JP2000089403A - Silver halide emulsion and silver halide color photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide, first, a silver halide emulsion having improved sensitivity, graininess, pressure characteristics as well as preservability of latent image and reciprocity law failure characteristics, and to provide, secondary, a silver halide color photographic sensitive material showing further improved stability against changes in a developing process by using the silver halide emulsion having improved characteristics above described. SOLUTION: This emulsion contains silver halide particles and a dispersion medium, in which the coefft. of variation in the particle size of the whole silver halide particles included in the emulsion is <=25%. In the whole projected area of silver halide particles, >=50% of the area is produced by planer particles having >=5 aspect ratio. The planer particles contain at least one kind of polyvalent metal compd. in the peripheral part of the particle, and >=30% of the planer particles (in number) have dislocation lines in the center region and peripheral region of the principal plane. The dislocation lines in the peripheral region are present by >=20 lines per one particle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a silver halide emulsion useful in the field of photography and a silver halide color photographic light-sensitive material using the same. More specifically, the present invention relates to a silver halide color photographic light-sensitive material having high sensitivity, excellent graininess, and remarkably improved stability against development processing fluctuations in addition to reciprocity failure characteristics and pressure characteristics.

[0002]

2. Description of the Related Art In recent years, compact cameras and auto-focus cameras 1
With the spread of eye reflex cameras and films with lenses, there has been a strong demand for the development of silver halide color photographic materials having high sensitivity and excellent image quality. Therefore, demands for improved performance of photographic silver halide emulsions are becoming more severe, and higher levels of demands are made on photographic performance such as high sensitivity, excellent graininess, and excellent sharpness.

In response to such demands, for example, US Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, and 4,414, Nos. 306 and 4,459,353 disclose techniques using tabular silver halide grains (hereinafter also simply referred to as "tabular grains"). There are known advantages such as improvement in sensitivity, improvement in sensitivity / granularity, improvement in sharpness due to specific optical properties of tabular grains, and improvement in covering power. However, it is not enough to meet recent high-level demands, and further improvement in performance is desired.

[0004] In connection with the trend toward higher sensitivity and higher image quality, demands for improvement in pressure characteristics of silver halide photographic materials have been increasing more than ever. Although it has been considered to improve the pressure characteristics by various means, a technique for improving the stress resistance of silver halide grains itself is better than a technique using an additive such as adding a plasticizer. The view that it is practically preferable and that the effect is large is promising. In response to these demands, emulsions comprising core / shell type silver halide grains having a silver iodobromide layer having a high silver iodide content have been actively studied. In particular, silver iodobromide emulsions containing core / shell grains having a high silver iodide phase content of 10 mol% or more inside grains have attracted much attention as, for example, emulsions for color negative films.

As a method for increasing the sensitivity of a silver halide emulsion, a technique of introducing dislocation lines into tabular silver halide grains is disclosed in US Pat. No. 4,956,269. It is generally known that when pressure is applied to silver halide grains, fogging or desensitization occurs.However, grains having dislocation lines introduced therein have a problem that they are significantly desensitized by application of pressure. Was. JP-A-3-189642 discloses that tabular silver halide grains having an aspect ratio of 2 or more and having 10 or more dislocation lines in a fringe portion, and the size distribution of the tabular silver halide grains are simple. Dispersed silver halide emulsions are disclosed. However, this technique does not improve the significant desensitization caused by the pressure caused by introducing dislocation lines.

Techniques for improving pressure characteristics with core / shell type particles include, for example, JP-A-59-99433 and JP-A-59-99433.
The techniques disclosed in Japanese Patent Nos. 0-35726 and 60-147727 are known. Also, JP-A-63-220238,
Also, Japanese Patent Application Laid-Open No. Hei 1-2201649 discloses a technique for improving sensitivity, graininess, pressure characteristics, exposure intensity dependency, and the like by introducing dislocations into silver halide grains. Japanese Patent Application Laid-Open No. 6-235988 discloses a technique of improving pressure resistance by using monodisperse tabular grains of a multi-structure type having a high iodine layer in an intermediate shell.

However, these techniques have not been satisfactory as silver halide emulsions having high sensitivity, excellent graininess, and markedly improved pressure characteristics, which can withstand recent high-level requirements.

[0008] As an improved technique for such a demand,
Japanese Patent Application No. 9-280459 discloses a tabular silver halide emulsion having dislocation lines in a main plane and a fringe portion.

According to the technique disclosed in the present invention, the sensitivity, graininess, and pressure characteristics, which are the basic characteristics of the silver halide emulsion, have been remarkably improved.

However, it cannot be said that the recent improvement in characteristics required for a silver halide color negative photographic light-sensitive material is insufficient with only the above three basic characteristics.

In particular, it is said that stability against fluctuations in the use conditions of the user and the processing conditions in the laboratory is a condition of an excellent silver halide color negative photographic material. That is, it is necessary to further improve the stability of use conditions typified by latent image storability, reciprocity failure characteristics, and the stability of process conditions typified by development process fluctuation stability.

The present inventors have found that tabular silver halide emulsions having dislocation lines in the main plane and the fringe portion have excellent sensitivity,
Focusing on the granularity and pressure characteristics, while continuing research on functional improvement to further improve the characteristics dramatically and synergistically, besides those characteristics, the latent image preservability, reciprocity failure characteristics, development which has further increased in recent years The tabular silver halide emulsion was found to be very useful for improving characteristics such as processing fluctuation stability.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a silver halide emulsion in which, in addition to sensitivity, graininess and pressure characteristics, latent image preservability and reciprocity failure characteristics are remarkably improved. The second object is to provide a silver halide color photographic light-sensitive material having improved stability in fluctuations in the development process by using a silver halide emulsion whose properties have been improved.

[0014]

SUMMARY OF THE INVENTION The object of the present invention is to provide a silver halide particle and a dispersion medium, wherein all silver halide particles contained have a coefficient of variation of 25% or less,
50% or more of the total projected area of the silver halide grains are tabular grains having an aspect ratio of 5 or more, and at least one polyvalent metal compound is contained in the outer periphery of the tabular grains. A silver halide emulsion in which 30% or more (number ratio) of grains have dislocation lines in the central region and the peripheral region of the main plane, and the number of dislocation lines in the peripheral region is 20 or more per grain; That at least one reduction sensitization treatment was performed during the formation of
Silver halide fine particles containing a polyvalent metal compound are added, the silver halide particles and a dispersion medium are included, and the variation coefficient of the particle size of all the silver halide particles contained is 25% or less;
50% or more of the total projected area of the silver halide grains are tabular grains having an aspect ratio of 5 or more, and 30% or more (number ratio) of the tabular grains are dislocated to the central region and the peripheral region of the main plane. And the dislocation lines in the outer peripheral region are 1
A silver halide emulsion having at least 20 grains per grain and having been subjected to at least two reduction sensitization treatments during the formation of the tabular grains, wherein the tabular grains have an average silver iodide content at the center of the grains. Region having an average silver iodide content lower than the average silver iodide content.
0% or more of the silver content, 50% or more (number ratio) of the tabular grains have dislocation lines in both the central region and the peripheral region of the main plane, and the number of dislocation lines in the peripheral region is 1 A silver halide color photographic light-sensitive material having a silver halide emulsion layer containing at least an emulsion a and an emulsion b defined on the support under the following conditions; emulsion a: silver halide The silver halide grains containing the particles and the dispersion medium have a coefficient of variation of 25% or less in the particle diameter of all silver halide grains contained therein, and 50% or more of the total projected area of the silver halide grains is
Tabular grains having an aspect ratio of 5 or more, and 30% or more (number ratio) of the tabular grains have dislocation lines in the central region and the peripheral region of the main plane, and one dislocation line in the peripheral region has one grain. Emulsion b: tabular silver halide containing silver halide grains and a dispersing medium, wherein at least 50% of the total projected area of the contained silver halide grains has an aspect ratio of 3 or more. Silver halide emulsion wherein the average grain size of the silver halide grains contained is not more than 1/2 of the average grain size of the silver halide grains of emulsion a. And a silver halide color photographic light-sensitive material having a silver halide emulsion layer containing at least the emulsion c defined in the following. And Emulsion c: total projection of the contained silver halide grains containing silver halide grains and a dispersion medium area Wherein at least 50% of the silver halide emulsion is tabular silver halide grains having an aspect ratio of 2 or more and 5 or less, wherein the emulsion a is a silver halide emulsion described in any of the above. You.

Hereinafter, each invention will be described in detail.

The tabular silver halide grains according to the present invention (hereinafter abbreviated as tabular grains) are based on three different rules, but the silver halide emulsion of the present invention may be used as long as the effects of the present invention are not impaired. May contain a silver halide emulsion consisting of other than tabular grains defined by these three types.

[0017] Of the tabular grains according to the present invention, claims 1 to
Silver halide grains containing tabular grains having dislocation lines in the central region and the peripheral region of the main plane defined by Emulsion a of claim 6 and claims 7 to 9 are hereinafter referred to as "main plane / fringe dislocation line tabular grains". Abbreviate.

Further, the silver halide grains defined in the emulsions b and c in claims 7 and 9 are referred to as "small grain tabular grains".
And the silver halide grains defined by the emulsion c of 9 are referred to as "low aspect ratio tabular grains" hereinafter.

Tabular grains are crystallographically classified as twins.

A twin is a silver halide crystal having one or more twin planes in one grain, and the classification of the form of the twin is based on the report by Klein and Moiser in Photographi Corspondents.
(Korrespondenz) Vol. 99, p100, and Vol. 100, p57.

The tabular grains in the present invention have two twin planes parallel to the main plane. The twin plane can be observed with a transmission electron microscope. The specific method is as follows. First, a silver halide photographic emulsion is coated on a support so that the contained tabular grains are substantially parallel to the main plane to prepare a sample. This is cut using a diamond cutter to obtain a thin section having a thickness of about 0.1 μm. By observing this section with a transmission electron microscope, the presence of twin planes can be confirmed.

The distance between two twin planes in the tabular grains of the present invention is determined by observing a section using a transmission electron microscope as described above. The distance between the twin planes having the shortest distance among the even twin planes parallel to the main plane is determined for each particle, and the average is obtained by averaging.

In the present invention, the distance between twin planes is a factor affecting the supersaturation state at the time of nucleation, for example, gelatin concentration, gelatin type, temperature, iodine ion concentration, pBr, p
It can be controlled by appropriately selecting a combination of various factors such as H, ion supply speed, stirring rotation speed, and the like. In general, the more the nucleation is performed in a supersaturated state, the narrower the distance between twin planes can be.

For details on the supersaturation factor, see, for example, JP-A-63-92924 or JP-A-1-21363.
The description of No. 7, etc. can be referred to.

In the present invention, the average distance between twin planes is preferably 0.01 μm to 0.05 μm, and more preferably 0.013 μm to 0.025 μm.

The thickness of the tabular grains of the present invention can be obtained by observing a section using a transmission electron microscope as described above, similarly calculating the thickness of each grain, and performing averaging. Tabular grain thickness is 0.05 μm to 1.5 μm
m is preferable, and 0.07 μm to 0.50 is more preferable.
μm.

In the present invention, the principal plane / fringe dislocation line tabular grains have an aspect ratio of 50% or more of the total projected area.
(Particle diameter / grain thickness) is 5 or more, preferably 60% or more of the total projected area has an aspect ratio of 7 or more, and more preferably 70% or more of the total projected area has an aspect ratio of 9 or more.

In the present invention, tabular grains having a small particle size are
It is necessary that 50% or more of the total projected area has an aspect ratio of 3 or more, and it is preferable that 50% or more of the total projected area has an aspect ratio of 5 or more. More preferably, 50% or more of the total projected area has an aspect ratio of 7 or more.

In the present invention, the low aspect ratio tabular grains are required to have grains having an aspect ratio of 2 or more and 5 or less, preferably 60% or more of the projected area. , Aspect ratio 2 or more and 5
The following particles, more preferably 70% of the projected area
The above are particles having an aspect ratio of 2 or more and 5 or less.

The average grain size of the main plane / fringe dislocation line tabular grains and the low aspect ratio tabular grains of the present invention is defined as the circle equivalent diameter of the projected area of the silver halide grains (having the same projected area as the silver halide grains). Although it is shown by the number average value of (diameter of a circle), it is preferably 0.1 to 5.0 μm, more preferably 0.5 to 3.0 μm.

The average particle size of the small-diameter tabular grains is also shown in the same manner, and it is necessary that the average particle size of the main-plane / fringe dislocation line tabular grains is 1/2 or less. It is preferably 5 or less.

The particle diameter can be obtained, for example, by photographing the particle with an electron microscope at a magnification of 10,000 to 70,000 and measuring the particle diameter on the print or the area at the time of projection (measurement). The number of particles shall be 1000 or more indiscriminately).

The average particle diameter is the number average of the circle-equivalent diameter of the projected area of each particle.

The main plane / fringe dislocation line tabular grains of the present invention comprise a monodispersed silver halide emulsion.

In the present invention, a monodispersed emulsion is defined as having a distribution width of 25% or less when (standard deviation / average particle size) × 100 is defined as the coefficient of variation [%] of the particle size, and is preferably 25% or less. 20% or less, more preferably 16%
% Or less. Here, the average particle size and the standard deviation are determined from the particle size defined above.

For the low aspect ratio tabular grains and small grain tabular grains of the present invention, the coefficient of variation of the particle size is preferably 35% or less, more preferably 25% or less.

The average silver iodide content of the main plane / fringe dislocation line tabular grains and the low aspect ratio tabular grains of the present invention is 1
mol% or more, preferably 1 to 10 mol%, more preferably 2 to 5 mol%. In the small grain tabular grains of the present invention, the average silver iodide content is preferably from 0 to 8 mol%, more preferably from 0 to 4 mol%.
mol%.

The tabular grains of the present invention are emulsions mainly containing silver iodobromide as described above, but may contain other compositions of silver halide, for example, silver chloride, as long as the effects of the present invention are not impaired. Can be.

The distribution state of silver iodide in the silver halide grains can be detected by various physical measurement methods. For example, as described in the Abstracts of the Annual Meeting of the Photographic Society of Japan, 1981, It can be measured by low temperature luminescence measurement, EPMA method, or X-ray diffraction method.

In the present invention, the silver iodide content and the average silver iodide content of each silver halide grain are determined by the EPMA method (Electron Probe Micro Ana).
(lyzer method). According to this method, a sample in which emulsion grains are well dispersed so as not to be in contact with each other is prepared, and element analysis of an extremely small portion can be performed by X-ray analysis using electron beam excitation for irradiating an electron beam. By determining the characteristic X-ray intensity of silver and iodine emitted from each grain by this method, the halogen composition of each grain can be determined. If the silver iodide content is determined for at least 50 grains by the EPMA method, the average silver iodide content can be determined from the average of these.

The measurement of the average silver iodide content is based on the fluorescence X
X-ray analysis, ICP (induction plasma) emission analysis, ICP
It can also be determined by measuring the silver iodide content of the whole emulsion by other well-known methods such as mass spectrometry.

The tabular grains in the present invention preferably have a more uniform silver iodide content between grains in one kind of tabular grains. When the distribution of silver iodide content among grains was measured by the EPMA method, the relative standard deviation was 30%.
%, More preferably 20% or less.

Also, as one of the constitutions of the present invention, the main plane / fringe dislocation line tabular grains have an average silver iodide content lower than the average silver iodide content of the grains at the center of the grains. The condition that the tabular grains have a silver region is required.
It can be measured by the EPMA method. Hereinafter, the conditions will be described in detail.

The tabular grains were observed perpendicular to the main plane, a line segment perpendicular to the side was drawn from the center of the main plane, and points were placed on the line at intervals of 10% or less of the length of the line. The average silver iodide content of the portion perpendicular to the main plane of the point is measured. At this time, the measurement spot needs to be narrowed to 40 nm or less. In addition, it is necessary to cool the measurement temperature to −100 ° C. or less in consideration of damage to the sample. The integration time at each measurement point shall be 30 seconds or more. In this way, the presence of a central region having an average silver iodide content lower than the average silver iodide content of the grains can be confirmed. The ratio of the low silver iodide region to the total silver content of the grains is preferably at least 40%, more preferably at least 50%,
More preferably, it is at least 60%.

The halogen composition on the surface of the tabular grains of the present invention is determined by the XPS method (X-ray Photoelectron).
(Spectroscopy method: X-ray photoelectron spectroscopy) as follows.

That is, the sample was cooled to −110 ° C. or less in an ultra-high vacuum of 1 × 10 E ^-8 torr or less, and irradiated with MgKα as a probe X-ray at an X-ray source voltage of 15 kV and an X-ray source current of 40 mA. Ag 3d5 / 2, Br 3d,
It measures about the electron of I3d3 / 2. The integrated intensity of the measured peak is used as a sensitivity factor (Sensity F
actor), and the halide composition on the silver halide surface is determined from these intensity ratios.

The silver iodide content on the surface of the main plane / fringe dislocation line tabular grains of the present invention is preferably 1 mol% or more, more preferably 2 to 20 mol%, and still more preferably 3 to 15 mol%. .

Dislocation lines of silver halide grains are described, for example, in J. Am. F. Hamilton, Photo. Sci. E
ng. 11 (1967) 57 and T.I. Shiozaw
a, J. et al. Soc. Photo. Sci. Japan35
(1972) 213 can be observed by a direct method using a transmission electron microscope at a low temperature. That is, the silver halide grains taken out from the emulsion so as not to apply enough pressure to generate dislocations on the grains are placed on a mesh for an electron microscope so as to prevent damage by electron beams (such as printout). Observation is performed by a transmission method while the sample is cooled. At this time, the thicker the particle, the more difficult it is for an electron beam to pass through, so that a method using a high-pressure electron microscope can observe more clearly. From the grain photograph obtained by such a method, the position and number of dislocation lines in each grain can be determined.

The principal plane / fringe dislocation line tabular grains of the present invention have dislocation lines in both the central region and the peripheral region of the principal plane.

The central region of the main plane of the tabular grain as referred to herein is a radius of a circle having an area equal to the main plane of the tabular grain of 8
A region having a radius of 0% and a thickness of a tabular grain in a circular portion when the center is shared. On the other hand, the peripheral region of a tabular grain refers to a region having an area corresponding to an annular region outside the central region, existing around the tabular grain, and having a thickness of the tabular grain.

The number of dislocation lines present in one particle is measured as follows. A series of particle photographs with different inclination angles with respect to the incident electrons are taken for each particle to confirm the existence of dislocation lines. At this time, if the number of dislocation lines can be counted, the number of dislocation lines is counted. For example, when dislocation lines exist densely or dislocation lines cross each other,
When the number of dislocation lines per particle cannot be counted, it is counted that there are many dislocation lines.

Most of the dislocation lines present in the central region of the principal plane of the principal plane / fringe dislocation line tabular grains of the present invention form a so-called dislocation network, and the number thereof may not be clearly counted. .

On the other hand, the dislocation lines existing in the outer peripheral region of the main plane / fringe dislocation line tabular grains of the present invention are observed as lines extending radially from the center of the grains toward the sides, but often meander. .

In the main plane / fringe dislocation line tabular grains of the present invention, at least 30% of the number ratio has dislocation lines in both the central region and the peripheral region of the main plane, and the number of dislocation lines in the peripheral region. Has 20 or more per grain, but 50% or more (number ratio) of tabular grains have dislocation lines in both the central region and the peripheral region of the main plane and the number of dislocation lines in the peripheral region. Is preferably 30 or more per grain, and 70% or more (number ratio) of tabular grains have dislocation lines in both the central region and the peripheral region of the main plane and the number of dislocation lines in the peripheral region. It is more preferred that the number of particles be 40 or more per particle.

As a method for introducing dislocation lines into silver halide grains, for example, a method in which an aqueous solution containing iodide ions such as potassium iodide and a water-soluble silver salt solution are added by double jet, or silver iodide is included. A method of adding a fine grain emulsion,
A method of adding only a solution containing iodide ions;
Known methods such as a method using an iodide ion releasing agent as described in No. 11781 can be used to form dislocations originating dislocation lines at desired positions. Among these methods, a method of adding a fine grain emulsion containing silver iodide and a method of using an iodide ion releasing agent are particularly preferable.

When an iodine ion releasing agent is used, sodium p-iodoacetamidobenzenesulfonate,
Iodoethanol, 2-iodoacetamide and the like can be preferably used.

The tabular grains of the present invention may be either grains whose latent image is mainly formed on the surface or grains mainly formed inside the grain.

The main plane / fringe dislocation line tabular grains according to the present invention may have a constitution in which at least one or more polyvalent metal compounds are contained in the above-mentioned grain outer peripheral region.

As used herein, the term "doping" or "doping" refers to the inclusion of substances other than silver ions or halide ions in silver halide grains. The term "dopant" refers to compounds that dope silver halide grains. The term "metal dopant" refers to a polyvalent metal compound that dopes the silver halide grains.

In the present invention, as a metal dopant to be contained in the peripheral region of the particles, Mg, Al, Ca, Sc,
Ti, V, Cr, Mn, Fe, Co, Cu, Zn, G
a, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru,
Rh, Pd, Cd, Sn, Ba, Ce, Eu, W, R
e, Os, Ir, Pt, Hg, Tl, Pb, Bi, In
And the like.

The metal compound to be doped is preferably selected from a single salt or a metal complex. When selecting from metal complexes, 6-coordinate, 5-coordinate, 4-coordinate and 2-coordinate complexes are preferred, and octahedral 6-coordinate and planar 4-coordinate complexes are more preferred. The complex may be a mononuclear complex or a polynuclear complex. The ligands constituting the complex include CN-, C-
O, NO ₂ -, 1,10-phenanthroline, 2,2 '
- bipyridine, SO ₃ -, ethylenediamine, NH _{3, pyridine, H 2 O, NCS-, CO-} , NO 3 -, SO
_{4 -, OH-, N 3 -} , S 2 -, F-, Cl-, Br-,
I- or the like can be used. Particularly preferred metal dopants are K ₄ Fe (CN) ₆ and K ₃ Fe (C
N) ₆ , Pb (NO ₃ ) ₂ , K ₂ IrCl ₆ , K ₃ IrC
_{l 6, K 2 IrBr 6,} InCl 3 , and the like.

The concentration distribution of the metal dopant in the silver halide grains is such that the grains are gradually dissolved from the surface to the inside,
It is determined by measuring the dopant content of each part. Specific examples include the method described below.

Prior to the determination of the metal dopant, the silver halide emulsion is pretreated as follows. First, the emulsion 3
50 ml of 0.2% actinase aqueous solution is added to 0 ml,
Stir at 40 ° C. for 30 minutes to effect gelatin degradation. This operation is repeated five times. After centrifugation, 50 ml of methanol
The washing is repeated 5 times with 50 ml of 1N nitric acid twice and 5 times with ultrapure water, and after centrifugation, only silver halide is separated. The surface portion of the obtained silver halide grains is dissolved with an aqueous ammonia solution or ammonia whose pH has been adjusted (the ammonia concentration and pH are changed according to the type and amount of silver halide to be dissolved). As a method for dissolving the extreme surface of silver bromide grains in silver halide, about 3% of the silver bromide grains can be dissolved in about 3% from the grain surface using about 10% ammonia aqueous solution 20 ml per 2 g of silver halide. At this time, the amount of silver halide dissolved was determined by centrifuging the aqueous ammonia solution after dissolving the silver halide and the silver halide, and determining the amount of silver present in the obtained supernatant by a high frequency induction plasma mass spectrometer. (ICP-MS) It can be quantified by high frequency induction plasma emission spectrometry (ICP-AES) or atomic absorption. From the difference between the amount of metal contained in the silver halide after the surface is dissolved and the total amount of the metal of the silver halide not dissolved, the amount of silver halide 1 existing at about 3%
The amount of metal per mole can be determined. As a method for determining the metal, ICP-MS which is dissolved in an aqueous solution of ammonium thiosulfate, an aqueous solution of sodium thiosulfate, or an aqueous solution of potassium cyanide and subjected to matrix matching is used.
Method, ICP-AES method, or atomic absorption method. Among these, potassium cyanide was used as a solvent, and ICP-MS (FISON Elemental A) was used as an analyzer.
In the case of using (Nalsis), about 40 mg of silver halide is dissolved in 5 ml of 0.2N potassium cyanide, and then an internal standard element Cs solution is added to 10 ppb, and the volume is adjusted to 100 ml with ultrapure water. Is used as a measurement sample. Then, the metal in the measurement sample is quantified by ICP-MS using a calibration curve obtained by combining a matrix using metal-free silver halide. At this time, the exact amount of silver in the measurement sample can be determined by ICP-AES or atomic absorption of the measurement sample diluted 100 times with ultrapure water. After such dissolution of the grain surface, the silver halide grains are washed with ultrapure water, and the dissolution of the grain surface is repeated in the same manner as described above, whereby the metal in the silver halide grain internal direction is formed. The quantity can be determined.

By combining the above-described metal determination method with particle observation by a well-known electron microscope,
The amount of metal doped in the peripheral region of the tabular grains of the present invention can be determined.

The content of the metal dopant in the tabular grains of the present invention is preferably 1 × 10 ^-9 mol to 1 × 10 ^-4 mol, more preferably 1 × 10 ^-8 mol, per mol of silver halide.
Mol to 1 × 10 ^-5 mol.

In the tabular grains of the present invention, the ratio of the amount of metal dopant contained in the peripheral region / the amount of metal dopant contained in the central region is at least 5 times, preferably 10 times.
It is at least 20 times, more preferably at least 20 times.

The effect of the metal dopant can be effectively exhibited by adding the metal dopant to the base grains in a state of being doped in the silver halide fine grain emulsion in advance. At this time, the concentration of the metal dopant per mole of the silver halide fine particles was 1
X 10 ^-1 mol to 1 x 10 ^-7 mol is preferred, and 1 x 10 ^-3 mol.
The mole is more preferably from 1 to 10 ⁵ mol.

As a method of doping silver halide fine particles with a metal dopant in advance, it is preferable to form fine particles in a state where the metal dopant is dissolved in a halide solution.

The halide composition of the silver halide fine grains may be any of silver bromide, silver iodide, silver chloride, silver iodobromide, silver chlorobromide, and silver chloroiodobromide. It is preferable to have a composition having the same main halide as the halide (the halide contained in the largest ratio in terms of mol ratio).

The silver halide fine particles containing a metal dopant can be deposited on the base grains at any time after the formation of the base grains and before the start of chemical sensitization. The period before the start is particularly preferable. By adding the fine grain emulsion in a state where the salt concentration of the base emulsion is low, the silver halide fine grains are deposited together with the metal dopant in a portion where the activity of the base grains is highest. That is, the tabular grains of the present invention can be efficiently deposited on the outer peripheral region including the corners and edges. This deposition does not mean that the silver halide fine particles are aggregated and adsorbed on the base particles as they are, but the silver halide fine particles are dissolved in the reaction system in which the silver halide fine particles and the base particles coexist, and are deposited on the base particles. Regenerating as silver halide. That is, when a part of the emulsion obtained by the above method was taken out and observed with an electron microscope, no silver halide fine particles were observed, and no epitaxial protrusions were observed on the surface of the base particles. Say.

The silver halide fine particles to be added are preferably added in an amount of 1 × 10 ⁻⁷ mol to 0.5 mol per mol of the base grains, preferably 1 × 10 ⁻⁵ mol to 1 × 10 ⁻¹ mol. More preferably, the amount of silver is added.

The physical ripening conditions for depositing the silver halide fine grains can be arbitrarily selected from 30 ° C. to 70 ° C./10 minutes to 60 minutes.

In the present invention, the main plane / fringe dislocation line tabular grains may contain, in addition to the dopant contained in the outer peripheral region, a metal dopant defined in the same manner as the central region or the central region as long as the effects of the present invention are not impaired. And it may be contained in the outer peripheral region.

In the present invention, it is preferable that the low aspect ratio tabular grains also contain a dopant in the outer peripheral region similarly to the main plane / fringe dislocation line tabular grains. In that case,
The preferred amount, type, addition method and ripening method of the dopant are in accordance with the principal plane / fringe dislocation line tabular grains.

In some cases, the main plane / fringe dislocation line tabular grains according to the present invention have a constitution in which reduction sensitization treatment (hereinafter simply referred to as reduction sensitization) is performed during grain formation.

The reduction sensitization is preferably performed twice or more, more preferably three times or more.

Reduction sensitization is carried out by adding a reducing agent to a silver halide emulsion or a mixed solution for growing grains. Alternatively, a silver halide emulsion or a mixed solution for grain growth is prepared under a low pAg of pAg7 or less, or at pH
It is carried out by ripening or growing particles under a high pH condition of 7 or more. Further, these methods can be combined. Preferably, it is performed by adding a reducing agent.

Preferred reducing agents include thiourea dioxide (formamidinesulfinic acid), ascorbic acid and its derivatives, and stannous salts. Other suitable reducing agents include borane compounds, hydrazine derivatives, silane compounds, amines and polyamines, and sulfites. The addition amount is 10 ^-2 per mol of silver halide.
It is preferably from 10 ^-8 mol to 10 ^-4 mol, more preferably from 10 ^-4 mol to 10 ^-6 mol.

For low pAg ripening, a silver salt can be added, but a water-soluble silver salt is preferred. Silver nitrate is preferred as the water-soluble silver salt. The pAg at ripening is suitably 7 or less, preferably 6 or less, more preferably 1 or less.
３3 (where pAg = −log [Ag +]).

High pH ripening is carried out, for example, by adding an alkaline compound to a silver halide emulsion or a mixed solution for grain growth. As the alkaline compound,
For example, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia and the like can be used. In the method of adding ammoniacal silver nitrate to silver halide formation, an alkaline compound other than ammonia is preferably used because the effect of ammonia is reduced.

As a method for adding the reduction sensitizer, the silver salt, and the alkaline compound for the reduction sensitization, rush addition or addition over a certain period of time may be used. In this case, the addition may be performed at a constant flow rate, or may be performed by changing the flow rate like a function. Further, the required amount may be added several times. Prior to the addition of the soluble silver salt and / or the soluble halide to the reaction vessel, it may be present in the reaction vessel, or may be mixed in a soluble halide solution and added together with the halide. Further, it may be added separately from the soluble silver salt and the soluble halide.

In a preferred configuration of the present invention, the main plane /
A fringe dislocation linear tabular grain has a silver chalcogenide nucleus-containing layer. The silver chalcogenide nucleus containing layer is preferably outside 50% by volume of the whole grain, more preferably outside 70% by volume. The chalcogenide silver nucleus-containing layer may or may not be in contact with the grain surface, but by chemical sensitization, the chemical sensitization nucleus of the formed chalcogenide and the chalcogenide silver nucleus-containing layer of the present invention may be used. The contained chalcogenide nuclei are clearly distinguished in that they themselves form latent image forming centers. That is, it is necessary that the silver chalcogenide nucleus contained in the silver chalcogenide nucleus containing layer in the present invention has lower electron capturing ability than the chemical sensitization nucleus. Silver chalcogenide nuclei satisfying such conditions are formed by a method described later.

The chalcogenide silver nuclei are formed by adding a compound capable of releasing chalcogen ions. Preferred silver chalcogen nuclei are silver sulfide nuclei, silver selenide nuclei, and silver telluride nuclei, and more preferably silver sulfide nuclei.

As the compound capable of releasing a chalcogen ion, a compound capable of releasing a sulfide ion, a selenide ion or a telluride ion is preferably used.

As compounds capable of releasing sulfide ions, thiosulfonic acid compounds, disulfide compounds, thiosulfates, sulfide salts, thiocarbamide compounds, thioformamide compounds and rhodanine compounds can be preferably used. .

As compounds capable of releasing selenide ions, those known as selenium sensitizers can be preferably used. Specifically, colloidal selenium metal, isoselenocyanates (eg, allyl isoselenocyanate, etc.), selenoureas (eg, N, N-dimethylselenourea, N, N, N′-triethylselenourea, N, N N, N'-trimethyl-N'-heptafluoroselenourea, N, N, N'-trimethyl-N'-heptafluoropropylcarbonylselenourea, N, N, N '
-Trimethyl-N'-4-nitrophenylcarbonylselenourea, etc.), selenoketones (eg, selenoacetamide, N, N-dimethylselenobenzamide, etc.), selenophosphates (eg, tri-p-triselenophosphate, etc.) And selenides (eg, diethyl selenide, diethyl diselenide, triethylphosphine selenide, etc.).

Compounds capable of releasing telluride ions include telluroureas (eg, N, N-dimethyltellurourea, tetramethyltellurourea, N-carboxyethyl-N, N'-dimethyltellurourea), phosphine Tellurides (e.g., tributylphosphine telluride, tricyclohexylphosphine telluride, triisopropylphosphine telluride, etc.), telluroamides (e.g., telluroacetamide, N, N-dimethyltellurobenzamide, etc.), telluroketones, telluroesters, Isotellocyanates and the like.

Particularly preferred as a compound capable of releasing a chalcogen ion is a thiosulfonic acid compound,
It is represented by equations [1] to [3].

[1] R-SO ₂ S-M [2] R-SO ₂ S-R ₁ [3] RSO ₂ S-Lm-SSO ₂ -R _{2 In the} formula, R, R ₁ and R ₂ are the same. And may represent an aliphatic group, an aromatic group or a heterocyclic group, M represents a cation, L represents a divalent linking group, and m is 0 or 1.

The compounds represented by the formulas [1] to [3] may be polymers containing a divalent group derived from these structures as a repeating unit, and may be R, R ₁ , R ₂ , L
May combine with each other to form a ring.

The thiosulfonate compounds represented by the formulas [1] to [3] will be described in more detail. When R, R ₁ and R ₂ are aliphatic groups, they are saturated or unsaturated, linear, branched or cyclic aliphatic hydrocarbon groups, preferably having 1 to 2 carbon atoms.
2 alkyl groups (methyl, ethyl, propyl, butyl,
Pentyl, hexyl, octyl, 2-ethylhexyl,
Decyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, isopropyl, t-butyl and the like), an alkenyl group having 2 to 22 carbon atoms (such as allyl and butenyl),
And alkynyl groups (propargyl, butynyl, etc.), which may have a substituent.

When R, R ₁ and R ₂ are aromatic groups, they contain a monocyclic or condensed ring aromatic group, and preferably have 6 to 6 carbon atoms.
20 and, for example, phenyl and naphthyl. These may have a substituent.

When R, R ₁ and R ₂ are heterocyclic groups, nitrogen,
3 having at least one element selected from oxygen, sulfur, selenium and tellurium and having at least one carbon atom
A to 15-membered ring, preferably a 3 to 6-membered ring, for example, pyrrolidine, piperidine, pyridine, tetrahydrofuran, thiophene, oxazole, thiazole, imidazole, benzothiazole, benzoxazole, benzimidazole, selenazole, benzoselenazole, tetrazole, Triazole, benzotriazole, oxadiazole, thiadiazole ring.

Examples of the substituent for R, R ₁ and R ₂ include an alkyl group (eg, methyl, ethyl, hexyl), an alkoxy group (eg, methoxy, ethoxy, octyloxy),
Aryl groups (eg, phenyl, naphthyl, tolyl),
Hydroxy group, halogen atom (for example, fluorine, chlorine,
Bromine, iodine), aryloxy group (eg, phenoxy), alkylthio group (eg, methylthio, butylthio), arylthio group (eg, phenylthio), acyl group (eg, acetyl, propionyl, butyryl, valeryl), sulfonyl group (eg, Methylsulfonyl,
Phenylsulfonyl), acylamino group (eg, acetylamino, benzoylamino), sulfonylamino group (eg, methanesulfonylamino, benzenesulfonylamino), acyloxy group (eg, acetoxy, benzoxy), carboxyl group, cyano group, sulfo group, Examples include an amino group, a —SO ₂ SM group (M represents a monovalent cation), and a —SO ₂ R ₁ group.

As the divalent linking group represented by L, C,
An atom or an atomic group containing at least one selected from N, S and O can be mentioned. Specifically, an alkylene group, an alkenylene group, an alkynylene group, an arylene group,
-O -, - S -, - NH -, - CO -, - SO 2 - is made of a single or a combination of these, and the like.

L is preferably a divalent aliphatic group or a divalent aromatic group. As the divalent aliphatic group, for example,

[0097]

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Xylylene groups and the like can be mentioned. Examples of the divalent aromatic group include a phenylene group and a naphthylene group.

These substituents may be further substituted with the substituents described above.

M is preferably a metal ion or an organic cation. Examples of the metal ion include a lithium ion, a sodium ion, and a potassium ion. Examples of the organic cation include an ammonium ion (eg, ammonium, tetramethylammonium, tetrabutylammonium), a phosphonium ion (eg, tetraphenylphosphonium), and a guanidyl group.

When the compounds represented by the formulas [1] to [3] are polymers, examples of the repeating unit include the following. These polymers may be homopolymers or copolymers with other copolymerized monomers.

[0102]

Embedded image

Specific examples of the compounds represented by the formulas [1] to [3] are described in, for example, JP-A-54-1019 and British Patent No. 9
No. 72, 211, Journal of Organi
cChemistry vol. 53, p. 396 (1
988).

The amount of the compound capable of releasing a chalcogen ion for forming a silver chalcogenide nucleus is preferably 10 ⁻² to 10 ⁻⁸ mol per mol of silver halide.
^-3 to 10 ^-6 mol is more preferred.

As a method for adding a compound capable of releasing a chalcogen ion for forming a silver chalcogenide nucleus,
Rush may be added, or may be added over a certain period of time. In this case, the addition may be performed at a constant flow rate, or may be performed by changing the flow rate like a function. Further, the required amount may be added several times. It is necessary to form the silver chalcogenide nucleus by the end of the grain formation. The formation of silver chalcogenide nuclei after grain formation may or may not be performed, but the silver chalcogenide nuclei formed after grain formation are taken in as part of the chemical sensitization nuclei formed in the chemical sensitization process, It does not substantially contribute to the effects of the present invention. Similarly, when chemical sensitization is performed inside the grain, the chalcogenide silver nuclei formed on the same surface as the chemical sensitization are
It does not substantially contribute to the effects of the present invention.

The tabular grains of the present invention are produced in the presence of a dispersion medium, that is, in an aqueous solution containing the dispersion medium. Here, the aqueous solution containing the dispersion medium refers to an aqueous solution in which a protective colloid is formed in an aqueous solution by a substance capable of forming a hydrophilic colloid (e.g., a substance that can serve as a binder), and preferably a colloidal protective substance. It is an aqueous solution containing gelatin.

In the practice of the present invention, when gelatin is used as the protective colloid, the gelatin may be either lime-treated or acid-treated. The details of the method for producing gelatin are described in Arthur Guice, The Macromolecular Chemistry of Gelatin (Academic Press, 1964).

Examples of hydrophilic colloids other than gelatin that can be used as protective colloids include, for example, gelatin derivatives, graft polymers of gelatin and other polymers,
Proteins such as albumin and casein; cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose and cellulose sulfates; sugar derivatives such as sodium alginate and starch derivatives; polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-
There are various kinds of synthetic hydrophilic high molecular substances such as copolymers such as vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole and the like.

In the case of gelatin, it is preferable to use a gelatin having a jelly strength of 200 or more in a puggy method.

As the means for forming the tabular grains of the present invention, various methods well known in the art can be used. That is, the single jet method, the controlled double jet method, the controlled triple jet method and the like can be used in any combination. However, in order to obtain monodisperse grains, silver halide grains must be formed. It is important to control pAg in the liquid phase in accordance with the growth rate of silver halide grains. pAg
As a value, an area of 7.0 to 12 is used, and preferably, an area of 7.5 to 11 can be used.

In determining the addition rate, refer to
No.-48521, and the technology described in JP-A-58-49938 can be referred to.

The preparation step of the tabular grains of the present invention is roughly classified into a nucleation step, an ripening step (nuclei ripening step) and a subsequent growing step. It is also possible to separately grow a previously prepared nuclear emulsion (or seed emulsion). The growth process may include several stages, such as a first growth process and a second growth process. The growth process of the tabular grains of the present invention means all growth processes from the nucleus (or seed) formation to the end of grain growth, and the start of growth refers to the start of the growth process.

In producing the tabular grains of the present invention, a known silver halide solvent such as ammonia, thioether, thiourea or the like may be present, or a silver halide solvent may not be used.

In the main plane / fringe dislocation line tabular grains of the present invention, in order to selectively form dislocation lines in the central region of the main plane, the pH is increased in the ripening step after nucleation and the thickness of the tabular grains is reduced. It is important to ripen so that it increases, but if the pH is too high, the aspect ratio will be too low, and it will be difficult to control the aspect ratio in a subsequent growth step. It also causes unexpected fog deterioration. Therefore, the pH / temperature of the aging step is 7.0-1.
1.0 / 40 ° C to 80 ° C, preferably 8.5 to 10.0
/ 50 ° C to 70 ° C is more preferred.

In the main plane / fringe dislocation line tabular grains of the present invention, in order to selectively form dislocation lines in the outer peripheral region, an iodine ion source (for example, It is important to increase the pAg in the grain growth after adding silver iodide fine particles and iodine ion releasing agent to the base grains. However, if the pAg is too high, so-called Ostwald ripening proceeds simultaneously with the grain growth. The monodispersity of the tabular grains is deteriorated. Therefore, the pAg at the time of forming the outer peripheral region of the tabular grains in the growth step is preferably 8 to 12, and 9.5 to 11 is preferable.
Is more preferred. When an iodine ion releasing agent is used as an iodine ion source, dislocation lines can be effectively formed in the outer peripheral region by increasing the amount of iodine ion releasing agent. The amount of the iodide ion releasing agent to be added is preferably 0.5 mol or more per mol of silver halide, more preferably 2 to 5 mol.

The tabular grains in the present invention may be those obtained by removing unnecessary soluble salts after the growth of the silver halide grains, or may be those containing them.

It is also possible to desalinate at any point during silver halide growth, as in the method described in JP-A-60-138538. When removing the salts, use Research Disclosure (Research Disc).
Closure (hereinafter abbreviated as RD) 17643 No. II. More specifically, in order to remove the soluble salt from the emulsion after the formation of the precipitate or after the physical ripening, it is possible to use a Noudel washing method performed by gelling gelatin, and inorganic salts, anionic surfactants, Anionic polymer (eg, polystyrene sulfonic acid) or gelatin derivative (eg, acylated gelatin, carbamoylated gelatin, etc.)
A precipitation method (flocculation) using the above method may be used. As a specific example, a method described in JP-A-5-72658 can be preferably used.

The tabular grains of the present invention can be chemically sensitized by a conventional method. That is, sulfur sensitization, selenium sensitization,
A noble metal sensitization method using gold or another noble metal compound can be used alone or in combination.

The tabular grains of the present invention can be optically sensitized to a desired wavelength range using a dye known as a sensitizing dye in the photographic industry. The sensitizing dyes may be used alone or in combination of two or more. A dye which has no spectral sensitizing effect by itself together with the sensitizing dye or a compound which does not substantially absorb visible light and which enhances the sensitizing effect of the sensitizing dye is contained in the emulsion. May be.

An antifoggant, a stabilizer and the like can be added to the tabular grains of the present invention. As a binder,
Advantageously, gelatin is used. Emulsion layers and other hydrophilic colloid layers can be hardened and can contain plasticizers, dispersions (latexes) of water-insoluble or soluble synthetic polymers.

In one embodiment of the light-sensitive material of the present invention, it is essential that the main plane / fringe dislocation line tabular grains and the low aspect ratio tabular grains are contained in the same photosensitive layer. The main plane / fringe dislocation line tabular grains and the low aspect ratio tabular grains may be of one type each, or may be composed of two or more types of grains having different particle diameters and compositions. In this case, it is necessary that the low aspect ratio tabular grains are contained in an amount of 5 mol% or more of the main plane / fringe dislocation line tabular grains.
ol% or more, more preferably 20 mol% or more. In that case, the main plane /
The fringe dislocation linear tabular grains preferably occupy 40 mol% or more of the total silver halide in the photosensitive layer.
ol% or more, more preferably 60 mol%
It is more preferable to occupy the above.

In another embodiment of the light-sensitive material of the present invention, it is essential that main plane / fringe dislocation line tabular grains and small-diameter tabular grains are contained in the same photosensitive layer. The main plane / fringe dislocation line tabular grains and the small-diameter tabular grains may be of one kind each, or may each be composed of two or more kinds of grains having different particle diameters and compositions. In this case, the small-diameter tabular grains are 3 m of the main plane / fringe dislocation line tabular grains.
ol% or more, preferably 5 mol% or more, more preferably 7 mol% or more. In this case, the emulsion containing the main plane / fringe dislocation line tabular grains preferably accounts for 40 mol% or more of the total silver halide in the photosensitive layer.
more preferably occupy 60 mol% or more.
% Is more preferable.

In the light-sensitive material of the present invention, as long as the effects of the present invention are not impaired, the main layer / fringe dislocation line tabular grains and the low aspect ratio tabular grains are contained in the photosensitive layer containing the main plane / fringe dislocation line tabular grains. Silver halide grains which do not correspond to any of the rules for grains and small grain tabular grains may be contained.

A coupler is used in the emulsion layer of the color photographic light-sensitive material. Further, a development accelerator, a developer, a silver halide solvent, a toning agent, a hardener, a fogging agent, an antifoggant, Compounds that release photographically useful fragments can be used, such as chemical sensitizers, spectral sensitizers, and desensitizers.

The light-sensitive material can be provided with auxiliary layers such as a filter layer, an antihalation layer, and an irradiation prevention layer. In these layers and / or the emulsion layers, dyes which flow out of the light-sensitive material or are bleached during the development processing may be contained.

The light-sensitive material can contain a matting agent, a lubricant, an image stabilizer, a formalin scavenger, an ultraviolet absorber, a fluorescent brightener, a surfactant, a development accelerator and a development retarder.

As the support, paper laminated with polyethylene or the like, polyethylene terephthalate film, baryta paper, cellulose triacetate or the like can be used.

[0128]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 << Preparation of Emulsion EM-1 >> [Nucleation Step] The following reaction mother liquor (Gr-1) in a reaction vessel
The pH was adjusted to 1.96 with 1N sulfuric acid while stirring at a stirring rotation speed of 400 rpm using a mixing and stirring device described in JP-A-62-160128. Thereafter, the liquid (S-1) and the liquid (H-1) were added at a constant flow rate for one minute by using a double jet method to form nuclei.

(Gr-1) Alkali-treated inert gelatin (average molecular weight 100,000) 40.50 g Potassium bromide 12.40 g Finish up to 16.2 L with distilled water (S-1) 862.5 g of silver nitrate 4. Finishing to 06 L (H-1) Potassium bromide 604.5 g Finishing to 4.06 L with distilled water [Aging step] After the above nucleation step, add the (G-1) solution, and take 30 minutes to reach 60 ° C. The temperature rose. During this time, the silver potential of the emulsion in the reaction vessel (measured with a silver ion selective electrode using a saturated silver-silver chloride electrode as a reference electrode) was controlled at 6 mV using a 2N potassium bromide solution. Subsequently, the pH was adjusted to 9.3 by adding an aqueous ammonia solution, and after further holding for 7 minutes, the pH was adjusted to 6.1 using an aqueous acetic acid solution. During this period, the silver potential was adjusted to 6 mV using a 2N potassium bromide solution.
Was controlled.

(G-1) Alkali-treated inert gelatin (average molecular weight 100,000) 173.9 g HO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10 wt% methanol solution 5.80 ml Finish to 4.22 L with distilled water [Growth step] After the ripening step is completed, the above (S-1) liquid and (H-1) While accelerating the flow rate of the solution (the ratio of the addition flow rate at the end to the addition at the start is about 12 times)
Added in 37 minutes. After the completion of the addition, the solution (G-2) was added, and the stirring speed was adjusted to 550 rpm, and then the solution (S-2) and the solution (H-2) were accelerated while increasing the flow rates (at the time of completion). (The ratio of the addition flow rates at the start was about twice). During this time, the silver potential of the emulsion was controlled at 6 mV using a 2N potassium bromide solution. After the addition was completed, the emulsion temperature in the reaction vessel was lowered to 40 ° C. over 15 minutes. Thereafter, the silver potential in the reaction vessel was adjusted to −39 mV using a 3N potassium bromide solution. Subsequently, 407.5 g of solution (F-1) was added, and then solution (S-2) and solution (H-) were added. 3) The solution was added over 25 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the start was about 1.2 times).

(S-2) Silver nitrate 2.10 kg Finished to 3.53 L with distilled water (H-2) Potassium bromide 859.5 g Potassium iodide 24.45 g Finished to 2.11 L with distilled water (H-3) Potassium bromide 587.0 g Potassium iodide 8.19 g Finish up to 1.42 L with distilled water (G-2) Ossein gelatin 284.9 g HO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10 wt% methanol solution 7.75 ml Finish up to 1.93 L with distilled water (F-1) 3 wt% gelatin and silver iodide particles Fine particle emulsion (*) having a mean particle size of 0.05 μm 407.5 g * The preparation method of the fine particle emulsion F-1 is as follows: A 6.0% by weight gelatin solution containing 0.06 mol of potassium iodide 5000m 1 to 7.06 moles of silver nitrate,
Aqueous solution containing 7.06 moles of potassium iodide, 2
000 ml was added over 10 minutes. During the formation of fine particles, the pH was controlled at 2.0 using nitric acid, and the temperature was controlled at 40 ° C. After the particles are formed, the pH is adjusted using an aqueous sodium carbonate solution.
Was adjusted to 6.0. The finished weight was 12.53 kg.

After the completion of the particle growth,
After desalting according to the method described in No. 58, gelatin was added and dispersed, and the pH was adjusted to 5.80 and pAg at 40 ° C.
Was adjusted to 8.06. EM-
Let it be 1.

From the electron micrograph of the obtained emulsion particles,
It was confirmed that the tabular grains had an average particle size of 1.50 μm (average value of the circle diameter of the projected area), an aspect ratio of 7.4 (60% of the total projected area), and a particle size distribution of 15.0%.

<< Preparation of Emulsion EM-2 >> In the nucleation step and the ripening step, grains were formed in the same manner as in EM-1, and then the growth step was changed as follows to prepare emulsion EM-2.

[Growth Step] After the ripening step, the (S-1) solution and (H-1) solution are successively accelerated by the double jet method while increasing the flow rates (the addition flow rates at the end and at the start). (The ratio is about 12 times). (G-
2) After adding the liquid and adjusting the stirring rotation speed to 550 rpm, the (S-2) liquid and the (H-2) liquid were successively accelerated while increasing the flow rates (the addition flow rate at the end and at the start). The ratio is about 2
Fold) for 40 minutes. During this time, the silver potential of the emulsion was 2N.
Was adjusted to 6 mV using a potassium bromide solution of After the addition was completed, the emulsion temperature in the reaction vessel was lowered to 40 ° C. over 15 minutes. Then, the liquid (Z-1) and then (S
S) The solution was added, the pH was adjusted to 9.3 using an aqueous solution of potassium hydroxide, and iodine ions were released while aging for 4 minutes. Thereafter, the pH was adjusted to 5.0 using an aqueous acetic acid solution, and then the silver potential in the reaction vessel was adjusted to −39 mV using a 3N potassium bromide solution. 3) The solution was added over 25 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the start was about 1.2 times).

(S-2) Silver nitrate 2.10 kg Finished to 3.53 L with distilled water (H-2) Potassium bromide 859.5 g Potassium iodide 24.45 g Finished to 2.11 L with distilled water (H-3) Potassium bromide 587.0 g Potassium iodide 8.19 g Finish up to 1.42 L with distilled water (G-2) Ossein gelatin 284.9 g HO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10% by weight methanol solution 7.75 ml Finish up to 1.93 L with distilled water (Z-1) 83.4 g of sodium p-iodoacetamidobenzenesulfonate Finish with 1.00 L with distilled water (SS) 29.0 g with sodium sulfite Finish with 0.30 L with distilled water Desalting treatment according to the method of mounting, then gelatin was added dispersion, the pH at 40 ° C. 5.80, the pAg was adjusted to 8.06. The emulsion thus obtained is designated as EM-2.

From an electron micrograph of the obtained emulsion particles,
It was confirmed that the tabular grains had an average particle size of 1.51 μm (average value of the circle-converted diameter of the projected area), an aspect ratio of 7.2 (60% of the total projected area), and a particle size distribution of 14.5%.

<< Preparation of Emulsion EM-3 >> In the method for producing Emulsion EM-2, the grains were grown by controlling the silver potential in the reaction vessel to 6 mV over the entire growth step, and the others were combined with Emulsion EM-2. Emulsion EM-3 having a reduced aspect ratio was prepared by the same manufacturing method. From the electron micrograph of the obtained emulsion particles, the average particle size was 1.18 μm (the average value of the circle diameter of the projected area), the aspect ratio was 4.1 (60% of the total projected area), and the particle size distribution was 15.6%. Was confirmed to be tabular grains.

<< Preparation of Emulsion EM-4 >> In the method for producing Emulsion EM-2, the silver potential in the reaction vessel was controlled at −10 mV throughout the entire growth process to grow the grains, and otherwise, the emulsion EM-2 was used. Emulsion EM-4 in which the variation coefficient of the particle size was deteriorated was prepared by the same production method as in Example 1. From the electron micrograph of the obtained emulsion particles, the average particle size was 1.51 μm (the average value of the projected area in terms of circle), the aspect ratio was 7.2 (60% of the total projected area), and the particle size distribution was 26.3%. Was confirmed to be tabular grains.

<< Preparation of Emulsion EM-5 >> In the method for producing Emulsion EM-2, except that Solution (H-2) and Solution (H-3) in the growth step were changed as follows.
Emulsion EM-5 was prepared in the same manner as in Preparation Example 2.

(H-2) Potassium bromide 852.5 g Potassium iodide 36.78 g Finished to 2.11 L with distilled water (H-3) Potassium bromide 591.5 g Finished to 1.42 L with distilled water From the electron micrograph of the emulsion grains, it was found that the average grain size was 1.
50 μm (average diameter of projected area in circle), aspect ratio 7.0 (60% of total projected area), particle size distribution 14.9
% Tabular grains.

<< Preparation of Emulsion EM-6 >> In the method for producing Emulsion EM-2, p
The H was adjusted to 6.1, and otherwise the same manufacturing method as that for the emulsion EM-2 was used to prepare an emulsion EM-6 having no dislocation line in the central region of the main plane of the tabular grains. From the electron micrograph of the obtained emulsion particles, the average particle size was 1.53 μm (the average value of the circle diameter of the projected area), the aspect ratio was 7.4 (60% of the total projected area), and the particle size distribution was 15.7%. Was confirmed to be tabular grains.

<< Preparation of Emulsion EM-7 >> In the method for producing Emulsion EM-2, it is used in the growth step (Z-1)
Emulsion EM-7 having no dislocation line in the outer peripheral region was prepared by the same manufacturing method as emulsion EM-2 except that no liquid was added. From the electron micrograph of the obtained emulsion particles, the average particle size was 1.52 μm (the average value of the circle diameter of the projected area), the aspect ratio was 7.2 (60% of the total projected area), and the particle size distribution was 15.4%. Was confirmed to be tabular grains.

Table 1 summarizes the characteristics of the emulsions EM-1 to EM-7.

[0146]

[Table 1]

<< Preparation of Emulsions EM-1B to EM-7B >> In the process for producing the emulsions EM-1 to EM-7, in the step of adding and dispersing gelatin after desalting, (F-2)
And then aging at 50 ° C. for 20 minutes.
Emulsions EM-1B to EM-1 in the same manner as -1 to EM-7
M-7B was produced.

(F-2) 4.70 g of silver bromide fine particles doped with K ₂ IrCl ₆ * The preparation method of fine particle emulsion F-2 is as follows: 6.0 weight containing 0.06 mol of potassium bromide % Gelatin solution 5
An aqueous solution 20 containing 7.06 mol of silver nitrate in 000 ml
00 ml, 7.06 mol of potassium bromide and 4.4 ×
2000 ml of an aqueous solution containing 10 ^-3 mol of K ₂ IrCl ₆
Was added over 10 minutes. During the formation of fine particles, the pH was controlled at 2.0 using nitric acid, and the temperature was controlled at 40 ° C. After the formation of the particles, the pH was adjusted to 6.0 using an aqueous solution of sodium carbonate. The finished weight was 12.53 kg.

<< Preparation of Photosensitive Material >> On a triacetyl cellulose film support provided with an undercoat layer, layers having the following compositions were sequentially formed from the support side to prepare a multilayer color photographic light-sensitive material sample 101. The addition amount is 1 m ²
Expressed in grams per unit. However, silver halide and colloidal silver were converted to the amount of silver, and the sensitizing dye (indicated by SD) was silver 1
It was shown in moles per mole.

First Layer (Antihalation Layer) Black Colloidal Silver 0.20 UV-1 0.3 Gelatin 1.3 Second Layer (Intermediate Layer) CM-1 0.1 OIL-1 0.2 Gelatin 0.7 Third layer (low-sensitivity red-sensitive layer) Silver iodobromide a 0.006 Silver iodobromide b 0.12 Silver iodobromide c 0.12 SD-1 2.2 × 10 ^-5 SD- ²³ 0.0 × 10 ^-5 SD-3 1.0 × 10 ^-4 SD-4 1.0 × 10 ^-4 SD-5 2.0 × 10 ^-4 C-1 0.20 CC-1 0.005 OIL- 2 0.2 AS-2 0.001 Gelatin 0.5 Fourth layer (medium sensitivity red-sensitive layer) Silver iodobromide d 0.3 Silver iodobromide a 0.4 Silver iodobromide b 0.7 SD-1 1.7 × 10 ^-4 SD-4 2.5 × 10 ^-4 SD-5 3.0 × 10 ^-4 C-1 1.0 CC-1 0.08 DI-1 0.02 DI- 5 0.01 OIL- 2 0.9 AS-2 0.005 Gelatin 2.1 Fifth layer (high-sensitivity red-sensitive layer) Silver iodobromide e 1.4 Silver iodobromide a 0.1 SD-1 1.5 × 10 ^-5 SD-2 6.5 × 10 ^-5 SD-4 2.8 × 10 ^-4 SD-5 2.5 × 10 ^-5 C-1 0.04 C-2 0.04 C-3 0.1 CC-1 0.03 Y-1 0.02 DI-1 0.02 DI-3 0.01 OIL-1 0.01 OIL-2 0.3 Liquid paraffin 0.3 AS-2 0.005 Gelatin 2. 00 6th layer (intermediate layer) AS-1 0.3 OIL-1 0.4 gelatin 1.00 7th layer (intermediate layer) Gelatin 0.5 8th layer (low sensitivity green color sensitive layer) iodobromide Silver b 0.1 Silver iodobromide c 0.1 SD-6 6.0 × 10 ^-5 SD-7 5.5 × 10 ^-4 M-1 0.2 CM-1 0.03 DI-30. 0001 OIL 1 0.2 AS-2 0.005 AS-3 0.05 Gelatin 1.0 Ninth layer (medium-speed green color-sensitive layer) Silver iodobromide d 0.5 Silver iodobromide a 0.4 Silver oxide b 0.4 SD-6 3.5 × 10 ^-5 SD-7 1.7 × 10 ^-4 SD-8 2.0 × 10 ^-4 SD-9 1.5 × 10 ^-4 SD-10 2 0.5 × 10 ^-5 M-1 0.06 M-2 0.2 M-3 0.1 CM-1 0.05 CM-2 0.05 DI-2 0.02 DI-3 0.004 OIL- 10.5 AS-2 0.02 AS-3 0.02 Gelatin 2.0 10th layer (high-sensitivity green color-sensitive layer) Emulsion EM-1 1.4 SD-6 3.0 × 10 ^-5 SD -8 3.0 × 10 ^-4 SD-9 3.0 × 10 ^-5 SD-10 3.5 × 10 ^-5 M-1 0.1 M-3 0.04 CM-2 0.01 DI-2 0.005 DI-3 0.005 OI -1 0.3 Liquid paraffin 0.5 AS-2 0.01 AS-3 0.03 Gelatin 1.4 11th layer (yellow filter layer) Yellow colloidal silver 0.05 OIL-1 0.2 AS-10 0.2 X-1 0.1 gelatin 0.8 12th layer (intermediate layer) X-1 0.05 gelatin 0.5 13th layer (low-sensitivity blue-sensitive layer) Silver iodobromide f 0.2 iodine Silver bromide g 0.1 Silver iodobromide h 0.17 SD-11 2.5 × 10 ^-4 SD-12 5.5 × 10 ^-4 SD-13 1.5 × 10 ^-4 Y-1 0 DI-4 0.02 OIL-1 0.5 AS-2 0.005 X-1 0.1 X-2 0.2 Gelatin 1.8 14th layer (highly sensitive blue-sensitive layer) iodobromide Silver i 1.5 Silver iodobromide g 0.1 SD-11 5.0 × 10 ^-5 SD-12 1.0 × 10 ^-4 SD-13 5.0 × 10 ^-5 Y-1 0.2 OIL-1 0.01 Liquid paraffin 0.3 AS-2 0.005 X-1 0.15 X-2 0.2 Gelatin 1.40 15th layer (first protective layer) Silver iodobromide j 0.3 UV-1 0.10 UV-2 0.06 Liquid paraffin 0.5 X-1 0.15 Gelatin 1.5 Sixteenth layer (second protective layer) PM-1 0.15 PM-2 0.05 WAX- 1 0.02 Gelatin 0.56 In addition to the above composition, compound SU-1, SU-2, viscosity modifier V-1, hardening agents H-1, H-2, and stabilizer ST-
1, ST-2, antifoggant AF-1, AF-2, AF
-3, dyes AI-1, AI-2, AI-3 and fungicide A
se-1 was appropriately added to each layer.

The characteristics of the silver iodobromide used are shown below. (In the following list, the volume particle size represents the length of one side of a cube having the same volume as the particles.) Average volume particle size (μm) Average AgI (mol%) Diameter / thickness ratio Silver iodobromide a 0.56 2.4 5.5 5.5 Silver iodobromide b 0.38 8.0 (twin octahedron) Silver iodide c 0.27 2.0 1.0 Silver iodobromide d 0.70 2.4 6.4 Silver iodobromide e 1.0 2.9 6.4 Silver iodobromide f 0.74 3. 5 6.2 Silver iodobromide g 0.44 4.2 6.1 Silver iodobromide h 0.3 1.9 5.5 Silver iodobromide i 1.0 8.0 2.0 Silver iodobromide j 0.03 2.0 1.0 For silver iodobromide a, d, e, f, and g, emulsion EM
The particle size was adjusted with reference to the production method of -6. For other silver iodobromide, see JP-A-61-6643,
No. 61-14630, No. 61-112142, No. 6
2-157024, 62-18556, 63-
No. 163451, No. 63-220238, No. 63-3
No. 11244, JP-A-3-200245, and JP-A-3-20
No. 9236, No. 5-210190, No. 5-28921
No. 4, No. 8-69064, Japanese Patent Application No. 7-331774, and the like.

Emulsion EM-1 was added with the above-mentioned sensitizing dye, aged and then added with triphosphine selenide, sodium thiosulfate, chloroauric acid and potassium thiocyanate. Chemical sensitization was applied to optimize.

The other silver iodobromide was similarly subjected to spectral sensitization and chemical sensitization according to a conventional method.

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[0158]

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[0159]

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[0161]

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[0163]

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In the same manner as in Sample 101, the emulsion EM-1 in the tenth layer was changed to emulsions EM-2 to EM-7, and Samples 102 to 107 were changed to emulsions EM-1B to EM-7B. Thus, 101B to 107B were produced.

<< Evaluation of Photographic Performance >> Each of the obtained samples was subjected to wedge exposure for sensitometry using green light (G), and the relative sensitivity, granularity, and green optical density were measured.
Pressure characteristics and reciprocity failure characteristics were evaluated.

The relative sensitivity is calculated as the relative value of the reciprocal of the exposure amount that gives the density of D _min (minimum density) +0.15 within 1 minute after the exposure (1/200 ″). , The sensitivity of sample 101 was set to 100 (a value larger than 100 indicates higher sensitivity).

The graininess was evaluated by using a relative sensitivity evaluation sample.
The density was expressed as a relative value of the standard deviation (RMS value) of the fluctuation of the density value generated when scanning the density of _min + 0.5 with a microdensitometer having an aperture scanning area of 250 μm ² . The smaller the RMS value is, the better the graininess is and the more effective it is. Sample 10
The RMS value of 1 is shown as a value with 100 (the smaller the value is, the better the value is 100).

The pressure characteristic is 23 ° C./55% (relative humidity)
After scanning at a constant speed by applying a load of 5 g to a needle having a tip having a curvature radius of 0.025 mm using a scratch strength tester (manufactured by Shinto Kagaku) under the conditions described above, exposure (1/200 ″) was performed. , make the following development processing, D _min, and the concentration of D _min +0.4, partial change in concentration of exerted load respectively ΔD1
(D _min ) and ΔD 2 (D _min +0.4) were obtained, and the values were set such that ΔD 1 and ΔD 2 of the sample 101 were each set to 100 (the smaller the value, the better the value of 100). ).

The reciprocity failure property was determined for each sample by exposure to green light (G) for 8 seconds (low illuminance exposure) or 1/10.
000 seconds exposure (high illuminance exposure), and after the following development processing within 1 minute after exposure, _Dmin (minimum density) + 0.
Calculated as the relative value of the reciprocal of the exposure amount giving a density of 15;
The sensitivity is shown as a value with the sensitivity of the sample 101 being 100 (a value larger than 100 indicates higher sensitivity).

<< Reference Color Development Processing >> Processing Step Processing Time Processing Temperature Replenishment Amount * Color Development 3 min 15 sec 38 ± 0.3 ° C. 780 cc Bleaching 45 sec 38 ± 2.0 ° C. 150 cc Set 1 min 30 sec 38 ± 2.0 ° C. 830 cc Stability 60 seconds 38 ± 5.0 ° C. 830 cc Drying 1 minute 55 ± 5.0 ° C. * The replenishing amount is a value per 1 m ² of the photosensitive material.

The following color developing solutions, bleaching solutions, fixing solutions, stabilizing solutions and replenishers were used.

Color developer water 800 cc Potassium carbonate 30 g Sodium bicarbonate 2.5 g Potassium sulfite 3.0 g Sodium bromide 1.3 g Potassium iodide 1.2 mg Hydroxylamine sulfate 2.5 g Sodium chloride 0.6 g 4-amino- 3-methyl-N-ethyl-N- (β-hydroxylethyl) aniline sulfate 4.5 g Diethylenetriaminepentaacetic acid 3.0 g Potassium hydroxide 1.2 g Add water to make 1 L, and use potassium hydroxide or 20% sulfuric acid. And adjust the pH to 10.06.

Color developing replenisher water 800 cc Potassium carbonate 35 g Sodium bicarbonate 3 g Potassium sulfite 5 g Sodium bromide 0.4 g Hydroxylamine sulfate 3.1 g 4-Amino-methyl-N-ethyl-N- (β-hydroxylethyl) Aniline sulfate 6.3 g Potassium hydroxide 2 g Diethylenetriaminepentaacetic acid 3.0 g Add water to make 1 L, and adjust to pH 10.18 using potassium hydroxide or 20%.

Bleaching solution water 700 cc 1,3-diaminopropanetetraacetic acid ammonium iron (III) salt 125 g ethylenediaminetetraacetic acid 2 g sodium nitrate 40 g ammonium bromide 150 g glacial acetic acid 40 g Add water to make 1 L, and use ammonia water or glacial acetic acid. Adjust to pH 4.4.

Bleach replenisher water 700 cc 1,3-diaminopropanetetraacetic acid iron (III) ammonium 175 g ethylenediaminetetraacetic acid 2 g sodium nitrate 50 g ammonium bromide 200 g glacial acetic acid 56 g After adjusting the pH to 4.4 using aqueous ammonia or glacial acetic acid Add water to make 1L.

Fixing solution water 800 cc Ammonium thiocyanate 120 g Ammonium thiosulfate 150 g Sodium sulfite 15 g Ethylenediaminetetraacetic acid 2 g After adjusting the pH to 6.2 using aqueous ammonia or glacial acetic acid, add water to make 1 L.

Fixing replenisher water 800 cc Ammonium thiocyanate 150 g Ammonium thiosulfate 180 g Sodium sulfite 20 g Ethylenediaminetetraacetic acid 2 g After adjusting the pH to 6.5 using aqueous ammonia or glacial acetic acid, add water to make 1 L.

Stabilizing solution and stabilizing replenisher water 900 cc para-octylphenyl polyoxyethylene ether (n = 10) 2.0 g dimethylol urea 0.5 g hexamethylenetetramine 0.2 g 1,2-benzoisothiazolin-3-one 0.1 g Siloxane (UCC L-77) 0.1 g Aqueous ammonia 0.5 cc Add water to make 1 L, and adjust the pH to 8.5 with ammonia water or 50% sulfuric acid.

Table 2 shows the above results.

[0180]

[Table 2]

As shown in Table 2, in the sample of the present invention, the reciprocity failure property was improved by the addition of iridium-containing fine particles (with or without B at the end of the sample name) without significantly impairing the relative sensitivity. At the same time, the pressure characteristics are also improved. This is particularly noticeable in the sample 102B.

Example 2 << Preparation of Emulsions EM-2C, EM-5C and EM-6C >> In the growth step of the emulsion EM-2B, the solution (S-1) and (H
-1) At the end of the addition of the solution, rush addition of the following solution (R-1) is performed, and the remaining of the solution (S-2) is 498c.
EM-2C was produced in the same manner as EM-2B, except that at the time point of reaching c, the following solution (T-1) was added by rush.

Similarly, EM-5C was manufactured based on the EM-5B manufacturing method, and EM-5C was manufactured based on the EM-6B manufacturing method.
6C was produced.

(R-1) thiourea dioxide 26.6 mg distilled water 46.6 ml (T-1) sodium ethanethiosulfonate 879.9 mg distilled water 293.3 ml << emulsions EM-2D, EM-5CD, EM-6D Preparation of
In the growth process of the emulsion EM-2B, at the end of the addition of the solution (S-1) and the solution (H-1), the following (R-2) solution is rush-added, and the remaining amount of the solution (S-2) Is 3.33L
(R-3) solution was added by lashing at the time when the temperature became, the following (R-4) was added by lashing immediately before the temperature was lowered to 40 ° C, and the remaining (S-2) solution was 498 cc.
EM-2D was produced in the same manner as EM-2B except that the above solution (T-1) was added by rushing at the time when the above was reached.

Similarly, EM-5D was manufactured based on the EM-5B manufacturing method, and EM-5D was manufactured based on the EM-6B manufacturing method.
6D was produced.

(R-2) thiourea dioxide 6.65 mg distilled water 11.7 ml (R-3) thiourea dioxide 8.87 mg distilled water 15.5 ml (R-4) thiourea dioxide 11.1 mg distilled water 19. 4 ml << Preparation of photosensitive material >> A sample was prepared in the same manner as in Sample 101 of Example 1, except that silver iodobromide e was used for the emulsion of the tenth layer and EM-2B was used instead of silver iodobromide i of the fourteenth layer. A sample 202B was manufactured in the same manner as in Sample 101. Similarly, EM-2C, EM-2D, and EM-2C were used instead of silver iodobromide i in the fourteenth layer.
-5B, EM-5C, EM-5D, EM-6B, EM-
6C and EM-6D, the sample 202C and the sample 202C, respectively.
02D, 205B, 205C, 205D, 206B, 2
06C and 206D were produced.

<< Evaluation of Photographic Performance >> Each of the obtained samples was subjected to wedge exposure for sensitometry using blue light (B), and the relative sensitivity, reciprocity failure property and latent image preservability of blue optical density were measured. Was evaluated. Example 1 concerning development processing, relative sensitivity, and evaluation of reciprocity failure property
Was performed in the same manner as described above.

The latent image storability was evaluated by exposure (1/20
0 "), and then stored for 30 days at a temperature of 25 ° C. and a relative humidity of 60%, and then subjected to color development processing, and the reciprocal of the exposure amount giving a density of D _min (minimum density) +0.15 is A,
Stored in a freezer (−20 ° C.) until immediately before development, and evaluated the latent image preservability at the same time as the D _min (minimum density) +
The reciprocal of the exposure amount that gives a density of 0.15 is B, and (A−
B) / B × 100 was determined as an evaluation scale of latent image storability (the closer to 0, the better the latent image storability).

Relative sensitivity and reciprocity failure characteristics were measured for sample 202B.
Was set to 100 and the relative evaluation was made.

Table 3 shows the results.

[0191]

[Table 3]

As shown in Table 3, in the sample of the present invention, the improvement of the relative sensitivity and the improvement of the storage stability of the latent image due to the reduction sensitization were remarkable, and the reciprocity failure property was also improved. In particular, the improvement effect is remarkable in emulsion samples which have been subjected to reduction sensitization a plurality of times.

Example 3 << Preparation of Emulsion EM-8 >> A small grain tabular emulsion EM-8 was prepared by the following method.

(Solution A) Ossein gelatin 24.2 g Potassium bromide 10.75 g Nitric acid (1.2 N) 118.6 ml HO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) CH ₂ O) _19.8 (CH ₂ CH ₂ O) finish _{n H (m + n = 9.77} ) of 10 9686Ml in weight percent methanol solution 6.78ml of distilled water (B solution) finish 2826ml with silver nitrate 1200.0g distilled water (C solution) potassium bromide 823.8 g Potassium iodide 23.46 g Finished to 2826 ml with distilled water (Solution D) Ossein gelatin 120.9 g Finished to 2130 ml with distilled water (Solution E) 76.48 g potassium bromide Finished to 376 ml with distilled water (Solution F) ) Potassium hydroxide 10.06 g Finish up to 340 ml with distilled water. Solution A stirred vigorously at 35 ° C, 464 ml of solution B and C Was added over 2 minutes by the double jet method 464Ml, it was performed to form the core particles. During this time, E
The solution was used to keep the pAg at 9.82.

Thereafter, the temperature was raised to 60 ° C. over 66 minutes. During the temperature rise, when the temperature in the reaction system rose to 55 ° C., Solution D was added alone over 7 minutes. Furthermore,
When the temperature rises to 60 ° C., solution F is added in one minute,
Subsequently, 2362 ml of solution B and 2362 ml of solution C were added over 43 minutes. Immediately after the start of the temperature rise, the pAg was maintained at 8.97 using the solution E.

After the addition of the solution B and the solution C, desalting was performed according to a conventional method. To the emulsion after desalting, a 10% by weight aqueous solution of gelatin was added, and the mixture was stirred and dispersed at 55 ° C. for 30 minutes, and then distilled water was added to prepare 5360 g of an emulsion.

The emulsion grains were observed by an electron microscope, and were found to be tabular grains having two twin planes parallel to each other. These seed emulsion grains had an average grain size of 0.445 μm, and 50% of the total projected area were tabular grains having an aspect ratio of 5.0.

<< Preparation of Emulsion EM-9 >> A low aspect ratio tabular emulsion EM-9 was prepared by the following method.

(Gr-2) Alkali-treated inert gelatin (average molecular weight 100,000) 22.4 g Emulsion Em-8 0.4129 mol Potassium bromide 0.597 g HO (CH ₂ CH ₂ O) _m (CH (CH ₃ ) (CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10% by weight methanol solution 0.497 ml Finish up to 0.716 L with distilled water (S-4) 512.4 g of silver nitrate with distilled water Finishing to 0.862 L (H-4) 359.0 g of potassium bromide Finishing to 0.862 L with distilled water (F-1) Consisting of 3% by weight of gelatin and silver iodide particles (average particle size 0.05 μm) Fine particle emulsion (the production method is the same as in Example 1) 149.4 g The solution (Gr-2) kept at 75 ° C. was EAg 29 mV, pH
The silver iodide content was adjusted to 4.65, and with stirring, a silver amount of 23% with respect to the final total silver amount (including the silver amount of EM-8 as a seed emulsion) was added, and the silver iodide content was reduced to 2 mol%. So that (S
-4) The ratio of the solution (H-4) and the solution (F-1) was adjusted, and the addition by the triple jet method was performed over 39 minutes. Subsequently, a similar amount was added over 45 minutes so that a silver amount of 49% based on the final total silver amount was added and the silver iodide content became 1 mol%. Next, the addition was stopped, the temperature was lowered to 60 ° C. in 15 minutes, the EAg was adjusted to −44 mV using an aqueous potassium bromide solution, and the remaining (F-1) solution (8
9.8 g) was added over 2 minutes. After another two minutes,
The addition of the solution (S-4) and the solution (H-4) was restarted, and the remaining solution (S-4) and the solution (H-
4) The solution was added.

Here, the liquid (S-4), the liquid (H-4) and the liquid (F-4) at the time of addition of the triple jet or the double jet were used.
-1) The addition flow rate of the liquid is changed as a function of time in accordance with the desired halide composition and the critical growth rate of the silver halide grains, and the generation of small grains in addition to the growing seed crystal and An appropriate addition rate was controlled so as not to be polydispersed by Ostwald ripening.

After the completion of the above-mentioned grain growth, a method described in JP-A-5-726
After desalting according to the method described in No. 58, gelatin was added and dispersed, and the pH was adjusted to 5.80 and pAg at 40 ° C.
Was adjusted to 8.06. EM-
9 is assumed.

From the electron micrograph of the obtained emulsion particles,
The average particle size is 0.84 μm (the average value of the circle diameter of the projected area), and 60% of the total projected area has an aspect ratio of 2 or more and 5
It was confirmed that the tabular grains were composed of the following tabular grains and had a particle size distribution of 24.5%.

<< Preparation of Photosensitive Material and Evaluation of Photographic Performance >> In Sample 101 of Example 1, silver iodobromide e was used for the emulsion of the tenth layer, and silver iodobromide e and a of the fifth layer were measured. Except that the sample 301 is replaced by
To 306 were produced.

Each of the obtained samples was subjected to wedge exposure for sensitometry using red light (R), and the relative sensitivity and development processing stability of the red optical density were evaluated.

The relative sensitivity was evaluated in the same manner as in Example 1, and was expressed as a relative value with the sensitivity of Sample 301 being 100.

Regarding the stability of the development processing, the color development step of the development processing step was performed by active development at a temperature of + 1 ° C. and a time of 30 seconds, and the variation from the sensitivity in the reference development was determined as a relative value. The fluctuation was indicated by a value of 100 (smaller values indicate better development processing stability).

Table 4 shows the results.

[0208]

[Table 4]

As shown in Table 4, in the comparative sample using the emulsion EM-6 having dislocation lines only in the outer peripheral region, the development stability was slightly improved due to the particle mix, but the sensitivity was deteriorated. In the case of the sample of the present invention using EM-2 having dislocation lines in both the outer peripheral region and the central region, the two types of emulsions are present in the same photosensitive layer, so that the development is drastically performed without deteriorating the sensitivity. Processing stability can be improved.

[0210]

The silver halide emulsion of the present invention has excellent latent image preservability and reciprocity failure characteristics in addition to sensitivity, graininess and pressure characteristics, and silver halide color photographic materials using these are further developed. Excellent in process fluctuation stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03C 1/09 G03C 1/09 7/00 510 7/00 510

Claims (9)

[Claims] Claims 1. A silver halide grain and a dispersion medium, wherein all silver halide grains contained have a coefficient of variation of 25% or less in particle size, and 50% or more of the total projected area of the silver halide grains. A tabular grain having an aspect ratio of 5 or more, containing at least one polyvalent metal compound in the outer periphery of the tabular grain, and 30% or more (number ratio) of the tabular grain is centered on the main plane. A silver halide emulsion having dislocation lines in a region and an outer peripheral region, wherein the number of dislocation lines in the outer peripheral region is 20 or more per grain. 2. During the formation of said tabular grains, at least one
2. A reduction sensitization process performed twice.
The silver halide emulsion according to the above. 3. The silver halide emulsion according to claim 1, wherein silver halide fine particles containing a polyvalent metal compound are added during the formation of the tabular grains. 4. A silver halide grain and a dispersion medium, wherein all silver halide grains contained have a variation coefficient of 25% or less in particle diameter, and 50% or more of the total projected area of said silver halide grains. Are tabular grains having an aspect ratio of 5 or more, and 30% or more (number ratio) of the tabular grains have dislocation lines in the central region and the peripheral region of the main plane, and the dislocation lines in the peripheral region are 1%. 20. A silver halide emulsion comprising at least 20 grains per grain and having been subjected to at least two reduction sensitization treatments during the formation of the tabular grains. 5. The tabular grains have, in the center of the grains, a region having an average silver iodide content lower than the average silver iodide content of the grains, and the low silver iodide regions are formed by the total silver of the grains. 4 for quantity
2. The composition according to claim 1, wherein the silver content is 0% or more.
5. The silver halide emulsion according to 2, 3, or 4. 6. More than 50% (number ratio) of the tabular grains have dislocation lines in both the central region and the peripheral region of the main plane, and the number of dislocation lines in the peripheral region is 3 per particle.
5. The method according to claim 1, wherein the number is zero or more.
Or the silver halide emulsion of 5 above. 7. A silver halide color photographic light-sensitive material comprising a support having thereon a silver halide emulsion layer containing at least emulsion a and emulsion b defined by the following conditions. Emulsion a: containing silver halide grains and a dispersion medium, wherein the coefficient of variation of the particle size of all silver halide grains contained is 25% or less, and 50% or more of the total projected area of the silver halide grains is:
Tabular grains having an aspect ratio of 5 or more, and 30% or more (number ratio) of the tabular grains have dislocation lines in the central region and the peripheral region of the main plane, and one dislocation line in the peripheral region has one grain. 20 or more silver halide emulsions per emulsion. Emulsion b: tabular silver halide grains containing silver halide grains and a dispersion medium, wherein 50% or more of the total projected area of the contained silver halide grains is an aspect ratio of 3 or more, and the contained silver halide A silver halide emulsion wherein the average grain size of the grains is 1/2 or less of the average grain size of the silver halide grains of the emulsion a. 8. A silver halide color photographic light-sensitive material comprising a support having thereon a silver halide emulsion layer containing at least the emulsion a and the emulsion c defined by the following conditions. Emulsion c: a silver halide emulsion containing silver halide grains and a dispersion medium, wherein at least 50% of the total projected area of the contained silver halide grains is tabular silver halide grains having an aspect ratio of 2 or more and 5 or less. . 9. The silver halide color photographic light-sensitive material according to claim 7, wherein the emulsion a is the silver halide emulsion according to any one of claims 1 to 6.