Silver halide color photographic light-sensitive material
FIELD OF THE INVENTION 
     The present invention relates to a silver halide color photographic light-sensitive material containing a novel compound which is capable of rendering a photographically useful group utilizable during development processing. 
     BACKGROUND OF THE INVENTION 
     It is known that upon color development of silver halide color photographic materials, the oxidation products of aromatic primary amine color developing agents react with couplers to form indophenol, indoaniline, indamine, azomethine, phenoxazine, phenazine and similar dyes, thereby forming color images. In this system, color reproduction is usually accomplished by the subtractive color process; silver halide emulsions selectively sensitive to blue, green and red, and yellow, magenta and cyan color image forming agents in a complementary relation therewith are used. For example, acylacetanilide or dibenzoylmethane type couplers are used to form yellow color images; pyrazolone, pyrazolobenzimidazole, cyanoacetophenone or indazolone type couplers are mainly used to form magenta color images; and phenol type couplers, such as phenols and naphthols, are mainly used to form cyan color images. 
     It is also known that couplers are used not only to form dye images as described above but also for the purpose of releasing photographically useful groups. For example, U.S. Pat. Nos. 3,227,554 and 3,148,062, and Journal of the American Chemical Society, Vol. 72, page 1533 (1950) disclose couplers which release a development inhibitor or a dye from the coupling position thereof on reacting with the oxidation products of color developing agents. 
     Further, U.S. Pat. No. 3,705,801 discloses couplers which are capable of releasing a bleach inhibitor from the coupling position thereof after the reaction of the couplers with the oxidation products of the developing agents. More recently, Japanese Patent Application (OPI) No. 150845/82 (the term &#34;OPI&#34; as used herein refers to a &#34;published unexamined Japanese patent application&#34;) discloses couplers which release a fogging agent from the coupling position thereof after the reaction of the couplers with the oxidation products of the developing agents. 
     Moreover, compounds which do not form dyes but release a photographically useful group upon the reaction with the oxidation products of the developing agents have also been known. For example, U.S. Pat. No. 3,930,863 discloses hydroquinones which release a development inhibitor. 
     As is well known from the above-described patent specifications, compounds releasing a photographically useful groups are used for purposes such as improvement in color reproducibility, improvement in graininess, improvement in sharpness, or increase of sensitivity. 
     It is common knowledge in the photographic art that a technique to control the rate of releasing a photographically useful group and the rate of diffusion into an emulsion is more important than a technique to control the photographic function of the photographically useful group in the compounds capable of releasing a photographically useful group. It is also disclosed that as the diffusibility of the development inhibitors released increases, the sharpness is more improved as described in Japanese Patent Application (OPI) No. 36249/84. As an example of such techniques, couplers which release a photographically useful group having a timing group are proposed in U.S. Pat. Nos. 4,248,962 and 4,409,323, etc. These known couplers have good properties to some extent since the increase in the rate of coupling with these couplers is recognized in comparison with couplers wherein the photographically useful group is directly connected to the coupling position (for example, couplers as described in U.S. Pat. No. 3,227,554, etc.). 
     However, with these compounds the degree of diffusion of the photographically useful group into an emulsion is low and further improvement of the photographic properties has been desired. Furthermore, known couplers having a timing group have a problem in stability thereof during preservation of films containing the couplers after coating and the couplers are disadvantageous in that their function is decreased or desensitization or formation of fog is accompanied by decomposition of the couplers. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to solve the above-described problems, and more specifically to provide a color photographic light-sensitive material which has good stability during preservation and either provides a color image having good image qualities such as sharpness, graininess and color reproducibility, etc., or has high sensitivity by using a novel compound which is chemically stable and capable of releasing a photographically useful group at the desired rate, diffusibility of the photographically useful group released is large and the function area of the photographically useful group released can be effectively controlled. 
     Other objects of the present invention will become apparent from the following detailed description and examples. 
     These objects of the present invention have been accomplished by a silver halide color photographic light-sensitive material comprising a support having thereon at least one silver halide emulsion layer, the color photographic light-sensitive material containing a compound capable of releasing a group represented by the general formula (I) described below upon the reaction with the oxidation product of a developing agent: ##STR4## wherein W represents an oxygen atom, a sulfur atom or a group ##STR5## (wherein R represents a hydrogen atom or an organic residue); X represents an electron withdrawing substituent; Y represents a hydrogen atom or a substituent; PUG represents a photographically useful group or a precursor thereof; X and Y each represents a divalent group and may be connected to each other to form a cyclic structure; and when W represents the group ##STR6## and R represents an organic residue, R and X or R and Y each represents a divalent group and may be connected to each other to form a cyclic structure. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The compounds according to the present invention can eliminate the above-described defects and further have excellent photographic properties. 
     The group represented by the general formula (I) is connected to a coupler residue or a hydroquinone residue. When the group is connected to a coupler residue, it is usual to connect it to the coupling position thereof. However, the effects of the present invention are equally obtained in cases wherein the group represented by the general formula (I) is cleaved as a result of the coupling reaction, even when the group is not connected to the coupling position directly. For example, there is the case in which the group represented by the general formula (I) is employed in place of the PUG in the compounds described in Japanese Patent Application (OPI) No. 209740/83. Moreover, the coupler residues employed may be those of bis type couplers or polymer couplers. 
     The compound having the group represented by the general formula (I) releases an anion (a) described below upon the reaction with the oxidation product of a developing agent. The anion (a) diffuses in an emulsion and at the same time releases PUG through the reaction schematically illustrated as follows: ##STR7## wherein W, X, Y and PUG each has the same meaning as defined in the general formula (I). 
     The groups represented by X and Y are present for the purpose of controlling the rate of cleavation of the group represented by the general formula (I) and for the purpose of controlling stability of anion species of the compound (a). In particular, the electron withdrawing group represented by X is used in order to increase stability of the anion and thereby diffusibility of the compound (a) is effectively controlled. 
     As the electron withdrawing substituent represented by X, any group which is more electron withdrawing than a hydrogen atom can be employed. Examples of the electron withdrawing groups include an acyl group (for example, an acetyl group, a benzoyl group, etc.), an alkoxycarbonyl group (for example, an ethoxycarbonyl group, a methoxycarbonyl group, etc.), an aryloxycarbonyl group (for example, a phenoxycarbonyl group, a 4-chlorophenoxycarbonyl group, etc.), a carbamoyl group (for example, a carbamoyl group, an N-ethylcarbamoyl group, etc.), a sulfonyl group (for example, a methanesulfonyl group, a benzenesulfonyl group, etc.), a sulfamoyl group (for example, a sulfamoyl group, an N-methylsulfamoyl group, an N-phenylsulfamoyl group, etc.), a sulfinyl group (for example, a methylsulfinyl group, a benzenesulfinyl group, etc.), a cyano group, a nitro group, a nitroso group, a carboxy group, a sulfo group, a trifluoromethyl group or an aliphatic group having any of the substituents described above through a methylene group or an ethylene group. 
     In the general formula (I), preferred examples of the substituents represented by Y include the substituents as illustrated for X above, an aliphatic group, an aromatic group or a heterocyclic group. When Y represents an aliphatic group, it may be any of substituted or unsubstituted, saturated or unsaturated, straight chain, branched chain or cyclic groups and contain from 1 to 15, preferably from 1 to 5 carbon atoms. Specific examples of the aliphatic group include a methyl group, an ethyl group, an isopropyl group, a methoxyethyl group, a 2-chloroethyl group, a cyclohexyl group, a 1,1-dimethylethyl group, and an allyl group, etc. 
     When Y represents an aromatic group, it is preferably a substituted or unsubstituted phenyl group. Specific examples of the aromatic group include a phenyl group, a 2-chlorophenyl group, a 4-methoxyphenyl group, a 4-carboxyphenyl group, a 4-nitrophenyl group, a 4-methanesulfonylphenyl group, and a 4-chlorophenyl group, etc. 
     When Y represents a heterocyclic group, it is preferably a 3-membered to 7-membered heterocyclic group containing a nitrogen atom, a sulfur atom or an oxygen atom as a hetero atom. Specific examples of the heterocyclic group include a 2-pyridyl group, a 2-furyl group, a 4-imidazolyl group, a 4-pyrazolyl group, and a tetrahydrothiophen-1,1-dioxido-2-yl group, etc. 
     Preferred examples of the organic residue represented by R in the group of ##STR8## which is represented by W in the general formula (I) include an acyl group (for example, an acetyl group, a benzoyl group, etc.), an alkoxycarbonyl group (for example, an ethoxycarbonyl group, a methoxycarbonyl group, etc.), an aryloxycarbonyl group (for example, a phenoxycarbonyl group, a 4-chlorophenoxycarbonyl group, etc.), a carbamoyl group (for example, a carbamoyl group, an N-ethylcarbamoyl group, etc.), a sulfonyl group (for example, a methanesulfonyl group, a benzenesulfonyl group, etc.), a sulfamoyl group (for example, a sulfamoyl group, an N-methylsulfamoyl group, an N-phenylsulfamoyl group, etc.), a sulfinyl group (for example, a methylsulfinyl group, a benzenesulfinyl group, etc.), a cyano group, a trifluoromethyl group, an aryl group (for example, a phenyl group, a 4-chlorophenyl group, etc.), an aliphatic group (for example, a methyl group, an isopropyl group, etc.), a heterocyclic group (for example, a pyridyl group, a 1,2,4-triazol-3-yl group, etc.), and a hydroxy group, etc. When the above-described substituents represented by R include alkyl moieties, they may be any of substituted or unsubstituted, saturated or unsaturated, straight chain, branched chain or cyclic groups and contain from 1 to 15, preferably from 1 to 5, carbon atoms. 
     In the general formula (I), the group represented by PUG include, in detail, groups containing a development inhibitor, a development accelerator, a fogging agent, a dye, a developing agent, a coupler, a silver removing accelerator, a silver halide solvent, a competing compound and a silver removing inhibitor, etc. 
     An appropriate selection of PUG can be made depending on the purpose for which the compound is employed. Further, the photographic function can be controlled at the desired rate depending on the purpose. The control of the rate at which the photographic function is exhibited is possible by the selection of the groups represented by X and Y in the general formula (I). Moreover, the photographic function of PUG can be controlled to a desired property depending on the purpose. This can be carried out by selecting the substituent on PUG, for example, whether the substituent is electron attractive or electron donative or whether it is hydrophilic or hydrophobic. 
     Preferred examples of PUG include the following general formulae (P-1) to (P-9). ##STR9## wherein G 1  represents a hydrogen atom, a halogen atom, an alkyl group (for example, a methyl group, an ethyl group, etc.), an acylamino group (for example, a benzamido group, a caproamido group, etc.), an alkoxy group (for example, a butoxy group, a benzyloxy group, etc.), a sulfonamido group (for example, an octanesulfonamido group, a p-toluenesulfonamido group, etc.), an aryl group (for example, a phenyl group, a 4-chlorophenyl group, etc.), an alkylthio group (for example, a methylthio group, a butylthio group, etc.), an alkylamino group (for example, a cyclohexylamino group, etc.), an anilino group (for example, an anilino group, a 4-methoxycarbonylanilino group, etc.), an amino group, an alkoxycarbonyl group (for example, a methoxycarbonyl group, a butoxycarbonyl group, etc.), an acyloxy group (for example, an acetyloxy group, a butanoyloxy group, a benzoyloxy group, etc.), a nitro group, a cyano group, a sulfonyl group (for example, a butanesulfonyl group, a benzenesulfonyl group, etc.), an aryloxy group (for example, a phenoxy group, a naphthyloxy group, etc.), a hydroxy group, a thioamido group (for example, a butanethioamido group, a benzenethiocarbonamido group, etc.), a carbamoyl group (for example, a carbamoyl group, an N-arylcarbamoyl group, etc.), a sulfamoyl group (for example, a sulfamoyl group, an N-arylsulfamoyl group, etc.), a carboxy group, a ureido group (for example, a ureido group, an N-ethylureido group, etc.) or an aryloxycarbonyl group (for example, a phenoxycarbonyl group, a 4-methoxyphenoxycarbonyl group, etc.); G 2  represents a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, etc.) or an aryl group (for example, a phenyl group, a naphthyl group, etc.); G 3  represents a hydroxy group, a sulfonamido group (for example, a butanesulfonamido group, a benzenesulfonamido group, etc.), an amino group, an alkylamino group (for example, an ethylamino group, a cyclohexylamino group, etc.), an anilino group (for example, an anilino group, a 4-methylanilino group, etc.) or a hydrogen atom, two G 3  s in the general formula (P-5) may be the same or different provided that both G 3  s are not hydrogen atoms at the same time; G 4  represents an aryl group (for example, a phenyl group, a naphthyl group, etc.); G 5  represents a hydrogen atom, a heterocyclic thio group (for example, a group represented by the general formula (P-3) or (P-4), etc.) or a nitrogen-containing heterocyclic group condensed with a benzene ring (for example, a group represented by the general formula (P-1) or (P-2), etc.); f represents an integer of 1 or 2, when f is 2, two G 1  s may be the same or different and two G 2  s may be the same or different; V 1  represents a nitrogen atom or a group of ##STR10## (wherein G 1  has the same meaning as defined above and may be the same or different from other G 1  s present in the molecule thereof); and V 2  represents an oxygen atom, a sulfur atom or a group of ##STR11## (wherein G 2  has the same meaning as defined above), and in the general formula (P-4) when V 1  represents a group of ##STR12## two G 1  s may be combined to form a condensed benzene ring (for example, a benzimidazolythio group when V 2  represents a group of --NH--, a benzoxazolylthio group when V 2  represents an oxygen atom, etc.). 
     When the groups represented by G 1 , G 2 , G 3 , G 4  or G 5  in the general formula (P-1), (P-2), (P-3), (P-4), (P-5), (P-6), (P-7), (P-8) or (P-9) contain alkyl moieties, said alkyl moieties may be any of substituted or unsubstituted, straight chain, branched chain or cyclic, saturated or unsaturated alkyl groups and contain from 1 to 22 carbon atoms, preferably from 1 to 10 carbon atoms. Further, when the groups represented by G 1 , G 2 , G 3 , G 4  or G 5  contain aryl moieties, said aryl moieties may be any of substituted or unsubstituted aryl group and contain from 6 to 10 carbon atoms, and are preferably substituted or unsubstituted phenyl groups. 
     The groups represented by the general formulae (P-1), (P-2), (P-3) and (P-4) are moieties of development inhibitors. The compounds which release these groups are generally called as DIR compounds. In comparison with known DIR compounds, however, the DIR compounds according to the present invention can effectively control the area in which development inhibitors function and further have sufficient stability. As a result, color photographic images having excellent properties with graininess, color reproducibility due to interimage effects and particularly sharpness can be obtained. 
     The groups represented by the general formulae (P-5), (P-6) and (P-7) are moities of developing agents and have a reducing function. Various effects of these groups on photographic properties are known. For example, when they reduce the oxidation products of developing agents, they are designated competing compounds and are effective for improvement in graininess or sharpness, and when they reduce silver halides or when they are employed as an auxiliary developing agent, sensitivity is increased. 
     The groups represented by the general formulae (P-8) and (P-9) are examples of coupler moieties. They function as competing couplers and are particularly preferred for improvement in graininess. 
     With the groups represented by the general formulae (P-5), (P-8) and (P-9) wherein G 5  represents a development inhibitor moiety such as a heterocyclic thio group, etc., the inhibiting action is further added and thus the function as a DIR coupler can be effectively added. 
     Preferred compounds of the compounds which can be used in the present invention can be represented by the following general formula (Ia): ##STR13## wherein A represents a coupler residue; and W, X, Y and PUG each has the same meaning as defined in the general formula (I). 
     Particularly preferred compounds of the compounds which can be used in the present invention can be represented by the following general formula (Ib), (Ic) or (Id): ##STR14## wherein A represents a coupler residue; PUG represents a photographically useful group; X 1  represents an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group (including substituted or unsubstituted carbamoyl group at N-position thereof), a sulfamoyl group (including substituted or unsubstituted sulfamoyl group at N-position thereof), or a sulfonyl group; X 2  represents a group ##STR15## or a group --SO 2  --; and Z represents an organic residue to form a 5- or 6-membered ring together with the group ##STR16## Preferred examples of Z include a group --CH 2  CH 2  --, a group ##STR17## a group ##STR18## and a group ##STR19## wherein Y 1  represents a hydrogen atom, an aliphatic group, an aromatic group, an acyl group, or a sulfonyl group; Y 2  and Y 3  each represents a hydrogen atom, an aliphatic group, an aromatic group, or a halogen atom. 
     Further, the effects of the present invention are particularly exhibited when A in the general formula (Ia) represents a coupler residue represented by the general formula (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI) or (XII) described below. These couplers are preferred because of their high coupling rates. ##STR20## 
     In the above-described formulae, a free bond attached to the coupling position indicates a position to which the group represented by the general formula (I) is connected. When R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10  or R 11  in the above-described formulae contains a diffusion resistant group, it is selected so that the total number of carbon atoms included therein is from 8  to 32 and preferably from 10 to 22. On the other hand, when it does not contain a diffusion resistant group, the total number of carbon atoms included therein is preferably not more than 15. 
     In the following, R 1  to R 11 , l, m and p in the above-described general formulae (II) to (XII) are explained. 
     In the above-described formulae, R 1  represents an aliphatic group, an aromatic group, an alkoxy group or a heterocyclic group; and R 2  and R 3  each represents an aromatic group or a heterocyclic group. 
     The aliphatic group represented by R 1  is preferably an aliphatic group (especially an alkyl group) containing from 1 to 22 carbon atoms, and may have substituents or not, and further, may have a chain form or a cyclic form. Preferable substituents therefor include an alkoxy group, an aryloxy group, an amino group, an acylamino group, a halogen atom, etc., which each may further have a substituent(s). Specific examples of aliphatic groups useful for R 1  include an isopropyl group, an isobutyl group, a tert-butyl group, an isoamyl group, a tert-amyl group, a 1,1-dimethylbutyl group, a 1,1-dimethylhexyl group, a 1,1-diethylhexyl group, a dodecyl group, a hexadecyl group, an octadecyl group, a cyclohexyl group, a 2-methoxyisopropyl group, a 2-phenoxyisopropyl group, a 2-p-tert-butylphenoxyisopropyl group, an α-aminoisopropyl group, an α-(diethylamino)isopropyl group, an α-(succinimido)isopropyl group, an α-(phthalimido)isopropyl group, an α-(benzenesulfonamido)isopropyl group, etc. 
     In the case that R 1 , R 2  or R 3  represents an aromatic group (especially a phenyl group), it may have a substituent. Such an aryl group as a phenyl group, etc., may be substituted with an alkyl group, an alkenyl group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonylamino group, an aliphatic amido group, an alkylsulfamoyl group, an alkylsulfonamido group, an alkylureido group, an alkyl-substituted succinimido group, etc., each containing 32 or less carbon atoms. The alkyl group therein may include an alkyl group which contains an aromatic group such as phenylene in its main chain. Further, a phenyl group represented by R 1 , R 2  or R 3  may be substituted with an aryloxy group, an aryloxycarbonyl group, an arylcarbamoyl group, an arylamido group, an arylsulfamoyl group, an arylsulfonamido group, an arylureido group, etc., the aryl moiety of which groups each may be substituted with one or more alkyl groups wherein the number of carbon atoms is from 1 to 22 in total. 
     Furthermore, a phenyl group represented by R 1 , R 2  or R 3  may be substituted with an amino group which includes an amino group substituted with a lower alkyl group having from 1 to 6 carbon atoms, a hydroxy group, a carboxy group, a sulfo group, a nitro group, a cyano group, a thiocyano group or a halogen atom. 
     In addition, R 1 , R 2  or R 3  may represent a substituent formed by condensing a phenyl group and another ring to form, for example, a naphthyl group, a quinolyl group, an isoquinolyl group, a chromanyl group, a coumaranyl group, a tetrahydronaphthyl group, etc. These substituents may further have substituents in themselves. 
     In the case that R 1  represents an alkoxy group, the alkyl moiety thereof represents a straight chain or branched chain alkyl group having from 1 to 32 carbon atoms, preferably from 1 to 22 carbon atoms, an alkenyl group, a cyclic alkyl group or a cyclic alkenyl group, which each may be substituted with a halogen atom, an aryl group, an alkoxy group, etc. 
     In the case that R 1 , R 2  or R 3  represents a heterocyclic group, the heterocyclic group is connected to the carbon atom of the carbonyl group of the acyl moiety or the nitrogen atom of the amido moiety of an α-acylacetamide compound through one of the carbon atoms forming the ring. Examples of such heterocyclic rings include thiophene, furan, pyran, pyrrole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, imidazole, thiazole, oxazole, triazine, thiadiazine, oxazine, etc. These rings may further have substituents on the individual rings. 
     In the above-described formula, R 5  represents a straight chain or branched chain alkyl group having from 1 to 32 carbon atoms, preferably from 1 to 22 carbon atoms (e.g., a methyl group, an isopropyl group, a tertbutyl group, a hexyl group, a dodecyl group, etc.), an alkenyl group (e.g., an allyl group, etc.), a cyclic alkyl group (e.g., a cyclopentyl group, a cyclohexyl group, a norbornyl group, etc.), an aralkyl group (e.g., a benzyl group, a β-phenylethyl group, etc.), a cyclic alkenyl group (e.g., a cyclopentenyl group, a cyclohexenyl group, etc.), etc., which groups each may be substituted with a halogen atom, a nitro group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, a carboxy group, an alkylthiocarbonyl group, an arylthiocarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfo group, a sulfamoyl group, a carbamoyl group, an acylamino group, a diacylamino group, a ureido group, a urethane group, a thiourethane group, a sulfonamido group, a heterocyclic group, an arylsulfonyl group, an alkylsulfonyl group, an arylthio group, an alkylthio group, an alkylamino group, a dialkylamino group, an anilino group, an N-arylanilino group, an N-alkylanilino group, an N-acylanilino group, a hydroxy group, a mercapto group, etc. 
     R 5  may further represent an aryl group (e.g., a phenyl group, an α- or β-naphthyl group, etc.). The aryl group may have one or more substituents. Specific examples of the substituents include an alkyl group, an alkenyl group, a cyclic alkyl group, an aralkyl group, a cyclic alkenyl group, a halogen atom, a nitro group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, a carboxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfo group, a sulfamoyl group, a carbamoyl group, an acylamino group, a diacylamino group, a ureido group, a urethane group, a sulfonamido group, a heterocyclic group, an arylsulfonyl group, an alkylsulfonyl group, an arylthio group, an alkylthio group, an alkylamino group, a dialkylamino group, an anilino group, an N-alkylanilino group, an N-arylanilino group, an N-acylanilino group, a hydroxy group, a mercapto group, etc. A more preferable group for R 5  is a phenyl group which is substituted with an alkyl group, an alkoxy group, a halogen atom, etc., at least at one of the o-positions, because it is effective to restrain coloration of couplers remaining in film layers due to light or heat. 
     Furthermore, R 5  may represent a heterocyclic group (e.g., a 5-membered or 6-membered heterocyclic ring containing as a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom, or a condensed ring thereof, with specific examples including a pyridyl group, a quinolyl group, a furyl group, a benzothiazolyl group, an oxazolyl group, an imidazolyl group, a naphthoxazolyl group, etc.), a heterocyclic group substituted with one or more substituents as defined for the above-described aryl group, an alphatic acyl group, an aromatic acyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylcarbamoyl group, an arylcarbamoyl group, an alkylthiocarbamoyl group or an arylthiocarbamoyl group. 
     In the above-described general formulae, R 4  represents a hydrogen atom, a straight chain or branched chain alkyl group having from 1 to 32 carbon atoms, preferably from 1 to 22 carbon atoms, an alkenyl group, a cyclic alkyl group, an aralkyl group or a cyclic alkenyl group (which each may have one or more substituents as defined for the above-described substituent R 5 ), an aryl group or a heterocyclic group (which each also may have one or more substituents as defined for the above-described substituent R 5 ), an alkoxycarbonyl group (e.g., a methoxycarbonyl group, an ethoxycarbonyl group, a stearyloxycarbonyl group, etc.), an aryloxycarbonyl group (e.g., a phenoxycarbonyl group, a naphthoxycarbonyl group, etc.), an aralkyloxycarbonyl group (e.g., a benzyloxycarbonyl group, etc.), an alkoxy group (e.g., a methoxy group, an ethoxy group, a heptadecyloxy group, etc.), an aryloxy group (e.g., a phenoxy group, a tolyloxy group, etc.), an alkylthio group (e.g., an ethylthio group, a dodecylthio group, etc.), an arylthio group (e.g., a phenylthio group, an α-naphthylthio group, etc.), a carboxy group, an acylamino group (e.g., an acetylamino group, a 3-[(2,4-di-tert-amylphenoxy)acetamido]benzamido group, etc.), a diacylamino group, an N-alkylacylamino group (e.g., an N-methylpropionamido group, etc.), an N-arylacylamino group (e.g., an N-phenylacetamido group, etc.), a ureido group (e.g., a ureido group, an N-arylureido group, an N-alkylureido group, etc.), a urethane group, a thiourethane group, an arylamino group (e.g., a phenylamino group, an N-methylanilino group, a diphenylamino group, an N-acetylanilino group, a 2-chloro-5-tetradecanamidoanilino group, etc.), an alkylamino group (e.g., an n-butylamino group, a methylamino group, a cyclohexylamino group, etc.), a cycloamino group (e.g., a piperidino group, a pyrrolidino group, etc.), a heterocyclic amino group (e.g., a 4-pyridylamino group, a 2-benzoxazolylamino group, etc.), an alkylcarbonyl group (e.g., a methylcarbonyl group, etc.), an arylcarbonyl group (e.g., a phenylcarbonyl group, etc.), a sulfonamido group (e.g., an alkylsulfonamido group, an arylsulfonamido group, etc.), a carbamoyl group (e.g., an ethylcarbamoyl group, a dimethylcarbamoyl group, an N-methylphenylcarbamoyl group, an N-phenylcarbamoyl group, etc.), a sulfamoyl group (e.g., an N-alkylsulfamoyl group, an N,N-dialkylsulfamoyl group, an N-arylsulfamoyl group, an N-alkyl-N-arylsulfamoyl group, an N,N-diarylsulfamoyl group, etc.), a cyano group, a hydroxy group, a mercapto group, a halogen atom or a sulfo group. 
     In the above-described formulae, R 6  represents a hydrogen atom, or a straight chain or branched chain alkyl group having from 1 to 32 carbon atoms, preferably from 1 to 22 carbon atoms, an alkenyl group, a cyclic alkyl group, an aralkyl group or a cyclic alkenyl group, which each may have one or more substituents as defined for the above-described substituent R 5 . 
     Further, R 6  may represent an aryl group or a heterocyclic group, which each may have one or more substituents as defined for the above-described substituent R 5 . 
     Furthermore, R 6  may represent a cyano group, an alkoxy group, an aryloxy group, a halogen atom, a carboxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a sulfo group, a sulfamoyl group, a carbamoyl group, an acylamino group, a diacylamino group, a ureido group, a urethane group, a sulfonamido group, an arylsulfonyl group, an alkylsulfonyl group, an arylthio group, an alkylthio group, an alkylamino group, a dialkylamino group, an anilino group, an N-arylanilino group, an N-alkylanilino group, an N-acylanilino group, a hydroxy group or a mercapto group. 
     In the above-described formulae, R 7 , R 8  and R 9  each represents a group which has been employed in conventional 4-equivalent type phenol or α-naphthol couplers. Specifically, R 7  represents a hydrogen atom, a halogen atom, an alkoxycarbonylamino group, an aliphatic hydrocarbon residue, an N-arylureido group, an acylamino group, an --O--R 12  group or an --S--R 12  group (wherein R 12  is an aliphatic hydrocarbon residue). When two or more of R 7  s are present in one molecule, they may be different from each other. The above-described aliphatic hydrocarbon residues include those having substituents. In the case that these substituents include an aryl group, the aryl group may have one or more substituents as defined for the above-described substituent R 5 . 
     R 8  and R 9  each represents an aliphatic hydrocarbon residue, an aryl group or a heterocyclic group. One of them may be a hydrogen atom. The above-described groups for R 8  and R 9  may further have certain substituents. Furthermore, R 8  and R 9  may combine with each other and form a nitrogen-containing heterocyclic nucleus. More specifically, the above-described aliphatic hydrocarbon residue includes both saturated and unsaturated residues, wherein each may have a straight chain form, a branched chain form or a cyclic form. Preferred examples thereof include an alkyl group (e.g., a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, an isobutyl group, a dodecyl group, an octadecyl group, a cyclobutyl group, a cyclohexyl group, etc.) and an alkenyl group (e.g., an allyl group, an octenyl group, etc.). The above-described aryl group includes a phenyl group, a naphthyl group, etc. Representatives of the above-described heterocyclic groups include a pyridinyl group, a quinolyl group, a thienyl group, a piperidyl group, an imidazolyl group, etc. These aliphatic hydrocarbon residues, aryl groups and heterocyclic groups each may be substituted with a halogen atom, a nitro group, a hydroxy group, a carboxy group, an amino group, a substituted amino group, a sulfo group, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an arylthio group, an arylazo group, an acylamino group, a carbamoyl group, an ester group, an acyl group, an acyloxy group, a sulfonamido group, a sulfamoyl group, a sulfonyl group, a morpholino group, etc. 
     In the above-described formulae, l represents an integer of 1 to 4, m represents an integer of 1 to 3, and p represents an integer of 1 to 5. 
     In the above-described formula, R 10  represents an arylcarbonyl group, an alkanoyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, an arylcarbamoyl group, an alkanecarbamoyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, an alkoxycarbonyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, or an aryloxycarbonyl group, which each may be substituted. Examples of the substituents include an alkoxy group, an alkoxycarbonyl group, an acylamino group, an alkylsulfamoyl group, an alkylsulfonamido group, an alkylsuccinimido group, a halogen atom, a nitro group, a carboxy group, a nitrile group, an alkyl group, an aryl group, etc. 
     In the above-described formula, R 11  represents an arylcarbonyl group, an alkanoyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, an arylcarbamoyl group, an alkanecarbamoyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, an alkoxycarbonyl group having from 2 to 32 carbon atoms, preferably from 2 to 22 carbon atoms, an aryloxycarbonyl group, an alkanesulfonyl group having from 1 to 32 carbon atoms, preferably from 1 to 22 carbon atoms, an arylsulfonyl group, an aryl group or a 5-membered or 6-membered heterocyclic group (containing as a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom, with specific examples including a triazolyl group, an imidazolyl group, a phthalimido group, a succinimido group, a furyl group, a pyridyl group, a benzotriazolyl group, etc.), which each may have one or more substituents as defined for the above-described substituent R 10 . 
     The compounds capable of releasing a group represented by the general formula (I) upon the reaction with the oxidation product of a developing agent according to the present invention are preferably employed together with other conventional couplers. They can be used in a range from 0.1 mol% to 100 mol%, preferably from 1 mol% to 30 mol% based on the main couplers used (i.e., conventional color couplers). The main couplers (conventional color couplers) are generally used in a range of from about 0.5×10 -4  to 5.0×10 -3  mol/m 2 . 
     Specific examples of the compounds capable of releasing a group represented by the general formula (I) upon the reaction with the oxidation product of a developing agent used in the present invention are set forth below, but the present invention should not be construed as being limited thereto. ##STR21## 
    
    
     Typical examples of syntheses of the compounds according to the present invention are specifically shown below. 
     SYNTHESIS EXAMPLE 1 
     Synthesis of Compound (1) 
     Compound (1) was synthesized according to the following synthesis route: ##STR22## 
     Step (1): 
     To a mixture of 95 g (0.53 mol) of 1-phenyl-5-mercaptotetrazole, 300 ml of ethyl acetate and 200 ml of acetonitrile was added 91 g (0.65 mol) of bromoacetic acid and then 74 ml (0.53 mol) of triethylamine was added dropwise thereto at room temperature with stirring over a period of 15 minutes. After 2 hours, the white crystals thus precipitated were removed off by filtration and washed with 50 ml of ethyl acetate. The resulting filtrate was concentrated under a reduced pressure and to the residue was added 150 ml of ether and the mixture was allowed to stand overnight. The crystals thus precipitated were collected by filtration to obtain 112 g of Compound (i) as white crystals. 
     Step (2): 
     95.2 g (0.4 mol) of the crystals of Compound (i) obtained in Step (1) were dissolved in 200 ml of thionyl chloride and the solution was mildly refluxed for 1 hour. After cooling to room temperature, 32 ml (0.4 mol) of sulfuryl chloride was added thereto over a period of 30 minutes. After 1 hour the mixture was heated to 50° to 60° C. and further reacted for 2 hours. The excessive reagents were distilled off under a reduced pressure and to the residue was added dropwise 100 ml of desiccated ethanol at room temperature over a period of 30 minutes. After the completion of the dropwise addition, the mixture was reacted at 40° to 45° C. for 2 hours. The reaction solution was concentrated using an evaporator, the residue was dissolved in 500 ml of ethyl acetate. The ethyl acetate solution was washed twice with each 200 ml of water and dried with anhydrous sodium sulfate. 23 g of active carbon was added to the solution, the mixture was stirred at room temperature for 30 minutes and filtered to remove active carbon. The filtrate was concentrated under a reduced pressure to obtain Compound (ii) as a pale yellow oily product. The purity thereof determined by NMR spectrum was about 87%. 
     Step (3): 
     40.8 g (0.2 mol) of 2-carboxy-1,4-naphthohydroquinone was dissolved in 150 ml of N,N-dimethylformamide (DMF) and the solution was stirred at 35° to 40° C. under a nitrogen gas atmosphere. 75 g (2.5 equivalents) of a 28% methanol solution of sodium methoxide was added dropwise thereto and after 30 minutes 100 ml of dimethylformamide solution containing 75 g (1.2 equivalents) of the oily product obtained in Step (2) was added thereto over a period of 40 minutes. After 2 hours, the reaction mixture was poured into 400 ml of ice water and a pH of the mixture was adjusted to about 5 with concentrated hydrochloric acid with stirring. After 1.5 hours, the crystals thus precipitated were collected by filtration, washed with a mixture of water and acetonitrile (2:1 in volume ratio) and then crystallized with a solvent mixture of ethanol and n-hexane to obtain 51.6 g of Compound (iii) as light brown crystals. 
     Step (4): 
     43.7 g (0.1 mol) of the crystals of Compound (iii) obtained in Step (3) and 20 g (0.15 mol) of p-nitrophenol were dissolved in 350 ml of toluene and to the solution was added 24 g (0.2 mol) of thionyl chloride at 60° to 64° C. with stirring over a period of 20 minutes. After being reacted at about 70° C. for 3 hours, the mixture was gradually cooled to room temperature and allowed to stand overnight. The crystals thus precipitated were collected by filtration, washed with acetonitrile and dried under a reduced pressure to obtain 39.7 g of Compound (iv) as pale yellow crystals. 
     Step (5): 
     A mixture of 35 g (0.063 mol) of the crystals of Compound (iv) obtained in Step (4), 11.6 g (0.063 mol) of dodecylamine and 200 ml of acetonitrile was refluxed for 35 minutes and gradually cooled to room temperature. The crystals thus precipitated were collected by filtration and washed with cold acetonitrile. The crude crystals thus obtained were added to 170 ml of acetonitrile, the solution was treated with 10 g of active carbon and filtered. The filtrate was crystallized at room temperature while gradually stirring. The crystals thus precipitated were collected by filtration and dried to obtain 28.3 g of Compound (1) as light gray crystals. The structure of the compound was confirmed by IR spectrum, NMR spectrum and mass spectrum. 
     SYNTHESIS EXAMPLE 2 
     Synthesis of Compound (6) 
     Compound (6) was synthesized according to the following synthesis route: ##STR23## 
     Step (1): 
     To a mixture of 88.2 g (0.6 mol) of 5,6-dimethylbenzotriazole, 101 g (0.72 mol) of bromoacetic acid and 500 ml of acetonitrile was added 167 ml (1.2 mol) of triethylamine at room temperature with stirring over a period of 25 minutes and the mixture was reacted for 3 hours. The reaction mixture was poured into 1 liter of cold water and the pH of the mixture was adjusted to about 6 with concentrated hydrochloric acid and extracted using 2 liters of ethyl acetate. The extract was dried with anhydrous sodium sulfate and concentrated under a reduced pressure. The residue was crystallized using a solvent mixture of ether and acetonitrile to obtain 98.6 g of Compound (v) as crystals. 
     Step (2): 
     82.8 g (0.4 mol) of the crystals of Compound (v) obtained in Step (1) was dissolved in 200 ml of thionyl chloride and the solution was refluxed for 1 hour. After cooling to room temperature, 32 ml (0.4 mol) of sulfuryl chloride was added thereto over a period of 35 minutes. After 1 hour the mixture was heated to 50° to 55° C. and further reacted for 1 hour. The excessive reagents were distilled off under a reduced pressure and to the residue was added 100 ml of isopropyl alcohol over a period of 10 minutes. The mixture was reacted at 60° C. for 3 hours and then the reaction mixture was concentrated under a reduced pressure and to the residue was added 500 ml of ethyl acetate. The ethyl acetate solution was washed twice with each 200 ml of water and dried. 20 g of active carbon was added to the solution, the mixture was stirred for 30 minutes and filtered to remove active carbon. The filtrate was concentrated under a reduced pressure and then the residue was dried for 5 hours using a vacuum pump to obtain 86.3 g of Compound (vi) as an amorphous product. The purity thereof determined by NMR spectrum was about 92%. 
     Step (3): 
     71.4 g (0.2 mol) of 5-nitro-2-(3,4-dichlorophenylureido)-p-hydroquinone was added to 150 ml of dimethylformamide and to the mixture was added 24.6 g (0.22 mol) of potassium tert-butoxide with stirring at 40° to 45° C. under a nitrogen atmosphere. After 30 minutes, 70 ml of a dimethylformamide solution containing 61 g (0.2 mol) of Compound (vi) obtained in Step (2) was added over a period of 20 minutes and the mixture was reacted for 2 hours. The reaction mixture was poured into 400 ml of cold water and a pH of the mixture was adjusted to about 5 with concentrated hydrochloric acid. After 2 hours, the crystals thus precipitated were collected by filtration and crystallized with acetonitrile to obtain 69.2 g of Compound (vii) as crystals. 
     Step (4): 
     To a mixture of 56 g of iron powder, 3.5 g of ammonium chloride, 40 ml of water and 300 ml of isopropyl alcohol was added 3.5 ml of acetic acid, the mixture was refluxed for 20 minutes and 60 g (0.1 mol) of the crystals of Compound (vii) obtained in Step (3) was added thereto for 30 minutes. After 15 minutes, the mixture was filtered through celite and the solid was washed with 100 ml of hot isopropyl alcohol. The filtrate was concentrated to 2/3 of the original volume under a reduced pressure and the residue was allowed to stand at room temperature. After 3 hours, the crystals thus precipitated were collected by filtration, washed with isopropyl alcohol and dried under a reduced pressure to obtain 43.7 g of Compound (viii) as crystals. 
     Step (5): 
     A mixture of 40 g (0.07 mol) of the crystals of Compound (viii) obtained in Step (4), 300 ml of acetonitrile and 50 ml of dimethylformamide was refluxed with stirring, to which was added dropwise 50 ml of an acetonitrile solution containing 27.6 g (0.07 mol) of 2-(2,4-di-tert-pentylphenoxy)octanoyl chloride over a period of 30 minutes. After 3 hours, the mixture was concentrated under a reduced pressure and to the residue were added 500 ml of ethyl acetate and 200 ml of water to extract. The pH of the upper layer was adjusted to about 5 with a 5% aqueous solution of sodium hydrogencarbonate, the organic layer was separated, dried with anhydrous sodium sulfate and concentrated using an evaporator. The residue was crystallized with a solvent mixture of ethyl acetate and n-hexane to obtain 31.8 g of Compound (6). The structure of the compound was confirmed by IR spectrum, NMR spectrum and mass spectrum. 
     SYNTHESIS EXAMPLE 3 
     Synthesis of Compound (31) 
     Compound (31) was synthesized according to the following reaction scheme: ##STR24## 
     Step (1): Preparation of Compound (c) 
     47.7 g (0.37 mol) of 3-ethylhydantoin (Compound (a)) was dissolved in 220 ml of acetic acid and the solution was heated at 90° to 95° C. To the solution was added a solution of 71.5 g (1.2 equivalents) of bromide in 20 ml of acetic acid over a period of 30 minutes. After 1 hour, the reaction mixture was concentrated under a reduced pressure using an aspirator, the residue was dissolved in 350 ml of tetrahydrofuran (THF). The tetrahydrofuran solution was added dropwise to a solution of 116 g (2.1 equivalents) of benzotriazole (Compound (b)) in 500 ml of tetrahydrofuran at 45° to 50° C. After 2.5 hours, the crystals thus precipitated were removed off by filtration and the filtrate was concentrated. The residue was dissolved in 1 liter of ethyl acetate, the solution was washed twice with water (pH of 4), dried with anhydrous sodium sulfate and concentrated. The residue was recrystallized from ethyl acetate and the crystals thus precipitated were collected by filtration. The filtrate was concentrated and crystallized twice. Thereby, 38 g of Compound (c) (melting point: more than 165° C. (dec.)) was obtained. The structure of the compound was confirmed by mass spectrum and NMR spectrum. 
     Step (2): Synthesis of Compound (31) 
     22 g (0.04 mol) of chloride of mother coupler (Compound (d)) and 10.8 g (0.04 mol) of Compound (c) obtained in Step (1) were dissolved in 100 ml of N,N-dimethylacetoamide and stirred at 50° to 55° C. To the solution was added 12.1 ml (0.1 mol) of triethylamine and reacted for 3 hours. The reaction mixture was poured into 500 ml of ethyl acetate, washed with a 0.1M HCl aqueous solution, dried with anhydrous sodium sulfate. The ethyl acetate solution was concentrated, and the residue was separated by silica gel column chromatography (elution by a solvent mixture of chloroform/ethyl acetate=20/1). By crystallization from diisopropyl ether, the desired Compound (31) was obtained as crystals (yield: 15.4 g, melting point: 132°-135° C.). The structure of the Compound (31) was confirmed by mass spectrum, NMR spectrum and elementary analysis. 
     Other specific compounds as described above can also be synthesized with reference to the methods for syntheses of Compounds (1) and (6) as described above. 
     In order to incorporate the compounds according to the present invention and couplers to be used together into a silver halide emulsion layer, known methods including those described, e.g., in U.S. Pat. No. 2,322,027 can be used. For example, they can be dissolved in a solvent and then dispersed in a hydrophilic colloid. Examples of solvents usable for this process include organic solvents having a high boiling point, such as alkyl esters of phthalic acid (e.g., dibutyl phthalate, dioctyl phthalate, etc.), phosphoric acid esters (e.g., diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, dioctyl butyl phosphate, etc.), citric acid esters (e.g., tributyl acetyl citrate, etc.), benzoic acid esters (e.g., octyl benzoate, etc.), alkylamides (e.g., diethyllaurylamides, etc.), esters of fatty acids (e.g., dibutoxyethyl succinate, diethyl azelate, etc.), trimesic acid esters (e.g., tributyl trimesate, etc.), or the like; and organic solvents having a boiling point of from about 30° to about 150° C., such as lower alkyl acetates (e.g., ethyl acetate, butyl acetate, etc.), ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, β-ethoxyethyl acetate, methyl cellosolve acetate, or the like. Mixtures of the organic solvents having a high boiling point and the organic solvents having a low boiling point described above can also be used. 
     It is also possible to utilize the dispersing method using polymers, as described in Japanese Patent Publication No. 39853/76 and Japanese Patent Application (OPI) No. 59943/76. 
     Of the couplers, those having an acid group, such as a carboxylic acid group or a sulfonic acid group, can be introduced into hydrophilic colloids as an aqueous alkaline solution. 
     As the binder or the protective colloid for the photographic emulsion layers or intermediate layers of the photographic light-sensitive material of the present invention, gelatin is advantageously used, but other hydrophilic colloids can be used alone or together with gelatin. 
     As gelatin in the present invention, not only lime-processed gelatin, but also acid-processed gelatin may be employed. The methods for preparation of gelatin are described in greater detail in Ather Veis, The Macromolecular Chemistry of Gelatin, Academic Press (1964). 
     As the above-described hydrophilic colloids other than gelatin, it is possible to use proteins such as gelatin derivatives, graft polymers of gelatin and other polymers, albumin, casein, etc.; saccharides such as cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate, etc., sodium alginate, starch derivatives, etc.; and various synthetic hydrophilic high molecular weight substances such as homopolymers or copolymers, for example, polyvinyl alcohol, polyvinyl alcohol semiacetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinyl imidazole, polyvinyl pyrazole, etc. 
     In the photographic emulsion layer of the photographic light-sensitive material used in the present invention, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide and silver chloride may be used as the silver halide. A preferred silver halide is silver iodobromide containing 15 mol% or less of silver iodide. A silver iodobromide emulsion containing from 2 mol% to 12 mol% of silver iodide is particularly preferred. 
     Although the mean grain size of silver halide particles in the photographic emulsion (the mean grain size being determined with a grain diameter in those particles which are spherical or nearly spherical, and an edge length in those particles which are cubic as a grain size, and is expressed as a mean value calculated from projected areas) is not particularly limited, it is preferably 3 μm or less. 
     The distribution of grain size may be broad or narrow. 
     Silver halide particles in the photographic emulsion may have a regular crystal structure, e.g., a cubic or octahedral structure, an irregular crystal structure, e.g., a spherical or tabular structure, or a composite structure thereof. In addition, silver halide particles composed of those having different crystal structures may be used. 
     Further, the photographic emulsion wherein at least 50% of the total projected area of silver halide particles is super tabular silver halide particles having a diameter at least five times their thickness may be employed. 
     The inner portion and the surface layer of silver halide particles may be different in phase. Silver halide particles may be those in which a latent image is formed mainly on the surface thereof, or those in which a latent image is formed mainly in the interior thereof. 
     The photographic emulsion used in the present invention can be prepared in any suitable manner, e.g., by the methods as described in P. Glafkides, Chimie et Physique Photographique, Paul Montel (1967), G. F. Duffin, Photographic Emulsion Chemistry, The Focal Press (1966), and V. L. Zelikman et al., Making and Coating Photographic Emulsion, The Focal Press (1964). That is, any of an acid process, a neutral process, an ammonia process, etc., can be employed. 
     Soluble silver salts and soluble halogen salts can be reacted by techniques such as a single jet process, a double jet process, and a combination thereof. In addition, there can be employed a method (so-called reversal mixing process) in which silver halide particles are formed in the presence of an excess of silver ions. 
     As one system of the double jet process, a so-called controlled double jet process in which the pAg in a liquid phase where silver halide is formed is maintained at a predetermined level can be employed. This process can produce a silver halide emulsion in which the crystal form is regular and the grain size is nearly uniform. 
     Two or more kinds of silver halide emulsions which are prepared separately may be used as a mixture. 
     The formation or physical ripening of silver halide particles may be carried out in the presence of cadmium salts, zinc salts, lead salts, thallium salts, iridium salts or its complex salts, rhodium salts or its complex salts, iron salts or its complex salts, and the like. 
     For removal of soluble salts from the emulsion after precipitate formation or physical ripening, a well known noodle washing process in which gelatin is gelated may be used. In addition, a flocculation process utilizing inorganic salts having a polyvalent anion (e.g., sodium sulfate), anionic surface active agents, anionic polymers (e.g., polystyrenesulfonic acid), or gelatin derivatives (e.g., aliphatic acylated gelatin, aromatic acylated gelatin and aromatic carbamoylated gelatin) may be used. 
     Silver halide emulsions are usually chemically sensitized. For this chemical sensitization, for example, the methods as described in H. Frieser ed., Die Grundlagen der Photographischen Prozesse mit Silberhalogeniden, Akademische Verlagsgesellschaft, pages 675-734 (1968) can be used. Namely, a sulfur sensitization process using active gelatin or compounds (e.g., thiosulfates, thioureas, mercapto compounds and rhodanines) containing sulfur capable of reacting with silver; a reduction sensitization process using reducing substances (e.g., stannous salts, amines, hydrazine derivatives, formamidinesulfinic acid, and silane compounds); a noble metal sensitization process using noble metal compounds (e.g., complex salts of Group VIII metals in the Periodic Table, such as Pt, Ir and Pd, etc., as well as gold complex salts); and so forth can be applied alone or in combination with each other. 
     The photographic emulsion used in the present invention may include various compounds for the purpose of preventing fog formation or of stabilizing photographic performance in the photographic light-sensitive material during the production, storage or photographic processing thereof. For example, these compounds known as antifoggants or stabilizers can be incorporated, including azoles such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (particularly 1-phenyl-5-mercaptotetrazole), etc.; mercaptopyrimidines; mercaptotriazines; thioketo compounds such as oxazolinethione, etc.; azaindenes such as triazaindenes, tetraazaindenes (particularly 4-hydroxy-substituted (1,3,3a,7)tetraazaindenes), pentaazaindenes, etc.; benzenethiosulfonic acids; benzenesulfinic acids; benzenesulfonic amides; etc. 
     In the photographic emulsion layers or other hydrophilic colloid layers of the photographic light-sensitive material of the present invention can be incorporated various surface active agents as coating acids or for other various purposes, e.g., prevention of charging, improvement of slipping properties, acceleration of emulsification and dispersion, prevention of adhesion, and improvement of photographic characteristics (for example, development acceleration, high contrast, and sensitization), etc. 
     Surface active agents which can be used are nonionic surface active agents, e.g., saponin (steroid-based), alkylene oxide derivatives (e.g., polyethylene glycol, a polyethylene glycol/polypropylene glycol condensate, polyethylene glycol alkyl ethers or polyethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines or polyalkylene glycol alkylamides, and silicone/polyethylene oxide adducts, etc.), glycidol derivatives (e.g., alkenylsuccinic acid polyglyceride and alkylphenol polyglyceride, etc.), fatty acid esters of polyhydric alcohols, and alkyl esters of sugar, etc.; anionic surface active agents containing an acidic group, such as a carboxy group, a sulfo group, a phospho group, a sulfuric acid ester group, and a phosphoric acid ester group, for example, alkylcarboxylic acid salts, alkylsulfonic acid salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfuric acid esters, alkylphosphoric acid esters, N-acyl-N-alkyltaurines, sulfosuccinic acid esters, sulfoalkylpolyoxyethylene alkylphenyl ethers, and polyoxyethylene alkylphosphoric acid esters; amphoteric surface active agents, such as amino acids, aminoalkylsulfonic acids, aminoalkylsulfuric acid or aminoalkylphosphoric acid esters, alkylbetaines, and amine oxides; and cationic surface active agents, e.g., alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts (e.g., pyridinium and imidazolium), and aliphatic or heterocyclic phosphonium or sulfonium salts. 
     The photographic emulsion layer of the photographic light-sensitive material of the present invention may contain compounds such as polyalkylene oxide or its ether, ester, amine or like derivatives, thioether compounds, thiomorpholines, quaternary ammonium salt compounds, urethane derivatives, urea derivatives, imidazole derivatives, and 3-pyrazolidones for the purpose of increasing sensitivity or contrast, or of accelerating development. 
     In the photographic emulsion layer or other hydrophilic colloid layers of the photographic light-sensitive material of the present invention can be incorporated water-insoluble or sparingly soluble synthetic polymer dispersions for the purpose of improving dimensional stability, etc. Synthetic polymers which can be used include homo- or copolymers of alkyl acrylate or methacrylate, alkoxyalkyl acrylate or methacrylate, glycidyl acrylate or methacrylate, acrylamide or methacrylamide, vinyl esters (e.g., vinyl acetate), acrylonitrile, olefins, styrene, etc., and copolymers of the foregoing monomers and acrylic acid, methacrylic acid, α,β-unsaturated dicarboxylic acid, hydroxyalkyl acrylate or methacrylate, sulfoalkyl acrylate or methacrylate, and styrenesulfonic acid, etc. 
     In photographic processing of layers composed of photographic emulsions in the photographic light-sensitive material of the present invention, any of known procedures and known processing solutions, e.g., those described in Research Disclosure, No. 176, pages 28-30 can be used. The processing temperature is usually chosen from between 18° C. and 50° C., although it may be lower than 18° C. or higher than 50° C. 
     Any fixing solutions which have compositions generally used can be used in the present invention. As fixing agents, thiosulfuric acid salts and thiocyanic acid salts, and in addition, organic sulfur compounds which are known to be effective as fixing agents can be used. These fixing solutions may contain water-soluble aluminum salts as hardeners. 
     Color developing solutions are usually alkaline aqueous solutions containing color developing agents. As these color developing agents, known primary aromatic amine developing agents, e.g., phenylenediamines such as 4-amino-N,N-diethylaniline, 3-methyl-4-amino-N,N-diethylaniline, 4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfonamidoethylaniline, 4-amino-3-methyl-N-ethyl-N-β-methoxyethylaniline, etc., can be used. 
     In addition, the compounds as described in L. F. A. Mason, Photographic Processing Chemistry, Focal Press, pages 226-229 (1966), U.S. Pat. Nos. 2,193,015 and 2,592,364, Japanese Patent Application (OPI) No. 64933/72, etc., may be used. 
     The color developing solutions can further contain pH buffering agents such as sulfite, carbonates, borates and phosphates of alkali metals, etc., developing inhibitors or antifogging agents such as bromides, iodides or organic antifogging agents, etc. In addition, if desired, the color developing solutions can also contain water softeners; preservatives such as hydroxylamine, etc.; organic solvents such as benzyl alcohol, diethylene glycol, etc.; developing accelerators such as polyethylene glycol, quaternary ammonium salts, amines, etc.; dye forming couplers; competing couplers; fogging agents such as sodium borohydride, etc.; auxiliary developing agents such as 1-phenyl-3-pyrazolidone, etc.; viscosity imparting agents; polycarboxylic acid type chelating agents; antioxidizing agents; and the like. 
     After color development, the photographic emulsion layer is usually bleached. This bleach processing may be performed simultaneously with a fix processing, or they may be performed independently. 
     Bleaching agents which can be used include compounds of polyvalent metals, e.g., iron (III), cobalt (III), chromium (VI), and copper (II), peracids, quinones and nitroso compounds. For example, ferricyanides; dichromates; organic complex salts of iron (III) or cobalt (III), e.g., complex salts of aminopolycarboxylic acids (e.g., ethylenediaminetetraacetic acid, nitrilotriacetic acid, 1,3-diamino-2-propanoltetraacetic acid, etc.) or organic acids (e.g., citric acid, tartaric acid, malic acid, etc.); persulfates; permanganates; nitrosophenol, etc., can be used. Of these compounds, potassium ferricyanide, iron (III) sodium ethylenediaminetetraacetate, and iron (III) ammonium ethylenediaminetetraacetate are particularly useful. Ethylenediaminetetraacetic acid iron (III) complex salts are useful in both an independent bleaching solution and a monobath bleach-fixing solution. 
     The photographic emulsion used in the present invention can also be spectrally sensitized with methine dyes or other dyes. Suitable dyes which can be employed include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Of these dyes, cyanine dyes, merocyanine dyes and complex merocyanine dyes are particularly useful. 
     Any conventionally utilized nuclei for cyanine dyes are applicable to these dyes as basic heterocyclic nuclei. That is, 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, a pyridine nucleus, etc., and further, nuclei formed by condensing alicyclic hydrocarbon rings with these nuclei and nuclei formed by condensing aromatic hydrocarbon rings with these nuclei, that is, 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, a quinoline nucleus, etc., are appropriate. The carbon atoms of these nuclei can also be substituted. 
     The merocyanine dyes and the complex merocyanine dyes that can be employed contain 5- or 6-membered heterocyclic nuclei such as a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thioxazolidin-2,4-dione nucleus, a thiazolidine-2,4-dione nucleus, a rhodanine nucleus, a thiobarbituric acid nucleus, and the like as a nucleus having a ketomethylene structure. 
     These sensitizing dyes can be employed individually, and can also be employed in combination. A combination of sensitizing dyes is often used particularly for the purpose of supersensitization. 
     The sensitizing dyes may be present in the emulsion together with dyes which themselves do not have spectrally sensitizing effects but exhibit a supersensitizing effect or materials which do not substantially absorb visible light but exhibit a supersensitizing effect. For example, aminostilbene compounds substituted with a nitrogen-containing heterocyclic group (e.g., those described in U.S. Pat. Nos. 2,933,390 and 3,635,721), aromatic organic acid-formaldehyde condensates (e.g., those described in U.S. Pat. No. 3,743,510), cadmium salts, azaindene compounds, and the like, can be present. 
     The present invention is also applicable to a multilayer multicolor photographic material containing layers sensitive to at least two different spectral wavelength ranges on a support. A multilayer natural color photographic material generally possesses at least one red-sensitive silver halide emulsion layer, at least one green-sensitive silver halide emulsion layer and at least one blue-sensitive silver halide emulsion layer, respectively, on a support. The order of these layers can be varied, if desired. Ordinarily, a cyan forming coupler is present in a red-sensitive emulsion layer, a magenta forming coupler is present in a green-sensitive emulsion layer and a yellow forming coupler is present in a blue-sensitive emulsion layer, respectively. However, if desired, a different combination can be employed. 
     The same or different photographic emulsion layers or light-insensitive layers of the photographic light-sensitive material of the present invention can be incorporated, in addition to the compounds according to the present invention described above, with other dye forming couplers, e.g., compounds capable of forming color upon oxidative coupling with aromatic primary amine developing agents (e.g., phenylenediamine derivatives, aminophenol derivatives, etc.) during the course of color development processing. Examples of such couplers include magenta couplers, such as 5-pyrazolone couplers, pyrazolobenzimidazole couplers, pyrazoloimidazole couplers, pyrazolopyrazole couplers, pyrazolotriazole couplers, pyrazolotetrazole couplers, cyanoacetyl coumarone couplers and open chain acylacetonitrile couplers, etc.; yellow couplers, such as acylacetamide couplers (e.g., benzoylacetanilides, pivaloylacetanilides, etc.), etc.; and cyan couplers, such as naphthol couplers and phenol couplers, etc. It is preferable to use non-diffusible couplers containing a hydrophobic group (so-called ballast group) within the molecule or polymeric couplers. They may be either 4-equivalent or 2-equivalent with respect to silver ions. It is also possible to use colored couplers capable of exerting color correction effects, or couplers capable of releasing development inhibitors during the course of development (so-called DIR couplers). 
     Further, the emulsion layer may contain noncolor-forming DIR coupling compounds which release a development inhibitor, the product of which formed by a coupling reaction is colorless, other than DIR couplers. 
     Moreover, the photographic light-sensitive material may contain compounds which release a development inhibitor during the course of development, other than DIR couplers. 
     Two or more kinds of the compounds according to the present invention and the above-described couplers and the like can be incorporated together in the same layer for the purpose of satisfying the properties required of the photographic light-sensitive material, or the same compound can be separately added to two or more layers. 
     The photographic light-sensitive material of the present invention may contain inorganic or organic hardeners in the photographic emulsion layer and other hydrophilic colloid layers thereof. For example, chromium salts (e.g., chromium alum, chromium acetate, etc.), aldehydes (e.g., formaldehyde, glyoxal, glutaraldehyde, etc.), N-methylol compounds (e.g., dimethylolurea, methyloldimethylhydantoin, etc.), dioxane derivatives (e.g., 2,3-dihydroxydioxane, etc.), active vinyl compounds (e.g., 1,3,5-triacryloylhexahydro-s-triazine, 1,3-vinylsulfonyl-2-propanol, etc.), active halogen compounds (e.g., 2,4-dichloro-6-hydroxy-s-triazine, etc.), and mucohalogenic acids (e.g., mucochloric acid, mucophenoxychloric acid, etc.) can be used alone or in combination with each other. 
     In the photographic light-sensitive material of the invention, when dyes, ultraviolet ray absorbing agents, and the like are incorporated in the hydrophilic colloid layers, they may be mordanted with cationic polymers, etc. 
     The photographic light-sensitive material of the present invention may contain therein hydroquinone derivatives, aminophenol derivatives, gallic acid derivatives, ascorbic acid derivatives, etc., as color fog preventing agents. 
     The hydrophilic colloid layers of the photographic light-sensitive material of the present invention can contain ultraviolet ray absorbing agents. For example, benzotriazole compounds substituted with aryl groups (e.g., those described in U.S. Pat. No. 3,533,794), 4-thiazolidone compounds (e.g., those described in U.S. Pat. Nos. 3,314,794 and 3,352,681), benzophenone compounds (e.g., those described in Japanese Patent Application (OPI) No. 2784/71), cinnamic acid ester compounds (e.g., those described in U.S. Pat. Nos. 3,705,805 and 3,707,375), butadiene compounds (e.g., those described in U.S. Pat. No. 4,045,229) or benzoxazole compounds (e.g., those described in U.S. Pat. No. 3,700,455) can be employed. Ultraviolet ray absorbing couplers (e.g., α-naphthol type cyan dye forming couplers) and ultraviolet ray absorbing polymers can also be employed. These ultraviolet ray absorbing agents can also be mordanted in a specific layer(s), if desired. 
     The photographic light-sensitive material of the present invention may contain water-soluble dyes in the hydrophilic colloid layers thereof as filter dye or for various purposes, e.g., irradiation prevention. Examples of such dyes include oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes, cyanine dyes, and azo dyes. In particular, oxonol dyes, hemioxonol dyes, and merocyanine dyes are useful. 
     In carrying out the present invention, known color fading preventing agents as described below can be used together. Color image stabilizers can be used alone or in combination with each other. Typical known color fading preventing agents include hydroquinone derivatives, gallic acid derivatives, p-alkoxyphenols, p-oxyphenol derivatives, and bisphenols, etc. 
     The present invention will be explained in greater detail with reference to the following examples, but the present invention should be construed as being limited thereto. 
     Unless otherwise indicated, all percents, ratios, etc., are by weight. 
     EXAMPLE 1 
     On a polyethylene terephthalate film support were coated layers having the compositions set forth below to prepare a multilayer color photographic light-sensitive material. 
     First Layer: Antihalation Layer 
     A gelatin layer containing black colloidal silver. 
     Second Layer: Intermediate Layer 
     A gelatin layer containing a dispersion of 2,5-di-tert-octylhydroquinone. 
     Third Layer: First Red-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 5 mol%), silver coated amount: 1.6 g/m 2 . 
     Sensitizing Dye I: 4.5×10 -4  mol per mol of silver 
     Sensitizing Dye II: 1.5×10 -4  mol per mol of silver 
     Coupler EX-1: 0.03 mol per mol of silver 
     Coupler EX-3: 0.003 mol per mol of silver. 
     Fourth Layer: Second Red-SEnsitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 10 mol%), silver coated amount: 1.4 g/m 2 . 
     Sensitizing Dye I: 3×10 -4  mol per mol of silver 
     Sensitizing Dye II: 1×10 -4  mol per mol of silver 
     Coupler EX-1: 0.002 mol per mol of silver 
     Coupler EX-2: 0.02 mol per mol of silver 
     Coupler EX-3: 0.0016 mol per mol of silver. 
     Fifth Layer: Intermediate Layer 
     Same as the Second Layer 
     Sixth Layer: First Green-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 6 mol%), silver coated amount: 1.8 g/m 2 . 
     Sensitizing Dye III: 5×10 -4  mol per mol of silver 
     Sensitizing Dye IV: 2×10 -4  mol per mol of silver 
     Coupler EX-4: 0.05 mol per mol of silver 
     Coupler EX-5: 0.008 mol per mol of silver 
     Coupler EX-9: 0.0015 mol per mol of silver. 
     Seventh Layer: Second Green-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 8 mol%), silver coated amount: 1.3 g/m 2 . 
     Sensitizing Dye III: 3×10 -4  mol per mol of silver 
     Sensitizing Dye IV: 1.2×10 -4  mol per mol of silver 
     Coupler EX-7: 0.017 mol per mol of silver 
     Coupler EX-6: 0.003 mol per mol of silver. 
     Eighth Layer: Yellow Filter Layer 
     A gelatin layer containing yellow colloidal silver and a dispersion of 2,5-di-tert-octylhydroquinone. 
     Ninth Layer: First Blue-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 6 mol%), silver coated amount: 0.7 g/m 2 . 
     Coupler EX-8: 0.25 mol per mol of silver 
     Coupler EX-9: 0.015 mol per mol of silver 
     Tenth Layer: Second Blue-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 6 mol%), silver coated amount: 0.6 g/m 2 . 
     Coupler EX-8: 0.06 mol per mol of silver 
     Eleventh Layer: First Protective Layer 
     A gelatin layer containing silver iodobromide (iodide content: 1 mol%, average particle size: 0.07 μm, silver coated amount: 0.5 g/m 2 ) and a dispersion of Ultraviolet Ray Absorbing Agent UV-1. 
     Twelfth Layer: Second Protective Layer 
     A gelatin layer containing polymethyl methacrylate particles (having a diameter of about 1.5 μm) 
     Gelatin Hardener H-1 and a surface active agent were incorporated into each of the layers in addition to the above-described components. 
     The sample thus prepared was designated Sample 101. 
     Preparation of Samples 102 to 110 
     Samples 102 to 110 were prepared in the same manner as described for Sample 101 except changing Coupler EX-9 used in the first green-sensitive emulsion layer to the compounds as shown in Table 1 below, respectively. 
     The structure of the compounds used for preparing these samples are as follows: ##STR25## 
     Samples 101 to 110 were subjected to wedge exposure to white light and then development processing at 38° C. according to the following processing steps. 
     
         ______________________________________                                    
Processing Steps Time                                                     
______________________________________                                    
1. Color Development                                                      
                 3 min and 15 sec                                         
2. Bleaching     6 min and 30 sec                                         
3. Washing with Water                                                     
                 3 min and 15 sec                                         
4. Fixing        6 min and 30 sec                                         
5. Washing with Water                                                     
                 3 min and 15 sec                                         
6. Stabilizing   3 min and 15 sec                                         
______________________________________                                    
 
    
     The composition of each processing solution used in the above-described processing is as follows. 
     Color Developing Solution 
     Sodium Nitrilotriacetate: 1.0 g 
     Sodium Sulfite: 4.0 g 
     Sodium Carbonate: 30.0 g 
     Potassium Bromide: 1.4 g 
     Hydroxylamine Sulfate: 2.4 g 
     4-(N-Ethyl-N-β-hydroxyethylamino)-2-methylaniline Sulfate: 4.5 g 
     Water to make: 1 liter 
     Bleaching Solution 
     Ammonium Bromide: 160.0 g 
     Aqueous Ammonia (28%): 25.0 ml 
     Sodium Ethylenediaminetetraacetato Iron (III): 130.0 g 
     Glacial Acetic Acid: 14.0 ml 
     Water to make: 1 liter 
     Fixing Solution 
     Sodium Tetrapolyphosphate: 2.0 g 
     Sodium Sulfite: 4.0 g 
     Ammonium Thiosulfate Aqueous Solution (70%): 175.0 ml 
     Sodium Bisulfite: 4.6 g 
     Water to make: 1 liter 
     Stabilizing Solution 
     Formalin: 8.0 ml 
     Water to make: 1 liter 
     The samples thus processed exhibited almost the same sensitivity and gradation. The sharpness of the green-sensitive layers of these samples were evaluated using conventional MTF values at spatial frequencies of 4 cycles/mm and 40 cycles/mm. The results obtained are shown in Table 1 below. 
     
                       TABLE 1                                                     
______________________________________                                    
         Compound                                                         
         Added to          MTF Value                                      
           First Green-               40                                  
           Sensitive  Amount   4 Cycles/                                  
                                      Cycles/                             
Sample     Layer*     Added**  mm     mm                                  
______________________________________                                    
101 (Comparison)                                                          
           EX-9       1.0      1.03   0.42                                
102 (Comparison)                                                          
           EX-10      1.0      1.01   0.38                                
103 (Comparison)                                                          
           EX-11      2.0      1.10   0.50                                
104 (Invention)                                                           
           (3)        2.0      1.16   0.57                                
105 (Invention)                                                           
           (4)        2.0      1.18   0.58                                
106 (Invention)                                                           
           (5)        2.0      1.17   0.58                                
107 (Invention)                                                           
           (10)       1.5      1.15   0.56                                
108 (Invention)                                                           
           (14)       1.5      1.14   0.54                                
109 (Invention)                                                           
           (6)        1.5      1.19   0.58                                
110 (Invention)                                                           
           (21)       2.0      1.17   0.56                                
______________________________________                                    
 *Compound added in place of Coupler EX9 to the first greensensitive      
 emulsion layer.                                                          
 **Amount added is indicated using a molar ratio taking the mole of Couple
 EX9 added as 1.                                                          
 
    
     From the results shown in Table 1 above, it is understood that the MTF values in case of using the compounds according to the present invention are extremely high in comparison with in case of using the conventional DIR couplers. 
     EXAMPLE 2 
     On a polyethylene terephthalate film support were coated layers having the compositions set forth below to prepare a multilayer color photographic light-sensitive material. 
     First Layer: Antihalation Layer 
     A gelatin layer containing black colloidal silver. 
     Second Layer: Intermediate Layer 
     A gelatin layer containing a dispersion of 2,5-ditert-octylhydroquinone. 
     Third Layer: Red-Sensitive Emulsion Layer 
     A silver iodobromide emulsion (iodide content: 7 mol%), silver coated amount: 2.0 g/m 2 . 
     Sensitizing Dye I: 4.5×10 -4  mol per mol of silver 
     Sensitizing Dye II: 1.5×10 -4  mol per mol of silver 
     Coupler EX-1: 0.04 mol per mol of silver 
     Coupler EX-3: 0.003 mol per mol of silver 
     Coupler Ex-9: 0.004 mol per mol of silver 
     Tricresyl Phosphate: 0.5 g/m 2   
     Dibutyl Phthalate: 0.2 g/m 2   
     Fourth Layer: First Protective Layer 
     A gelatin layer containing silver iodobromide (iodide content: 1 mol%, average particle size: 0.07 μm, silver coated amount: 0.5 g/m 2 ) and a dispersion of Ultraviolet Ray Absorbing Agent UV-1. 
     Fifth Layer: Second Protective Layer 
     A gelatin layer containing polymethyl methacrylate particles (having a diameter of about 1.5 μm). 
     Gelatin Hardener H-1 and a surface active agent were incorporated into each of the layers in addition to the above-described components. 
     The sample thus prepared was designated Sample 111. 
     Preparation of Samples 112 to 122 
     Samples 112 to 122 were prepared in the same manner as described for Sample 111 except changing Coupler EX-9 used in the green-sensitive emulsion layer to the compounds as shown in Table 2 below, respectively. 
     The structures of the compounds used for preparing these samples are the same as those described in Example 1, except Coupler EX-12 which has the following structure. ##STR26## 
     Samples 111 to 122 were subjected to wedge exposure to white light and then development processing in the same manner as described in Example 1. The samples thus processed exhibited almost the same sensitivity and gradation. The MTF values at spatial frequencies of 4 cycles/mm and 40 cycles/mm were measured with these samples. The results obtained are shown in Table 2 below. 
     
                       TABLE 2                                                     
______________________________________                                    
         DIR Coupler                                                      
                    MTF Value                                             
           Kind    Amount            40                                   
Sample     Used    Added    4 Cycles/mm                                   
                                     Cycles/mm                            
______________________________________                                    
111 (Comparison)                                                          
           EX-9    1.0      1.11     0.58                                 
112 (Comparison)                                                          
           EX-11   1.5      1.15     0.62                                 
113 (Comparison)                                                          
           EX-12   1.5      1.14     0.62                                 
114 (Invention)                                                           
           (1)     1.0      1.18     0.67                                 
115 (Invention)                                                           
           (2)     1.5      1.25     0.75                                 
116 (Invention)                                                           
           (6)     1.5      1.28     0.78                                 
117 (Invention)                                                           
           (7)     1.5      1.27     0.73                                 
118 (Invention)                                                           
           (9)     1.0      1.19     0.66                                 
119 (Invention)                                                           
           (10)    1.0      1.18     0.68                                 
120 (Invention)                                                           
           (30)    1.5      1.27     0.76                                 
121 (Invention)                                                           
           (31)    1.5      1.28     0.78                                 
122 (Invention)                                                           
           (32)    1.5      1.27     0.77                                 
______________________________________                                    
 
    
     From the results shown in Table 2 above, it is understood that the MTF values are extremely high in the case of using the compounds according to the present invention in comparison with the case of using the conventional DIR couplers. 
     EXAMPLE 3 
     In order to examine preservability of the films used in Example 2, Samples 113 to 116 were stored at 25° C. and 60% RH for 3 days or at 45° C. and 80% RH for 3 days respectively and then subjected to wedge exposure to white light and development processing at 20° C. according to the following processing steps. 
     
         ______________________________________                                    
Processing Steps   Time                                                   
______________________________________                                    
1. Development     10 min                                                 
2. Stopping         1 min                                                 
3. Fixing           5 min                                                 
4. Washing with Water                                                     
                   10 min                                                 
______________________________________                                    
 
    
     The composition of each processing solution used in the above-described processing is as follows. 
     Developing Solution 
     Sodium Sulfite: 33 g 
     Metol: 3 g 
     Hydroquinone: 3 g 
     Sodium Carbonate (monohydrate): 23 g 
     Potassium Bromide: 1.7 g 
     Water to make: 1 liter 
     Stopping Solution 
     Glacial Acetic Acid: 15 ml 
     Water to make: 1 liter 
     Fixing Solution 
     Sodium Thiosulfate: 191 g 
     Sodium Sulfite: 20 g 
     Glacial Acetic Acid: 20 ml 
     Water to make: 1 liter 
     The samples thus processed were subjected to sensitometry. The results obtained are shown in Table 3 below. 
     
                       TABLE 3                                                     
______________________________________                                    
                           Relative                                       
                DIR Coupler                                               
                           Sensitivity*                                   
Sample          Used       (%)                                            
______________________________________                                    
Blank           None       98                                             
113 (Comparison)                                                          
                EX-12      75                                             
114 (Invention) (1)        98                                             
115 (Invention) (2)        98                                             
116 (Invention) (6)        98                                             
______________________________________                                    
 *Relative sensitivity of the sample stored at 45° C. and 80% RH fo
 3 days to the sample stored at 25° C. and 60% RH for 3 days.      
 
    
     From the results shown in Table 3 above, it is apparent that the compounds according to the present invention do not release a development inhibitor upon hydrolysis during the preservation and thus do not cause a decrease in sensitivity. 
     As demonstrated in the above examples it can be understood that the photographic light-sensitive materials in which the compounds according to the present invention are used exhibit high MTF values at both areas of low spatial frequency and areas of high spatial frequency in not only multi-emulsion layer systems (as shown in Example 1) but also single-emulsion layer systems (as shown in Example 2) and thus they can provide excellent sharpness in comparison with photographic light-sensitive materials in which conventional DIR couplers are employed. 
     Further, the compounds according to the present invention do not release a development inhibitor when subjected to hydrolysis during preservation apart from conventional DIR couplers. As a result, a decrease in sensitivity is not observed (as shown in Example 3) and stability of the photographic light-sensitive materials during preservation is not destroyed. 
     Therefore, the silver halide color photographic light-sensitive materials according to the present invention are excellent in photographic properties especially in sharpness and have extremely good stability during preservation thereof. 
     While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.