SILVER HALIDE PHOTOGRAPHIC MATERIALS

Abstract: A silver halide photographic material exhibiting im­ proved interimage effects and having improved sharpness and graininess is disclosed. The material contains at least one compound represented by formula (I) or formula (II): wherein R¹ represents a straight or branched chain alkylene, alkenylene or aralkylene group, or an arylene group; R² represents a hydrogen atom, or a substituted or unsubsti­ tuted alkyl, aryl, alkenyl or aralkyl group; X represents a hydrogen atom, an alkali metal atom, an ammonium group or a precursor capable of providing a hydrogen atom or an alkali metal atom under an alkaline condition; Z¹ and Z² each represents a polar group; and n represents 0 or 1.

Description: This invention relates to a silver halide photographic material having improved interimage effects, improved sharpness, and improved graininess. In silver halide color photographic materials, it is well known that color development induces reaction between an oxidized aromatic primary amine color developing agent with a coupler to produce an indophenol dye, an indoaniline dye, an indamine dye, an azomethine dye, a phenoxazine dye, a phenazine dye, or a like dye to thereby form a color image. In this photographic system, color reproduction is generally achieved by a subtractive color process using silver halide emulsions selectively sensitive to each of blue, green, and red light, and yellow-,magenta-, and cyan-dye-forming agents (couplers) that are complementary to the silver halide emulsions, respectively. For example, acylacetanilide and dibenzoylmethane couplers are used for formation of a yellow dye image; pyrazolone, pyrazolobenzimidazole, pyrazolopyrazole, pyrazolotriazole, cyanoacetophenone, and indazolone couplers are typically used for formation of a magenta dye image; and phenol and naphthol couplers are mostly used for formation of a cyan dye image. Dyes produced by these couplers do not have ideal absorption spectra. In particular, magenta and cyan dyes have disadvantages for color reproduction of color photographic light-sensitive materials, such as a broad absorption spectrum or side absorption in a short wavelength region. Side absorption in a short wavelength region tends to cause reduction in saturation. The reduced saturation can be restored to some extent by manifestation of interimage effects. Details of interimage effects are described, e.g., in Hanson, et al., Journal of the Optical Society of America, Vol. 42, pp. 663-669, A. Thiels, Zeitschrift für Wissenschaftliche Photographie, Photophysique und Photo-chemie, Vol. 47, pp. 106-118 and 246-255. It has been proposed to obtain favorable interimage effects by introducing diffusible 4-thiazolin-2-thione into a light-exposed color reversal photographic element (U.S. Patent 3,536,486) or an unexposed color reversal photographic element (U.S. Patent 3,563,467). Japanese Patent Publication No. 34169/73 discloses that remarkable interimage effects can be exerted in a color photographic light-sensitive material by reducing silver halides to silver in the presence of an N-substituted-4-thiazoline-2-thione compound. Interimage effects obtained by providing a colloidal silver-containing layer between a cyan layer and a magenta layer in a color reversal photographic element are described in Research Disclosure, RD No. 13116 (March, 1975). Furthermore, U.S. Patent 4,082,553 discloses that good interimage effects can be obtained in a color reversal light-sensitive material having a layer structure that allows movement of iodide ions during development, one layer of which contains latent image-forming silver haloiodide grains and another layer of which contains latent image-forming silver halide grains and silver halide grains having their surfaces fogged so that they may be developed irrespective of imagewise exposure. However, the above-described conventional techniques fail to produce fully satisfactory interimage effects, or the use of a colloidal silver-containing layer or the introduction of fogged silver halide grains brings about a reduction in color density in color reversal light-sensitive materials. It is also known to produce interimage effects by using a coupler capable of releasing a development inhibitor (i.e., DIR coupler), e.g., a benzotriazole derivative or a mercapto compound, upon reacting with an oxidation product of a color development agent, or using a hydroquinone compound, capable of releasing a development inhibitor, e.g, an iodine ion or a mercapto compound. However, use of these development inhibitor-releasing compounds is accompanied by serious desensitization or reduction of color density and has, therefore, been narrowly limited in its applications. DE-A-3203661 discloses photographic silver halide materials comprising a thiadiazole compound having an amine substituent. JP-A-57164734 discloses photographic silver halide materials comprising thiadiazole compounds having a -SO₃Na or -SO₂NH₄ substituent. JP-A-51102639 discloses photographic silver halide materials comprising 5-mercapto-1,3,4-thiadiazole compounds. It is the object of this invention to provide a silver halide photographic material which exerts great interimage effects without impairing other photographic properties and which has excellent sharpness and graininess. This object is accomplished by a silver halide photographic material comprising at least one thiadiazole compound characterized in that said thiadiazole compound is represented by formula (I) or formula (II) wherein R¹ represents a straight or branched chain alkylene, alkenylene or aralkylene group, or an arylene group; R² represents a hydrogen atom, or a substituted or unsubstituted alkyl, aryl, alkenyl or aralkyl group; X represents a hydrogen atom, an alkali metal atom, an ammonium group, or a precursor capable of providing a hydrogen atom or an alkali metal under an alkaline condition; Z¹ represents a quaternary ammonium group, an alkoxy group, an alkylthio group, an arylthio group, a heterocyclic oxy group, a heterocyclic thio group, a carbamoyl group, a sulfamoyl group, an acyloxy group, a ureido group, a thioureido group, or a sulfonyloxy group; Z² represents a quaternary ammonium group, an alkoxy group, an alkylthio group, an arylthio group, a heterocyclic oxy group, a heterocyclic thio group, a carbamoyl group, a sulfamoyl group, an acyloxy group, a ureido group, a thioureido group, a sulfonyloxy group, a substituted or unsubstituted amino group or a salt thereof, an aryloxy group, a heterocyclic group, or a cyano group,and n represents 0 or 1 In the above-described formulae (I) and (II), R¹ represents a straight chain or branched chain alkylene group, preferably having from 1 to 15 carbon atoms, more preferably from 1 to 10 carbon atoms (e.g., a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group or a 1-methylethylene group), a straight chain or branched chain alkenylene group, preferably having from 2 to 15 carbon atoms, more preferably from 2 to 10 carbon atoms (e.g., a vinylene group or a 1-methylvinylene group), a straight chain or branched chain aralkylene group, preferably having from 7 to 30 carbon atoms, more preferably from 7 to 20 carbon atoms (e.g., a benzylidene group) or an arylene group, preferably having from 6 to 30 carbon atoms, more preferably from 6 to 20 carbon atoms (e.g., a phenylene group or a naphthylene group), with an alkylene group being particularly preferred. R² represents a hydrogen atom, a substituted or unsubstituted alkyl group, preferably having from 1 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group or a 2-dimethylaminoethyl group), a substituted or unsubstituted aryl group, preferably having from 6 to 20 carbon atoms (e.g., a phenyl group or a 2-methylphenyl group), a substituted or unsubstituted alkenyl group, preferably having from 2 to 10 carbon atoms (e.g., a propenyl group or a 1-methylvinyl group) or a substituted or unsubstituted aralkyl group, preferably having from 7 to 15 carbon atoms (e.g., a benzyl group or a phenethyl group), with a hydrogen atom and an alkyl group being particularly preferred. X represents a hydrogen atom, an alkali metal atom (e.g., a sodium atoms or a potassium atom), an ammonium group, preferably having from 3 to 30 carbon atoms (e.g., a trimethylammoniumyl chloride group or a dimethylbenzylammoniumyl chloride group) or a precursor capable of providing a hydrogen atom or an alkali metal atom under an alkaline condition at a pH of from 8.5 to 13.5, preferably from 9.0 to 12.5 (e.g., an acetyl group, a cyanoethyl group or a methanesulfonylethyl group). The polar substituent as represented by Z¹ or Z² includes a quaternary ammonium group, preferably having from 3 to 30 carbon atoms (e.g., a trimethylammoniumyl chloride groups or a dimethylbenzylammoniumyl chloride group), an alkoxy group, preferably having from 1 to 15 carbon atoms (e.g., a methoxy group, an ethoxy group or a 2-hydroxyethoxy group), an alkylthio group, preferably having from 1 to 15 carbon atoms (e.g., a methylthio group or a butylthio group), an arylthio group, preferably having from 6 to 20 carbon atoms (e.g., a phenylthio group), a heterocyclic oxy group, preferably having from 1 to 20 carbon atoms (e.g., a 2-pyridyloxy group or a 2-imidazolyloxy group), a heterocyclic thio group, preferably having from 1 to 20 carbon atoms (e.g., a 2-benzthiazolylthio group or a 4-pyrazolylthio group), a carbamoyl group, preferably having from 1 to 10 carbon atoms (e.g., an unsubstituted carbamoyl group or a methylcarbamoyl group), a a sulfamoyl group, preferably having from 0 to 10 carbon atoms (e.g., an unsubstituted sulfamoyl group or a methylsulfamoyl group), an acyloxy group, preferably having from 2 to 15 carbon atoms (e.g., an acetyloxy group or a benzoyloxy group), a ureido group, preferably having from 1 to 10 carbon atoms (e.g., an unsubstituted ureido group, a methylureido group or an ethylureido group), a thioureido group, preferably having from 1 to 10 carbon atoms (e.g., an unsubstituted thioureido group or a methylthioureido group) and a sulfonyloxy group, preferably having from 1 to 15 carbon atoms (e.g., a methanesulfonyloxy group or a p-toluenesulfonyloxy group). Z² in formula (II) additionally includes a substituted or unsubstituted amino group inclusive of its salt, preferably having from 0 to 10 carbon atoms (e.g., an amino group, an amino hydrochloride group, a methylamino group, a dimethylamino group, a dimethylamino hydrochloride group, a diethylamino group, a diethylamino hydrochloride group, a dibutylamino group, a dipropylamino group or an N-dimethylaminoetyl-N-methylamino group), an aryloxy group, preferably having from 6 to 20 carbon atoms (e.g., a phenoxy group), a heterocyclic group, preferably having from 1 to 20 carbon atoms (e.g., a 1-morpholino group, a 1-piperidino group, a 2-pyridyl group, a 4-pyridyl group, a 2-thienyl group, a 1-pyrazolyl group, a 2-imidazolyl group, a 2-tetrahydrofuryl group or a tetrahydrothienyl group) and a cyano group. Of the groups for Z¹ and Z², a quaternary ammonium group, a carbamoyl group and a ureido group are preferred for Z¹ and Z², and in addition an amino group and a heterocyclic group are preferred for Z². In formulae (I) and (II), Z¹ and Z² do not include a sulfonic acid group, a carboxylic acid group, a hydroxy group, or an alkoxycarbonyl group (e.g., a methoxycarbonyl group or an ethoxycarbonyl group). Preferred compounds of formula (I) are those wherein n represents 1. In a black-and-white photographic light-sensitive material according to the present invention comprising two or more silver halide emulsion layers, effects analogues to interimage effects in multi-layer color photographic light-sensitive materials are observed between the two silver halide emulsion layers. For example, when a black-and-white light-sensitive material comprises a higher sensitive emulsion layer generally having larger silver halide grains and a lower sensitive emulsion layer generally having smaller silver halide grains, the higher sensitive emulsion layer is also developed in a high exposure region where the lower sensitive layer can be developed. In this case, if the compound represented by formula (I) or (II) used according to the present invention is incorporated into the higher sensitive layer and/or the lower sensitive layer, the lower sensitive emulsion functions to restrain development of the higher sensitive emulsion in the high exposure region. As a result, the amount of developed silver of the higher sensitive silver halide emulsion generally having larger grains can be decreased to thereby improve graininess in the high exposure region. Further, according to the present invention, improvements in sharpness can be obtained in both color photographic light-sensitive materials and black-and-white photographic light-sensitive materials, having at least one silver halide emulsion layer. An intralayer development inhibition effect is also produced simultaneously with the interimage effects (interlayer effects) among different silver halide emulsion layers. This intralayer effect shows itself at the edge between a high exposure region and a low exposure region in each silver halide emulsion layer (edge effect). If at least one of the compounds of formula (I) or formula (II) is incorporated into the silver halide emulsion layer, inhibition on development works at the edge from the high exposure region to the low exposure region. This development inhibition at the edge makes the edge clearer and thus improves sharpness. Specific examples of the compounds represented by formula (I) and formula (II) used according to the present invention are shown below. The compounds of formula (I) or (II) which can be used in the present invention can be synthesized by the process described in Advances in Heterocyclic Chemistry), Vol. 9, pp. 165-209 (1968). Typical examples of synthesis are shown below. SYNTHESIS EXAMPLE 1 Synthesis of Compound (2) To 300 ml of acetone was added 15 g of 2,5-dimercapto-1,3,4-thiadiazole, and 22 ml of a 28% sodium methoxide solution and 12 g of β-chloropropionamide were added thereto. To the mixture was further added 15 g of sodium iodide, followed by heat-refluxing for 20 h. After cooling, the crystals formed were filtered, washed with water and recrystallized from a mixed solvent of dimethylformamide and methanol to obtain 12.0 g of Compound (2) having a melting point of from 175 to 177°C. SYNTHESIS EXAMPLE 2 Synthesis of Compound (4) In 100 ml of ethanol were dissolved 15.0 g of 2,5-dimercapto-1,3,4-thiadiazole and 20 ml of a 28% sodium methoxide solution under heating. To the resulting solution was added dropwise 13.5 g of 2-chloroethylurea. After the dropwise addition, the reaction mixture was heated under reflux for 4 h. The reaction mixture was then poured into 700 ml of ice-water, and the precipitated crystals were filtered and recrystallized from methanol to provide 16.4 g of Compound (4) having a melting point of from 174 to 176°C. SYNTHESIS EXAMPLE 3 Synthesis of Compound (3) To 150 ml of ethanol was added 17.6 g of 1-(3-dimethylaminopropyl)thiosemicarbazide, and 7.9 g of potassium hydroxide was dissolved therein. Then, 34.3 g of carbon disulfide was added thereto dropwise at room temperature, followed by heating under reflux for 5 h. After cooling, the crystals formed were filtered and recrystallized from methanol and concentrated hydrochloric acid to obtain 11.3 g of Compound (3) having a melting point of from 204 to 205°C. SYNTHESIS EXAMPLE 4 Synthesis of Compound (5) In 200 ml of ethanol were dissolved 30.0 g of 2,5-dimercapto-1,3,4-thiadiazole and 40 ml of a 28% sodium methoxide solution under heating, and 20.8 g of methoxyethyl chloride was added dropwise to the solution. After the dropwise addition, the mixture was refluxed for 2 h. After completion of the reaction, the reaction mixture was filtered, and the filtrate was dried under reduced pressure to a solid, which was then recrystallized from ethyl acetate and n-hexane to obtain 29.8 g of Compound (5) having a melting point of from 59 to 60°C. SYNTHESIS EXAMPLE 5 Synthesis of Compound (7) In 100 ml of ethanol were dissolved 10.5 g of 2,5-dimercapto-1,3,4-thiadiazole and 14 ml of a 28% sodium methoxide solution under heating, and 8.5 g of methylthioethyl chloride was then added thereto dropwise. After the addition, the mixture was heated under reflux for 3 h. After completion of the reaction, the reaction mixture was poured into 1 l of ice-water, and the precipitated crystals were filtered and recrystallized from ethyl acetate and n-hexane to provide 8.6 of Compound (7) having a melting point of from 75 to 76°C. SYNTHESIS EXAMPLE 6 Synthesis of Compound (29) In 100 ml of n-butanol were dissolved 15.0 g of 2,5-dimercapto-1,3,4-thiadiazole and 17.4 g of 2-chloroethyltrimethylammonium chloride under heating, and 7.8 ml of pyridine was then dropwise added thereto, followed by heating under reflux for 3 h. After completion of the reaction, the precipitated crystals were filtered and recrystallized from methanol to obtain 18.1 g of Compound (29) having a melting point of from 222 to 225°C. In multi-layer color photographic light-sensitive materials to which the present invention is applied, the compound of formula (I) or (II) is incorporated into at least one silver halide emulsion layer or a layer adjacent thereto, such as a yellow filter layer, an antihalation layer, an intermediate layer or a protective layer. Preferably, the compound is incorporated in a silver halide emulsion layer. In black-and-white photographic light-sensitive materials to which the present invention is applied, the compound of formula (I) or (II) is incorporated in a silver halide emulsion layer and/or a protective layer. The amount of the compound (I) or (II) to be added varies depending on the properties, end use, and/or method of development of the silver halide photographic materials to be used, but, in general, preferably ranges from 10⁻¹ to 10⁻⁵ mols, and more preferably from 3 x 10⁻² to 3 x 10⁻⁴ mols, per mol of silver halide in the layer in which the compound is incorporated or in layers adjacent thereto when silver halide is not contained in the layer in which the compound is incorporated. The compound of formula (I) or (II) can be incorporated into the light-sensitive material by dissolving it in a solvent commonly employed in photographic light-sensitive materials, such as water, methanol, ethanol, propanol or a fluorinated alcohol, and adding the solution to a hydrophilic colloid. Addition to a silver halide emulsion layer may be effected at any stage selected depending upon the end use, e.g., during grain formation of a silver halide emulsion, during physical ripening, immediately before, during or after chemical sensitization, or at the time of preparing a coating composition. Light-sensitive materials of the present invention include, for example, color photographic light-sensitive materials, such as color negative films, color reversal films (either coupler-in-emulsion type or coupler-in-developer type), color papers, color positive films, color reversal papers, color diffusion transfer materials or dye transfer materials; and black-and-white photographic light-sensitive materials, such as black-and-white negative films, black-and-white photographic papers, X-ray films or lith films. Binders or protective colloids which can be used in emulsion layers or intermediate layers of light-sensitive materials preferably include gelatin, but other hydrophilic colloids may also be employed alone or in combination with gelatin. Gelatin to be used in the present invention may be either lime-processed or acid-processed. Details for gelatin preparation are described, for example, in Arthur Veis, The Macromolecular Chemistry of Gelatin, Academic Press (1964). In photographic emulsion layers, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide and silver chloride may be employed. In particular, good results can be obtained when at least one photographic emulsion layer contains silver chloroiodobromide, silver iodobromide, or silver chloroiodide having an iodine content of from 0.5 to 15 mol%. The mean grain size of silver halide grains in the photographic emulsion (the grain size being defined as the grain diameter if the grain has a spherical or a nearly spherical form and as the length of the edge if the grain has a cubic form, and being averaged based on projected areas of the grains) is not particularly restricted, but is preferably 3 µm or less. Grain size distribution may be either narrow or broad. Silver halide grains in the photographic emulsion may have a regular crystal form, such as a cube and an octahedron, an irregular crystal form, such as a sphere and a plate-like (tabular), or a composite form thereof. Further, silver halide grains may be a mixture of grains having various crystal forms. An emulsion wherein tabular silver halide grains having a diameter 5 times the thickness thereof occupy 50% or more of the total projection area may also be employed. The individual silver halide grains may comprise a core and an outer shell or may be homogeneous. Further, they may be either those grains where a latent image is predominantly formed on the surface thereof or those grains where a latent image is predominantly formed in the interior thereof. Photographic emulsions which can be used in the present invention can be prepared according to conventional methods as described, for example, in P. Glafkides, Chiemie et Physique Photographique, Paul Montel (1967); G.F. Duffin, Photographic Emulsion Chemistry, Focal Press (1966), V.L. Zelikman et al., Making and Coating Photographic Emulsion, Focal Press (1964). In more detail, photographic emulsions can be prepared according to any of the acid process, the neutral process or the ammonia process. Methods for reacting a water-soluble silver salt with a water-soluble halide include a single jet method, a double jet method or a combination thereof. A method in which silver halide grains are produced in the presence of excess silver ions (the so-called reverse mixing method) can also be used. Further, the so-called controlled double jet method, in which the pAg of the liquid phase wherein silver halide grains are precipitated is maintained constant, can also be employed. According to this method, silver halide emulsions in which the grains have a regular crystal form and a substantially uniform size distribution can be obtained. Two or more silver halide emulsions prepared separately may be employed in the form of a mixture. In the process of producing silver halide grains or physically ripening the silver halide grains, for example, cadmium salts, zinc salts, lead salts, thallium salts, iridium salts or complex salts thereof, rhodium salts or complex salts thereof, iron salts or complex salts thereof, may be present. Typically, the silver halide emulsion is chemically sensitized. Chemical sensitization can be carried out by processes as described, e.g., in H. Frieser (ed.), Die Grundlagen der Photographischen Prozesse mit Silberhalogeniden, Akademische Verlagsgesellschaft, pp. 675-734 (1968). More specifically, chemical sensitization can be carried out by sulfur sensitization using a compound containing sulfur capable of reacting with active gelatin or silver ions (e.g., thiosulfates, thioureas, mercapto compounds or rhodanines), reduction sensitization using a reducing material (e.g., stannous salts, amines, hydrazine derivatives, formamidinesulfinic acid or silane compounds), noble metal sensitization using a noble metal compound (e.g., gold complex salts, and complex salts of Periodic Table Group VIII metals, e.g., Pt, Ir or Pd) or a combination thereof. The photographic emulsions to be used in the present invention can contain various compounds for the purpose of preventing fog in the preparation, preservation, or photographic processing, or for stabilizing photographic properties. Examples of such compounds include azoles, such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (particularly 1-phenyl-5-mercaptotetrazole): mercaptopyrimidines; mercaptotriazines; thioketo compounds, such as oxazolinethione; azaindenes, such as triazaindenes, tetraazaindenes (particularly, 4-hydroxy-substituted-(1,3,3a,7)tetraazaindenes), pentaazaindenes; benzenethiosulfonic acid; benzenesulfinic acid; benzenesulfonic acid amide; and many other compounds known as antifoggants or stabilizers. Photographic emulsion layers or other hydrophilic colloidal layers of the light-sensitive materials of the present invention may contain a wide variety of surface active agents for various purposes, for example, as a coating aid or for prevention of static charge, improvement of slipperiness, as a dispersing agent, for prevention of adhesion, improvement of photographic characteristics (e.g., acceleration of development, increase in contrast or sensitization. For the purpose of increasing sensitivity or contrast or acceleration of development, the photographic emulsion of the light-sensitive materials in accordance with the present invention may contain, for example, polyalkylene oxides or derivatives thereof, e.g., ethers, esters and amines, thioether compounds, thiomorpholines, quaternary ammonium salt compounds, urethane derivatives, urea derivatives, imidazole derivatives or 3-pyrazolidones. The photographic emulsion layers or other hydrophilic colloidal layers of the light-sensitive materials of the present invention may further contain a dispersion of a water-insoluble or sparingly water-soluble synthetic polymer for the purpose of improving dimensional stability. Examples of such a polymer includes those comprising, as a monomer component, one or more of alkyl (meth)acrylates, alkoxyalkyl (meth)-acrylates, glycidyl (meth)acrylate, (meth)acrylamide, vinyl esters (e.g., vinyl acetate), acrylonitrile, olefins and styrene, or a combination of these monomer components and acrylic acid, methacrylic acid, α,β-unsaturated dicarboxylic acids, hydroxyalkyl (meth)acrylates, sulfoalkyl (meth)acrylates or styrenesulfonic acid. The photographic emulsions which can be used in the present invention may be spectrally sensitized with methine dyes or others. Dyes to be used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes, with cyanine dyes, merocyanine dyes and complex merocyanine dyes being particularly useful. Any nucleus conventionally employed in cyanine dyes as a basic heterocyclic nucleus may be applied to these dyes. Examples of such nuclei include a pyrroline nucleus, an oxazoline nucleus, a thiazoline nucleus, a pyrrole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, an imidazole nucleus, a tetrazole nucleus and a pyridine nucleus; the above-described nuclei to which an alicyclic hydrocarbon ring is fused; and the above-described nuclei to which an aromatic hydrocarbon ring is fused, e.g., an indolenine nucleus, a benzindolenine nucleus, an indole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzoselenazole nucleus, a benzimidazole nucleus or a quinoline nucleus. These nuclei may have a substituent on their carbon atoms. The merocyanine dyes or complex merocyanine dyes may have a 5- to 6-membered heterocyclic nucleus having a ketomethylene structure, e.g., a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thiooxazolidine-2,4-dione nucleus, a thiazolidine-2,4-dione nucleus, a rhodanine nucleus or a thiobarbituric acid nucleus. These sensitizing dyes may be used either individually or in combinations thereof. Combinations of sensitizing dyes can be desirably employed for the purpose of supersensitization. The photographic emulsion may further contain, in combination with the sensitizing dye, a substance which neither exhibits spectral sensitizing activity per se nor substantially absorbs visible light, but which shows supersensitizing activity, when used together with the sensitizing dye. Examples of such substances are aminostyryl compounds substituted with a nitrogen-containing heterocyclic group (U.S. Patents 2,933,390 and 3,635,721), aromatic organic acidformaldehyde condensates (U.S. Patent 3,743,510), cadmium salts or azaindene compounds. The present invention is applicable to multi-layer multicolor photographic materials having at least two layers being different in spectral sensitivity. Multi-layer neutral color photographic materials usually comprise a support having provided thereon at least one red-sensitive emulsion layer, at least one green-sensitive emulsion layer and at least one blue-sensitive emulsion layer. The order of these layers may arbitrarily be selected according to the intended purpose. For natural color reproduction, typically the red-sensitive emulsion layer contains a cyan-forming coupler, the green-sensitive emulsion layer contains a magenta-forming coupler, and the blue-sensitive emulsion layer contains a yellow-forming coupler. However, other combinations may also be employed, if desired. Photographic emulsion layers or light-insensitive layers of the photographic light-sensitive materials according to the present invention may contain color forming couplers, i.e., compounds capable of developing a color upon oxidative coupling with an aromatic primary amine developing agent (e.g., phenylenediamine derivatives or aminophenol derivatives) in color development processing. Examples of such couplers include 5-pyrazolone couplers, pyrazolobenzimidazole couplers, pyrazolotriazole couplers, pyrazoloimidazole couplers, pyrazolopyrazole couplers, pyrazolotriazole couplers, pyrazolotetrazole couplers, cyanoacetylcumarone couplers and open-chain acylacetonitrile couplers as magenta couplers; acylacetamide couplers (e.g., benzoyl acetanilides or pivaloylacetanilides) as yellow couplers; and naphthol couplers or phenol couplers as cyan couplers. It is desirable that these couplers have a hydrophobic group called ballast group in their molecule and are thereby non-diffusible or they have a polymerized form. These couplers may be either 4-equivalent or 2-equivalent to silver ions. In addition to these couplers, colored couplers having a color correcting effect or couplers capable of releasing a development inhibitor with the progress of development (so-called DIR couplers) may also be used. Moreover, colorless DIR coupling compounds which produce a colorless product upon coupling reaction and release a development inhibitor may also be used. Further, other compounds capable of releasing a development inhibitor with the progress of development may be used. In order to satisfy various requirements demanded for light-sensitive materials, the above-described couplers can be incorporated into two or more different layers, or two or more of these couplers and the like may be incorporated into the same layer. Couplers can be incorporated into silver halide emulsion layers by known processes, e.g., the process disclosed in U.S. Patent 2,322,027. For example, the coupler is dissolved in a high boiling organic solvent, such as an alkyl phthalate (e.g., dibutyl phthalate or dioctyl phthalate), a phosphoric ester (e.g., diphenyl phosphate, triphenyl phosphate, tricresyl phosphate or dioctylbutyl phosphate), a citric ester (e.g., tributyl acetylcitrate), a benzoic ester (e.g., octyl benzoate), an alkylamide (e.g., diethyllauryamide), a fatty acid ester (e.g., dibutoxyethyl succinate or diethyl azelate), a trimesic ester (e.g., tributyl trimesate), or a low boiling organic solvent having a boiling point of from about 30 to 150°C, e.g., a lower alkyl acetate, ethyl propionate, sec-butyl alcohol, methyl isobutyl ketone, β-ethoxyethyl acetate or methyl cellosolve acetate, or a mixture of the high boiling organic solvent and the low boiling organic solvent, and the resulting coupler solution is then dispersed in a hydrophilic colloid. Couplers may also be incorporated into silver halide emulsion layers by a dispersion process using a polymer as described in Japanese Patent Publication No. 39853/76 and Japanese Patent Application (OPI) No. 59943/76. Couplers having an acid group, e.g., a carboxyl group or a sulfo group, can be introduced in a hydrophilic colloid as an alkaline aqueous solution. The photographic light-sensitive materials according to the present invention can contain an organic or inorganic hardener in the emulsion layers or other hydrophilic colloidal layers. Examples of the hardener to be used include chromium salts (e.g., chromium alum or chromium acetate), aldehydes (e.g., formaldehyde, glyoxal or glutaraldehyde), N-methylol compounds (e.g., dimethylolurea or methyloldimethylhydantoin), dioxane derivatives (e.g., 2,3-dihydroxydioxane), active vinyl compounds (e.g., 1,3,5-triacryloyl-hexahydro-s-triazine or 1,3-vinylsulfonyl-2-propanol), active halogen compounds (e.g., 2,4-dichloro-6-hydroxy-s-triazine), mucohalogenic acids (e.g., mucochloric acid or mucophenoxychloric acid), either alone or in combinations thereof. When a hydrophilic colloidal layer in the light-sensitive materials of the present invention contains a dye or an ultraviolet absorbent, same may be mordanted with a cationic polymer. The light-sensitive materials of the present invention may contain a color fog preventing agent, such as hydroquinone derivatives, aminophenol derivatives, gallic acid derivatives of ascorbic acid derivatives. The hydrophilic colloidal layers of the light-sensitive materials of this invention may contain an ultraviolet absorbent, such as a benzotriazole compound substituted with an aryl group (e.g., those described in U.S. Patent 3,533,794), a 4-thiazolidone compound (e.g., those described in U.S. Patents 3,314,794 and 3,352,681), a benzophenone compound (e.g., those described in Japanese Patent Application (OPI) No. 2784/71), a cinnamic acid ester compound (e.g., those described in U.S. Patents 3,705,805 and 3,707,375), a butadiene compound (e.g., those described in U.S. Patent 4,045,229) and a benzoxazole compound (e.g., those described in U.S. Patent 3,700,455). Ultraviolet absorbing couplers (e.g., α-naphthol type cyan color forming couplers) or ultraviolet absorbing polymers may be used as ultraviolet absorbents. These ultraviolet absorbents may be mordanted or fixed to a specific layer. The hydrophilic colloidal layer of the light-sensitive materials of the present invention may contain water-soluble dyes as filter dyes or for prevention of irradiation or for various other purposes. Such water-soluble dyes include oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes, cyanine dyes and azo dyes, with oxonol dyes, hemioxonol dyes, and merocyanine dyes being particularly useful. In carrying out the present invention, the following known discoloration inhibitors may be used. Further, color image stabilizing agents may be used individually or in a combination of two or more thereof. The known discoloration inhibitors include hydroquinone derivatives, gallic acid derivatives, p-alkoxyphenols, p-oxyphenol derivatives and bisphenols. The light-sensitive materials according to the present invention can be processed by known processes with known processing solutions as described, e.g., in Research Disclosure RD No. 176, pp. 28-30 (December, 1978). The processing temperature is usually selected from 18 to 50°C, but lower or higher temperatures may also be employed. In photographic processing, the silver halide photographic materials of the present invention are subjected to black-and-white development, followed by fixing, in the case of black-and-white light-sensitive materials; or color development, bleaching and fixing in the case of color light-sensitive materials; or black-and-white development, reversal, color development, bleaching, followed by fixing in the case of color reversal light-sensitive materials. A first developer to be used in the present invention can contain a known developing agent. Examples of known developing agents include dihydroxybenzenes (e.g., hydroquinone), 3-pyrazolidones (e.g., 1-phenyl-3-pyrazolidone), aminophenols (e.g., N-methyl-p-aminophenol), 1-phenyl-3-pyrazolines, ascorbic acid, a heterocyclic compound having a skeleton like condensed 1,2,3,4-tetrahydroquinoline ring and indolene ring as disclosed in U.S. Patent 4,067,872. These developing agents may be used alone or in combinations thereof. The black-and-white developer which can be used in the present invention can contain, if desired, preservatives (e.g., sulfites or bisulfites), buffering agents (e.g., carbonates, boric acid, borates or alkanolamines), alkali agents (e.g., hydroxides or carbonates), dissolution aids (e.g., polyethylene glycols or esters thereof), pH-adjusters (e.g., acetic acid or like organic acids), sensitizers (e.g., quaternary ammonium salts), development accelerators, surface active agents, toning agents, defoaming agents, hardeners or viscosity-imparting agents. The first developer should contain a compound which functions as a silver halide solvent but, usually, the above-described sulfites added as preservatives can serve as silver halide solvents. Specific examples of these sulfites and other employable silver halide solvents include KSCN, NaSCN, K₂SO₃, Na₂SO₃, K₂S₂O₅, Na₂S₂O₅, K₂S₂O₃ and Na₂S₂O₃. A development accelerator is used for imparting a development accelerating property to the developer. In particular, one or more compounds that may be used either alone or in combination with the above-described silver halide solvent are those represented by formula (A) wherein R³ represents an alkylene group having from 2 to 10 carbon atoms which may contain an ether linkage; R⁴ represents a substituted or unsubstituted alkyl group having from 2 to 10 carbon atoms which may contain an ether linkage or an ester linkage, and d represents 0 or an integer of from 1 to 3. Addition of too small an amount of these silver halide solvents retards development progress, while addition of too large an amount generates fog in the silver halide emulsion. Accordingly, there is naturally set a preferred range of the amount of the silver halide solvent to be used, which can readily be determined by the one skilled in the art. For example, it is preferable to use SCN ⊖ in an amount ranging from 0.005 to 0.02 mol, and more preferably from 0.01 to 0.015 mol, per l of developer; and to use SO₃² ⊖ in an amount ranging from 0.05 to 1 mol, and more preferably from 0.1 to 0.5 mol, per l of developer. The compound represented by formula (A), when added to a black-and-white developer, is preferably used in an amount of from 5 x 10⁻⁶ to 5 x 10⁻¹ mol, and more preferably from 1 x 10⁻⁴ to 2 x 10⁻¹ mol, per liter of a developer. The thus prepared developer is adjusted to have a pH value sufficient to provide the desired density and contrast, preferably between about 8.5 and about 11.5. A fogging bath (reversing bath) which can be used in a reversal process can contain a known fogging agent, such as stannous ion complex salts, e.g,, a stannous ion-organic phosphoric acid complex salt (U.S. Patent 3,617,282), a stannous ion-organic phosphonocarboxylic acid complex salt (Japanese Patent Publication No. 32616/81), a stannous ion-aminopolycarboxylic acid complex salt (British Patent 1,209,050), etc., and boron compounds, e.g., a boron hydride compound (U.S. Patent 2,984,567) or a heterocyclic amine-boran compound (British Patent 1,011,000). Such a fogging bath has a broad range of pH over an acid to alkali side, i.e., from 2 to 12, preferably from 2.5 to 10, and more preferably from 3 to 9. A color developer which can be used in the present invention has a composition generally employed as a color developer, which contains an aromatic primary amine developing agent. Preferred examples of the aromatic primary amine color developing agent are p-phenylenediamine derivatives, e.g, N,N-diethyl-p-phenylenediamine, 2-amino-5-diethylaminotoluene, 2-amino-5-(N-ethyl-N-laurylamino)toluene, 4-[N-ethyl-N-(β-hydroxyethyl)amino]aniline, 2-methyl-4-[N-ethyl-N-(β-hydroxyethyl)amino]aniline, N-ethyl-N-(β-methanesulfoamidoethyl)-3-methyl-4-aminoaniline, N-(2-amino-5-diethylaminophenylethyl)methanesulfonamide, N,N-dimethyl-p-phenylenediamine, and 4-amino-3-methyl-N-ethyl-N-methoxyethylaniline, 4-amino-3-methyl-N-ethyl-N-β-ethoxyethylaniline and 4-amino-3-methyl-N-ethyl-N-β-butoxyethylaniline or salts thereof (e.g., sulfates, hydrochlorides, sulfites, p-toluenesulfonates, etc.) disclosed in U.S. Patents 3,656,950 and 3,698,525. The color developer can contain other known developer components. For example, one or a combination of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium tertiary phosphate, potassium tertiary phosphate, potassium metaborate or borax can be added as an alkali agent or buffer agent. The color developer can also contain a preservative, such as a sulfite (e.g., sodium sulfite, potassium sulfite, potassium bisulfite or sodium bisulfite) and hydroxylamine. The color developer can further contain, if desired, an optional development accelerator. Examples of the accelerator include various pyridinium compounds and other cationic compounds, cationic dyes, e.g., phenosafranine, and neutral salts, e.g., thallium nitrate or potassium nitrate, as typically described in U.S. Patent 2,648,604, Japanese Patent Publication No. 9503/69, and U.S. Patent 3,671,247; nonionic compounds, such as polyethylene glycol or its derivatives, polythioethers, as described in Japanese Patent Publication 9504/69 and U.S. Patents 2,533,990, 2,531,832, 2,950,970, and 2,577,127; organic solvents, organic amines, ethanolamine, ethylenediamine and diethanolamine, as described in Japanese Patent Publication No. 9509/69 and Belgian Patent 682,862; and compounds as described in L.F.A. Mason, Photographic Processing Chemistry, pp. 40-43, Focal Press (1966). The color developer can furthermore contain a water softener, such as aminopolycarboxylic acids, e.g., ethylenediaminetetraacetic acid, nitrilotriacetic acid, cyclohexanediaminetetraacetic acid, imidinoacetic acid, N-hydroxymethylethylenediaminetriacetic acid or diethylenetriaminepentaacetic acid. The color developer may contain a competitive coupler, e.g., citrazinic acid, J-acid, H-acid, or a compensating developing agent, such as p-aminophenol, N-benzyl-p-aminophenol or 1-phenyl-3-pyrazolidone. The color developer preferably has a pH of from about 8 to 13. The temperature of the color developer is usually selected from 20 to 70°C, and preferably from 30 to 60°C. The photographic emulsion after color development is usually subjected to bleaching. Bleaching may be carried out simultaneously with fixing, or these two processes may be carried out separately. Examples of bleaching agents to be used include compounds of polyvalent metals, e.g., iron(III), cobalt(IV), chromium(VI) or copper(II), peracids, quinones or nitroso compounds. Specific examples of these bleaching agents are ferricyanides; bichromates; complex salts of iron(III) or cobalt(III) with aminopolycarboxylic acids, e.g., ethylenediaminetetraacetic acid, nitrilotriacetic acid or 1,3-diamino-2-propanoltetraacetic acid, or organic acids, e.g., citric acid, tartaric acid or malic acid; persulfates; permanganates or nitrophenol. Of these, potassium ferricyanide, sodium ethylenediaminetetraacetato ferrate(III) and ammonium ethylenediaminetetraacetato ferrate(III) are particularly useful. Aminopolycarboxylic acid iron(III) complex salts are useful in both an independent bleaching solution and a combined bleach-fix bath. The bleaching or bleach-fix bath can contain a bleach accelerating agent and other various additives as described in U.S. Patents 3,042,520 and 3,241,966, Japanese Patent Publication Nos. 8506/70 and 8836/70. A fixer to be used in the present invention contains from about 30 to 200 g/l of ammonium thiosulfate, sodium thiosulfate or pottasium thiosulfate as a fixing agent and can further contain a stabilizer, e.g., sulfites or metabisulfites; a hardener, e.g., potassium alum; a pH buffer, e.g., acetates, borates, phosphates or carbonates. The fixer has a pH of from 3 to 10, and preferably from 5 to 9. The present invention will now be illustrated in greater detail with reference to the following examples. EXAMPLE 1 A multi-layer color light-sensitive material was prepared by coating the following layers on a cellulose triacetate film support in the order listed. Each of the above layers additionally contained Gelatin Hardener C-15 and a surface active agent. The resulting sample was designated as Sample No. 101. The compounds used in Sample No. 101 are shown below. Sample Nos. 102 to 115 were prepared in the same manner as for Sample No. 101, except adding 0.5 x 10⁻⁵ mol/m² of the compound shown in Table 1 to each of the fourth and fifth layers. Each of Sample No. 101 to 115 thus prepared was exposed partly to red light and partly to white light (red + Green + blue light) through a step-wedge. The exposure amount of red light at the time of white light exposure and the exposure amount at the time of red light exposure were equal. The thus exposed material was subjected to color development processing at 38°C according to the procedure described below using the processing solutions described below. Upon comparing the cyan image obtained by red light exposure and that obtained by white light exposure, a difference in exposure amount (ΔlogE) at the area having a cyan density of 0.6 was measured. The larger the ΔlogE, the greater are the interimage effects. Separately, each Sample was exposed to light through a pattern for MTF (modulation transfer function) measurement, and submitted to the color development processing. The thus processed samples were measured with a microdensitometer, and MTF values of these samples were calculated. The "MTF value" is described in Theory of the Photographic Process, 4th edition, p. 604, Macmillan Publishing Co., Inc. (1977). Sharpness was represented by MTF value of 10 line/mm. Higher MTF value implies higher sharpness. The results thus obtained are shown in Table 1. It can be seen from Table 1 above that the light-sensitive materials according to the present invention are superior to the comparative samples in terms of interimage effects and sharpness. EXAMPLE 2 Sample No. 201 was prepared by coating the following layers on a cellulose triacetate film support in the order listed. First Layer : (Antihalation Layer) A gelatin layer containing black colloidal silver. Second Layer : (Gelatin Intermediate Layer) 2,5-Di-t-octylhydroquinone was dissolved in 100 ml of dibutyl phthalate and 100 ml of ethyl acetate, and the solution was dispersed in 1 kg of a 10% gelatin aqueous solution under stirring at a high speed to prepare 2 kg of an emulsion. The emulsion was mixed with 1 kg of a fine grain silver iodobromide emulsion (silver iodide: 1 mol%; grain size: 0.6 µm) which had not been chemically sensitized and 1.5 kg of a 10% aqueous gelatin solution, and then the mixture was coated to a dry thickness of 2 µm (silver coverage: 0.4 g/m²). Third Layer : (Low-Sensitive Red-Sensitive Emulsion Layer) In 100 ml of tricresyl phosphate and 100 ml of ethyl acetate was dissolved 100 g of a cyan coupler, 2-(heptafluorobutylamido)-5-[2'-(2'',4''-di-t-aminophenoxy)butylamido]-phenol, and the solution was dispersed in 1 kg of a 10% aqueous gelatin solution under stirring at high speed to obtain 500 g of an emulsion. The emulsion was mixed with 1 kg of a red-sensitive silver iodobromide emulsion (silver content: 70 g; gelatin content: 60 g; iodine content: 4 mol%), and the mixture was coated to a dry thickness of 1 µm (silver coverage: 0.5 g/m²). Fourth Layer : (High-Sensitive Red-Sensitive Emulsion Layer) In 100 ml of tricresyl phosphate and 100 ml of ethyl acetate was dissolved a cyan couples, 2-(heptafluorobutylamido)-5-[2'-(2'',4''-di-t-aminophenoxy)butylamido]-phenol, and the solution was dispersed in 1 kg of a 10% gelatin aqueous solution by stirring at a high speed to obtain 1 kg of an emulsion. The resulting emulsion was mixed with 1 kg of a red-sensitive silver iodobromide emulsion (silver content: 70 g; gelatin content: 60 g; iodide content: 2.5 mol%), and the composition was coated to a dry thickness of 2.5 µm (silver coverage: 0.7 g/m²). Fifth Layer : (Intermediate Layer) 100 ml of 2,5-di-t-octylhydroquinone was dissolved in 100 ml of dibutyl phthalate and 100 ml of ethyl acetate, and the solution was dispersed in 1 kg of a 10% gelatin aqueous solution by stirring at a high speed to prepare 1 kg of an emulsion. The emulsion was mixed with 1 kg of a 10% gelatin aqueous solution, and the resulting composition was coated to a dry thickness of 1 µm. Sixth Layer : (Low-Sensitive Green-Sensitive Emulsion Layer) An emulsion was prepared in the same manner as for the emulsion of the third layer, except for using a magenta coupler, 1-(2',4',6'-trichlorophenyl)-3-[3''-(2''',4'''-di-t-amylphenoxyacetamido)benzamido]-5-pyrazolone, in place of the cyan coupler. 300 g of the emulsion was mixed with 1 kg of a green-sensitive silver iodobromide emulsion (silver content: 70 g; gelatin content: 60 g; iodide content: 3 mol%), and the resulting composition was coated to a dry thickness of 1.3 µm (silver coverage: 0.7 g/m²). Seventh Layer : (High-Sensitive Green-Sensitive Emulsion Layer) An emulsion was prepared in the same manner as for the emulsion for the third layer except for using a magenta coupler, 1-(2',4',6'-trichlorophenyl)-3-[3''-(2''',4'''-di-t-amylphenoxyacetamido)benzamido]-5-pyrazolone, in place of the cyan coupler. 1 kg of this emulsion was mixed with 1 kg of a green-sensitive silver iodobromide emulsion (silver content: 73 g; gelatin content: 60 g; iodide content: 2.5 mol%), and the resulting composition was coated to a dry thickness of 3.5 µm (silver coverage: 0.8 g/m²). Eighth Layer : (Yellow Filter Layer) An emulsion containing yellow colloidal silver was coated to a dry thickness of 1 µm. Ninth Layer : (Low-Sensitive Blue-Sensitive Emulsion Layer) An emulsion was prepared in the same manner as for the emulsion of the third layer, except for using a yellow coupler, α-(pivaloyl)-α-(1-benzyl-5-ethoxy-3-hydantoinyl)-2-chloro-5-dodecyloxycarbonylacetanilide, in place of the cyan coupler. 1 kg of this emulsion was mixed with 1 kg of a blue-sensitive silver iodobromide emulsion (silver content: 70 g; gelatin content: 60 g; iodide content: 2.5 mol%), and the resulting composition was coated to a dry thickness of 1.5 µm (silver coverage: 0.6 g/m²) Tenth Layer : (High-Sensitive Blue-Sensitive Emulsion Layer) An emulsion was prepared in the same manner as for the emulsion of the third layer, except for using a yellow coupler, α-(pivaloyl)-α-(1-benzyl-5-ethoxy-3-hydantoinyl)-2-chloro-5-dodecyloxycarbonylacetanilide, in place Of the cyan coupler. 1 kg of this emulsion was mixed with 1 kg of a silver iodobromide emulsion (silver content: 70 g; gelatin content: 60 g; iodide content: 2.5 mol%), and the resulting composition was coated to a dry thickness of 3 µm (silver coverage: 1.1 g/m²). Eleventh Layer : (Second Protective Layer) 100 kg of a dispersion of Ultraviolet Absorbent C-1 as used in Example 1 was mixed with 1 kg of a 10% gelatin aqueous solution, and the resulting composition was coated to a dry thickness of 2 µm. Twelfth Layer : (First Protective Layer) A 10% gelatin aqueous solution containing polymethyl methacrylate particles having a diameter of 1.5 µm was coated to a dry thickness of 0.8 µm. Each of these layers further contained Gelatin Hardener C-15 and a surface active agent in addition to the above-described components. Sample Nos. 202 to 216 were prepared in the same manner as for Sample No.201 except that a compound shown in Table 2 was added to the layers indicated in Table 2 in an amount of 1 x 10⁻⁵ mol/m² per layer. Each of the resulting samples (Sample Nos. 201 to 216) was exposed partly to red light, green light, blue light or white light (red + green + blue light) through a step-wedge. The exposure amounts of the red light, green light and blue light in the white light exposure were equal to the exposure amounts in the red light exposure, green light exposure and blue light exposure, respectively. The exposed sample was then subjected to the following development processing using the following processing solutions. Upon comparing the cyan image obtained by red light exposure and that obtained by white light exposure, a difference in exposure amount (ΔlogE) at the area having a cyan density of 1.0 was measured. In the same manner, ΔlogE in the case of green light exposure and blue light exposure was also measured. The results obtained are shown in Table 2 below. It can be seen from the results of Table 2 that the interimage effects obtained by the present invention are far greater than those obtained in the comparative samples. EXAMPLE 3 Onto a cellulose triacetate film support were coated the following layers in the order listed, to prepare a black-and-white photographic light-sensitive material. First Layer : (Low-Sensitive Silver Halide Emulsion Layer) Potassium bromide, potassium iodide and silver nitrate were added to a gelatin aqueous solution while vigorously stirring to prepare a silver iodobromide emulsion (silver iodide content: 3 mol%) having a mean grain size of 0.6 µm. After desalting, the emulsion was subjected to gold-sulfur sensitization using chloroauric acid and sodium thiosulfate to the optimum degree to prepare Emulsion A. Emulsion A was coated to the support to provide a silver coverage of 1 g/m². Second Layer : (High-Sensitive Silver Halide Emulsion Layer) Emulsion B which was prepared in the same manner as for Emulsion A but having a mean grain size of 1.2 µm was coated to provide a silver coverage of 2.5 g/m². Third Layer : (Protective Layer) A layer containing 1.3 g/m² of gelatin and 0.05 g/m² of polymethyl methacrylate particles having a diameter of 1.5 µm. Each of the layers further contained Gelatin Hardener C-15, a surface active agent and sodium polystyrenesulfonate as a thickener in addition to the above-described components. The thus prepared material was designated as Sample No. 301. Sample Nos. 302 to 314 were prepared in the same manner as for Sample No. 301 except that each of the layers indicated in Table 3 further contained the compound indicated in Table 3 in an amount of 0.3 x 10⁻⁵ mol/m² per layer. Each sample was exposed to light through a pattern for granularity measurement or MTF measurement and then subjected to black-and-white development at 20°C for 7 minutes using the following processing solutions. The thus processed samples were examined for RMS granularity through the density measurement using a microdensitometer, according to Photographic Science and Engineering, vol. 19, p. 235 (1975). That is, graininess (RMS granularity) of the resulting image was determined by scanning the image with a microdensitometer and multiplying a standard deviation in density variation by 1000. The smaller the RMS granularity the better is the graininess. Further, sharpness of the image was evaluated in terms of the MTF value as in Example 1. These results are shown in Table 3. As is shown in Table 3, the light-sensitive materials according to the present invention have improved graininess and sharpness as compared with the comparative samples.

Claims: A silver halide photographic material comprising at least one thiadiazole compound characterized in that said thiadiazole compound is represented by formula (I) or formula (II) wherein R¹ represents a straight or branched chain alkylene, alkenylene or aralkylene group, or an arylene group; R² represents a hydrogen atom, or a substituted or unsubstituted alkyl, aryl, alkenyl or aralkyl group; X represents a hydrogen atom, an alkali metal atom, an ammonium group, or a precursor capable of providing a hydrogen atom or an alkali metal under an alkaline condition; Z¹ represents a quaternary ammonium group, an alkoxy group, an alkylthio group, an arylthio group, a heterocyclic oxy group, a heterocyclic thio group, a carbamoyl group, a sulfamoyl group, an acyloxy group, a ureido group, a thioureido group, or a sulfonyloxy group; Z² represents a quaternary ammonium group, an alkoxy group, an alkylthio group, an arylthio group, a heterocyclic oxy group, a heterocyclic thio group, a carbamoyl group, a sulfamoyl group, an acyloxy group, a ureido group, a thioureido group, a sulfonyloxy group, a substituted or unsubstituted amino group or a salt thereof, an aryloxy group, a heterocyclic group, or a cyano group, and n represents 0 or 1. The silver halide photographic material of claim 1, wherein R¹ represents an alkylene group. The silver halide photographic material of claim 1, wherein R² represent a hydrogen atom, or an alkyl group. The silver halide photographic material of claim 1, wherein Z¹ represents a quaternary ammonium group, a carbamoyl group, or a ureido group; and Z² represents a quaternary ammonium group, a carbamoyl group, a ureido group, and amino group, or a heterocyclic group. The silver halide photographic material of claim 1, wherein n in formula (I) represents 1. The silver halide photographic material of claim 1, wherein said compound is present in an amount of from 10⁻¹ to 10⁻⁵ mols per mol of silver halide in the layer in which the compound is incorporated or in layers adjacent thereto. The silver halide photographic light-sensitive material of claim 1, wherein said compound is present in an amount of from 3 x 10⁻² to 3 x 10⁻⁴ mols per mol of silver halide in the layer in which the compound is incorporated or in layers adjacent thereto. The silver halide photographic material of claim 1, wherein said material is a multi-layer color photographic light-sensitive material comprising at least one silver halide emulsion layer and said compound is present in at least one silver halide emulsion layer or a layer adjacent thereto. The silver halide photographic material of claim 1, wherein said material is a black-and-white photographic light-sensitive material comprising at least one silver halide emulsion layer, and said compound is present in at least one silver halide emulsion layer or a layer adjacent thereto.

Inventors: DEGUCHI, NAOYASU, KOJIMA, TETSURO, MIYAZAKI, HIDEO, NAKAMURA, KOKI, OHNO, SHIGERU
Applicants: FUJI PHOTO FILM CO., LTD.
Application year: 1985
Main classification: G03C7
IPC codes: C07D285, G03C7