JPH0285851A - Novel coupler for photography - Google Patents

Abstract

PURPOSE:To form a cyan pigment image not causing a change in the hue due to heat, moisture and light by using a specified coupler. CONSTITUTION:A pigment image hardly affected by heat, moisture and light can be formed by using a specified coupler represented by formula I. In the formula I, each of R1, R2, R3 and Y is H, a group such as alkyl, aryl, anilino or cycloalkyl, a residue of a spiro compd., an org. residue of a hydrocarbon compd., etc., the alkyl is preferably 1-32C alkyl and may be straight chain or branched alkyl, R2 and R3 may bond to each other to form a ring and X is H or a substituent which is released by a reaction with the oxidized product of a color developing agent.

Description

Detailed Description of the Invention [Field of Application in Industry A] The present invention relates to a novel photographic coupler used as a color photographic material, and more specifically, to a color photographic coupler that forms a dye image with excellent fastness to heat, humidity, and light. Regarding photographic couplers.

[Background of the Invention] After a silver halide photographic material is exposed to light and then subjected to color development processing, the oxidized aromatic primary amine color developing agent and the dye-forming coupler react in the exposed area. Pigments are produced and a color image is formed.

Generally, this photographic method uses a subtractive color reproduction method to form yellow, magenta, and cyan color images.

Examples of photographic couplers used to form the yellow image include acylacetanilide couplers, and examples of couplers used to form magenta images include pyrazolone, pyrazolobenzimidazole, pyrazolotriazole, and indasilone. For example, phenol or naphthol couplers are commonly used as couplers for forming cyan images.

It is desired that the dye image obtained in this way does not change color or fade even if it is exposed to light for a long time or stored under high temperature and high humidity.

However, phenolic couplers and naphthol couplers, which have been studied as couplers for forming cyan dyes, have poor spectral absorption characteristics, Wf thermal properties, moisture resistance, light resistance, etc. of the formed cyan dye images. This is still unsatisfactory, and various proposals have been made to improve this, including devising substituents, but a compound that satisfies all of these has not yet been obtained.

As a result of further research into the above points, the present inventors discovered a photographic coupler that forms a cyan dye image that does not change in hue due to heat, humidity, or light.
The present invention has now been completed.

[Object of the Invention] The first object of the present invention is to provide a novel photographic coupler that can be used as a color photographic material.

A second object of the present invention is to provide a photographic coupler that forms a cyan dye image that does not change in hue due to heat, humidity, or light.

[Structure of the Invention] The above objects of the present invention have been achieved by a photographic coupler represented by the general formula [1].

[In the formula, R1, R2, R5 and Y represent a hydrogen atom or a substituent, and R2 and R8 may be combined to form a ring. X represents a hydrogen atom or a substituent that is eliminated upon reaction with an oxidized product of a color developing agent. ] Hereinafter, the present invention will be explained in more detail.

- R1, R2 and R3 in formula [I] represent a hydrogen atom or a substituent, and the substituents represented by R1, R2 and R3 are not particularly limited, but typically include alkyl, aryl, anilino, acylamino , sulfonamide, alkylthio, arylthio, alkenyl, cycloalkyl, etc.; in addition, halogen atoms, cycloalkenyl, alkynyl, heterocycle, sulfonyl, sulfinyl, phosphonyl, acyl, carbamoyl, sulfamoyl, cyano, alkoxy , sulfonyloxy, aryloxy, heterocyclicoxy, siloxy,
Acyloxy, carbamoyloxy, amino, alkylamino, imide, ureido, sulfamoylamino, alkoxycarbonylamino, aryloxycarbonylamino, alkoxycarbonyl, aryloxycarbonyl, heterocyclic thio, thioureido, carboxy, hydroxy, mercapto, nitro, sulfone Also included are 8 groups such as acids, spiro compound residues, bridged hydrocarbon compound residues, and the like.

Among the substituents represented by R, R, and R3, the alkyl group preferably has 1 to 32 carbon atoms, and may be linear or branched.

As the aryl group, a phenyl group is preferred.

Examples of the acylamino group include an alkylcarbonylamino group and an arylcarbonylamino group.

Examples of the sulfonamide group include an alkylsulfonylamino group and an arylsulfonylamino group.

Examples of the alkyl component and aryl component in the alkylthio group and arylthio group include the alkyl group and aryl group represented by R1, R2 and R5 above.

The alkenyl group preferably has 2 to 32 carbon atoms, and the cycloalkyl group preferably has 3 to 12 carbon atoms, particularly 5 to 7 carbon atoms, and the alkenyl group may be linear or branched.

The cycloalkenyl group has 3 to 12 carbon atoms, especially 5
-7 is preferred.

Sulfonyl groups include alkylsulfonyl groups, arylsulfonyl groups, etc.; sulfinyl groups include alkylsulfinyl groups, arylsulfinyl groups, etc.; phosphonyl groups include alkylphosphonyl groups, alkoxyphosphonyl groups, aryloxyphosphonyl groups, and arylphosphonyl groups. Acyl groups include alkylcarbonyl groups, arylcarbonyl groups, etc.; carbamoyl groups include alkylcarbamoyl groups, arylcarbamoyl groups, etc.; sulfamoyl groups include alkylsulfamoyl groups,
Arylsulfamoyl groups, etc.; Acyloxy groups include alkylcarbonyloxy groups, arylcarbonyloxy groups; carbamoyloxy groups include alkylcarbamoyloxy groups, arylcarbamoyloxy groups, etc.; ureido groups include alkylureido groups, arylureido groups, etc. ; As the sulfamoylamino group, an alkylsulfamoylamino group, an arylsulfamoylamino group, etc.; as a heterocyclic group, a 5- to 7-membered one is preferable, and specifically, a 2-furyl group, a 2-thienyl group , 2-pyrimidinyl group, 2-benzothiazolyl group, 1-pyrrolyl group, 1-tetrazolyl group ring; The heterocyclic oxy group preferably has a 5- to 7-membered heterocycle, for example, 3゜4.5.6- Tetrahydrobilanyl-2-oxy group, 1-phenyltetrazole-5-
Oxy group etc.: The heterocyclic thio group is preferably a 5- to 7-membered heterocyclic thio group, such as 2-pyridylthio group, 2-benzothiazolylthio group, 2,4-diphenoxy-1,3,5-triazole -6 monothio group, etc.; Siloxy group includes trimethylsiloxy group, triethylsiloxy group, dimethylbutylsiloxy group, etc.; imide group includes succinimide group, 3-heptadecylsuccinimide group, phthalimide group, glutarimide group, etc. ; As a spiro compound residue, spiro[3,3]hebutane-
1-yl, etc.; As a bridged hydrocarbon compound residue, bicyclo[2,2,l
] heptan-1-yl, tricyclo[3,3,1,1”
]]Decan-1-yl7,7-dimethyl-bicyclo[2
, 2,11-butan-1-yl and the like.

Among the above substituents, R2 and R3 preferably represent, for example, an alkyl group, an aryl group, a carboxyl group,
Examples include polygroups such as oxycarbonyl group, cyan group, hydroxy group, alkylthio, aryloxy group, amino group, amide group, and sulfonamide group, hydrogen atom, halogen atom, and the like.

Furthermore, R7 and R5 may be combined with each other to form a ring, and the ring may be a saturated or unsaturated 5-membered ring, a 6-membered ring, or a 7-membered ring.
A membered ring, an 8-membered ring, etc. are preferred, and specific examples include benzene, pyridine ring, and quinoline ring.

The above group may further have a substituent such as a long-chain hydrocarbon group or a diffusion-resistant group such as a polymer residue.

Examples of the group that is released by reaction with the oxidized product of the color developing agent represented by X include halogen atoms (chlorine atom, bromine atom, fluorine atom, etc.), alkoxy, aryloxy, heterocyclic oxy, acyloxy, sulfonyloxy, alkoxy Carbonyloxy, aryloxycarbonyl, alkyloxalyloxy, alkoxyoxalyloxy, alkylthio, arylthio, heterocyclic thio, alkyloxythiocarbonylthio, acylamino, sulfonamide, nitrogen-containing heterocycle bonded via N atom, alkyloxycarbonylamino , aryloxycarbonylamino,
carboxyl, (R' is synonymous with the above R1, lh and R3, 2'
has the same meaning as Z above, and Ra and Rb represent a hydrogen atom, an aryl group, an alkyl group, or a heterocyclic group. ), preferably a halogen atom. Among these, particularly preferred ones represented by X are hydrogen atoms and chlorine atoms.

- In formula [I], Y represents a hydrogen atom or a substituent, and preferred examples of the substituent represented by Y include those that are eliminated from the compound of the present invention after the compound reacts with the oxidized developing agent. However, for example, the substituent represented by Y may be a group that can be separated under alkaline conditions as described in JP-A No. 61-228444, etc.
Examples include substituents that are coupled off by reaction with an oxidized developing agent as described in No. 133734, etc., and preferably Y is a hydrogen atom.

Therefore, the compound of the present invention represented by the formula [■] is:
More preferably, it is represented by the following formula [I].

l'+3 [wherein R, %R2, R5 and X have the same meanings as R1%R2, R5 and X of the compound represented by the general formula [I]. ] Next, typical compound examples of the present invention are shown below, but the present invention is not limited thereto.

Methods for synthesizing the compounds used in the present invention are known, for example, as described in the Journal of Heterocyclic Chemistry (J, Heterocycle, Chew).
.

The method described in 1976, Vol. 13 (3), pp. 615-617 can be cited, and as an example thereof, an example of synthesis of the compound of the present invention is shown below.

Synthesis Example (Synthesis of Compound 14) △ Compound 14 [Synthesis of Compound a] 9.7 g (0.1 mol) of 3-amino-5-methylpyrazole, 22 g (0.1 mol) of benzoylmethanesulfonyl chloride
, 1 mol) and 12 g (o, 12 mol) of triethylamine were added to chloroform at 500 mA and heated under reflux for 5 hours. After distilling off the chloroform, 500mj! The mixture was boiled and refluxed with water for 10 minutes. After cooling, this solution was made strongly alkaline with a 20% sodium hydroxide solution, and then centrifugal flow was continued for 30 minutes. Acidify with concentrated hydrochloric acid, collect the precipitated crystals by filtration, recrystallize twice with methanol containing a small amount of water,
1 g (0.04 mol) of compound a was obtained.

[Synthesis of compound 14] 8.4 g (0.03 mol) of compound a was treated at 180° C. to 200° C. for 15 minutes without solvent and in a nitrogen gas atmosphere,
After cooling, the crystals were recrystallized twice from ethanol to yield 2.9 g (
0,011 mol) of Compound 14 was obtained.

Compound 14 by mass spectrum and NMR spectrum
The structure of was confirmed.

Other compounds used in the present invention can also be synthesized according to the above synthesis method.

The couplers of the invention typically have IX per mole of silver halide.
10-1 mole, preferably 1 x 10-2
It can be used in the range of mol to 8 x 10-' mol.

The coupler of the present invention can also be used in combination with other types of cyan couplers.

The methods and techniques used in conventional dye-forming couplers apply similarly to the couplers of the invention.

The coupler of the present invention can be used as a material for forming color photographs by any coloring method, and specific examples include external coloring method and internal coloring method. When used as an external coloring method, the coupler of the present invention can be dissolved in an alkaline aqueous solution or an organic solvent (for example, alcohol) and added to a developing solution.

When the coupler of the present invention is used as a material for forming a color photograph by an internal coloring method, the coupler of the present invention is incorporated into a photographic light-sensitive material.

Typically, a method is preferably used in which the coupler of the present invention is blended into a silver halide emulsion and this emulsion is coated on a support to form a color light-sensitive material. The coupler of the present invention is used, for example, in color photographic materials such as color negative and positive films and color photographic paper.

The photosensitive materials using the coupler of the present invention, including this color photographic paper, may be monochromatic or multicolor. In multicolor photosensitive materials, the coupler of the present invention may not be contained in any layer. However, it is usually contained in the red-sensitive silver halide emulsion layer. Multicolor photosensitive materials are spectral 3
Each of the primary color regions has a photosensitive dye image forming unit. Each building block can consist of a single or multiple emulsion layer sensitive to a certain region of the spectrum. The constituent layers of the photosensitive material, including the layers of image-forming units, can be arranged in various orders as is known in the art.

A typical multicolor light-sensitive material is a cyan dye image-forming unit consisting of at least one red-sensitive silver halide emulsion layer containing at least one cyan coupler (at least one of the cyan couplers is the cyan coupler of the present invention). ), a magenta dye image-forming unit consisting of at least one green-sensitive silver halide emulsion layer containing at least one magenta coupler, at least one blue-sensitive silver halide emulsion layer containing at least one yellow coupler. It consists of a yellow dye image-forming structural unit consisting of an emulsion layer supported on a support.

The photosensitive material may contain additional layers such as filter layers, interlayers,
It can have a protective layer, an undercoat layer, etc. In order to incorporate the coupler of the present invention into an emulsion, a conventionally known method may be followed. For example, the coupler of the present invention may be added to a high boiling point organic solvent having a boiling point of 175°C or higher such as tricresyl phosphate or dibutyl phthalate, or a low boiling point solvent such as butyl acetate or butyl propionate, or a mixture thereof as necessary. alone or in combination, mixed with an aqueous gelatin solution containing a surfactant, then emulsified in a high-speed rotary mixer or colloid mill, and then added to silver halide to obtain the halogenated compound used in the present invention. Silver emulsions can be prepared.

Silver halide compositions preferably used in the light-sensitive material using the coupler of the present invention include silver chloride, silver chlorobromide, and silver chloroiobromide. Furthermore, a combination mixture such as a mixture of silver chloride and silver bromide may be used. That is, when a silver halide emulsion is used for color photographic paper, particularly fast developability is required, so it is preferable that the halogen composition of the silver halide contains chlorine atoms, and at least 1%.
It is particularly preferable to use silver chloride, silver chlorobromide or silver chloroiodobromide containing silver chloride.

The silver halide emulsion is chemically sensitized by conventional methods. Furthermore, it can be optically sensitized to a desired wavelength range.

Silver halide emulsions are used during the manufacturing process of photosensitive materials, during storage,
Alternatively, compounds known as antifoggants or stabilizers in the photographic industry may be added for the purpose of preventing fog during photographic processing and/or keeping photographic performance stable.

In the color photosensitive material using the coupler of the present invention, color antifoggants, dye image stabilizers, ultraviolet inhibitors, antistatic agents, matting agents, surfactants, etc., which are normally used in photosensitive materials, can be used. .

Regarding these, for example, Research Disclosure 1
78%, pages 22-31 (December 1978).

An image can be formed on a color photographic material using the coupler of the present invention by subjecting it to a color development treatment known in the art.

The color photographic material using the coupler according to the present invention is
A color developing agent is contained in the hydrophilic colloid layer as the color developing agent itself or as a precursor thereof,
Treatment can also be carried out using an alkaline activation bath.

A color photographic material using the coupler of the present invention is subjected to a bleaching treatment and a fixing treatment after color development. Bleaching treatment may be performed simultaneously with fixing treatment.

After the fixing process, a washing process is usually performed.

Further, a stabilization treatment may be performed as an alternative to the water washing treatment, or both may be used in combination.

[Example] Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 A red-sensitive color photosensitive material sample 1 was prepared by sequentially coating the following layers on a paper support laminated on both sides with polyethylene from the support side. Note that the amount of the compound added is per 1 m'' unless otherwise specified (silver halide is a silver equivalent value).

1st layer: Emulsion layer Comparative cyan coupler a9, I
Red-sensitive emulsion layer consisting of IO"' moles.

Second layer: Protective layer Protective layer containing 0.50 g of gelatin. In addition, as a hardening agent, 2
．． 4-dichloro-6-hydroxy-5-triazine sodium salt was added at a concentration of 0.017 g per gram of gelatin.

Next, Samples 2 to 8 of the present invention were prepared in exactly the same manner as in Sample 1, except that comparative coupler a was replaced with the coupler shown in Table 1 (the amount added was the same molar amount as comparative coupler a).

Samples 1 to 8 obtained above were each subjected to wedge exposure according to a conventional method, and then developed in the next step.

(Development process) Color development 38℃ 3 minutes 30 seconds bleach fixing
Stabilization treatment at 38°C for 1 minute and 30 seconds/or washing treatment at 25°C to 30°C for 3 minutes Drying at 75°C to 80°C for 2 minutes The composition of the treatment liquid used in each treatment step is as follows.

(Color developer) Benzyl alcohol Ethylene glycol Potassium sulfite Potassium bromide Sodium chloride Potassium carbonate Hydroxylamine sulfate Polyphosphoric acid (TPPS) Aniline sulfate 15 mi+ 15 mj! 2.0g Q,73 0.2g 30.0g 3,Og 2.5g 5.5g Fluorescent brightener (4,4'-diaminostilbendisulfonic acid derivative) Add potassium hydroxide water and take out the total amount.

(Bleach-fix solution) 1, H 1.0g 2.0g Adjust to 10.20 Ferric ammonium ethylenediaminetetraacetate dihydrate Ammonium thiosulfate ethylenediaminetetraacetate (70% solution) 100mj Ammonium sulfite (40% solution) 27 Adjust the pH to 7.1 with .5mj potassium carbonate or glacial acetic acid, and add water to bring the total volume to IIL.

(Stabilizing liquid) 5-chloro-2-methyl-4-isothiazolin-3-one 1.0 g Ethylene glycol 10 g Add water to 1
Let it be fL.

The concentrations of samples 1 to 8 treated above were measured using a densitometer (model KD-7 manufactured by Konica Corporation), and each of the above-treated samples was measured at high temperature (60°C, 80% RH).
) The dye image was left in an atmosphere for 14 days, and the heat resistance and moisture resistance of the dye image were examined.

Further, each sample was irradiated with a xenon fade meter for 10 days, and then the density was measured to examine light resistance. The results are shown in Table 1, provided that the heat resistance, humidity resistance and light resistance of the dye image are expressed as the percentage of dye remaining after the heat resistance, humidity resistance and light exposure tests with respect to the initial density of 1.0.

Comparative coupler a Csl(++(t) 2 Table 1 As is clear from the results in Table 1, the samples using the coupler of the present invention had a lower dye residual rate than the samples using the comparative coupler. It can be seen that the material has high heat resistance, excellent heat resistance, moisture resistance, and light resistance, and is robust.

Example 2 A red-sensitive color photosensitive material (sample 9) was prepared by sequentially coating the following layers on a subbed triacetate film from the support side. Incidentally, the amount of the compound added is per 1 m2 unless otherwise specified (silver halide is a value in terms of silver).

1st layer: Emulsion layer 1.4 g of gelatin, 1.5 g of red-sensitive silver iodobromide emulsion (containing 4 mol% silver iodide) and 1.5 g of tricresyl phosphate.
A red-sensitive emulsion layer consisting of 8 moles of comparative cyan coupler b, OXl dissolved in 1 g.

2nd layer: Protective layer A protective layer containing 1.5 g of gelatin, and 2.0 g as a hardening agent.
4-dichloro-6-hydroxy-s-triazine sodium salt was added in an amount of 0.017 g per gram of gelatin.

Next, for sample 9, the comparison cyan coupler b is shown in Table-2.
The coupler shown in (the amount added is the same molar amount as comparative coupler b)
Samples 10 to 10 of the present invention were prepared in exactly the same manner except that
No. 16 was produced.

The obtained film samples were wedge exposed in a conventional manner and color developed according to the color processing steps described below.

Comparative coupler b [Processing process] (Processing temperature 38°C) Processing time Color development 3 minutes 15 seconds Bleaching
Wash with water for 6 minutes and 30 seconds
Fixed for 3 minutes and 15 seconds
Wash with water for 6 minutes and 30 seconds
Stabilized for 3 minutes and 15 seconds
Drying for 1 minute and 30 seconds The composition of the treatment liquid used in each treatment step is as follows.

[Color developer] 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline sulfate 4.75 g Anhydrous sodium sulfite 4.25 g Hydroxyamine 1/2 sulfate 2.0 g Anhydrous carbonate Potassium 37.5 g Sodium bromide 1.3 g Trisodium nitrilotriacetic acid (monohydrate) 2.5 g Potassium hydroxide 1.0 g Add water to make IIL, use sodium hydroxide p) 11
Adjust to 0.6.

[Bleach solution] Iron ethylenediaminetetraacetate ammonium salt Ethylenediaminetetraacetic acid 2 ammonium salt ammonium bromide glacial acetic acid Add water and IJZ Adjust the pH to 6.0.

100.0g 10.0g 150.0-g 1Q, Q3 Using ammonia water [Fixer] Ammonium thiosulfate 175.0g Anhydrous sodium sulfite 8.6g Sodium metasulfite 2.3g Add water and bring to 1°C. Adjust the pH to 6.0 using acetic acid.

[Stabilizing liquid] Formalin (37% aqueous solution) 1.5m
1) Conidax 7.5m
i+ (manufactured by Konica Corporation) Add water to make IR.

For samples 9 to 16 treated above, the transmission density was measured using a densitometer (Model D-7R manufactured by Konica Corporation), and each of the treated samples was measured at high temperature (60℃, 8℃).
The dye image was left in an atmosphere (0% RH) for 14 days, and the heat resistance and moisture resistance of the dye image were examined.

In addition, each sample was irradiated with a xenon fade meter for 10 days to examine light resistance. The results are shown in Table 2, provided that the heat resistance, humidity resistance and light resistance of the dye image are expressed as the percentage of dye remaining after the heat resistance, humidity resistance and light resistance tests with respect to the initial density of 1.0.

Table 2 As is clear from the results in Table 2, the samples using the coupler of the present invention had a higher dye residual rate than the samples using the comparative coupler, and had poor heat resistance, moisture resistance, and light resistance. It can be seen that it is excellent and robust.

Example 3 The following layers were sequentially coated on a triacetyl cellulose film support from the support side to prepare red-sensitive color reversal photographic materials 17 to 22 containing the couplers shown in Table 3.

1st layer: Emulsion layer 1.4 g of gelatin, 0.5 g of red-sensitive silver chlorobromide emulsion (containing 96 mol% silver chloride) and 1.5 g of dibutyl phthalate.
A red-sensitive emulsion layer consisting of 9.1×10 −4 mol of the coupler shown in Table 3 dissolved in .

2nd layer: Protective layer A protective layer containing 0.5 g of gelatin, and 2.0 g as a hardening agent.
4-dichloro-6-hydroxy-5-triazine sodium salt was added in an amount of 0.017 g per gram of gelatin.

The samples obtained above were each subjected to wedge exposure according to a conventional method, and then developed in the next step.

[Reversal process] Process Time Temperature - Development 6 minutes 38℃ Water washing 2 minutes 38℃ Incubation
Transfer 2 minutes 38℃ Color development 6 minutes 38℃ Adjustment 2 minutes 38℃ bleaching
White 6 minutes 38℃
Fixation 4 minutes 38℃ water
Wash 4 minutes at 38℃
Dry at 38℃ for 1 minute.
The following composition is used for the room temperature treatment solution.

[First developer] Sodium tetrapolyphosphate Sodium sulfite Hydroquinone monosulfonate Sodium carbonate (monohydrate) 1-Phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone Potassium bromide Potassium thiocyanate Potassium iodide (0.1% solution) Add water and g 2.5g 1.28 mR 1000l1lR [Reverse solution] Nitrilotrimethylenebosphonic acid, hexasodium salt, stannous chloride (dihydrate), p-aminophenol, sodium hydroxide ice Add acetic acid water [color developer] Sodium tetrapolyphosphate Sodium sulfite Sodium tertiary phosphate (12 hydrate) Potassium bromide Potassium iodide (0.1% solution) Sodium hydroxide Citrazine acid-4-aminoaniline・Add sulfate ethylenediamine water g g 0.1 g g 15 m 1000 mR g g 6 g g 90 InN g 45 g g [Adjustment? Night] Sodium sulfite Sodium ethylenediaminetetraacetate (dihydrate) Add thioglycerin glacial acetic acid water [Bleach solution] Sodium ethylenediaminetetraacetate (dihydrate) Iron ethylenediaminetetraacetate (Ill) Ammonium (dihydrate) Potassium bromide Add water [Fixer] Ammonium thiosulfate Sodium sulfite Sodium bisulfite Add water [Stabilizer] Formalin (37% by weight) g O, 4mj! 3 mj! For each sample treated above In the same manner as in Example 2, the heat resistance, moisture resistance, and light resistance of the dye image were examined. The results are shown in Table-3.

Table 3 As is clear from Table 3, the samples using the coupler of the present invention all had higher dye residual rates and superior heat resistance, moisture resistance, and light resistance compared to samples using the comparative coupler. It can be seen that it is robust.

Effects of the Invention Dye images formed from the couplers of the invention were found to be robust to heat, humidity and light.

Claims (1)

[Claims] A photographic coupler represented by the general formula [I]. General formula [I] ▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R_1, R_2, R_3 and Y represent a hydrogen atom or a substituent, and R_2 and R_3 may be combined to form a ring. X represents a hydrogen atom or a substituent that is eliminated upon reaction with an oxidized product of a color developing agent. ]