EP0234742A2

EP0234742A2 - Silver halide color photographic material

Info

Publication number: EP0234742A2
Application number: EP19870300687
Authority: EP
Inventors: Masanobu Konishiroku Photo Int. Co. Ltd. Miyoshi; Kaoru Konishiroku Photo Int. Co. Ltd. Onodera
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 1986-01-27
Filing date: 1987-01-27
Publication date: 1987-09-02
Anticipated expiration: 2007-01-27
Also published as: EP0234742A3; JPH07117728B2; EP0234742B1; JPS62173464A; DE3751177D1

Abstract

A silver halide color photographic material having a halide emulsion layer on a support is disclosed. One silver halide emulsion layer contains a yellow-dye forming coupler of the general formula (I) shown below, one silver halide emulsion layer contains a magenta-dye forming coupler of the general formula (II) shown below, and one silver halide emulsion layer contains a cyan-dye forming coupler of the general formula (III) shown below, and the silver halide color photographic material affords a magenta y to cyan y ratio of 0.85-1.00, and a yellow γ to cyan y ratio of 0.83 - 1.00 when said photographic material is subjected to monochromatic exposure to blue, green and red light under the conditions specified below, then developed and processed under the conditions specified below, and subsequently subjected to measurement of cyan γ, magenta y and yellow γ values of the respective colors by the method specified below:

(where R, is an alkyl or aryl group; R₂ is an aryl group; and Z, is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent)

(where Z signifies the group of non-metallic atoms that are necessary to form a nitrogen-containing heterocyclic ring which may optionally have a substituent; X is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent; and R is a hydrogen atom or a substituent);

(where R₂₁ is an alkyl or aryl group; R₂₂ is an alkyl, cycloalkyl, aryl or heterocyclic group; R₂₃ is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, provided that R₂₃ may combine with R₂₁ to form a ring; and Z₂ is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent);

Conditions of monochromatic exposure
- (1) exposure to red light light source : tungsten lamp exposure time : 0.5 seconds filter : Kodak WRATTEN gelatin filter No. 29
- (2) exposure to green light light source : tungsten lamp exposure time : 0.5 seconds filter : Kodak WRANTTEN gelatin filter No. 61
- (3) exposure to blue light light source : tungsten lamp exposure time : 0.5 seconds filter : Kodak WRATTEN gelatin filter No. 478

provided that exposure through a neutral step tablet is performed in each of (1). (2) and (3) in order to achieve variation in the amount of exposure;

Conditions of development and subsequent prccessing

(1) scheme (steps and the duration of their times)
(2) Composition of processing flulds (color developing solution)
Method of y measurement

The reflection density of the image formed on a developed and subsequently processed sample is measured with a densitometer that satisfies the geometric conditions for reflection density measurement specified in JIS 7612 - 1982 and which has interference filters that feature maximum transmission wavelengths of 644 nm, 546 nm and 436 nm for the measurement of cyan, magenta and yellow reflection densities, respectively, and each of which has a half-width of no greater than 18 nm; the γ value for each color is calculated by the following formula:

where E₁ and E₂ represent the amounts of exposure that are necessary to provide reflection densities of Dmin + 0.5 and Dmin + 1.8, respectively, Dmin signifying the reflection density of unexposed areas.

Cyan y, magenta y and yellow γ are defined as follows:

cyan y: calculated from the reflection density measured with an interference filter of 644 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a cyan coupler of the general formula (III);
magenta γ: calculated from the reflection density measured with an interference filter of 546 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a magenta coupler of the general formula (II);
yellow γ: calculated from the reflection density measured with an interference filter of 436 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a yellow coupler of the general formula (I).

Description

FIELD OF THE INVENTION

The present invention relates to a silver halide color photographic material and, more particularly, to a silver halide color photographic material that is capable of superior color reproduction.

BACKGROUND OF THE INVENTION

Color reproduction in color photography employing silver halide color photographic materials is commonly achieved by the subtractive processes. Common silver halide color photographic materials use yellow-dye forming couplers (hereinafter referred to simply as yellow couplers) in blue-sensitive emulsion layers, magenta-dye forming couplers (hereinafter referred to simply as magenta couplers) in green-sensitive emulsion layers, and cyan-dye forming couplers (hereinafter referred to simply as cyan couplers) in red-sensitive emulsion layers. In color development following imagewise exposure, these dye-forming couplers enter into coupling reaction with the oxidized product of a color developing agent that has formed by development of the light-sensitive silver halides. Color reproduction is accomplished by the formation of yellow, magenta and cyan dye images as a result of this coupling reaction of the respective dye-forming couplers.
Success of color reproduction is one of the most important factors that determine the quality of color pictures. Therefore, ever since the discovery of the principles of color photography described in the preceding paragraph, many efforts have been made in order to achieve improved color reproduction.
While color reproduction depends on a number of factors, the most important one is the spectral absorption characteristics of color-forming dyes. In principle, the spectral absorption characteristics of color-forming dyes can be adjusted to some extent by changing the chemical structures of the dyes. However, the absorption characteristics that can be used in practical applications are considerably limited since they must be adapted to the color development process employed. While numerous compounds have been reviewed by many researchers, those which exhibit completely satisfactory spectral absorption characteristics are yet to be attained.
Color-forming dyes may be considered to be preferable in terms of color reproduction if they have the following spectral absorption characteristics: the wavelength that produces a maximum spectral absorption in the visible range (said absorption is hereinafter referred to as the primary absorption) is appropriate; the shape of the primary absorption peak is appropriate; and the amount of unwanted absorptions that occur in addition to the primary absorption (such absorptions are hereinafter referred to as the secondary absorption). It is known that substantial improvement can be attained for the primary absorption by proper selection of coupler substituents or high-boiling point organic solvents for couplers and this requirement has been met almost completely in the state of the art. On the other hand, any secondary absorption by magenta and cyan dyes in the blue region will cause serious adverse effects on color reproduction and is commonly dealt with in the art by such methods as masking with colored couplers and the use of the inter- image effect. However, these methods are not always available; for instance, masking with colored couplers is available for production of intermediate images as in color negative films but not available for production of final images as in color reversal films and color papers. It is therefore desired to develop couplers that provide color-forming dyes that experience a minimum degree of the secondary absorption.
Various compounds have been proposed for use as magenta couplers that experience reduced secondary absorptions and they include: pyrazolinobenzimidazoles of the types described in German Patent Nos. 1,070,030 and 1,127,220; azoles of the types described in French Patent No. 2,075,583, U.S. Patent Nos. 3,705,896 and 3,725,067, British Patent No. 1,252,418, and Japanese Patent Application (OPI) Nos.
99437/1984, 125732/1984, 228252/1984, 162548/1984, 171956/1984, 33552/1985, 43659/1985, 35732/1985, 55343/1985, 57838/1985 and 168143/1985 (the term OPI as used herein means an unexamined published Japanese patent application); and indazolones of the type described in U.S. Patent No. 2,673,801.
However, practically none of these compounds have been commercialized because most of them have such disadvantages as insufficient color formation, the production of unwanted coloring materials during development, and the formation of color-forming dyes that are labile to light or heat.
Among these compounds,azoles exhibit fairly satisfactory performance and are known to provide couplers that are very desirable for achieving good color reproduction as manifested by reduced secondary absorption and a sharp primary absorption peak.
Phenolic and naphtholic compounds are generally used as cyan couplers and 2,5-diacylaminophenolic couplers are known to provide color-forming dyes that have desirable spectral absorption characteristics for color reproduction; for this particular type of cyan couplers, see U.S. Patent No. 2,895,826, and Japanese Patent Application (OPI) Nos. 112038/1975, 109630/1978, 163537/1980, 31953/1984, 100440/1984, 121332/1984, 124341/1984, 139352/1984, 146050/1984, 166956/1984.
One would therefore readily conclude that if the above- mentioned azolic magenta couplers and/or 2,5-diacylaminophenolic cyan couplers were used in light-sensitive materials such as color reversal films and color papers which are intended to produce final images, color photographic images having superior color reproduction could be attained. In fact, however, satisfactory color photographic images (e.g., color prints) could not always be produced by simply using those azolic magenta couplers and/or 2,5-diacylaminophenolic cyan couplers, either independently or in combination. For instance, when a color paper containing these magenta couplers and cyan couplers was processed and evaluated for areas of color reproduction, with the lightness held constant, by the method described in Japanese Patent Application (OPI) No. 100440/1984, apparently enlarged areas of color reproduction were attained. In prints from a negative that was used to take the actual scene, the color of the human skin and other specific colors could be reproduced very faithfully but, on the other hand, a detectable color balance shift occurred in the highlights and shadows or the reproduction of certain colors was far from being satisfactory. Therefore, generally speaking, the overall quality of the color pictures produced by incorporating the aforementioned azolic magenta couplers and 2,5-diacylaminophenolic cyan couplers was not as good as expected initially.
Some researchers prepared samples of color photographic material which they claimed would attain desired color reproduction even if used in practical applications. However, in almost all cases, these samples were found to provide satisfactory color reproduction only under certain limited conditions (with regard, for example, to development, exposure or viewing) and none of them were capable of exhibiting consistently high quality under the versatile conditions which will encounter the handling of commercial products.
The present inventors conducted extensive studies in order to solve the aforementioned problems of the prior art. As a result, the inventors have found that particularly good color reproduction can be achieved if both the azolic magenta coupler and 2,5-diacylaminophenolic cyan coupler specified above are used and if the ratios of y-values attained by allowing three silver halide emulsion layers, which respectively contain a yellow dye-forming coupler, said magenta coupler and said cyan coupler, to form monochromatic colors independently are controlled to be at specific values. The present invention has been accomplished on the basis of this finding.

SUMMARY OF THE INVENTION

One object, therefore, of the present invention is to provide a color photographic image that faithfully reproduces the colors of all scenes to be encountered in practical applications.
Another object of the present invention is to provide a silver halide color photographic material that ensures the faithful reproduction of the colors of all scenes to be encountered in practical applications.
These objects of the present invention can be attained by a silver halide color photographic material that has on a support a silver halide emulsion layer containing a yellow-dye forming coupler of the general formula (I) shown below, a silver halide emulsion layer containing a magenta-dye forming coupler of the general formula (II) shown below, and a silver halide emulsion layer containing a cyan-dye forming coupler of the general formula (III) shown below, and which affords a magenta y to cyan y ratio of 0.85 - 1.00, and a yellow y to cyan y ratio of 0.83 - 1.00 when said photographic material is subjected to monochromatic exposure to blue, green and red light under the conditions specified below, then developed and processed under the conditions specified below, and subsequently subjected to measurement of cyan y, magenta y and yellow y values of the respective colors by the method specified below:
(where R₁ is an alkyl or aryl group; R₂ is an aryl group; and Z₁ is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent);
(where Z signifies the group of non-metallic atoms that are necessary to form a nitrogen-containing heterocyclic ring which may optionally have a substituent; X is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent; and R is a hydrogen atom or a substituent);
(where R₂₁ is an alkyl or aryl group; R₂₂ is an alkyl, cycloalkyl, aryl or heterocyclic group; R₂₃ is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, provided that R₂₃ may combine with R₂₁ to form a ring; and Z₂, is a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent);

Conditions of monochromatic exposure

(1) exposure to red light
(2) exposure to green light
(3) exposure to blue light
provided that exposure through a neutral step tablet is performed in each of (1), (2) and (3) in order to achieve variation in the amount of exposure;

Conditions of development and subsequent processing

(1) scheme (steps and the duration of their times)
(2) Composition of processing fluids (color developing solution)
(bleach-fixing solution)

Method of y measurement

The reflection density of the image formed on a developed and subsequently processed sample is measured with a densitometer that satisfies the geometric conditions for reflection density measurement specified in JIS 7612 - 1982 and which hqs interference filters that feature maximum transmission wavelengths of 644 nm, 546 nm and 436 nm for the measurement of cyan, magenta and yellow reflection densities, respectively, and each of which has a half-width of no greater than 18 nm; the y value for each color is calculated by the following formula:
where E₁ and E₂ represent the amounts of exposure that are necessary to provide reflection densities of Dmin + 0.5 and Dmin + 1.8, respectively, Dmin signifying the reflection density of unexposed areas.
Cyan y, magenta y and yellow y are defined as follows:

cyan y : calculated from the reflection density measured with an interference filter of 644 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a cyan coupler of the general formula (III);
magenta y: calculated from the reflection density measured with an interference filter of 546 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a magenta coupler of the general formula (II);
yellow y : calculated from the reflection density measured with an interference filter of 436 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a yellow coupler of the general formula (I).

Specific Construction of the Invention

The color photographic material of the present invention uses a yellow-dye forming coupler having the general formula (I) shown below, a magenta-dye forming coupler having the general formula (II) shown below, and a cyan-dye forming coupler having the general formula (III) shown below.
In formula (I), R_l is a straight-chained or branched alkyl group (e.g., butyl) or an aryl group (e.g., phenyl), with an alkyl group (e.g., t-butyl) being preferred; R₂is an aryl group (preferably phenyl); the alkyl or aryl group represented by R₁ and R₂ may have a substituent, and an aryl group as R₂ is preferably substituted by, for example, a halogen atom or an alkyl group.
The yellow coupler of formula (I) is preferably represented by the following general formula (IA):
where R₁ and R₂ are each the same as defined for R_I and R₂ in formula (I); and Z₁' is a group that can be eliminated upon reaction with the oxidized product of a color developing agent.
The group that is represented by Z₁' in formula (IA) and which can be eliminated upon reaction with the oxidized product of a color developing agent is preferably represented by the following general formula (I-1) or (I-2). Among the groups of formula (I-1), one that is represented by the following general formula (I-1') is particularly preferable:
(where Z₁" signifies a group of non-metallic atoms that are capable of forming a 4- to 7-membered ring);
(where R₃ is an aryl, heterocyclic or acyl group, with an aryl group being preferred); and
(where Z₁"' signifies a group of non-metallic atoms that are capable of forming a 4- to 6-membered ring together with
Yellow couplers of formula (I) that are particularly preferable for the purposes of the present invention are represented by the following general formula (I'):
where R₄ and R₈ each represents a hydrogen atom, a halogen atom or an alkoxy group, R₄ and R₈ being preferably a halogen atom and a hydrogen atom, respectively; R₅; R₆ and R₇ independently are a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a carboxyl group, an alkoxycarbonyl group, a carbamyl group, a sulfon group, a sulfamyl group, an alkylsulfonamido group, an acylamido group, a ureido group, or an amino group, each of R₅ and R₆ being preferably a hydrogen atom and R₇ being preferably an alkoxycarbonyl, acylamido or alkylsulfonamido group; and Z₁ is the same group as defined for Z₁ in formula (I) and is preferably one that is represented by formula (I-1) or (1-2), with one represented by formula (I-I') being particularly preferable.
Illustrative, but by no means limiting, examples of the yellow couplers that may be used in the present invention are listed below.
(The remaining space is left blank.)
The yellow couplers of formula (I) may be used either independently or in admixture. They may also be used in combination with other yellow couplers.
The yellow couplers are preferably added in amounts of 0.05 - 2 moles per mole of silver halide, with the range of 0.1 - 1 mole being more preferable. In terms of the amount present in one silver halide emulsion layer, the range of 1 x 10^-5 to 5 x 10^-2 moles per square meter is preferable and the range of 5 x 10 5 to 1 x 10^-2 mole per square meter is more preferable.
where Z represents a group of the non-metallic atoms necessary for forming a nitrogen-containing heterocyclic ring, provided that the ring formed by Z may have a substituent; X represents a hydrogen atom or a substituent capable of being eliminated upon reaction with the oxidation product of a color developing agent; and R is a hydrogen atom or a substituent.
In the magenta coupler of formula (II), the substituent represented by R includes, for example, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkinyl group, an aryl group, a heterocyclic group, an acyl group, a sulfonyl group, a sulfinyl group, a phosphonyl group, a carbamoyl group, a sulfamoyl group, a cyano group, a spire-compound residue, a bridged hydrocarbon compound residue, an alkoxy group, an aryloxy group, a heterocyclicoxy group, a siloxy group, an acyloxy group, a carbamoyloxy group, an amino group, an acylamino group, a sulfonamide group, an imido group, a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylthio group, an arylthio group and a heterycyclicthio group.
The halogen atom includes, for example, chlorine and bromine atoms, the chlorine atom being particularly preferable.
The alkyl group represented by R is preferably one having 1 to 32 carbon atoms, the alkenyl group and the alkinyl group are preferably those having 2 to 32 carbon atoms, and the cycloalkyl group and the cycloalkenyl group are preferably those having 3 to 12, particularly 5 to 7, carbon atoms, the alkyl, alkenyl and alkinyl groups each including those having a straight or branched chain.
These alkyl, alkenyl, alkinyl, cycloalkyl and cycloalkenyl groups each may have one or more substituents. Such substituents include, in addition to an aryl group, a cyano group, a halogen atom, a heterocyclic group, a cycloalkyl group, a cycloalkenyl group, a spiro-compound residue and a bridged hydrocarbon compound residue, for example, those substituted through the carbonyl group, such as acyl, carboxy, carbamoyl, alkoxycarbonyl and aryloxycarbonyl groups, and those substituted through the hetero atom, for example, those substituted through the oxygen atom, such as hydroxy, alkoxy, aryloxy, heterocyclicoxy, siloxy, acyloxy and carbamoyloxy groups, those substituted through the nitrogen atom, such as nitro, amino (including dialkylamino and the like), sulfamonylamino, alkoxycarbonylamino, aryloxycarbonylamino, acylamino, sulfoneamido, imido and ureido groups, those substituted through the sulfur atom, such as alkylthio, arylthio, heterocyclicthio, sulfonyl, sulfinyl and sulfamoyl groups, and those substituted through the phosphorus atom, such as a phosphonyl group and the like.
Examples of the alkyl group represented by R include, for example, methyl, ethyl, isopropyl, t-butyl, pentadecyl, heptadecyl, 1-hexylnonyl, 1,1'-dipentylnonyl, . 2-chloro-t-butyl, trifluoromethyl, 1-ethoxytridecyl, 1-methoxyisopropyl, methanesulfonylethyl, 2,4_-di-t-amylphenoxymethyl, anilino, 1-phenylisopropyl, 3_-m-butanesulfonaminophenoxypropyl, 3-4'-{α-[4"(p-hydroxy- benzenesulfonyl)phenoxy]dodecanoylamino} phenylpropyl, 3-{4'-[α-(2",4"-di-t-amylphenoxy)butaneamido]phenyl}- propyl, 4-[a-(O-chlorophenoxy)tetradecanamidophenoxy]-propyl, allyl, cyclopentyl and cyclohexyl groups.
The aryl group represented by R is preferably a phenyl gruop, and may have a substituent such as an alkyl, alkoxy or acylamino group.
Examples of the aryl group include phenyl, 4-t-butylphenyl, 2,4-di-t-amylphenyl, 4-tetradecaneamido- phenyl, hexadecyl-oxyphenyl and 4'-[α-(4"-t-butylphenoxy)-tetoradecaneamido]phenyl groups.
The heterocyclic group represented by R is preferably a 5- to 7-membered heterocyclic ring, and may be substituted or may be condensed. Examples of the heterocyclic group include 2-furyl, 2-thienyl, 2-pyrimidinyl and 2-benzothiazolyl groups.
The acyl group represented by R includes, for example, an alkylcarbonyl group such as acetyl, phenylacetyl, dodecanoyl and a-2,4-di-t-amylfenoxybutanoyl groups, and an arylcarbonyl group such as benzoyl, 3-pentadecycloxy- benzoyl and p-chlorobenzoyl groups.
The sulfonyl group represented by R includes, for example, an alkylsulfonyl group such as methylsulfonyl and dodecylsulfonyl groups, and an arylsulfonyl group such as benzenesulfonyl and p-toluenesulfonyl groups.
The sulfinyl group represented by R includes, for example, an alkylsulfinyl group such as ethylsulfinyl; octylsulfinyl and 3-fenoxybutylsulfinyl groups and an arylsulfinyl group such as phenylsulfinyl and m-penta- decylphenylsulfinyl groups.
The phosphonyl group represented by R includes, for example, an alkylphosphonyl group such as butylotyl phosphonyl group, an alkoxyphosphonyl group such as octyloxyphosphonyl group, an aryloxyphosphonyl group such as phenoxyphosphonyl group and an arylphosphonyl croup such as phenylphosphonyl group.
The carbamoyl group represented by R includes, for example, those substituted with an alkyl or aryl (preferably phenyl) group, such as, N-methylcarbamoyl, N,N-dibutylcarbamoyl, N-(2-pentadecyloctylethyl)carbamoyl, N-ethyl-N-dodecylcarbamoyl and N-{3-(2,4-di-t-amylphenoxy)-propyl}carbamoyl group.
The sulfamoyl group represented by R includes, for example, those substituted with an alkyl or aryl (preferably phenyl) group, such as N-propylsulfamoyl, N,N-diethylsulfamoyl, N-(2-pentadecyloxyethyl)sulfamoyl, N-ethyl-N-dodecylsulfamoyl and N-phenylsulfamoyl groups.
The spiro-compound residue represented by R includes, for example, spiro[3,3]heptan-1-yl and the like.
The bridged hydrocarbon compound residue represented by R includes, for example, bicyclo(2,2,1]heptane-1-yl, tricyclo[3,3,1,1^3,7]decane-1-yl and 7,7-dimethyl-bicyclo-[2,2,1]heptane-1-yl.
The alkoxy group reprented by R includes, for example, those substituted further with such a substituent(s) as is shown above with the alkyl group, such as methoxy, propoxy, 2-ethoxyethoxy, pentadecyloxy, 2-dodecyloxy- ethoxy and phenethyloxyethoxy.
The aryloxy group represented by R is preferably a phenyloxy group, and includes, for example, those of which aryl nucleus is further subsituted with such a substituent(s) or an atom(s) as is shown above with the aryl group, such as phenoxy, p-t-butylphenoxy and m-pentadecylphenoxy groups.
The heterocyclicoxy group represented by R is preferably one having a 5- to 7-membered heterocyclic ring, and includes those of which heterocyclic ring has a substituent, such as 3,4,5,6-tetrahydropyranyl-2-oxy and 1-phenyltetrazole-5-oxy groups.
The siloxy group represented by R includes those substituted with an alkyl group, for example, trimethyl- siloxy, triethylsiloxy and dimethylbutylsiloxy groups.
The acyloxy group represented by R includes, for example, alkylcarbonyloxy and arylcarbonyloxy groups, and further includes those having a substituent(s) such as acetyloxy, a-chloroacetyloxy and benzoyloxy groups.
The carbamoyloxy group represented by R includes those substituted with an alkyl or aryl group, such as N-ethylcarbamoyloxy, N,N-diethylcarbamoyloxy and N-phenylcarbamoyloxy groups.
The amino group represented by R includes those substituted with an alkyl or aryl (preferably phenyl) group, such as ethylamino, anilino, m-chloroanilino, 3-pentadecyloxycarbonylanilino and 2-chloro-5-hexa- decaneamidoanilino groups.
The acylmaino group represented by R includes alkylcarbonylamino and arylcarbonylamino (preferably phenylcarbonylamino) groups, and further includes those having a substituent(s) such as acetamido, a-ethylpropane- amido, N-pnenylacetamido, dodecaneamido, 2,4-di-t-amyl- phenoxyacetamido and a-3-t-butyl-4-hydroxyphenoxybutane- amido groups.
The sulfonamido group represented by R includes alkylsulfonylamino and arylsulfonylamino groups, and further includes those having a substituent(s), such as methylsulfonylamino, pentadecylsulfonylamino, benzen- sulfonamido, p-toluenesulfonamido and 2-methoxy-5-t-amylbenzenesulfonamido groups.
The imido group represented by _R includes those which are open-chained or close-chained, and further includes those having a substituent(s), such as, succinimido, 3-heptadecylsuccinimido, phthalimido and glutarimido groups.
The ureido group represented by R includes those substituted with an alkyl or aryl (preferably phenyl) group, such as N-ethylureido, N-methyl-N-decylureido, N-phenylureido and N-p-tolylureido groups.
The sulfamoylamino group represented by R includes those substituted with an alkyl or aryl (preferably phenyl) group, such as N,N-dibutylsulfamoylamino, N-methylsulfamoylamino and N-phenylsulfamoylamino groups.
The alkoxycarbonylamino group represented by R includes those having a substituent(s), such as methoxy- carbonylamino, methoxyethoxycarbonylamino and octadecyloxy- carbonylamino groups.
The aryloxycarbonylamino group represented by R includes those having a substituent(s), such as phenoxy- carbonylamino and 4-methylphenoxycarbonylamino groups.
The alkoxycarbonyl group represented by R includes those having a substituentts),such as methoxycarbonyl, butyloxycarbonyl, dodecyloxycarbonyl, octadecyloxy- carbonyl, ethoxymethoxycarbonyloxy and benzyloxycarbonyl groups.
The aryloxycarbonyl group represented by R includes those having a substituent(s), such as phenoxycarbonyl, p-chlorophenoxycarbonyl and m-pentadecyloxyphenoxycarbonyl groups.
The alkylthio group represented by R includes those having a substituent (s), such as ethylthio, dodecylthio, octadodecylthio, phenethylthio and 3-phenoxypropylthio groups.
The arylthio group represented by R is preferably a phenylthio group, and includes those having a substituent(s), such as phenylthio, p-methoxyphenylthio, 2-t-octylphenylthio, 3-octadecylphenylthio, 2-carboxyphenylthio and p-acetaminophenylthio groups.
The heterocyclicthio group represented by R is preferably a 5- to 7-membered heterocyclicthio group, and includes those having a condensed ring or having a substituent(s). Examples of such heterocyclicthio group include 2-pyridylthio, 2-benzothiazolylthio and 2,4-diphenoxy-1,3,5-triazol-6-thio groups.
The substituent represented by X that is capable of leaving upon reaction with the oxidized product of a color developing agent includes, for example, those substituted through the carbon, oxygen, sulfur or nitrogen atom other than the halogen atom (chlorine, bromine or fluorine atom).
The groups which are substituted through the carbon atom include, in addition to the carboxyl group, a group represented by the following formula:
(wherein R₁ ¹ is the same in meaning as said R; Z' is the same in meaning as said Z; and R₂' and R₃' each represents a hydrogen atom, an aryl, alkyl or heterocyclic group), a hydroxymethyl group and a triphenylmethyl group.
The groups which are substituted through the oxygen atom include, for example, alkoxy, aryloxy, heterocyclicoxy, acyloxy, sulfonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, alkyloxalyloxy and alkoxyoxalyloxy groups.
The alkoxy group includes those having a substituent(s), such as ethoxy, 2-phenoxyethoxy, 2-cyanoethoxy, phenethyloxy, and p-chlorobenzyloxy groups.
The aryloxy group is preferably a phenoxy group, and includes those having a substituent(s). Examples of such aryloxy group include phenoxy, 3-methylphenoxy, 3-dodecylphenoxy, 4-methanesulfoneamidophenoxy, 4-[a-(3^1-pentadecylphenoxy)butaneamido]phenoxy, hexadecyl- carbamoylmethoxy, 4-cyanophenoxy, 4-methanesulfonyl- phenoxy, I-naphthyloxy and p-methoxyphenoxy groups.
The heterocyclicoxy group is preferably a 5- to 7-membered heterocyclicoxy group, and may be a condensed ring or include those having a substituent(s). Examples of such heterocyclicoxy group include I-phenyltetra- zolyloxy and 2-benzothiazolyloxy groups.
The acyloxy group includes, for example, an alkylcarbonyloxy group such as acetoxy and butanoyloxy groups, an alkenylcarbonyloxy group such as a cinnamoyloxy group, and an arylcarbonyloxy group such as a benzoyloxy group.
The sulfonyloxy group includes, for example, butane- sulfonyloxy and methanesulfonyloxy groups.
The alkoxycarbonyloxy group includes, for example, ethoxycarbonyloxy and benzyloxycarbonyloxy groups.
The aryloxycarbonyloxy group includes a phenoxy- carbonyloxy group and the like.
The alkyloxalyloxy group includes, for example, a methyloxalyloxy group.
The alkoxyoxalyloxy group includes an ethoxyoxalyl- oxy group and the like.
The group which is substituted through the sulfur atom includes, for example, alkylthio, arythio, heterocyclicthio and alkyloxythiocarbonylthio groups.
The alkylthio group includes butylthio, 2-cyano- ethylthio, phenetylthio and benzylthio groups.
The arylthio group includes phenylthio, 4-methane- sulfoneamidophenylthio, 4-dodecylphenetylthio, 4- nonafluoropentaneamidophenetylthio, 4-carboxyphenylthio and 2-ethoxy-5-t-butylphenylthio groups.
The heterocyclicthio group includes, for example, 1-phenyl-1,2,3,4-tetrazolyl-5-thio and 2-benzothiazolylthio groups.
The alkyloxythiocarbonylthio group includes a dodecyloxythiocarbonylthio group and the like.
The group which is substituted through the nitrogen atom includes, for example, one represented by the formula
wherein R₄' and R₅' each represents a hydrogen atom, an alkyl, aryl, heterocyclic, sulfamoyl, carbamoyl, acyl, sulfonyl, aryloxycarbonyl or alkoxycarbonyl group, and R₄' and R₅' may cooperate to form a heterocyclic ring, provided that R₄' and R₅' are not hydrogen atoms at the same time.
The alkyl group may be straight-chained or branched and is preferably one having 1 to 22 carbon atoms. Also, the alkyl group may include those having a substituent(s). Examples of such substituent include, for example, aryl, alkoxy, aryloxy, alkylthio, arylthio, alkylamino , arylamino, acylamino, sulfoneamido, imino, acyl, alkylsulfonyl, arylsulfonyl, carbamoyl, sulfamoyl, alkoxycarbonyl, aryloxycarbonyl, alkyloxycarbonylamino, aryloxycarbonylamino, hydroxy, carboxyl and ciano groups and halogen atom. Examples of such alkyl group includes, for example, ethyl, octyl, 2-ethylhexyl and 2-chloroethyl group.
The aryl group represented by R₄' or R₅' is preferably one having 6 to 32 carbon atoms, particularly a phenyl or naphtyl group, and may include those having a substituent(s). Such substituent includes a substituent for the alkyl group represented by R₄' or R₅' and an alkyl group. Examples of the aryl group include, for example, phenyl, 1-naphtyl and 4-methylsulfonyl- phenyl groups.
The heterocyclic group represented by R₄' or R₅' is preferably a 5- or 6-membered ring, and may be a condensed ring or include those having a substituent(s). Examples of such heterocyclic group include 2-furyl, 2-quinolyl, 2-pyrimidyl, 2-:benzothiazolyl and 2-pyridyl groups.
The sulfamoyl group represented by R₄' or R₅' includes N-alkylsulfamoyl, N,N-dialkylsulfamoyl, N-arylsulfamoyl and N,N-diarylsulfamoyl groups, and these alkyl and aryl groups may have such a substituent(s) as is mentioned with respect to the alkyl and aryl groups. Examples of such sulfamoyl group includes, for example, N,N-diethylsulfamoyl, N-methylsulfamoyl, N-dodecylsulfamoyl and N-p-tolylsulfamoyl groups.
The carbamoyl group represented by R₄' or R₅' includes N-alkylcarbamoyl, N,N-dialkylcarbamoyl, N-arylcarbamoyl and N,N-diarylcarbamoyl groups, and these alkyl and aryl groups may have such a substituent(s) as is mentioned with respect to the alkyl and aryl groups. Examples of such carbamoyl group include, for example, N,N-diethylcarbamoyl, N-methylcarbamoyl, N-dodecylcarbamoyl, N-p-cianophenylcarbamoyl and N-p-tolylcarbamoyl groups.
The acyl group represented by R₄' or R₅' includes, for example, alkylcarbonyl, arylcarbonyl and hetero- cycliccarbonyl groups, and the alkyl, aryl and heterocyclic groups may have a substituent(s). Examples of such acyl group include, for example, hexafluorobutanoyl, 2,3,4,5,6-pentafluorobenzoyl, acetyl, benzoyl, naphtoyl and 2-furylcarbonyl groups.
The sulfonyl group represented by R₄' or R_S' includes alkylsulfonyl, arylsulfonyl and heterocyclic- sulfonyl groups, and may have a substituent(s). Examples of such sulfonyl group include, for example, ethanesulfonyl, benzenesulfonyl, octanesulfonyl, naphthalenesulfonyl and p-chlorobenzenesulfonyl groups.
The aryloxycarbonyl group represented by R₄' or R₅' may have such a substituent(s) as is mentioned with respect to the aryl group, and includes a phenoxycarbonyl group and the like.
The alkoxycarbonyl group represented by R₄' or R₅' may have such a substituent(s) as is mentioned with respect to alkyl group, and includes methoxycarbonyl, dodecyloxycarbonyl and benzyloxycarbonyl groups.
The heterocyclic ring which is formed through cooperation of R₄' and R₅ ¹ is preferably a 5- or 6- membered ring, may be saturated or unsaturated, may or may not be an aromatic ring, or may be a condensed ring. Examples of such heterocyclic ring include, for example, N-phthalimido, N-succinimide, 4-N-urazolyl, 1-N-hydantoinyl, 3-N-2,4-dioxooxazolidinyl, 2-_N-1,1-dioxo-3-(2H)-oxo-1,2- benzthiazolyl, 1-pyrrolyl, 1-pyrrolidinyl, 1-pyrazolyl, 1-pyrazolidinyl, 1-piperidinyl, 1-pyrrolinyl, 1-imidazolyl, 1-imidazolinyl, 1-indolyl, 1-isoindolinyl, 2-iso-indolyl, 2-isoindolinyl, 1-benzotriazolyl, 1-benzoimidazolyl, 1-(1,2,4-triazolyl), 1-(1,2,3-triazolyl), 1-(1,2,3,4-tetrazolyl), N-morpholinyl, 1,2,3,4-tetrahydroquinolyl, 2-oxo-1-pyrrolidinyl, 2-1H-pyridone, phthalazione and 2-oxo-1-piperidinyl groups. These heterocyclic groups may be substituted by alkyl, aryl, alkyloxy, aryloxy, acyl, sulfonyl, alkylamino, arylamino, acylamino, sulfoneamino, carbamoyl, sulfamoyl, alkylthio, arylthio, ureido, alkoxycarbonyl, aryloxycarbonyl, imido, nitro, cyano, carboxyl groups as well as by a halogen atom and the like.
The nitrogen-containing heterocyclic ring which is formed by Z or Z' includes pyrazol, imidazol, triazol and tetrazol rings, and may have such a substituent(s) as is mentioned with respect to R.
When the substituent(s) (for example either of R and R to R₈) on the heterocyclic ring in formula (_II) and in formulas (_II-1) to (II-7) to be mentioned later has the formula
(wherein R", X and Z" are the same in meaning as R, X and Z in formula (II), respectively), the coupler formed is the so-called bis-type coupler, which is included in the present invention. The ring which is firmed by Z, _Z', Z" as well as by Z₁ to be stated later may be condensed with another ring (for example, 5- to 7-membered cycloalkene). For example, in formula (II-4), R₅ and R₆, and in formula (II-5), R₇ and R₈, may cooperate to form a ring (for example, 5- to 7-membered cycloalkene, or benzene), respectively.
The coupler represented by formula (II) is preferably one represented by the following formula (IIA):
wherein R and Z are the same in meaning as R and Z in formula (II), respectively; and X' is a group capable of leaving upon reaction with the oxidized product of a color developing agent.
The coupler represented by formula (II) preferably includes, for example, those represented by the following formulas (II-1) to (II-6):

wherein R₁ to R₈ and X are the same in meaning as R and X mentioned above, respectively.
The coupler of formula (II) is preferably one represented by the following formula (II-7):
wherein R₁, X and Z₁ are the same in meaning as R, X and Z in formula (II), respectively.
Of the magenta couplers represented by formulas (II-1) to (11-6), those represented by formula (II-1) are particularly preferably.
With respect to the substituent(s) on the heterocyclic ring in formulas (II), (IIA) and (II-1) to (II-7), R in fomula (II), (IIA) and R₁ in formulas (II-1) to (II-7) are preferable when they satisfy the following requirement 1, the same R and R₁ are more preferable when they satisfy the following requirements 1 and 2, and the same R and R₁ are most preferable when they satisfy all of the following requirements 1, 2 and 3:

Requirement 1: The root atom bonded directly to the heterocyclic ring is a carbon atom.
Requirement 2: Said carbon atom has only one hydrogen atom or has no hydrogen atom at all, bonded thereto.
Requirement 3: The bonds between said carbon atom and adjacent atoms are all single bonds.

The most preferable substituents R and R₁ on the heterocyclic ring are those represented by the following formula (II-8)
wherein R₉, R₁₀ and R₁₁ each represents a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkinyl group, an aryl group,a heterocyclic group, an acyl. group, a sulfonyl group, a sulfinyl group, a phosphonyl group, carbamoyl group, a sulfamoyl gruop, a cyano group, a spiro-compound residue, a bridged hydrocarbon compound residue, an alkoxy group, an aryloxy group, a heterocyclicoxy group, a siloxy group, an acyloxy group, a carbamoyloxy group, an amino group, an acylamino group, a sulfonamide group, an imido group, a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylthio group, an arylthio group or a heterocyclicthio group, provided that at least two of R₉, R₁₀ and R₁₁ are not hydrogen atoms.
Two of R₉, R₁₀ and R₁₁, for example, R₉ and R₁₀ may cooperate to form a saturated or unsaturated ring (e.g. cycloalkane, cycloalkene or heterocyclic ring), and further R₁₁ may cooperate with said ring to form a bridged hydrocarbon compound residue.
The group represented by Rg to R₁₁ may have a substituent(s). Examples of said group and said substituent(s) are the same as the examples of the group represented by R in formula (II) and the substituent(s) mentioned with respect thereto.
Examples of the ring formed by the cooperation of, for example, R₉and R₁₀, as well as of the bridged hydrocarbon compound residue which is formed by R₉ to R₁₁ and the substituent(s) which said residue may have, are the same as the examples of the cycloalkyl, cycloalkenyl and heterocyclic groups represented by R in formula (II), and the substituent(s) mentioned with respect thereto.
The preferable substituents in formula (II-8) are as follows:

(i) Two of R₉ to R₁₁ are alkyl groups.
(ii) One of R₉ to R₁₁, for example, R₁₁ is a hydrogen atom, and the other two, R₉ and R₁₀, cooperate with the root carbon atom to form a cycloalkyl group.

Further, the preferable substituent.(s) in (i) above is such that two of R₉ to R₁₁ are alkyl groups, and the other one is a hydrogen atom or an alkyl group.
The alkyl and cycloalkyl groups each may have a substituent(s). Examples of such alkyl and cycloalkyl groups as well as of their substituents are the same as the examples of the alkyl and cycloalkyl groups represented by R in formula (_II) and the substituents mentioned with respect thereto.
A substituent(s) which the ring formed by Z in formula (II) and the ring formed by Z₁ in formula (II-7) each may have and a substituent(s) represented by each of R₂ to R₈ in formulas (II-1) to (II-5) are preferably those represented by the following formula (II-9):
wherein R¹ represents an alkylene group; and R² represents an alkyl group, a cycloalkyl group or an aryl group.
The alkylene group represented by R has 2 or more, preferably 3 to 6, carbon atoms in the straight chain, and includes those having a substituent.
Example of the substituent include those shown as the substituents which the alkyl group may have when R in formula (II) is an alkyl group.
The substituent is preferably a phenyl group.
Preferred examples of the alkylene group represented by R are listed below:
The alkyl group represented by R² may be one having a straight-chain or a branched-chain. Examples of such alkyl group include methyl, ethyl, propyl, iso-propyl, butyl, 2-ethylhexyl, octyl, dodecyl, tetradecyl, hexadecyl, octadecyl and 2-hexyldecyl groups.
The cycloalkyl group represented by R² is preferably one having a 5- or 6-membered ring, for example, a cyclohexyl group. 2
The alkyl and cycloalkyl groups represented by R include those having a substituent, for example, those exemplified as substituents for R 1.
Examples of the aryl group represented by R² include phenyl and napthyl groups, and also include those having a substituent. Examples of such substituent include, for example, alkyl groups having a straight chain or a branched chain and those exemplified as substituents for R¹. When two or more substituents are present, they may be the same or different.
More preferred couplers represented by formula (II) of the present invention are those represented by the following formula (II-10):
wherein R ¹ and R² are the same in meaning as R and R² in formula (II-9), and R and X are the same in meaning as R and X in formula (II), respectively.
Typical, but by no means limiting, examples of the coupler that can be used in the present invention are listed below.
These couplers were synthesized by reference to Journal of the Chemical Society, Perkin I (1977), pages 2047 to 2052, U.S. Patent No. 3,725,067 and Unexamined Published Japanese Patent Application Nos. 99437/1984, 42045/1983, 162548/1984, 171956/1984, 33552/1985, 43659/ 1985, 172982/1985 and 190779/1985.
The coupler of the present invention is usually incorporated in an amount within the range of 1 x 10^-3 mole to 1 mole, preferably 1 x 10^-2 mole to 8 x 10^-1 mole, per mole of silver halide, and preferably, an amount within the range of 1 x 10^-5 mole/m ² to 5 x 10^-2 mole/m2 more preferably 5 x 10^-5 mole/m ²to ₁ x 10^-2 mole/m², per one silver halide emulsion layer.
The coupler of the present invention may be used in alone or in combination and may be used in combination with any other type of magenta coupler.
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A cyan coupler represented by the general formula (III) is used in the present invention:
In formula (III), R₂₁ is an alkyl or aryl group; the alkyl group may be straight-chained or branched and is illustrated by methyl, ethyl, iso-propyl, butyl, pentyl, . octyl, nonyl or tridecyl, and the aryl group is exemplified by phenyl or naphthyl. The alkyl or aryl group represented by R₂₁ may have one or more substituents and typical substituents that can be introduced in a phenyl group include the following: a halogen atom, an alkyl group, a hydroxyl group, a cyano group, a nitro group, an alkoxy group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an aminosulfonamido group, an acylamino group, a carbamoyl group, a sulfonyl group, a sulfinyl group, a sulfoxy group, a sulfo group, an aryloxy group, an alkoxy group, a carboxyl group, an alkylcarbonyl group and an arylcarbonyl group. Two or more of these substituents may be introduced in a phenyl group. In formula (III), R21 may combine with R₂₃ to form a ring.
The alkyl, aryl, heterocyclic or cycloalkyl group signified by R₂₂ in formula (III) may have one or more substituents. Typical substituents that can be introduced in a phenyl group include: a halogen atom, an alkyl group, a hydroxyl group, a cyano group, a nitro group, an alkoxy group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an aminosulfonamido group, an acylamino group, a carbamoyl group, a sulfonyl group, a sulfinyl group, a sulfoxy group, a sulfo group, an aryloxy group, an alkoxy group, a carboxyl group, an alkylcarbonyl group and an arylcarbonyl group. Two or more of these substituents may be introduced in a phenyl group. Preferable examples of the group signified by R₂₂ are a polyfluoroalkyl group, an unsubstituted phenyl group and a phenyl group that has one or more substituents selected from a halogen atom, an alkyl group, an alkoxy group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkylsulfonyl group, all arylsulfonyl group, an alkylcarbonyl group, an arylcarbonyl group and a cyano group.
In formula (III), Z₂ signifies a hydrogen atom or a group that can be eliminated upon reaction with the oxidized product of a color developing agent.
Preferable examples of the cyan coupler of formula (III) are represented by the following general formula (IIIA):
where R₂₁, R₂₂ and R₂₃ are each the same as defined for R₂₁, R₂₂ and R₂₃ in formula (III), and Z₂' signifies a group that can be eliminated upon reaction with the oxidized product of a color developing agent.
Particularly preferable examples of the cyan coupler of formula (III) are represented by the following general formula (III-1):
In formula (III-1), R₂₄ signifies a phenyl group which may have one or more substituents. Typical substituents that can be introduced include the following: a halogen atom, an alkyl group, a hydroxyl group, a cyano group, a nitro group, an alkoxy group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkyloxycarbonyl group, and an aryloxycarbonyl group. Two or more of these substituents may be introduced in a phenyl group. Preferable examples of the group signified by R₂₄ are an unsubstituted phenyl group and a phenyl group that has one or more substituents selected from among a halogen atom (preferably fluorine, chlorine or bromine), an alkylsulfonamido group (preferably o-methylsulfonamido, p-octylsulfonamido or o-dodecylsulfonamido), an arylsulfonamido group (preferably phenylsulfonamido), an alkylsulfamoyl group (preferably butylsulfamoyl), an arylsulfamoyl (preferably phenylsulfamoyl), an alkyl group (preferably methyl or trifluoromethyl), and an alkoxy group (preferably methoxy or ethoxy).
In formula (III-1), R₂₅ signifies an alkyl or aryl group, each of which may have one or more substituents. Typical substituents include: a halogen atom, a hydroxyl group, a carboxyl group, an alkyl group, a cyano group, a nitro group, an alkoxy group, an aryloxy group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an aminosulfonamido group, an alkylsulfonyl group, an arylsulfonyl group, an alkylcarbonyl group, an arylcarbonyl group, an aminocarbonylamido group, a carbamoyl group and a sulfinyl group. Two or more of these substituents may be introduced.
A preferable group signified by R₂₅ is an alkyl when n₁ is 0 and an aryl when n₁ is 1 or more. A more preferable example of R₂₅ is an alkyl group having 1 - 22 carbon atoms (preferably methyl, ethyl, propyl, butyl, octyl or dodecyl) when n₁ is 0, and an unsubstituted or substituted phenyl when n_l is 1 or more. A substituted phenyl is a phenyl that has one or more substituents selected from among an alkyl group (preferably t-butyl, t-amyl or octyl), an alkylsulfonamido group (preferably butylsulfonamido, octylsulfonamido or dodecylsulfonamido), an arylsulfonamido group (preferably phenylsulfonamido), an aminosulfonamido group (preferably dimethylaminosulfonamido), and an alkyloxycarbonyl group (preferably methyloxycarbonyl or butyloxycarbonyl).
In formula (III-1), R₂₆ signifies an alkylene group which may be straight-chained or branched and have 1 - 20 carbon atoms, preferably 1 - 12 carbon atoms.
In formula (III-1), R₂₇ signifies a hydrogen atom or a halogen atom (i.e., fluorine, chlorine, bromine or iodine) and a hydrogen atom is preferred.
In formula (III-1), n₁ is 0 or a positive integer, and 0 or 1 is preferred.
In formula (III-1), X₁ signifies a divalent group such as -O-, -CO-, -COO-, -OCO-, -S0₂NR'-, -NR"SO₂NR"'-, -S-, -SO-and -SO₂-, wherein R', R" and R"' are each an alkyl group which may optionally have one or more substituents; preferable examples of X₁ are -O-, -S-, -SO-, and -S0₂.
In formula (III-1), Z₂ has the same meaning as defined for Z₂ in formula (III). If Z₂ signifies a group that can be eliminated upon reaction with the oxidized product of a color developing agent, it may be selected from those which are known in the art. Suitable examples are those which either modify the reactivity of couplers or leave couplers such as to work in an advantageous manner by performing such functions as the restraining of development or bleaching and color correction in coupler-containing coated layers or other layers in a silver halide color photographic material. Representative examples of the group that can be eliminated upon reaction with the oxidized product of a color developing agent include: a halogen atom typified by chlorine or fluorine, an alkoxy group, an aryloxy group, an arylthio group, a carbamoyloxy group, an acyloxy group, a sulfonyloxy group, a sulfonamido group, a heteroylthio group and a heteroyloxy group. Particularly preferable examples of Z₂ are a hydrogen atom and a chlorine atom. For specific information of Z₂, see Japanese Patent Application (OPI) Nos. 10135/1975, 120334/1975, 130441/1975, 48237/1979, 146828/1976, 14736/1979, 37425/1972, 123341/1975, and 95346/1983; Japanese Patent Publication No. 36894/1973; and U.S. Patent Nos. 3,476,563, 3,737,316 and 3,227,551.
Typical and specific examples of the cyan coupler represented by formula (III) are listed below but the scope of the present invention is by no means limited to these examples.
(The remaining space is left blank.)
The cyan couplers of formula (III) may be synthesized by known methods such as those described in Japanese Patent Application (O_PI) Nos. 31935/1984, 121332/1984, 124341/1984, 139352/1984, 100440/1984, 166956/1984, 146050/1984, 112038/1975, 109630/1978 and 163537/1980, and U.S. Patent No. 2,895,826.
These cyan couplers are used in silver halide emulsion layers in amounts of about 0.05 - 2 moles per mole of silver halide, and the range of 0.1 - 1 mole is preferable. In terms of the amount present in one silver halide emulsion layer, the range of 1 x 10 ^-5 to 5 x 10^-2 moles per square meter is preferable, with the range of 5 x 10^-5 to 1 x 1₀ ^-2 mole per square meter being more preferable.
The cyan couplers of formula (III) may be used either independently or in admixture. They may also be used in combination with other types of cyan couplers. It is particularly preferable that the cyan couplers of formula (III) are used in combination with cyan couplers of the following general formula (IV):
where R₂₈ is a straight-chained or branched alkyl group having 1 - 4 carbon atoms; R₂₉ is a ballast group; Z₂ has the same meaning as Z.₂ in formula (III); it is particularly preferable that R₂₈ is a straight-chained or branched alkyl group having 2 - 4 carbon atoms.
In formula (IV), R₂₈ signifies a straight-chained or branched alkyl group having 1 - 4 carbon atoms and this may have a substituent such as an acylamino group (e.g., acetylamino) or an alkoxy group (e.g., methoxy); R₂₈ is preferably an alkyl group having 2 - 4 carbon atoms.
The ballast group signified by R₂₉ is an organic group whose size and shape are such that it provides the molecule of a coupler with a sufficient bulkiness to render the coupler substantially nondiffusible from the layer in which it is incorporated to another layer. Typical ballast groups are alkyl and aryl groups which have a total carbon number of 8 to 32. These alkyl and aryl groups may have substituents. Illustrative substituents for an aryl group include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a carbosyl group, an acyl group, an ester group, a hydroxyl group, a cyano group, a nitro group, a carbamoyl group, a carbonamido group, an alkylthio group, an arylthio group, a sulfonyl group, a sulfonamido group, a sulfamoyl group, and a halogen atom. All of these substituents except an alkyl group may be used as substituents for an alkyl group.
Particularly preferable ballast groups are those which are represented by the following general formula (IV-1):
where R₃₀ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; Ar is an aryl group such as phenyl and may have a substituent. Illustrative substituents are an alkyl group, a hydroxyl group, an alkylsulfonamido group, etc. The most preferable substituent is a branched alkyl group such as t-butyl.
Specific examples of the coupler of formula (IV) are listed below but the scope of the present invention is by no means limited to these examples:

(The remaining space is left blank.)

The cyan couplers of formula (IV) may be synthesized by known methods such as those described in Japanese Patent Publication No. 11572/1974, Japanese Patent Application (OPI) Nos. 117249/1985, 205446/1985, 205447/1985 and 232550/1985, and U.S. Patent No. 4,540,657.
The cyan coupler of formula (IV) may be used in any amount so long as its ratio to the amount of the cyan coupler of formula (III) will not exceed unity. For the purpose of attaining good color reproduction, the cyan coupler of formula (IV) is used in an amount which is preferably within the range of 100 - 20 mol%, more preferably 100 - 30 mol%, of the cyan coupler of formula (III).
A particularly preferable combination of couplers used in the present invention is such that each of the yellow coupler of formula (I), magenta coupler of formula (II) and the cyan coupler of formula (III) is two-equivalent.
The present invention has been accomplished on the basis of the finding that a silver halide color photographic material providing excellent color reproduction can be attained if the yellow, magenta and cyan couplers specified above are used and if said photographic material affords a magenta y to cyan y ratio of 0.85 - 1.00 and a yellow y to cyan y ratio of 0.83 - 1.00 when it is subjected to monochromatic exposure to blue, green and red light under the conditions specified below, then developed and processed under the conditions specified below, and subsequently subjected to measurement of cyan y, magenta y and yellow Y values of the respective colors by the method specified below.
The term "excellent color reproduction" as used hereinabove does not simply mean that the purity of primary colors improved to provide the reproduction of brilliant chromatic colors; it also means that desired reproduction is attained for all colors and density regions in the actual practice of color photography and that this is ensured under varying conditions of development and other steps of photographic processing.
For the purposes of the present invention, the ratio of magenta y to cyan y is preferably within the range of 0.87 - 0.97 and the ratio of yellow y to cyan y is preferably within the range of 0.85 - 0.97.
The conditions of monochromatic exposure, the conditions of development and subsequent processing, and the method of y value measurement that are employed in the present invention are described hereinafter.

Conditions of monochromatic exposure

Conditions of development and subsequent processing

Method or y measurement

The reflection density of the image formed on a developed and subsequently processed sample is measured with a densitometer that satisfies the geometric conditions for reflection density measurement specified in JIS 7612 - 1982 and which has interference filters that feature maximum transmission wavelengths of 644 nm, 546 nm and 436 nm for the measurement of cyan, magenta and yellow reflection densities, respectively, and each of which has a half-width of no greater than 18 nm; the y value for each color is calculated by the following formula:
where E₁ and E₂ represent the amounts of exposure that are necessary to provide reflection densities of Dmin + 0.5 and Dmin + 1.8, respectively, Dmin signifying the reflection density of unexposed areas.
Cyan y, magenta y and yellow y are defined as follows:

cyan y : calculated from the reflection density measured with an interference filter of 644 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a cyan coupler of the general formula (III);
magenta y: calculated from the reflection density measured with an interference filter of 546 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a magenta coupler of the general formula (II);
yellow Y: calculated from the reflection density measured with an interference filter of 436 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a yellow coupler of the general formula (I).

The term "dominant color formation" used in the definitions of cyan y, magenta y and yellow Y is explained hereinafter with reference to a silver halide color photographic material having the layer arrangement shown below:
Suppose here that this photographic material is subjected to exposure to red light, then developed and subsequently processed by the methods described before. In this case, only the red-sensitive emulsion in the third layer should ideally undergo exposure to allow only the cyan coupler to form a color dye. In fact, however, because of the spectral absorption characteristics of the filters for monochromatic exposure and the silver halide emulsions, the blue-sensitive emulsion in the first layer and the green-sensitive emulsion in the second layer will also undergo exposure and, in response to this, the yellow and magenta couplers will also form their respective color dyes. In addition, when the red-sensitive emulsion in the third layer is exposed and subjected to color development, part of the oxidized product of a color developing agent which is to react with the cyan coupler to form a dye will diffuse into the second and first layers so as to cause a slight degree of color formation by the magenta and yellow couplers. For the reasons stated above, monochromatic exposure to red light can cause partial color formation from the couplers in the second and third layers. For the same reason, the cyan coupler in the third layer can form a color dye when monochromatic exposure to green or blue light is effected. In order to distinguish between these cases, the term "dominant color formation" is used in the present invention. Referring to the case of photographic material under discussion, the following relationships may be set forth:

Exposure to red light - dominant color formation occurs in the silver halide emulsion layer containing a cyan coupler
Exposure to green light - dominant color formation occurs in the silver halide emulsion layer containing a magenta coupler
Exposure to blue light - dominant color formation occurs in the silver halide emulsion layer containing a yellow coupler.

The present invention relates in part to a technique of using specific cyan, magenta and yellow couplers, which is already described in several patents such as, for example, Japanese Patent Application (OPI) Nos. 222852/1985 and 229029/1985. They have reference to the color balance of dye images when faded or to the colors of individual dyes; however, none of these prior patents suggest the other part of the present invention which relates to a technique for providing improved color reproduction by attaining a balance between the y values of specific colors.
Let us now describe the relationship between the balance in y values and the accomplishment of good color reproduction. The balance of y values is a factor that determines the color balance of a photographic image and it is particularly necessary that an appropriate balance of y values be attained in order to reproduce neutral colors. Therefore, theorectically, neutral colors can be reproduced in a desired manner by selecting an appropriate combination of the y values of cyan, magenta and yellow colors. However, it will require a great amount of labor to actually determine the desired combination by an empirical method, for example, on a trial-and-error basis. Should the researcher be lucky enough to attain a reasonably acceptable set of conditions fortuitously, there would be no guarantee that these conditions will enable the production of high-quality images in the face of the versatility of commercial market, for example, under varying levels of development and subsequent processing (it is generally known that variations in the level of development and subsequent processing will lead to a change in the y values of a photographic material and/or their balance). Therefore, it is not very easy to determine an optimum combination of y values experimentally, albeit possible theoretically.
According to the present invention, cyan, magenta and yellow couplers of formulas (I), (II) and (III), respectively, are selected and light-sensitive silver halide emulsion layers containing these couplers are coated in superposition on a support such that the y values of the couplers can be controlled independently of one another to attain the ratios of y values that are within the ranges specified by the present invention. As a result, a silver halide color photographic material that is capable of excellent color reproduction can be produced, thereby contributing a significant advantage to the photographic industry.
The silver halide color photographic material of the present invention is superior not only in the reproduction of neutral colors but also in the reproduction of monochromatic colors. One reason for this advantage is that as already mentioned, the photographic material of the present invention uses couplers that are desirable from the view-point of color reproduction. When samples of this photographic material were actually made, they were found to provide far superior reproduction of monochromatic colors than expected from the sole effects of the couplers. This unexpected advantage will most probably have resulted both from the combined use of the couplers specified by the present invention and from the limitation of the ratios of y values for the respective coupler-containing layers to be within the ranges also specified by the invention.
In order to prepare the silver halide color photographic material of the present invention, the specified ratios of y values must be attained by properly adjusting the gradation of the three silver halide emulsions containing cyan, magenta and yellow couplers. While a variety of conventional techniques may be employed for gradation adjustment, the following method is preferably employed in the present invention.
The basic means for implementing the preferred method of gradation adjustment consists of varying the coating weights of silver and couplers. Generally, a higher coating weight of silver or a coupler produces a hard gradation, and vice versa. This method enables gradation adjustment over the full range of exposure, i.e., from low to high exposure. The following table shows the conditions which are preferably employed in the practice of this method.
More preferable conditions that will provide the advantages of the present invention in a more pronounced way and which take into account the production cost and other characteristics are shown below.
A preferable alternative to the method for gradation adjustment that depends on the adjustment of the coating weights of silver and couplers consists of using a combination of silver halide emulsions that are sensitive to the same color but have different sensitivities in each of the silver halide emulsion layers containing the yellow, magenta and cyan couplers specified by the present invention.
In this case, a plurality of such silver halide emulsions may be mixed together for incorporation in the same emulsion layer or they may be contained in separate emulsion layers that are sensitive to the same color. Alternatively, a plurality of silver halide emulsions that are sensitive to the same color and have substantially the same sensitivity but which have different levels of gradation may be used in combination.
If the method of gradation adjustment that depends on the combined use of silver halide emulsions is used in combination with the first method of gradation adjustment which relies on the adjustment of the coating weights of silver and couplers, the scope of applicability of the latter method can be further expanded.
The second method which involves the combined use of silver halide emulsions is preferably carried out using monodispersed emulsions of the type to be described later in this specification since it allows for reliable and easy gradation design.
When the adjustment of the coating weights of silver and couplers is performed either independently or in combination with the combined use of silver halide emulsions as basic means of gradation adjustment, it is preferable to employ the following auxiliary means for the purpose of permitting these basic means to achieve their intended effects in a reliable and easy manner.
One technique that is preferably employed to implement this auxiliary means of gradation adjustment is to use a compound represented by the following general formula (V):
where Zo signifies the group of atoms that is necessary to form a hetero ring.
Examples of the hetero ring that is formed by Zo include the following: an imidazoline ring, an imidazole ring, an imidazolone ring, a pyrazoline ring, a pyrazole ring, a pyrazolone ring, an oxazoline ring, an oxazole ring, an oxazolone ring, a thiazoline ring, a thiazole ring, a thiazolone ring, a selenazoline ring, a selenazole ring, a selenazolone ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a benzimidazole ring, a benzotriazole ring, an indazole ring, a benzoxazole ring, a benzothiazole ring, a benzoselenazole ring, a pyradine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, an oxazine ring, a thiazine ring, a tetrazine ring, a quinazoline ring, a phthalazine ring, and a polyazaindene ring (e.g., triazaindene, tetrazaindene or pentazaindene ring).
The heterocyclic residue represented by
in formula (V) may have a substituent such as, for example, an alkyl group, an aryl group, an alkenyl group, a sulfamoyl group, a carbamoyl group or an acyl group.
Particularly preferable mercapto heterocyclic compounds of the formula (V) are mercaptotriazole-based compounds which contain a triazole ring.
Specific examples of the compound of formula (V) are listed below but it should be noted that the scope of the present invention will by no means be limited by these examples.
(The remaining space is left blank.)
Several examples of the compounds of formula (V) which are preferably used in the present invention are shown in prior art references such as, for example, Japanese Patent Publication Nos. 42974/1973 and 51666/1982, Japanese Patent Application (OPI) No. 102621/1973, French Patent Nos. 701,053, 701,301 and 1,563,019, U.S. Patent No. 3,457,078, and The Journal of Photographic Science, 19, pp. 83 - 87.
When compounds of formula (V) are incorporated in silver halide emulsion layers containing the yellow, magenta and cyan couplers specified by the present invention, the general results attained are reduced fog and a softer gradation in the low-density region. If compounds of formula (V) are incorporated in intermediate layers or other layers that are adjacent to the silver halide emulsion layers, the ability of the compounds to provide a softer gradation is usually decreased but their capability of reducing the amount of fog is retained. Therefore, in certain cases where an excessively soft gradation will result if those compounds are used in the silver halide emulsions in the amounts necessary to suppress fogging, controlled amounts of the compounds may be incorporated both in the silver halide emulsion layers and in adjacent layers with a view to maintaining an appropriate level of fogging and yet achieving the desired gradation.
As mentioned above, if compounds of formula (V) are used, the gradation of low-density areas can be controlled to desired values and yet the fogging can be maintained at appropriate levels.
Compounds of formula (V) are added to silver halide emulsion layers containing the yellow, magenta and cyan couplers specified by the present invention, and optionally in layers adjacent to these emulsion layers. The amounts in which such compounds are added are not critical so long as they can attain the intended effects; but usually they are added in a total amount of 5 x 10 6 to 5 x 1₀ ³ g/m² in the coatings on a support.
Compounds of formula (V) may be added by any of the methods commonly employed to incorporate photographic additives; for instance, they may be added in the form of solutions in water, an aqueous acidic or alkaline solution having a suitable pH, or in an organic solvent such as methanol or ethanol.
A more preferable method for implementing the auxiliary means of gradation adjustment consists of using a compound represented by the following general formula (VI) and/or a compound represented by the following general formula (VII):
(where R₃₁, ^R ₃₂, R₃₃ and R₃₄ each signifies a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group,-an aryl group, a cycloalkyl group, a hetero ring, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, an alkylacylamino group, an arylacylamino group, an alkylcarbamoyl group, an arylcarbamoyl group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a nitro group, a cyano group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylacyloxy group or an arylacyloxy group; provided that at least one of ^R ₃₁ to R₃₄ is a group having a total of at least 6 carbon atoms);
(where R₄₁ is an alkyl group having 1 - 5 carbon atoms; and R₄₂ is a hydrogen atom or an alkyl group having 1 - 5 carbon atoms).
The group represented by each of R₃₁ to R₃₄ in formula (VI) may have a substituent such as an alkyl, aryl, aryloxy, alkylthio, cyano, acyloxy, alkoxycarbonyl, acyl, sulfamoyl, hydroxy, nitro, amino or a heterocyclic group; at least one of ^R ₃₁ to R₃₄ is a group that has a total of at least 6 carbon atoms, inclusive of the substituents listed above.
Among the compounds of formula (VI), those which are represented by the following general formula (VI-1) are used more preferably:
where R₃₅ and R₃₆ are each a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an acyl group, a cycloalkyl group or a heterocyclic group, provided that at least one of R₃₅ and R₃₆ is a group having a total of at least 6 carbon atoms.
The alkyl group signified by R₃₅ or R₃₆ in formula (VI-1) may be illustrated by methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, n-amyl, i-amyl, n-octyl, n-dodecyl or n-octadecyl, with alkyl groups having 1 - 32 carbon atoms being particularly preferable.
The alkenyl group signified by R₃₅ or ^R ₃₆ may be illustrated by allyl, octenyl or oleyl, with alkenyl groups having 2 - 32 carbon atoms being particularly preferable.
The aryl group signified by R₃₅ or R₃₆ may be exemplified by phenyl or naphthyl; the acyl group as R₃₅ or R₃₆ may be illustrated by acetyl, octanoyl or lauroyl; the cycloalkyl group as R₃₅ or R₃₆ may be illustrated by cyclohexyl or cyclopentyl; and examples of the heterocyclic group signified by R₃₅ or R₃₆ include imidazolyl, furyl, pyridyl, triazinyl and thiazolyl.
At least one of R₃₅ and R₃₆ in formula (VI-1) is preferably a group that has a total of at least 8 carbon atoms; more preferably, both R₃₅ and R₃₆ are a group having a total of 8 - 18 carbon atoms, and most preferably, both R₃₅ and R₃₆ are the same group having a total of 8 - 18 carbon atoms.
Specific examples of the compound of formula (VI) are listed below, to which the scope of the present invention is by no means limited.
(The remaining space is left blank.)
For more information of these compounds, see Research uisclosure, No. 17643 (1983), VII-I.
In formula (VII), R₄₁ signifies an alkyl, which may be straight-chained or branched, having 1 - 5 alkyl groups; preferably, R₄₁ is an alkyl group having 2 - 5 carbon atoms. In formula (VII), R₄₂ is a hydrogen atom or an alkyl group having 1 - 5 carbon atoms, which may be the same as any one of the alkyl groups listed for use as k₄₁; preferably, R₄₂ is an alkyl group having 1 - 5 carbon atoms, more preferably 2 - 5 carbon atoms.
In formula (VII), R₄₁ and R₄₂ are preferably the same group and, more preferably, R₄₂ is situated in the position para to R₄₁.
Specific examples of the compound of formula (VII) are given below, to which the scope of the present invention is by no means limited.
Each of the compounds of formulas (VI) and (VII) is effective for the purpose of preventing color fogging and controlling the gradation of low-density areas. If these compounds are oil-soluble, they may be dissolved in appropriate high-boiling organic solvents and added as a dispersion of the oil-in-water type. In this case, the compounds may be dispersed simultaneously with or separately from the couplers. If the compounds are water-soluble, they may be added after dissolved in water-miscible organic solvents or aqueous alkaline solutions.
Depending upon the type, amount of addition and other aspects of the compounds of formulas (VI) and (VII), the photographic material may suffer from a problem in its performance such as image stability in a light place. With sufficient care being taken to avoid this problem, the amounts of compounds of formula (VI) and/or (VII) necessary to attain the desired gradation may be incorporated in the silver halide emulsion layers containing the yellow, magenta and cyan couplers specified by the present invention and/or in adjacent non-sensitive layers such as intermediate layers. In this case, both compounds of formulas (VI) and (VII) are preferably used because the relationship between gradation adjustment and photographic performance is sufficiently improved to expand the range over which desired gradation adjustment can be accomplished. There is no particular limitation on the amount in which the compounds of formulas (VI) and (VII) can be added but, in consideration of their effects on the storage stability of dye images and other aspects of photographic performance, compounds of formula (VI) are preferably added in a total amount of 1 x 10^-4 to 2 g/m², more preferably 5 x 10^-3 to 1 g/m², in the coatings on a support, and compounds of formula (VII) are preferably added in a total amount of 1 x 10 to 1.5 g/m², more preferably 2 x 10³ to 0.7 g/m², in the coating on a support.
The above-described methods of gradation adjustment may optionally be used in combination with other methods of gradation adjustment.
The yellow, magenta and cyan couplers specified by the present invention are preferably used in combination with monodispersed emulsions for attaining the following purposes:

1) gradation design by the method that relies on the combined use of silver halide emulsions is facilitated and, in addition, the relative sensitivity of green- and red-sensitive emulsions to blue light is reduced by employing monodispersed emulsions as these emulsions, so as to reduce undesired color contamination and, hence, to provide a silver halide color photographic material having improved color reproduction; and 2) by making use of the potential for fine-grained emulsions having higher sensitivities, significant improvements can be achieved in development, pressure resistance (ie, the photographic material will undergo reduced deterioration of its performance, such as less desensitization and fogging, in the presence of applied pressure) and other photographic characteristics, such as to produce a silver halide color photographic material that generally provides high-quality images.

The term "monodispersed emulsions" as used hereinabove means a silver halide emulsion that is composed of silver halide grains that have very small variations in grain shape, grain size, and silver halide composition as between individual grains. As for the grain size distribution, it is preferable that the coefficient of variation defined below will not exceed 0.20, and the advantages of the present invention will be attained in a more pronounced manner if that coefficient is 0.15 or below:
where

(where ri signifies the size of individual grains, and ni is the number of those grains).
The term "grain size" as used hereinabove is expressed as the diameter if a silver halide grain of interest is spherical, and as the diameter of an equivalent circle for the projected image of the grain if its shape is non-spherical.
The grain shape distribution is preferably such that when silver halide brains of interest are observed under an electron microscope, the number of grains that have anomalous shapes is no more than 10, preferably no more than 1, for 1,000 grains found within the field of vision.
The distribution of silver halide composition between grains may be evaluated on the basis of examination of the silver halide compositions of individual grains with an X-ray microanalyzer; preferably, at least 50% of the projected areas of all silver halide grains examined should have a deviation from the average composition that is not greater than 30%, preferably, not greater than 20%.
Monodispersed emulsions having the features described above may be used independently or, if desired, in combination with other monodispersed emulsions or with polydispersed emulsions.
When the monodispersed emulsions described above are used in mixture with other types of emulsion, a greater advantage may be attained by employing the technique disclosed in Japanese Patent Application (OPI) Nos. 225141/1985 and 225142/1985.
The average grain size of the silver halide emulsions used in the present invention is not limited to any particular value but, in consideration of such factors as the progress of development, stability under varying conditions of processing and color reproduction, the silver halide emulsions preferably have an average grain size of 0.1 - 2 um, more preferably 0.2 - 1.5 pm.
There is also no particular limitation on the silver halide composition of the silver halide emulsions used in the present invention but it is preferable that they are substantially silver chlorobromide emulsions with low silver iodide contents. A substantially silver chlorobromide emulsion is a silver halide emulsion that contains silver halide grains whose silver halide composition is such that the content of silver iodide is less than 1 mol%, with the remainder being composed of silver chloride and silver bromide. In view of several factors such as developability and desilvering, the silver iodide content is preferably as low as possible; in particular, green- and red-sensitive silver halide emulsions should preferably have low silver iodide contents in order to suppress their sensitivity to blue light and to achieve better color reproduction. For the same reason, green- and red-sensitive silver halide emulsions preferably have the highest possible silver chloride content.
The silver halide grains used in the present invention preferably have a silver chloride content of at least 5 mol%, more preferably at least 15 mol%.
The silver halide grains used in the present invention may have a homogeneous structure throughout the grain, or the structure of the core may be different from that of the shell. In the latter case, the compositional change may be continuous or discontinuous.
Soluble silver salts may be reacted with soluble halide salts by any techniques such as the normal mixing method, the revrese mixing method and the double-jet method, the last-mentioned method being preferable. Monodispersed silver halide grains may be prepared by the pAg controlled double-jet method which is described in Japanese Patent Application (OPI) No. 48521/1979 as one version of the double-jet method.
If necessary, silver halide solvents such as thioether, or crystal habit controlling agents such as mercapto- containing compounds and sensitizing dyes may also be used.
The silver halide grains to be used in the present invention may have metal ions incorporated inside the grains and/or in the grain surfaces in the course of forming and/or growing the grains by using cadmium salt, zinc salt, lead salt, thallium salt, iridium salt or its complex salt, rhodium salt or its complex salt, or iron salt or its complex salt. Said grains may also be placed in an appropriate reduction atmosphere to have reduction-sensitized specks imparted inside the grains and/or into the grain surfaces.
The silver halide emulsions of the present invention may be freed of unnecessary soluble salts after completion of the growth of the silver halide grains or may be left as they are containing such salts.
The silver halide grains used in the present invention may have any crystallographic shapes; they may be regular or irregular such as being spherical or tabular. These crystals may have any surfaces such as {100} , {111} and {110} planes and the proportions of these planes may assume any values. Grains that are particularly preferable for use in the present invention are octahedral, tetradecahedral and cubic grains that have regular crystallographic shapes whose surfaces are composed of {100} and/or {111} planes.
The silver halide grains used in the present invention is chemically sensitized by an ordinary method, such as sulfur sensitization using a compound containing sulfur which is capable of reaction with silver ions or using active gelatin, selenium sensitization using a selenium compound, reduction sensitization using a reducing material, or noble metal sensitization using gold and other noble metal compounds. Such methods may be used either independently or in combination.
The silver halide grains used in the present invention may be spectrally sensitized by suitably selected sensitizing dyes in order to provide sensitivity for the desired spectral wavelength regions.
In order to prevent the occurrence of fog and/or keep the photographic properties stable in the course of preparing the photographic material or during storage or processing thereof, a compound known in the photographic industry as an antifoggant or stabilizer may be added to the silver halide grains to be used in the present invention in the course of chemical ripening and/or upon completion of chemical ripening and/or after completion of chemical ripening but before the coating of silver halide emulsions.
The aforementioned silver halide emulsions that are preferably used in the present invention may be prepared with reference being made to the specific techniques described in such prior patents as Japanese Patent Application (OPI) Nos. 225145/1985, 225146/1985, 225147/1985, 225154/1985 and 232545/1985.
Hydrophobic compounds such as the yellow, magenta and cyan couplers specified by the present invention may be dispersed into emulsions by means of vaious methods such as solid dispersion, latex dispersion or oil-in-water drop type emulsion dispersion. Such dispersion methods can be . appropriately selected according to the chemical structure and the like of the hydrophobic compounds. The oil-in-water drop type emulsion dispersion method may be any conventional method of dispersing hydrophobic additives such as couplers, which usually comprises dissolving such hydrophobic additives in a high-boiling organic solvent having a boiling point higher than about 150°C, with low-boiling and/or water-soluble organic solvents being optionally used together, then emulsion-dispersing the dissolved hydrophobic additives in the presence of a surfactant in a hydrophilic binder such as an aqueous gelatin solution with such means of dispersion as a stirrer, homogenizer, colloid mill, flow- jet mixer or ultrasonic disperser, and thereafter adding the resulting dispersion into a hydrophilic colloidal layer of interest. In that case, the step of removing the low-boiling organic solvent after or simultaneously with the step of dispersion may be included.
Dispersion aids may be used in dissolving hydrophobic compounds in low-boiling solvents used either alone or in combination with high-boiling organic solvents, then dispersing the dissolved hydrophobic compounds in water by mechanical means or with ultrasonic waves; suitable dispersion aids include anionic surfactants, nonionic surfactants and cationic surfactants.
High-boiling organic solvents which are used as media for dispersing the yellow, magenta and cyan couplers specified by the present invention are preferably selected from among the compounds having dielectric constants'of no higher than 6.0 at 30°C. There are no particular lower limits for the dielectric constants of such compounds but they preferably have dielectric constants of at least 1.9. Illustrative compounds are those which have dielectric constants of no more than 6.0 such as esters (e.g. phthalate esters and phosphate esters), organic acid amides, ketones and hydrocarbon compounds. Phthalate esters and phosphate esters are more preferable. Two or more high-boiling organic solvents may be used in mixture and, in this case, the resulting mixture preferably has a dielectric constant of 6.0 or below. High-boiling organic solvents that can be used in combination in the present invention include dibutyl phthalate, dimethyl phthalate, tricresyl phosphate, tributyl phosphate, etc.
Phthalate esters that may be used advantageously in the present invention are represented by the following general formula (VIII):
where R₅₁ and R₅₂ each signifies an alkyl, alkenyl or aryl group, provided that the total number of carbon atoms in the group signified by R₅₁ or R₅₂ ranges from 9 to 32, preferably from 16 to 24.
The alkyl group signified by R₅₁ or R₅₂ in formula (VIII) may be straight-chained or branched. The alkyl, alkenyl or aryl group signified by R₅₁ or R₅₂ may have one or more substituents; substituents for the alkyl or alkenyl group include a halogen atom, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, an alkoxycarbonyl group, etc.; substituents for the aryl group include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, an alkoxycarbonyl group, etc. Two or more of these substituents may be introduced in the alkyl, alkenyl or aryl group.
Phosphate esters that may be used advantageously in the present invention are represented by the following general formula (IX):
where R₅₃, ^R ₅₄ or R₅₅ each signifies an alkyl, alkenyl or aryl group, provided that the total number of carbon atoms in the group signified by R₅₃, ^R ₅₄ or ^R ₅₅ ranges from 24 to 54.
The alkyl, alkenyl or aryl group signified by R₅₃, ^R ₅₄ or R₅₅ in formula (IX) may have one or more substituents; preferably, R₅₃, R₅₄ and R₅₅ are each an alkyl group such as 2-ethylhexyl, n-octyl, 3,5,5-trimethylhexyl, n-nonyl, n-decyl, sec-decyl, sec-dodecyl or t-octyl.
Preferable high-boiling organic solvents are specifically listed below:

Illustrative high-boiling organic solvents

(The remaining space is left blank.)
These high-boiling organic solvents are generally used in amounts ranging from 10 to 150 wt%, preferably from 20 to 100 wt%, of each of the couplers specified by the present invention.
Image stabilizers may be incorporated in the silver
(The remaining space is left blank.)
halide color photographic material of the present invention in order to prevent deterioration of color images.
Image stabilizers that are preferably used in the present invention include: the compounds represented by the general formula (A) on page 101 of the specification of Japanese Patent Application No. 117493/1985 (specifically exemplified by A-I to A-32 on pages 109 - 116), the compounds represented by the general formula (B) on page 117 of the same specification (specifically exemplified by B-1 to B-55 on pages 123 - 127), the compounds represented by the general formula (C) on page 128 of the same specification (specifically exemplified by C-1 to C-17 on pages 133 and 134), the compounds represented by the general formula (D) on page 128 of the same specification (specifically exemplified by D-1 to D-11 on pages 135 and 136), the compounds represented by the general formula (E) on page 137 (specifically exemplified by E-1 to E-42 on pages 143 - 147), the compounds represented by the general formula (F) on page 148 of the same specification (specifically exemplified by F-1 to F-47 on pages 155 - 159), the compounds represented by the general formula (G) on page 160 of the same specification (specifically exemplified by G-1 to G-45 on pages 164 - 166), the compounds represented by the general formula (H) on page 167 of the same specification (specifically exemplified by H-1 to H-36 on pages 171 - 174), the compounds represented by the general formula (J) on page 175 of the same specification (specifically exemplified by J-1 to J-74 on pages 178 - 183), the compounds represented by the general formula (K) on page 188 of the same specification (specifically exemplified by K-1 to K-41 on pages 193 - 197), the compounds represented by the general formulas (L) and (M) on page 198 of the same specification (specifically exemplified by L-1 to L-20 on pages 204 - 210 and by M-1 to M-3 on page 211), and the compounds represented by the general formula (N) on page 212 of the same specification (specifically exemplified by N-1 to N-107 on pages 223 - 249).
These image stabilizers may be incorporated in any layer but they are preferably incorporated in a silver halide emulsion layer containing the magenta coupler of formula (II) specified by the present invention. There is also no particular limitation on the amount in which the image stabilizers are added but the preferable range is from 2 to 16 mg/dm².
Gelatin is advantageously used as a binder (or protective colloid) for emulsion layers that contain the silver halide grains used in the present invention. Aside from gelatin, other hydrophilic colloids may be used and they include gelatin derivatives, graft polymers of gelatin with other high-molecular weight substances, proteins, sugar derivatives, cellulosic derivatives, and synthetic hydrophilic high-molecular weight substances such as homo- and copolymers.
Photographic emulsion layers and other hydrophilic colloidal layers in the silver halide color photographic material of the present invention (hereinafter referred to as the light-sensitive material of the present invention) are hardened with hardeners that are used either alone or in combination to bridge the molecule of the binder (or protective colloid) to provide an enhanced film strength.
The hardener is desirably added in such an amount as is capable of hardening the photographic material to the extent that there is no need to add the hardener in the processing solution, but such hardener may be added in the processing solution.
A plasticizer can be added with a view to enhancing the flexibility of the silver halide emulsion layers and/or other hydrophilic colloidal layers in the light-sensitive material of the present invention.
For attaining such purposes as an improvement of dimensional stability, dispersions (latices) of water-insoluble or slightly water-soluble synthetic polymers may be incorporated in photographic emulsion layers and other hydrophilic colloidal layers in the light-sensitive material using the silver halide emulsions of the present invention.
The advantages of the silver halide color photographic material of the present invention will be exhibited in an effective manner if it is used as color paper which is intended for direct viewing of image.
The silver halide color photographic material of the present invention which is typically used as color paper is intended to achieve color reproduction by the subtractive processes and, hence, has such a structure that silver halide emulsion layers containing the magenta, yellow and cyan couplers specified by the present invention, as well as non-light-sensitive layers are coated in superposition on a support, with the number and sequence of layers being appropriately changed according to the importance of a certain aspect of performance and the specific object of use.
In a particularly preferable embodiment, the silver halide color photographic material of the present invention comprises, in order from the support side, a yellow-dye image forming layer, an intermediate layer, the magenta-dye image forming layer of the present invention, an intermediate layer, a cyan-dye image forming layer, an intermediate layer, and a protective layer, which are coated as separate layers on the support.
The hydrophilic colloidal layers such as protective layers and intermediate layers in the color photographic material of the present invention may have incorporated therein UV absorbers in order to prevent the occurrence of fogging due to discharge resulting from the photographic material being charged by friction or the like, or to prevent the deterioration of images due to UV light.
The silver halide color photographic material of the present invention can be provided with auxiliary layers such as filter layers, anti-halation layers and/or anti-irradiation layers. These auxiliary layers and/or the emulsion layers may have incorporated therein dyes that will flow out of the color photographic material or which will be bleached during development or subsequent processing.
Matting agents may be incorporated in silver halide emulsion layers and/or other hydrophilic colloidal layers in the silver halide color photographic material of the present invention, with a view to attaining such purposes as reducing the surface gloss of the light-sensitive material, enhancing the writability in pencil, and preventing the adhesion of light-sensitive materials to each other.
The silver halide color material of the presentinven- tion may contain a lubricant that is capable of reducing its sliding friction.
The silver halide color material may also contain an antistat for the purpose of preventing static buildup. The antistat may be incorporated in an antistatic layer on the side of the support where no emulsion layer is formed. Alternatively, the antistat may be incorporated in an emulsion layer and/or a protective layer.
Photographic emulsion layers and/or other hydrophilic colloidal layers in the light-sensitive material using the silver halide emulsions of the present invention may contain a variety of surfactants for attaining such purposes as improved coating property, prevention of antistatic buildup, improved slipping property, emulsification/dispersion, antiblocking and improved photographic characteristics in terms of accelerated development, hard gradation and sensitization.
Photographic emulsion layers and other layers for making the silver halide photographic material of the present invention may be coated onto flexible reflecting supports such as baryta paper, paper laminated with a-olefin polymers, and synthetic paper, films made of semi-synthetic or synthetic polymers such as cellulose acetate, cellulose nitrate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate and polyamide, and rigid materials such as glass, metals and ceramics. Among these supports, reflective supports are preferable and may be exemplified by paper that is laminated with a polymer such as polyethylene that is loaded with a white pigment such as titanium oxide.
After optional surface treatment of the support by suitable techniques such as corona discharge, UV irradiation and flame treatment, the silver halide color photographic material of the present invention may be coated onto the suppot either directly or with one or more subbing layers formed thereon. The subbing layers are provided for improving the adhesive strength, anti-static property, dimensional stability, wear resistance, hardness, anti-halation property, frictional characteristics and/or other characteristics of the surface of the support.
A thickener may be used in order to facilitate the coating of the silver halide color photographic material of the present invention. Particularly_useful coating techniques are extrusion coating and curtain coating, both of which will enable simultaneous application of two or more layers.
The silver halide photographic material of the present invention may be exposed to electromagnetic waves in the spectral region to which the emulsion layers that make up the photographic material have sensitivity. Any known light sources may be used and they include daylight (sunshine), tungsten lamps, fluorescent lamps, mercury lamps, xenon arc lamps, carbon arc lamps, xenon flash lamps, CRT flying spot, light from a variety of lasers, LED emitted light, and light emitted from fluorescent materials upon excitation by electron beams, X-rays gamma-rays or alpha-rays.
The exposure time may range from 1 millisecond to 1 second as is usually the case with cameras. Periods shorter than 1 microsecond, such as one ranging from 100 microseconds to 1 microsecond may be employed with CRTs or xenon flash lamps. Exposure longer than 1 second would also be possible. The exposure may be continuous or intermittent.
The silver halide photographic material of the present invention may form an image by any techniques of color development that are known in the art.
As will be apparent from the foregoing description, the present invention provides a silver halide color photographic material that ensures the reproduction of the colors of all scenes to be encountered in the actual practice of color photography.

EMBODIMENTS OF THE INVENTION

The following examples are provided for the purpose of further illustrating the present invention but should in no sense to be taken as limiting.

Example 1

Samples (Nos. 1 to 8) of silver halide color photographic material having the basic composition shown in Table 1 were prepared by common procedures. In order to control the ratios of y values for the three colors, cyan, magenta and yellow, the coating weights of silver and coupler in the third layer of each sample were varied as shown in Table 2.
The figures in parentheses indicate coating weights or amounts added.
Compounds, A and B, and ultraviolet absorbers, UV-1, shown in Table 1 had the following structures:
Ultraviolet absorber, UV-1
Sample Nos. 1 to 8 were processed under the conditions to be described below and the values for cyan, magenta and yellow colors obtained by monochromatic exposure to red, green and blue light were determined for each sample. Thereafter, the ratio of the y value of the yellow coupler containing layer to the y value of the cyan coupler containing layer (Y/C) and the ratio of the y value of the magenta coupler containing layer to the y value of the cyan coupler containing layer (M/C) were calculated for each sample and the results are shown in Table 2.
Sample Nos. 1 to 8 were also subjected to evaluation of color reproduction by the method also specified below. The results are also shown in Table 2.

Conditions of monochromatic exposure

(1) exposure to red light
(2) exposure to green light
(3) exposure to blue light

Provided that exposure through a neutral step tablet was performed in each of (1), (2) and (3) in order to achieve variation in the amount of exposure;

Conditions of development and subsequent processing

(1) scheme (steps and the duration of their times)
(2) Composition of processing fluids

(color developing solution)

(bleach-fixing solution)

Method of Y measurement

cyan y : calculated from the reflection density measured with an interference filter of 644 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a cyan coupler of the general formula (III);
magenta y:calculated from the reflection density measured with an interference filter of 546 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a magenta coupler of the general formula (II);
yellow y: calculated from the reflection density measured with an interference filter of 436 nm in the densitometer for a sample in which dominant color formation occurred in a silver halide emulsion layer containing a yellow coupler of the general formula (I).

Method of evaluating color reproduction

The standard color chips, 5R, 5YR, 5Y, 5GY, 5G, 5BG, 5B, 5PB, 5P and 5RP, that were prepared in accordance with JIS Z 8721 were shooted under daylight to make color negative films on Sakura Color SR-100 with KONIKA FS-1. The negatives were printed on sample Nos. 1 to 8, with color correcting filters being adjusted such that a patch for an achromatic color chip having a V value (a measure of lightness) of 40 would reproduce a substantially neutral color. Thereafter, the prints were developed and subsequently processed under the same conditions as those employed for determining Y values in accordance with the present invention. By these procedures, specimens for evaluation of color reproduction were prepared.
The tone of the patch giving the highest chroma at each level of lightness was measured for each color specimen with a color analyzer, Model 607 of Hitachi, Ltd. Based on the measured values, L", u' and v' values were determined by the method specified in JIS Z 8729 and the u' and v' values of the patch corresponding to an L^* value of about 40 were plotted on a chromaticity diagram.
The area of the region bounded by the plots on the chromaticity diagram (as obtained by connecting with straight lines the points adjacent to chromatic colors) was determined to obtain a region of color reproduction. The area of this region was used as a measure of evaluation of color reproduction; the larger this area, the better the color reproduction that was attained.
Table 2 shows that improved color reproduction was attained when the two ratios of y values, Y/C and M/C, were controlled to be within the ranges specified for the present invention by adjusting the coating weights of silver and couplers.

Example 2

Sample Nos. 9 to 14 of silver halide color photographic material were prepared as in Example 1 except that the first and third layers shown in Table 1 were modified as follows:

First layer

(The two emulsions, EMB-1 and EMB-2, were mixed in the proportions indicated in Table 3 and applied for a total silver deposit of 0.3₅ g/_m ².)
High-boiling point organic solvent S-6: 0.3 g/m²

Third layer

Gelatin
High-boiling point organic solvents S-2: 0.25 g/m²
The two ratios of y values, Y/C and M/C, were determined for each of sample Nos. 9 to 14 and their color reproduction evaluated by the same methods as used in Example 1. The results are summarized in Table 3 below.
Table 3 shows that improved color reproduction was attained when the two ratios of y values, Y/C and M/C, were controlled to be within the ranges specified for the present invention by adjusting the mixing proportions of two silver halide emulsions that were sensitive to the same color but which had different sensitivities.

Example 3

Four monodispersed silver chlorobromide emulsions having the characteristics shown in Table 4 were prepared by performing the double-jet method in the presence of aqueous solution containing 3% inactivated gelatin.
Observation with an electron microscope showed that each of the four emulsions was monodispersed in that it was substantially free from any anomalously shaped grains and was uniform in grain size and morphology.
Of the four emulsions prepared, EM-1 and EM-2 were chemically ripened with sodium thiosulfate and a sensitizing dye D-1 (for its structure, see below), and upon completion of the chemical ripening, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene was added so as to make blue-sensitive emulsions, EMB-3 and EMB-4.
A part of EM-3 was chemically ripened with sodium thiosulfate and a sensitizing dye D-2 (for its structure, see below), and upon completion of the chemical ripening, 4-hydroxy--6-methyl-1,3,3a,7-tetrazaindene and a compound of formula (V) (No. 13; 20 mg/mole of silver halide) were added so as to make a green-sensitive emulsion, EMG-1.
Emulsion EM-4 was chemically ripened with sodium thiosulfate and a sensitizing dye D-3 (for its structure, see below), and upon completion of the chemical ripening, 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene were added so as to make a red-sensitive emulsion, EMR-1.
Using the four chemically sensitized emulsions, a comparative sample of silver halide color photographic material was prepared; the composition of this sample, referred to as Sample No. 15, is identified in Table 5 below. The blue-sensitive emulsion in the first layer was composed of a mixture of EMB-3 and EMB-4 so as to provide an appropriate gradation in the low-density areas.
The three sensitizing dyes, D-1, D-2 and D-3, had the following structures:
The figures in parentheses indicate coating weights or amounts added; for ^*, see Table 2.
Comparative yellow coupler, CY-1, comparative magenta coupler, CM-1, and ultraviolet absorber, UV-2, shown in Table 5 had the following structures:

Ultraviolet absorber, UV-2

Comparative sample Nos. 16 to 24 and sample Nos. 25 to 27 of the present invention were prepared as in the preparation of Sample No. 15 except that the yellow, magenta and cyan couplers and silver deposit for the first, third and fifth layers were changed to those indicated in Table 6. When the silver deposit for the blue-sensitive emulsion in the first layer was changed, the ratio of EMB-3 to EMB-4 in terms of silver was held constant.
Sample Nos. 15 to 27 thus prepared were processed as in Example 1 and the y values for cyan, magenta and yellow colors obtained by monochromatic exposure to red, green and blue light were determined for each sample. Thereafter, the ratio of the y value of the yellow-coupler containing layer to the y value of the cyan-coupler containing layer (Y/C) and the ratio of the y value of the magenta-coupler containing layer to the y value of the cyan-coupler containing layer (M/C) were calculated for each sample and the results are shown in Table 6.
Sample Nos. 15 to 27 were subjected to evaluation of color reproduction by the same method as employed in Example 1. The results are also shown in Table 6.
The data in Table 6 reveal the following: as compared with comparative sample No. 15 wherein all of the yellow, magenta and cyan couplers were comparative couplers, comparative sample Nos. 16 to 19 wherein at least one of the yellow, magenta and cyan couplers was within the scope of the present invention achieved some improvement in color. reproduction, albeit the improvement was not completely satisfactory; comparative sample Nos. 15 to 18 satisfied the requirements for the ratios of y values specified by the present invention but the color reproduction achieved by these samples was still unsatisfactory; comparative sample Nos. 19 to 24 used yellow, magenta and cyan couplers that were within the scope of the present invention but these samples did not satisfy the requirements for the ratios of y values specified by the present invention and, hence, failed to achieve satisfactory color reproduction; on the other hand, significant improvement in color reproduction was achieved by sample Nos. 25 to 27 which employed yellow, magenta and cyan couplers that were within the scope of the present invention and which also satisfied the requirements for the ratios of y values specified by the present invention.
It is therefore clear that the improvement in color reproduction achieved by the present invention is due to the synergism of the following two features: cyan, magenta and yellow couplers that are within the scope of the present invention are used; and the ratios of y values for the three colors, cyan, magenta and yellow, are controlled to be within the ranges specified by the invention.

Example 4

The.advantages of the present invention were confirmed visually on actual prints that were prepared from color negative films. The negatives had been obtained by shooting actual scenes (several objects having different degrees of lightness and color tone) on Sakura Color SR 100 with KONIKA FS-1, followed by a predetermined scheme of development and subsequent processing. The reproduction of neutral colors and chromatic colors on the prints was evaluated visually by the following criteria. The results are shown in Table 7.

Criteria for evaluation

In the above experiment, printing was conducted with Sakura Color Printer 5N-2 and development was performed with Process CPK-18 (a developer for color paper available from Konishiroku Photo Industry Co., Ltd.)
Table 7.shows the following: sample Nos. 25 to 27 prepared in accordance with the present invention achieved good reproduction of not only neutral colors but also monochromatic colors; and the advantages of the present invention could fully be confirmed by visual checking of prints prepared in the actual practice of color photography. It is therefore clear that a silver halide color photographic material prepared in accordance with the present invention produces color pictures that reproduce shaper monochromatic images and which have a good balance between neutral colors.

Example 5

Comparative sample Nos. 28 to 30 and sample Nos. 31 to 42 of the present invention were prepared as in Example 3 except that the cyan, magenta and yellow couplers were changed to those shown in Table 8. In all of these samples, the coating weight of silver (ie, silver deposit) was appropriately adjusted such that the ratios of y values would be within the ranges specified by the present invention.
The Y values of sample Nos. 28 to 42 were determined and their capability of color reproduction evaluated as in Example 3. The results are also shown in Table 8.
Comparative magehta coupler CM-2 listed in Table 8 had the following structure:
Table 8 shows that sample Nos. 31 to 42 prepared in accordance with the present.invention attained better color reproduction than comparative sample Nos. 28 to 30. Comparison between sample Nos. 39, 40, 41 and 42 shows that particularly good results are obtained by using a cyan coupler-of formula (IV) in combination with a cyan coupler of formula (III).

Example 6

Sample No. 43 was prepared by the same method as used for preparing sample No. 41 in Example 5, except that C-29 and C-36 were used as cyan couplers, compound No. 59 as a magenta coupler and Y-31 as a yellow coupler, and that the silver deposits for the respective emulsion layers were adjusted to attain ratios of y values that were within the ranges specified by the present invention.
Sample Nos. 44 and 45 were prepared by the same method as used for preparing sample No. 43, except that sample No. 44 used EMG-2 as the green-sensitive emulsion in the third layer while sample No. 45 used EMG-2 in the third layer. These two emulsions were the same as EMG-1 except that the amount of compound No. 13 of formula (V) that was added upon completion of chemical ripening was reduced to 0 mg and 10 mg, respectively, per mole of silver halide.
Sample No. 46 was prepared by the same method as used for preparing sample No. 46 except that compound No. 13 of formula (V) was incorporated in the fourth layer for a coating weight of 0.018 _mg/_m ².
Sample Nos. 47 and 48 were prepared by the same method as used for preparing sample No. 43 except that compound No. 4 of formula (VI) was changed to 0 mg/m and 0.₀2 g/_m ², respectively.
Sample No. 49 was prepared by the same method as used for preparing sample No. 43 except that compound No. 3 of formula (VII) was additionally incorporated in the third layer in an amount of 0.00₅ g/_m ².
The y values of sample Nos. 43 to 49 were determined and their capability of color reproduction evaluated as in Example 1. The ability of these samples to reproduce neutral colors was also evaluated as in Example 4. The results are shown in Table 9.
Table 9 shows that sample Nos. 45, 46, 48 and 49 exhibited even better. color reproduction because they employed the auxiliary technique of gradation adjustment described in this specification. However, sample Nos. 44 and 47 did not use any of the compounds of formulas (V), (VI) and (VII) and their ability to reproduce neutral colors in low-density areas was somewhat unsatisfactory although they were superior in respect of the area of color reproduction.
The seven samples were also subjected to evaluation of both resistance to fogging in an active color developing solution (ie, with reduced potassium bromide content) and stability of dye images under exposure to light (ie, exposure to sunshine for 30 days). Compared with sample No. 43, sample Nos. 44, 45 and 47 were slightly inferior in terms of resistance to fogging in the active developing solution, and sample No. 48 was somewhat unsatisfactory with respect to the storage stability of dye images under daylight. None of these problems occurred to either sample No. 46 or 49. These results show that if the technique of gradation adjustment described in this specification are used in an appropriate combination, gradation design can be achieved easily and improved color reproduction is attained; in addition, this enables the production of a silver halide color photographic material that is superior in the photographic characteristics other than other reproduction.

Claims

1. A silver halide color photographic material comprising a support;

a silver halide emulsion layer comprising a yellow-dye forming coupler of formula (I)

wherein _R1 is an alkyl or aryl group; _R2 is an aryl group; and Z₁ is hydrogen or a group that can be eliminated upon reaction with the oxidized product of a color developing agent;

a silver halide emulsion layer comprising a magenta-dye forming coupler of formula (II)

wherein Z is a chain of non-metallic atoms which, together with the nitrogen and carbon atoms to which it is attached, forms a nitrogen-containing heterocyclic ring which may optionally have at least one substituent; X is hydrogen or a group that can be eliminated upon reaction with the oxidized product of a color developing agent; and R is hydrogen or a substituent; and

a silver halide emulsion layer comprising a cyan-dye forming coupler of formula (III)

wherein R₂₁ is an alkyl or aryl group; R₂₂ is an alkyl, cycloalkyl, aryl or heterocyclic group; R₂₃ is hydrogen, halogen, an alkyl group or an alkoxy group, or R21 and R₂₂ form a ring together with the aryl ring and amide group to which they are attached; and Z₂ is hydrogen or a group that can be eliminated upon reaction with the oxidized product of a color developing agent;

the photographic material having a magenta γ to cyan γ ratio of 0.85:1 to 1.00:1 and a yellow γ to cyan γ ratio of 0.83:1 to 1.00:1 after it has been subject to monochromatic exposure to blue, green and red light under the conditions specified herein, and then developed and processed substantially under the conditions specified herein.

2. A silver halide color photographic material according to claim 1 wherein the magenta-dye forming coupler of formula (II) is one of the following:

wherein R₁ and X have the same meanings as R and X respectively as defined in claim 1 and each one of R₂ to R₈, together with their adjacent atoms, has the same meaning as Z as defined in claim 1.

3. A silver halide color photographic material according to claim 1 or 2 wherein the cyan-dye forming coupler of formula (III) has the formula (III)-1):

wherein R₂₄ is a phenyl group, R₂₅ is an alkyl or aryl group, R₂₆ is an alkylene group, X₁ is a divalent atom or group selected from -0-, -CO-, -COO-, -OCO-, -S0₂NR'-, -NR"SO₂NR"', -S-, -SO- and -SO₂- (wherein R', R" and R"' are each an alkyl group), n₁ is 0 or a positive integer, R₂₇ is hydrogen or a halogen, and Z₂ is as defined in claim 1.

4. A silver halide color photographic material according to claim 1 or 2 wherein the cyan-dye forming coupler of formula (III) has the formula (IV):

wherein R₂₈ is a straight-chained or branched alkyl group having from 1 to 4 carbon atoms, R₂₉ is a ballast group, and Z₂ is as defined in claim 1.

5. A silver halide color photographic material according to any one of claims 1 to 4 wherein Z₁, X and Z₂, which may be identical or different, are all groups that can be eliminated upon reaction with the oxidized product of a color developing agent.

6. A silver halide color photographic material according to any one of claims 1 to 5 wherein the silver halide emulsion layers containing the respective dye-forming couplers have the coating weights of silver and couplers specified as follows:

7. A silver halide color photographic material according to any one of claims 1 to 6 wherein at least one of the silver halide emulsions used in the silver halide emulsion layers containing the respective dye-forming couplers is a mixture of two or more emulsions having different sensitivities and/or levels of gradation.

8. A silver halide color photographic material according to any one of claims 1 to 7 which further comprises a compound of formula (V):

wherein Zo is a group of atoms which, together with the carbon and nitrogen atoms to which it is attached, forms a heterocyclic ring.

9. A silver halide color photographic material according to any one of claims 1 to 8 which further comprises a compound of formula (VI):

wherein R₃₁, R₃₂, R₃₃ and R₃₄, which may be identical or different, each signifies hydrogen, halogen, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, an alkylacylamino group, an arylacylamino group, an alkylcarbamoyl group, an arylcarbamoyl group, an alkylsulfonamido group, an arylsulfonamido group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a nitro group, a cyano group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylacyloxy group or an arylacyloxy group, provided that at least one of R₃₁, R_32' R₃₃ and R₃₄ is group having a total of at least 6 carbon atoms;
and/or a compound of formula (VII):

wherein R₄₁ is an alkyl group having from 1 to 5 carbon atoms, and R₄₂ is hydrogen or an alkyl group having from 1 to 5 carbon atoms.

10. A silver halide color photographic material according to any one of claims 1 to 9 wherein each of the silver halide emulsions used in the silver halide emulsion layers contains the respective dye-forming couplers in a mono-dispersed emulsion.