JPH04125556A - Novel photographic coupler - Google Patents

Abstract

PURPOSE:To form cyan dye images which obviate the generation of a change in hue with heat, moisture and light by using a specific coupler. CONSTITUTION:The compd. of formula is used as the photographic coupler. In the formula, R and Y denote hydrogen or substituent; X denotes hydrogen or the substituent to be eliminated by reaction with the oxidant of a color developing agent. The more specific example of the coupler of the formula includes a compd. of which X and Y are both H and R is -NHC12H25, etc.

Description

[Detailed Description of the Invention] [Industrial Applicability] The present invention relates to a new photographic coupler used as a color photographic material, and more specifically, to a new photographic coupler that forms a dye image with poor 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 yellow images include acylacetanilide couplers, and examples of couplers used to form magenta images include pyrazolone, pyrazolobenzimidazole, and pyrazolotriazole. Alternatively, indacylon couplers are known, and phenol or naphthol couplers, for example, are generally used as couplers for forming cyan color 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, heat resistance, 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 [N].

[In the formula, R and Y represent a hydrogen atom or a substituent.

X represents a hydrogen atom or a substituent that is eliminated upon reaction with an oxidized product of a color developing agent. The present invention will be explained in more detail below.

- Formula CI] represents a hydrogen atom or a substituent, and the substituent represented by R is not particularly limited, but typically includes alkyl, aryl, anilino, acylamino, sulfonamide, alkylthio, and arylthio. , alkenyl, cycloalkyl, etc., but in addition to these, halogen atoms and 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, sulfonic acid, etc., as well as spiro compound residues, bridged hydrocarbon compound residues, and the like.

Among the substituents represented by R, 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 B 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 straight 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, alkylphosphonyl groups, aryloxyphosphonyl groups, arylphosphonyl groups, etc. ; Acyl groups include alkylcarbonyl groups, arylcarbonyl groups, etc.; carbamoyl groups include alkylcarbamoyl groups, arylcarbamoyl groups, etc.; sulfamoyl groups include alkylsulfamoyl groups,
Arylsulfamoyl group, etc.1 Acyloxy groups include alkylcarbonyloxy groups, arylcarbonyloxy groups, etc.; carbamoyloxy groups include alkylcarbamoyloxy groups, arylcarbasoyloxy groups, etc.; ureido groups include alkylureido groups, arylureido groups etc.; As the sulfamoylamino group, a 5- to 7-membered heterocyclic group is preferable, such as an alkylsulfamoylamino group or an arylsulfamoylamino group, and specifically, a 2-furyl group or a 2-thininyl group. , 2-pyrimidinyl group, 2-benzothiazolyl group, 1-pyrrolyl group, 1-tetrazolyl group, etc.; As the heterocyclic oxy group, one having a 5- to 7-membered heterocycle is preferable, for example, 3,4,5.6- Tetrahydropyranyl-2-oxy group, 1-phenyltetrazole-5-
As the heterocyclic thio group such as oxy group, a 5- to 7-membered heterocyclic thio group is preferable, such as 2-pyridylthio group, 2-benzothiazolylthio group, 2,4-difninoxy 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.; The compound residue is spiro[3,3]hebutane-
1-yl, etc.; As a bridged hydrocarbon compound residue, bicyclo[2,2,1
]hebutan-1-yl, tricyclo[3,3,1,1”
]]Decan-1-yl7,7-dimethyl-bicyclo[2
,2,1]heptane-1-yl and the like.

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, the following margins (R' and Y' are synonymous with R and Y above, Ra
and Rb represents a hydrogen atom, an aryl group, an alkyl group or a heterocyclic group. ) etc., preferably a halogen atom. Among these, particularly preferred ones represented by X are hydrogen atoms and chlorine atoms.

- In formula [1], 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 vine group that leaves under alkaline conditions as described in JP-A No. 61-228444, etc.
The substituents which are coupled off by reaction with the oxidized developing agent as described in Japanese Patent Application No. 133734 and the like are not mentioned, but Y is preferably a hydrogen atom.

Therefore, the compound of the present invention represented by the general formula [,1] is more preferably represented by the formula [II].

General formula [I]] [wherein R and X have the same meanings as R and X of the compound represented by general formula [I]. ] Next, typical compound examples of the present invention are shown below, but the present invention is not limited thereto.

Typical synthesis examples of the couplers of the present invention described above are described below.

Synthesis Example (Synthesis of Exemplified Compound 2) Exemplified Compound 2 was synthesized according to the following synthesis scheme.

(TI) I) Synthesis of Intermediate (I) Intermediate CI) is described in Journal of Pharmaceutical Sciences (J, PharLSci, ) 1968, No. 57S, p. 1044 and European Patent 3@12
It was synthesized as follows according to the method described in No. 7128.

25.0 g of 3-isopropyl-5-aminopyrazole (
0.2 mol) in water 200+nl, 95% sulfuric acid 10.33
(0.1 mol) and cooled to 0-5°C. An aqueous solution 5011 containing 15.2 g (0.22 mol) of sodium nitrite is added dropwise to this dispersion while maintaining the temperature at 0 to 5°C. Thereafter, the mixture was further stirred at this temperature for 20 minutes, and the resulting solid was collected by filtration.

This solid was further washed with water, ethanol, and ethyl acetate to obtain 17.1 g of crude intermediate (I) (containing some ethyl acetate as a solvent).

This intermediate (I) is used as it is in the next step without drying.

Synthetic intermediate (II) of the intermediate (I) is a tetrahedron letter (Tetr
ahedron Let, ters), 197
It was synthesized as follows according to the method described in 1999, No. 44, pp. 4253-4256 and European Patent No. 127028.

15.0 g of crude intermediate (1) (containing some ethyl acetate as a solvent) was dispersed in 30C++1 ethyl acetate, and 26.6 g of benzine isocyanate (0,
2 mol) was added dropwise, and the mixture was then reacted at room temperature for 30 minutes and then under boiling and reflux for 8 hours.

After the reaction is complete, insoluble matter is filtered off, the filtrate is concentrated to 100 ml, and the precipitated crystals are collected by filtration. Further recrystallization from ethyl acetate yields 11.6 g (0,043 mol) of intermediate (11).

iii) Synthetic intermediate (II) log (0,0371 mol) of Exemplary Compound 2 was dissolved in methanol, 1 g of activated carbon with 5% palladium was added,
The reaction was allowed to proceed for 5 hours at room temperature under 1 atmosphere of hydrogen.

After the reaction was completed, the catalyst was filtered off, the solvent was distilled off under reduced pressure, and the residue was recrystallized twice from ethyl acetate to obtain 4.753 (0,0265 mol) of the desired Exemplary Compound 2.

The structure of Exemplary Compound 2 was confirmed by NMRlIR and MASS.

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

The couplers of the invention typically have IX per mole of silver halide.
10-3 mol to 1 mol, preferably I x 10-2
A range of from 8 x 10'' moles can be used.

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.

This color photographic paper and other light-sensitive materials using the coupler of the present invention may be those for five-year colors or those for multiple colors. In a multicolor light-sensitive material, the coupler of the present invention may be contained in any layer, but it is usually contained in a red-sensitive silver halide emulsion layer. Multicolor photosensitive materials are spectral 3
Each of the primary color gradients 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 also be used. It is preferable that the halogen composition of silver 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 w
-(Research Dlsclosure) 1
76, 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 wood-philic colloid layer as the color developing agent itself or as its precursor,
Treatment can also be carried out using an alkaline activation bath.

After color development, a color photographic material using the coupler of the present invention is subjected to a whitening process and a fixing process. Bleaching treatment may be performed simultaneously with fixing treatment.

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

Furthermore, 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. Incidentally, the amount of the compound added is per 112 unless otherwise specified (silver halide is a silver equivalent value).

11th: Emulsion layer 1.2 g of gelatin, 0.30 g of red-sensitive silver chlorobromide emulsion (containing 96 mol% silver chloride) and 1 dioctyl phosphene
．． 3gg&:l'6 Comparative cyan coupler a9, I
A red-sensitive emulsion layer consisting of X 10-' moles.

2nd IW: Protective layer Protective layer containing 0.50 g of gelatin. In addition, as a hardening agent, 2
．． 4-dichloro-6-hydroxy-s-triazine sodium salt was added at 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 15 mff
1 ethylene glycol 15 ra
R Potassium sulfite 2.0 g Potassium bromide 0.7 g Sodium chloride 0.28 Potassium carbonate 30.0 g Hydroxylamine sulfate 3,0 g Polyphosphoric acid (TPPS)
2.5g3-methyl-4-amino-N-
Ethyl-N-(β-methanesulfonamidoethyl) Aniline sulfate 5.5g Optical brightener (4,4'-diaminostilbendisulfonic acid derivative) 1.0g Potassium hydroxide
Add 2.0g of water to bring the total volume to IIl and adjust the pH to 1.
Adjust to 0.20.

(Bleach-fix solution) Ethylenediaminetetraacetic acid ferric ammonium dihydrate 60g Ethylenediaminetetraacetic acid 3g Ammonium thiosulfate (70% solution) IDOmJl Ammonium sulfite (4
(0% solution) Adjust the pH to 7.1 with 27.5 ml of potassium carbonate or glacial acetic acid, and add water to bring the total volume to 1j2.

(Stabilizing solution) Add 1.0 g of 5-chloro-2-methyl-4-isothiazolin-3-one 10 g of ethylene glycol to I
Let's call it J2.

The concentrations of Samples 1 to 8 treated above were measured using a densitometer (Model D-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. However, the heat resistance, moisture resistance, and light resistance of the dye image are expressed as the percentage of dye remaining after heat, moisture resistance, and light resistance tests with respect to an initial density of 1.0.

Comparative coupler a Table 1 As is clear from the results in Table 1, the samples using the coupler of the present invention all have a higher dye residual rate than the samples using the comparative coupler, and have excellent heat resistance, moisture resistance, and It can be seen that it has excellent 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, unless otherwise specified, the amount of the compound added is per 1112 (silver halide is a silver equivalent value).

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.
Comparative cyan coupler b8, OX 10-' dissolved in 1 g
A red-sensitive emulsion layer consisting of moles.

No. 21: Protective layer Protective layer containing 1.5 g of gelatin, and 2 g as a hardening agent.
4-dichloro-6-hydroxy-S-triazine sodium salt was added at 0.017 g per Ig 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
1.3g Trisodium acetate nitrilotriate (monohydrate) 2.5g Potassium hydroxide 1.0g Add water to make 11, pH 1o using sodium hydroxide,
Adjust to 6.

[Bleach solution] Ethylenediaminetetraacetic acid iron ammonium salt 100.0 g Ethylenediaminetetraacetic acid diammonium salt 10.0g Ammonium bromide 150. (Add 1 g glacial acetic acid and 10.0 g water to make IIL, and adjust to p) 18.0 using aqueous ammonia.

[Fixer] Ammonium thiosulfate 175.0g Anhydrous sodium sulfite 8.6g Sodium metasulfite 2.38 Add water to make IJ2, and adjust to pH 6.0 using acetic acid.

[Stabilizing liquid] Formalin (37% aqueous solution) 1.5 Otori! Conidax
7.5@j (manufactured by Konica Corporation) Add water to make IIl.

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.

's1 layer: layer emulsion layer 1.4 g, red-sensitive silver chlorobromide emulsion (silver chloride 96
mol%) 0.5g and dibutyl phthalate 1.5
A red-sensitive emulsion layer consisting of 9.1×10 −4 mol of the coupler shown in Table 3 dissolved in g.

2nd layer: Protective layer A protective layer containing 0.5 g of gelatin, and 2.0 g as a hardening agent.
0.017 g of 4-dichloro-6-hydroxy-5-)-riazine sodium salt was added 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 processing step Time Temperature - Development 6 minutes 38℃ Water washing 2 minutes 38℃
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 [inversion Vi] g 2.5g 1.2g 1000 ■Onitrillotrimethylenephosphonic acid, hexasodium salt 3g stannous chloride (dihydrate) Igp-aminophenol 0.1g Sodium hydroxide
5g ice vinegar @
15 Add tan water
1000 sR [Color developer] Sodium tetrapolyphosphate 2g Sodium sulfite 7g Sodium tertiary phosphate (decahydrate) 36g Potassium bromide
1g potassium iodide (0.1% solution)
90 yaR sodium hydroxide
3g Citrazic acid 1.
Add 5 g N-ethyl-N-(β-methanesulfonamidoethyl)-3-methyl-4-aminoaniline sulfate 11 g ethylenediamine 3 g water
1000 all [Adjustment solution] Sodium sulfite Sodium ethylenediaminetetraacetate (dihydrate) Add thioglycerin glacial acetic acid water [Bleach solution] Sodium ethylenediaminetetraacetate (dihydrate) Iron(III) ethylenediaminetetraacetate Ammonium (dihydrate) ) Add potassium bromide water [Fixer] Ammonium thiosulfate Sodium sulfite Add sodium bisulfite water [Stabilizer] g O, O+j 1j 1000 tan 2.0g 120.0g 100.0g 1000 ml 80.0g 5. 0g 5.0g 1000 mj Formalin (37% by weight) 5.0+1 Konidax (manufactured by Konica Corporation) 5.0mj Add water 1000++# For each sample treated above, heat resistance of the dye image was determined in the same manner as in Example 2.・We investigated moisture resistance and light resistance. 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 appears to be sturdy.

[Effect of the invention] Dye images formed from the couplers of this invention can be produced by thermal, It was found to be robust to humidity and light.

Claims (1)

[Claims] A photographic coupler represented by the general formula [I]. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [In the formula, R and Y represent a hydrogen atom or a substituent. X represents a hydrogen atom or a substituent that is eliminated upon reaction with an oxidized product of a color developing agent. ]