RAPIDLY PROCESSABLE SILVER HALIDE COLOR PHOTOSENSITIVE MATERIAL

Abstract: A silver halide color photographic light sensitive material comprising a support having thereon at least one photographic component layer including at least one silver halide emulsion layer comprising: (a) silver halide grains comprising not less than 80 mol% of silver chloride, (b) a gold compound in an amount of from 5 × 10⁻⁷ to 5 × 10⁻³ mol per mol of silver halide contained in the silver halide emulsion layer, (c) a sulfur sensitizer, and (d) a spectral sensitizing dye of formula [I] in an amount of from 5 × 10⁻⁶ to 3 × 10⁻³ mol per mol of silver halide contained in the silver halide emulsion layer: wherein X₁, X₂, X₃, and X₄ are, independently, hydrogen, a halogen, alkyl, alkoxy, aryl or hydroxy; R₁ and R₂ are, independently, alkyl; X⁻ is an anion and n is 0 or 1.

Description: The present invention relates to a process for the preparation of a silver halide color photosensitive material and, more particularly, to a process for the preparation of a rapidly processable silver halide color photosensitive material having a silver halide emulsion layer composed principally of silver chloride and which is able to produce a satisfactory dye image when rapidly processed. Normally, according to a dye image producing method in which a silver halide color photosensitive material is used, after an image-like exposure is effected, an oxidized p-phenylenediamine type color developing agent is reacted with a dye forming coupler, whereby a dye image is produced. In such method, a color reproduction technique based on a subtractive color process is usually applied so that dye images in cyan, magenta, and yellow are formed on corresponding photosensitive layers in complementary relation to the three colors red, green, and blue respectively. Recently, in order to shorten the development time required in connection with the formation of such dye images, it has become usual practice to employ high-temperature development techniques and reduce the number of processing steps required. In order that the development time may be shortened through high temperature development in particular, it is very important to increase the rate of development in the process of color developing. The rate of development in the process of color development is subject to the effects of two sources. One of the sources is the silver halide color photosensitive material used and the other is the color developing solution used. With the former it has been found that the particle shape and size in and the composition of the photosensitive silver halide emulsion used, in particular, have considerable bearing on the rate of development, while with the latter it has been found that the rate of development is likely to be influenced by the conditions of the color developing solution and, more particularly, by the type of development restrainer used, and that grains which contain a high concentration of silver chloride in particular exhibit a remarkably high development rate under specific conditions, for example, such that bromide ions conventionally used for color development are not contained in the color developing solution. In a photosensitive material for use as a color paper, a blue-sensitive emulsion layer is normally present as the lowermost layer, and therefore the emulsion layer is required to contain silver halide grains which show high sensitivity and a high rate of development. A method for increasing the rate of development is known in which a combination of a silver halide and a low-bromide silver is used, as disclosed in JP-A-58-184142 and JP-B-56-18939. However, the difficulty with methods in which the silver chloride content of the emulsion layer is increased is that the photosensitivity is inevitably lowered. This is attributable to the fact that pure silver chloride absorbs almost no visible light by nature. Attempts directed toward overcoming this difficulty have been made using a combination of such spectral sensitizing dyes as mentioned in JP-A-58-91444, 58-95339, and EP-A-0 082 649, or of such spectral sensitizing dyes having different wave lengths as mentioned in JP-A-58-95340 and EP-A-0 082 649. However, no mention is made in these publications as to changes in gradation due to the use of a high silver chloride in combination with such dyes. As such, these combinations have not been successful for use in a color photosensitive material, or more particularly for use in a color paper. It has also been found that the use of a spectral sensitizing dye in the form of a cyanine dye having two benzothiazole rings in a molecule can enhance spectral sensitization in the visible light range, and more particularly in the light range of 430 nm - 480 nm, thereby providing sufficient sensitivity even where a high-purity silver chloride is used. In this case, however, the difficulty is that if the high-purity silver chloride is used in combination with such spectral sensitizing dye, a downward change in gradation will take place where development is effected with a color developing solution using a p-phenylenediamine of the type which is normally used for the purpose of development, so that it is not possible to obtain satisfactory color reproduction. Another difficulty is that where a developing solution having little or no bromide content is used with a view to increasing the rate of development, far much greater deterioration in gradation will result. Recently, in order to minimize possible pollution loads arising from the processing of silver-halide photosensitive materials, there has been a strong demand for elimination of benzyl alcohol, a coupling improves, from color developing solutions. If this demand is considered in conjunction with aforesaid color developing solutions having no bromide ion content, that is, if a color developing solution containing neither bromide nor benzyl alcohol is used, it has been found that a photosensitive material using such spectral sensitizing dye and such high-purity silver chloride grains will not only show an excessively decreasing gradation, but also will excessively enhance reduction in maximum photodensity. US Patent No. 4 225 666 discloses a method of preparing a spectrally sensitized radiation-sensitive silver chloride emulsion comprising the addition of a methine spectral sensitizing dye to an aqueous solution of a silver salt, an aqueous solution of a halide salt and a peptizer. In this process, the sensitizing dye is incorporated in the silver halide emulsion before the end of the first ripening stage which corresponds to the precipitation of the silver halide. This invention is intended to overcome the aforesaid difficulties, and seeks to provide a process for the preparation of a silver halide color photosensitive material with a high silver chloride content and yet is able to prevent the development of any excessive decrease in gradation with a dye image produced from the material, and which, even when a color developing solution having no benzyl alcohol content is used, can assure a sufficient maximum density and formation of a satisfactory dye image at a very high rate of development. Accordingly, the invention provides a process for the preparation of a silver halide color photographic light sensitive material comprising a support having thereon at least one photographic component layer including at least one silver halide emulsion layer comprising: (a) silver halide grains comprising not less than 80 mol% of silver chloride, (b) a gold compound in an amount of from 5 x 10⁻⁷ to 5 x 10⁻³ mol per mol of silver halide contained in the silver halide emulsion layer, (c) a sulfur sensitizer and (d) a spectral sensitizing dye of formula [I] in an amount of from 5 x 10⁻⁶ to 5 x 10⁻² mol per mol of silver halide contained in the silver halide emulsion layer: wherein X₁, X₂, X₃ and X₄ are, independently, hydrogen, halogen, alkyl, alkoxy, aryl or hydroxy; R₁ and R₂ are, independently, optionally substituted alkyl; X ⊖ is an anion and n is 0 or 1, which process comprises incorporating the sensitizing dye in the emulsion after the end of a first ripening stage and before the end of a second ripening stage. The above-mentioned silver halide grains containing not less than 80 mol% of silver chloride, the gold compound, sulfur sensitizer, and the compound expressed by formula [I] are all contained in one silver-halide emulsion layer (which is hereinafter sometimes referred to as the "silver halide emulsion layer used in the invention"), if the photosensitive material in accordance with the invention has only one such emulsion layer. If the photosensitive material has a plurality of silver-halide emulsion layers, at least one of the layers should be the silver halide emulsion layer used in the invention. Preferably, a blue sensitive emulsion layer which is usually formed as the lowermost layer (i.e., the layer nearest to the base) has the aforesaid compositional features of the invention so that it constitutes the silver halide emulsion layer used in the invention. More preferably, a yellow coupler contained in the blue sensitive emulsion layer is selected from the couplers represented by the general formula [Y] mentioned hereinafter. If the photosensitive material has a plurality of silver halide emulsion layers some of those layers need not be of the same composition as the silver halide emulsion layer used in the invention. Specific compositional features of the invention will now be described. Gold compounds useful for incorporation in the silver halide emulsion layer include, for example, aurate chloride, sodium chloroaurate, and potassium thiosulfo-aurate (but without limitation thereto). The proportion of such gold compound used is 5 x 10⁻⁷ to 5 x 10⁻³ mol per mol of the silver halide, preferably 1.0 x 10⁻⁶ to 1 x 10⁻⁴ mol. More preferably, it is 1.0 x 10⁻⁶ to 4 x 10⁻⁵, most preferably 1.0 x 10⁻⁶ to 9 x 10⁻⁶. The gold compound may be added at any stage in the process of silver halide emulsion preparation, but preferably between the end of the stage of silver halide formation and the end of the stage of chemical sensitization. Alternatively, it may be added after the end of the stage of chemical ripening, or more particularly after the addition of a compound known as an antifoggant or stabilizer and before the stage of silver halide emulsion coating. In other words, the gold compound is effective even when added at any time other than at a usual time for gold sensitization, that is, at any time at which it cannot exhibit its sensitizing effect. Sulfur sensitizers useful for incorporation in the silver halide emulsion layer used in the invention include, for example, sodium thiosulfate, and thiourea derivatives such as diphenyl thiourea and allyl thiourea. A sulfur sensitizer may be added in such quantity as is sufficient to sensitize the silver halide. There is no particular limitation on the quantity of sulfur sentizer, but where sodium thiosulfate is used, it is added preferably at the rate of from 1 x 10⁻⁷ to 1 x 10⁻⁵ mol per mol silver halide, more preferably at the rate of from 2 x 10⁻⁶ to 8 x 10⁻⁶ mol per mol silver halide. Compounds expressed by formula [I] are discussed below: In the spectral sensitizing dye of formula [I], X₁, X₂, X₃, and X₄ represent hydrogen, halogen, alkyl, alkoxy, aryl, or hydroxy. More specifically, a halogen may be, for example, chlorine. Alkyl groups may be, for example, methyl or ethyl having from 1 to 6 carbon atoms. Alkoxy groups may be methoxy or ethoxy having from 1 to 6 carbon atoms. Preferably, at least one of X₁, X₂, X₃ and X₄ is chlorine, and more preferably two of X₁, X₂, X₃ and X₄ are chlorine. R₁ and R₂ represent optionally substituted alkyl. Preferably, R₁ and R₂ are unsubstituted alkyl, or carboxyl- or sulfo-substituted alkyl, more preferably carboxyl- or sulfo-substituted alkyl. Most preferably, they are sulfo-alkyl or carboxy-alkyl having from 1 to 4 carbon atoms. R₁ and R₂ may be identical with or different from each other. Preferably, one of them is a carboxyl-substituted alkyl group having 1 to 4 carbon atoms. X ⊖ represents an anion. Though not definitive, it may be a halogen ion (such as Br⁻ or I⁻). n represents 0 or 1. Spectral sensitizing dyes of formula [I] are individually known compounds, which may easily be synthesized by reference to various publications, such as for example the respective specifications of British Patent No. 660408, U.S. Patent No. 3149105, and JP-A-50-4127, as well as F.M. Hamer, "The Cyanine Dyes and Related Compounds", Interscience Publishers, New York, 1969, pp 32 - 76. Examples of spectral sensitizing dyes of formula [I] which may be used in the present invention are shown in Table 1 below. In Table 1 above, NEt₃ represents In the present invention, the proportion of any such spectral sensitizing dye as exemplified above, relative to silver halide, is 5 x 10⁻⁶ - 5 x 10⁻² mol/AgX mol. Preferably, the proportion is 1 x 10⁻⁵ - 1 x 10⁻³ mol/AgX mol. Most preferably, it is 1 x 10⁻⁴ - 9 x 10⁻⁴ mol/AgX mol. In carrying out the present invention, the spectral sensitizing dye may be added to an emulsion of silver halide according to any relevant technique well known in the art. For example, the sensitizing dye may be dispersed directly in the emulsion, or may be added to the emulsion in the form of an aqueous solution or a solution prepared by dissolving the dye in a water soluble solvent, such as pyridine, methyl alcohol, ethyl alcohol, methyl Cellosolve, or acetone (or a mixture of any such solvents), or in the form of a solution of the dye diluted with water. Ultrasonic vibration may be advantageously used in connection with the dissolving step. For the purpose of such an addition it is possible to use the method disclosed in U.S. Patent No. 3,469,987, in which a sensitizing dye is dissolved in a volatile organic solvent and the resulting solution is dispersed in a hydrophilic colloid, the dispersion being added to the emulsion; or a method disclosed in, for example, JP-B-46-24185, in which a water insoluble dye is dispersed in a water soluble solvent without being dissolved, the dispersion being then added to the emulsion. Any such spectral sensitizing dye may be added to the emulsion in the form of a dispersion by the acid dissolution-dispersion technique. Methods disclosed in U.S. Patent Nos. 2,912,345, 3,342,605, 2,996,287, and 3,425,835 may also be employed in adding the dye to the emulsion. A single spectral sensitizing dye expressed by formula [I] may be used alone for the purpose of the invention, or two or more of such dyes may be used in combination. Where two or more of such dyes are used, they may be added either simultaneously or separately. If they are added separately, the sequence, timing, and intervals for the addition may be determined according to the intended object. If so desired, such dye may be used in combination with a sensitizing dye other than those of formula [I]. The sensitizing dye may be added to the silver halide photosensitive emulsion in parts. The silver halide emulsion used in the formation of the silver halide emulsion layer used in the invention may be of silver chlorobromide, silver iodochloride, or silver chloroiodobromide silver chloride, provided that it is a silver halide emulsion containing not less than 80 mol% of silver chloride. Preferably, the emulsion contains silver chloride in an amount of from 95 to 100 mol%, and more preferably, of from 99.0 to 99.9 mol%. The emulsion may contain silver iodide but the content of silver iodide is preferably not more than 1 mol%, more preferably not more than 0.5 mol%. Most preferably, the emulsion contains no silver iodide. The silver bromide content of the emulsion is preferably less than 5 mol%, or it may be even 0 mol%. In the present invention, the silver halide grains containing not less than 80 mol% of silver chloride should preferably constitute not less than 80% by weight, more preferably 100% by weight, of the entire silver halide grain content of the silver halide emulsion layer in which the silver halide grains are contained. Further, the mean silver chloride content of the emulsion layer in which the silver halide grains are contained should preferably be not less than 80 mol%, more preferably not less than 85 mol%. The silver halide grains contained in the silver halide emulsion layer should preferably have a mean silver halide content of not less than 80 mol%, which means that the molar ratio of silver chloride to the entire emulsion layer is not less than 80 mol%. It is permissible to have a partial deviation from said compositional feature of the grains, or the layer to contain some other substance (such as for example pure silver bromide) than the one represented by said molar ratio. When the photosensitive material prepared by a process according to the invention has a plurality of silver halide emulsion layers, some of the emulsion layers may be of a different composition from that of the silver halide emulsion layer used in the invention, and these other emulsion layers need not be of a high silver chlorohalide composition. However, the emulsion layers, as a whole, of the photosensitive material preferably have a mean silver halide content of not less than 80 mol%, and more preferably all the emulsion layers contain silver halide grains having a silver chloride content of not less than 80 mol%. It is particularly desirable that all the layers have, on average, a silver chloride content of not less than 95 mol%. Silver halide grains used in the color photosensitive material prepared in accordance with the invention, namely, silver halide grains used in the silver halide emulsion layer and other emulsion layer or layers which may be formed as required (hereinafter referred to as "silver halide grains used in the invention") preferably have a mean grain size of less than 5 µm, more preferably less than 3 µm, and most preferably less than 1 µm, in terms of mean grain diameter as defined by the following equation: in which r represents mean grain diameter; r i represents individual grain diameter; and n i represents the number of particles having individual grain diameter r i . It is noted that if the silver halide grains are of a cubic shape, the length of one side of the cube is taken as the diameter of each individual grain; and if the grains are spherical or of any shape other than cubic, the length of one side of a cube having same volume is taken as the diameter of each individual grain. The grain diameter distribution of the silver halide grains used in the invention may be of a polydisperse pattern or of a monodisperse pattern, but it is desirable that the silver halide emulsion should be monodisperse. In this connection it is noted that the term monodisperse herein means that the coefficient of variation of the grain diameter distribution of silver halide grains contained in the emulsion is not more than 22%, preferably not more than 15%. The coefficient of variation indicates the spread of grain diameter distribution and is defined by the following equation: The grain diameter can be measured by various methods conventionally used in the art for the above mentioned purpose. A typical method is described in Lapland "Method of Grain Diameter Analysis", A.S.T.M. Symposium on Light Microscopy, 1955, pp 94 - 122. Another typical method is described in "The Theory of Photographic Process", Mees and James, 3rd ed., The Macmillan Press Ltd (1966), Chap. 2. The term "silver halide emulsion" refers to an emulsion constituting the silver halide emulsion layer used in the invention and any emulsion constituting any other emulsion layer which may be formed as required. Silver halide grains used for this purpose may be produced by the acid process, the neutral process, or the ammonia process, for example. The grains may be grown all at once, or seed grains may be prepared initially which are then grown. The technique for seed grain preparation may be the same as or different from the technique for grain growing. The silver halide emulsion may be prepared by mixing together an halide ion and a silver ion, or by mixing one into a liquid in which the other is present. Alternatively, the halide ion and the silver ion may be gradually added together in a mixing vessel while the pH and pAg in the vessel are properly controlled paying attention to the critical rate of growth of silver halide crystals so that they are grown into a silver halide emulsion. Thus, it is possible to obtain monodispersed silver halide grains having good regularity in crystal form and good uniformity in grain diameter. After their growth, the grains may be varied in their halogen composition by using a conversion technique. Any appropriate apparatus can be used to prepare the silver halide emulsion. More particularly, apparatuses utilizing any one of the following methods can be advantageously employed. In one such method an aqueous silver halide solution and an aqueous solution of salt halide are introduced through nozzles immersed in a hydrophilic colloidal solution in a mixture pot. In another method the concentration of an addition liquid is successively varied. In another method excess quantities of soluble salt and water in a hydrophilic colloidal solution in the mixing vessel are removed, for example, by ultrafiltration in order to prevent interparticle intervals from becoming larger. In the process of manufacturing the silver halide emulsion used in the invention, the size and shape of silver halide grains, their grain size distribution, and the rate or their growth can be suitably controlled by using a silver halide solvent as required. A metallic ion selected from a cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt (present as a complex salt), a rhodium salt (present as a complex salt), or a ferric salt (present as a complex salt) may be added to the silver halide grains during grain formation and/or grain growth. The resulting grains contain the metallic element in their interior and/or on their surface, or may have a reduction sensitivity speck in their interior and/or on their surface when placed in a reductive atmosphere. The silver halide emulsion used in the invention may be cleared of all unnecessary soluble salts at the end of the stage of silver halide grain growth, or may be allowed to contain such salts as they are. For the purpose of removing such salts, the method described in "Research Disclosure" No. 17643 may be employed. Silver halide grains used in the silver halide emulsion may be either those having a uniform silver halide distribution within their interior or core/shell grains having silver halide compositions that differ between their interior and their surface. Silver halide grains in a silver halide emulsion having a high chloride content are likely to have a cubic shape. However, by allowing the presence of various different compounds during the stage of grain formation, it is possible to prepare a regular crystal shape as, for example, a cube, octahedron, or a quaterdecahedron. In another permissible crystal form, they may have an irregular configuration, for example, spherical or lamellar. These grains may have any desired side-to-side ratio. Also, they may have a composite form of these crystalline shapes, or they may be a mixture of grains having different crystalline shapes. In the present invention, however, cubic grains are preferably used. The silver halide emulsion used in the invention may be a mixture of two or more kinds of silver halide emulsions which have been prepared separately. The silver halide color photographic light sensitive material of the invention may preferably contain a black-and-white developing agent in one of the photographic structural layers. The scope of black-and-white developing agents which may be used in the invention is not specifically limited and includes those widely used in the photographic art. Specifically, however, the preferred agents include triazole-3-pyrazolidone compounds, di- or poly-hydroxybenzene compounds and N-alkyl-p-aminophenol compounds. Typical examples of black-and-white developing agents usable in connection with the present invention are as follows. D-1 1-Phenyl-3-pyrazolidone D-2 1-Tolyl-3-pyrazolidone D-3 4-Methyl-1-phenyl-3-pyrazolidone D-4 4-Methyl-4-hydroxylmethyl-1-phenyl-3-pyrazolidone D-5 4,4-Dimethyl-1-phenyl-3-pyrazolidone D-6 4-Methyl-4-hydroxylethyl-1-phenyl-3-pyrazolidone D-7 4-Methyl-4-acetoxymethyl-1-phenyl-3-pyrazolidone D-8 4-Methyl-4-butanoyloxymethy-1-phenyl-3-pyrazolidone D-9 4-Methyl-4-hydroxymethyl-1-tolyl-3-pyrazolidone D-10 4-Methyl-4-hydroxymethyl-1-phenyl-5-phenyl-3-pyrazolidone D-11 1,4-Dihydroxybenzene D-12 1,2-Dihydroxybenzene D-13 2-Chloro-1,4-dihydroxybenzene D-14 2-Methyl-1,4-dihydroxybenzene D-15 2,5-Dimethyl-1,4-dihydroxybenzene D-16 Sodium 1,4-Dihydroxybenzene-5-sulfonate D-17 Sodium 1,4-Dihydroxybenzene-5-carboxylate D-18 Sodium 1,5-Dihydroxybenzene-2,5-dicarboxylate D-19 Sodium 1,2-Dihydroxybenzene-4-sulfonate D-20 Sodium 1,2-Dihydroxybenzene-4-carboxylate D-21 Sodium 1,2-Dihydroxybenzene-3,5-disulfonate D-22 Sodium 1,2-Dihydroxybenzene-3,5-dicarboxylate D-23 N-Methyl-P-aminophenol D-24 N-Ethyl-P-aminophenol To incorporate the black-and-white developing agent into the photographic structural layers the agent may be added either unchanged or after being dissolved in an appropriate solvent such as water or alcohol (which does not exert adverse effects on the light-sensitive material) at an appropriate proportion to the coating solutions to form the layers. The black-and-white developing agent may be incorporated into the layers after being dissolved in high boiling and/or low boiling organic solvents and then dispersing and emulsifying the solvents into water. Examples of high boiling solvents, i.e. those having boiling points higher than 150°C, are as follows: phenol derivatives, alkyl phthalates, phosphates, citrates, benzoates, alkylamides, fatty acyl esters, and trimesyl esters, each of which does not react with the oxidized product of the developing agent. Organic solvents having high boiling points are disclosed in the following patents: U.S. Patents No. 2,332,027, No. 2,533,514, No. 2,835,579, No. 3,387,134, No. 2,353,262, No. 2,852,383, No. 3,554,755, No. 3,676,137, No. 3,676,142, No. 3,700,454, No. 3,748,141, No. 3,779,765 and No. 3,837,863; British patents No. 958,441 and No. 1,333,753; West German OLS Patent No. 2,538,889; Japanese Patent O.P.I. Publications No. 1031/1972, No. 90523/1974, No. 23823/1975, No. 26037/1976, No. 27921/1976, No. 27922/1976, No. 26035/1976, No. 26036/1976, No. 62632/1975, No. 1520/1978, No. 1521/1978, No. 15127/1978, No. 119921/1979, No. 119922/1979, No. 25057/1980, No. 36869/1980, No. 19049/1981 and No. 81836/1981, and Japanese patent Examined Publications No. 29060/1973. Low boiling or water soluble organic solvents which may be used together with or instead of the high boiling solvents are described in, for example, U.S. Patents No. 2,801,171 and No. 2,949,360. Examples of low boiling organic solvent are as follows: i) substantially water insoluble: ethyl acetate, propyl acetate, butyl acetate, butanol, chloroform, carbon tetrachloride, nitromethane, nitroethane and benzene; ii) water soluble: acetone, methyl isobutylketone, β-ethoxyethyl acetate, methoxy glycol acetate, methanol, ethanol, acetonitrile, dioxane, dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide, diethylene glycol-monophenyl ether and phenoxylethanol. The black-and-white developing agent may be added at any step during the manufacturing process, but it is generally favorable to add the agent to the emulsion immediately before it is applied. The black-and-white developing agent may be a combination of more than two agents. The black-and-white developing agent may be contained in any of the photographic component layers; however, it is advantageous to incorporate the agent into the silver halide emulsion layers or adjacent layers thereto. The amount of developing agent added depends on the type of agent and the silver halide, but ordinarily, 0.1 - 100 mg, or favorably 0.5 - 10 mg, per m² is added. The sensitizing dye represented by formula [I] and the black-and-white developing agent may be contained in a same layer or in different layers. The light sensitive material of the invention may contain a dye-forming coupler capable of forming a dye by coupling with the oxidized product of an aromatic primary amine developing agent (such as, for example, p-phenylenediamine derivative and aminophenol derivative) during color developing. Such couplers may be contained in any of the emulsion layers of the light sensitive material. However, as mentioned previously, the yellow coupler should favorably be contained within the silver halide emulsion layer. Yellow couplers suitable for use in the process of the invention are described in, for example, the following patents : U.S. Patents No. 2,186,849, No. 2,322,027, No. 2,728,658, No. 2,875,057, No. 3,265,506, No. 3,277,155, No. 3,408,194, No. 3,415,652, No. 3,447,928, No. 3,664,841, No. 3,770,446, No. 3,778,277, No. 3,849,140 and No. 3,894,875; British Patents No. 778,089, No. 808,276, No. 875,476, No. 1,402,511, No. 1,421,126 and No. 1,513,832; Japanese Patent Examined Publication No. 13576/1974; Japanese Patent O.P.I. Publications No. 29432/1973, No. 66834/1973, No. 10736/1974, No. 122335/1974, No. 28834/1975, No. 132926/1975, No. 1338832/1975, No. 3631/1976, No. 17438/1976, No. 26038/1976, No. 26039/1976, No. 50734/1976, No. 53825/1976, No. 75521/1976, No. 89728/1976, No. 102636/1976, No. 107137/1976, No. 117031/1976, No. 122439/1976, No. 1443319/1976, No. 9529/1978, No. 82332/1978, No. 135625/1978, No. 145619/1978, No. 23528/1979, No. 48541/1979, NO. 65035/1979, No. 133329/1979 and No. 598/1980. Examples of particularly favorable yellow couplers include those of formula [Y] below. More specifically, yellow couplers which are advantageously used in the color photographic light sensitive material are divalent, non-diffusible yellow couplers of formula [Y]: wherein R₂₁ is halogen or alkoxy; R₂₂ is -NHCOR₂₃SO₂R₂₄, -COOR₂₄, -COOR₂₃COOR₂₄, or in which R₂₃ is alkylene, R₂₄ is a ballast group and R₂₅ is alkyl, aralkyl or hydrogen; and Z₂₁ is a group capable of being split off in a reaction with an oxidized product of a color developing agent. Typical examples of divalent yellow couplers advantageously used in the invention are listed below. [Example coumpounds] The yellow couplers above are typically used at a rate of 0.02 - 1 mol, favorably, 0.05 - 0.75 mol, more favorably, 0.05 - 0.75 mol, and most favorably 0.1 - 0.5 mol per mol silver halide. The yellow couplers above may be used as a mixture comprising, at an arbitrarily selected ratio, more than two similar couplers. Magenta couplers suitable for use include, for example, those mentioned in the respective specifications of U.S. Patent Nos. 1,969,479, 2,213,986, 2,294,909, 3,338,677, 2,340,763, 2,343,703, 2,359,332, 2,411,951, 2,435,550, 2,592,303, 2,600,788, 2,618,641, 2,619,419, 2,673,801, 2,691,659, 2,803,554, 2,829,975, 2,866,706, 2,881,167, 2,895,826, 3,026,653, 3,127,269, 3,214,437, 3,253,924, 3,311,476, 3,419,391, 3,486,894, 3,519,429, 3,558,318, 3,617,291, 3,684,514, 3,705,896, 3,725,067, and 3,888,680, British Patent Nos. 720,284, 737,700, 813,866, 892,886, 918,128, 1,019,117, 1,042,832, 1,047,612, 1,398,828, and 1,398,979, German patent Publications Nos. 814,996, and 1,070,030, Belgian Patent Publication No. 724,427, and Japanese Pulished Unexamined Patent Application Nos. 46-60479, 49-29639, 49-111631, 49-129538, 50-13041, 50-116471, 50-159336, 51-3232, 51-3233, 51-10935, 51-16924, 51-20826, 51-26541, 51-30228, 51-36938, 51-37230, 51-37646, 51-39039, 51-44927, 51-104344, 51-105820, 51-108842, 51-112341, 51-112342, 51-112343, 51-112344, 51-117032, 51-126831, 52-31738, 53-9122, 53-35122, 53-75930, 53-86214, 53-25835, 53-123129, and 54-56429. Cyan couplers suitable for use include, for example, those mentioned in the respective specifications of U.S. Patent Nos. 2,306,410, 2,356,475, 2,362,598, 2,367,531, 2,369.929, 2,423,730, 2,474,293, 2,476,008, 2,498,466, 2,545,687, 2,728,660, 2,772,162, 2,895,826, 2,976,146, 3,002,836, 3,419,390, 3,446,622, 3,476,563, 3,737,316, 3,758,308, and 3,839,044, Britich Patents Nos. 4,78,991, 945,542, 1,084,480, 1,377,233, 1,388,024, and 1,543,040, and Japanese Published Unexamined patent Application Nos 47-37425, 50-10135, 50-130441, 51-6551, 51-37647, 51-52828, 51-108841, 53-109630, 54-48237, 54-66129, 54-131931, and 55-32071. Couplers capable of forming a coupling product having a maximal spectral absorption wavelength in a wavelength region of 700nm to 850nm are mentioned in Japanese Published Examined patent Application No. 52-24849, and Japanese Published Unexamined Patent Application Nos. 53-125836, 53-129036, 55-21094, 55-21095, and 55-21096. The coupler may be incorporated into a silver halide emulsion by using a high boiling point organic solvent and a dispersing agent. Various compounds may be contained in the silver halide photosensitive material of the invention in order to inhibit fogging during manufacture or storing, or in the process of development, or to stabilize the photographic performance of the material. For example, any of the following may be added: tetrazinedenes, azoles, such as benzothiazolium salts, nitroindazoles, nitrobenzoimidazoles, chlorobenzoimidazoles, bromobenzoimidazoles, memercaptothiazoles, mercaptobenzoimidazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (more specifically, 1-phenyl-5-mercaptotetrazole); mercaptopyrimidines, mercaptotriazines including oxazolithione and similar compounds; and various other compounds known as antifoggants or stabilizers, such as benzene thiosulfonic acid, benzenesulfonic acid, benzenesulfonamide, hydroquinone derivatives, aminophenol derivatives, gallic acid derivatives, and ascorbic acid derivatives. Hydrophilic colloids useful for forming a hydrophilic colloidal layer in the silver halide photosensitive material of the invention are not particularly limited. For example, gelatin and various other colloids may be used as binders for photosensitive and nonphotosensitive layers as required. Besides gelatin, the following may be used; colloidal albumin, agar-agar, gum arabic, dextrin, alginic acid, cellulose derivative, such as a cellulose acetate hydrolyzed to an acetyl content of 19 - 26%, for example, polyacrylamide, imidized polyacrylamide, casein, urethane carboxylic acid group, such as vinylalcohol-vinyl cyanoacetate copolymer or vinylalcohol copolymer containing a cyanoacetyl group, polyvinylalcohol-polyvinylpyrolidone, hydrolyzed polyvinyl acetate, a polymer produced by polymerization of a protein or a saturated protein acylate with a monomer having a vinyl group, polyvinyl pyridine, polyvinyl amine, polyamine ethylmethacrylate, and polyethylene imine. Any suitable compound may be used as a hardening agent. For example, organic hardening agents such as vinylsulfone, hardeners containing an acryloyl group, or ethylene imine and/or inorganic hardening agents such as chrome alum or potassium alum, or a combination of two or more agents may be used. The photosensitive material of the invention may contain a surface active agent for coat assisting, antistatic, emulsion dispersing, slip facilitating, emulsion dispersing, and adhesion inhibiting purposes, for example. Surface active agents useful for these purposes include, for example, saponin, sodium dodecylbenzene sulfonate, sodium sulfosuccinate, and also those mentioned in JP-A-49-46733, 49-10722, and 50-16525. Further, as a ultraviolet light absorber, it is possible to use compounds such as benzotriazoles, thiazolidones, acrylonitriles and benzophenones. In addition, antistatic, optical bleaching, antioxidant, and stainproofing agents may be used as required. In order to obtain the photosensitive material produced in accordance with the invention, a photographic additive is incorporated into the silver halide emulsion, and then a silver halide emulsion layer is formed on a base. In this case, if desired, a subbing layer and an intermediate layer may be formed between the base and the silver halide emulsion layer. Materials useful for the base include, for example, paper, glass, cellulose acetate, cellulose nitrate, polyester, polyamide, and polystyrene. Bonded materials consisting of a laminate of two or more kinds of base materials, such as, for example, paper and olefin (e.g., polyethylene or polypropylene), may also be used. In order to assure improved bonding between the base and the silver halide emulsion layer, the base material is generally subjected to various sorts of surface treatment, such as electron bombardment treatment and subbing treatment for the formation of a subbing layer. In order to coat a photographic silver halide emulsion on the base and allow it to dry, a generally known coating method, such as dip coating, roller coating, bead coating, or curtain flow coating, is employed. Coating is followed by drying. The photosensitive material may be developed by a conventional color development process. Color developing agents useful for color development inculde aromatic primary amine compounds, such as, for example, N-diethyl-p-phenylene diamine, N-ethyl-N-hydroxyethyl paraphenylene diamine, 4-(N-ethyl-N-hydroxyethyl) amino-2-methylaniline, 4-(N-ethyl-N-β-methanesulfone amide ethyl) amino-2-methylaniline, 4-(N, N-diethyl) amino-2-methylaniline, and 4-(N-ethyl-N- methoxyethyl) amino-2-methylaniline, and their sulfates, hydrochlorides, sulfites, and p-toluene sulfonates. A rapid color developer in particular may contain various developer additives in addition to aforesaid color developing agent and an N, N-dialkyl hydroxylamine salt as a preserver. For example, alkaline agents, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metaborate, and tribasic potassium phosphate, pH buffers, such as sodium phosphate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, and potassium bicarbonate, and organic solvents, such as methanol, ethyleneglycol, and triethanolamine, may selectively be used as required. The color developing solution may contain benzyl alcohol as a color improver, but preferably it contains no such agent. The solution may contain a small amount of a color improver. In that case, the amount of benzyl alcohol in the color developing solution is preferably 0 to 5 mℓ per liter of the solution, more preferably 0 to 3 mℓ. In order to improve the preservability of the color developing solution, it is particularly desirable to use sulfites, such as sodium sulfite and potassium sulfite, in combination with N, N-dialkylhydroxylamine in the solution. The sulfite is used preferably in the proportion of 0.05 g to 12 g per liter of the solution, more preferably 0.1 g to 0.3 g. If a water-soluble bromide is contained as a development restrainer in the color developing solution, it should preferably be present in a minimal amount. The solution may contain a small amount of bromide, but most preferably it contains no bromide. The term"rapid processing" generally means that the time taken for color development is less than 90 seconds. The temperature of the color developing solution is generally within the range of 20°C to 50 °C, preferably 30 °C to 40 °C. In rapid processing, it is necessary that after a dye image is formed, undeveloped silver halide and developed image silver are removed by bleach-fixing. The time for bleach-fixing is preferably less than 90 seconds, more preferably less than 60 seconds. Preferred bleaching agents for developed silver are polymetallic salts of organic acids. Examples of such polymetallic salts are ferric salts of organic acids for example, ferric salts of nitrilotriacetic acid, diethylenetriaminepentaacetic acid, ethyleneglycol-bis (aminoethylether) tetraacetic acid, diaminopropanoltetraacetic acid, N-(2-hydroxyethyl) ethylenediaminetriacetic acid, ethyliminodipropionic acid, cyclohexanediaminetetraacetic acid, or ethylenediaminetetraacetic acid. Ferric salts of polycarboxylic acids as mentioned in JP-A-49-107737 may also be used, which include, for example, salts of oxalic acid, malonic acid, succinic acid, tartaric acid, malic acid, tartaric acid, citric acid, and salicylic acid. Among polymetallic salts useful for the purpose of the invention are cupric salts and cobalt (II) salts in addition to aforesaid ferric salts. Further, inorganic polymetallic acids, such as ferric chloride and ferric sulfate, may be used depending upon the intended object. For the purpose of fixation, known agents, such as thiosulfate and thiocyanate, may be contained in the solution. Also, water soluble alkaline metallic salts, or bromides or iodides of ammonium, may be used as described in JP-A-48-101934, which mentioneds potassium bromide, ammonium bromide, sodium iodide for this purpose. In combination with the process of color development and bleach-fixing, such other processing stages as prehardening, neutralizing, washing, and stabilization may be carried out as required. EXAMPLE The following examples are given to further illustrate the invention. Example 1 A silver halide emulsion composed of silver chlorobromide grains having a mean grain diameter of 0.6 µm and a uniform silver chloride content of 10 mol% [Em-I] was prepared by a simultaneous mixing method. Next, a silver halide emulsion composed of silver chlorobromide grains having a mean grain diameter of 0.6 µm and uniformly containing 3 mol% of silver bromide [Em-2] was prepared by same mixing method. These emulsions, [Em-1] and [Em-2], were respectively divided into parts and, as shown in Table 1, sodium thiosulfate, diphenyl thiourea, sodium thiosulfate + gold compound, and diphenyl thiourea + gold compound were added to said parts of [Em-1] and [Em-2]. Ripening was effected until a maximal sensitivity was reached. Subsequently, 3 x 10⁻⁴ mol/AgX of a spectral sensitizing dye was added and then an antifoggant and a stablizer were added. Then, (Y-2), a yellow coupler, was added. On a resin coated base an emulsion layer was placed so that the emulsion coat comprised 4.0 mg/dm² of metallic silver, 30 mg/dm² of gelatin, and 0.75 g/ m² yellow coupler. A protective layer was formed on the emulsion layer by placing a 10 mg/dm² coat of gelatin thereon. Thus, test samples were prepared. These samples were subjected to light intensity scale exposure by a conventional method. Then, color development was carried out under the conditions indicated below. With the dye images thus obtained, density measurements were made by employing a PDA-65 densitometer (made by Konishiroku Photo Industry Co., Ltd.) through a blue filter. Results are shown in Table 1. In the Table, γ₂ represents gradation under a reflection desity of 0.2 - 0.7 (gradation at toe), and γ₁ represents gradation under a reflection density of 0.7 - 2.0 (gradation at shoulder). Sensitivity values in Table 1 refer to relative sensitivity values and correspond to values calculated relative to the sensitivity in the color development of sample No. 105 under processing mode A which is taken as 100. Processing stages are mentioned below. Processing was carried out under two different modes, [A] (3 min development) and [B] (45 s development): Compositions of the color developing and bleach/fix solutions used are shown below. Color Developing Solution: A B Pure water 800 mℓ 800 mℓ Ethylene glycol 15 mℓ - Benzyl alcohol 15 mℓ - N, N-diethylhydroxylamine - 6 mℓ Potassium chloride 2.0 g 2.0 g Potassium brimide 0.8 g - Potassium sulfite 2 g 0.2 g N-ethyl-N-β-metasulfoneamide ethyl-3-methyl-4-amino aniline sulfate 5 g 5 g Tetrasodium polyphosphate 2 g 2 g Potassium carbonate 30 g 30 g Triethanolamine - 8.3 g Distilled water was added until the quantity of the solution reached 1 ℓ. pH was adjusted to 10.08. Bleach/Fix Solution: Pure water 800 mℓ Ethylenediaminetetra iron acetate (III) Ammonium 65 g Ethylenediaminetetraacetic acid -2-Sodium 5 g Ammonium thiosulfate 85 g Sodium bisulfite 10 g Sodium metabisulfite 2 g Sodium chloride 10 g Hydroxylamine sulfate 2 g Distilled water was added until the quantity of the solution reaches 1 ℓ. pH was adjusted to 7.0 with dilute sulfuric acid. However, if processing was carried out with B developing solution, a bleach/fix solution of which pH had been adjusted to 6.2 was used. The following facts can be seen from Table 1. Referring to test piece Nos. 101 - 108 using Em-1 emulsion having a high silver bromide content, those in which reference spectral sensitizing dyes A, B, C were used (sample Nos. 101 - 103) showed low sensitivity values, but those using spectral sensitizing dyes of formula [I] (sample Nos. 104 - 108) showed high sensitivity values. In the latter mentioned cases, the γ₁, γ₂ values showed satisfactory gradation. However, the results of 45 s rapid processing (in the present instance, a developing solution containing no benzyl alcohol was used) show that sensitivity values decreased further with sample Nos 101 - 103, and those of sample Nos. 104 - 108 also dropped noticeably. They all showed soft gradation and no satisfactory image was obtained. No doubt, with an emulsion having such a high silver bromide content, rapid processing could not obtain any satisfactory image. Where such an emulsion is used, therefore, it is impracticable to carry out rapid processing. With samples using emulsion Em-2 having a silver chloride content of 97% mol%, it was found that where they contained reference spectral sensitizing dyes A, B, C (sample Nos. 109 - 111), their sensitivity was low even after 3 min development and their γ₁, γ₂ values were lower than those of sample Nos. 101 - 103, showing soft gradation. However, 45 s development of test piece Nos. 109 - 111 showed no such change in either sensitivity or gradation compared with the case of 3 min development, though there was some slight variation. There was no particular indication of a performance drop due to rapid development. It can be seen from this that an emulsion having a high silver bromide content is suitable for rapid processing, though it is likely to cause soft gradation. With test piece Nos. 112 - 117 using emulsion Em-2 with spectral sensitizing dyes of formula [I], it is clear from the 3 min processing data that fairly high sensitivity values were obtained, but they showed much lower gradation than those containing reference sensitizing dyes (sample Nos. 109 - 111). Results of 45 s processing showed that their γ₁, γ₂ values were lower than those of test piece Nos. 109 - 111, which means softer gradation. Thus, it can be seen that it is possible to obtain high sensitivity on one hand by incorporating a spectral sensitizing dye into an emulsion having a high silver chloride content, but on the other hand it is apparent that it results in lowered gradation. Sample Nos. 118 and 119 used emulsion Em-2 containing reference sensitizing dye C and gold chloride. A comparison of these samples with sample No. 111 shows that the presence of the gold compound can give some improvement in γ₁, γ₂ thus producing a somewhat higher contrast. However, sensitivity remains low. Sample Nos. 120 - 131 represent the present invention. As can be clearly seen from a comparison of these pieces with test piece Nos. 118, 119, the test pieces of the invention have an advantage in the degree of improvement in γ₁, γ₂ values due to the presence of the gold compound. Thus, the greater high contrast effect of the gold compound can be obtained when spectral sensitizing dyes of formula [I] are used. Furthermore, the samples of the invention showed much higher sensitivity since they incorporated compounds of formula [I]. On the other hand, no soft gradation effect was seen with sample Nos. 120 - 131, and γ₁, γ₂ values of the test pieces in the case of 3 min processing compared well to those of sample Nos. 101 - 108 in 3 min processing. Moreover, when 45 s rapid processing was carried out, the samples of the invention showed almost no change in either sensitivity or gradation, proving their suitability for rapid processing. As described above, according to the invention, it is possible to obtain high sensitivity by incorporating a spectral sensitizing dye of formula [I] and a sulfur sensitizing agent into an emulsion having a high silver chloride content, and further to restrain, by using a gold compound, such soft gradation tendency as may otherwise occur when any spectral sensitizing dye of the general formula [I] is used in an emulsion having a high silver chloride content. Thus, it is clear that the photosensitive material of the invention is rapidly processable, highly sensitive, and is free from gradation lowering. Sample No. 132 has a larger amount of gold compound than specified by the invention. The test results show that it is less sensitive and produces excessively high contrast gradation. Therefore, it cannot provide any satisfactory image. Sample No. 133 shows the opposite case, that is, it has an excessively small amount of gold compound. The image obtained is of excessively low gradation. Reference compounds Example 2 Samples were prepared which were same as sample Nos. 120, 127 using emulsion Em-2 in Example 1 except that yellow coupler CY-1 was used instead of yellow coupler Y-1 in samples 120, 127. The samples so prepared were referred to as samples 201, 202. With these samples, color development was carried out using color developing solution P-2 (which did not contain benzyl alcohol) and another color development solution comprising 15 mℓ of benzyl alcohol added to the ingredients of developer A respectively. Reflective maximum density (Dmax) was measured by employing the same densitomer as used in Example 1. Results are shown in Table 2. It can be seen that, compared with yellow coupler (Y-1) used in Example 1, CY-1 coupler is less likely to give high Dmax in the one color developing solution which contained no benzyl alcohol (hereinafter referred to as BeOH). With sample Nos. 203 and 204 using (Y-1) yellow coupler (in the same way as sample Nos. 120, 127 in Example 1), it was found that the same degree of sensity was attained as by samples 201, 202 (using CY-1) when BeOH was used could be attained even if BeOH was not used. Further it was found that test pieces 203, 204 (Nos. 120, 127) could give a higher color dye image density in a color developing solution in which BeOH was used. In samples 205 - 209 yellow couplers Y-4, Y-39, Y-6, Y-43 or Y-43 were each substituted for yellow coupler (Y-1) in sample 204 (sample 127 in Example 1). A tendency similar to the one observed with samples 203, 204 was seen with samples 205 - 209. Example 3 Ripening was carried out with emulsion Em-2 by using the sodium thiosulfate in Table 3. Then, 3 x 10⁻⁴ mol/Ag mol of the spectral sensitizing dye [I-1] was added. Successively thereafter, a gold compound (e.g., gold chloride) was added in such amount as shown in Table 3 and the emulsion was subjected to ripening for 10 min. An antifoggant and a stabilizer were added. The same coupler as used in Example 1 was then added, and sample Nos. 301 - 305 in Table 3 were thus prepared. After subjected to exposure, the test pieces were processed for development with (B) developing solution (containing neither benzyl alcohol nor potassium bromide). Measurements were made in the same way as in Example 1. Results are shown in Table 3. Sample No. Emulsion Sodium thiosulfate mol/AgX mol Gold chloride mol/AgX mol Sensitivity, gradation due to color develop solution P-2 Sensitivity γ₁ γ₂ 301 Em-2 3.5 x 10⁻⁶ - 110 3.40 2.20 302 Em-2 3.5 x 10⁻⁶ 3 x 10⁻⁶ 110 3.85 2.75 303 Em-2 3.5 x 10⁻⁶ 2 x 10⁻⁶ 110 3.83 2.72 304 Em-2 3.5 x 10⁻⁶ 5 x 10⁻⁸ 110 3.45 2.25 305 Em-2 3.5 x 10⁻⁶ 8 x 10⁻³ 90 3.95 3.10 As is apparent from Table 3, any gold compound used in the invention, if not subjected to ripening in conjunction with a yellow sensitizer, can produce the same effect as was observed in Example 1 by being added to the emulsion in such amount as specified by the invention. Apparently the presence of such an amount of gold compound serves to positively compensate the negative effect on gradation of the developing solution which contains no potassium bromide or BeOH (sample Nos. 302 and 303). Example 4 Dye [I] was used in same way as in sample 302 in Example 3, except that proportions of the dye were varied as shown in Table 4. As can be seen clearly from the test results of sample Nos 401 - 403, no sensitivity drop could be found with the photosensitive material of the invention when the dye was used within the quantity range specified, the test pieces showing good performance in both gradation and sensitivity. With sample No. 404, in which the quantity of the dye exceeded the permissible quantity range, even the addition of gold compound did not serve to recover good gradation. With sample No. 405, in which the quantity of the dye is lower than the lowest quantity limit of the invention, there was no downward change in gradation, but a considerable drop in sensitivity was observed. Sable No. Spectral sensitizing dye sensitivity, gradation due to processing with B solution Sensitivity γ₁ γ₂ 401 3 x 10⁻⁴ 110 3.85 2.75 402 5 x 10⁻⁵ 110 3.85 2.75 403 1 x 10⁻³ 110 3.86 2.75 404 x 10⁻³ 110 3.40 2.25 405 9 x 10⁻⁷ 50 3.85 2.75 Example 5 According to a conventional technique, the silver chlorobromide emulsion with the halogen composition in the following Table 5 was prepared by the double jet precipitation method. Emulsion No. Br : Cℓ ratio (µm) average grain size Chemical sensitizer Spectral sensitizing dye (0.9 mg per mol Ag) Em-1 5 : 95 0.67 Sodium thiosulfate - Comparison compound BSD-1 Em-2 5 : 95 0.67 Sodium thiosulfate Sodium chloroaurate Comparison compound BSD-1 Em-3 5 : 95 0.67 Sodium thiosulfate - Example compound I-1 Em-4 5 : 95 0.67 Sodium thiosulfate Sodium chloroaurate Example compound I-1 Em-5 5 : 95 0.67 Sodium thiosulfate Sodium chloroaurate Example compound I-5 Em-6 5 : 95 0.67 Sodium thiosulfate Sodium chloroaurate Example compound I-10 Chemical sensitization was optimized by maintaining each silver halide emulsion at 60 °C and adding 1.5 mg thiosulfate and 3 mg sodium chloroaurate per mol silver. Then, using the spectral sensitizing dyes listed in Table 5, spectral sensitization was effected, whereby 4-hydroxy-6-methyl-1,3,3a;7-tetrazaindene serving as a stabilizer was added into each emulsion at a rate of one g per mol silver halide. Next, the following layers 1 through 7 were formed in sequence (by a simultaneous coating process) on each paper support where both surfaces had been coated with polyethylene to prepare silver halide color photographic light sensitive material samples No. 501 through 515 (in the following examples, the amount of materials is indicated by the amount per m² lightsensitive material). Layer 1 A layer containing, as listed in Table 6, gelatin (1.2 g), 0.29 g (silver converted value, applicable hereinunder) bluesensitive silver chloro-bromide emulsion (Em-1 to Em-6) and 2 mg of black-and white developing agent in addition, 0.3 g dinonylphthalate (DNP) in which 0.75 g yellow coupler (example compound, Y-52), 0.3 g light-stabilizer ST-1 and 0.015 g 2,5-dioctylhydroquinone (HQ-1) had been dissolved. Layer 2 A layer containing gelatin (0.9 g), 0.2 g DOP (dioctylphthalate) in which 0.04 g HQ-1 had been dissolved , 8 mg anti-irradiation dye (AI-1) and 4 mg antiirradiation dye (AI-2). Layer 3 A layer containing 1.25 g gelatin, 0.20 g green-sensitive silver chloro-bromide emulsion (with a Br : Cℓ ratio of 5 : 95), as well as 0.3 g DOP in which 0.62 g magenta coupler (M-1) and 0.01 g HQ- 1 had been dissolved. Layer 4 A layer containing gelatin (1.2 g), as well as 0.3 g DNP in which 0.6 g ultraviolet absorbent UV-1 (below), and 0.05 g HQ-1 (below) had been dissolved. Layer 5 A layer containing gelatin (1.4 g), 0.20 g red-sensitive silver chloro-bromide emulsion (with a Br : Cℓ ratio of 5 : 95), as well as 0.3 g DOP in which 0.5 g cyan coupler C-1 and 0.01 g HQ-1 had been dissolved. Layer 6 A layer containing gelatin (1.0 g) and 0.05 g 2,4-dichloro-6-hydroxyl sodium. Comparison sensitizing dye (Note-1): Green-sensitive silver chloro-bromide emulsion Sodium thiosulfate was added into the emulsion at a rate of 3.5 x 10⁻⁵ mol per mol silver halide in order to effect the chemical sensitization, whereby the optical sensitization was effected with green sensitizing dye (GSD-1). Also, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene compound serving as a stabilizing agent was added into the emulsion at a rate of 1.2 g per mol silver halide. (Note-2): Red-sensitive silver chloro-bromide emulsion Sodium thiosulfate was added into the emulsion at a rate of 3.5 x 10⁻³ mol per mol silver halide in order to effect the chemical sensitization, whereby the optical sensitization was effected with red sensitizing dye (RSD-1). Also, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene compound serving as a stabilizing agent was added into the emulsion at a rate of 1.2 g per mol silver halide. Each of the above samples of light sensitive materials No. 501 through 515 was exposed through the optical wedge and then treated by the following processes: Processing steps (35 °C) Color developing 45 s Bleach-fixing 45 s Stabilization 1 min 30 s Drying 60 to 80 °C 2 min The composition of each processing solution is as follows: Color developer: Pure water 800 mℓ N, N-diethylhydroxylamine 2 mℓ Potassium chloride 2 g Potassium sulfite 0.2 g N-Ethyl-N-β-methanesulfonamidethyl-3-methyl-4-aminoaniline sulfate 5 g Sodium tetrapolyphosphate 2 g Potassium carbonate 30 g Pure water was added to the above ingredients to prepare 1 ℓ of the solution, which was adjusted to a pH of 10.08. Bleach-fixer: Pure water 800 mℓ Ammonium ferric (III) ethylenediaminetetraacetate 65 g Bisodium ethylenediaminetetraacetate 5 g Ammonium thiosulfate 85 g Sodium hydrogensulfine 10 g Sodium metabisulfite 2 g Sodium chloride 10 g Hydroxylamine sulfate 2 g Pure water was added to the above ingredients to prepare 1 ℓ of the solution, which was treated with dilute sulfuric acid to adjust the pH to 7.0. Stabilizer 5-Chloro-2-methyl-4-isothiazoline-3-one 1 g 1-Hydroxyethylidene-1,1-diphosphonic acid 2 g Pure water was added to the above ingredients to prepare 1 ℓ of the solution, which was treated with sulfuric acid or potassium hydroxide to adjust the pH to 7.0. In addition, a color developer was prepared by adding 0.3 mℓ-0.6 mℓ of the bleach-fixer per liter of the above color developer. In Table 6, the amount of addition is represented as the amount of contaminant, and the amount in fact corresponds to the degree of contamination of the developer solution by bleach-fixer in practical processing, whereby the sensitometry was exercised on each of the similarly treated samples in order to determine the sensitivity, gradation, and fog of blue-sensitive emulsion layer. The results are listed in Table 6. The results in Table 6 show that samples No. 501 and No. 502 , comparison samples, respectively containing both sulfur sensitizer and spectral sensitizing dye have low sensitivities which are not improved even by addition of the black-and-white developing agent. Apparently, samples tested after application of sensitization, No. 503 and No. 504, or samples containing spectral sensitizing dye instead of the example compound representing the invention No. 505 and No. 506, indicate larger Δγ, though having improved sensitivities, which means the enlarged performance fluctuation is due to processing fluctuation. In contrast, each of the samples Nos. 508, 509, 511, 512, 514, and 515 is highly sensitive, and shows low fog and small Δγ, and is stable to the fluctuation in processing conditions by contamination of the developer. Though respectively having emulsions Em-3, Em-4 and Em-5, each of the samples Nos. 507, 510 and 513 indicates high fog and large Δγ when the developer is contaminated. Example 6 Samples of Example 5 were allowed to stand for five days under the conditions of 50 °C and 70% RH for forced deterioration. With each sample, treatment was identical to that of Example 5, except that the developing time was modified to 45 seconds or one minute 15 seconds instead of the contamination test conditions, so as to assess the shelf life of each sample. The results are listed in Table 7. The results in Table 7 illustrate that the samples No. 501 and No. 502, comparison samples, show significantly decreased sensitivities after the forced deterioration, and that the samples No. 503 through No. 507, though having high sensitivitties, had significantly decreased sensitivities after the forced deterioration. In contrast, each of the samples Nos. 508, 509, 511, 512, 514 and 515 is excellent; each featuring high sensitivity, low fog, and limited sensitivity loss even after the forced deterioration. At the same time, the comparison samples Nos. 507, 510 and 153 independently show high fog and low stability to the fluctuation in processing conditions: there is a difference between a postdeterioration sample treated for 45 seconds and a similar sample treated for one minute 15 seconds. Example 7 By a preparation method identical to that of Example 1, silver halide emulsions Em-9 through Em-11 each having silver halide grains and spectral sensitizing dye listed in Table 8 were prepared. Emulsion No. Br : Cℓ ratio (µm) average grain size Chemical sensitizer Spectral sensitizing dye (0.9 mmol per mol Ag) Em-9 1 : 99 0.71 Sodium thiosulfate Sodium chloroaurate I-2 Em-10 1 : 99 0.71 Sodium thiosulfate Sodium chloroaurate I-6 Em-11 1 : 99 0.71 Sodium thiosulfate Sodium chloroaurate I-18 Using these emulsions, and by replacing the yellow coupler in the layer constitution of Example 5 with yellow coupler Y-53, as well as by replacing the black-and white developing agent in Example 5 with the compound listed in Table 9, silver halide color photographic light-sensitive materials were prepared. With the obtained samples, a test identical to that of Example 5 was exercised. The test results are listed in Table 9. Sample Nos. 505 and No. 506 in Example 5 were used as comparison samples, listed as samples No. 716 and No. 717 in Table 9. Table 9 illustrating this example also provides results similar to those of Example 5. With the samples No. 716 through No. 719 of this example, a test identical to that of Example 6 was exercised, and results similar to those of Example 6 were obtained. Example 8 With the samples of Example 7, a bleach-fixer contamination test identical to that in Example 5, as well as a forced deterioration identical to that in Example 6 were exercised, whereby the sensitivity and gradation fluctuation were measured for each of the samples. The results measured were compared with the sensitometric values of other green-sensitive layers and red-sensitive layers. As a result, it was learned that in the samples containing the black-and-white developing agent various fluctuation factors were improved, the sensitivity and gradation of the blue sensitive layer matching those of the other layers well. Example 9 As shown in Table 6, two samples were prepared in the same manner as in Example 5 except that the black-and-white agent was replaced. One sample was developed immediately after being prepared, and the other was stored for 5 days under the conditions of 50 °C and 70% RH, then exposed and developed. The effect of the present invention that the characteristic fluctuation after being forcedly deteriorated was small was proved as shown in Table 10. In addition, it was also proved that hydroxybenzene derivatives were effective in suppressing fogging. Example 10 Into a well-stirred gelatin solution, 0.5 ℓ of silver nitrate solution of 2 mol/liter and 0.5 ℓ of sodium chloride solution of 2 mol/liter were added over a period of 150 min., thus obtaining a pure silver chloride emulsion Em-12. During the addition, the solution temperature was maintained at 60°C, and PAg at 6.0. An electron microscope observation revealed that the average grain size of the obtained emulsion was 0.65 µ and crystalline shape was cubic. By replacing the sodium chloride solution with a mixed silver halide solution containing 0.995 mol of sodium chloride and 0.005 mol of potassium bromide, silver chloro-bromide emulsion Em-13 containing 0.5 mol of silver bromide was prepared using the same manner as that used to prepare Em-12. The average grain size of the emulsion obtained was 0.65 µm and the crystalline shape was cubic. By replacing the sodium chloride solution with a mixed silver halide solution containing 0.975 mol of sodium chloride and 0.025 mol of potassium bromide, silver chloro-bromide emulsion Em-12 containing 2.5 mol of silver bromide was prepared using the same manner as that used to prepare Em-14. The average grain size of the emulsion obtained was 0.65 µm and the crystalline shape was cubic. Sodium thiosulfate was added as a sulfur sensitizing agent into emulsions Em-12 to Em-14 in an amount of 1 x 10⁻⁵ mol per mol of silver halide. Then 2 x 10⁻⁵ mol of chloroauric acid was added, then the obtained solution was chemically ripened. Sensitizing dye I-22 shown above was added 5 min before the end of the ripening process in an amount of 10⁻⁴ mol per mol of silver halide, stabilizer ST-1 was added at the end of the ripening process in an amount of 10⁻³ mol per mol of silver halide, thus preparing a blue-sensitive silver halide emulsion. Yellow coupler Y-44 shown above, and 0.15 mol of anti-stain agent HQ-1 per 1 mol of the yellow coupler, both of which were dispersed in dibutylphthalate (hereinafter referred to as DBP) were mixed into the blue-sensitive silver halide emulsion so that 0.3 mol of the coupler was obtained per mol of silver halide. The coating solution thus prepared was applied onto photographic support coated with polyethylene containing titanium oxide. Further, a protective layer was applied onto the support, thereby obtaining the samples. The quantity of silver halide or gelatin contained in each layer applied was adjusted so that 0.4 g/m² of metallic silver and 3.0 g/m² of gelatin in the emulsion layer and 1 g/m² of gelatin in the protective layer were obtained. Each sample was subjected to the light intensity scale exposure and to the following processes: (Processing step) Color developing 35°C 45 s Bleach-fixing 35°C 45 s Water rinsing 30 to 35°C 90 s Drying 60 to 68°C 60 s The composition of the color developer and bleach-fixer used were as follows (Quantities are given per one liter solution.): Color developer: Pure water 800 mℓ Triethanolamine 12 mℓ N,N-diethylhydroxylamine (85% solution) 12 mℓ Potassium chloride 2.2 g Potassium sulfite 0.2 g N-ethyl-N-β-methanesulfonamidethyl-3-methyl-4-aminoaniline sulfate 5.0 g 1-Hydroxyethylidene-1-1-diphosphonate 1.0 g Ethylenediaminetetraacetic acid 2 g Soluble fluorescent whitening agent of the diaminostilbene system 2 g Pure water was added to the above mixture to obtain one liter of solution, which was adjusted to pH 10.1. Bleach-fixer: Pure water 800 mℓ Ammonium ferric (III) ethylenediaminetetraacetate 65 g Bisodium ethylenediaminetetraacetate 5 g Ammonium thiosulfate 85 g Sodium hydrogensulfine 10 g Sodium metabissulfite 2 g Sodium chloride 10 g N,N-diethylhydroxylamine (85% w:v solution) 2 mℓ Pure water was added to the above mixture to obtain one liter of solution, which was adjusted to pH 6.5 using dilute sulfuric acid. The reflection density of the dye images obtained was measured using a PDA-65 densitometer (manufactured by Konishiroku Photo Industry Co., Ltd.) and using monochromatic blue light, thereby obtaining the results listed in Table 11. In this table, the sensitivity is represented by a reciprocal of the exposure quantity which gives a density of 1.0, at the same time, by a relative value relative to the 100% sensitivity of Sample 1001. No. Emulsion Sensitivity Minimum density Maximum density 1001 Em-12 100 0.08 2.60 1002 Em-13 132 0.06 2.58 1003 Em-14 85 0.09 2.53 Sample 1002, which employed the silver halide emulsion Em-13 containing 0.5 mol% of silver bromide, was of high-sensitivity and low in minimum density, and its maximum density was equivalent to that of the Em-12. In comparison, the maximum density of Sample 1003, which used the silver halide emulsion Em-14 containing slightly more silver bromide, slightly deteriorated, its sensitivity obtained after the chemical ripening step is lower than that of the Em-12, and its minimum density is a little higher than that of Em-12. Example 11 Em-15 and Em-16 were prepared in the same manner as that described for Em-12 in Example 10 but changing the amount of silver halide to 10 mol and 1000 mol respectively. Next, Em-17 and Em-18 were prepared in the same manner as that described for Em-13 but changing the amount of silver halide to 10 mol and 1000 mol respectively. The average grain size of each emulsion was 0.65 µm and the crystalline shape was cubic. In the emulsion preparing method used in Example 10, 0.0025 ℓ of a 2 mol/ℓ potassium bromide solution was added instead of a 2 mol/ℓ sodium chloride solution after adding 0.4975 ℓ of silver nitrate solution, thereby obtaining silver chloro-bromide emulsion Em-19. Em-20 and Em-21 were prepared in the same manner as that described above but changing the amount of silver halide to 10 mol and 1000 mol respectively. The average grain size of the emulsion was 0.65 µm and the crystalline shape was cubic. Each emulsion from Em-15 through Em-21 thus prepared was subjected to the chemical ripening, application, and characteristic evaluation steps in the same manner as described in Example 10. The results obtained are listed in Table 12. The sensitivity of each sample is represented by a relative value relative to the 100% sensitivity of Sample 1101. No. Silver halide emulsion Sensitivity Minimum density Maximum density 1101 Em-12 100 0.09 2.62 1102 Em-15 87 0.12 2.63 1103 Em-16 97 0.10 2.63 1104 Em-13 130 0.06 2.59 1105 Em-17 135 0.07 2.57 1106 Em-18 138 0.06 2.60 1107 Em-19 154 0.06 2.58 1108 Em-20 162 0.06 2.56 1109 Em-21 169 0.07 2.57 Each silver halide emulsion obtained by preparation amount scale of 1 mol, 10 mol, and 1000 mol was exactly equivalent under the observation with an electron microscope. However, the evaluation of photographic characteristics of each emulsion after chemical ripening step revealed that the sensitivity fluctuation of Em-13, 17, 18, 19, and 20, in which the contents of silver halide were within a range from 99.0 mol% through 99.5 mol%, was only approximately 3 to 4%. In contrast, Em-12, 15, and 16 showed a sensitivity fluctuation of approximately 6% and an increase in the minimum density. A high sensitivity and a low minimum density in a silver halide color photographic light-sensitive material using an emulsion containing silver chloride from 99.0 to 99.5 mol% were reproduced in all samples irrespective of manufacturing lot. Preferably silver bromide, which is slightly effective in order to stabilize the photographic characteristics, is uniformly dispersed in the grain in an emulsion, in which silver bromide was formed at the final step for preparing the silver halide grain. Example 12 Samples were prepared in the same manner as that described in Example 10 except that the sensitizing dyes were replaced with the compounds listed in Table 13, and were subjected to the characteristic evaluation. The sensitivity of each sample is represented by a relative value relative to the 100% sensitivity of Sample 1201. The results shown in the table above reveal that the sensitizing dyes used in the present invention ensure a high sensitivity and a low minimum density by being combined with a silver halide emulsion containing a high content of chloride. Especially, dyes such as I-27, I-34, I-45, and I-47, which contain an alkyl radical substituted with a sulfo radical and an alkyl radical substituted with a carboxyl radical, showed a low minimum density, thereby being preferable. When the sensitizing dye used in the present invention is combined with the pure silver chloride emulsion Em-12, 15 or 16, the fluctuation in sensitivity caused by the preparation scale of the silver halide emulsion is apt to be larger than that when comparison dyes A or B are used. However, when the silver halide emulsion containing silver chloride from 99.0 to 99.5 mol% is used, the fluctuation is improved to the same level as that of comparison dye A or B. In addition, the features of a high sensitivity and a low minimum density are not lost. When comparison dyes C, D, or E having a naphthothiazole nucleus are used, a high sensitivity is obtained by comparison dye C or E. However, the fluctuation in sensitivity caused by the preparation scale of the silver halide emulsion cannot be improved by combining Em-13, 17, or 18, which contain 0.5 mol% silver bromide. Moreover, when comparison dye D is used, the sensitivity is low and the fluctuation in sensitivity cannot be improved. Example 13 Samples were prepared in the same manner as that used in Example 10 except that only sodium thiosulfate was added as the sensitizing agent, and were subjected to the characteristic evaluation The sensitivity of each sample is represented by a relative value relative to the 100% sensitivity of Sample 1301. No. Silver halide emulsion Chloroauric acid Sensitivity Minimum density Maximum density 1301 Em-12 Added 100 0.13 2.62 1302 Em-15 Added 90 0.12 2.61 1303 Em-16 Added 94 0.13 2.63 1304 Em-12 Not added 64 0.10 2.60 1305 Em-15 Not added 81 0.12 2.59 1306 Em-16 Not added 85 0.10 2.59 1307 Em-13 Added 139 0.06 2.59 1308 Em-17 Added 135 0.07 2.57 1309 Em-18 Added 131 0.06 2.59 1310 Em-13 Not added 109 0.07 2.57 1311 Em-17 Not added 99 0.07 2.55 1312 Em-18 Not added 102 0.08 2.56 The emulsion sensitized only by sulfur showed a low sensitivity and a large characteristic fluctuation, however, the sensitivity of emulsions is significantly improved and the characteristics are significantly stabilized by sensitizing with gold at the same time. Example 14 Silver chloride emulsion Em-22 and silver chloro-bromide emulsion Em-23 both having a grain size of 0.4 µm were prepared according to the preparation method described for Em-12 and Em-13 in Example 10. Sodium thiosulfate was added to these emulsions as a sulfur sensitizing agent, and chloroauric acid was further added, then each emulsion was subjected to the chemical ripening step, and divided into two parts. Sensitizing dye GS-1 was added to one part, and RS-1 was added to the other. Five minutes later, stabilizing agent ST-1 was added to both emulsions, thus terminating the chemical ripening step. Thus, green-sensitive emulsion containing GS-1 and red-sensitive emulsion containing RS-1 were prepared. Next, the following seven layers were applied and laminated in sequence onto polyethylene coated paper support. A silver halide color photographic light-sensitive material was obtained. The quantity of each chemical compound is represented in weight per 1 m² of color photographic light-sensitive material in the following description: (First layer) A silver halide emulsion layer containing 0.4 g of dibutylphthalate dispersion, to which 0.85 g of yellow coupler Y-44 and 0.015 g of anti-stain agent HQ-1 had been dissolved, a blue-sensitive emulsion in a quantity equivalent to 0.4 g of silver, and 2 g of gelatin. (Second layer) An intermediate layer containing 0.03 g of dibutylphthalate dispersion, into which 0.03 g of anti-stain agent HQ-1 had been dissolved, and 1 g of gelatin. (Third layer) A silver halide emulsion layer containing 0.34 g of tricresylphosphate dispersion, in which 0.63 g of magenta coupler MC-1 (shown below) and 0.015 g of anti-stain agent HQ-1 had been dissolved, a green-sensitive emulsion in a quantity equivalent to 0.4 g of silver, and 2 g of gelatin. (Fourth layer) An intermediate layer containing 0.5 g of dibutylphthalate dispersion, in which 0.03 g of anti-stain agent HQ-1 and 0.8 g of ultraviolet absorbing agent (described below) had been dissolved, and 0.15 g of gelatin. (Fifth layer) A silver halide emulsion layer containing 0.2 g of dioctylphthalate dispersion, in which 0.35 g of cyan coupler CC-1 and 0.015 g of anti-stain agent HQ-1 had been dissolved, a red-sensitive emulsion in a quantity equivalent to 0.30 g of silver, and 1.5 g of gelatin. (Sixth layer) An intermediate layer containing 0.3 g of dibutylphthalate dispersion, in which 0.4 g of ultraviolet absorbing agent had been dissolved, and 1 g of gelatin. (Seventh layer) Layer containing 1 g of gelatin. The color paper thus prepared was subjected to an exposure process through a color negative and to the color developing process used in Example 10. The exposure conditions were adjusted so that an optimum result was obtained for Sample 1401 or 1404. The exposure condition adjusted for Sample 1401 was applied to Samples 1405 and 1404, and the condition adjusted for Sample 1404 was applied to Samples 1405 and 1406. Color prints of Samples 1405 and 1406 equivalent to those of Samples 1401 and 1404 were obtained, however, the color print obtained from Sample 1402 was blueish. Thus, the characteristic fluctuation caused by manufacturing silver halide photographic light-sensitive materials using emulsions containing silver chloride from 99.0 to 99.5 mol% was limited to a very small value, thus enabling color prints to be obtained without substantially changing the color developing conditions.

Claims: A process for the preparation of a silver halide color photographic light sensitive material comprising a support having thereon at least one photographic component layer including at least one silver halide emulsion layer comprising: (a) silver halide grains comprising not less than 80 mol% of silver chloride, (b) a gold compound in an amount of from 5 x 10⁻⁷ to 5 x 10⁻³ mol per mol of silver halide contained in the silver halide emulsion layer, (c) a sulfur sensitizer, and (d) a spectral sensitizing dye of formula [I] in an amount of from 5 x 10⁻⁶ to 5 x 10⁻² mol per mol of silver halide contained in the silver halide emulsion layer: wherein X₁, X₂, X₃ and X₄ are, independently, hydrogen, halogen, alkyl, alkoxy, aryl or hydroxy; R₁ and R₂ are, independently, optionally substituted alkyl; X ⊖ is an anion and n is 0 or 1, which process comprises incorporating the sensitizing dye in the emulsion after the end of a first ripening stage and before the end of a second ripening stage. A process according to claim 1, wherein the silver halide grains comprise from 99.0 to 99.9 mol% of silver chloride. A process according to claim 1 or 2, wherein the silver halide grains are sensitized with from 1 x 10⁻⁶ to 1 x 10⁻⁴ mol gold compound per mol of silver halide contained in the silver halide emulsion layer. A process according to any one of the preceding claims, wherein the silver halide grains are sensitized with from 1 X 10⁻⁵ to 1 x 10⁻³ mol spectral sensitizing dye per mol of silver halide contained in the silver halide emulsion layer. A process according to any one of the preceding claims, wherein at least one of the photographic component layers comprises a black-and-white developing agent. A process according to claim 5, wherein the black-and-white developing agent is a dihydroxybenzene. A process according to any one of the preceding claims, wherein the silver halide emulsion layer comprises a yellow coupler of formula [Y]: wherein R₂₁ is a halogen or alkoxy; R₂₂ is -NHCOR₂₃SO₂R₂₄, -COOR₂₄, -COOR₂₃COOR₂₄, or in which R₂₃ is alkylene, R₂₄ is a ballast group and R₂₅ is alkyl, aralkyl or hydrogen; and Z₂₁ is a group capable of being split off in a reaction with an oxidized product of a color developing agent. A process according to any one of the preceding claims, wherein all the silver halide emulsion layers present comprise silver halide grains comprising not less than 80 mol% of silver chloride. A process according to claim 8, wherein the average silver chloride content of silver halide grains in each silver halide emulsion layer is not less than 95 mol%. A process according to any one of the preceding claims, wherein R₁ and R₂ are, independently, unsubstituted alkyl or alkyl substituted with carboxy or sulfo.

Inventors: KOJIMA, TAKAAKI, OHBAYASHI, KEIJI, OKUMURA, MITSUHIRO, TANAKA, SHIGEO
Applicants: KONICA CORPORATION
Application year: 1987
Main classification: G03C1
IPC codes: G03C1, G03C7