JPH02220044A - Silver halide color photographic sensitive material - Google Patents

Abstract

PURPOSE:To provide a silver halide color photographic sensitive material high in sensitivity and low in fog and not deteriorated in gradation against long time storage and fluctuation of processing conditions and suitable for color photography by forming core/shell type silver halide grain groups having layer structure different from each other in sensitivity and mixed with each other. CONSTITUTION:At least one of color sensitive layers contains the core/shell type silver halide grain groups having clear layer structure composed of the core high in silver iodide content and the shell surrounding the core low in the iodide content, and the groups contain silver halide grain groups different from each other in sensitivity in at least one of the color sensitive layers, and the groups may be formed different in sensitivity between two or more of the same color sensitive layers. The grains can be reduced in fluctuation coefficient and can obtain a wide exposure latitude by using silver halide grains containing a desensitizer.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a silver halide color photographic light-sensitive material suitable for full-color photography, and in particular to a negative-tone halogenated material using silver halide grains containing a desensitizer. This invention relates to silver color photographic materials.

[Background of the invention]

Nowadays, the so-called negative-positive method of color photography, in which images are taken with color negative film, enlarged onto color paper, and then color printed, is widely used.

This is because this color negative film has a very wide exposure latitude, so the probability of exposure failure during shooting is extremely low, and even some users without special knowledge can easily take color photos. It depends.

``Having a wide exposure latitude'' means that in a so-called characteristic curve in which the horizontal axis is the exposure amount and the vertical axis is the color density, it has a wide range of exposure latitude, from the shadow area where the exposure amount is low to the highlight area where the exposure amount is high. This means that the gradation is good over a wide exposure range, and if the gradation is poor, the color reproducibility and tone reproducibility of the dye image will deteriorate.

Color negative film, unlike color reversal film and color paper, is a photosensitive material that requires strict control of gradation over a wider exposure range than these, and for this reason, it is currently commercially available. The color negative film for photographic use has a layer sensitive to blue, green, and red light, a high-sensitivity layer containing silver halide grains with a large grain size, and a low-sensitivity layer containing silver halide grains with a small grain size. In addition, a so-called DIR compound is used which produces a development inhibitor as a result of reaction with an oxidized product of a developing agent.

By the way, the basic properties required of halogenated root particles are high sensitivity, low fog, and excellent granularity.In order to improve these basic properties,
Efforts have been made to precisely control the crystal habit, core/shell structure, or surface condition of silver halide.

JP-A-60-143331 discloses core/shell type silver halide grains with a clear layered structure in which a core with a high silver iodide content has a shell with a low silver iodide content, which improves sensitivity, fogging, and graininess. It is disclosed that photographic performance excellent in properties and the like can be obtained.

However, upon study by the present inventors, it was found that color negative films using the above silver halide grains have problems in storage stability over time and gradation stability against processing variations.

That is, as mentioned above, the above silver halide grains are used in a color negative film that has a multilayer structure using emulsion layers containing silver halide grains of different grain sizes, and further uses a DIR compound to strictly control the gradation. It has been found that, in the case where the film is stored over time or changes in processing conditions, the gradation deteriorates and the color reproducibility and tone reproducibility deteriorate. (The cause is not clear, but the halogenated root particles mentioned above cause this phenomenon.
This is thought to be because it has a clear layered structure including a core part of a high iodine layer and a shell part of a low iodine layer, and the developing activity is different between the low iodine part and the high iodine part.

Therefore, as a result of various studies in light of these problems, the present inventors have developed a core/shell type silver halide grain group having the above-mentioned clear layered structure, and silver halide grains having mutually different sensitivities. or a silver halide grain group formed by a mixture of two or more of the same color-sensitive layers, or a silver halide grain group having mutually different sensitivities between two or more of the same color-sensitive layers, and the silver halide grain group It has been found that the above-mentioned problems can be solved by containing a desensitizer in at least a part of the .

[Object and structure of the invention]

The present invention was invented based on the above knowledge, and has high sensitivity, low fog, and no deterioration of gradation due to changes in storage and processing conditions over time, that is, a wide exposure latitude, and a full-color single shadow The purpose of the present invention is to provide a silver halide color photographic light-sensitive material suitable for a support, in which one of a blue-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer and a red-sensitive silver halide emulsion layer is provided on a support.
In a silver halide color photographic light-sensitive material having at least one color-sensitive layer of 71 or more types, at least one of the color-sensitive layers includes a core having a high silver iodide content and a core having a high silver iodide content; The silver halide grain group contains a core/shell type silver halide grain group having a clear layered structure formed of a core and a shell with a low silver iodide content, and this silver halide grain group It is formed by the coexistence of halogenated root particles with mutually different sensitivities in at least one of the layers, or it is formed by the coexistence of halogenated root particles with mutually different sensitivities, or it is formed by mutual interaction between two or more of the same color-sensitive layers among the color-sensitive layers. A silver halide color photographic light-sensitive material, characterized in that silver halide grain groups having different sensitivities are formed in the silver halide grain group, and further, at least a part of the silver halide grain group contains a desensitizer. ,
This is related to.

[Detailed description of the invention]

The term "silver halide grains having a clear layered structure" in the present invention can be clarified by the X-ray diffraction method described below.

An example of applying the X-ray diffraction method to silver halide grains is described, for example, in H. Hirsch, "Journal of Photographic Science", Vol. 10 (1962), pp. 129 et seq. The method is based on Black's condition (2dsi
This method utilizes the fact that a diffraction peak occurs at a diffraction angle that satisfies nθ=nλ).

The standard measurement method uses Cu as the target,
Using alpha rays as a radiation source for Cu, tube voltage 4゜KV, tube current 1
At 00 mA, silver halide (
There is a method of measuring the diffraction pattern of a 420) surface and obtaining a curve of diffraction intensity versus diffraction angle.

According to this method, a silver halide grain having two distinct layered structures means that a maximum diffraction peak due to silver halide in a high iodide portion and a low iodide portion occur.

Further, it is preferable that the diffraction peak intensity corresponding to the high iodine portion inside the grain is 1/20 to 1/1, more preferably 1/20 to 1/1 of the diffraction peak intensity corresponding to the low iodine portion outside the grain. l O ~ 1/1.

In the present invention, the emulsion having substantially two distinct layered structures has a diffraction intensity of 2 at the minimum value between the two peaks.
90 of the weakest diffraction maxima (peaks)
% or less.

Even in the case of an emulsion in which many types of grains with different halogen compositions coexist, each consisting of a uniform phase, substantially two peaks may appear in the X-ray diffraction. It is not possible to develop the excellent photographic performance obtained with .

Although the silver halide emulsion is Milk 7FI according to the present invention,
Alternatively, in addition to the X-ray diffraction method, EPMA method (E
electron-probe MiCr.

This can be determined by using the Analyzer method).

In this method, a well-dispersed sample is prepared so that the emulsion grains do not come into contact with each other, and elemental analysis of minute portions can be performed by X-ray analysis using electron beam excitation by irradiating the sample with an electron beam.

According to this method, the halogen composition of each particle can be determined by determining the characteristic X-ray intensities of silver and ghost emitted from each particle.

By confirming the halogen composition of at least 50 grains by the EPMA method, it can be determined whether the emulsion is an emulsion according to the present invention.

In the emulsion according to the present invention, it is preferable that the content of speckles between grains is more uniform. When the distribution of iodine content between particles is measured by the EMPA method, the relative standard deviation is preferably 50% or less, more preferably 35% or less, and particularly preferably 20% or less.

In the silver halide grains according to the present invention, the silver iodide content in the internal (core) high-magnitude region is preferably 10 mol%.
or more, more preferably 10 to 45 mol%,
Particularly preferably 15 to 40 mol%. The silver iodide content in the low iodine region of the shell is preferably 0 to 7.
It is mol%, more preferably 0 to 5 mol%. That is, when the silver iodide content is 0, it means that it is silver bromide.

The emulsion of the present invention is an emulsion mainly containing silver iodobromide, but it may contain silver halide of other compositions, such as silver chloride, as long as the effects of the present invention are not impaired.

The average silver iodide content of the silver halide emulsion of the present invention is:
Preferably it is 2 to 30 mol%.

The silver halide emulsion according to the present invention can be prepared by appropriately selecting and combining various manufacturing methods known to those skilled in the art.

That is, methods such as acid method, neutral method, ammonia method,
Further, the method for reacting the soluble root salt and the soluble halogen salt can be selected from a one-sided mixing method, a simultaneous mixing method, or a combination thereof.

As one type of simultaneous mixing method, a method in which pA and g in a liquid phase in which silver halide is produced can be kept constant, that is, a controlled double jet method can also be used. As another type of simultaneous mixing method, a triple jet method in which soluble halogen salts of different compositions are added independently (for example, soluble root salt, soluble bromine salt, and soluble iodide salt) can also be used.

Silver halide solvents such as ammonia, rhodan salts, thioureas, thioethers, and amines may be used during core preparation.

Preferred preparation methods include the following.

That is, in the preparation process, silver halide fine particles having a solubility product equal to or less than the minimum solubility product among the solubility products of each silver halide of the emulsion mixed crystal components constituting the silver halide emulsion are used to form the liquid crystal. The emulsion is prepared by allowing the presence of the silver halide-forming element until the end of supply of the silver halide-forming element.

To give a specific example, in the preparation of silver iodobromide grains having a clear layered structure, part or all of the conventionally used potassium iodide aqueous solution is supplied using Agl fine grains.

The particle size of the Agl fine particles is preferably 0.7 μm or less, more preferably 0.3 to 0.005 μm, particularly preferably 0.7 to 0.01t! It is m.

In the silver halide preparation step, the temperature of the reaction mother liquor is 10 to 70"C, preferably 20 to 60"C, pAg
is 6-11, preferably 745-1O55, and pH is 5-11.
11, preferably 7-10.

When preparing a silver halide emulsion (including when preparing a seed emulsion), a substance other than gelatin that exhibits adsorption properties to silver halide grains may be added. Such adsorbing substances are useful, for example, compounds or heavy metal ions used in the art as sensitizing dyes, antifoggants or stabilizers. The above-mentioned adsorptive substances are specifically described in JP-A-62-7040.

Among the adsorbent substances, it is preferable to add at least one of an antifoggant and a stabilizer during the preparation of the silver halide seed emulsion in order to reduce fog and improve stability over time of the emulsion.

Among the antifoggants and stabilizers mentioned above, heterocycles are preferred. Specific examples of more preferred heterocyclic mercapto compounds and azaindene compounds are described in detail in JP-A-61-185917, and these can be used.

The amount of the above-mentioned heterocyclic mercapto compound and azaindene compound added is not limited, but is preferably 1X10"' to 3 x 104 mol, more preferably 5X10-' to 3 x 1O-3 mol per mol of silver halide. This amount is appropriately selected depending on the manufacturing conditions of the silver halide grains, the average grain size of the silver halide grains, and the type of the above-mentioned compound.

A4 for finished emulsions that have the specified grain conditions.
After the X particles are formed, they are desalted by a known method. As a method for desalting, an agglomerated gelatin agent used for desalting AgX particles as seed particles may be used, or a tardel water washing method in which gelatin is gelatinized may be used.
Furthermore, inorganic salts consisting of polyvalent anions, such as sodium sulfate, anionic surfactants, anionic polymers (
For example, a coagulation method using polystyrene sulfonic acid (polystyrene sulfonic acid) may be used.

The silver halide grains thus desalted are redispersed in gelatin to prepare a silver halide agent.

The silver halide grains according to the present invention are cubic, tetradecahedral,
It may be a normal crystal such as an octahedron, it may be composed of twins, or a mixture thereof, but a normal crystal is preferable.

The average particle size of the halogenated root particles according to the present invention is not particularly limited and may be changed depending on the application, but is preferably 0.
．． It is 1 μm to 3.0 μm. In the case of cubic silver halide grains, the average grain size here refers to the length of its side, and in the case of shapes other than cubes, the average grain size refers to the length of one side when converted to a cube having the same volume. The individual particle size in this sense is rt, and when the total number of measured particles is n, it is expressed as Σri average particle size r=.

Further, the silver halide emulsion according to the present invention is preferably monodisperse.

Monodisperse silver halide grains are those in which most of the silver halide grains have the same shape and uniform grain size when observed with an electron microscope.

For monodisperse silver halide grains, the value obtained by dividing the standard deviation of the grain size distribution by the average grain size (coefficient of variation) is preferably 0.20.
It is as follows.

The emulsion according to the present invention is chemically sensitized by conventional methods. In other words, compounds containing sulfur that can react with silver ions,
A sulfur sensitization method using activated gelatin, a selenium sensitization method using a selenium compound, a reduction sensitization method using a reducing substance, a noble metal sensitization method using gold or other noble metal compounds, etc. can be used alone or in combination. .

In the present invention, at least one color-sensitive layer includes a silver halide grain group containing silver halide grains having mutually different sensitivities; The grain groups may be present separately in two or more silver halide emulsion layers having the same color sensitivity (for example, a high-speed emulsion layer and a low-speed emulsion layer), or may be present in one or more silver halide emulsion layers. Silver halide grains having mutually different sensitivities may be present in a mixed state in two or more silver halide emulsion layers. The desensitizer may be present in any of the silver halide grains of the above silver halide grain group, but it is preferably present in low-sensitivity silver halide grains.

Usually, in color negative films, in order to obtain a wide exposure latitude, the same color-sensitive layer is composed of a high-speed emulsion layer containing silver halide grains with large grain sizes and a low-sensitivity emulsion layer containing grains with small grain sizes. By making a desensitizer exist in low-sensitivity silver halide grains, the grain size can be increased (i.e., close to the grain size of high-speed grains) while keeping the sensitivity of the low-speed grains low. Furthermore, it is possible to make the particle size the same as that of the high-sensitivity particles.

Also, when high-sensitivity grains and low-sensitivity grains are mixed in the same emulsion layer and the same color-sensitive layer is configured as a single layer,
It is advantageous for -C to have small differences in particle size.

The fact that the color-sensitive layer is a single layer means that the emulsion layer contains a plurality of layers having the same type of coupler, grain size of silver halide grains, halogen composition and crystal habit, and the same ratio of coupler and silver halide. It also includes the case where emulsion layers of the same color sensitivity are arranged as a continuous layer.

Here, "having the same color sensitivity" or "same color sensitivity" means, for example, having the same blue sensitivity, green sensitivity, and red sensitivity, and not necessarily having exactly the same spectral sensitivity characteristics. It doesn't mean something.

In the present invention, it is preferable that the blue-sensitive layer is a single layer, and it is more preferable that both the blue-sensitive and green-sensitive silver halide emulsion layers are a single layer, and in particular, the blue-sensitive, green-sensitive and red-sensitive halogen It is preferable that all of the silver oxide emulsion layers are a single layer.

When the same color-sensitive layer has a single-layer structure, the number of coated layers of photosensitive material is reduced compared to the conventional multi-layer structure, and the film can be made thinner. Therefore, in such a case,
Production efficiency, sharpness is improved, and graininess is also improved. The film thickness after drying is preferably 20 to 3 μm, particularly preferably 15 to 5 μm.

Exposure latitude is the width of the light receiving area where a significantly different exposure effect appears, and is the exposure range from the highlight part to the deep shadow part in the characteristic curve, and is
93 (Shashin Kogyo Publishing, 1982).

That is, it is the difference in logH at two points where the slope of the tangent line at the foot and shoulder of a characteristic curve in which the horizontal axis is logH and the vertical axis is transmission density is 0 and 2, respectively.

The photosensitive material of the present invention preferably has an exposure latitude of 3.0 or more, preferably 3.0 to 3.0, as measured by the above method.
8.0 is particularly preferred.

In the present invention, by using silver halide grains containing a desensitizer, a wide exposure latitude can be obtained even if the coefficient of variation of the entire grain is made small.

Therefore, these silver halide grains with a small coefficient of variation that are exposed to the same environment are preferable because their photographic performance is stabilized against changes over time and fluctuations in development processing. It is also possible to chemically sensitize a mixed system of silver particles in the same batch.

Various desensitizers can be used, such as metal ions, antifoggants, stabilizers, and desensitizing dyes.

In the present invention, metal ion doping is particularly preferred. The metal ions used for this doping include group 1b and u group in the element synchronization line table.
Mention may be made of metal ions of group B, group 1[Ia, group mb, group 1Vb, group Va and group 1]. Preferred metal ions include Au, ZnSCd, Tll, Sc, Y
, B l, Fe, Ru.

Mention may be made of the metal ions 0sSRh, , lr, Pd, Pr, Sm and Yb, especially Rh, Ru, Os and Ir.
These metal ions can be used, for example, as halogen complex salts, and can be used as Ag during doping.
The pH of the X suspension system is preferably 5 or less.

The doping amount of these metal ions depends on the type of metal ion,
It varies depending on the grain size of silver halide grains, the doping position of metal ions, the desired sensitivity, etc., but it is preferably 10-17 to 10-mol per 1 mol of AgX, and
Q-I is preferably 11 to 10-3 mol, especially 10-9 to
10-4 mol is preferred.

A variety of different sensitivity qualities can be imparted to the silver particles.

If the doping amount is less than 10-2 mol/A g It is also possible to mix these in a predetermined ratio and prepare them in the same batch for chemical sensitization. Each silver halide grain receives an aggravating effect based on its properties, and an emulsion having a wide exposure latitude can be obtained depending on the sensitivity difference and mixture ratio.

As the antifogging agent or stabilizer, azoles (
(e.g., benzthiazolium salts), indazoles, triazoles, benztriazoles, benzimidazoles, etc.), heterocyclic mercapto compounds (e.g., mercaptotetrazoles, mercaptothiazoles, mercaptothiazoles, mercaptobenzthiazoles, mercaptobenzimidazole) mercaptopyrimidines, etc.), azaindenes (e.g., tetraazaindenes, pentaazaindenes, etc.), nucleic acid decomposition products (e.g., adenine, guanine, etc.), benzenethiosulfonic acids, thioketo compounds, etc.

Desensitizing dyes include cyanine dyes, merocyanine dyes,
Examples include complex cyanine dyes, complex merocyanine dyes, holoporacyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes.

The location of the desensitizer is preferably mixed inside the silver halide grains from the viewpoint of storage stability of the photosensitive material and stagnation stability of the coating solution, and its distribution is uniform. The particles may be unevenly distributed at the center of the particle or at an intermediate position, or may gradually decrease from the center of the particle toward the outside.

From the viewpoint of production efficiency, it is preferable that the particles are unevenly distributed in the center of the particles, and if a method using seed particles with a small coefficient of variation is adopted, the steps after particle growth can be performed in the same batch.

The silver halide grain group of the present invention includes grains having different sensitivities, and the difference in sensitivity between the silver halide grains with the highest sensitivity and the silver halide grains with the lowest sensitivity, that is, Δ1. ．． o
It is preferable that the sensitivity difference is such that g H is 0.1 or more.

In the light-sensitive material of the present invention, at least one color-sensitive layer (for example, a blue-sensitive layer) contains desensitizer-containing AgX particles, preferably a blue-sensitive layer, more preferably a blue-sensitive layer. and the green-sensitive layer, most preferably all the color-sensitive layers, contain desensitizer-containing AgX particles.

The silver halide grains contained in each silver halide emulsion layer as a whole are defined by the ratio S/r of the standard deviation of grain size (S) and the average grain size (7), each defined by the following formula: It is preferable that the coefficient of variation is 0.4 or less, and 0.33
The following is more preferable, 0.25 or less is even more preferable, 0
．． 20 or less is particularly preferred.

When the number of particles of ri (length of one side when converted to a cube) is ni, it is defined by the following formula.

The relationship between Σn1-ri particle size distribution is described by Tribel and Smith in "Empirical Relationship between Sensitometric Distribution and Particle Size Distribution in Photography," The Photographic Journal, Vol. LXXIX (1949), pp. 330-338. It can be determined using the method described in the paper.

Antifoggants, stabilizers, etc. can be added to the silver halide emulsion. Gelatin is advantageously used as binder for the emulsion.

The average grain size (r) refers to the grain size (in the case of cubic silver halide grains, the length of its side, and in the case of grains with shapes other than cubes, the dispersion of soluble synthetic polymer having the same volume) (latex).

A coupler is used in the emulsion layer of a color photographic light-sensitive material, and furthermore, by coupling with a colored coupler that has a color correction effect, a competing coupler, and an oxidized form of a developing agent, a developer, a silver halide solvent, and a toning agent are used. Compounds that release photographically useful fragments such as agents, hardeners, antifoggants, chemical enhancers, spectral sensitizers or desensitizers can be used.

The photosensitive material may be provided with auxiliary layers such as a filter layer, an antihalation layer, and an antiirradiation layer. These layers and/or the emulsion layers may contain dyes that are leached from the light-sensitive material or bleached during the development process.

A formalin scavenger-1 fluorescent brightener, a matting agent, a lubricant, an image stabilizer, a surfactant, an anti-color cast agent, a development accelerator, a development retardant, a bleach accelerator, etc. can be added to the photosensitive material.

As a support, paper laminated with polyethylene, etc.
Polyethylene terephthalate film, baryta paper, cellulose triacetate, etc. can be used.

The photosensitive material of the present invention is particularly useful as a negative photosensitive material.

To obtain a dye image using the light-sensitive material of the present invention, conventionally known color photographic processing can be used after exposure.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Prior to Examples 1 and 2 below, silver halide emulsions used in those Examples were first prepared.

11. Add the silver nitrate aqueous solution, potassium iodide aqueous solution, and potassium bromide aqueous solution to the reaction vessel containing the gelatin aqueous solution while controlling the PAg and pH in the reaction vessel and controlling the addition time of each of the silver nitrate aqueous solution, potassium iodide aqueous solution, and potassium bromide aqueous solution. After simultaneously adding an aqueous solution of
Next, gelatin was added to prepare seed emulsion NE-1.

Next, seed emulsion NE-2 was prepared in the same manner as above except that K and RhC1 were added to the reaction vessel. J1
Manufactured.

These seed emulsions are shown in Table 1.

Next, an ammoniacal silver nitrate aqueous solution, a potassium iodide aqueous solution, and a potassium bromide aqueous solution were added to the reaction vessel containing the above seed emulsion and gelatin aqueous solution while controlling the PAg and pH in the reaction vessel. and at appropriate particle size, add gelatin to the potassium bromide solution and redisperse.
An emulsion was obtained with an A g of 7.8 and a pH of 6.0.

In the manner described above, silver iodobromide emulsions EM-1 to EM-3 having a high yoma content inside silver halide grains were prepared.

Then, an emulsion containing core/shell type halogenated root particles having a distinct layered structure was prepared as follows.

58 g of ossein gelatin at a temperature of 40"C.

Aqueous solution 121 containing 2.1 g of 4-hydroxy-6-methyl-1,3,3a,7-titrazaindene (hereinafter abbreviated as TAI) and 0.068 m oε (in terms of silver) of the above seed emulsion
3.5N ammoniacal silver nitrate aqueous solution 2977m&-5 and TA I 1.7
2977 ml of 3.5N aqueous potassium bromide solution containing g
, f) Ag 8.55-10.20, p++ 9.0
It was added over 14 minutes by the double jet method while controlling the temperature at ~n, o, °. In addition, at the same time as adding the silver nitrate aqueous solution, an average particle size of 0.05 II was separately added for adjustment.
m iodized root particles 0.084 mon (silver equivalent) 9.5
Added in minutes. After silver halide grains are formed in this way, they are desalted, gelatin is added and fractionated again, and the pA
Emulsion EM-4 with g 7.8 and pH (6,0)
EM-6 was obtained. As a result of electron microscopic observation, the emulsion thus obtained was found to be a monodisperse emulsion with an average grain size of 0.5 μm and a coefficient of variation of 0.19.

In addition, with reference to the above production example, the average particle size is 0.20 μm,
Emulsion EM-7 was produced with a coefficient of variation of 0.20.

The emulsions prepared as described above are summarized in Table 2.

*1: Structural analysis of EM-1-EM-6 was performed using X-ray diffraction method to determine whether they have a clear layered structure.
Line diffraction is classified into two peaks (some have a layered structure) and others where only one peak appears because the peaks are not separated (some have a clear layered structure). It was displayed.

*2: Used by mixing NE-1 and NE-2 in an equimolar ratio.

Example 1 The above Em-1=Em-7 was optimally sensitized using sodium thiosulfate, chloroauric acid, and sensitizing dyes (1) and (2). Ag
7 moles of magenta coupler CM-1) per mole of X, 0
．． 7 moles of colored magenta coupler (CM-1) and 0.5 moles of DIR compound (D-1) are simultaneously di-
The solution dissolved in t-nonyl phthalate was dispersed in an aqueous gelatin solution, and the resulting solution was added to the emulsion shown in Table 2 to prepare a coating solution.

Next, the above coating solution was applied onto the subbed cellulose acetate support at a coating amount of 1.50 g/m'' as metallic silver.
, a yellow filter layer containing 0.15 g/m'' sensitizing dye ■ luterephthalate dispersion and gelatin of 1.5 g/m'' It was applied.
For each layer above, add 1g of gelatin (hardening agent) 1-1 to each layer.
30 mg was added per portion.

Each sample was subjected to wedge exposure and processed in the following processing steps according to a conventional method.

Sensitizing dye IM-1 S-1 0! I υ■ Processing process (38°C) Processing development 3 minutes 15 seconds bleaching
Washing with water for 6 minutes and 30 seconds Fixing with water for 3 minutes and 15 seconds Washing with water for 6 minutes and 15 seconds Stabilizing for 3 minutes and 15 seconds Drying for 1 minute and 30 seconds The composition of the processing solution used in each processing step is shown below.

Saragori Eiyu 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl) aniline sulfate 4.75 g Anhydrous sodium sulfite 4.25 g Hydroxylamine 1/2 sulfate 2.0 g Anhydrous Potassium carbonate 37.5 g Potassium bromide
1.3g nitrilotriacetic acid 3
Sodium salt (L aqueous salt) 2.5 g Potassium hydroxide E, Og Add water to adjust to 1β (pH -10°02) Iron(II) ethylenediaminetetraacetate Ammonium salt 100.0g Ethylenediaminetetraacetic acid diammonium Salt 10.0 g Ammonium bromide 150゜0 g Glacial acetic acid
Add 10.0 g of water to make 1ffi, and adjust the pH to 6.0 using aqueous ammonia.

Main jar ammonium thiosulfate 175.0 g
Anhydrous ammonium sulfite 8.6g Sodium metasulfite 2.3g Add water to make 11, and adjust to pH 6.0 using acetic acid.

Stable formalin (37% aqueous solution) 1°5d Konidax (Konica Co., Ltd.) Add 7.5d water to make iz.

Each sample thus obtained was divided into two parts, one of which was stored refrigerated (5°C), while the other was stored at 40°C under forced aging conditions of 50% relative humidity for 14 days, and then the above After performing wedge exposure in the same manner, the sample was processed through the processing steps described above, and the gradation preservation property (described later) during storage of the sample over time was evaluated. In addition, after dividing the sample into two and applying wedge exposure in the same manner as above, the sample was processed in the same manner as above except that the p)I of the color developing solution in the processing step was changed to 9.8. The gradation preservation was evaluated.

The above method for evaluating gradation preservation will be explained with reference to the accompanying drawings.

Figure 1 shows the standard characteristics! tfA (broken line) and the characteristic curve to be evaluated (solid line) are shown. Δf;! from the exposure point giving the minimum density +2.1 density in FIG. ,ogH
Each exposure point between the exposure points of = +3.0 (Δf between each exposure point
FIG. 2 shows the point gamma value of fogl-1=o, 15). From FIG. 2, the absolute value Δγ of the difference in point gamma at each exposure point between the reference characteristic curve and the characteristic curve to be evaluated is determined. That is, the larger the value of Δγ, the larger the difference in point gamma between the two characteristic curves, and the larger the value of Σ, the more uneven the change in gradation becomes, resulting in worse gradation preservation.

Table 3 shows the relative sensitivity, the results of the tone preservation during storage over time evaluated as described above, the tone preservation under variations in processing conditions, and the sample contents. Note that the relative sensitivity is the reciprocal of the exposure amount that gives a density of fog density + 0.3, and is expressed as a relative value when comparative sample 1 is taken as 100.

As is clear from Table 3, compared to comparative samples 1 to 3,
Samples 1 and 2 of the present invention have high sensitivity, have small gradation changes from the highlight part to the shadow part of the characteristic curve due to storage and processing variations over time, and have excellent tone reproducibility. I understand that. Examining this result in detail, Comparative Sample 3 is a core/shell type emulsion with a clear layered structure containing silver halide grains with different grain sizes.
is satisfactory in terms of sensitivity, but the deterioration of gradation due to storage over time and processing variations is significant. In contrast, Samples 1 and 2 of the present invention, which used emulsions with a clear layered structure and in which the grains were doped with Rh ions to vary the sensitivity of the silver halide grains, not only had sufficiently satisfactory sensitivity, but also , gradation preservation is significantly improved. This improvement effect was unexpectedly greater than the effect of an emulsion without a clear layered structure (comparison of Comparative Samples 1 and 2). From the results of Comparative Samples 1 to 3 and Inventive Sample I, excluding the emulsions containing silver halide grains with small grain sizes and the emulsions doped with Rh ions, the exposure latitude of the samples in which equimolar amounts were replaced with the remaining emulsions was approximately 2.6, which has a serious drawback of narrow exposure latitude.

In addition, since the emulsion contained in Invention Sample 2 does not contain two types of emulsions, physical ripening (grain formation) and chemical sensitization are performed in one step each during emulsion production. , production efficiency is high and preferred.

Example 2 Comparative sample 4 of a multilayer color light-sensitive material having a multilayer structure having the composition shown below was prepared on a subbed cellulose acetate support.

For silver halides and colloidal silver, the coating amount is approximately 3 g/% in terms of silver.
．． 3, and the wide exposure latitude is expressed in moles per mole of silver halide in the same layer for DIR compounds. The emulsions contained in each color-sensitive emulsion layer were optimally sensitized using sodium thiosulfate and chloroauric acid.

Sensitizing dye■ Sensitizing dye■ Sensitizing dye■ V-1 Cal1w(t) V-2 C! II S CC-1 D-2 S-1 (blank below) Hereinafter, each layer with the above composition is HC, rL-1, R-
1,,R-2,IL,-2,G-ISO-2,YC,B
-1, B-2, Pro-1 and Pro 2.

Next, Comparative Sample 5 and Invention Samples 3 to 8 were produced.

Comparative sample 5 and inventive sample 3 are B-1 of comparative sample 4.
Comparative Sample 4 was prepared in the same manner as Comparative Sample 4, except that the emulsions contained in , G-1, and R-1 were replaced with those shown in Table 4.

Sample 4 of the present invention is G
The emulsion contained in G-1 was replaced with an equimolar mixture of EM-4 and EM-5, and the emulsion contained in G-1, gelatin and T
It was produced in the same manner as Comparative Sample 4 except that the amount of CP used was increased by 30%.

The amounts of the sensitizing dye, coupler, and DIR compound of G-1 per mole of silver halide were the same as those of Comparative Sample 4.

The present invention sample 5 is the present invention sample 4 except for B-2,
Sample 4 of the present invention except that the emulsion contained in B-1 was replaced with an equimolar mixture of EM-4 and EM=5, and the amounts of emulsion, gelatin, and TOP contained in B-1 were increased by 15%. It was produced in the same manner as.

The amounts of the sensitizing dye and coupler added per mole of silver halide in B-1 are the same as those of sample 4 of the present invention, and R
The amounts of the sensitizing dye, coupler and DIR compound added per mole of silver halide in Sample-1 were the same as Sample 5 of the present invention.

The present invention sample 6 is the present invention sample 5 except for R-2,
Samples of the present invention except that the emulsion contained in R-1 was replaced with an equimolar mixture of EM-1 and EM-2, and the amounts of emulsion, gelatin, and DOP contained in R-1 were increased by 25%. It was produced in the same manner as 5.

Sample 7 of the present invention contains the emulsion contained in Sample 6 of the present invention by EM-
Sample 6 was prepared in the same manner as Sample 6 of the present invention except that Sample 6 was replaced with Sample 6.

Table 4 shows each sample prepared in this way and its contents.

Comparative Samples 4 to 5 and Invention Samples 3 to 7 thus obtained were subjected to wedge exposure in the same manner as in Example 1, and then processed.

Then, in the same manner as in Example 1, the gradation preservation properties during storage over time and gradation preservation properties under processing variations were evaluated.

Table 5 shows the results obtained in the green sensitive layer.

(Leaving space below) 'tt;, + t<: Wakumago Pugo 1f Town 1υmouth 1 Sensitivity: Reciprocal of the exposure amount that gives a density of fog +0.3, when the value of comparative sample 4 is taken as 100 Expressed as a relative value.

Table 5 shows that, similar to Example 1, the sample of the present invention has higher sensitivity than the comparative sample, and is resistant to storage and processing variations over time, with a gradation level from the highlight to the shadow of the characteristic curve. It can be seen that the displacement is small (and the tone reproducibility is excellent).

Comparing the samples of the present invention, sample 4 of the present invention, which has a single color-sensitive layer, is preferable because it has higher sensitivity (and has a greater effect of improving gradation storage stability), and has a higher blue sensitivity. Sample 5 of the present invention, which has a single configuration of the layer and the green-sensitive layer, is more preferable from the above points, and Samples 6 and 7 of the present invention, which have a single panchromatic layer, have a particularly large improvement effect ( , it turns out that it is even more preferable.

The exposure latitude of all samples was approximately 3.8 expressed as ΔfogH, indicating that they had a sufficiently wide exposure latitude.

Furthermore, the present invention also applies to samples using emulsions doped with Rh ions contained in EM-5 in place of Ru ions, Os ions, and Pd ions, respectively, instead of EM-5 contained in Samples 3 to 6 of the present invention. The intended effect was obtained. In addition, Rh contained in EM-7 used in sample 7 of the present invention
The effects intended by the present invention were also obtained with samples using emulsions doped with each of the above metal ions instead of ions.

〔Effect of the invention〕

As is clear from the above description, according to the present invention,
1. High sensitivity, low fog, and no deterioration of gradation due to storage over time or processing variations, that is, wide exposure latitude. A silver halide color photographic material suitable for full-color photography is provided.

[Brief explanation of the drawing]

Figure 1 shows the characteristic curves of the standard (dashed line) and evaluation target (solid line) photographic materials, and Figure 2 shows the point gamma of the standard (dashed line) and evaluation target (solid line) photographic materials. FIG. Applicant Konica Co., Ltd. Agent Patent Attorney Miki Nakajima Yugai (1 person)

Claims (1)

[Claims] One of a blue-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer and a red-sensitive silver halide emulsion layer on a support.
In a silver halide color photographic light-sensitive material having at least one color-sensitive layer of a seed or two or more types, at least one of the color-sensitive layers includes a core having a high silver iodide content and a core having a high silver iodide content. This silver halide grain group contains a core/shell type silver halide grain group having a clear layered structure formed from a surrounding shell with a low silver iodide content, and this silver halide grain group is one of the color-sensitive layers. It is formed by a mixture of silver halide grains having mutually different sensitivities in at least one layer of the color-sensitive layer, or two of the color-sensitive layers
A silver halide grain group having mutually different sensitivities is formed between the same color-sensitive layers, and further, at least a part of the silver halide grain group contains a desensitizer. A silver halide color photographic light-sensitive material.