EP0232101B1

EP0232101B1 - Light-sensitive silver halide color photographic material

Info

Publication number: EP0232101B1
Application number: EP19870300640
Authority: EP
Inventors: Yamashita Kiyotoshi; Watanabe Yoshikazu
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 1986-01-25
Filing date: 1987-01-26
Publication date: 1994-03-23
Anticipated expiration: 2007-01-26
Also published as: JPS62253170A; DE3789394D1; EP0232101A2; EP0232101A3

Description

This invention relates to a light-sensitive silver halide photographic material, and, particularly, to a light-sensitive silver halide color photographic material having improved sharpness and graininess.
In recent years, image quality of light-sensitive silver halide photographic materials (hereinafter "light-sensitive material") has been remarkably improved, but sharpness and graininess can not necessarily be said to have been sufficiently improved. In particular, in a print enlarged from a small format (such as 110 film and disc film) negative type color film, coarseness in images (or graininess) and also poor sharpness make the level of image quality of the print extremely low. This is because the graininess and the sharpness of the negative type films have not been made suitable for high magnification prints.
Conventionally, there have been known a variety of techniques for improving sharpness. They include a technique for preventing light scattering, and a technique for improving the edge effect.
The latter technique includes a method employing a so-called DIR coupler, and a method employing an unsharp mask. Of these, the method employing an unsharp mask may sometimes cause the sharpness to be lowered and the graininess to be deteriorated so as to give a limit in practical use. The method employing the DIR coupler is well known, and useful DIR couplers include the compounds disclosed in Japanese Patent Publication No. 34933/1980, Japanese Unexamined Patent Publication No. 93344/1982, U.S. Patents No. 3,227,554, No. 3,615,506, No. 3,617,291 and No. 3,701,783. However, when the edge effect is strengthened by using the DIR couplers, the MTF (modulation transfer function) is improved at a lower frequency region, but the improvement of MTF at a higher frequency region, which is necessary for achieving a high enlargement magnification, can not be expected, because of accompanying undesirable side effects such as the lowering of sensitivity and the lowering of density. It is possible to minimize the fall of sensitivity and density if DIR couplers such as diffusible DIR and timing DIR couplers having so-called long distance effectiveness are used, but MTF may be improved at a region shifted to a lower frequency, and there will not be so great an improvement in sharpness at the high enlargement magnification.
On the other hand, as a technique for preventing light scattering, it has been known to add a coloring substance, decrease the amount of silver halide, or make the film thinner. Drastic reduction of coated silver weight may decrease the number of color developing spots and cause deterioration of graininess. It is also possible to reduce the amount of gelatin, coupler or coupler solvent in a coating solution, but any of these measures may cause deterioration of coating performance or lowering of color density and so have their own limits.
Attempts have been made to suppress light scattering and increase sharpness by adding a colouring substance as mentioned above, but no satisfactory result has occurred.
DE 2643965 discloses a light-sensitive colour photographic material comprising 5-pyrazolone type magenta couplers which are said to produce sufficient colour correction effect without adversely affecting the graininess of the image, even when the developing time is shorter.
In recent years, pyrazolotriazole type couplers have attracted notice as magenta couplers. Such couplers show not only so little secondary absorption as to be advantageous in the colour reproducibility, but also such good colour developing performance as to need less coupler. Accordingly, they have been found to be very advantageous for making a film thinner and effective for improving sharpness.
However, it was found that the pyrazolotriazole type couplers can not be expected to have an improving effect in respect of graininess.
Accordingly, in the system employing the pyrazolotriazole type couplers, attempts have been made to develop a technique for improving graininess.
An object of this invention is to provide a light-sensitive silver halide colour photographic material which has not only remarkably improved colour reproducibility and sharpness, but also improved graininess.
According to this invention there is provided a light-sensitive silver halide colour photographic material having at least one mono-disperse light-sensitive silver halide emulsion layer containing a pyrazolotriazole type magenta coupler and a coloured magenta coupler, wherein the layer containing the pyrazolotriazole type magenta coupler and the coloured magenta coupler comprises 17 mole % or more of said coloured magenta coupler based on the amount of all couplers in said layer.
The pyrazolotriazole type magenta coupler according to this invention may preferably include the compound represented by Formula (I) or (II) shown below.
In the above Formula (I) and (II), R₁ and R₂ each represent an optionally substituted group, an aryl group or a hetero ring, and these alkyl group, aryl group and hetero ring may be linked through an oxygen atom, a nitrogen atom or an sulfur atom. The above alkyl group, aryl group and hetero ring may also be linked through a linking group selected from the following groups: acylamino, carbamoyl, sulfonamide, sulfamoylcarbonyl, carbonyloxy, oxycarbonyl, ureido, thioureido, thioamide, sulfone and sulfonyloxy.
The alkyl group represented by R₁ or R₂ includes a straight chain or branched alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, propyl, i-propyl, sec-butyl, n-butyl, t-butyl, n-octyl, t-octyl, dodecyl, octadecyl). These groups may further have a substituent (for example, a halogen atom, nitro, cyano, alkoxy, aryl, oxy, amino, acylamino, carbamoyl, sulfonamide, sulfamoyl, imide, alkylthio, arylthio, aryl, alkoxycarbonyl and acyl). Specifically, the group may include chloromethyl, bromomethyl, trichloromethyl, ,8-nitroethyl, o-cyanobutyl, methoxymethyl, ethoxyethyl, phenoxyethyl, N-methylaminoethyl, dimethylaminobutyl, acetaminoethyl, benzoylamino, propyl, ethyl carbamoylethyl, methanesulfonamide ethyl, ethyl thioethyl, p-methoxyphenylthiomethyl, phenylmethyl, p-chlorophenylmethyl, naphthylethyl, ethoxycarbonylethyl, acetylethyl.
The aryl group includes a phenyl group and a naphthyl group, and may have a substituent including the substituents for the above alkyl group.
The hetero ring includes a 5- or 6-membered ring having at least any one of a nitrogen atom, an oxygen atom and a sulfur atom, and may be aromatic or may not be aromatic. For example, it includes pyridyl, quinolyl, pyrolyl, morpholyl, furanyl, tetrahydrofuranyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl, imidazolyl, thiadiazolyl. These may also have a substituent corresponding to the substituents for the alkyl group.
R₁ and R₂ may be linked to each other to form a hydrocarbon ring (for example, cyclopropyl, cyclopentyl, cyclohexyl, cyclohexenyl).
The compound wherein the alkyl group, the aryl group or the hetero ring represented by R₁ or R₂ is linked to each other through the linking group mentioned above or the nitrogen atom, oxygen atom or sulfur atom may include, for example, the following:

Here, R_2' represents an alkyl group, an aryl group or a hetero ring; R_2'' and R_2''' each represent a hydrogen atom, an alkyl group, an aryl group or a hetero ring.
When the hetero ring group is a pyrazolotriazole type compound, a bis type pyrazolotriazole type compound is formed, which is of course a magenta coupler included in this invention.
Examples of R₁ and R₂ shown in the above formulas are shown below:
In the above formulas, Z represents a hydrogen atom or a group which may be eliminated when a dye is formed through coupling with an oxidized product of an aromatic primary amine color developing agent.
Specifically, it may include, for example, a halogen atom, an alkoxy group, an aryloxy group, an acyloxy group, an arylthio group, an alkylthio group, and a
(wherein Z₂ represents a group of atoms necessary for the formation of a 5- or 6-membered ring, said atoms being carbon, oxygen, nitrogen or sulfur atoms together with the nitrogen atom) group.
Examples thereof are shown below:

Halogen atoms: Chlorine, bromine and fluorine.
Alkoxy group: An ethoxy group, a benzyloxy group, a methoxyethyl carbamoylmethoxy group, a tetradecyl carbamoylmethoxy group.
Aryloxy group: A phenoxy group, a 4-methoxyphenoxy group, a 4-nitrophenoxy group.
Acyloxy group: An acetoxy group, a myristoyloxy group, a benzoyloxy group.
Arylthio group: A phenylthio group, a 2-butoxy-5-octylphenylthio group, a 2,5-dihexyloxyphenylthio group.
Alkylthio group: A methylthio group, an octylthio group, a hexadecylthio group, a benzylthio group, a 2-(diethylamino)ethylthio group, an ethoxycarbonylmethylthio group, an ethoxyethylthio group, a phenox- yethylthio group.
group: wherein Z₂ represents a group of atoms which completes a 5- or 6- membered ring containing at least one carbon, nitrogen, oxygen or sulfur together with the nitrogen; Examples of the group include A pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group.

The group represented by
may include, for example, the following:

Exemplary compounds represented by Formula (I) or (II) are shown below:
The colored magenta coupler according to this invention preferably includes the compound represented by the following formula:

Formula (III): Cp-N = N-R₃

In the formula, Cp represents a magenta coupler residual group (provided, however, that the azo group is attached to an active site of the magenta coupler), and R₃ represents an aryl group (including the group having a substituent).
The magenta coupler residual group represented by Cp preferably includes 5-pyrazolone magenta couplers and coupler residual groups derived from pyrazolotriazole type magenta couplers, and particularly preferably includes the one represented by Formula (IV) shown below:

Formula (IV):

In the formula, R₄ represents an aryl group; R₅ represents an acylamino group, an anilino group, a ureido group or a carbamoyl group and preferably represents an anilino group; and R₄ and R₅ may each be substituted.
The aryl group represented by R₄ is preferably a phenyl group. The substituent for the aryl group represented by R₄ may include, for example, a halogen atom (for example, fluorine, chlorine, bromine), an alkyl group (for example, methyl, ethyl), an alkoxy group (for example, methoxy, ethoxy), an aryloxy group (for example, phenyloxy, naphthyloxy), an acylamino group (for example, benzamide, a-(2,4-di-t-amyl- phenoxy)butylamide), a sulfonylamino group (for example, benzenesulfonamide, n-hexadecansulfonamide), a sulfamoyl group (for example, methylsulfamoyl, phenylsulfamoyl), a carbamoyl group (for example, an n-butylcarbamoyl group, a phenyl carbamoyl group). a sulfonyl group (for example, methylsulfonyl, n-dodecylsulfonyl, benzenesulfonyl), an acyloxy group, an ester group, a carboxyl group, a sulfo group, a cyano group, or a nitro group.
Specific examples of R₄ are phenyl, 2,4,6-trichlorophenyl, pentachlorophenyl, pentafluorophenyl, 2,4-6-trimethylphenyl, 2-chloro-4,6-dimethylphenyl, 2,6-dichloro-4-methylphenyl, 2,4-dichloro-6-methylphenyl, 2,4-dichloro-6-methoxylphenyl, 2,6-dichloro-4-methoxylphenyl, or 2,6-dichloro-4-[a-(2,4-di-t-amylphenoxy)-acetamide]phenyl.
The acylamino group represented by R₅ may include, for example, pivaloylamino, n-tetradecanamide, a-(3-pentadecylphenoxy)butylamide, 3-[a-(2,4-di-t-amylphenoxy)acetamido]benzamide, benzamide, 3-ac- etoamidobenzamide, 3-(3-n-dodecylsuccinimide)benzamide, or 3-(4-n-dodecyloxybenzenesulfonamide)-benzamide.
The anilino group represented by R₅ may include, for example, anilino, 2-chloroanilino, 2,4-dich- loroanilino, 2,4-dichloro-5-methoxyanilino, 4-cyanoanilino, 2-chloro-5-[a-(2,4-di-t-amylphenoxy)butylamido]-anilino,2-chloro-5-(3-octadecenylsuccinimide)anilino, 2-chloro-5-n-tetradecanamidoanilino, 2-chloro-5-[a-(3-t-butyl-4-hydroxyphenoxy)tetradecanamido]anilino, or 2-chloro-5-n-hexadecansulfoamidoanilino.
The ureido group represented by R₅ may include, for example, methylureido, phenylureido, or 3-[a-(2,4-di-t-amylphenoxy)butylamido]phenylureido.
The carbamoyl group represented by R₅ may include, for example, n-tetradecylcarbamoyl, phenylcarbamoyl, or 3-[a-(2,4-di-t-amylphenoxy)acetamide]phenylcarbamoyl.
The aryl group represented by R₃ is preferably a phenyl group or a naphthyl group.
The substituent for the aryl group represented by R₁ may include, for example, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, an acyloxy group, a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, a sulfonamide group, a carbamoyl group, or a sulfamoyl group.
Particularly preferably substituents include an alkyl group, a hydroxyl group, an alkoxy group and acylamino group.
Examples of the colored magenta couplers represented by Formula (III) are shown below, but by no means limited to these.
The colored magenta coupler according to this invention can be synthesized following methods disclosed in, for example, Japanese Unexamined Patent Publications No. 123625/1974, No. 131448/1974, No. 42121/1977, No. 102723/1977, No. 52532/1979, No. 1726/1983, U.S. Patents No. 2,763,552, No. 2,801,171, No. 3,519,429.
The pyrazolotriazole type magenta coupler and the colored magenta coupler of this invention can be used in any layer or layers of the above silver halide emulsion layers, but, in general, they are used in a green-sensitive silver halide emulsion layer. The green sensitive silver halide emulsion layer preferably comprises two or more emulsion layers When the green-sensitive silver halide emulsion layer comprises two or more emulsion layers, the couplers are required to be used in at least one of the emulsion layers, and preferably used in two or more of the emulsion layers. When the green-sensitive silver halide emulsion layer comprises two or more emulsion layers which are different in sensitivity, the couplers should preferably be used in at least the most sensitive layer.
The pyrazolotriazole type magenta coupler of this invention may be used usually in the range of 1 x 10-³ mole to 1 mole, preferably 1 x 10-² mole to 8 x 10-¹, per 1 mole of silver halide in the monodisperse light-sensitive silver halide emulsion layer. However, in the interest of the sharpness, it is preferably used in an amount of 50 mole % or more, more preferably from 60 to 80 mole %, based on the amount of all couplers in the layer in which the coupler is added.
Also, the colored magenta coupler of this invention is required to be used in an amount of 17 mole % or more, preferably not less than 20 mole % and less than 50 mole %, more preferably not less than 30 mole % and less than 50 mole %, based on the amount of all couplers in a layer in which the coupler is present.
The layer containing the magenta coupler and the colored magenta coupler of this invention may contain magenta couplers not of this invention. However, the magenta couplers not of this invention should generally be present in an amount of less than 20 mole % based on the amount of all couplers.
The magenta couplers that can be used together in the green-sensitive silver halide emulsion layer of this invention include pyrazolone compounds, indazolone compounds, cyanoacetyl compounds and pyrazoloazole compounds not of this invention. In particular, pyrazolone compounds can be used advantageously.
Specific examples of usable magenta couplers include those disclosed in Japanese Unexamined Patent Publications No. 111631/1974, No. 29236/1981, No. 94752/1982, Japanese Patent Publication No. 27930/1973, U.S. Patents No. 2,600,788, No. 3,062,653, No. 3,408,194, No. 3,519,429, and Research Disclosure No. 12443.
When adding the magenta coupler of this invention and the other couplers, they can be incorporated into the green-sensitive silver halide emulsion layer by an oil protection dispersion method or a latex dispersion method. If the couplers are alkali soluble, they may be added as an alkaline solution.
From the viewpoints of color reproducibility, sharpness and graininess, it is preferable to use a DIR compound as well.
Typical DIR compounds usable with this invention include DIR couplers wherein a group capable of forming a compound showing a development-restraining action when eliminated from an active site of a coupler, is introduced into the active site, which are disclosed, for example, in British Patent No. 935,454, U.S. Patents No. 3,227,554, No. 4,095,984, No. 4,149,886, Japanese Unexamined Patent Publication No. 151944/1982. The above DIR couplers have a property that, when coupled with an oxidized product in a color developing agent, a mother nucleus of the coupler forms a dye and releases a development restrainer. Also included are compounds that can release a development restrainer but form no dye when coupled with an oxidized product in a color developing agent, as disclosed in U.S. Patents No. 3,652,345, No. 3,928,041, No. 3,958,993, No. 3,961,959 and No. 4,052,213, Japanese Unexamined Patent Publications No. 110529/1978, No. 13333/1979, No. 161237/1980.
Also usable with this invention are timing DIR compounds which, when reacted with an oxidized product in a color developing agent, the mother nucleus forms a dye or a colorless compound and the eliminated timing group releases a development restrainer by an intramolecular nucleophilic substitution reaction or elimination reaction, as disclosed in Japanese Unexamined Patent Publications No. 145135/1979, No. 114946/1981 and No. 154234/1982.
Also usable with this invention are timing DIR compounds in which, when reacted with an oxidized product in a color developing agent, the timing group as mentioned above becomes bonded to the coupler mother nucleus capable of forming a perfectly diffusible dye.
Typical examples of the DIR compounds are shown below.

[Exemplary Compounds]

The DIR compounds that can be used in combination with this invention are preferably added to a light-sensitive silver halide emulsion layer.
Two or more kinds of the DIR compounds may be contained in the same layer, or, alternatively, DIR compounds of the same kind may be contained in different layers.
In general, these DIR compounds are used preferably in an amount of 2 x 10-⁴ to 1 x 10^-1, more preferably 1 x 10-³ to 2 x 10-², per mole of silver in the emulsion layer.
For the purpose of improving image quality, it is preferable to use timing DIR compounds, or diffusible DIR compounds wherein the released restraining group is migratory.
In a silver halide emulsion used in this invention, any silver halide may be used including silver bromide, silver iodobromide, silver iodochloride, silver chlorobromide, silver chloroiodobromide and silver chloride which are used in ordinary silver halide emulsions, but preferably silver bromide, silver iodobromide and silver chloroiodobromide.
Silver halide grains used in the silver halide emulsions may be obtained by an acidic method, a neutral method or an ammoniacal method. The grains may be allowed to grow at one time, or grow after seed grains have been formed. The method of preparing the seed grains and the method of growing them may be same or different.
The silver halide emulsion may be obtained by simultaneously mixing halide ions and silver ions, or by preparing an aqueous solution in which either one of them is present and then mixing into it the other of them. Alternatively, taking into account the critical growth rate of silver halide crystals, it may be formed by successively simultaneously adding halide ions and silver ions while controlling pH and pAg in the mixing vessel. By such procedures, there can be obtained silver halide grains having regular crystal form and substantially uniform grain size. Halogen formulation in a grain may be varied by employing a conversion method in an arbitrary step during formation of AgX.
During the growth of silver halide grains, silver halide solvents such as ammonia, thioether and thiourea can be used.
In the course of formation and/or growth of the silver halide grains, metal ions may be added to the grains by use of at least one cadmium salt, zinc salt, lead salt, thallium salt, iridium salt (including a complex salt), rhodium salt (including a complex salt), or iron salt (including a complex salt) in order to incorporate any of these metal elements on the inside of the grains and/or the surface of the grains, and also reduction sensitizing nuclei may be introduced on the inside of the grains and/or the surface of the grains by placing the grains in a suitable reductive atmosphere.
The silver halide emulsion may be either one from which unnecessary soluble salts have been removed after completion of the growth of silver halide grains, or one from which they have not been removed. When the salts are removed, they can be removed according to the method disclosed in Research Disclosure (hereinafter simply "RD") No. 17643, Paragraph II.
The silver halide grains may be any of those having uniform distribution of silver halide formulation in a grain, or core/shell grains having different silver halide formulation between the inside portion and the surface layer of a grain.
The silver halide grains may be grains such that a latent image is formed chiefly on the surface, or grains such that a latent image is formed chiefly in the inside of a grain.
The silver halide grains may have any regular crystal form such as a cube, an octahedron and a tetradecahedron, or those having an irregular crystal form such as a sphere and a plate. In these grains, there may also be used those having any ratio of the {100} face to the {111} face. Also, they may have a composite form of these crystal forms, or comprise a mix of grains having various crystal forms.
As for the size of the silver halide grains, those having grain size of 0.05 to 30 µ, preferably 0.1 to 20 µ, may be used.
The silver halide emulsion has a narrow grain size distribution (hereafter called a "monodispersed emulsion"). The monodispersed emulsion herein mentioned refers to an emulsion having a value of 0.20 or less when the standard deviation of grain size distribution is divided by the average grain size (the grain size refers to the diameter of a grain in the case of a spherical silver halide, and, in the case of a grain having a shape other than the spherical shape, it refers to the diameter calculated by converting a projected image of the grain into a round image having the same area) and it may be used alone or as a mixture of several kinds. Also, the polydispersed emulsion and the monodispersed emulsion may by used by mixing them.
The silver halide emulsion may be used by mixing two or more kinds of silver halide emulsions which have been separately formed.
The silver halide emulsion can be chemically sensitized according to conventional methods. Namely, a sulfur sensitization method, a selenium sensitization method, a reduction sensitization method and a noble metal sensitization method using noble metal compounds such as gold and so forth can be used alone or in combination.
The silver halide emulsion can be optically sensitized to a desired wavelength region by using a dye known as a sensitizing dye in the field of photography. The sensitizing dye may be used alone, or may be used in combination with two or more of the dyes. Together with the sensitizing dye, a dye having itself no spectral sensitization effect, or a supersensitizing agent which is a compound substantially absorbing no visible light and capable of strengthening the sensitizing action of the sensitizing dye, may be contained in the emulsion.
As the sensitizing dye, there may be used cyanine dyes, merocyanine dyes, composite cyanine dyes, composite merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, sterile dyes and hemioxanol dyes.
Particularly useful dyes are cyanine dyes, merocyanine dyes and composite merocyanine dyes.
To the silver halide emulsion, a compound known as an antifoggant or a stabilizer in the field of photography may be added during chemical ripening, after completion of chemical ripening and/or before coating of a silver halide emulsion after completion of chemical ripening, for the purpose of preventing a light-sensitive material from becoming fogged during manufacturing steps, during preservation or during photographic processing, or for the purpose of keeping the photographic performance stable.
As a binder (or protective colloid) for the silver halide emulsion, it is advantageous to use gelatin, but it is also possible to use hydrophilic colloids such as gelatin derivatives, a graft polymer of gelatin with other macromolecules, other proteins, sugar derivatives, cellulose derivatives and synthetic hydrophilic high molecular substances such as homopolymers or copolymers.
Photographic emulsion layers and other hydrophilic colloid layers of the light-sensitive material in which the silver halide emulsion of this invention is used can be hardened by using one or more kinds of hardening agents that can crosslink binder (or protective colloid) molecules to enhance the film strength. The hardening agents can be added in such an amount that a light-sensitive material can be hardened to the extent that no hardening agent is required to be added in the processing solution. It, however, is also possible to add the hardening agent in the processing solution.
For example, there can be used, alone or in combination, aldehydes (such as formaldehyde, glyoxal and glutaraldehyde), N-methylol compounds (such as dimethylol urea and methyloldimethylhydantoin), dioxane derivatives (such as 2,3-dihydroxydioxane), active vinyl compounds (such as 1,3,5-triacryloyl- hexahydro-s-triazine and 1,3-vinylsulfonyl-2-propanol), active halogen compounds (such as 2,4-dichloro-6-hydroxy-s-triazine), mucohalogeno-acids (such as mucochloric acid and mucophenoxychloric acid).
A plasticizer can be added to the silver halide emulsion layers and/or other hydrophilic colloid layers of the light-sensitive material for the purpose of enhancing flexibility. Preferable plasticizers include the compounds disclosed in RD No. 17643, Paragraph XII-A.
For the purpose of improving dimensional stability a dispersion (latex) of a water insoluble or hardly soluble synthetic polymer can be contained in the photographic emulsion layers and other hydrophilic colloid layers.
For example, there can be used, alone or in combination, alkyl acrylate or methacrylate, alkoxyalkyl acrylate or methacrylate, glycidyl acrylate or methacrylate, acrylamide or methacrylamide, vinyl esters (such as vinyl acetate), acrylonitrile, olefin, or styrene; or polymers containing monomer components comprising a combination of these with acrylic acid, methacrylic acid, o:,,8-unsaturated dicarboxylic acid, hydroxyalkyl acrylate or methacrylate, sulfoalkyl acrylate or methacrylate, styrene sulfonic acid.
In color development processing, a dye-forming coupler capable of forming a dye through a coupling reaction with an oxidized product of an aromatic primary amine developing agent (for example, p-phenylenediamine derivative, aminophenol derivative) is used in the emulsion layers of the light-sensitive material. In the usual case, the dye forming coupler is selected in a manner such that there is formed a dye capable of absorbing spectral light in a light-sensitive emulsion layer, and thus a yellow dye-forming coupler is used in a blue-sensitive emulsion layer; a magenta dye-forming coupler, in a green-sensitive emulsion layer; and a cyan dye-forming coupler, in a red-sensitive emulsion layer. However, the light-sensitive silver halide color photographic material may also be prepared by using the couplers in a manner different from the above combination, depending on the purpose.
These dye-forming couplers may preferably have a group having 8 or more of carbon atoms, which is called a ballast group and makes the couplers non-diffusible. These dye-forming couplers may be either four equivalent ones wherein silver ions of 4 molecules must be reduced in order for a dye of 1 molecule to be formed, or two equivalent ones wherein silver ions of 2 molecules may only be reduced. The dye-forming couplers may contain a compound that can release a photographically useful substance such as a development accelerator, a bleach accelerator, a developer, a silver halide solvent, a toning agent, a hardening agent, a fogging agent, an antifoggant, a chemical sensitizer, a spectral sensitizer or a desensitizer, through coupling with an oxidized product of a developing agent.
A colorless coupler (also called a competing coupler) which performs a coupling reaction with an oxidized product of an aromatic primary amine developing agent, but does not form any dye, can be also used in combination with the dye-forming couplers.
As the yellow dye-forming coupler, known acylacetoanilido type couplers can be preferably used. Among them, benzoyl acetoanilide type compounds and pivaloyl acetoanilide type compounds are preferable. Specific examples of usable yellow couplers include those disclosed, for example, in U.S. Patents No. 2,875,057, No. 3,265,506, No. 3,408,194, No. 3,551,155, No. 3,582,322, No. 3,725,072 and No. 3,891,445; German Patent No. 1,547,868, German Patent Application Publications No. 2,219,917, No. 2,261,361 and No. 2,414,006, British Patent No. 1,425,020; Japanese Patent Publication No. 10783/1976; Japanese Unexamined Patent Publications No. 26133/1972, No. 73147/1973, No. 6341/1975, No. 87650/1975, No. 123342/1975, No. 130442/1975, No. 21827/1976, No. 102636/1976, No. 82424/1977, No. 115219/1977 and No. 95346/1983.
As the cyan dye-forming couplers, phenol type couplers and naphthol type couplers are generally used. Specific examples of usable cyan couplers include those disclosed, for example, in U.S. Patents No. 2,423,730, No. 2,474,293, No. 2,801,171, No. 2,895,826, No. 3,476,563, No. 3,737,326, No. 3,758,308 and No. 3,893,044, Japanese Unexamined Patent Publications No. 37425/1972, No. 10135/1975, No. 25228/1975, No. 112038/1975, No. 117422/1975, No. 130441/1975, or couplers disclosed in Japanese Unexamined Patent Publication No. 98731/1983.
Among the dye-forming couplers, colored couplers, DIR couplers, DIR compounds, image stabilizers, color fog preventive agents, ultraviolet absorbents, brightening agents which are not required to be absorbed on the surface of silver halide crystals, hydrophobic compounds can be dispersed by use of various methods including a solid dispersion method, a latex dispersion method, an oil-in-water emulsification dispersion method which can be appropriately selected depending on the chemical structure of the hydrophobic compounds, such as couplers. As the oil-in-water emulsification dispersion method, conventionally known methods for dispersing hydrophobic additives such as couplers can be applied. Usually, the method may be carried out by dissolving the couplers in a high boiling organic solvent having a boiling point of 150°C or more, optionally together with a low boiling and/or water soluble organic solvent. Then carrying out the emulsification dispersion in a hydrophilic binder such as an aqueous gelatin solution by use of a surface active agent and a dispersing means such as a stirrer, a homogenizer, a colloid mill, a flow jet mixer, or an ultrasonic device; followed by adding the dispersion to a hydrophilic colloid layer solution. There may be inserted a step of removing the dispersing solution or, at the same time of the dispersion, the low boiling organic solvent as well.
The high boiling solvent to be used may include organic solvents having a boiling point of 150°C or more such as phenol derivatives, alkyl phthalates, phosphates, citrates, benzoates, alkyl amides, aliphatic acid esters and trimesic acid esters which do not react with an oxidized product of a developing agent.
Together with the high boiling solvent, or in place thereof, a low boiling or water soluble organic solvent can be used. The organic solvent which has a low boiling point and is substantially soluble in water may include ethyl acetate, propyl acetate, butyl acetate, butanol, chloroform, carbon tetrachloride, nitromethane, nitroethane, benzene.
When the dye-forming couplers, colored couplers, DIR couplers, DIR compounds, image stabilizers, color fog preventive agents, ultraviolet absorbents, brightening agents have an acid radical substituent such as carboxylic acid and sulfonic acid, they can be introduced in a hydrophilic colloid as an alkaline aqueous solution.
As a dispersion auxiliary used when hydrophobic compounds are dissolved in a solvent comprising a low boiling solvent alone or in combination with a high boiling solvent and dispersed in water using a mechanical means or ultrasonic wave, there can be used anionic surface active agents, nonionic surface active agents, cationic surface active agent and amphoteric surface active agents.
A color fog preventive agent can be used in order to prevent color turbidity from being caused by the migration of an oxidized product or an electron migrator of a developing agent between emulsion layers (between the same color sensitive layers and/or different color sensitive layers) of the light-sensitive material, or to prevent the deterioration of sharpness or formation of overly conspicuous graininess.
The color fog preventive agent may be contained in the emulsion layers per se, or may be contained in an intermediate layer provided between emulsion layers.
An image stabilizing agent for preventing the deterioration of dye images can be used in the light-sensitive material. Preferably usable compounds include the compounds disclosed in RD No. 17643, Paragraph VII-J.
Hydrophilic colloid layers such as protective layers and intermediate layers of a light-sensitive material may contain an ultraviolet absorbent in order to prevent fog due to static discharge caused by charging of the light-sensitive material by friction, and to prevent deterioration of images due to ultraviolet rays.
A formalin scavenger can be used in the light-sensitive material in order to prevent deterioration of the magenta dye-forming couplers due to the presence of formalin during the preservation of light-sensitive materials.
When a dyestuff, an ultraviolet absorbent and so forth are contained in the hydrophilic colloid layers of the light-sensitive material, they may be mordanted by using a mordant such as a cationic polymer.
Compounds such as development accelerators and development restrainers that may change the developing properties, or bleach accelerators can be added to the silver halide emulsion layers and/or other hydrophilic colloid layers of the light-sensitive material. The compounds preferably usable as development accelerators include the compounds disclosed in RD No. 17643, Paragraphs XXI-B to -D, and preferable development restrainers include the compounds disclosed in RD No. 17643, Paragraph XXI-E. For the purposes of development acceleration a black and white development accelerator and/or a precursor thereof may also be used.
For the purposes of increasing sensitivity, increasing contrast, and accelerating development, the emulsion layers of the light-sensitive photographic material may contain polyalkylene oxides or derivatives thereof such as ethers, esters or amines; thioether compounds; thiomorpholines; quaternary ammonium compounds; urethane derivatives; urea derivatives; imidazole derivatives.
In the light-sensitive material, a brightening agent can be used for the purpose of increasing the whiteness of the white ground and also making less conspicuous the coloring of the white ground portion. Compounds preferably usable as the brightening agent are disclosed in RD No. 17643, Paragraph V.
The light-sensitive material can be provided with auxiliary layers such as a filter layer, an anti-halation layer and an anti-irradiation layer. These layers and/or the emulsion layers may contain a dye that may be flowed out of the light-sensitive material, or bleached, during the development processing. Such a dye may include oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes, cyanine dyes, azo dyes.
To the silver halide emulsion layers and/or other hydrophilic colloid layers of the light-sensitive material, a matte agent can be added for the purpose of decreasing the gloss of the light-sensitive material, improving the writing performance, and preventing mutual sticking of light-sensitive materials. Any such agents can be used, for example, silicon dioxide, titanium dioxide, magnesium dioxide, aluminum dioxide, barium sulfate, calcium carbonate, polymers of acrylic acid and methacrylic acid and esters thereof, polyvinyl resins, polymers of polycarbonates and styrene and copolymers thereof. The matte agent may preferably have a grain size of 0.05 11. to 10 µ. It is added preferably in an amount of 1 to 300 mg/m^2.
A lubricant can be added to the light-sensitive material in order to decrease sliding friction.
An antistatic agent aiming at preventing static charge can be added to the light-sensitive material. The antistatic agent may be used in an antistatic layer provided on the side of the support where no emulsion layer is laminated, or may be used in an emulsion layer and/or a protective colloid layer other than the emulsion layers provided on the side of a support on which emulsion layers are laminated. Antistatic agents preferably used are the compounds disclosed in RD No. 17643, Paragraph XIII.
In the photographic emulsion layers and/or other hydrophilic colloid layers, a variety of surface active agents can be used for the purpose of improving coating performance, preventing static charge, improving slidability, emulsification dispersion, preventing adhesion, or improving photographic performances (such as development acceleration, hardening and sensitization).
The support used in the light-sensitive material of this invention may include flexible reflective supports made of paper or synthetic paper laminated with a-olefin polymers (for example, polyethylene, polypropylene, an ethylene/butene copolymer); films comprising semisynthetic or synthetic high molecular compounds such as cellulose acetate, cellulose nitrate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate and polyamide; flexible supports comprising these films provided with a reflection layer; glass; metals; ceramics.
The light-sensitive material may be applied directly on the surface of the support having been subjected to corona discharging, ultraviolet irradiation, flame treatment, or through interposition of at least one subbing layer for improving adhesion, antistatic performance, dimensional stability, abrasion resistance, hardness, anti-halation performance, friction characteristics and/or other characteristics of the surface of the support.
In the coating of the light-sensitive material, a thickening agent may be used in order to improve the coating performance. Also, in the case of, for example, a hardening agent, which has a fast reactivity and therefore may cause gelation before coating if previously added in a coating solution, it is preferably mixed just before the coating by a static mixer.
Particularly useful coating method may include extrusion coating and curtain coating by which two or more layers can be simultaneously coated, but packet coating is also useful for certain purposes. Coating rate can be arbitrarily selected.
There is no particular limitation on the possible surface active agents, but there may be added, for example, natural surface active agents such as saponin; nonionic surface active agents such as alkylene oxides, glycerols and glycidols; cationic surface active agents such as higher alkyl amines, quaternary ammonium salts, pyridines and other hetero cyclic rings, and phosphoniums or sulfoniums; anionic surface active agents containing an acidic group such as carboxylic acid, sulfonic acid, phosphoric acid, sulfate and phosphate; and amphoteric surface active agents such as amino acids, aminosulfonic acids, and sulfate or phosphate of amino alcohols. For the same purpose, it is also possible to use fluorine type surface active agents.
To obtain color images by using the light-sensitive material of this invention, color photographic processing is carried out after exposure. The color processing is carried out according to steps comprising a color developing step, a bleaching step, a fixing step, a water washing step, and optionally a stabilizing step. The processing step using a bleaching solution and the processing step using a fixing solution can be replaced by a bleach-fixing step using a combined bleaching and fixing solution. It is also possible to carry out a monobath processing which employs a combined developing and bleaching and fixing solution that can carry out color developing, bleaching and fixing in one bath.
In combination with these processing steps, the processing may further comprise a pre-hardening step, a neutralizing step, a stop fixing step and a post-hardening step. In these processings, a color developing agent or a precursor thereof may be contained in advance in the materials in order to perform, in place of the color developing step, activator processing which carries out developing in an activator solution. Also, the activator processing can be applied in the monobath process.
The color developing solution generally comprises an alkaline aqueous solution containing a color developing agent. The color developing agent is an aromatic primary amine color developing agent, including aminophenol type and p-phenylenediamine type derivatives. These color developing agents can be used in the form of salts of organic acids and inorganic acids, and there can be used, for example, hydrochloride, sulfate, p-toluenesulfonate, sulfite, oxalate, benzenesulfonate.
These compounds may be used generally in a concentration of about 0.1 to 30 g per 1 liter of a color developing solution, preferably in concentration of about 1 to 15 g per 1 liter. An amount less than 0.1 g may result in insufficient color development density.
The above color developing agent may be used alone or in combination with one or more kinds of them. Further, the above color developing agent may be incorporated into the color photographic material per se. In such a case, the light-sensitive silver halide color photographic material can also be processed by using an alkaline solution (an activator) in place of the color developing solution, and can be bleach-fixed immediately after the processing by the alkaline solution.
Specific examples of this invention will be described below, but working embodiments of this invention are by no means limited to these.
In all of Examples shown below, the addition amount to the light-sensitive silver halide photographic material refers to an amount per 1 m² unless particularly mentioned. Also, the amounts of silver halide and colloidal silver are shown by calculating them in terms of silver.

Examples

On a support made of triacetyl cellulose film, the respective layers as shown below were formed successively from the side of the support to produce a multi-layer color photographic element, Sample-1.

Sample 1 (Comparative Example):

First layer: Antihalation layer (HC-1)

A gelatin layer containing black colloidal silver.

Second layer: Intermediate layer (I.L.)

A gelatin layer containing an emulsified dispersion of 2,5-di-t-octylhydroquinone.

Third layer: Low sensitivity red-sensitive silver halide emulsion layer (RL-1)

Comprising AgBrl containing 8 mole % of Agl; an average grain size (r) of 0.30 I1.m.
Monodispersed emulsion (Emulsion I) ... Coated silver weight: 1.5 g/m².
Sensitizing dye I ... 6 x 10-⁵ mole per 1 mole of silver.
Sensitizing dye II ...1.0 x 10-⁵ mole per 1 mole of silver.
Cyan coupler (C-1) ... 0.06 mole per 1 mole of silver.
Colored cyan coupler (CC-1) ... 0.003 mole per 1 mole of silver.
DIR compound (D-12) ... 0.0015 mole per 1 mole of silver.
DIR compound (D-15) ... 0.004 mole per 1 mole of silver.

Fourth layer: High sensitivity red-sensitive silver halide emulsion layer (RH-1)

Comprising AgBrl containing 7.0 mole % of Agl; an average grain size (r) of 0.65 µm.
Monodispersed emulsion (Emulsion II) ... Coated silver weight: 1.3 g/m².
Sensitizing dye I ... 3 x 10-⁵ mole per 1 mole of silver.
Sensitizing dye II ...1.0 x 10-⁵ mole per 1 mole of silver.
Cyan coupler (C-1) ... 0.02 mole per 1 mole of silver.
Colored cyan coupler (CC-1) ... 0.0015 mole per 1 mole of silver.
DIR compound (D-15) ... 0.001 mole per 1 mole of silver.

Fifth layer: Intermediate layer (I.L.)

A gelatin layer, same as the second layer.

Sixth layer: Low sensitivity green-sensitive silver halide emulsion layer (GL-1)

Emulsion I ... Coated silver weight: 1.3 g/m².
Sensitizing dye III ... 2.5 x 10-⁵ mole per 1 mole of silver.
Sensitizing dye IV ...1.2 x 10-⁵ mole per 1 mole of silver.
Magenta coupler (M-1) ... 0.9 mole per 1 mole of silver.
Colored magenta coupler (CM-1) ... 0.017 mole per 1 mole of silver.
DIR compound (D-12) ... 0.0010 mole per 1 mole of silver.
DIR compound (D-17) ... 0.0030 mole per 1 mole of silver.

Seventh layer: High sensitivity green-sensitive silver halide emulsion layer (GH-1)

Emulsion II ... Coated silver weight: 1.1 g/m².
Sensitizing dye III ... 1.5 x 10-⁵ mole per 1 mole of silver.
Sensitizing dye IV ...1.0 x 10-⁵ mole per 1 mole of silver.
Magenta coupler (M-1) ... 0.020 mole per 1 mole of silver.
Colored magenta coupler (CM-1) ... 0.004 mole per 1 mole of silver.
DIR compound (D-12) ... 0.0010 mole per 1 mole of silver.

Eighth layer: Yellow filter layer (YC-1)

A gelatin layer containing an emulsified dispersion comprising yellow colloidal silver and 2,5-di-t-octylhydroquinone.

Ninth layer: Low sensitivity blue-sensitive silver halide emulsion layer (BL-1)

Comprising AgBrl containing 6 mole % of Agl; an average grain size of 0.38 um.
Monodispersed emulsion (Emulsion III) ... Coated silver weight: 0.9 g/m².
Sensitizing dye V ... 1.3 x 10-⁵ mole per 1 mole of silver.
Yellow coupler (Y-1) ... 0.29 mole per 1 mole of silver.
DIR compound (D-3) ... 0.01 mole per 1 mole of silver.

Tenth layer: High sensitivity blue-sensitive emulsion layer(BH-1)

Comprising AgBrl containing 10 mole % of Agl; an average grain size (r) of 0.8 µm.
Monodispersed emulsion (Emulsion IV) ... Coated silver weight: 0.5 g/m².
Sensitizing dye V ... 1.0 x 10-⁵ mole per 1 mole of silver.
Yellow coupler (Y-1) ... 0.08 mole per 1 mole of silver.
DIR compound (D-3) ... 0.002 mole per 1 mole of silver.

Eleventh layer: First protective layer (Pro-1)

A gelatin layer comprising silver iodobromide (Agl: 1 mole %; average grain size: 0.07 µm), having a coated silver weight of 0.5 g/m², and containing ultraviolet absorbents UV-1 and UV-2.

Twelfth layer: Second protective layer (Pro-2)

A gelatin layer containing polymethyl methacrylate particles (diameter: 1.5 µm) and formalin scavenger (HS-1 ).
To each of the layers, a gelatin hardener (H-1) and a surface active agent were added in addition to the above compositions.
The compounds contained in the respective layers of Sample 1 are as follows:

Sensitizing dye I:
- Anhydro
- 5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfopropyl)-thiacarbocyanine hydroxide
Sensitizing dye II:
- Anhydro
- 9-ethyl-3,3'-di-(3-sulfopropyl)-4,5,4',5'-dibenzothiacarbocyaninehydroxide
Sensitizing dye III:
- Anhydro
- 5,5'-diphenyl-9-ethyl-3,3'-di-(3-sulfopropyl)-oxacarbocyanine hydroxide
Sensitizing dye IV:
- Anhydro 9-ethyl-3,3'-di-(3-sulfopropyl)-5,6,5',6'-dibenzooxacarbocyanine hydroxide
Sensitizing dye V:
- Anhydro
- 3,3'-di-(3-sulfopropyl)-4,5-benzo-5'-methoxythiacyanine

Subsequently, Samples 2 to 12 wherein the magenta coupler and the colored magenta coupler were varied as shown in Table 1 were produced.
Samples 1 to 12 thus produced were exposed, and thereafter subjected to the following development processing.

Processing steps (38 ° C):

The processing solution used in each of the processing steps had the following formulation.
Results obtained are shown in Table 1.
In Table 1, the amount of couplers added is indicated in terms of mole % per 1 mole of silver halide; the numerals in parentheses in the column of the amount indicate proportional percentage (%) to all the couplers in the corresponding layer; MTF indicates a relative value when Sample 1 was assumed to be 100; RMS is indicated by a 1,000 time value of the standard deviation in the density value fluctuation caused when a density point of the minimum density + 0.7 was scanned by use of a microdensitometer having an open scanning area of 250 µm^2. Accordingly, the values indicate that, the larger the MTF is and the smaller the RMS is, the higher image quality has been achieved.
As will be apparent from Table 1, both the sharpness and the graininess are remarkably improved in the samples in which the magenta coupler comprises pyrazolotriazole type magenta coupler and the colored magenta coupler is contained in the proportion of 17 % or more of the amount of all couplers in the layer containing the same.
Particularly, they are further improved when applied in high sensitivity layers.

Claims

1. A light-sensitive silver halide color photographic material having at least one monodisperse light-sensitive silver halide emulsion layer containing a pyrazolotriazole type magenta coupler and a colored magenta coupler, wherein the layer containing the pyrazolotriazole type magenta coupler and the colored magenta coupler comprises 17 mole % or more of said colored magenta coupler based on the amount of all couplers in said layer.

2. A light-sensitive silver halide color photographic material according to Claim 1, wherein said pyrazolotriazole type magenta coupler is of Formula (I) or (II) shown below:

wherein R₁ and R₂ each represent an optionally substituted alkyl group, an aryl group or a hetero ring and R₁ and R₂ maybe linked through -O-, -N- or -S-; and Z represents hydrogen or a group which may be eliminated when a dye is formed in a coupling reaction with an oxidized product of an aromatic primary amine color developing agent.

3. A light-sensitive silver halide color photographic material according to Claim 2, wherein said alkyl group represented by R₁ or R₂ is a straight chain or branched alkyl group having 1 to 20 carbon atoms; said aryl group represented by R₁ or R₂ is a phenyl group or a naphtyl group; and said hetero ring represented by R₁ or R₂ is a 5- or 6-membered ring containing at least one nitrogen, oxygen or sulfur atom.

4. A light-sensitive silver halide color photographic material according to Claim 2 or 3, wherein said alkyl group, aryl group or hetero ring represented by R₁ or R₂ is linked through a linking group selected from acylamino, carbamoyl, sulfonamide, sulfamoylcarbonyl, carbonyloxy, oxycarbonyl, ureido, thioureido, thioamide, sulfone or sulfonyloxy.

5. A light-sensitive silver halide color photographic material according to Claim 2, 3 or 4 wherein Z independently represents halogen, alkoxy, aryloxy, acyloxy, arylthio, alkylthio, and a group of formula

(wherein Z₂ represents a group of atoms which completes a 5- or 6-membered ring containing at least one carbon, oxygen, nitrogen or sulfur together with the nitrogen).

6. A light-sensitive silver halide color photographic material according to claim 2 or 3, wherein said pyrazolotriazole type magenta coupler represents any one of the following compounds:

or

7. A light-sensitive silver halide color photographic material according to any one of the preceding Claims, wherein said colored magenta coupler is of formula [III]:

wherein Cp represents a magenta coupler residual group, provided that the azo group is attached to an active site of the magenta coupler, and R₃ represents an aryl group.

8. A light-sensitive silver halide color photographic material according to Claim 7, wherein said magenta coupler residual group represented by Cp represents a coupler residual group derived from a pyrazolotriazole type magenta coupler or a 5-pyrazolone magenta coupler.

9. A light-sensitive silver halide color photographic material according to Claim 8, wherein said magenta coupler residual group is represented by Formula (IV) shown below:

wherein R₄ represents an optionally substituted aryl group; R₅ represents an optionally substituted acylamino, anilino, ureido or carbamoyl group.

10. A light-sensitive silver halide color photographic material according to Claim 9, wherein R₅ represents an anilino group.

11. A light-sensitive silver halide color photographic material according to Claim 9, wherein said aryl group represented by R₄ is a phenyl group and has at least one substituent selected from halogen, alkyl, alkoxy, aryloxy, acylamino, sulfonylamino, sulfamoyl, carbamoyl, sulfonyl, acyloxy, ester, carboxyl, sulfo cyano or nitro.

12. A light-sensitive silver halide color photographic material according to any one of the preceding Claims, wherein said pyrazolotriazole type magenta coupler and said colored magenta coupler are contained in a green-sensitive silver halide emulsion layer.

13. A light-sensitive silver halide color photographic material according to Claim 12, wherein said green-sensitive silver halide emulsion layer comprises two or more emulsion layers.

14. A light-sensitive silver halide color photographic material according to Claim 13, wherein said two or more green-sensititive silver halide emulsion layers are different in sensitivity and the most sensitive layer of the green-sensitive silver halide emulsion layers contains the pyrazolotriazole type magenta coupler and the colored magenta coupler.

15. A light-sensitive silver halide color photographic material according to any one of the preceding Claims, wherein said pyrazolotriazole type magenta coupler is present in an amount of from 1 x 10-³ to 1 mole per 1 mole of the silver halide in the monodisperse light-sensitive silver halide emulsion layer.

16. The light-sensitive silver halide color photographic material according to Claim 1, wherein said pyrazolotriazole type magenta coupler is present in an amount of 50 mole % or more based on the amount of all couplers in the layer in which the coupler is present.

17. The light-sensitive silver halide color photographic material according to Claim 1, wherein said colored magenta coupler is present in an amount of not less than 20 mole % and less than 50 mole % based on the amount of all couplers in the layer in which the coupler is present.

18. The light-sensitive silver halide color photographic material according to Claim 17, wherein said colored magenta coupler is present in an amount of not less than 30 mole % and less than 50 mole % based on the amount of all couplers in the layer in which the coupler is present.

19. The light-sensitive silver halide color photographic material according to Claim 1, wherein said monodispersed light-sensitive silver halide emulsion layer further contains a DIR compound.