using an evaporator. Thus, 2-butoxy-5-octylsulfenyl chloride was obtained. It was dissolved in 10 ml of dichloromethane, and a solution containing 10.6 g (0.0189 mole) of (VII) dissolved in 40 ml of DMF (dimethylformamide) was added to the solution at room temperature. After stirring at a temperature of 42°C to 44°C for 1 h, the mixture was extracted with ethyl acetate. The extract was dried, concentrated, and purified by silica gel column chromatography to give 5.6 g (yield: 70%) of illustrative Coupler (1) in a powder form. Mass Analysis (FD): 854 (M⁺) Elemental Analysis: Magenta dye images produced from the magenta couplers to be employed in the process of the present invention are enhanced in fastness to light by a combined use with color image stabilizers represented by the following formula: wherein R₁₀ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group; R₁₁, R₁₂, R₁₄, and R₁₅ each represents a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, an alkoxy group, an acylamino group, an alkoxycarbonyl group, or a sulfonamido group; and R₁₃ represents an alkyl group, a hydroxyl group, an aryl group, or an alkoxy group, provided that R₁₀ and R₁₁ may combine with each other to form a 5- or 6-membered ring or a methylenedioxy ring, and that R₁₃ and R₁₄ may combine with each other to form a 5-membered hydrocarbon ring. These compounds include those described in U.S. Patents 3,935,016, 3,982,944 and 4,254,216; Japanese Patent Application (OPI) Nos. 21004/80 and 145530/79; British Patent Application Nos. 2,077,455A and 2,062,888A; U.S. Patents 3,764,337, 3,432,300, 3,574,627 and 3,573,050; Japanese Patent Application (OPI) Nos. 152225/77, 20327/78, 17729/78 and 6321/80; British Patent 1,347,556; British Patent Application No. 2,066,975A; Japanese Patent Publication Nos. 12337/79 and 31625/73; U.S. Patent 3,700,455; and Japanese Patent Application (OPI) No. 90155/86. In accordance with a preferred embodiment of the present invention, the couplers used in the process of the present invention are incorporated in a silver halide color photographic material. The couplers may be incorporated in a light-sensitive material or may be added to a color developing bath. A suitable content of the coupler in the light-sensitive material ranges from 2 x 10⁻³ mole to 5 x 10⁻¹ mole, preferably from 1 x 10⁻² mole to 5 x 10⁻¹ mole, per mole of silver halide. When the coupler is a polymeric coupler, its amount is adjusted such that the amount of the color-forming moiety falls into the above-described range. A suitable amount of the coupler to be added to a color developing agent ranges from 0.001 mole to 0.1 mole, preferably from 0.01 mole to 0.05 mole, per l of the bath containing the same. The pyrazoloazole couplers of the process of the present invention can be introduced into a light-sensitive material using various known methods of dispersing. For instance, the dispersion can be effected by a solid dispersion method, an alkaline dispersion method, preferably a latex dispersion method, and more preferably an oil-in-water dispersion method. In the oil-in-water dispersion method, couplers are dissolved in either a high boiling organic solvent having a boiling point of 175°C or above or a so-called auxiliary solvent having a low boiling point, or in a mixture of these solvents and then dispersed finely into an aqueous medium like water or an aqueous gelatin solution in the presence of a surface active agent. Suitable examples of high boiling organic solvents are described for example, in U.S. Patent 2,322,027. The dispersion may be accompanied by phase inversion. Further, the auxiliary solvent used may be removed from the dispersion or decreased in content therein through distillation, noodle washing or ultrafiltration, if desired, in preference to coating of the dispersion. Specific examples of high boiling organic solvents which can be used include phthalic acid esters (e.g., dibutyl phthalate, dicyclohexyl phthalate, di-2-ethylhexyl phthalate or decyl phthalate), phosphoric or phosphonic acid esters (e.g., triphenyl phosphate, tricresyl phosphate, 2-ethylhexyldiphenyl phosphate, tricyclohexyl phosphate, tri-2-ethylhexyl phosphate, tridecyl phosphate, tributoxyethyl phosphate, trichloropropyl phosphate or di-2-ethylhexylphenyl phosphate), benzoic acid esters (e.g., 2-ethylhexyl benzoate, dodecyl benzoate, or 2-ethylhexyl-p-hydroxy benzoate), amides (e.g. diethyldodecanamide or N-tetradecylpyrrolidone), alcohols and phenols (e.g., isostearyl alcohol or 2,4-di-tert-amylphenol), aliphatic carboxylic acid esters (e.g., dioctyl azelate, glycerol tributyrate, isostearyl lactate or trioctyl citrate), aniline derivatives (e.g., N,N-dibutyl-2-butoxy-5-tertoctylaniline), hydrocarbons (e.g., paraffins, dodecylbenzene or diisopropylnaphthalene). As auxiliary solvents organic solvents having a boiling point of from about 30°C or more, preferably from 50°C to about 160°C, can be used, with typical examples including ethyl acetate, butyl acetate, ethyl propionate, methyl ethyl ketone, cyclohexanone, 2-ethoxyethyl acetate and dimethylformamide. Processes and effects of the latex dispersion method, and specific examples of latexes are described, for example, in U.S. Patent 4,199,363 and German Patent Application (OLS) Nos. 2,541,274 and 2,541,363. Silver halide emulsions which can be employed in the process of the present invention include not only a silver chloride emulsion and a silver bromide emulsion but also mixed silver halide emulsions. Typical examples of mixed silver halides which can be used include silver chlorobromide, silver chloroiodobromide and silver iodobromide. Of these silver halides, silver chloroiodobromide, silver iodochloride, or silver iodobromide each having an iodide content of 3 mole% or less, silver chloride, silver bromide, and silver chlorobromide are more preferred. The interior and the surface of the silver halide grain may differ, the silver halide grain may have a multiphase structure with epitaxial faces, or the silver halide grain may be uniform throughout. The silver halide grains of the above-described kinds may be present as a mixture. A mean grain size of the silver halide grains employed in the process of the present invention (the grain size as used herein refers to a grain diameter in case of grains which are spherical or approximately spherical in shape, while it refers to an edge length in case of cubic grains, and in both cases, it is represented by a mean value based on the projected area of the grains) ranges preferably from 0.1 µm to 2 µm, particularly preferably from 0.15 µm to 1 µm. The distribution of the grain size may be either narrow or broad. In the present invention, a so-called monodispersed silver halide emulsion having a narrow grain size distribution such that at least 90%, preferably at least 95%, of the grains fall within the range of ±40% of the number or weight average grain size can be used. In order to satisfy the gradation aimed at by the light-sensitive material, monodispersed silver halide emulsions having substantially the same color sensitivity but differing in grain size can be coated in a single layer as a mixture, or they can be coated separately in a multilayer. Also, two or more polydispersed silver halide emulsions or a combination of monodispersed and polydispersed emulsions may be coated as a mixture or separately in a multilayer. The silver halide grains to be employed in the process of the present invention may have a regular crystal form such as that of a cube, an octahedron, a dodecahedron, or a tetradecahedron, or an irregular crystal form, such as that of the sphere. Also, the grains may have a composite form of these crystal forms. Moreover, the grains may have a tabular form in which a grain diameter is greater than a grain thickness by a factor of 5 or more, particularly 8 or more. Emulsions in which such tabular grains account for 50% or more of the total projected area of the grains may be employed in the process of this invention. Emulsions which contain silver halide grains having various kinds of crystal forms as a mixture may be employed. These various kinds of emulsions may be either those which form a latent image predominantly at the surface of the grain (surface latent image type) or those which mainly form a latent image inside the grains (internal latent image type). These photographic emulsions can be prepared using various methods as described, e.g., in P. Grafkides, Chimie et Physique Photographique, Paul Montel, Paris (1967), G.F. Duffin, Photographic Emulsion Chemistry, The Focal Press, London (1966), V.L. Zelikman et al, Making and Coating Photographic Emulsion, The Focal Press, London (1966), so on. More specifically, any processes, e.g., the acid process, the neutral process or the ammoniacal process can be employed. Also, a method in which silver halide grains are produced in the presence of excess silver ions (the so-called reverse mixing method) can be employed. Moreover, the so-called controlled double jet method in which the pAg of the liquid phase where silver halide grains are to be precipitated is maintained constant may be employed. According to this method, silver halide emulsions having a regular crystal form and an almost uniform grain size can be obtained. The emulsions used in the process of the present invention are, in general, those that are subjected to physical ripening, chemical ripening and spectral sensitization. Additives used in these steps are described in Research Disclosure, No. 17643 and ibid., No. 18716, and the relevant parts therein are listed in the following Table. Known photographic additives which can be used in the process of the present invention are also described in the two Research Disclosure references, and the relevant parts therein are also listed in the following Table. Various color couplers may be used in the process of the present invention, and specific examples thereof are described in the patent specifications referred to in the aforesaid Research Disclosure, No. 17643, VII-C through G. Important dye-forming couplers are those capable of forming three primary colors (of yellow, magenta, and cyan) in a subtractive color process by color development, and specific examples of non-diffusible four-equivalent or two-equivalent couplers which may be used in the present invention are described in the patent specifications referred to in Research Disclosure, No. 17643, VII-C and D. In addition, other couplers as mentioned below may also preferably be used in the process of the present invention. Typical examples of yellow couplers which may be used in the process of the present invention are hydrophobic acylacetamide type couplers having a ballast group. Specific examples thereof are described, for example, in U.S. Patents 2,407,210, 2,875,057, and 3,265,506. Two-equivalent yellow couplers are particularly preferably used in the process of the present invention; and typical examples thereof are oxygen atom-releasing type yellow couplers as described in U.S. Patents 3,408,194, 3,447,928, 3,933,501, and 4,022,620; and nitrogen atom-releasing type yellow couplers as described in Japanese Patent Publication No. 10739/83, U.S. Patents 4,401,752 and 4,326,024, Research Disclosure, No. 18053 (April, 1979), British Patent 1,425,020, and German Patent Application (OLS) Nos. 2,219,917, 2,261,361, 2,329,587, and 2,433,812. α-Pivaloylacetanilide type couplers are good in fastness, especially to light, of the formed dyes; and, on the other hand, α-benzoylacetanilide type couplers are high in color density of the formed dyes. Magenta couplers which may be used in combination with the pyrazoloazole type coupler in the process of the present invention are ballast group-containing hydrophobic indazolone type or cyanoacetyl type couplers, preferably 5-pyrazolone type or pyrazoloazole type couplers. Among the 5-pyrazolone type couplers, those whose 3-position is substituted by an arylamino group or an acylamino group are preferred because of hue and color density of the formed dyes. Typical examples of these couplers are described in U.S. Patents 2,311,082, 2,343,703, 2,600,788, 2,908,573, 3,062,653, 3,152,896, and 3,936,015. Regarding the split-off group of the two-equivalent 5-pyrazolone type couplers, nitrogen atom-releasing groups as described in U.S. Patent 4,310,619 and arylthio groups as described in U.S. Patent 4,351,897 are especially preferred. In addition, ballast group-containing 5-pyrazolone type couplers as described in European Patent 73,636 are preferred because they provide a high color density. As cyan couplers which can be used in the process of the present invention, hydrophobic and diffusion-resistant naphthol type and phenol type couplers are exemplified. Typical examples thereof include naphthol type couplers as described in U.S. Patent 2,474,293 and preferably oxygen atom-releasing type two-equivalent naphthol type couplers as described in U.S. Patents 4,052,212, 4,146,396, 4,228,233 and 4,296,200, etc. Specific examples of phenol type couplers are described in U.S. Patents 2,369,929, 2,801,171, 2,772,162 and 2,895,826. Cyan couplers capable of forming cyan dyes fast to humidity and temperature are preferably used in the process of the present invention. Typical examples thereof include phenol type cyan couplers having an alkyl group more than a methyl group at the meta-position of the phenol nucleus as described in U.S. Patent 3,772,002, 2,5-diacylamino-substituted phenol type couplers as described in U.S. Patents 2,772,162, 3,758,308, 4,126,396, 4,334,011 and 4,327,173, West German Patent Application (OLS) No. 3,329,729, and European Patent 121,365, phenol type couplers having a phenylureido group at the 2-position thereof and an acylamino group at the 5-position thereof as described in U.S. Patents 3,446,622, 4,333,999, 4,451,559 and 4,427,767. Further, cyan couplers of the naphthol type having a sulfonamido group or an amido group, at the 5-position thereof as described in Japanese Patent Application (OPI) Nos. 237448/85, 153640/86 and 145557/86 are also preferably employed in the process of the present invention because of excellent fastness of color images formed therefrom. Further, couplers capable of forming appropriately diffusible dyes can be used together in order to improve the graininess. Specific examples of such types of magenta couplers are described in U.S. Patent 4,366,237 and British Patent 2,125,570, and those of yellow, magenta and cyan couplers are described in European Patent 96,570 and West German Patent Application (OLS) No. 3,234,533. Dye forming couplers and the above described special couplers may form polymers including dimers or more. Typical examples of polymerized dye forming couplers are described in U.S. Patents 3,451,820 and 4,080,211. Specific examples of polymerized magenta couplers are described in British Patent 2,102,173 and U.S. Patent 4,367,282. Couplers capable of releasing a photographically useful residue during the course of coupling can also be preferably employed in the process of the present invention. Specific examples of useful DIR couplers capable of releasing a development inhibitor are described in the patents cited in Research Disclosure, No. 17643 (December, 1978), "VII-F" as mentioned above. The color photographic materials used in the process of the present invention may be developed by means of a conventional developing means as described, for example, in the aforesaid Research Disclosure, NO. 17643, pp. 28-29 and ibid., No. 18716, page 651, from left-hand column to right-hand column. After development and bleach-fixing or fixing, the color photographic light-sensitive material used in the present invention is generally subjected to washing or stabilization. The washing step is, in general, carried out using two or more tanks according to the countercurrent washing method for the purpose of saving water. As a typical example of the stabilizing step, mention may be made of a multistage countercurrent stabilization processing which is to be carried out in place of the washing step, as described in Japanese Patent Application (OPI) No. 8543/82. In the processing of the present invention, a countercurrent bath having 2 to 9 tanks is required. To the stabilizing bath used in the present invention are added various kinds of compounds in order to stabilize the developed images. Typical examples of such additives include various buffering agents for adjusting the pH of the film to a proper value (ranging, e.g., from 3 to 8), such as those prepared by combining properly acids and alkalis selecting from borates, metaborates, borax, phosphates, carbonates, potassium hydroxide, sodium hydroxide, aqueous ammonia, monocarboxylic acids, dicarboxylic acids, polycarboxylic acids, and formaldehyde. The stabilizing bath may further contain a water softener (e.g., inorganic phosphoric acids, aminopolycarboxylic acids, organic phosphoric acids, aminopolyphosphonic acids or phosphonocarboxylic acids), a fertilizer (e.g., benzisothiazolinone, isothiazolone, 4-thiazolinebenzimidazole or halogenated phenols), a surface active agent, a fluorescent whitening agent, a hardener, and various kinds of additives, if desired. Two or more kinds of compounds may be used for the same purpose or different purposes. In addition, it is desired that various ammonium salts such as ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium phosphate, ammonium sulfite or ammonium thiosulfate, are added to the stabilizing bath in order to control the pH of the processed film. The process of the present invention can be applied to various kinds of color photographic materials. Representatives of such materials are color negative films for general use or motion picture use, color reversal films for slide use or television use, color paper, color positive films or color reversal paper. The present invention is illustrated in greater detail by reference to the following examples. EXAMPLE 1 17 ml of tri(2-ethylhexyl) phosphate and 25 ml of ethyl acetate were added to 14,3 g of Coupler (1) as a magenta coupler, and the mixture was heated for dissolution. The solution was added to 100 ml of an aqueous solution containing 10 g of gelatin and 1.0 g of sodium dodecylbenzenesulfonate, followed by stirring at an elevated temperature to prepare a finely emulsified dispersion. The whole amount of the emulsion dispersion was added to 100 g of a silver chlorobromide emulsion having a bromide content of 50 mole% (containing 6.5 g of silver), and 10 ml of a 2% aqueous solution of 2,4-dihydroxy-6-chloro-s-triazine sodium salt was further added thereto as a hardener. The thus prepared composition was coated on a paper support laminated with polyethylene on both the sides thereof in such an amount that the silver coverage was 200 mg/m². A gelatin layer was provided on the coated layer to prepare a sample. This sample is referred to as Sample A. In addition, a comparative sample was prepared in the same manner as described above except that 8.9 g of the following compound was used as the magenta coupler and that tri(2-ethylhexyl) phosphate was used in an amount of 18 ml instead of 20 ml. Sample A and the comparative sample were subjected to 1000 C.M.S. wedge exposure and then processed using the following processing solutions. Each of the thus processed samples provided a distinct magenta color image of high saturation. Photographic characteristics of these color images obtained were examined, and the results are shown below. It can be seen from the above results that the coupler used in the present invention is superior in both sensitivity and gradation to the coupler having an alkyl group at the 6-position. This is attributable to introduction of an alkoxy group or an aryloxy group at the 6-position, whereby the coupling activity is enhanced and the color-forming efficiency is improved. EXAMPLE 2 As described in Table 2, a first layer (undermost layer) to a seventh layer (uppermost layer) were coated in sequence on a paper support laminated with polyethylene on both sides thereof to prepare color photographic materials B and C. The coating compositions used for forming each third layer in which an emulsion dispersion of magenta coupler and a silver halide emulsion were contained were prepared in the same manner as in Example 1. Table 2 Support Paper support laminated with polyethylene on both sides thereof 1st Layer Blue-sensitive silver chlorobromide emulsion (Br content: 80 mol%, Ag coverage: 350 mg/m²), Gelatin (coverage: 1500 mg/m²), Yellow coupler (*1) (coverage: 500 mg/m²), Solvent (*2) (coverage: 400 mg/m²) 2nd Layer Gelatin (coverage: 1100 mg/m²), Color-mixing inhibitor (*3) (coverage: 200 mg/m²), Solvent (*4) (coverage: 100 mg/m²) 3rd Layer Green-sensitive silver chlorobromide emulsion (Br content: 50 mol%, Ag coverage: 180 mg/m²), Magenta coupler (*5) (coverage: 3.4x10⁻⁴ mole/ m²), Solvent (*6) (coverage: 510 mg/m² in Sample E, 480 mg/m² in Sample F, and 410 mg/m² in Sample G) 4th Layer Gelatin (coverage: 1600 mg/m²), UV light absorbent (*7) (coverage: 700 mg/m²), Color-mixing inhibitor (*3) (coverage: 200 mg/m²), Solvent (*4) (coverage: 300 mg/m²) 5th Layer Red-sensitive silver chlorobromide emulsion (Br content: 50 mol%, Ag coverage: 300 mg/m²), Gelatin (coverage: 1200 mg/m²), cyan coupler (*8) (coverage: 400 mg/m²), Solvent (*4) (coverage: 250 mg/m²) 6th Layer Gelatin (coverage: 1000 mg/m²), UV light absorbent (*7) (coverage: 360 mg/m²), Solvent (*4) (coverage: 120 mg/m²) 7th Layer Gelatin (coverage: 1600 mg/m²) *1 Yellow coupler: α-Pivaloyl-α-(2,4-dioxo-5,5'-dimethyloxazolidine-3-yl)-2-chloro-5-[α-(2,4-di-tert-pentylphenoxy)butanamido]-acetanilide *2 Solvent: Dioctylbutyl phosphate *3 Color-mixing inhibitor: 2,5-Dioctylhydroquinone *4 Solvent: Dibutyl phthalate *5 Magenta coupler: Sample B, Coupler (15) Sample C, Comparative compound used in Example 1 *6 Solvent Tri(2-ethylhexyl) phosphate *7 UV light absorbent: 2-(2-Hydroxy-3-sec-butyl-5-tert-butylphenyl)benzotriazole *8 Cyan coupler: 2-[α-(2,4-Di-tert-pentylphenoxy)tutanamido]-4,6-dichloro-5-methylphenol B and C were exposed in the same manner as in Example 1 through a B-G-R three-color separation filter and then processed in the same manner as in Example 1 except that the color development time employed was 2 min, 3 min and 30 s, or 6 min. Changes in photographic characteristics caused by changing the color development time are shown in Table 3. The foregoing data show that in the multilayered multicolor photographic material, less dependence of development time upon sensitivity, gradation and maximum density was observed in the sample containing the coupler used in the present invention as compared with the sample containing the coupler of 6-positioned methyl type. That is, the couplers of the present invention can contribute to attainment of photographic characteristics with less fluctuation by short-time development. High activity and high color-forming efficiency of the couplers used in the present invention as compared with those of conventional pyrazoloazole couplers are advantageous in designing photographic materials. Thus, the couplers used in the present invention have excellent properties. EXAMPLE 3 20 ml of tri(2-ethylhexyl) phosphate and 25 ml of ethyl acetate were added to 10.0 g (16.8 mmol) of Coupler (2) as a magenta coupler, and the mixture was heated for dissolution. The solution was added to 100 ml of an aqueous solution containing 10 g of gelatin and 1.0 g of sodium dodecylbenzenesulfonate, followed by stirring at an elevated temperature to prepare a finely emulsified dispersion. The whole amount of the emulsion dispersion was added to 100 g of a silver chlorobromide emulsion having a bromide content of 30 mole% (containing 6.5 g of silver), and 10 ml of a 2% aqueous solution of 2,4-dihydroxy-6-chloro-s-triazine sodium salt was further added thereto as a hardener. The thus prepared composition was coated on a paper support laminated with polyethylene on both the sides thereof in such an amount that the silver coverage was 200 mg/m². A gelatin layer was provided on the coated layer to prepare a sample. This sample is referred to as Sample I-(A). Other emulsion dispersions were prepared in the same manner as described above except that the magenta coupler was replaced by equimolar amounts of Couplers (7), (8), (11) (13) and (14) respectively. These emulsion dispersions each was mixed with the same amount of the same silver chlorobromide emulsion as described above and coated on the same support at the same silver coverage as described above. The thus obtained samples were referred to as Sample I-(B) to I-(G), respectively. In addition, Comparative Sample (1) was prepared in the same manner as described above except that 8.9 g (16.8 mmol) of the following Comparative Compound (1): was used as the magenta coupler and that tri(2-ethylhexyl) phosphate was used in an amount of 18 ml instead of 20 ml. In a similar manner, another Comparative Sample (2) was prepared using 8.9 g of the following Comparative Compound (2): These Samples I-(A) to I-(G) and the Comparative Samples (1) and (2) were subjected to 1000 C.M.S. wedge exposure and then processed using the following processing solutions. Each of the thus processed samples provided a distinct magenta color image of high saturation. Photographic characteristics of these, color images obtained were examined, and the results are shown below. In analogy with Example 1, it can be seen from the foregoing data that the couplers used in the present invention have more excellent effects upon any of sensitivity, gradation and color density of the developed image as compared with the coupler having an alkyl group at the 6-position. EXAMPLE 4 On a paper support laminated with polyethylene on both sides thereof were coated the layers described in Table 5 to prepare a multilayered multicolor photographic printing paper. The coating compositions used were prepared in the following manners. Preparation of coating composition for first layer : 10 g of a yellow coupler (a) and 2.1 g of a color image stabilizer (b) were added to and dissolved in a mixture of 10 ml of ethyl acetate and 4.0 ml of a solvent (c). The solution was emulsified and dispersed into 90 ml of a 10% aqueous gelatin solution containing 10 ml of 1% sodium dodecylbenzenesulfonate. Separately, 95 g of a blue-sensitive emulsion was prepared by adding a blue-sensitive dye illustrated below to a silver chlorobromide emulsion (having a bromide content of 50 mol% and containing Ag in an amount of 70 g of per kg of the emulsion) in an amount of 2.25 x 10⁻⁴ mole per mole of silver chlorobromide. The emulsion dispersion and the silver chlorobromide emulsion was mixed with each other, and gelatin was further added thereto in an amount to adjust the concentrations of the ingredients to values set forth in Table 5. Thus, a coating composition for the first layer was prepared. Coating compositions for the second to seventh layers were prepared in a similar manner as described above. In each layer, 1-oxy-3,5-dichloro-s-triazine sodium salt was used as a gelatin hardener. Spectral sensitizers employed in the respective emulsion layers are illustrated below. Blue-sensitive Emulsion Layer : Green-Sensitive Emulsion Layer : Red-Sensitive Emulsion Layer: The following dyes were incorporated in the emulsion layers as their respective irradiation preventing dyes. Green-Sensitive Emulsion Layer: Red-Sensitive Emulsion Layer: The structural formulae of the compounds employed in this example including couplers are illustrated below. (a) Yellow Coupler (b) Color Image Stabilizer (c) Solvent (d) Color-Mixing Preventing Agent (e) Solvent 1:1 (by mole) mixture of and (f) UV Light Absorbent 1:5:3 (by mole) mixture of and (g) Cyan Coupler (h) Color Image Stabilizer 1:3:3 (by mole) mixture of and (i) Solvent 1:2 (by mole) mixture of After balancing the surface tension and the viscosity of the coating compositions for forming the first to seventh layers, the compositions were simultaneously coated to prepare a multilayered silver halide color photographic material. Various coating compositions for the third layer were prepared using the couplers represented by the formula (I) or (II) of the present invention and the comparative couplers as the magenta coupler and changing the formulation variously as shown in Table 6. Using these coating compositions respectively, multilayered color photographic materials were prepared and referred to as Samples II-A to II-G. (j) Color image stabilizer (k) Solvent (ℓ) Solvent (m) Comparative coupler (n) Comparative coupler These silver halide color photographic materials were subjected to wedge exposure in a conventional manner and processed according to the following processing steps using processing solutions having formulations described below. The thus obtained sensitometric samples were examined for photographic characteristics, and the results obtained are shown in Table 7. In the above table, the sensitivity is a relative value, taking the sensitivity of Sample II-A₁ and Sample B attained by l.5 min development as l00 (comparison was carried out using samples having the same volume). The gradation (γ) is expressed in terms of a slope of the characteristic curve in the straight line portion corresponding to the density range of from 0.6 to 2.0. The maximum density means a maximum density of magenta dye image. As can be seen from the data set forth in Table 7, the samples using the coupler of the process of the present invention, Samples II-C to II-G had enhanced sensitivity and improved gradation (γ) and produced high color density of the developed image. EXAMPLE 5 For the purpose of sensitometry evaluation, the samples prepared in Example 4, Samples II-A to II-G, were subjected to wedge exposure in a conventional manner and processed according to the following processing steps using processing solutions having formulations described below. The results obtained are shown in Table 8. In the above table, the sensitivity is a relative value, taking the sensitivity of Samples II-A₁ and II-B attained by 30 s development as l00. The gradation (γ) is expressed in terms of a slope of the characteristic curve in the straight line portion corresponding to the density range of from 0.6 to 2.0. Gamma values in parentheses are slopes of individual straight line portions because image densities did not go up to 2.0 under such conditions. The maximum density means a maximum density of magenta dye image. As can be seen from the data set forth in Table 8, the Samples II-C to II-G in which the couplers of the process of present invention were incorporated had enhanced sensitivity and improved gradation and provided high color density of the developed image. EXAMPLE 6 On a paper support laminated with polyethylene on both sides thereof were coated the layers described below, from the first layer to the twelfth layer, to prepare Sample III-A₁ and Sample III-A₂. Titanium white as a white pigment and a trace amount of ultramarine as a bluish pigment were incorporated in the polyethylene laminated in the side of the first layer. (Composition of Constituent Layers) Ingredients and their respective coverages expressed in terms of g/m² are described below. The coverage of the silver halide is based on silver. Samples III-B to III-F were prepared in the same manner as Sample III-A₁ or III-A₂ except that the comparative magenta coupler (*l5) was replaced by an equimolar amount of each of Couplers (2), (7), (8), (11), and (13). These samples III-A to III-F were subjected to wedge exposure in a conventional manner and then processed according to the following processing steps using processing solutions having the formulations described below. The thus obtained sensitometric samples were examined for photographic characteristics, and the results obtained are shown in Table 9. As can be seen from the data shown in the above table, Samples III-B to III-F in which the couplers of the process of the present invention are employed had improved gradation (γ) and produced high color density of the developed image. EXAMPLE 7 On a triacetate film support were coated the following first to thirteenth layers in this order to prepare Samples IV-A₁ and IV-A₂. First Layer (Antihalation layer) : l5 g of 5-chloro-2-(2-hydroxy-3,5-di-t-butylphenyl)-2H-benzotriazole, 30 g of 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, 35 g of 2-(2-hydroxy-3-sec-butyl-5-t-butylphenyl)-2H-benzotriazole, and l00 g of dodecyl 5-(N,N-diethylamino)-2-benzenesulfonyl-2,4-pentadienoate, which are UV light absorbents, 200 ml of tricresyl phosphate, 200 ml of ethyl acetate, 20 g of sodium dodecylbenzenesulfonate, and a l0% gelatin aqueous solution were stirred at a high speed to prepare an emulsion (referred to as Emulsion (a)). This emulsion was mixed with l0% gelatin, black colloidal silver, water, and coating aids, and the mixture was coated in a dry thickness of 2 µm. Second Layer (Gelatin interlayer) : 2,5-Di-t-octylhydroquinone was dissolved in a mixture of l00 ml of dibutyl phthalate and l00 ml of ethyl acetate. The solution and l kg of a l0% gelatin aqueous solution were stirred at a high speed to prepare an emulsion (referred to as Emulsion (b)). A 2 kg portion of Emulsion (b) was mixed with a l.5 kg portion of l0% gelatin, and the mixture was coated in a dry thickness of l µm. Third Layer (Red-sensitive emulsion layer having low sensitivity) : l0.0 g of 2-(heptafluorobutylamido)-5-[2'-(2",4"-di-t-aminophenoxy)butylamino]phenol (cyan coupler) was dissolved in a mixture of l00 ml of tricresyl phosphate and l00 ml of ethyl acetate, and the solution was mixed with l kg of a l0% gelatin aqueous solution with high-speed stirring to prepare an emulsion (referred to as Emulsion (c)). A 500 g portion of Emulsion (c) was mixed with a l kg portion of a red-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having an iodide content of 4 mol%). The mixture was coated in a dry thickness of l µm (silver coverage: 0.5 g/m²). Fourth Layer (Red-sensitive emulsion layer having high sensitivity) Emulsion (c) was mixed with a l kg portion of a red-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having an iodide content of 2.5 mol%), and the mixture was coated in a dry thickness of 2.5 µm (silver coverage: 0.8 g/m²). Fifth Layer (Interlayer) : Emulsion (b) was mixed with a l kg portion of l0% gelatin, and the mixture was coated in a dry thickness of l µm. Sixth Layer (Green-sensitive emulsion layer having low sensitivity) : An emulsion was prepared in the same manner as the emulsion for the 3rd layer except that Comparative Magenta Coupler (l) (in Sample IV-A₁) or Comparative Magenta Coupler (2) (in Sample IV-A₂) was used in place of the cyan coupler. This emulsion was referred to as Emulsion (d). Comparative Magenta Coupler (l) Comparative Magenta Coupler (2) A 300 g portion of Emulsion (d) was mixed with a l kg portion of a green-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having an iodide content of 3 mol%), and the mixture was coated in a dry thickness of 2.0 µm (silver coverage: 0.7 g/m²). Seventh Layer (Green-sensitive emulsion layer having high sensitivity) : A l000 g portion of Emulsion (d) was mixed with a l kg portion of a green-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having an iodide content of 2.5 mol%), and the mixture was coated in a dry thickness of 2.0 µm (silver coverage: 0.7 g/m²). Eighth Layer (Gelatin interlayer) : A l kg portion of Emulsion (b) was mixed with a l kg portion of l0% gelatin, and the mixture was coated in a dry thickness of 0.5 µm. Ninth Layer (Yellow filter layer) : An emulsion containing yellow colloidal silver was coated in a dry thickness of l µm. Tenth Layer (Blue-sensitive emulsion layer having low sensitivity) : A l000 g portion of an emulsion which had been prepared in the same manner as the emulsion for the 3rd layer except that an yellow coupler, α-(pivaloyl)-α-(l-benzyl-5-ethoxy-3-hydantoinyl)-2-chloro-5-dodecyloxycarbonylacetoanilide was employed in place of the cyan coupler, which is referred to as Emulsion (e), was mixed with a l kg portion of a blue-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having an iodide content of 2.5 mol%), and the mixture was coated in a dry thickness of l.5 µm (silver coverage: 0.6 g/m²). Eleventh Layer (Blue-sensitive emulsion layer having high sensitivity) : A l000 g portion of Emulsion (e) was mixed with a l kg portion of a blue-sensitive silver iodobromide emulsion (containing 70 g of silver and 60 g of gelatin and having iodide content of 2.5 mol%), and the mixture was coated in a dry thickness of 3 µm (silver coverage: l.l g/m²). Twelfth Layer (Second protective layer) : Emulsion (a) was mixed with l0% gelatin water, and coating aids, and the mixture was coated in a dry thickness of 2 µm. Thirteenth Layer (First protective layer) : A l0% gelatin aqueous solution containing a fine grain emulsion in which the individual grain surfaces were fogged (grain size: 0.06 µm l mol% silver iodobromide emulsion) was so coated as to have a dry thickness of 0.8 micron and a silver coverage of 0.l g/m². In each of these layers, l,4-bis(vinylsulfonylacetamido)ethane as a gelatin hardener and a surface active agent were additionally contained. Samples IV-B to IV-G were prepared in the same manner as the Sample IV-A₁ or IV-A₂ except that Comparative Magenta Coupler (l) or (2) was replaced by an equimolar amount of each of Couplers (2), (7), (8), (11), (13) and (14) respectively. These Samples IV-A to IV-G were exposed through a neutral gray wedge for sensitometry and then subjected to reversal processing steps. Processing solutions having the compositions described below were employed. The thus obtained sensitometric samples were examined for photographic characteristics, and the results obtained are shown in Table l0. As can be seen from the data shown in Table l0, Samples IV-B to IV-G in which the couplers of the process of present invention are employed had improved gradation (γ) and produced high color density of the developed image. EXAMPLE 8 On a triacetyl cellulose film support were coated the layers described below in this order to prepare multilayered multicolor photographic materials (Samples V-A₁ and V-A₂). First Layer (Antihalation layer) : A gelatin layer containing black colloidal silver. Second Layer (Interlayer) : A gelatin layer containing an emulsion dispersion of 2,5-di-t-octylhydroquinone. Third Layer (First red-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of 5 mol% and a silver coverage of l.6 g/m²), 4.5 × l0⁻⁴ mol/mol silver of Sensitizing Dye I, l.5 × l0⁻⁴ mol/mol silver of Sensitizing Dye II, 0.04 mol/mol silver of Coupler EX-l, 0.003 mol/mol silver of Coupler EX-3, and 0.0006 mol/mol silver of Coupler EX-9. Fourth Layer (Second red-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of l0 mol% and a silver coverage of l.4 g/m²), 3 × l0⁻⁴ mol/mol silver of Sensitizing Dye I, l × l0⁻⁴ mol/mol silver of Sensitizing Dye II, 0.002 mol/mol silver of Coupler EX-l, 0.02 mol/mol silver of Coupler EX-2, and 0.00l6 mol/mol of Coupler EX-3. Fifth Layer (Interlayer) : The same layer as the second layer. Sixth Layer (First green-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of 4 mol% and a silver coverage of l.2 g/m²), 5 × l0⁻⁴ mol/mol silver of Sensitizing Dye III, 2 × l0⁻⁴ mol/mol silver of Sensitizing Dye IV, and 0.05 mol/mol silver of Comparative Magenta Coupler (l) or (2). Seventh Layer (Second green-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of 8 mol% and a silver coverage of l.3 g/m²), 3 × l0⁻⁴ mol/mol silver of Sensitizing Dye III, l.2 ;TS l0;S-;S4 mol/mol silver of Sensitizing Dye IV, and 0.0l7 mol/mol silver of Comparative Magenta Coupler (l) or (2). Eighth Layer (Yellow filter layer) : A gelatin layer containing an emulsion dispersion prepared by emulsifying and dispersing yellow colloidal silver and 2,5-di-t-octylhydroquinone into a gelatin aqueous solution. Ninth Layer (First blue-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of 6 mol% and a silver coverage of 0.7 g/m², 0.25 mol,/mol silver of Coupler EX-4, and 0.0l5 mol/mol silver of Coupler EX-5. Tenth Layer (Second blue-sensitive emulsion layer) : A layer containing a silver iodobromide emulsion (having an iodide content of 6 mol% and a silver coverage of 0.6 g/m²) and 0.06 mol/mol silver of Coupler EX-4. Eleventh Layer (First protective layer) : A gelatin layer containing silver iodobromide (having an iodide content of l mol% and a mean grain size of 0.07 micron and a silver coverage of 0.5 g/m²) and an emulsion dispersion of UV Light Absorbent UV-l. Twelfth Layer (Second protective layer) : A gelatin layer containing polymethyl methacrylate particles (having a diameter of about l.5 µm). In addition to the above-described ingredients, Gelatin Hardener H-l and a surface active agent were incorporated in each of the foregoing layers. Structural formulae of the ingredients employed in the foregoing layers are illustrated below. Coupler EX-l Coupler EX-2 Coupler EX-3 Coupler EX-4 Coupler EX-5 Coupler EX-6 Comparative Magenta Coupler (l) (in Sample V-A₁) Comparative Magenta Coupler (2) (in Sample V-A₂) H-l UV-l Sensitizing Dye I Sensitizing Dye II Sensitizing Dye III Sensitizing Dye IV Samples V-B to V-G were prepared in the same manner as Sample V-A₁ or V-A₂ except that Comparative Magenta Coupler (l) or (2) was replaced by an equimolar amount of each of Couplers (2), (7), (8), (11), (13) and (14), respectively. These Samples V-A to V-G were subjected to wedge exposure in a conventional manner and then processed according to the following processing steps using processing solutions having the formulations described below. The photographic processing employed herein included the following steps and was carried out at a temperature of 38°C. Compositions of the processing solutions used were as follows. The thus obtained sensitometric samples were examined for photographic characteristics, and the results obtained are shown in Table ll. As can be seen from the data shown in Table ll, both the sensitivity and gradation (γ) were improved in Samples V-B to V-G wherein the couplers of the process of the present invention are employed, and high color density of the developed image was also obtained therein. From the results described above, it has been proved that in the silver salt color photography, the couplers of the process of the present invention have less dependence of sensitivity, gradation and maximum density upon color development time and can exhibit photographic characteristics with smaller fluctuation by short-time development as compared with the conventional couplers having an alkyl group at the 6-position. As the couplers of the process of the present invention possess higher activity and higher color-forming efficiency as compared with conventional pyrazoloazole couplers, they are advantageous in designing photographic materials. Thus, the couplers of the process of the present invention are found to have excellent properties.

Claims: A process for forming a color image comprising developing a silver halide photographic material using a developer containing an aromatic primary amine in the presence of at least one coupler characterized in that said coupler is represented by the following formula (I) or (II): wherein R₁ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a heterocyclic group; R₂ represents a hydrogen atom or a substituent group; and X represents a split-off group linked through a nitrogen or sulfur atom; wherein R₁ and X have the same meanings as in formula (I), respectively; and R'₂ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, an alkylthiogroup, an arylthio group, or a heterocyclic thio group. The process of claim 1, wherein the substituent group represented by R₂ is a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a cyano group, an alkoxy group, an aryloxy group, an acylamino group, an anilino group, a ureido group, a sulfamoylamino group, an alkylthio group, an arylthio group, an alkoxycarbonylamino group, a sulfonamido group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, or an alkoxycarbonyl group. The process of claim 2, wherein the substituent group represented by R₂ is an alkyl group, an aryl group, an alkylthio group, or an arylthio group. The process of claim 1, wherein the substituent group represented by R₂ is a an alkyl group or an aryl group. The process of claim 1, wherein R'₂ is a substitued alkyl group or a substituted aryl group. The process of claim 5, wherein R'₂ is a substituted alkyl group. The process of claim 1, wherein R₁, R₂, R'₂, or X is a divalent group to form a bis compound, R₁, R₂, or R'₂ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted phenylene group, and X represents a divalent group obtained by converting any of the monovalent groups as recited in claim 1 into a corresponding divalent group at a proper position. The process of claim 1, wherein when the coupler represented by formula (I) or (II) constitutes a part of a vinyl monomer, a linkage group represented by R₁, R₂, or R'₂ includes groups formed by connecting groups selected from a substituted or unsubstituted alkylene group, a substituted or unsubstituted phenylene group, -NHCO-, -CONH-, -O-, -OCO-, and an aralkylene group. The process of claim 1, wherein a monomer having the moiety represented by formula (I) or (II) forms a copolymer together with a non-color-forming ethylenic monomer which is not coupled with an oxidation product of an aromatic primary amine developing agent. The process of claim 1, wherein the coupler represented by formula (I) or (II) is incorporated in the silver halide photographic material. The process of claim 1, wherein the coupler represented by formula (I) or (II) is added to a color developing bath. The process of claim 10, wherein the coupler represented by formula (I) or (II) is added in an amount of from 2 x 10⁻³ mole to 5 x 10⁻¹ mole per mole of the silver halide. The process of claim 12, wherein the coupler represented by formula (I) or (II) is added in an amount of from 1 x 10⁻² mole to 5 x 10⁻¹ mole per mole of the silver halide. The process of claim 11, wherein the coupler represented by formula (I) or (II) is added in an amount of from 0.001 mole to 0.1 mole per liter of the color developing bath. The process of claim 14, wherein the coupler represented by formula (I) or (II) is added in an amount of from 0.01 to 0.05 mole per liter of the color developiing bath. The process of claim 1, wherein said silver halide photographic material is incorporated with a color image stabilizer represented by the following formula: wherein R₁₀ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group; R₁₁, R₁₂, R₁₄, and R₁₅ each represents a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, an alkoxy group, an acylamino group, an alkoxycarbonyl group, or a sulfonamido group; and R₁₃ represents an alkyl group, a hydroxyl group, an aryl group, or an alkoxy group, provided that R₁₀ and R₁₁ may combine with each other to form a 5- or 6-membered ring or a methylenedioxy ring, and that R₁₃ and R₁₄ may combine with each other to form a 5-membered hydrocarbon ring.

Inventors: FURUTACHI, NOBUO FUJI PHOTO FILM CO., LTD., SATO, TADAHISA FUJI PHOTO FILM CO., LTD.
Applicants: FUJI PHOTO FILM CO., LTD.
Application year: 1986
Main classification: G03C7
IPC codes: G03C7