JPS6330618B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic coupler, and more particularly to a 2,5-diacylaminophenol cyan coupler suitable for use in silver halide color photographic light-sensitive materials. Prior art and its problems Usually, in silver halide color photographic light-sensitive materials, exposed silver halide grains are reduced with an aromatic primary amine color developing agent, and the color developing agent produced at this time is oxidized. Dye images can be obtained by coupling the body with couplers that form yellow, magenta and cyan dyes. Cyan couplers widely used to form the cyan dyes are phenolic and naphtholic cyan couplers. In particular, what is desired to be improved in the phenolic cyan coupler used as the final image is that the cyan dye formed first has good spectral absorption characteristics, that is, the green region of the absorption spectrum (especially
500nm to 550nm) and the maximum absorption wavelength is long wavelength (640nm to 660nm), and the cyan dye formed second has sufficient fastness against light, heat, and moisture. , and that there is little contamination in the uncolored area under these storage conditions;
Thirdly, it must have good coloring properties, that is, it must have sufficient coloring sensitivity and coloring density.
Another advantage is that bleaching baths or bleach-fixing baths containing EDTA ferric salt as a main component cause little loss of color even if they become fatigued after long-term use. Therefore, many proposals have been made to improve these points. A 2,5-diacylaminophenol cyan coupler is a cyan coupler that is attracting attention as having particularly excellent properties regarding the fourth point. For example, the phenol described in US Pat. It is an aminophenol cyan coupler. 2,5-diacylaminophenol cyan couplers, which are known as specific compounds, have excellent heat resistance and spectral absorption characteristics of the cyan dye formed, but the coloring properties of the coupler itself and the dye It has a serious drawback that its light resistance is extremely poor. Therefore, in order to improve these drawbacks, a so-called 2-equivalent coupler was proposed, in which a fluorine atom was introduced at the 4-position of the phenol ring, which undergoes a coupling reaction with the oxidized product of a color developing agent.
It is described in the specification of No. 3758308. Although these couplers exhibit excellent color development, they have the undesirable property of causing yellow staining when exposed to light. In addition, a 2,5-diacylaminophenol cyan coupler having a pentafluorobenzamide group at the 2-position of the phenol ring has been disclosed in the U.S. Patent No.
3758308 and 3880661; on the other hand, a 2,5-diacylaminophenol cyan coupler having an 0-sulfonamidobenzamide group at the 2-position of the phenol ring was disclosed in JP-A No. 56
- Described in Publication No. 80045. These two,
Although 5-diacylaminophenol cyan couplers are satisfactory in terms of spectral absorption characteristics, they are not necessarily sufficient in terms of dye fastness. In addition, 2,5-diacylaminophenol cyan couplers having a sulfonamide group at the 5-position of the phenol ring have been developed.
No. 109630, No. 55-163537, No. 56-22235, No. 56-22235, No.
It is described in Publications No. 56-99341, No. 56-116030, No. 56-55945, and No. 56-80054. 2, which further has a benzamide group substituted with at least one fluorine atom at the 2-position of the phenol ring;
A 5-diacylaminophenol cyan coupler is described in JP-A-56-161542.
However, the dyes produced from these couplers are
Although it is excellent in robustness, it is insufficient in terms of spectral absorption characteristics. The present inventors have conducted intensive research to solve the above-mentioned drawbacks of conventional 2,5-diacylaminophenol-based cyan couplers, and have discovered that a certain type of ,5
- It has been discovered that diacylaminophenol-based cyan couplers have excellent spectral absorption characteristics and significantly improved image storage stability, and have already been described in Japanese Patent Application Nos. 142839/1983 and 142840/1983. . Although these cyan couplers overcome the various drawbacks mentioned above, when dissolving and dispersing them using an organic solvent such as ethyl acetate, the solubility in the organic solvent is insufficient, and a large amount of solvent is required. Moreover, it has been found that there is an inconvenience that the cyan coupler will precipitate unless the gelatin emulsion after dispersion is kept at a high temperature. Therefore, it can be said that producing photographic materials on an industrial scale using cyan couplers having such disadvantages will significantly impair productivity. Therefore, as a measure to improve solubility, it may be considered to introduce a linear, long-chain alkyl group into the 5-position acylamino group. However, when the present inventors investigated the solubility of a 2,5-diacylaminophenol cyan coupler in which a linear, long-chain alkyl group was introduced into the acylamino group at the 5-position, the solubility was still insufficient. It turned out to be. OBJECTS OF THE INVENTION The first object of the present invention is to provide a photographic coupler which has excellent solubility in organic solvents and exhibits good dispersion stability when dispersed in a silver halide emulsion using this organic solvent. It is about providing. A second object of the present invention is to provide a color-forming dye that has good spectral absorption characteristics, sensitivity, color density, and fastness to light, heat, and moisture, and to have good color contamination during storage of the dye image. The object of the present invention is to provide a photographic coupler that can suppress the The present inventors have discovered that the above object can be achieved by a photographic coupler represented by the following general formula [], and have completed the present invention. General formula [] [In the formula, R ₁ represents an alkenyl group, an alkynyl group, or a branched alkyl group. R ₂ is a hydrogen atom,
Represents an alkyl group or an aryl group. R ₃ represents an aryl group. X is -O-, -S-, -SO ₂
-, (-alkylene)-O-, (-alkylene)-S-
and (--alkylene)--SO ₂ -- represents a divalent bonding group. Ar represents an aryl group. Z represents a hydrogen atom or a group capable of being eliminated by a coupling reaction with an oxidized product of an aromatic primary amine color developing agent. ] Specific Description of the Invention In the present invention, the branched alkyl group represented by R ₁ in the general formula [ ] is, for example, a 1-methylheptyl group, 3,3-dimethylbutyl group, 1-methyldecyl group, 4-ethyl- 5-methyloctyl group, etc. The alkenyl group represented by R ₁ is, for example, a vinyl group, an allyl group, an i-propenyl group, etc., and the alkynyl group is, for example, an ethynyl group, a 2-propynyl group, a 1,3-butadienyl group, etc. The alkyl group represented by R ₂ in the general formula [] is preferably an alkyl group having 1 to 20 carbon atoms,
More preferred are alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, butyl,
Examples include i-butyl group, n-pentyl group, n-octyl group, benzyl group, and phenethyl group. The aryl group represented by R ₂ is, for example, a phenyl group, t
-Butylphenyl group, etc. In the present invention,
R ₂ preferably has a hydrogen atom or 1 or more carbon atoms
There are 8 alkyl groups. The aryl group represented by R ₃ in the general formula [] is
For example, phenyl group, naphthyl group, etc., preferably phenyl group. When this phenyl group has a substituent, these substituents include, for example, a halogen atom (preferably chlorine or bromine),
Alkyl group {preferably a straight chain or branched alkyl group having 1 to 20 carbon atoms (e.g. methyl group, t
-butyl group, t-pentyl group, t-octyl group,
dodecyl group, pentadecyl group, benzyl group, phenethyl group)}, aryl group (e.g. phenyl group),
a heterocyclic group (preferably a nitrogen-containing heterocyclic group), an alkoxy group {preferably a linear or branched alkyloxy group having 1 to 20 carbon atoms (e.g., a methoxy group, an ethoxy group, a t-butyloxy group, an octyloxy group) , decyloxy group, dodecyloxy group)}, aryloxy group (e.g. phenoxy group),
Hydroxyl group, acyloxy group {preferably an alkylcarbonyloxy group (e.g. acetoxy group) or an arylcarbonyloxy group (e.g. benzoyloxy group)}, hydroxycarbonyl group, alkoxycarbonyl group (preferably a linear chain having 1 to 20 carbon atoms) or branched alkyloxycarbonyl group), aryloxycarbonyl group (preferably phenoxycarbonyl group), mercapto group, alkylthio group {preferably 1 carbon atom
~20 straight chain or branched alkylthio groups (e.g. methylthio group, octylthio group, dodecylthio group)}, acyl group (preferably straight chain or branched alkylcarbonyl group having 1 to 20 carbon atoms), acylamino group ( (preferably a linear or branched alkylcarboxamide group or benzamide group having 1 to 20 carbon atoms), a sulfonamide group (preferably a linear or branched alkylsulfonamide group having 1 to 20 carbon atoms or benzenesulfonamide group), carbamoyl group (preferably an alkylaminocarbonyl group or phenylaminocarbonyl group having 1 to 20 carbon atoms), sulfamoyl group (preferably a linear or branched alkyl group having 1 to 20 carbon atoms) aminosulfonyl group or phenylaminosulfonyl group), and 1 to 5 of these substituents are introduced into the phenyl group. Among these, preferred substituents are an alkyl group, a sulfonamide group, and a sulfamoyl group, and R ₃ is preferably at least one of these alkyl groups, sulfonamide groups, and sulfamoyl groups.
It is a phenyl group having one as a substituent. _The divalent bonding group represented by group) --SO ₂ -- group (the alkylene group is, for example, a methylene group, an ethylene group, etc.). X is preferably an -O- group. The aryl group represented by Ar in the general formula [] is
For example, phenyl group, naphthyl group, etc., preferably phenyl group. When this phenyl group has a substituent, these substituents include, for example, a halogen atom (preferably chlorine or fluorine),
Alkyl group {preferably a straight chain or branched alkyl group having 1 to 20 carbon atoms (e.g. methyl group, t
-butyl group, t-pentyl group, t-octyl group,
dodecyl group, pentadecyl group, benzyl group, phenethyl group)}, aryl group (e.g. phenyl group),
a heterocyclic group (preferably a nitrogen-containing heterocyclic group), an alkoxy group {preferably a linear or branched alkyloxy group having 1 to 20 carbon atoms (e.g., a methoxy group, an ethoxy group, a t-butyloxy group, an octyloxy group) , decyloxy group, dodecyloxy group)}, aryloxy group (e.g. phenoxy group),
Hydroxyl group, acyloxy group {preferably an alkylcarbonyloxy group (e.g. acetoxy group) or an arylcarbonyloxy group (e.g. benzoyloxy group)}, hydroxycarbonyl group, alkoxycarbonyl group (preferably a linear chain having 1 to 20 carbon atoms) or branched alkyloxycarbonyl group), aryloxycarbonyl group (preferably phenoxycarbonyl group), mercapto group, alkylthio group {preferably 1 carbon atom
~20 straight chain or branched alkylthio groups (e.g. methylthio group, octylthio group, dodecylthio group)}, acyl group (preferably straight chain or branched alkylcarbonyl group having 1 to 20 carbon atoms), acylamino group ( (preferably a straight-chain or branched alkylcarboxamide group or benzamide group having 1 to 20 carbon atoms), a sulfonamide group (preferably a straight-chain or branched alkylsulfonamide group having 1 to 20 carbon atoms or benzene) sulfonamide group), carbamoyl group (preferably an alkylaminocarbonyl group or phenylaminocarbonyl group having 1 to 20 carbon atoms), sulfamoyl group (preferably a linear or branched alkylamino group having 1 to 20 carbon atoms) sulfonyl group or phenylaminosulfonyl group), and 1 to 5 of these substituents are introduced into the phenyl group. Among these, preferred substituents are a halogen atom and a sulfonamide group, and Ar's preferred substituent is a phenyl group having at least one of these halogen atoms and a sulfonamide group as a substituent. Particularly preferred Ar is a pentafluorophenyl group. The group represented by Z in the general formula [] that can be eliminated by a coupling reaction with an oxidized product of an aromatic primary amine color developing agent is, for example, a halogen atom (for example, chlorine, bromine, fluorine, etc.), an oxygen atom, etc. or an aryloxy group, a carbamoyloxy group, a carbamoylmethoxy group, an acyloxy group, a sulfonamide group, a succinimide group, etc. in which the nitrogen atom is directly bonded to the coupling position; Specification No. 3476563,
JP-A-47-37425, JP-A-48-36894, JP-A-Sho
No. 50-10135, No. 50-117422, No. 50-130441,
No. 51-108841, No. 50-120334, No. 52-18315
No. 53-52423, No. 53-105226, and the like. Z is preferably a halogen atom, especially a chlorine atom. Specific examples of the compound represented by the general formula [] are listed below, but the compound is not limited thereto. The photographic coupler represented by the general formula [] can be easily synthesized, for example, by the following reaction formula, as detailed in the synthesis examples below. [In the formula, Z, Ar, R ₁ , R ₂ , R ₃ and X have the above-mentioned meanings. ] Synthesis Example 1 2-(2,3,4,5,6-pentafluorobenzamide)-4-chloro-5-[2-(2,
Synthesis of 4-di-t-amylphenoxy)-3-methyl-5,5-dimethylhexanamide]phenol [exemplified compound (-1)] 2-(2,3,4,5,6-pentafluorobenzamide) -4-chloro-5-aminophenol [V] 4 g and 2-(2,4-di-t-amylphenoxy)-3-methyl-5,5-dimethylhexanoyl chloride [] 5.6 g in acetonitrile 100 c.c. Add it inside and boil for 12 hours. The reaction solution was added to water, and the resulting oil was extracted with ethyl acetate. After the oil layer was separated and dried, ethyl acetate was concentrated under reduced pressure. The residue was purified using silica gel column chromatography to obtain the target compound (-1).
2.7 g of white caramel-like material was obtained. The structure was determined by NMR and MASS spectra. Synthesis Example 2 2-(2,3,4,5,6-pentafluorobenzamide)-4-chloro-5-[2-(2,
Synthesis of 4-di-t-amylphexy)-3-butenamide]phenol [exemplified compound (-5)] 2-(2,3,4,5,6-pentafluorobenzamide)-4-chloro-5-amino 4 g of phenol [V] and 2-(2,4-di-t-amylphenoxy)-3-butenoyl chloride []
4.6 g was added to 100 c.c. of acetonitrile and boiled for 6 hours. The reaction solution was added to water, and the resulting oil was extracted with ethyl acetate. After the oil layer was separated and dried, ethyl acetate was concentrated under reduced pressure. The residue was purified using silica gel column chromatography to obtain 1.8 g of a white caramel-like substance of the target compound (-5). The structure was determined by NMR and MASS spectra. Specific Uses of the Invention The photographic couplers of the invention are generally used as cyan dye-forming couplers, in which case the methods and techniques used for conventional cyan dye-forming couplers are similarly applicable. Typically,
The photographic coupler of the present invention is blended into a silver halide emulsion, and this emulsion is coated on a support to form a silver halide photographic light-sensitive material (hereinafter, the silver halide photographic light-sensitive material thus formed is referred to as the present invention). (referred to as the silver halide photographic material according to the invention). The silver halide photographic material according to the present invention can be a monochrome or multicolor silver halide photographic material. In a multicolor silver halide photographic light-sensitive material, the photographic coupler of the present invention is usually contained in a red-sensitive silver halide emulsion layer.
It may be contained in a non-sensitized emulsion or an emulsion layer sensitive to the three primary color regions of the spectrum other than red sensitivity. Each of these emulsion layers may be composed of either a single emulsion layer or a multilayer emulsion layer that is sensitive to a certain region of the spectrum. The constituent layers of the photographic material can be arranged in various orders as is known in the art. A typical multicolor silver halide photographic light-sensitive material comprises at least one red-sensitive silver halide emulsion layer containing at least one cyan dye-forming coupler (at least one of the cyan dye-forming couplers is the photographic material of the present invention). ), at least one green-sensitive silver halide emulsion layer containing at least one magenta dye-forming coupler, at least one blue-sensitive silver halide photographic material containing at least one yellow dye-forming coupler. is supported on a support. In addition to these, the silver halide photographic material can have a filter layer, an intermediate layer, a protective layer, an undercoat layer, etc. In order to incorporate the photographic coupler of the present invention into an emulsion, conventionally known methods may be followed. For example, a high boiling point organic solvent with a boiling point of 175°C or higher such as tricresyl phosphate or dibutyl phthalate or a low boiling point organic solvent such as butyl acetate or butyl propionate may be used alone, or if necessary, a mixture thereof. After the photographic couplers of the invention are dissolved alone or in combination, they are mixed with an aqueous gelatin solution containing a surfactant, then emulsified in a high speed mixer or colloid mill, and then added to silver halide to form silver halide. Emulsions can be prepared. When the photographic coupler of the present invention is added to a silver halide emulsion, it is usually 0.07 to 0.07 per mole of silver halide.
It is added in an amount of 0.7 mol, preferably 0.1-0.4 mol. The silver halide used in the silver halide emulsion used in the present invention includes silver bromide, silver chloride, silver iodobromide, silver chlorobromide, silver chloroiodobromide, etc., which are commonly used in silver halide emulsions. is included. The silver halide emulsion constituting the silver halide emulsion layer used in the present invention can be produced by various manufacturing methods including the usual manufacturing method, for example, the method described in Japanese Patent Publication No. 7772/1983 (or the method described in U.S. Pat. No. 2,592,250), that is, forming an emulsion of silver salt grains consisting of at least a portion of a silver salt whose solubility is greater than that of silver bromide, and then at least a portion of the grains of silver bromide or A method for producing a so-called conversion emulsion, such as converting it into silver iodobromide salt,
Alternatively, it can be produced by any production method such as the Lipman emulsion production method consisting of fine-grained silver halide having an average grain size of 0.1 μm or less. Furthermore, the silver halide emulsion used in the present invention is
Sulfur sensitizers, such as allylthiocarbamide, thiourea, cystine, etc., as well as selenium sensitizers, active or inactive, and reduction sensitizers, such as stannous salts, polyamines, etc., and noble metal sensitizers, such as gold sensitizers. Sensitizers, specifically potassium aurithiocyanate,
Potassium chloroaurate, 2-oresulfobenzthiazole methyl chloride, etc., or sensitizers of water-soluble salts such as ruthenium, rhodium, iridium, etc., specifically ammonium chloroparadate, potassium chloroplatinate and sodium chloroparadite. Chemical sensitization can be carried out by using these alone or in appropriate combination. Furthermore, the silver halide emulsion used in the present invention can contain various known photographic additives. For example, photographic additives such as those described in Research Disclosure, December 1978 Item 17643. In the silver halide photographic light-sensitive material according to the present invention, hydrophilic colloids used to prepare the emulsion include gelatin, derivative gelatin, graft polymers of gelatin and other polymers, proteins such as albumin and casein, and hydroxyl colloids. Examples include cellulose derivatives such as ethyl cellulose derivatives and carboxymethyl cellulose, starch derivatives, single or copolymer synthetic hydrophilic polymers such as polyvinyl alcohol, polyvinylimidazole, and polyacrylamide. The silver halide photographic material according to the present invention may be subjected to a corona discharge treatment, a fire treatment, or an ultraviolet irradiation treatment along with the emulsion layer containing the various photographic additives as described above, along with other constituent layers, as necessary. It is produced by coating on a support with a subbing layer or an intermediate layer. Advantageously used supports include, for example, baryta paper, polyethylene-coated paper, polypropylene synthetic paper, transparent supports provided with a reflective layer or in combination with a reflective material, such as glass plates, cellulose acetate, cellulose nitrate or polyethylene terephthalate. There are polyester films, polyamide films, polycarbonate films, polystyrene films, etc., and these supports are appropriately selected depending on the intended use of the silver halide photographic material. Various coating methods such as dip coating, air doctor coating, curtain coating, and hopper coating can be used to coat the emulsion layer and other constituent layers used in the present invention. It is also possible to simultaneously apply two or more layers by the methods described in US Pat. No. 2,761,791 and US Pat. No. 2,941,898. In addition, in the silver halide photographic light-sensitive material according to the present invention, it is optional to provide an intermediate layer having an appropriate thickness depending on the purpose, and furthermore, a filter layer, an anti-curl layer, a protective layer, an anti-halation layer, etc. Various layers can be used in appropriate combinations as constituent layers. Hydrophilic colloids that can be used in the emulsions described above can be similarly used as binders in these constituent layers, and various photographic materials that can be contained in the emulsion layers as described above can be used in these layers. additives can be included as well. The silver halide photographic light-sensitive material according to the present invention is used for various purposes, and exhibits excellent characteristics depending on the purpose. It can be used in photosensitive materials for X-rays and high resolution, but is particularly suitable for color photographic paper. The silver halide used in the present invention is spectral sensitized by selecting an appropriate sensitizing dye in order to impart photosensitivity in the wavelength range required for red-sensitive emulsions.
Various spectral sensitizing dyes are used, and these may be used alone or in combination of two or more. Spectral sensitizing dyes advantageously used in the present invention include, for example, US Pat. No. 2,269,234;
Same No. 2270378, Same No. 2442710, Same No. 2454620,
Typical examples include cyanine dyes, merocyanine dyes, and composite cyanine dyes as described in the specifications of No. 2776280. The color developing solution that can be used in the present invention preferably has an aromatic primary amine color developing agent as a main component. Typical examples of color developing agents include those based on p-phenylenediamine, such as diethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediamine hydrochloride, and dimethyl-p-phenylenediamine hydrochloride. Diamine hydrochloride, 2-amino-5-diethylaminotoluene hydrochloride, 2-amino-5-(N-ethyl-N-
dodecylamino)-toluene, 2-amino-5-
(N-ethyl-N-β-methanesulfonamidoethyl)aminotoluene sulfate, 4-(N-ethyl-N-β-methanesulfonamidoethylamino)
Aniline, 4-(N-ethyl-N-β-hydroxyethylamino)aniline, 2-amino-5-
(N-ethyl-N-β-methoxyethyl)aminotoluene and the like. These color developing agents may be used alone or in combination of two or more, and if necessary, may be used in combination with black and white developing agents such as hydroquinone and phenidone. Further, the color developing solution containing the above color developing agent generally contains an alkaline agent such as sodium hydroxide, ammonium hydroxide, sodium carbonate, sodium sulfate, sodium sulfite, etc., and various additives such as an alkali metal halide ( (potassium bromide, etc.) or a development regulator such as citradinic acid. Specific Effects of the Invention The photographic coupler of the present invention has excellent solubility in ordinary organic solvents used for coupler dispersion, and the resulting coupler dispersion can be used in a state where it is stored as it is or, for example, with silver halide. It has an excellent property that it does not easily precipitate even when it is contained in an emulsion layer. Furthermore, in the silver halide photographic light-sensitive material using the photographic coupler of the present invention as a cyan coupler, the spectral absorption characteristics, sensitivity, color density, and image storage properties of the cyan dye formed, especially the light,
It is excellent in terms of fastness to heat, moisture, etc. and prevention of color staining in unexposed areas, and a cyan dye image with good color development can be obtained. As described above, the photographic coupler of the present invention can be said to be a photographic coupler that exhibits excellent properties in the production and use of photographic elements including silver halide color photographic light-sensitive materials. Specific Examples of the Invention The present invention will be described in more detail with reference to specific examples below, but the embodiments of the present invention are not limited thereto. Example 1 A solubility test was conducted using the exemplary compounds of the photographic couplers of the present invention and comparative couplers shown in Table 1 below. i.e. 1g of each coupler
was added to a mixture of 1 ml of di-n-butyl phthalate and 4 ml of ethyl acetate, heated to 70°C to completely dissolve, then sealed tightly, and each sample was left to stand at 20°C to determine the state of crystal precipitation. was evaluated visually. 1 hour later, 6
The results of the evaluation after 12 hours are shown in Table 1. (In Table 1, 〇 means no precipitation, △ means slight precipitation, ×
indicates a large amount of precipitation. )

【table】

[Bleach-fix solution composition]

Ethylenediaminetetraacetate iron ammonium salt
61.0g Ethylenediaminetetraacetic acid diammonium salt
5.0g Ammonium thiosulfate 124.5g Sodium metabisulfite 13.3g Anhydrous sodium sulfite 2.7g Add water to make 1. The photographic properties of each sample obtained by the above treatment were measured. In addition, when measuring
A PDA-60 type sensitivity meter (manufactured by Konishiroku Photo Industry Co., Ltd.) was used. The results obtained are shown in Table 2 below. The sensitivity values in the table are the values of the sample with the maximum sensitivity.
Relative sensitivity was expressed as 100.

【table】

[Table] As is clear from the above table, Samples 13 and 14 using comparative couplers have problems especially in sensitivity, maximum density, and spectral absorption characteristics, but all samples using couplers of the present invention have problems in sensitivity, maximum density, and spectral absorption characteristics. It was found that the coupler of the present invention exhibits excellent performance in terms of maximum density and spectral absorption characteristics, and is a coupler with good coloring properties. Example 3 A sample having a cyan dye image was prepared in exactly the same manner as in Example 2 using the couplers of the present invention and comparative couplers shown in Table 3 below. Using this sample, experiments and studies were conducted on the light resistance, heat resistance, moisture resistance, and staining of the dye.
The results obtained are listed in Table 3 below. In the table, light resistance is measured after exposing each dye image to a xenon fade meter for 200 hours, heat resistance is measured after storage at 77°C for 2 weeks, and humidity resistance is measured at 60°C,
The residual rate at each initial concentration of 1.0 after two weeks of storage at 80% relative humidity is expressed as a percentage. In addition, stain is expressed as a percentage increase in blue density in the unexposed area of the sample subjected to the light resistance test.

[Table] As is clear from the results in the table above, the second
Comparative coupler (E) with good color development in the table
has significantly poor heat resistance and moisture resistance, comparative couplers (G) and (H) have problems with light resistance, and comparative coupler (I) has a large amount of staining, so all comparative couplers leave room for improvement. It was full of stuff. On the other hand, as shown in Table 1, the coupler of the present invention not only has excellent sensitivity and image quality, but also has excellent physical properties, that is, image preservation and stability. I found out.

Claims (1)

[Claims] 1. A photographic coupler represented by the following general formula []. General formula [] [In the formula, R ₁ represents an alkenyl group, an alkynyl group, or a branched alkyl group. R ₂ is a hydrogen atom,
Represents an alkyl group or an aryl group. R ₃ represents an aryl group. X is -O-, -S-, -SO ₂
-, (-alkylene)-O-, (-alkylene)-S-
and (--alkylene)--SO ₂ -- represents a divalent bonding group. Ar represents an aryl group. Z represents a hydrogen atom or a group capable of being eliminated by a coupling reaction with an oxidized product of an aromatic primary amine color developing agent. ].