SILVER HALIDE COLOR PHOTOGRAPHIC LIGHT-SENSITIVE MATERIAL

Abstract: A silver halide color photographic light-sensitive material comprising a silver halide emulsion layer containing a cyan coupler represented by the following general formula [I]. The color photo-graphic material is improved in sensitivity, density of cyan image, density losing of cyan image due to processing by a fatigued bleach or bleach-fix solution.

Description: The present invention relates to a silver halide color photographic light-sensitive material, in particular, to a silver halide color photographic light-sensitive material capable of providing a cyan dye image indicating satisfactory spectral absorption properties and free from dye loss, even when treated with a bleaching bath or bleach-fixing bath which has been fatigued through use. A dye image is usually formed in a silver halide color photographic light-sensitive material in the following manner: first, exposed silver halide particles, are reduced by an aromatic primary amine color developing agent; next, the resultant oxidation product of the color developing agent couples with couplers respectively forming yellow, magenta, and cyan dyes. Couplers widely used for forming the cyan dye are phenol cyan couplers and naphthol cyan couplers. The rapid progress in color photography has prompted a drastic increase in the number of color negative films being treated, and the bleaching bath or bleach-fixing bath readily develops fatigue during use. The naphthol compounds conventionally widely used as cyan couplers for color negative films have disadvantages; when such a film is treated with a fatigued bleaching bath or bleach-fixing bath, the cyan dye formed reverts to a leuco base, resulting in dye loss. To solve these problems, cyan couplers having a phenylureide group in the 2-position on a phenol ring have been developed as described in, for example, Japanese Patent Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) Nos. 21139/1972, 65134/1981, 204543/1982, 204544/1982, 204545/1982, 98731/1983 and 187928/1983. This cyan coupler drastically improves the dye loss. However, these cyan couplers have a disadvantage regarding color reproduction: in relation to spectral absorption property, the dyes formed from these couplers, when compared with dyes formed from naphthol couplers, have a maximum absorption wavelength in a relatively shortwave range, thus providing greater absorption in the green range to a shortwave range. Human vision is especially sensitive to green light. Therefore, even a marginal reduction in green absorption contributes to a greater improvement in color reproduction as appreciated by human vision. Thus, further improved cyan couplers are required. EP-A-0175 573 discloses cyan couplers of the following general formula: wherein R¹ is a group having a bulk sufficient to impart diffusion resistance to said coupler; R² and R³ each represent a hydrogen atom or a halogen atom, at least one of R² and R³ being a halogen atom; and Z represents a hydrogen atom or a group eliminable during the coupling reaction with the oxidized product of a color developing agent. The present invention seeks to provide a highly sensitive, silver halide color photographic light-sensitive material capable of forming a cyan image with high color density. The invention also seeks to provide a silver halide color photographic light-sensitive material capable of forming a cyan image free from dye loss even when using a bleaching bath or bleach-fixing bath which has been fatigued in the course of prolonged treatment. The invention further seeks to provide a silver halide color photographic light-sensitive material capable of forming a cyan dye image which has a satisfactory spectral absorption property and of which maximum absorption range is in a comparatively longer wavelength range. In addition, the invention seeks to provide a silver halide color photographic light-sensitive material capable of forming a cyan dye image and capable of being manufactured at relatively low cost. Furthermore, the invention seeks to provide a silver halide color photographic light-sensitive material with excellent dispersion stability and capable of forming a cyan image. According to the present invention there is provided a silver halide color photographic light-sensitive material comprising a silver halide emulsion layer containing a cyan coupler of formula I: General formula [I] (wherein R₁ is substituted or unsubstituted alkyl or substituted or unsubstituted aryl, and Z is a group of formula [II], [III], [IV] or [V]) General formula [II] General formula [III] General formula [IV] -OCOR₄ General formula [V] -OSO₂R₅ wherein R₂, R₃ and R₅ are, independently, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted aryl, R₂ and R₃ may be the same or different; W₁ represents a group having a σp value of Hammett's rule of not less than 0.4, W₂ represents a group having a σp value of Hammett's rule of not less than 0, W₁ and W₂ may be the same or different; R₄ is substituted or unsubstituted alkyl, aryl, alkoxy, aryloxy, alkylamino or arylamino. R₁ in general formula [I] is alkyl or aryl. The alkyl group is an alkyl group having 1 to 20 carbon atoms, and such an alkyl group may have a substituent. The preferred alkyl group is of formula [VI]. General formula [VI] wherein Y represents -O-, -S-, or -SO₂-; R₆ represents alkylene with 1 to 20 carbon atoms (such as methylene, 1,1-ethylene, 1,1-propylene, 1,3-propylene, 2-methyl-1,1-propylene, 1,1-pentylene, 1,1-heptylene, 1,1-nonylene, 1,1-undecylene, 1,1-tridecylene, or 1,1-pentadecylene); R₇ is halogen (such as chlorine or fluorine); or hydroxy, or alkyl having 1 to 20 carbon atoms (such as methyl, ethyl, tert-butyl, tert-pentyl, cyclopentyl, tert-octyl, or pentadecyl); or alkoxy (such as methoxy, ethoxy, isopropoxy, butoxy, hexyloxy, or dodecyloxy); alkylsulfonamido (such as methanesulfonamido, ethanesulfonamido, butanesulfonamido, octylsulfonamido, or hexadecylsulfonamido), or arylsulfonamido (such as benzenesulfonamido, m-chlorobenzenesulfonamido, toluenesulfonamido, p-methoxybenzenesulfonamido, or p-dodecyloxybenzenesulfonamido); or alkylsulfamoyl (such as butylsulfamoyl, tert-butylsulfamoyl, or dodecylsulfamoyl); or arylsulfamoyl (such as benzenesulfamoyl, toluenesulfamoyl, or dodecyloxybenzenesulfamoyl); or alkylsulfonyl (such as methanesulfonyl or butanesulfonyl); or arylsulfonyl (such as benzenesulfonyl, p-benzyloxyphenylsulfonyl, or p-hydroxyphenylsulfonyl); or alkoxycarbonyl (such as ethoxycarbonyl, butoxycarbonyl or hexadecyloxycarbonyl); ℓ is an integer of 1 to 4, preferably, 1 or 2; when ℓ is greater than 2, R₇s may be identical or different. According to the invention, a preferred aryl group represented by R₁ in general formula [I] is phenyl, wherein the phenyl group may have a substituent which is represented by R₇ in general formula [VI]. R₂, R₃ and R₅ in general formulae [II] to [V] are, independently, hydrogen, alkyl, alkenyl, (for example, alkyl or alkenyl having 1 to 18 carbon atoms), or aryl, (for example aralkyl or aralkenyl; or aryl having 6 to 12 carbon atoms). The alkyl, alkenyl, aralkyl, aralkenyl or aryl groups represented by any of R₂, R₃ and R₅ may have a substituent, for example such as halogen such as fluorine, chlorine, or bromine, nitro, cyano, hydroxy, alkoxy, acyloxy, acylamino, sulfonamido, sulfamoyl, sulfonyl, carboxy or sulfo. Additionally, the alkyl, alkenyl, aralkyl, or aralkenyl groups represented any of R₂, R₃ and R₅ may be either straight-chained or branched. W₁ represents a group of which the σp value according to Hammett's Rule is greater than 0.4. Examples of such a group include trifluoromethyl, cyano, formyl, acyl (COR₈), alkoxycarbonyl, aryloxycarbonyl (-COOR₈), sulfonyl (-SO₂R₈), and sulfamoyl R₈, R₉ and R₁₀ are, independently, as defined for R₂, R₃ and R₅. W₂ represents a group of which σp value according to Hammett's rule is 0 or larger. Examples of such a group include halogen, (F, Cℓ, Br, and I), and carbamoyl, R₄ represents alkyl, aryl, alkoxy, aryloxy, alkylamino or arylamino. Among these groups, the alkyl and aryl portions are as previously defined for R₂, R₃ and R₅. Typical examples of the cyan coupler used in invention are listed below. Me represents CH₃. Cyan couplers used in the invention may be synthesized according to the following procedure. Synthetic scheme Synthesis example - 1 (synthesis of coupler No. 1) 5.0 g of compound [1] synthesized according to the procedure described in Japanese Patent Publication No. 45142/1974 was dissolved in 50 mℓ of methanol, into which 1.0 g of Raney nickel was added, whereby the mixture was subjected to catalytic hydrogenation under the conditions of normal temperature and pressure. Once the reaction was complete, the catalyst was removed by filtration, and then the solvent was distilled off, whereby the residue was rinsed with a solvent mixture of ethyl acetate and n-hexane. As a result, 3.7 g of compound [2] in the form of crude crystals (yield: 85%) was obtained. The compound was dissolved in 40 mℓ of ethyl acetate, into which 2.5 of N,N-dimethylaniline was added, whereby ethyl acetate solution (20 mℓ) containing 7.6 g of 2-(2,4-di-tert-amylphenoxy) hexanoylchloride was added dropwise into the solution at room temperature. The solution was subjected to stirring for five hours. 50 mℓ of ethyl acetate was added to the reaction solution, and the solution was rinsed with water and condensed under reduced pressure, whereby the residue was recrystallized using a solvent mixture of ethyl acetate and n-hexane, resulting in 7.1 g (yield: 71%) of compound [3]. The melting point, mp, of this compound was 108 to 110°C. This compound was dissolved in 100 mℓ of acetone, to which 2.1 g of potassium carbonate and 3.1 g of ethyl bromoacetate were added, and the solution was refluxed for two hours by heating. Once the reaction was complete, insoluble impurities were filtered out, and the solution was condensed under reduced pressure. Ethyl acetate was added to the residue, which was rinsed with water, and then the solvent was distilled off, thus 7.3 g (yield: 90%) of compound [4a] was obtained in the form of an oil. 20.6 g of compound [4a] was dissolved in 200 mℓ of methanol, to which a solution (20 mℓ) containing 2.7 g of sodium hydroxide was added. The solution mixture was stirred for one hour at a room temperature. Once the reaction was complete, the reaction solution was condensed under reduced pressure, and to which water was added, and acidified with hydrochloric acid, and extraction was performed using ethyl acetate. After rinsing with water, the solvent was distilled off, 100 mℓ of methanol and one or two droplets of condentrated sulfuric acid was added to the residue, which was refluxed by heating for four hours. Once the reaction was complete, the resultant solution was condensed under reduced pressure, and the residue was recrystallized with n-hexane, thus providing 15.5 g (yield: 86%) of compound [5a]. The mp of this compound was 128 to 130°C. 5.3 g of compound [5a] was dissolved in 30 mℓ of chloroform, whereby 1.1 mℓ of concentrated nitric acid (d = 1.38) was added dropwise to chloroform cooled by ice water, and then the solution was stirred for 30 minutes. Once the reaction was complete, the reaction product was rinsed with water and condensed under reduced pressure. Then, the residue was purified by means of silica gel column chromatography. As a result, 5.0 g (yield: 87%) of compound [6a] was obtained in the form of an oil. This compound was dissolved in 150 mℓ of methanol, and the solution was subjected to catalytic hydrogenation using palladium catalyst supported on carbon carrier under the conditions of a normal temperature and normal pressure. Once the reaction was complete, the catalyst was filtered out, and the remaining solution was condensed under reduced pressure, 30 mℓ of acetonitrile, 20 mg of imidazole, and 2.0 g of phenyl 3-cyano-4-chlorophenylcarbamate were added to the residue, and the mixture was heated and refluxed for two hours. The reaction solution was cooled, precipitated crystals were filtered off and recrystallized with acetonitrile. Thus, 3.4 g (yield: 53%) of coupler No. 1 was obtained. The mp of this coupler was 143 to 145°C. The structure of the coupler was identified by means of NMR, IR, and MASS techniques. Synthesis example - 2 (synthesis of coupler No. 2) 10 g of compound [3] was dissolved in 150 mℓ of acetone, to which 3.9 g of potassium carbonate and 2.6 g of chloracetone were added, whereby the solution was heated and refluxed for three hours. Once the reaction was complete, the insoluble impurites were filtered off, and then the solution was condensed under reduced pressure, and to the residue was added 100 mℓ of methanol, to which were added aqueous solution (20 mℓ) containing 1.2 g of sodium hydroxide, and the solution was stirred for one hour at a room temperature. Once the reaction was complete, the solution was condensed under reduced pressure, and to which water was added, the condensed solution was then acidified with hydrochloric acid, and then extraction was performed using ethyl acetate. After rising with water, the solvent was distilled off, and the residue was purified using silica gel column chromatography. As a result, 9.5 g (yield: 98%) of compound [5b] was obtained in the form of an oil. This compound was dissolved in 100 mℓ of chloroform, to which 2.0 mℓ of condensed nitric acid (d = 1.38) was added dropwise, and the solution was heated to 40°C and stirred for 30 minutes. Once the reaction was complete, the resultant mixture was rinsed with water and condensed under reduced pressure, and the residue was purified using silica gel column chromatography. As a result, 5.4 g (yield: 52%) of compound [6b] was obtained in the form of an oil. This compound was dissolved in 300 mℓ of methanol, and the solution was subjected to catalytic hydrogenation using a palladium catalyst supported on a carbon carrier under conditions of normal temperature and pressure. Once the reaction was complete, the catalyst was filtered off, and the remaining solution was condensed under reduced pressure, and 60 mℓ of acetonitrile, 30 mg of imidazole, and 3.2 g of phenyl 3-cyano-4-chlorophenylcarbamate were added to the residue, and the mixture was heated and refluxed for two hours. The reaction solution was cooled and precipitated crystals were filtered off. The crude crystals were then heated and rinsed with a solvent mixture of ethyl acetate and n-hexane, and recrystallized with acetonitrile, thus 4.4 g (yield: 59%) of coupler No. 2 was prepared. This coupler had an mp of 164 to 166°C. The structure of the coupler was identified by means of NMR, IR, and MASS techniques. A silver halide color photographic light-sensitive material prepared using any of the couplers according to the invention (hereinafter referred to as the couplers used in the invention) specified above may contain a conventional dye forming coupler. A cyan dye forming coupler of formula [I] may be used in compliance with conventional methods and for purposes in which known cyan dye forming coupler are conventionally used. Generally, the cyan coupler is contained within a silver halide emulsion layer and/or an adjacent non-light-sensitive layer. Typically, the cyan coupler is incorporated into a silver halide emulsion, whereby the emulsion is applied and dried onto a support, in order to prepare a silver halide color photographic light-sensitive material comprising a silver halide emulsion layer containing the cyan coupler. Such a silver halide color photographic light-sensitive material may be used for either a monochromatic or multi-color application. In a multi-color application, the cyan coupler is usually incorporated into a red-sensitive emulsion or non-sensitized emulsion. The cyan coupler may be contained in an emulsion layer that is sensitive to three primary color spectrums other than that of red. Each component for forming a dye image comprises a single emulsion layer or multi-emulsion layer which is sensitive to a specific spectral band. The layers, including the image forming component layer above, which comprise the silver halide color photographic light-sensitive material may be arranged in various orders known in the photographic art. A typical multi-color silver halide color photographic light-sensitive material comprises a support, disposed thereon a cyan dye-image forming component comprising at least one red-sensitive silver halide emulsion layer having at least one cyan dye forming coupler, in which at least one cyan coupler is the cyan coupler used in the invention; a magenta dye-image forming component comprising at least one green-sensitive silver halide emulsion layer having at least one magenta dye forming coupler; and a yellow dye-image forming component comprising at least one blue-sensitive silver halide emulsion layer having at least one yellow dye forming coupler. Such a photographic light-sensitive material may have additional layers, such as a filter layer, intermediate layer, and subbing layer. When preparing a silver halide color photographic light-sensitive material using couplers of formula [I], additional layers are necessary; a light-sensitive layer containing yellow dye forming coupler, and a light-sensitive layer containing magenta dye forming coupler. Suitable yellow dye forming couplers are those conventionally known in the art; for example, those of formula [VII]. General formula [VII] (wherein R₁₁ is alkyl or aryl; R₁₂ is aryl; Z is hydrogen, a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) The examples of Z in general formula [VII] are groups of formulae [VIII] or [IX]. General formula [VIII] (wherein F represents a group of non-metal atoms capable of forming a five- or six-membered ring.) General formula [IX] -OR₁₃ (wherein R₁₃ is aryl, and, preferably, substituted phenyl.) Suitable magenta dye forming couplers are those conventionally known in the art; for example, those of formulae [X], [XI] or [XII]. General formula [X] (wherein R₁₄ is alkylcarbonyl, aryl carbonyl, or aryl; R₁₅ is a monovalent group; Z is hydrogen, or a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) General formula [XI] (wherein R₁₆ is alkyl or aryl; R₁₇ is alkyl, aryl, or alkylthio; Z is a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) General formula [XII] (wherein R₁₈ is a monovalent group; R₁₉ is alkyl, aryl, acylamino, or alkoxy; Z is hydrogen, or a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) The cyan dye forming couplers of formula [I] may be used together with another cyan dye forming coupler. Suitable cyan dye forming couplers are those conventionally known in the art; for example, those of formulae [XIII] or [XIV]. General formula [XIII] (wherein R₂₀ is alkyl or aryl; R₂₁ is hydrogen, acylamino, alkoxycarbonylamino, sulfonamido, or ureide; Z is hydrogen, or a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) General formula [XIV] (wherein R₂₂ is alkyl or aryl; R₂₃ is alkyl; Z is hydrogen, or a group capable of splitting off in a reaction with an oxidation product of a color developing agent.) Typical examples of yellow, magenta and cyan couplers represented respectively by general formulae [VII], [X], [XI], [XII], [XIII] and [XIV] are given below. Two or more couplers of a specific dye may be used in combination. Any conventional method may be used to incorporate the cyan couplers of formula [I] as well as the other couplers into a silver halide light-sensitive material. In one such method, the cyan coupler or couplers is dissolved in a mixture of solutions containing a known high-boiling solvent, and a low-boiling solvent, such as butyl acetate and butyl propionate, and the resultant solution is blended with aqueous gelatin solution containing a surfactant. Next, the blended solution is subjected to emulsification with a high-speed mixer, colloid mill, or ultrasonic dispersion apparatus, and the dispersion is added to silver halide. Suitable high-boiling solvents are those conventionally known in the art; for example, those of formulae [XV], [XVI], [XVII], [XVIII], or [XIX]. General formula [XV] (wherein B is halogen, or alkoxy having 1 to 20 carbon atoms, or -COOR₂₄; R₂₄ is alkyl or phenyl having 1 to 20 carbon atoms; p is an integer from 0 to 3; when p is 2 or 3, B may be the same or different General formula [XVI] O = P (-OR₂₅)₃ (wherein R₂₅ is as defined earlier for R₂₄.) General formula [XVII] (wherein R₂₆ and R₂₇ are, independently, alkyl or phenyl having 1 to 20 carbon atoms; R₂₈ is hydrogen, alkyl or phenyl having 1 to 20 carbon atoms; R₂₇ and R₂₈, together with the nitrogen atom to which they are attached, may form a five- or six-membered ring together with a group of non-metal atoms.) General formula [XVIII] R₂₉COOR₂₅ (wherein R₂₉ is alkyl having 1 to 20 carbon atoms; R₂₅ is as defined above in formula [XVI] for R₂₅.) General formula [XIX] (wherein R₃₀ is alkyl group having 1 to 20 carbon; m is an integer from 1 to 3; when m is 2 or 3, R₃₀ may be identical with or different.) Typical examples of high-boiling solvents of [XV], [XVI], [XVII], [XVIII] and [XIX] follow. Two or more couplers of a specific dye may be used in combination. A silver halide color photographic light-sensitive material prepared according to the invention may, in compliance with a specific requirement, incorporate, for example, a colored coupler for color correction, a DIR (development inhibitor releasing) coupler, a non-colored coupler for improving hues of the material, or various additives conventionally used, such as an ultraviolet absorber, or an agent for stable photographic performance. Suitable colored couplers include colored magenta couplers, and colored cyan couplers which are of formulae [XX] and [XXI]. General formula [XX] M - N = N - Ar (wherein M represents a residue group formed by removing one hydrogen atom from an active site on a magenta coupler; Ar is aryl.) General formula [XXI] (wherein C represents a residue group formed by removing a hydrogen atom from an active site on a phenol class or naphthol class cyan coupler; J is a bivalent bonding group; Ar is aryl; and q is 0 or 1, respectively.) A preferred example of M in general formula [XX] is a magenta coupler represented by general formula [X] or [XI] above (R₁₄ represents a substituted phenyl group). A preferred example of C in general formula [XXI] is a cyan coupler represented by general formula [XII] above. A preferred example of q is 1. Colored magenta couplers and colored cyan couplers of formulae [XX] and [XXI] include the following compounds. More than two of the respective type of colored couplers may be used in combination. Suitable DIR couplers are of formula [XXII]. General formula [XXII] (wherein C p represents a residue group having a site which is capable of coupling to an oxidation product of a color developing agent, and one hydrogen atom removed from the site; J' represents a bivalent group which is capable of being released from C p in a reaction with an oxidation product of a color developing agent and releasing I in, for example, an intramolecular nucleophilic substitution reaction, or electron transfer, or hydrolysis; I represents a development inhibitor and q is 0 or 1.) Typical and preferred DIR couplers are listed below. More than two couplers may be used in combination, if necessary. Suitable ultraviolet absorbers are those of formulae [XXIII] and [XXIV]. General formula [XXIII] (wherein R₃₁ is akyl having 1 to 20 carbon atoms; R₃₂ is halogen; r is 1 or 2, and s is 0 or 1; when r is 2, R₃₁ may be the same or different.) General formula [XXIV] (wherein R₃₃ is aryl, or vinyl; R₃₄ and R₃₅ are, independently, cyano, alkoxycarbonyl, or arylsulfonyl.) Typical examples of suitable ultraviolet absorbers are listed below. More than two of the examples may be used in combination, if necessary. Suitable stabilizing agents include an anti-fogging agent and a dye image stabilizer, of formulae [XXV], [XXVI] and [XXVII]. General formula [XXV] (wherein R₃₆ and R₃₇ are, independently hydrogen, or alkyl having 1 to 20 carbon atoms; R₃₈ is alkyl or sulfone having 1 to 20 carbon atoms; t is 1 or 2; when t is 2, R₃₈ may be the same or different; R₃₇ and R₃₈ may together complete a five- or six-membered ring with non-metal atoms.) General formula [XXVI] (wherein R₃₆, R₃₇ and R₃₈ are as defined in formula [XXV] above; t' is 1 or 2; when t' is 2, R₃₈ may be the same or different; and, when two substituents R₃₈ are attached to adjacent carbon atoms, they may together complete a 5- or 6- membered ring.) General formula [XXVII] (wherein R₃₉ is alkyl, phenoxycarbonyl, benzenesulfonamide or alkylsulfonamide; a is 1, 2 or 3; when a is 2 or 3, R₃₉ may be the same or different.) Examples of stabilizers of formulae [XXV], [XXVI] and [XXVII] are listed below. More than two types of stabilizers may be used in combination, in compliance with a specific requirement. When incorporating the cyan coupler as well as the respective couplers according to the invention, the rate of addition is usually approximately 0.005 to 2, or, preferably, 0.01 to 0.5 mol per mol silver halide. The type of silver halide incorporated into the silver halide emulsion used in the invention is arbitrarily selected from those used in conventional silver halide emulsions, for example silver bromide, silver chloride, silver iodo-bromide, silver chloro-bromide, and silver chloro-iodo-bromide. The silver halide emulsion for composing a silver halide emulsion layer used in the invention may be prepared using a variety of methods including conventional methods. Such methods are as follows: a method, which is the method for preparing the so-called conversion emulsion, described in Japanese Patent Publication No. 7772/1971 wherein an emulsion of silver salt particles, a part of which is comprised of a silver salt having a solubility of greater than that of silver bromide, is prepared, thereby at least a portion of these silver salt particles are converted into silver bromide or silver iodo-bromide; and a method for preparing a Lippmann emulsion comprising fine particle silver halide with an average particle size of less than 0.1 µm. Additionally, the silver halide emulsion may be chemically sensitized by using certain compounds singly or in combination. Examples of such compounds are as follows: sulfur sensitizers such as arylthiocarbamide, thiourea, and cystine; active or inactive selenium sensitizers; reduction sensitizers such as stannous salt, and polyamine; noble metal sensitizers such as potassium aurithiocyanate, potassium chloroaurate, and 2-aurosulfobenzthiazole methylchloride; water soluble salt sensitizers of ruthenium, rhodium, and iridium, and, more specifically, ammonium chloropalladate, potassium chloroplatinate, and sodium chloropalladite. A silver halide emulsion used in embodying the invention may have various known photographic additives. Such additives are described, for example, in Research Disclosure Dec. 1978, No. 17643. The silver halide used in embodying the invention is spectrally sensitized using an appropriate sensitizing dye in order to provide the silver halide with sensitivity in a required spectral band. Various spectral sensitizing dyes are used for this purpose singly or in combination. Typical spectral sensitizing dyes advantageously used in the invention are cyanine dyes, merocyanine dyes, and complex cyanine dyes described in, for example, U.S. Patent Nos. 2,269,234, 2,270,378, 2,442,710, 2,454,620 and 2,776,280. The support used in the invention is selected, in compliance with a specific requirement for the photographic light-sensitive material, from those known in the art, for example, plastic film, plastic-laminated paper, baryta paper, and synthetic paper. These supports are usually subjected to subbing process in order to enhance adhesion between the support and the photographic emulsion layer. The prepared silver halide color photographic light-sensitive material is, once exposed, subjected to various photographic processes for color developing. The preferred color developer is one comprising an aromatic primary amine color developing agent as a principal component. Typical examples of color developing agents are p-phenylenediamine color developing agents, for example, diethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediamine hydrochloride, dimethyl-p-phenylenediamine hydrochloride, 2-amino-5-diethylaminotoluene hydrochloride, 2-amino-5-(N-ethyl-β-hydroxylethylamino)-toluene, 2-amino-5-(N-ethyl-β-methanesulfonamideethyl)aminotoluene sulfate, 2-amino-5-(N-ethyl-N-β-methanesulfonamideethylamino) toluene, 4-(N-ethyl-N-β-hydroxyethylamino)aniline, and 2-amino-5-(N-ethyl-β-methoxyethyl)aminotoluene. The especially preferred color developing agent is 2-amino-5-(N-ethyl-N-β-hydroxyethylamino)-toluene, or 2-amino-5-(N-ethyl-N-β-methanesulfonamideethylamino)-toluene. These color developing agents may be used singly or in combinations thereof. Additionally, these agents may be used, in compliance with a specific requirement, together with a black-and-white developing agent, such as hydroquinone. Furthermore, the color developer usually contains an alkali agent such as sodium hydroxide, ammonium hydroxide, sodium sulfite, and may further contain various additives such as an alkali metal halide, for example, potassium bromide, and a development control agent, for example citrazinic acid. The silver halide color photographic light-sensitive material of the invention may contain, in a hydrophilic colloid layer, the previously mentioned color developing agent in the form of either the color developing agent itself or a precursor thereof. A precursor of a color developing agent is a compound capable of forming a color developing agent in the presence of an alkali. Examples of such a precursor include a Schiff base type precursor of an aromatic aldehyde derivative, multi-valent metal-ion complex precursor, phthalic imido derivative precursor, phosphoric amide derivative precursor, sugar-amine reaction product precursor, and urethane precursor. These precursors of aromatic primary amine color developing agent are described in, for example, U.S. Patent Nos. 3,342,599, 2,507,114, 2,695,234 and 3,719,492, British Patent No. 803,783, Japanese Patent O.P.I. Publication Nos. 135628/1978 and 79035/1979, and Research Disclosure Nos. 15,159, 12,146 and 13,924. These aromatic primary amine color developing agents or precursors thereof should be added in an amount to ensure satisfactory coloration in color developing. The amount differs greatly depending on the type of light-sensitive material. However, the usual amount is 0.1 to 5 mol, or, preferably, 0.5 to 3 mol per mol light-sensitive silver halide. These color developing agents or the precursors thereof may be used singly or in combination. Incorporating such compounds into a photographic light-sensitive material is effected by dissolving such compounds in an arbitrary solvent such as water, methanol, ethanol, and acetone. Otherwise, such compounds may be incorporated in the form of emulsification comprising a high-boiling organic solvent such as dibutyl phthalate, dioctyl phthalate, or tricresyl phosphate; or the compounds may be incorporated after being absorbed in a latex polymer as described in Research Disclosure No. 14850. After color developing, the silver halide color photographic light-sensitive material is usually subjected to various processing steps such as bleaching and fixing, or bleach-fixing, and then washing with water. Various compounds may be used as a bleacher. Typical examples of a bleacher are multivalent metal compounds of iron (III), cobalt (III), and tin (II), in particular, complex salts of these multivalent metal cation with an organic acid. Such complex salts include metal complex salts of aminopolycarboxilic acids such as ethylenediamine tetraacetic acid, nitrilotriacetic acid, and N-hydroxyethylenediamine diacetic acid; metal complex salts of malonic acid, tartaric acid, malic acid, diglycolic acid, and dithioglycolic acid; and ferricyanates, and bichromates. EXAMPLES The following Examples illustrate the invention. Example 1 As listed in Table 1, a cyan coupler of formula [I] was weighed at a rate of 0.1 mol per 1 mol silver, and added to dibutyl phthalate, serving as a high-boiling solvent, which was present in a weight equivalent to that of the coupler, as well as to ethyl acetate which was present in a weight three times that of the cyan coupler. Each mixture was heated to 60°C to completely dissolve the coupler. Additionally, comparative samples were prepared by weighing each comparative coupler at a rate of 0.1 mol per 1 mol silver, and adding the coupler to dibutyl phthalate which was present in a weight equivalent to that of the coupler, as well as to ethyl acetate which was present in a weight three times that of the the cyan coupler. Each mixture was heated to 60°C to completely dissolve the coupler. Each of these solutions was mixed with 1200 mℓ of 5% aqueous gelatin solution comprising 120 mℓ of 5% aqueous solution of Alkanol B (alkylnaphthalene sulfonate, manufactured by DuPont). The mixture was homogenized with an ultrasonic homogenized, thus each emulsification product was prepared. Then, each dispersion was added to 4 kg of red-sensitive silver iodo-bromide emulsion (containing 7 mol% silver iodide), to which 120 mℓ of 2% aqueous solution of 1,2-bis(vinylsulfonyl) ethane (water : methanol = 1 : 1) serving as a hardener was added. The emulsion was applied onto and dried over a transparent polyester base having a subbing layer, and, thus each sample having a stable coating layer was prepared (amount of coated silver was 15 mg/100 cm²). Each sample thus prepared was subjected to wedge exposing in compliance with a conventional method, and treated in the following developing process. The results are listed in Table 1. The sensitivity and maximum color density of each sample were determined with Model PDA-65 photographic densitometer manufactured by Konica Corporation. [Processing] (38°C) Processing time Color developing 3 min. 15 sec. Bleaching 1 min. 30 sec. Washing 3 min. 15 sec. Fixing 6 min. 30 sec. Washing 3 min. 15 sec. Stabilizing 1 min. 30 sec. The compositions of the respective processing solutions are as follows. [Color developer composition] 4-amino-3-methyl-N-ethyl-N-(β-hydroxylethyl)-aniline sulfate 4.75 g Sodium sulfite anhydride 4.25 g Hydroxyamino 1/2 sulfate 2.0 g Potassium carbonate anhydride 37.0 g Sodium bromide 1.3 g Trisodium nitrilotriacetate, monohydride 2.5 g Potassium hydroxide 1.0 g Water was added to the ingredients to prepare one liter of solution, of which the pH was adjusted to 10.0 with potassium hydroxide. [Bleacher composition] Ferric ammonium ethylenediaminetetraacetate 100.0 g Diammonium ethylenediaminetetraacete 10.0 g Ammonium bromide 150.0 g Glacial acetic acid 10.0 mℓ Water was added to the ingredients to prepare one liter of solution, of which the pH was adjusted to 6.0 with aqueous ammonium solution. [Fixer composition] Ammonium thiosulfate (50% aqueous solution) 162 mℓ Sodium sulfite anhydride 12.4 g Water was added to the ingredients to prepare one liter of solution, of which the pH was adjusted to 6.5 with acetic acid. [Stabilizer] Formalin (37% aqueous solution) 5.0 mℓ Konidax (Konica Corporation) 7.0 mℓ Water was added to the ingredients to prepare one liter of solution. In the table above, the respective relative sensitivity values are based on the sensitivity of Sample No. 1 i.e. 100. The maximum absorption wavelength values (λ max ) are wavelengths giving densities of 1.0, while Δλ s indicates values obtained by subtracting, from λ max , a short-wave absorption wavelength which has 20% of the spectral absorption property obtainable from the density 1.0. Comparative coupler (A) (Compound described in Japanese Patent O.P.I. Publication No. 72245/1986) Comparative coupler (B) (Compound described in Japanese Patent O.P.I. Publication No. 72245/1986) Comparative coupler (C) (Compound described in EP-A-0 175 573) Comparative coupler (D) (Compound described in Japanese Patent O.P.I. Publication No. 72245/1986) Comparative coupler (E) (Compound described in Japanese Patent O.P.I. Publication No. 72245/1986) Table 1 shows that the comparative couplers are inferior to coupler C-2 both in terms of sensitivity and maximum color density, and that, when compared to coupler C-2 as well as the comparative couplers, each of the coupler sample Nos. 7 through 21 of formula [I] has remarkably high sensitivity as well as high maximum color density. Example 2 The respective samples prepared in Example 1 were subjected to wedge exposing, and then, to color developing as described in Example 1. Each sample was treated with bleach-fixer having the following composition, whereby the fading of cyan dye due to fatigued bleach-fixer was examined. [Bleach-fixer composition] Ferric ammonium ethylenediaminetetraacetate 50 g Ammonium sulfite (40% solution) 50 mℓ Ammonium thiosulfate (70% solution) 140 mℓ Ammonium water (28% solution) 20 mℓ Ethylenediaminetetraacetic acid 4 g Hydrosulfite 5 g Water was added to the ingredients to prepare one liter of solution. Each of the obtained samples were examined for maximum color density. Table 2 lists the results. The dye residue percent at maximum density was determined by the following expression. Table 2 shows that the sample having a naphthol coupler (C-1) indicates greatly faded cyan dye when treated with a fatigued bleach-fixer. In contrast, it is apparent from the table that the samples (Nos. 28 through 42) using a coupler of formula [I] show less faded cyan dye, as compared to the samples using comparative couplers (A) through (E). Example 3 The following layers were disposed upon a transparent polyester base having a subbing layer in the following order, in order to prepare each of the samples respectively having the constitution specified in Table 3. First layer (anti-halation layer) Aqueous gelatin solution containing black colloidal silver was applied at a rate of 0.5 g/m² in terms of amount of silver in order to form a layer with a dry thickness of 3.0 µ. Second layer (intermediate layer) Aqueous gelatin solution was applied in order to form a layer with a dry thickness of 1.0 µ. Third layer (red-sensitive low-sensitivity silver halide emulsion layer) First, a red-sensitive low-sensitivity silver halide emulsion was prepared in the following manner: an iodo-bromide emulsion (a mixture comprising, at a ratio of 2 : 1, an iodo-bromide emulsion having an average particle size of 0.6 µ with 4 mol% of silver iodide and an iodo-bromide emulsion having an average particle size of 0.3 µ with 4 mol% of silver iodide) was chemically sensitized using a gold-sensitizer and sulfur-sensitizer, to which were added, as red-sensitive sensitizing dyes, 9-ethyl-3,3'di-(3-sulfopropyl)-4,5,4',5'-dibenzothiacarbo-cyanine hydroxide anhydride, 5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfobutyl)thiacarbocyanine hydroxide anhydride, and 2-[2-{(5-chloro-3-ethyl-2(3H)-benzothiazolydene)methyl}-1-butenyl-5-chloro-3-(4-sulfobutyl)]-benzoxazolium; thereby added were 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 20.0 mg of 1-phenyl-5-mercaptotetraazole. Next, a cyan coupler, DIR compound, colored cyan coupler, anti-fogging agent and high-boiling solvent were added to 150 mℓ of ethyl acetate and dissolved with heat. The resulting solution was added to 550 mℓ of 7.5% aqueous gelatin solution containing 5 g of sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The resultant dispersion was heated to remove ethyl acetate. The red-sensitive low-sensitivity emulsion mentioned above was then added to the dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 4.0 µm (100 g gelatin contained per mol silver halide.) Fourth layer (red-sensitive high-sensitivity silver halide emulsion layer) First, a red-sensitive low-sensitivity silver halide emulsion was prepared in the following manner: an iodo-bromide emulsion (an average particle size of 1.2 µm with 7 mol% of silver) was chemically sensitized using a gold-sensitizer and sulfur-sensitizer, to which were added, as red-sensitive sensitizing dyes, 9-ethyl-3,3'-di-(3-sulfopropyl)-4,5,4',5'-dibenzothiacarbocyanine hydroxide anhydride, 3,3'-dichloro-9-ethyl-3,3'-di-(3-sulfobutyl)thiacarbocyanine hydroxide anhydride, and 2-[2-{(5-chloro-3-ethyl-2(3H)-benzothiazolydene)methyl}-1-butenyl-5-chloro-3-(4-sulfobutyl)-benzoxazolium anhydride; thereby added were 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 10.0 mg of 1-phenyl-5-mercaptotetraazole. Next, a cyan coupler, DIR compound, anti-fogging agent and high-boiling solvent were added to 60 mℓ of ethyl acetate, and dissolved with heat. The resultant solution was added to 30 mℓ of 7.5% aqueous solution containing 1.5 g of sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The red-sensitive high-sensitivity emulsion mentioned above was added to the resultant dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 2.0 µm (100 g gelatin contained per mol silver halide). Fifth layer (intermediate layer) Identical with the second layer. Sixth layer (green-sensitive low-sensitivity silver halide emulsion layer) First, a green-sensitive low-sensitivity silver halide emulsion was prepared in the following manner: an iodo-bromide emulsion having an average particle size of 0.6 µm with 4 mol% of silver iodide and an iodo-bromide emulsion having an average particle size of 0.3 µm with 7 mol% of silver iodide were independently chemically sensitized using a gold-sensitizer and sulfur-sensitizer, thereby to the respective emulsions were added, as green-sensitive sensitizing dyes, 5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfobutyl)oxacarbocyanine hydroxide anhydride, and 3,3-diphenyl-9-ethyl-3,3'-di-(3-sulfobutyl)oxacarbocyanine hydroxide anhydride, and 9-ethyl-3,3'-di-(3-sulfopropyl)-5,6,5'6'-dibenzoxycarbocyanine hydroxide anhydride. 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 20.0 mg of 1-phenyl-5-mercaptotetraazole were added; then, the two types of silver halide emulsions prepared were mixed together in a ratio of 1 : 1. Next, a magenta coupler, DIR coupler, colored magenta coupler, anti-fogging agent and high-boiling solvent were added to 240 mℓ of ethyl acetate, and then, dissolved by heating, thereby the solution was added to 7.5% aqueous gelatin solution containing sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The green-sensitive low-sensitivity emulsion mentioned above to the resultant dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 4.0 µm (100 g gelatin contained per mol silver halide). Seventh layer (green-sensitive high-sensitivity silver halide emulsion layer) First, a green-sensitive high-sensitivity silver halide emulsion was prepared in the following manner: an iodo-bromide emulsion (having an average particle size of 1.2 µm with 7 mol% of silver iodide) was chemically sensitized using a gold-sensitizer and sulfur-sensitizer, to which were added, as green-sensitive sensitizing dyes, 5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfobutyl)oxacarbocyanine hydroxide anhydride, and 5,5'-diphenyl-9-ethyl-3,3'-di-(3-sulfobutyl)oxacarbocyanine hydroxide anhydride, and 9-ethyl-3,3'-di-(3-sulfopropyl)-5,6,5'6'-benzoxacarbocyanine hydroxide anhydride; 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 10.0 mg of 1-phenyl-5-mercaptotetraazole were then added. Next, a magenta coupler, DIR coupler, colored magenta coupler, anti-fogging agent and high-boiling solvent were added to 200 mℓ of ethyl acetate and dissolved with heat. The solution was added to 7.5% aqueous gelatin solution containing sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The green-sensitive high-sensitivity emulsion mentioned above was then added to the resultant dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 2.0 µm (100 g gelatin contained per mol silver halide). Eighth layer (intermediate layer) Identical with the second layer. Ninth layer (yellow filter layer) To an aqueous gelatin solution having dispersed yellow colloidal silver were added a solution prepared by dissolving 3 g of 2,3-di-t-octylhydroquinone and 1.5 g of di-2-ethylhexyphthalate in 10 mℓ of ethyl acetate, as well as a dispersion prepared by dissolving 0.3 g of sodium triisopropylnaphthalenesulfonate. The resultant emulsion was applied so that a dry thickness was 1.2 µm containing gelatin at a rate of 0.9 g/m², and 2,5-di-t-octylhydroquinone at a rate of 0.10 g/m². Tenth layer (Blue-sensitive low-sensitivity silver halide emulsion layer) An iodo-bromide emulsion having an average particle size of 0.6 µm with 6 mol% of silver iodide was chemically sensitized using a gold-sensitizer and sulfur-sensitizer, thereby to the emulsions was added, as sensitizing dyes, 5,5'-dimethoxy 3,3'-di-(3-sulfopropyl)thiacyanine hydroxide anhydride, and then 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 20.0 mg of 1-phenyl-5-mercaptotetrazole. Then the mixture was treated with a conventional technique, and a blue-sensitive low-sensitivity silver halide emulsion was prepared. Next, a yellow coupler, and high-boiling solvent were added to 300 mℓ of ethyl acetate and dissolved with heat, thereby the solution was added to 7.5% aqueous gelatin solution containing sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The blue-sensitive low-sensitivity emulsion mentioned above was added to the resultant dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 4.0 µm (240 g gelatin contained per mol silver halide). Eleventh layer (blue-sensitive high-sensitivity silver halide emulsion layer) An iodo-bromide emulsion (an average particle size of 1.2 µ with 7 mol% of silver iodide was chemically sensitized using a gold-sensitizer and sulfur-sensitizer, thereby to the emulsion were added, as sensitizing dyes, 5,5'-dimethoxy-3,3'-di-(3-sulfopropyl)thiacyanine hydroxide anhydride, and then 1.0 g of 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 10.0 mg of 1-phenyl-5-mercaptotetraazole. Then the mixture was treated with a conventional technique, and a blue-sensitive high-sensitivity silver halide emulsion was prepared. Next, a yellow coupler, and high-boiling solvent were added to 240 mℓ of ethyl acetate and dissolved with heat, thereby the solution was added to 7.5% aqueous gelatin solution containing sodium triisopropylnaphthalenesulfonate, and the mixture was homogenized using a colloid mill. The blue-sensitive high-sensitivity emulsion mentioned above was added to the resultant dispersion. The resultant emulsion was applied in order to form a layer with a dry thickness of 2.0 µm (160 g gelatin contained per mol silver halide). Twelfth layer (intermediate layer) To 2 mℓ of ethyl acetate were added a high-boiling solvent and ultraviolet absorbent, thereby the solution was added to 7.5% aqueous gelatin solution containing sodium triisopropylnaphthalene sulfonate, and the mixture was homogenized with a colloid mill. The resultant emulsion was applied in order to form a layer with a dry thickness of 1.0 µm and rate of gelatin applied was 1.0 g/m². Thirteenth layer (protective layer) An aqueous gelatin solution containing 4 g gelatin per 100 mℓ and 0.2 g of 1,2-bisvinylsulfonylethane per 100 mℓ was applied so that amount of gelatin applied was at a rate of 1.3 g/m² and a dry thickness was 1.2 µm. In Table 3, the amounts applied indicate amounts per mol silver halide, whereby the amounts of coupler, DIR coupler and colored coupler are given in mol%, the amounts of high-boiling solvent and ultraviolet absorbent are given in weights per m². The amount (g per m²) of high-boiling solvent was equal to that of ultraviolet absorbent. Additionally, the amount (g per m²) of anti-fogging agent in the fifth layer is given in weight (g) per m²; and the amount by weight of high-boiling solvent used was the same as that of the anti-fogging agent. Each sample prepared with a constitution specified in Table 3 was treated with the processing steps described in Example 1. As a result, each sample was found to be a silver halide color photographic light-sensitive material having satisfactory color balance. In contrast to conventional techniques, by using a cyan coupler represented by general formula [I], the present invention provides a cyan dye image with high sensitivity and high color density free from dye loss even when treated with a fatigued bleaching bath or bleach-fixing bath. This photographic light-sensitive material also excels in spectral property and is capable of providing a cyan coupler with excellent dispersion stability.

Claims: A silver halide color photographic light-sensitive material comprising a silver halide emulsion layer containing a cyan coupler of formula [I]: wherein R₁ is substituted or unsubstituted alkyl group or substituted or unsubstituted aryl group, and Z is a group of formula [II], [III], [IV] or [V]: wherein R₂, R₃ and R₅ are, independently, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted aryl; W₁ represents a group having a σ p value of Hammett's rule of not less than 0.4, W₂ represents a group having a σ p value of Hammett's rule of not less than 0; R₄ is substituted or unsubstituted alkyl, aryl, alkoxy, aryloxy, alkylamino or aryl amino. A silver halide color photographic light-sensitive material according to claim 1, wherein said alkyl group represented by R₁ is a group having one to twenty carbon atoms, which may be substituted or unsubstituted. A silver halide color photographic light-sensitive material according to claim 2, wherein said alkyl group is of formula [VI]: wherein Y is oxygen, sulfur or -SO₂-; R₆ is substituted or unsubstituted alkylene having one to twenty carbon atoms and R₇ is halogen, hydroxyl, or substituted or unsubstituted alkyl having one to twenty carbon atoms, alkoxy, alkylsulfonamido, arylsulfon-amido, alkylsulfamoyl, arylsulfamoyl, alkylsulfonyl, arylsulfonyl or alkoxycarbonyl; ℓ is an integer of from 1 to 4, provided that, when ℓ is 2 or more, R₇s may be the same or different. A silver halide color photographic light-sensitive material according to claim 1, wherein said aryl group represented by R₁ is a substituted or unsubstituted phenyl group. A silver halide color photographic light-sensitive material according to any one of the preceding claims, wherein said group represented by W₁ is trifluoromethyl, cyano, formyl, or substituted or unsubstituted acyl, alkoxycarbonyl, aryloxycarbonyl, sulfonyl or sulfamoyl group. A silver halide color photographic light-sensitive material according to any one of the preceding claims, wherein said group represented by W₂ is halogen, trifluoromethyl, cyano, formyl or substituted or unsubstituted carbamoyl, acyl, alkoxycarbonyl, aryloxycarbonyl, sulfonyl or sulfamoyl group. A silver halide color photographic light-sensitive material according to any one of the preceding claims, wherein said cyan coupler is contained in said silver halide emulsion layer in an amount of from 0.005 mol to 2 mol per mol of silver halide contained in said silver halide emulsion layer. A silver halide color photographic light-sensitive material according to claim 7, wherein said cyan coupler is contained in said silver halide emulsion layer in an amount of from 0.01 mol to 0.5 mol per mol of silver halide contained in said silver halide emulsion layer.

Inventors: KIDA, SHUJI, KIMURA, TOSHIHIKO, MIURA, NORIO, NAKAGAWA, SATOSHI
Applicants: KONICA CORPORATION
Application year: 1988
Main classification: G03C7
IPC codes: G03C7