SILVER HALIDE PHOTOGRAPHIC LIGHT-SENSITIVE MATERIAL

Abstract: A photographic material having an excellent rapid processability, a high sensitivity and a less sensitivity variation due to a change of standing of the silver halide emulsion in the course of preparation of the light-sensitive material, and its preparation process are disclosed. The silver halide photographic light-sensitive material comprises a support bearing at least one silver halide emulsion layer thereon and at least one silver halide emulsion layer contains highly chloride-containing silver halide grains having a silver chloride content of not less than 90 mol%, a water-soluble bromide of from 0.05 mol% to 2 mol% per mol of silver halide and a high boiling organic solvent having a dielectric constant of not higher than 6.0.

Description: This invention relates to a silver halide photographic light-sensitive material which has exceptional rapid processability and has little sensitivity variation caused by a change on storage of the preparation of the light-sensitive material, and to the preparation process thereof. In recent years, rapid color processing has been demanded to improve the productivity of photographic prints. It is known that color development is accelerated when an exposed silver halide photographic light-sensitive material is developed with an aromatic primary amine type color developing agent. Color development acceleration studies have been made on compounds including, for example, those described in U.S. Patent Nos. 2,950,970, 2,515,147, 2,496,903, 4,038,075 and 4,119,462; British Patent Nos. 1,430,998 and 1,455,413; Japanese Patent Publication Open to Public Inspection (hereinafter called Japanese Patent O.P.I. Publication) Nos. 15831-1978, 62450-1980, 62451-1980, 62452-1980, 62453-1980 and 12422-1976; and Japanese Patent Publication Nos. 12422-1976 and 49728-1980. However, most compounds have displayed unsatisfactory development acceleration effects. Even compounds which displayed a satisfactory development acceleration effect have not been practically applicable as fog has often been produced. Various types of permeating agents have been studied for the purpose of accelerating the permeation of a color developing agent into a silver halide light-sensitive material. For example, a method in which benzyl alcohol is added to a color developer to accelerate color development has often been tried. However, in this method a satisfactorily high color density cannot be obtained unless processing is carried out for three minutes or longer at a processing temperature of 33°C, for example. Therefore, this method has, more or less, a fault from the viewpoint of rapid processability. A color developing method in which the pH value of a color developer as well as the processing temperature are increased has also been proposed. However, this method has drawbacks in that, for example, the oxidation of the color developing agent is considerably accelerated when the pH thereof is raised to 10.5 or higher; the pH of a color developing agent is apt to vary, because there is no suitable buffer; stable photographic characteristics are, therefore, difficult to obtain and thus the dependence on processing time may become greater. Methods in which a color developing agent is incorporated in advance into a light-sensitive material, as described in, for example, U.S. Patent No. 3,719,492 have also been tried in an attempt to improve the speed of color development. However, these methods have defects in that the raw stock stability of silver halide photographic light-sensitive materials is poor; fog is produced before the material is used; and fog is also apt to be produced in the color developing process. Besides the above methods, for the purpose of making the amine portion of the color developing agent inert, there is, for example, a method of incorporating the color developing agent which was made in the form of a Schiff base. This method is described in, for example, U.S. Patent No. 3,342,559 and Research Disclosure, 1976, No. 15159. In these methods, however, color development is not started until the alkali-hydrolysis of the color developing agent is completed, and therefore these methods have a drawback in that color development is delayed. Japanese Patent O.P.I. Publication No. 64339-1981 discloses a method of adding a 1-aryl-3-pyrazolidone having a specific structure into a silver halide color photographic light-sensitive material; and Japanese Patent O.P.I. Publication Nos. 144547-1982, 50532-1983, 50533-1983, 50534-1983, 50535-1983 and 50536-1983 each disclose the methods of adding, in advance, 1-arylpyrazolidones into a silver halide color photographic light-sensitive material and processing the light-sensitive material within a very short developing time. However, from the viewpoint of obtaining both a satisfactorily high color developing rate and a high color density dye-image, the techniques disclosed in the above-given specifications are not always satisfactory, and there is scope for improvement. In recent years, it has been found that a silver chloride emulsion or a silver chlorobromide emulsion having a high silver chloride content can be used as a silver halide emulsion to increase the speed of color development. These techniques are described in, for example, U.S. Patent Nos. 4,183,756 and 4,225,666; Japanese Patent O.P.I. Publication Nos. 26589-1980, 91444-1983, 95339-1983, 94340-1983, 95736-1983, 106538-1983, 107531-1983, 107532-1983, 107533-1983, 108533-1983 and 125612-1983. The techniques described in the above patent specifications are reasonably satisfactory from the viewpoint of rapid processability and superior to the various types of rapid processing means aforementioned. They are still not satisfactory for making sensitivity faster and, further, have drawbacks in that the sensitivity variation thereof on standing is considerable, particularly in the preparation of a light-sensitive material. When a silver halide photographic light-sensitive material is prepared, a coating liquid for a silver halide emulsion (hereinafter called a coating liquid) is ordinarily prepared so that silver halide grains which have been spectrally sensitized and chemically ripened are mixed together with various additives such as a binder, a surafce active agent, a hardener, a coupler or a mordant. It is well-known that a silver halide photographic light-sensitive material is completed by coating the coating liquid over a support in various ways and then by drying it. Upon preparation, the above-mentioned coating liquid is coated at a certain temperature after a lapse of from several hours to some tens of hours. During that period of time, the quality of the resulting silver halide photographic light-sensitive material should be stable. However, silver halide emulsions having a high silver chloride content have a serious practical limitation, because the sensitivity thereof varies considerably with the lapse in aging time of the prepared coating liquid, as compared to conventional silver halide emulsions having a high silver bromide content. In order to prevent the characteristics (particularly, sensitivity) of the above-mentioned coating liquid from varying during storage, measures have been proposed such as: a method of adding an azole, an azaindene or the like which have been well-known as stabilizers; a method of adding such a reducing agent as a hydroquinone, a sulfinic acid or the like; a method of jointly using a specific copolymer and an optical brightening agent, as described in, for example, Japanese Patent O.P.I. Publication No. 111629-1974; a method of adding a spectral sensitizing dye as described in, for example, Japanese Patent O.P.I. Publication No. 7629-1983; and a method in which a water-soluble bromide is added into a coating liquid so as to prevent a spectral sensitizing dye from desorbing in the coating liquid, as described in, for example, Japanese Patent O.P.I. Publication No. 28738-1983. None of the above-given methods may actually be effective in satisfying any characteristic requirements. JP-A-595 238 describes a mesocyanine dye for use as a silver chlorobromide particle sensitizer in a blue-sensitive emulsion with improved stability over time. It has now been unexpectedly found that when a coating liquid is prepared using a specific high silver chloride containing emulsion which is chemically ripened and a specific amount of a water-soluble bromide is then added thereto and further a coupler is dispersed therein by making use of a specific high boiling organic solvent, the resulting coating liquid may be used to prepare a silver halide photographic light-sensitive material which is high in sensitivity, has excellent rapid processability and decreased sensitivity variation to changes on standing in the course of preparing the light-sensitive material. The invention seeks to provide a silver halide photographic light-sensitive material having excellent rapid processability, high sensitivity and less sensitivity variation to changes on standing in the course of preparing the light-sensitive material. Accordingly, the invention provides a silver halide photographic light-sensitive material comprising a support bearing at least one silver halide emulsion layer thereon, wherein at least one silver halide emulsion layer comprises silver halide grains having a silver chloride content of not less than 90 mol%, a water-soluble bromide in an amount of from 0.05 mol% to 2 mol% per mol of silver halide and a coupler dispersed in a high boiling organic solvent having a dielectric constant of not higher than 6.0 (measured at 30°C), and a process for preparing a silver halide photographic light-sensitive material comprising a support bearing at least one silver halide emulsion layer thereon, comprising incorporating silver halide grains having a silver chloride content of not less than 90 mol%, into at least one of silver halide emulsion layer, incorporating a water-soluble bromide in an amount from 0.05 to 2 mol% per mol of silver halide into the emulsion layer after completion of chemical ripening of the silver halide grains, further incorporating a coupler dispersed in a high boiling organic solvent having a dielectric constant of not higher than 6.0 (measured at 30°C) into the silver halide emulsion layer. In this invention, the sensitivity variation caused by changes in the coating liquid on standing can be improved by using a silver halide emulsion containing silver halide grains with a high chloride content is, added together with a specific amount of a water-soluble bromide and a coupler dispersed in a high boiling organic solvent having a dielectric constant of not higher than 6.0, by virtue of a synergistic effect. In the invention, the word, 'water-soluble', of the above-mentioned 'water-soluble bromide' means that not less than 0.1 g of the bromide dissolves in 100 g of water at 25°C. Any bromide compound may be used, provided that it satisfies the above-mentioned requirement. Typically, salts such as ammonium bromide, potassium bromide, sodium bromide or lithium bromide may be used. The water-soluble bromides used in the invention may be added at any point of time from the completion of the chemical ripening of a silver halide emulsion to the coating of the emulsion. For example, the bromide may be added together with or separately from a compound such as a stabilizer which is to be added at completion of chemical ripening, or it may be added when the coating liquid is prepared. The latter is preferable to the former. Water-soluble bromides relating to the invention are added in an amount within the range of from 0.05 mole% to two mole% per mole of silver halide used. A better result may be obtained when they are added in an amount of 0.1 mole% to 1.5 mole% and, more preferably, from 0.15 mole% to one mole%. The high boiling organic solvents having a dielectric constant of not higher than 6.0 are added as a dispersion assistant usually for a photographic additive such as a coupler, a UV absorbent or an oxidation inhibitor. However, the organic solvents may also be added independently. The high boiling organic solvents having a dielectric constant of not higher than 6.0 include, for example, esters such as a phthalate or a phosphate, organic acid amides, ketones or hydrocarbon compounds, each having a dielectric constant of not higher than 6.0. Preferable high boiling organic solvents have a dielectric constant not higher than 6.0 and not lower than 1.9 and a vapor pressure of not higher than 0.5 mmHg at 100°C. The more preferable solvents are phthalates or phosphates. The organic solvent may be a mixture of two or more such solvents, provided that the dielectric constant of the mixture is not higher than 6.0. In the invention, the dielectric constant values are those obtained at 30°C. The phthalates advantageously used in the invention include those represented by Formula HA; wherein R H1 and R H2 each independently represent alkyl, alkenyl or aryl, provided that the total number of carbon atoms is the groups represented by R H1 and R H2 , taken together, is from 9 to 32 and, more preferably, from 16 to 24. In Formula HA, the alkyl groups represented by R H1 and R H2 are straight-chained or branched, including, for example, butyl, hexyl, octyl, nonyl, dodecyl, tetradecyl, hexadecyl, heptadecyl and octadecyl group. The aryl groups represented by R H1 and R H2 include, for example, phenyl and naphthyl, and the alkenyl groups include, for example, hexenyl, heptenyl and octadecenyl. These alkyl, alkenyl and aryl groups may have at least one substituent. In the above-given formula, R H1 and R H2 preferably represent alkyl including, for example, 2-ethylhexyl, 3,5,5-trimethylhexyl, n-octyl and n-nonyl. Suitable phosphates include these represented by Formula HB; wherein R H3 , R H4 and R H5Y each independently represent alkyl, alkenyl or aryl, respectively, provided that the total number of carbon atoms in the groups represented by R H3 , R H4 and R H5 , taken together, is from 24 to 54. In Formula HB, the alkyl groups represented by R H3 , R H4 and R H5 are straight-chained or branched, including, for example, butyl, pentyl, hexyl, octyl, nonyl, dodecyl, pentadecyl, hexadecyl, octadecyl and nonadecyl. These alkyl groups, alkenyl groups and aryl groups may have at least one substituent. The preferable alkyl groups represented by R H3 , R H4 and R H5 include, for example, 2-ethylhexyl, n-octyl, 3,5,5-trimethylhexyl, n-nonyl, n-decyl, sec-decyl, sec-dodecyl and t-octyl. Typical examples of the organic solvents relating to the invention are given below. The high boiling organic solvents may be used in an amount within the range of from 0.01 mole to 10 moles per mole of silver halide used and, more preferably, from 0.05 mole to 5 moles. The amount of high boiling organic solvent added to a coupler is preferably from 25 to 150% by weight to the coupler and, more preferably, from 50 to 100% by weight. In the silver halide photographic light-sensitive materials of the invention, silver halide grains are contained in at least one silver halide emulsion layer in order to achieve rapid processability. The silver halide grains have a silver chloride content of not less than 90 mole%. The silver chloride content preferable for the effects of the invention is not less than 95 mole% and, more preferably, not less than 99.0 mole%. The silver halide grains may be silver chlorobromide, silver iodochloride, silver chloroiodobromide or silver chloride; while they may contain silver iodide, the content thereof is preferably not more than one mole% and, more preferably, not more than 0.5 mole%. It is most preferable that no silver iodide should be present. The most suitable silver halide grains are silver chlorobromide and silver chloride. The silver halide grains relating to the invention may be mixed with silver halide grains other than those of the invention. In this case, however, in a silver halide emulsion layer containing the silver halide grains relating to the invention, the ratio of the projective area occupied by the silver halide grains of the invention to the projective area occupied by the total number of silver halide grains contained in the emulsion layer is preferably not less than 50% and more preferably not less than 75%. The silver halide grains of the invention can be prepared in accordance with the methods described in, for example, Japanese Patent O.P.I. Publication Nos. 162540-1984, 48755-1984, 222844-1985, 222845-1985 and 136735-1985. There is no special limitation to the sizes of the silver halide grains used in the invention. However, taking rapid processability, sensitivity and other photographic characteristics into consideration, the grain sizes are preferably within the range of from 0.2 to 1.6µm and more preferably from 0.25 to 1.2µm. The above-mentioned grain sizes may be measured by various methods which have conventionally been used in the art. Typical methods are described in R.P. Loveland, 'Particle-Size Measurement', ASTM Symposium on Light Microscopy, 1955, pp. 94-122; or C.E.K. Mees and T.H. James, 'The Theory of the Photographic Process', 3rd Ed., Chapter 2, The Macmillan Co., 1966. The above-mentioned grain sizes may be measured in terms of the projective area of grains or the approximate value of grain diameter. When grains are substantially uniform in shape, the grain size distribution may be fairly accurately expressed in terms of either a diameter or projective area. The distribution of grain sizes of the silver halide grains may be either polydispersed or monodispersed. Preferably, grains are monodispersed having a variation coefficient of preferably not more than 0.22 and more preferably not more than 0.15. Herein, a variation coefficient means the coefficient indicating the broadness of grain size distribution and is defined by the following equations; wherein ri represents a grain size of individual grains and ni is the number thereof. The term 'grain size' stated herein means the diameter of silver halide grains when they are in the globular form or, when such grains are in the cubic form or the other forms than the cubic form, the diameter of the circular image having the same areas as the projective image areas of the grains. The silver halide grains relating to the invention may be prepared by, e.g., an acidic process, a neutral process or an ammoniacal process. These grains may be grown either directly or after preparation of seed grains. Methods of preparing seed grains and methods of growing grains may be the same or different. Methods of reacting a soluble silver salt with a soluble halide include normal precipitation methods, reverse precipitation methods and double-jet precipitation methods and combinations thereof. Among the grains, those prepared in double-jet precipitation methods are preferred. A pAg-controlled double-jet method may be used as a double-jet precipitation method, as described in, for example, Japanese Patent O.P.I. Publication No. 48521-1979. If further required, silver halide solvents may be used such as thioether or crystal-habit controllers such as a mercapto group-containing compounds and spectral sensitizing dyes. Silver halide grains having any configurations may be used. A preferable example is grains in the form of a cube having a {100} crystal face. Besides the above, grains having a form such as an octahedron, tetradecahedron or dodecahedron may be used, as prepared in the methods described in, for example, U.S. Patent Nos. 4,183,756 and 4,225,666; Japanese Patent O.P.I. Publication No. 26589-1980; Japanese Patent Publication No. 42737-1980; and The Journal of Photographic Science, 21 , p. 39, (1973). Grains having twin-crystal faces or irregular forms may also be used. Silver halide grains used in relation to the invention may either have a single form or various forms. However, grains of a single form are rather preferable. In the course of forming and/or growing the silver halide grains relating to the invention, metal ions are generally added into the grains; these may be cadmium salts, zinc salts, lead salts, thalium salts, iridium salts or complexes thereof, rhodium salts or complexes thereof, iron salts or complexes thereof, so that the metal ions are contained inside the grains and/or in the surfaces thereof. In addition, a reduction sensitization nucleus may be provided inside the grains and/or to the surfaces thereof by putting the grains in a suitably reducting atmosphere. Unnecessary soluble salts may be removed from the emulsions of the invention after completing the growth of silver halide grains, or may be contained as they are. If the salts are removed, this may be carried out according to the method described in, for example Research Disclosure, No. 17643. The silver halide grains relating to the invention may be capable of forming a latent image mainly either inside or on the surface thereof. Preferable grains are those capable of forming a latent image mainly on the surface thereof. The silver halide emulsions used in the invention may be chemically sensitized in accordance with conventional methods. Suitable methods include a gold sensitizing method using gold complex salts, a reduction sensitizing method using a reducible substance, a sulfur sensitizing method using a compound containing sulfur capable of reacting with silver ions or using the so-called active gelatin or a method using a noble metal salt belonging to the VIII Group of the Periodic Table. In particular, it is preferable that the silver halide emulsion layer of the invention contains a gold sensitizer. Suitable gold compounds include, for example, chloroauric acid, sodium chloroaurate and auric potassium thiosulfate. The amount of gold compound added is generally from 5x10⁻⁷ to 5x10⁻³ mole per mole of silver halide used, preferably from 2x10⁻⁶ to 1x10⁻⁴ mole, more preferably from 2.6x10⁻⁶ to 4x10⁻⁵ mole, and most preferably from 2.6x10⁻⁶ to 9x10⁻⁶ mole per mole of the silver halide used. The gold compound may be added at any stage during the preparation of the silver halide emulsion. It is, however, preferably added between completion of silver halide formation and completion of chemical sensitization. The gold compound may also be added into the silver halide emulsion before the emulsion is coated, upon completion of chemical sensitization and after adding a compound known as an antifoggant or a stabilizer in the photographic industry. Addition of the gold compound may be made at a time when a sensitization effect may be derived, but also at any time other than the above. It is preferred that the silver halide emulsion layers of the invention contain a sulfur sensitizer. Suitable sulfur sensitizers include, for example, sodium thiosulfate or a thiourea derivative such as diphenyl thiourea and allyl thiourea. A sulfur sensitizer may be added in an amount sufficient to sensitize silver halides and no special limitations apply. However, as a rough standard, sodium thiosulfate, for example, may be added in an amount of preferably from 1x10⁻⁷ to 1x10⁻⁵ and more preferably from 2x10⁻⁶ to 8x10⁻⁶ mole, per mole of silver halide used. In order to prevent sensitivity lowering and fog occurrence during storing or processing of the light-sensitive material, a variety of compounds may be added into the silver halide emulsions as mentioned above. As for these compounds, there are a variety of known heterocyclic compounds and mercapto compounds including 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene, 3-methylbenzothiazole, 1-phenyl-5-mercaptotetrazole. In particular, mercapto compounds which may advantageously be used in the invention are of Formula S; wherein Q represents a group of atoms which completes a 5- or 6-membered heterocyclic ring or a 5- or 6-membered heterocyclic ring condensed with a benzene ring; and M represents hydrogen or a cation. Mercapto compounds or Formula S will be described below. In Formula S, Q represents a group of atoms which completes a 5- or 6-membered heterocyclic ring or a 5- or 6-membered heterocyclic ring condensed with a benzene ring. The heterocyclic rings completed by Q include, for example, an imidazole ring, a tetrazole ring, a thiazole ring, an oxazole ring, a selenazole ring, a benzoimidazole ring, a naphthoimidazole ring, a benzothiazole ring, a naphthothiaazole ring, a benzoselenazole ring, a naphthoselenazole ring and a benzoxazole ring. The cations represented by M include, for example, alkali metals such as sodium or potassium; or an ammonium group. The mercapto compounds of Formula S include, preferably, those represented by the following Formulae SA, SB, SC and SD, respectively; wherein R A represents hydrogen, alkyl, alkoxy, aryl, halogen, carboxyl or salts thereof, sulfo or salts thereof, or amino; Z represents -NH-, -O- or -S-; and M is as defined for M in Formula S above. wherein Ar represents R B represents alkyl, alkoxy, carboxyl or salts thereof, sulfo or salts thereof, hydroxyl, amino, acylamino, carbamoyl or sulfonamido; n is 0, 1 or 2; and M is as defined for M in Formula S above. In Formulae SA and SB, the alkyl groups represented by R A and R B include, for example, methyl, ethyl and butyl; alkoxy includes, for example, methoxy and ethoxy; and salts of the carboxyl or sulfo groups include, for example, a sodium salt and an ammonium salt. In Formula SA, the aryl groups represented by R A include, for example, phenyl and naphthyl; and halogen includes, for example, chlorine and bromine. In Formula SB, the acylamino groups represented by R B include, for example, methylcarbonylamino and benzoylamino; carbamoyl includes, for example, ethylcarbamoyl and phenylcarbamoyl; and sulfonamido includes, for example, methylsulfonamido and phenylsulfonamido. The above-mentioned alkyl, alkoxy, aryl, amino, acylamino, carbamoyl, sulfonamido and the like groups include those having further substituents. wherein Z represents oxygen or sulfur; R A represents hydrogen, alkyl, aryl, alkenyl, cycloalkyl, -SR A1 , -NHCOR A4 , -NHSO₂R A5 , or a heterocyclic group; R A1 represents hydrogen, alkyl, alkenyl, cycloalkyl, aryl, -COR A4 or -SO₂R A5 ; R A2 and R A3 independently represent hydrogen, alkyl, or aryl; R A4 and R A5 independently represents alkyl or aryl; and M is as defined for M in Formula S above. Alkyl groups represented by R A , R A1 , R A2 , R A3 , R A4 and R A5 in Formula SC include, for example, methyl, ethyl and propyl; and the aryl groups include, for example, phenyl, benzyl or naphthyl. Alkenyl groups represented by R A and R A1 include, for example, propenyl; the cycloalkyl groups include, for example, cyclohexyl. Heterocyclic groups represented by R A include, for example, furyl and pyridinyl. The above-given alkyl and aryl groups represented by R A , R A1 , R A2 , R A3 , R A4 and R A5 ; the alkenyl and cycloalkyl groups represented by R A and R A1 ; and the heterocyclic groups represented by R A ; each further includes those having substituents. wherein R A and M each are as defined for R A and M in Formula SC; and R B1 and R B2 each are as defined for R A1 and R A2 in Formula SC. Typical examples of the compounds represented by Formula S are shown below. Compounds of Formula S may include the compounds described in, for example, Japanese Patent Publication No. 28496-1965; Japanese Patent O.P.I. Publication No. 89034-1975; Journal of Chemical Society, 49, 1748 (1927) and 4237 (1952); Journal of Organic Chemistry, 39, 2469 (1965); U.S. Patent No. 2,824,001; Journal of Chemical Society, 1723 (1951); Japanese Patent O.P.I. Publication No. 111846-1981; British Patent No. 1,275,701; and U.S. Patent Nos. 3,266,897 and 2,403,927. These compounds may be synthesized according to methods described in the above-given literature. Compounds of Formula S (hereinafter called Compounds S) may be contained in the silver halide emulsion layer containing silver halide grains, in such a manner that the Compound S is dissolved in water or an organic solvent such as methanol or ethanol which is capable of being freely mixed with water. Compounds S may be used independently, jointly with two or more compounds of formula S, or in combination with a stabilizer or an antifoggant other than compounds of Formula S. Compound S is usually added when the chemical sensitization of the silver halide is completed, and may also be added after silver halide grains are formed or when starting or during chemical sensitization. It is, however, preferable that Compounds S should be added in stages when starting and completing chemical sensitization. The amount of compound S to be added is not especially limitative. However, it is usually within the range of from 1x10⁻⁶ mole to 1x10⁻¹ mole and preferably from 1x10⁻⁵ mole to 1x10⁻² mole per mole of silver halides used. The emulsions relating to the invention may be spectrally sensitized to a desired wavelength region by making use of a dye which is known as a spectral sensitizing dye in the photographic industry. Such a spectral sensitizing dye may be used independently or two or more in combination. The emulsion may also contain a dye not having any spectral sensitizing function itself or a compound which does not substantially absorb any visible rays of light, i.e., a supersensitizer capable of enhancing the sensitizing function of a spectral sensitizing dye, as well as the spectral sensitizing dye. When using the silver halide emulsion relating to the invention as a blue-sensitive emulsion, it is preferred that such an emulsion should be spectrally sensitized with a spectral sensitizing dye of Formula A; In Formula A, Z₁₁ and Z₁₂ independently represent a group of atoms which completes a benzoxazole nucleus, a naphthoxazole nucleus, a benzoselenazole nucleus, a napthoselenazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzoimidazole nucleus, a naphthoimidazole nucleus, a pyridine nucleus or a quinoline nucleus, and these heterocyclic rings include those having substituents. The substituents of the heterocyclic rings completed by Z₁₁ and Z₁₂ include, for example, halogen, cyano, methyl, ethyl, methoxy or ethoxy. R₂₁ and R₂₂ each, independently, represent alkyl, alkenyl or aryl, preferably alkyl and preferably alkyl substituted by carboxyl or sulfo, and most preferably one sulfoalkyl having 1 to 4 carbon atoms. R₂₃ represents hydrogen, methyl or ethyl. X ⊖ represents an anion and ℓ is 0 or 1. Among the spectral sensitizing dyes of Formula A, the particularly useful dyes are of Formula A'; wherein Y₁ and Y₂ each, independently, represent a group of atoms which completes a substitutable benzene or naphthalene ring. The benzene or naphthalene ring completed by Y₁ and Y₂ may be substituted. Suitable substituents include, preferably, halogen, cyano, methyl, ethyl, methoxy or ethoxy. R₂₁, R₂₂, R₂₃, X ⊖ and ℓ are as defined in Formula A above, respectively. Typical examples of the spectral sensitizing dyes represented by Formula A which may be used in the invention are given below. When using a green-sensitive emulsion as a silver halide emulsion, it is preferred to use spectral sensitizing dyes of Formula B; wherein Z₁₁ and Z₁₂ each, independently, represent a group of atoms which completes a benzene or naphthalene ring each condensed with an oxazole ring. Thus completed heterocyclic ring nuclei may be substituted by a variety of substituents which include, for example, halogen, aryl, alkyl and alkoxy. More preferable substituents include halogen, phenyl and methoxy. The most preferable substituent is phenyl. Typically, Z₁₁ and Z₁₂ each, independently, represent a benzene ring condensed with an oxazole ring and at least one of these benzene rings is substituted with a phenyl group at the 5-position, or one benzene ring is substituted by phenyl at the 5-position and the other benzene ring is substituted by halogen at the 5-position. R₂₁ and R₂₂ each, independently, represent alkyl, alkenyl or aryl; preferably alkyl, more preferably alkyl substituted by carboxyl or sulfo, most preferably sulfoalkyl having 1 to 4 carbon atoms and further most preferably a sulfoethyl. R₂₃ represents hydrogen or alkyl having 1 to 3 carbon atoms and preferably hydrogen or ethyl. X₁ ⊖ represents an anion such as a halide, for example chloride, bromide or iodide; and an anion of CH₃SO₄ or C₂H₅SO₄; n is one or zero, and n is 0 when the compound forms an intramolecular salt. Typical examples of the spectral sensitizing dyes represented by Formula B, which may preferably be used in the invention, are given below. When using a red-sensitive emulsion as the silver halide emulsion, it is preferred to use spectral sensitizing dyes of Formulae C or D, respectively; wherein R represents hydrogen or alkyl; R₁ to R₄ each, independently, represent alkyl or aryl; Z₁, Z₂, Z₄ and Z₅ each, independently, represent a group of atoms which completes a benzene or naphthalene ring condensed with a thiazole or selenazole ring; Z₃ represents a group of hydrocarbon atoms which completes a 6-membered ring; ℓ is one or two; Z represents sulfur or selenium; and X ⊖ represents an anion. In the above-given Formula, alkyl groups represented by R include, for example, methyl, ethyl and propyl; and R is preferably hydrogen, methyl or ethyl and, more preferably, hydrogen or ethyl. R₁, R₂, R₃ and R₄ each, independently, represent an optionally substituted straight-chained or branched alkyl group, such as methyl, ethyl, propyl, chloroethyl, hydroxyethyl, methoxyethyl, acetoxyethyl, carboxymethyl, carboxyethyl, ethoxycarbonylmethyl, sulfoethyl, sulfopropyl, sulfobutyl, β-hydroxy-γ-sulfopropyl, sulfate-propyl, allyl or benzyl; or an optionally substituted aryl group, such as phenyl, carboxyphenyl or sulfophenyl. The heterocyclic rings completed by Z₁, Z₂, Z₄ and Z₅ may be substituted by, for example, halogen, aryl, alkyl or alkoxy and, more preferably, halogen such as chlorine, phenyl and methoxy group. X ⊖ represents an anion such as Cl, Br, I, CH₃SO₄ or C₂H₅SO₄; and ℓ is 1 or 2. Typical examples of spectral sensitizing dyes which may be used in the invention, represented by Formulas C and D, are shown below. The amount of the spectral sensitising dyes represented by the above-given Formula A, B, C or D added is not specially limited, but is generally within the range of preferably about 1x10⁻⁷ to 1x10⁻³ mole and, more preferably 5x10⁻⁶ to 5x10⁻⁴ mole, per mole of silver halide used. Any conventional method known in the art may be used to add the spectral sensitizing dyes. For example, the spectral sensitizing dyes may be added by being dissolved in a water-soluble solvent such as pyridine, methyl alcohol, ethyl alcohol, methyl cellosolve or acetone or mixtures thereof, they may be diluted or dissolved with water, so that they may be added in the form of a solution. In addition, a supersonic oscillation may advantageously be used during dissolution. When adding the sensitizing dyes to be used in the invention, a method as described in, for example, U.S. Patent No. 3,469,987 may be applied, in which the dye is dissolved in a volatile organic solvent and the resultant solution is dispersed in a hydrophilic colloid and the resulted dispersion is then added; or such a method as described in, for example, Japanese Patent Publication No. 24185-1971 in which a water-insoluble dye is dispersed without being dissolved in a water-soluble solvent and the resultant dispersion is then added. The sensitizing dyes which may be used in the invention may be added in the form of a dispersion into an emulsion in an acidic dissolution-dispersion method. As a method of adding the sensitizing dyes the methods described in, for example, U.S. Patent Nos. 2,912,345, 3,342,605, 2,996,287 and 3,425,835 may be used. The sensitizing dyes which are to be contained in a silver halide emulsion of the invention may be added in such a manner that they are dissolved in the same or different solvents and the resultant solutions are mixed up together before addition into the silver halide emulsion, or they may be added separately. When adding them separately, the order of addition, time of addition and intervals of addition may be freely determined according to the purposes of use. The sensitizing dyes may be added into an emulsion at any point during the course of preparation of the emulsion; however, preferably, addition occurs during or after chemical ripening and, more preferably, during chemical ripening.For the purpose of further improving the effects of the invention, it is preferable to add the sensitizing dyes at intervals during chemical ripening and in a coating liquid. The silver halide photographic light-sensitive materials of the invention may be in the form of, for example, a color negative or positive film, or a color print paper. The effects of the invention are particularly apparent when using a color print paper. The silver halide photographic light-sensitive materials including the above-mentioned color print paper may be either monochromic or multicolor. Multicolor silver halide photographic light-sensitive materials, usually have a constitution such that silver halide emulsion layers containing respectively magenta, yellow and cyan couplers each for photographic couplers and non-sensitive layers coated with an appropriate number and arrangement of layers onto a support, so as to perform color reproduction in a subtractive color process. The number and coating order of the layers may suitably be altered according to the desired characteristics and purposes of the light-sensitive materials to be prepared. When the silver halide photographic light-sensitive material is a multicolor light-sensitive material, a particularly preferable layer arrangement is as follows: on and from a support in order, a yellow dye image forming layer, an interlayer, a magenta dye image forming layer, an interlayer, a cyan dye image forming layer, an interlayer, and a protective layer. There is no special limitation to the dye image forming couplers applicable to the invention, and there are a variety of couplers available to be used. Suitable examples include the compounds described in the following patents. Yellow dye image forming couplers include four-equivalent or two-equivalent acylacetamide or benzoylmethane couplers. These couplers are described in, for example, U.S. Patent Nos. 2,778,658, 2,875,057, 2,908,573, 2,908,513, 3,227,155, 3,227,550, 3,253,924, 3,265,506, 3,277,155, 3,341,331, 3,369,895, 3,384,657, 3,408,194, 3,415,652, 3,447,928, 3,551,155, 3,582,322 and 3,725,072; West German Patent Nos. 1,547,868, 2,057,941, 2,162,899, 2,163,812, 2,213,461, 2,219,917, 2,261,361 and 2,263,875; Japanese Patent Publication No. 13576-1974; and Japanese Patent O.P.I. Publication Nos. 29432-1973, 66834-1973, 10736-1974, 122335-1974, 28834-1975, 132926-1975, 144240-1980 and 87041-1981. Magenta dye image forming couplers include tetramer or dimer magenta dye image forming couplers of the 5-pyrazolone type, pyrazolotriazole type, pyrazolinobenzimidazole type, indazolone type and cyanoacetyl type. These are described in, for example, U.S. Patent Nos. 2,600,788, 3,061,432, 3,062,653, 3,127,269, 3,311,476, 3,152,896, 3,419,391, 3,519,429, 3,555,318, 3,684,514, 3,705,896, 3,888,680, 3,907,571, 3,928,044, 3,930,861, 3,930,816, and 3,933,500; Japanese Patent O.P.I. Publication Nos. 29639-1974, 111631-1974, 129538-1974, 112341-1976, 58922-1977, 62454-1977, 118034-1977, 38643-1981 and 135841-1981; Japanese Patent Publication Nos. 60479-1971, 34937-1977, 29421-1980 and 35696-1980; British Patent No. 1,247,493; Belgian Patent Nos. 769,116; West German Patent No. 2,156,111; Japanese Patent Publication No. 60479-1971; Japanese Patent O.P.I. Publication Nos. 125732-1984, 228252-1984, 162548-1984, 171956-1984, 33552-1985 and 43659-1985; West German Patent No. 1,070,030; and U.S. Patent No. 3,725,067. Cyan dye image forming couplers include, typically four-equivalent or two-equivalent cyan dye image forming couplers of the phenol type and the napthol type. They are described in, for example, 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, 2,985,826, 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; British Patent Nos. 478,991, 945,542, 1,084,480, 1,377,233, 1,388,024 and 1,543,040; and Japanese Patent O.P.I. Publication Nos. 37425-1972, 10135-1975, 25228-1975, 112038-1975, 117422-1975, 130441-1975, 6551-1976, 37647-1976, 52828-1976, 108841-1976, 109630-1978, 48237-1979, 66129-1979, 131931-1979, 32071-1980, 146050-1984, 31953-1984 and 117249-1985. It is desired that the above-mentioned dye forming couplers contain in their molecules a so-called ballast group which is a group having not less than eight carbon atoms such that the coupler is not capable dispersing into another layer. These dye forming couplers may be either of the four-equivalent type which require four silver ions to form one molecule of dye, or those of the two-equivalent type which require two silver ions. Suitable binders include gelatin or a protective colloid; hydrophilic colloids may also be used including, for example gelatin derivatives, graft polymers of gelatin and other macromolecules, proteins, sugar derivatives, cellulose derivatives, and synthetic hydrophilic macromolecular substances such as monomers or copolymers. The silver halide photographic light-sensitive materials of the invention may also contain additives such as hardeners, color contamination inhibitors, image stabilizers, UV absorbers, plasticizers, a latexes, surfactants, matting agents, lubricants, and antistatic agents. Images may be formed from silver halide photographic light-sensitive materials of the invention by conventional color development processes. The color developing agents applicable to the color developers used in the invention include those of the aminophenol type and p-phenylenediamine type, each of which have been widely used in a variety of color photographic processes. The color developers applicable for processing the silver halide photographic light-sensitive materials of the invention may be added together with compounds already known as developer components, in addition to the above-mentioned aromatic primary amine type color developing agents. It is, however, more preferable not to use benzyl alcohol which causes environmental pollution problems. The pH value of such color developers is normally not less than 7 and most generally from about 10 to 13. The processing temperature of suitable color developers is normally not lower than 15°C and generally within the range of from 20 to 50°C. For rapid processing, a temperature of 30°C or higher would be preferable. While the conventional processing time is from 3 to 4 minutes, a color processing time used in the invention with the purpose of rapidly processing is generally within the range of preferably from 20 to 60 seconds and more preferably from 30 to 50 seconds. After color develoment is complete, the silver halide photographic light-sensitive materials of the invention are then treated in a bleaching process and a fixing process. Such bleaching and fixing processes may be carried out at the same time. After the fixing process, a washing process is normally carried out. The washing process may be substituted by a stabilizing process, or both processes may be carried out in combination. As described above, the silver halide photographic light-sensitive materials of the invention were rapidly processable, had high sensitivity and less sensitivity variation to the change on standing in the course of preparing the light-sensitive materials. EXAMPLES The following Examples illustrate the invention. Example-1 A monodispersed silver chlorobromide emulsion having a silver chloride content of 99.5 mole% was prepared, according to the method described in Japanese Patent O.P.I. Publication No. 48521-1979, in such a manner that, in the presence of inert gelatin and under the conditions of a temperature of 40°C, a pAg of 6.8 and a pH of 2.0, an aqueous silver nitrate solution and an aqueous solution of potassium bromide and sodium chloride were added and mixed. In an electron microscopic observation it was found that the resultant silver halide emulsion contained cubic grains having an average grain size of 0.15 µm in terms of sphericity. Next, a phthalated gelatin was added to the silver halide emulsion and the pH was lowered with nitric acid and precipitation of silver halide grains occurred. The resulting supernatant liquid was removed. The remaining matter was washed with water repeatedly and the pAg thereof was adjusted to 7.5. Additional inert gelatin was added so as to prepare a seed emulsion. Another monodispersed silver chlorobromide emulsion having a silver chloride content of 99.6 mole% was prepared in such a manner that, under the conditions of a temperature of 40°C, a pH of 5.8 and a pAg of 7.5, a mixed solution of a part of the above-mentioned seed emulsion and gelatin was added and mixed up with an aqueous silver nitrate solution and an aqueous solution of potassium bromide and sodium chloride in an amount so as not to produce any new nuclei. The resulting silver halide emulsion comprised cubic grains having an average grain size of 0.80 µm. In the course of mixing, these grains were added with Na₂IrCℓ₆.6H₂O in an amount of 3x10⁻⁷ mole per mole of AgX. Further, after the silver halide emulsion was flocculated and washed using conventional methods, the pAg was adjusted and an additional gelating was added. Still further, sodium thiosulfate in an amount of 3.5x10⁻⁶ mole per mole of AgX, chloroauric acid in an amount of 2.7x10⁻⁶ mole per mole of AgX, a blue-sensitive sensitizing dye, i.e., Exemplification No. A-12, in an amount of 3x10⁻⁴ mole per mole of AgX and an exemplified mercapto compound, i.e., SB-5, in an amount of 1x10⁻³ mole per mole of AgX were added at 55°C before starting the chemical sensitization process. The resulting mixture was spectrally sensitized and chemically sensitized, and the exemplified mercapto compound, SB-2, was added in an amount of 1x10⁻² mole per mole of AgX to serve as a stabilizer when the ripening process had been completed, so that a ripened emulsion was prepared. Next, dispersions were prepared in such a manner that the yellow coupler Y-1 was dispersed respectively with the exemplified high boiling organic solvents having dielectric constants shown in Table-1, namely, H-2, H-6 and H-16, dibutyl phthalate (DBP) and tricresyl phosphate (TCP), and the coating liquids were prepared by mixing the resulting dispersions with the foregoing silver halide emulsions. In the above-mentioned preparation, potassium bromide was added to the resulted coating liquids as shown in Table-2. Then, after the coating liquids were prepared so as to have the composition shown below, the samples were prepared by coating the coating liquids over the supports, immediately after the preparation of the coating liquids, three and six hours after allowing the coating liquids to stand, respectively. Sample No. Amt. of potassium bromide added (Mol%/AgX mol) High boiling organic solvent Remark 1 - H-2 Comparison 2 0.02 H-2 Comparison 3 0.06 H-2 Invention 4 0.1 H-2 Invention 5 0.5 H-2 Invention 6 1.0 H-2 Invention 7 3.0 H-2 Comparison 8 0.5 DBP Comparison 9 1.0 DBP Comparison 10 0.5 TCP Comparison 11 1.0 TCP Comparison 12 - H-6 Comparison 13 0.5 H-6 Invention 14 1.0 H-6 Invention 15 - H-12 Comparison 16 0.5 H-12 Invention 17 1.0 H-12 Invention When preparing the coating liquids used in Sample Nos. 15, 16 and 17, the blue-sensitive sensitizing dye, i.e., Exemplification No. A-12, which was used in the spectral sensitization, was further added in an amount of 7.5x10⁻³ mole per mole of AgX. Next, with respect to each of Samples-1 through-17, sensitometric evaluation was carried out according to the following method. [Sensotometric evaluation] Each of the samples was exposed to light through an optical wedge by means of a sensitometer, Model KS-7 manufactured by Konishiroku Photo Industry Co., Ltd. and was then treated in the following processing steps. [Processing steps] Temperature Time Color developing 34.7 ± 0.3°C 45 sec. Bleach-fixing 34.7 ± 0.5°C 45 sec. Stabilizing 30 to 34°C 90 sec. Drying 60 to 80°C 60 sec. (Color developer) Pure water 800 ml. Ethylene glycol 10 ml. N,N-diethylhydroxylamine 10 g Potassium chloride 2 g N-ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-aminoaniline sulfate 5 g Sodium tetrapolyphosphate 2 g Potassium carbonate 30 g Optical brightening agent (a 4,4'-diaminostilbene disulfonic acid derivative) 1 g Water to be added to make 1 liter pH adjusted to pH10.08 (Bleach-fixer) Ferric ammonium ethylenediamine tetraacetate, dihydrate 60 g Ethylenediaminetetraacetic acid 3 g Ammonium thiosulfate (a 70% solution) 100 ml Ammonium sulfite (a 40% solution) 27.5 ml pH adjusted with potassium carbonate or glacial acetic acid to pH7.1 Water to be added to make in total 1 liter (Stabilizer) 5-chloro-2-methyl-4-isothiazoline-3-one 1 g 1-hydroxyethylidene-1,1-diphosphoric acid 2 g Water to be added to make 1 liter pH adjusted with sulfuric acid or potassium hydroxide to pH7.0 The blue reflection densities of the resulting samples were measured by making use of a densitometer, Model PDA-65 manufactured by Konishiroku Photo Industry Co., Ltd. The sensitivity of each of the samples was expressed by the reciprocal of an exposure necessary to obtain a density of 0.8. Sample-1 was used as a standard and the immediately coated sample out of the respective samples was taken as standard, the sensitivities thereof being regarded as 100, and the sensitivities of other samples were expressed as the relative values to 100. The results thereof are shown in Table-3. Sample No. Relative sensitivity Relative sensitivity to immediately coated sample regarded as 100 Immediately coated Aged for 3 hours Aged for 6 hours 1 Comp. 100 100 82 71 2 Comp. 100 100 84 73 3 Inv. 108 100 96 93 4 Inv. 116 100 98 95 5 Inv. 127 100 97 96 6 Inv. 134 100 98 97 7 Comp. 138 100 90 84 8 Comp. 119 100 83 75 9 Comp. 125 100 86 79 10 Comp. 114 100 80 70 11 Comp. 120 100 82 72 12 Comp. 101 100 79 71 13 Inv. 120 100 98 96 14 Inv. 129 100 98 97 15 Comp. 98 100 83 75 16 Inv. 138 100 101 100 17 Inv. 145 100 99 99 As is obvious from the above Table-3, in the comparative samples. i.e., Sample Nos. 1, 2, 12 and 15, in which water-soluble bromides relating to the invention were either not added at all or not in sufficient quantities, the sensitivity of each sample was relatively low and the desensitization thereof was noticeable when the coating liquids were allowed to stand. Further, even if the water-soluble bromides relating to the invention were added in sufficient quantities into the comparative samples, i.e., Sample Nos. 8 through No. 11, each of which were applied with a high boiling organic solvent other than those of the invention and provided with a relatively high dielectric constant, the desensitization thereof was noticeable when the coating liquids were allowed to stand, although the sensitivity of each of the samples immediately coated was relatively high. In contrast to the above, it was found that samples prepared in accordance with the invention are capable of displaying high sensitivity and, even if the coating liquids were allowed to stand for a long time, they still have constant and stable sensitivity. In addition to the above, it was also found that Samples No. 16 and No. 17 each coated with a sensitizing dye-containing coating liquid produce exceptional results. Example-2 In the same manner as in Example-1, a monodispersed cubic-crystallized emulsion having a silver chloride content of 99.3 moles and an average grains size of 0.35 µm was prepared. The emulsion was chemically sensitized with sodium thiosulfate in an amount of 1x10⁻⁵ mole per mole of AgX, chloroauric acid of 5x10⁻⁶ mole per mole of AgX, the exemplified mercapto compound, i.e., SB-5, in an amount of 5x10⁻³ mole per mole of AgX, the exemplified green-sensitive sensitizing dye, B-5 and, after completion of chemical sensitization, the exemplified mercapto compound, SB-1, was added in an amount of 1x10⁻² mole per mole of AgX, so that a ripened emulsion was prepared. By making use of the resulted ripened emulsion and in the same manner as in Example-1, the water-soluble bromides shown in Table-4 were mixed in a dispersion in which the following magenta coupler, M-1, was dispersed with the exemplified high boiling organic solvents, H-2, H-7 of which the dielectric constant is shown below, and DBP, so that the coating liquids shown in Table-4 were prepared. The tests for the changes of the coating liquids on standing were carried out in the same manner as in Example-1, respectively. The results thereof are shown in Table-5. Sample No. Amt. of potassium bromide added (Mole%/AgX mole) High boiling organic solvent Remark 18 - H-2 Comparison 19 0.4 H-2 Invention 20 0.8 H-2 Invention 21 1.2 H-2 Invention 22 - DBP Comparison 23 0.4 DBP Comparison 24 0.8 DBP Comparison 25 1.2 DBP Comparison 26 - H-7 Comparison 27 0.4 H-7 Invention 28 0.8 H-7 Invention 29 1.2 H-7 Invention 30 0.8 (Provided, Mercapto compound SB-1 was added at the same time) H-7 Invention Sample No. Relative sensitivity Relative sensitivity to immediately coated sample regarded as 100 Immediately coated Aged for 3 hours Aged for 6 hours 18 Comp. 100 100 86 80 19 Inv. 100 100 97 95 20 Inv. 118 100 101 98 21 Inv. 123 100 99 97 22 Comp. 98 100 82 71 23 Comp. 105 100 87 76 24 Comp. 113 100 86 79 25 Comp. 119 100 85 76 26 Comp. 101 100 86 82 27 Inv. 109 100 98 97 28 Inv. 117 100 99 97 29 Inv. 125 100 102 99 30 Inv. 112 100 98 96 It was found from the above table that Sample Nos. 19, 20, 21, 27, 28, 29 and 30 had a high sensitivity and particular aging stability. In contrast to the above, it was found that Sample Nos. 18, 22 and 26 not containing any potassium bromide in the coating liquids thereof were relatively low in sensitivity and inferior in aging stability, and that Sample Nos. 23, 24 and 25 in which high boiling solvents other than those used in the invention were inferior in aging stability, although they had relatively high sensitivity. It was also found that Sample No. 30 into which potassium bromide was added together with the mercapto compound SB-1 at the time when the chemical sensitization was completed had improved aging stability to sensitivity although the gradation was softened and the photographic characteristics thereof were also somewhat inferior to the other samples of the invention. Example-3 A silver halide color photographic light-sensitive material was prepared in such a manner that the following eight layers were coated in order over a paper support which had been coated on both sides with polyethylene resin and treated by a corona discharge. The amounts given hereinafter are in terms of the amount per sq. meter, unless otherwise stated. Layer 1 ... A layer containing 1.0 g of gelatin Layer 2 ...A layer containing 1.2 g of gelatin; 0.38 g in terms of silver content of a blue-sensitive silver chlorobromide emulsion comprising silver chloride (99.7 mole%). in cubic crystal form, with an average grain size of 0.85µm, gold-sulfur sensitized and containing blue-sensitive sensitizing dye A-12; 0.44 g of DBP or H-2 dissolved with 0.88 g of yellow coupler Y-1 and 0.015 g of 2,5-di-t-octylhydroquinone (hereinafter called HQ-1); and potassium bromide in an amount of 0.5 mole% per mole of AgX. Layer 3 ... A layer containing 0.7 g of gelatin Layer 4 ... A layer containing 1.25 g of gelatin; 0.32 g of a green-sensitive silver chlorobromide emulsion which comprised silver chloride of 99.5 mole%. in cubic crystal form, in an average grain size of 0.38µm, gold-sulfur sensitized and containing green-sensitive sensitizing dye B-5; 0.2 g of DBP or H-2 dissolved with 0.53 g of magenta coupler M-1 and 0.015 g of HQ-1; and potassium bromide in an amount of 0.6 mole% per mole of AgX. Layer 5 ... A layer containing 1.2 of gelatin; and 0.35 g of DBP dissolved therein with 0.08 of HQ-1 and 0.5 g of UV absorbent UV-1 Layer 6 ... A layer containing 1.4 g of gelatin; 0.25 g of a red-sensitive silver chlorobromide emulsion which comprised silver chloride of 99.3 mole%. in cubic crystal form, in an average grain size of 0.45 µm, gold-sulfur sensitized and containing red-sensitive sensitizing dye D-8; 0.18 g of DBP or H-2 dissolved with 0.50 g of the exemplified cyan coupler C-1 and 0.02 g of HQ-1; and potassium bromide in an amount of 1.0 mole% per mole of AgX. Layer 7 ... A layer containing 1.0 g of gelatin; and 0.14 g of DBP dissolved therein with 0.032 g of HQ-1 and 0.2 g of UV absorbent UV-1. Layer 8 ... A layer containing 0.5 g of gelatin Into layers 1, 3, 5 and 8, HD-1 was further added as a hardener in an amount of 0.017 g per g of the gelatin, respectively. In the above sample, the times at which the water-soluble substances and high boiling organic solvents were added to the emulsion layers were the same as in Example-1. In the same manner as in Examples-1 and 2, after an emulsion coating liquid was prepared, the coated samples were prepared by coating the resulted coating liquid immediately after the liquid was prepared, three hours thereafter and six hours thereafter, respectively. The sensitometries were then carried out. The results thereof are shown in Table-6, below. Sample No. High boiling organic solvent Layer relative sensitivity Remark Immediate After 3 hrs After 6 hrs 31 DBP Blue sensitive layer 100 82 70 Comparative sample Green sensitive layer 100 87 78 Red sensitive layer 100 75 61 32 H-2 Blue-sensitive layer 100 101 98 Invention sample Green sensitive layer 100 100 99 Red sensitive layer 100 98 96 As is obvious from the above Table, in Sample No. 31 which contained DBP and potassium bromide, it was found that every three layers thereof were desensitized when the coating liquid was aged and the color sensitivities thereof were also seriously unbalanced. In contrast, in Sample 32 relating to the invention, it was found that the aging stability thereof was remarkably improved and the sensitivity balance thereof was also particularly marked, so that the sample relating to the invention was an exceptional silver halide color photographic light-sensitive material.

Claims: A silver halide photographic light-sensitive material comprising a support bearing at least one silver halide emulsion layer thereon, wherein at least one silver halide emulsion layer comprises silver halide grains having a silver chloride content of not less than 90 mol%, a water soluble bromide in an amount from 0.05 mol% to 2 mol% per mol of silver halide, and a coupler dispersed in a high boiling organic solvent having a dielectric constant not exceeding 6.0 (measured at 30°C). The silver halide photographic light-sensitive material according to claim 1, wherein the amount of said water-soluble bromide contained in said silver halide emulsion layer is from 0.1 mol% to 1.5 mol% per mol of silver halide. The silver halide photographic light-sensitive material according to claim 2, wherein the amount of said water soluble-bromide contained in said silver halide emulsion layer is from 0.15 mol% to 1 mol% of silver halide. The silver halide photographic light-sensitive material according to any one of claims 1 to 3, wherein said high boiling organic solvent is a phthalic ester, a phosphoric ester, an organic acid amide, a ketone or a hydrocarbon, which has a dielectric constant not exceeding 6.0. The silver halide photographic light-sensitive material according to claim 4, wherein said high boiling organic solvent is a said phthalic ester or phosphoric ester. The silver halide photographic light-sensitive material according to claim 5, wherein said high boiling organic solvent is a phthalic ester represented by the following formula HA: wherein R H1 and R H2 each independently represent an alkyl group, an alkenyl group or an aryl group, provided that a total number of carbon atoms in the groups represented by R H1 and R H2 , taken together, is from 9 to 32. The silver halide photographic light-sensitive material according to claim 5, wherein said high boiling organic solvent is a phosphoric ester represented by the following formula HB: wherein R H3 , R H4 and R H5 each independently represent an alkyl group, an alkenyl group or an aryl group, provided that the total number of carbon atoms in the groups represented by R H3 , R H4 and R H5 , taken together, is from 24 to 54. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein the amount of said high boiling organic solvent contained in said silver halide emulsion layer is from 0.01 mol to 10 mol of silver halide. The silver halide photographic light-sensitive material according to claim 8, wherein the amount of said high boiling organic solvent contained in said silver halide emulsion layer is from 0.05 mol to 5 mol per mol of silver halide. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein the silver chloride content of said silver halide grains is not less than 95 mol%. The silver halide photographic light-sensitive material according to claim 10, wherein the silver chloride content of said silver halide grains is not less than 99 mol%. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein said silver halide grains have an average grain size of from 0.2µ m to 1.6µ m. The silver halide photographic light-sensitive material according to claim 12, wherein said silver halide grains have an average grain size of from 0.25µ m to 1.2µ m. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein said silver halide grains have a grain size distribution represented by a variation coefficient of not more than 0.22. The silver halide photographic light-sensitive material according to claim 14, wherein said silver halide grains have a grain size distribution represented by a variation coefficient of not more than 0.15. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein said silver halide emulsion layer contains a mercapto compound represented by the following formula S: wherein Q represents a group of atoms necessary to complete a five- or six-membered heterocyclic ring condensed with a benzene ring and M represents a hydrogen atom or a cation. The silver halide photographic light-sensitive material according to claim 16, wherein the amount of said mercapto compound represented by the formula S contained in said silver halide emulsion layer is from 1 x 10⁻⁶ to 1 x 10⁻¹ mol per mol of silver halide. The silver halide photographic light-sensitive material according to claim 17, wherein the amount of said mercapto compound represented by the formula S contained in said silver halide emulsion layer is from 1 x 10⁻⁵ to 1 x 10⁻² mol per mol of silver halide. The silver halide photographic light-sensitive material according to any one of the preceding claims, wherein the silver halide emulsion of said silver halide emulsion layer is sensitized by a sensitizing dye represented by the following formula A: wherein Z₁₁ and Z₁₂ each independently represent a group of atoms necessary to complete a benzoxazole nucleus, a naphthoxazole nucleus, a benzoselenazole nucleus, a naphthoselenazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzoimidazole nucleus, a naphthoimidazole nucleus, a pyridine nucleus or quinoline nucleus; R₂₁ and R₂₂ each independently represent an alkyl group, an alkenyl group or an aryl group; R₂₃ represents hydrogen, methyl or ethyl; X₁⁻ represents an anion and ℓ is an integer of 0 or 1. The silver halide photographic light-sensitive material according to any one of claims 1 to 18, wherein the silver halide emulsion of said silver halide emulsion layer is sensitized by a sensitizing dye represented by the following formula B: wherein Z₁₁ and Z₁₂ each independently represent a group of atoms necessary to complete a benzene ring or a naphthalene ring which are condensed to the oxazole ring, R₂₁ and R₂₂ each independently represent an alkyl group, an alkenyl group or an aryl group; R₂₃ represents hydrogen or alkyl having from 1 to 3 carbon atoms; X₁⁻ represents an anion and n is an integer of 0 or 1. A process for preparing a silver halide photographic light-sensitive material comprising a support bearing at least one silver halide emulsion layer thereon, comprising incorporating silver halide grains having a silver chloride content of not less than 90 mol%, into at least one of silver halide emulsion layer, incorporating a water-soluble bromide in an amount from 0.05 mol% to 2 mol% per mol of silver halide into said emulsion layer after completion of chemical ripening of said silver halide grains, and further incorporating a coupler dispersed in a high boiling organic solvent having a dielectric constant not exceeding 6.0 (measured at 30°C) into said silver halide emulsion layer. A process according to claim 21, wherein said water-soluble bromide is incorporated into the silver halide emulsion prepared as a coating liquid for preparing said silver halide emulsion layer. A process according to claim 21 or 22, wherein the silver halide photographic light-sensitive material is as claimed in any one of claims 2 to 20. A process comprising developing a silver halide photographic material as claimed in any one of claims 1 to 20 with a color developer for 30 seconds to 50 seconds. A process comprising developing a silver halide photographic light-sensitive material as claimed in any one of claims 1 to 20 with a color developer containing no benzyl alcohol.

Inventors: OHBAYASHI, KEIJI, OKUMURA, MITSUHIRO, TANAKA, SHIGEO
Applicants: KONICA CORPORATION
Application year: 1988
Main classification: G03C7
IPC codes: G03C1, G03C7