JP2001142169A - Silver halide emulsion and silver halide photographic sensitive material using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silver halide emulsion containing flat platy silver halide grains having a specified silver iodide content and a layer structure by the control of growth characteristic using an inter-particle distance control method. SOLUTION: The silver halide emulsion contains flat platy silver halide particles obtained by particle growth in a direction perpendicular to the principal planes of base emulsion particles using an inter-particle distance controll method. The average silver iodide content of the regions from the principal planes of the flat platy silver halide particles to 5 nm depth in silver halide regions formed on the principal planes of the base emulsion particles is 3-15 mol%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide emulsion, and more particularly to a photographic silver halide emulsion having excellent sensitivity / fog ratio, excellent sensitivity / granularity, and improved storage stability and pressure resistance. About.

[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 is 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, 4,459,353, etc. disclose techniques using tabular silver halide grains, and improve sensitivity, including improvement in color sensitization efficiency by sensitizing dyes, and improve sensitivity and granularity. There are known advantages such as improvement in sharpness and covering power due to specific optical properties of tabular grains. However, it is not enough to meet recent high-level demands, and further improvement in performance is desired.

As an attempt to improve the photographic performance of tabular grains,
Attempts have been made to control the growth characteristics of tabular grains to form tabular grains having a unique layer structure. For example, JP-A-63-106746, JP-A-2-193138 and JP-A-5-66511 each disclose a tabular plate having a layer structure parallel to two main main planes of the tabular particles opposed to each other. Useful techniques relating to silver halide grains are disclosed. According to the description in JP-A-2-193138, by growing tabular grains as a host under high pBr conditions, the rate of lamination growth on the main plane with respect to the growth rate in the lateral direction is increased, and On the other hand, tabular grains having a parallel layer structure are obtained. However, high pB
The present inventors have found that growth of tabular grains at r causes problems such as a decrease in productivity due to a decrease in growth rate, and a decrease in sensitivity / fog ratio and sensitivity / granularity due to high fog. This has been confirmed in previous studies.

As another example, techniques relating to tabular grains having an annular layer structure are described in JP-A-8-254778 and JP-A-8-254779. These publications describe useful techniques for suppressing the growth of tabular grains on the main plane and forming an annular layer structure. However, this technique requires particle growth modifiers such as azaindoles, triaminopyrimidines, and polyiodophenols that suppress the growth of the main plane. In some cases, these grain growth modifiers may cause deterioration of photographic performance such as inhibition of spectral sensitization or poor desilverability. Or the need for a means of reducing or reducing the weight to form equivalent annular structured tabular grains.

The present inventors have also disclosed in Japanese Patent Laid-Open No. 2-1931
Based on the general knowledge in the art that tabular grain growth in the lateral direction is promoted under low pBr conditions as described in JP-A No. 38-38, a similar annular tabular plate is produced under extremely low pBr conditions. Attempts to form granular particles resulted in significant degradation of the particle size distribution. JP-A-9-179226 relates to a silver halide emulsion having a high iodine content surface layer having a surface exposed on the main plane of a tabular grain and a low iodine content surface layer formed therearound. The technology is described. However, this technique does not include any suggestion about the superiority in performance obtained by the layer structure formed by the layer growth on the main plane, and does not provide a specific means for achieving the same.

Japanese Patent Application Laid-Open No. 11-153841 discloses that when the silver iodide content of the outermost layer of tabular silver halide grains is I1 mol% in a main plane portion and I2 mol% in a side surface portion, I1>
A silver halide emulsion containing 50% or more (number) of tabular silver halide grains of I2 is disclosed. But,
Since the means for preparing the emulsion was within the category of conventionally known techniques, it encompasses the above-mentioned problems of the prior art and, in addition, by precisely embodying the unique layer structure intended by the present invention. It was also difficult to achieve the performance gains obtained. As described above, the present inventors have searched for a technique for forming tabular silver halide grains having a unique layer structure by a method other than conventionally known, such as pBr or a growth modifier.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to contain tabular silver halide grains having a layer structure having a specific silver iodide content by controlling growth characteristics using a grain-to-grain distance control method. The purpose is to provide a silver halide emulsion.

[0009]

The above object of the present invention is attained by the following constitutions.

(1) A silver halide emulsion containing tabular silver halide grains grown in a direction perpendicular to the main plane of the grains of a base emulsion grain by using a grain-to-grain distance control method. The average silver iodide content of the tabular silver halide grains in the region from the grain major plane to a depth of 5 nm in the silver halide areas formed on the grain major planes of the emulsion grains is 3 mol% or more and 15 mol% or less. A silver halide emulsion containing tabular silver halide grains of the formula:

(2) A silver halide emulsion containing tabular silver halide grains which are grown in the lateral direction of the base emulsion grains by using the intergrain distance control method, wherein the silver halide emulsion is formed from the side of the tabular silver halide. A silver halide emulsion containing tabular silver halide grains having an average silver iodide content of less than 5 mol% in a region up to a depth of 5 nm.

(3) Using a grain-to-grain distance control method, grains are grown in a direction perpendicular to the grain main plane of the base emulsion grains.
A silver halide emulsion further comprising tabular silver halide grains grown in the lateral direction of the base emulsion grains,
The average silver iodide content of the tabular silver halide grains in the region from the grain major plane to a depth of 5 nm in the silver halide area formed on the grain major plane of the base emulsion grains is 5 mol% to 15 mol. % Or less, and the average silver iodide content in a region from the side surface of the tabular silver halide to a depth of 5 nm is 5%.
Silver halide emulsion containing less than mol% of tabular silver halide grains.

(4) The average silver iodide content of the tabular silver halide grains in the region from the main plane to a depth of 5 nm is 5%.
4. The silver halide emulsion according to 1 or 3, which is at least 12 mol% and not more than 12 mol%.

(5) The silver halide emulsion as described in (2), (3) or (4), wherein the average silver iodide content in a region from the side surface of the tabular silver halide to a depth of 5 nm is less than 3 mol%.

(6) A silver halide emulsion containing tabular silver halide grains having a surface silver iodide content in a region along an edge of a main plane lower than that in a central region of the main plane.

7. The silver halide emulsion according to 6, wherein the silver halide grains are formed by a grain distance control method.

8. The silver halide emulsion according to any one of 1 to 7, wherein the tabular silver halide grains have an average of 10 or more dislocation lines per grain.

9. The silver halide emulsion according to any one of 1 to 8, wherein the average aspect ratio of the tabular silver halide grains is from 3 to 100.

(10) The silver halide emulsion as described in any of (1) to (9) above, wherein the coefficient of variation of the particle size of the tabular silver halide grains is 25% or less.

[11] A silver halide photographic light-sensitive material containing the silver halide emulsion according to any one of [11] to [10].

That is, the present inventors have disclosed Japanese Patent Application Laid-Open No. 10-33992.
By applying the equipment and production method capable of controlling the intergranular distance during the growth of silver halide grains disclosed in Japanese Patent Publication No. 3 to control the growth orientation of tabular grains, a layer structure horizontal to the main plane can be obtained. And a plate having an annular structure can be produced independently of the pBr conditions and the growth modifier, and furthermore, the silver iodide content of the layer structure can be precisely controlled by using the intergranular distance control method. Or by precisely controlling the silver iodide content distribution on the surface of the grains, the basic performance such as sensitivity / fog ratio, sensitivity / granularity, and also important performance requirements when using photographic light-sensitive materials The present invention has been found that storage stability and pressure resistance can be improved.

Hereinafter, each invention of the present application will be described in detail. In the present invention, control of the growth orientation of tabular grains,
Alternatively, the control of the growth characteristics means growth in which the thickness is laminated on the main plane of the tabular grains, that is, main plane growth, and growth in which the aspect ratio is increased without being laminated on the main plane, that is, without increasing the thickness, that is, That is, the ratio with the lateral growth is changed depending on the growth conditions. JP-A-2-1931
As described in No. 38 and the like, by pAg,
JP-A-8-254778 and JP-A-8-25477
With reference to the description in No. 9, this is possible with a surface modifier. The feature of the present invention with respect to such a conventionally known method is that the growth direction of the tabular grains is controlled by controlling the distance between grains.

In the present invention, the mechanism by which the effect is exhibited is not clear, but it has been experimentally obtained that the growth direction of tabular grains can be controlled by controlling the distance between grains. Specifically, by sufficiently increasing the inter-particle distance, the growth rate in the side direction of the flat plate increases, and conversely, by decreasing the inter-particle distance, the growth rate in the main plane direction increases. Moreover, unlike the control using the growth modifier or pBr, the total particle growth rate is not reduced. In the case of using a growth modifier, the growth rate of the main plane is suppressed, and in the case of growth with high pBr, the growth in the lateral direction is suppressed and the growth characteristics are controlled. Is easily expected, and has been confirmed by the present inventors' studies so far.

The silver halide emulsion defined by the present invention contains silver halide grains formed by using the intergranular distance control method. The method for controlling the distance between particles will be described below. In the present invention, the method of controlling the distance between grains refers to, in the step of forming silver halide grains, concentrating a reactant solution for forming grains to reduce the volume of the reactant solution, or an additive solution for forming grains. This method controls the average intergranular distance between silver halide grains in a reactant solution as defined below by concentrating and suppressing the increase in volume caused by the reaction.

Average distance between particles = [volume of reactant solution / number of grown particles in reactant solution] ^1/3 (hereinafter, when referred to as “interparticle distance” in this specification, this “average interparticle distance”
Shall be referred to. Specifically, the intergranular distance control method uses a device in which a concentration mechanism such as an ultrafiltration device is connected to a reaction vessel for forming silver halide grains, and water or water is used in the grain formation step. This is achieved by removing only the aqueous solution containing a soluble substance from the reaction solution. The concentrating mechanism is connected to the reaction vessel by a pipe or the like, and the reactant solution can be circulated at an arbitrary flow rate between the reaction vessel and the concentrating mechanism by a circulation mechanism for the reactant solution such as a pump, and can be arbitrarily stopped. Further comprising a device for detecting the volume of an aqueous solution containing a soluble substance extracted from the reaction solution by the concentration mechanism,
It is a facility equipped with a mechanism capable of arbitrarily controlling the amount. Further, other functions can be provided as necessary. Further, the apparatus for producing the silver halide emulsion of the present invention may be an apparatus having a mechanism for increasing the average intergranular distance by adding an aqueous solution containing water or a dispersion medium at a controlled temperature to a reaction vessel. preferable.

One embodiment of a silver halide emulsion production apparatus applicable to the production equipment of the present invention is that an average distance between grains in a grain growth process is arbitrarily controlled and maintained by an ultrafiltration apparatus and an aqueous solution addition line. An example of a possible apparatus for producing a silver halide emulsion will be described with reference to FIG.

The reaction vessel 1 initially contains a dispersion medium 3. The apparatus comprises a reaction vessel 1 and a silver addition line 4 for adding at least one aqueous solution of a silver salt, preferably an aqueous solution of silver nitrate, and at least one aqueous solution of a halide salt, preferably an alkali metal such as bromine, iodine or chlorine. It has a halide addition line 5 for adding an aqueous salt solution, an aqueous ammonium salt solution, or a mixture thereof. In addition, it has a stirring mechanism 2 for stirring the dispersion medium and the reactant solution (mixture of the dispersion medium and the silver halide grains) during the preparation of the silver halide emulsion. The stirring mechanism can be in any conventional manner. Silver salt aqueous solution is silver addition line 4
From the reaction vessel at a flow rate controlled by the silver addition valve 20. The halide aqueous solution is added to the reaction vessel from the halide addition line 5 at a flow rate controlled by the halide addition valve 21. The addition of the solution through the silver addition line 4 and the halide addition line 5 may be at the liquid level, but is more preferably performed in the liquid near the stirring mechanism 2. The stirring mechanism 2 mixes the aqueous silver salt solution and the aqueous halide salt solution with a dispersion medium, and enables the soluble silver salt to react with the soluble halide salt to produce silver halide.

During the first stage of silver halide formation, ie, during the nucleation step, a dispersion (reactant solution) containing the underlying silver halide nucleus grains is formed. Subsequently, the nucleation step is completed through an aging step as required. Thereafter, when the addition of the silver salt aqueous solution and the halogen salt aqueous solution is continued, the second stage silver halide formation, that is, the process proceeds to the growth process stage,
Additional silver halide produced as a reaction product in the process deposits on the initially formed silver halide nucleus grains, increasing the size of these grains. In the present invention, during the particle formation process by adding the aqueous silver salt solution and the aqueous halogen salt solution to the reaction vessel, a part of the reactant solution in the reaction vessel is sent to the ultrafiltration unit 12 through the liquid extraction line 8 by the circulation pump 13. It is sent and returned to the reaction vessel through the liquid return line 9. At this time, the pressure applied to the ultrafiltration unit 12 is adjusted by a pressure adjusting valve 18 provided in the middle of the liquid return line 9 so that a part of the aqueous solution containing a soluble substance contained in the reactant solution is subjected to the ultrafiltration. It is separated by a filtration unit and discharged out of the system through a permeated liquid discharge line 10. By such a method, it is possible to form grains while arbitrarily controlling the distance between grains even during the grain growth process by adding the aqueous silver salt solution and the aqueous halide solution to the reaction vessel.

When this method is applied in the present invention, it is preferable to arbitrarily control the permeate amount (ultrafiltration flux) of the aqueous solution containing the soluble matter separated by the ultrafiltration membrane. For example, in such a case, the ultrafiltration flux can be arbitrarily controlled using the flow control valve 19 provided in the middle of the permeate discharge line 10. At this time, in order to minimize pressure fluctuations in the ultrafiltration unit 12, a valve 2 provided in the middle of the permeated liquid return line 11
5, the permeate return line 11 may be used.
Alternatively, the valve 25 may be closed and the permeate return line 11 may not be used, which can be arbitrarily selected according to the operating conditions. For detecting the ultrafiltration flux, a flow meter 1 provided in the middle of the permeated liquid discharge line 10 is used.
4 may be used, or may be detected by weight change using the permeated liquid receiving container 27 and the scale 28.

Preferably, the circulation flow rate through the ultrafiltration step is sufficiently high. Specifically, the residence time of the silver halide reactant solution in the ultrafiltration unit including the liquid take-out line and the liquid return line is preferably within 30 seconds, more preferably within 15 seconds, and further preferably within 10 seconds. Particularly preferred. The volume of the ultrafiltration step including the liquid take-out line 8, the liquid return line 9, the ultrafiltration unit 12, the circulation pump 13, and the like is 30 times the volume of the reaction vessel.
% Or less, more preferably 20% or less, and particularly preferably 10% or less.

As described above, by applying the ultrafiltration step, the distance between particles can be arbitrarily reduced even during the particle growth process. Further, by adding water or an aqueous solution containing a dispersion medium or the like whose temperature is controlled from the addition line 7, the distance between the particles can be arbitrarily increased even in the particle growth process.

In the present invention, there are no particular restrictions on the ultrafiltration module and the circulating pump that can be used in carrying out the ultrafiltration, but the ultrafiltration module and the circulating pump may act on the silver halide emulsion to adversely affect photographic performance and the like. It is preferable to avoid any material and structure. In addition, the molecular weight cutoff of the ultrafiltration membrane used in the ultrafiltration module can be arbitrarily selected. For example, when it is desired to remove a dispersion medium such as gelatin contained in a silver halide emulsion or a compound used in preparing an emulsion during the grain growth process, an ultrafiltration membrane having a molecular weight cut-off greater than the molecular weight of the object to be removed is selected. Can also
If removal is not desired, an ultrafiltration membrane having a molecular weight cut off less than the molecular weight of the object to be removed can be selected.

In the present invention, the use of the inter-grain distance control method for grain formation or the application of the inter-grain distance control method during grain formation means that (1) the above-described concentration mechanism is used in the step of forming silver halide grains. To reduce the volume of the reactant solution. (2) In the step of forming silver halide grains, using the above-mentioned concentration mechanism, an aqueous solution containing water or a soluble substance in the same amount as the amount of the added liquid for silver halide formation is removed from the reactant solution, Keep the volume of the solution constant. (3) In the step of forming silver halide grains, by using the above-mentioned concentration mechanism, at the same time as adding an additive solution for forming silver halide, an aqueous solution containing water or a soluble substance is removed from the reaction solution, and Suppress volume increase of solution. The above operations (1) to (3) or combinations thereof are meant. In (3), the volume of the reactant solution may increase or decrease as a result of suppressing the volume increase. In the present invention, the above (1) to (1)
The following operation (4) is preferably used in combination with (3). (4) Add water or an aqueous solution containing a soluble substance to increase the volume of the reaction solution.

For example, in the present invention, when it is desired to form particles with a sufficiently large interparticle distance, the volume of the reactant solution is increased up to the upper limit volume of the reaction vessel at a certain stage of the particle formation, and then the particles are formed. By removing the volume of the solution amount to be added by the concentration mechanism, it is possible to form particles while maintaining a sufficiently large interparticle distance without overflowing from the reaction vessel. In addition, when it is desired to form particles with a sufficiently small distance between particles, the volume of the reactant solution is reduced at a certain stage of particle formation by using a concentration mechanism, and then the volume of the solution amount added for particle formation is reduced. By removing the particles by a concentration mechanism, particles can be formed while maintaining a small distance between particles.

In general, the step of forming grains in a silver halide emulsion is roughly classified into a nucleation step (consisting of a nucleation step and a nucleation step) and a subsequent step of growing the nuclei. Also,
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. In the present invention, the intergranular distance control method is preferably applied to a step of growing silver halide grains. In the present invention, the interparticle distance control method does not necessarily need to be applied over the entire particle formation process. Rather, it is preferably used in the part of the particle forming step other than the nucleus forming step. However, once the circulation of the reactant liquid between the concentration mechanism and the reaction vessel is started, it is preferable to continue the circulation until the end of the particle formation. In the present invention, between a concentration mechanism such as an ultrafiltration device and a reaction vessel, in a state in which the emulsion is circulated and water or an aqueous solution containing a soluble substance is not removed, the interparticle distance control method is applied. Is not specified.

The silver halide emulsion of the present invention contains tabular grains. Tabular grains are crystallographically classified as twins. Twins are silver halide crystals having one or more twin planes in one grain, and the classification of twins is based on a report by Klein and Moiser in Photographie Corspondents (Photographihose Ko).
rrespondenz) Vol. 99, p100, ibid.
00, p57.

The tabular grains in the present invention preferably 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 tabular grains to be contained are substantially parallel to the main plane, to prepare a sample. This was cut using a diamond cutter to a thickness of 0.1 mm.
Obtain a thin section of about 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 the above-mentioned transmission electron microscope and showing tabular grains having a cross section substantially perpendicular to the main plane. Are arbitrarily selected, and the distance between the two twin planes having the shortest distance among the even twin planes parallel to the main plane is obtained for each grain and averaged. In the present invention, the distance between twin planes is
Factors affecting the supersaturation state during nucleation, such as gelatin concentration, gelatin species, temperature, iodine ion concentration, pB
It can be controlled by appropriately selecting combinations of various factors such as r, pH, ion supply speed, and stirring rotation speed. 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,
Alternatively, the description in JP-A-1-213637 can be referred to. In the present invention, the average distance between twin planes is preferably 0.005 μm to 0.05 μm, and more preferably 0.01 μm to 0.02 μm.

The structure of the tabular grains specified in the present invention will be described below. The silver halide grains related to the present invention may have portions other than the specified structures.

The term "base emulsion" as used herein means a tabular silver halide emulsion, which is from 20% to 99%, preferably from 50% to 9%, based on the silver halide emulsion after completion of grain growth.
It has a silver content ratio of 5% or less. Various characteristics of the base emulsion can be arbitrarily selected according to various characteristics required for the silver halide emulsion of the present invention after completion of grain growth. For example,
The average aspect ratio of the base emulsion is preferably from 3 to 100, and more preferably from 5 to 50. The silver halide composition of the base emulsion is preferably silver bromide, silver iodobromide or silver chloroiodobromide having a silver iodide content of 15 mol% or less. The base emulsion preferably contains tabular silver halide grains having dislocation lines. The base emulsion can be prepared by using a known technique for preparing a tabular silver halide emulsion.

Tabular silver halide grains grown in a direction perpendicular to the main plane of the grain of the base emulsion grains are referred to as those having a main plane grown on the main plane of the base emulsion grains and side growth of the base emulsion grains. Refers to tabular silver halide grains formed with little or no activity. Specifically, it refers to tabular silver halide grains as exemplified in FIG. The silver halide region formed on the main plane of the base emulsion grain refers to a silver halide region formed when the main plane is grown on the main plane of the base emulsion grain. This is the portion shown in (1) of (a) and (3) of FIG. 2 (c). The region from the main plane of the tabular silver halide grains to a depth of 5 nm in the silver halide area formed on the main plane of the base emulsion grain is defined as the silver halide area formed on the main plane of the base emulsion grain. Among them, it refers to a region divided by a main plane and a plane perpendicular to the main plane and parallel to the main plane at a point 5 nm in an inward direction. The average silver iodide content in the region from the main plane of the tabular silver halide grains to a depth of 5 nm is from 3 mol% to 1 mol%.
It is at most 5 mol%, preferably at least 5 mol% and at most 12 mol%. The ratio of the silver halide regions formed on the main plane of the base emulsion grains in the whole grains is preferably 5% or more and 50% or less, more preferably 10% or more and 35% or less. Further, as for the relationship between the layer and an adjacent layer, it is preferable that one of the following conditions (1) to (3) is satisfied. (1) The composition ratio of one or more halides of silver halide forming a layer differs by 1 mol% or more, preferably 3 mol% or more. (2) There is a difference of 1:10 or more, preferably 1:20 or more, in the content of the dopant (the dopant will be described later) contained in the layer. (3) In the content of the reduction sensitization nucleus contained in the layer,
There is a difference of 1:10 or more, preferably 1:20 or more.

Tabular silver halide grains grown in the lateral direction of the base emulsion grains are those in which the side faces of the base emulsion grains are grown, and the main plane growth of the base emulsion grains on the main plane is hardly performed, or is not performed at all. Refers to tabular silver halide grains formed without performing the above steps. Specifically, it refers to tabular silver halide grains having a ring structure as illustrated in FIG. 2 (b). 5n depth from side of tabular silver halide grains
The region up to m refers to a region divided by the side surface and a plane parallel to the side surface at a point 5 nm inward and perpendicular to the side surface. The average silver iodide content in the region from the side surface of the tabular silver halide grains to a depth of 5 nm is less than 5 mol%, preferably less than 3 mol%. The ratio of the region formed by the lateral growth to the entire grain is 1% or more in terms of the silver amount ratio.
It is preferably 0% or less, more preferably 2% or more and 15% or less, and still more preferably 3% or more and 10% or less. In addition, also in this case, the above (1) to (1)
It is preferable to satisfy any one of the conditions (3).

Tabular silver halide grains grown in the direction perpendicular to the main plane of the grains of the base emulsion grains and further grown in the side direction of the base emulsion grains are referred to as the tabular silver halide grains on the main plane of the base emulsion grains. After performing main plane growth and performing side growth of the base emulsion grains with little or no growth, perform side growth of the base emulsion grains and hardly perform main plane growth on the main plane, or Refers to tabular silver halide grains grown without any treatment. Specifically, it refers to tabular silver halide grains as exemplified in FIG. 2 (c).

In the present invention, the average silver iodide content in the region from the main plane of the tabular silver halide grains to a depth of 5 nm, and the depth of 5 nm from the side surfaces of the tabular silver halide grains.
The average silver iodide content in the region up to 、 was determined by pretreating the grains in an ultramicrotome into ultrathin sections of about 60 nm thickness and analyzing them with an analytical electron microscope (EDX).
v X-ray Spectroscopy: Also referred to as energy dispersive X-ray spectroscopy, EDS. ) Determined by performing an analysis.

As methods for determining the halogen composition distribution inside the emulsion grains, there are known measurement methods such as X-ray diffraction, XMA (also referred to as X-ray microanalyzer, EOMA), and electron microscope. However, the information obtained by X-ray diffraction is an average value of a large number of grains, and it is not possible to obtain information on a halogen composition localized portion such as a particularly high silver iodide content. Further, XMA as disclosed in JP-A-58-113927, spot analysis with an electron microscope,
Direct observation with a dialysis electron microscope at a low temperature disclosed in Japanese Patent Application Laid-Open No. 1-183645 could not determine the change in the composition of the particles in the thickness direction. The problem is that the tabular silver halide grains are produced with an ultramicrotome having a thickness of about 60 mm.
This problem can be solved by pretreating ultra-thin sections of nm and performing EDX analysis with an analytical electron microscope to three-dimensionally measure the halogen composition inside the grains.

An analytical electron microscope (ATEM: Analytical Transmission) used for the analysis of ultrathin sections.
ion Electron Microscope)
In order to analyze a minute part, a device which can make an electron beam probe as thin as possible is preferable. Furthermore, an apparatus that can obtain a high probe current even when the electron beam probe is narrowed down is more preferable so that a spectrum with good S / N can be obtained at the time of EDX analysis. Most preferred is an electron beam probe diameter of 1n.
Field emission type transmission electron microscope (FE-T) having a field emission type electron source capable of obtaining a probe current of 0.5 nA or more at m
EM). Note that, since the transmittance increases as the acceleration voltage of the electron microscope increases, it is preferably 200 kV or more.

The procedure for analyzing the halogen composition distribution of the tabular silver halide grains is as follows. In order to remove silver halide particles from the silver halide emulsion used for the measurement, a method is generally used in which gelatin, which is a dispersion medium, is decomposed with a protease under safelight, and the supernatant is removed by centrifugation and washed with distilled water. Used. When silver halide particles are present in a coating film containing gelatin as a main binder, gelatin may be similarly decomposed by a protease and the silver halide particles may be taken out. In this case, the polymer may be dissolved and removed using an appropriate organic solvent. Further, when a dye, a sensitizing dye, or the like is adsorbed on the grain surface, an alkaline aqueous solution, alcohol or the like is appropriately used to remove these, and a clean silver halide grain surface can be obtained.

The extracted silver halide grains were analyzed as follows: “Analysis of halogen distribution in silver halide grains by analytical electron microscope—
(III) ”Inoue, Nagasawa: Abstracts of the Photographic Society of Japan 1987 Annual Meeting (1987) p. According to the method described in 46, embedded in an epoxy-embedded resin for electron microscope observation pretreatment, and using an ultramicrotome equipped with a diamond knife,
An ultra-thin section having a thickness of about 60 nm is prepared. The ultra-thin section is collected on a grid mesh for electron microscopic observation and then attached to a liquid nitrogen cooling holder and inserted into an electron microscope to prevent electron beam damage during observation and analysis.

In the analysis, after confirming the analysis position on a transmission electron microscope image, spot analysis is performed with a finely narrowed electron beam probe. The analysis time is preferably 50 seconds or more in order to obtain an EDX spectrum with a good S / N. After the background is removed from the obtained EDX spectrum by a computer for EDX data processing, quantitative calculation is performed. At this time, since the ultrathin section is a thin film sample having a thickness of about 60 nm, the obtained EDX spectrum can be handled by the thin film approximation method ignoring the X-ray absorption and fluorescence excitation effects in the sample. For the quantitative calculation, the peak intensity of BrKα and ILα is used, and the silver iodide content is calculated by a computer for EDX data processing.

The specific method for measuring the average silver iodide content in the region from the main plane of the tabular silver halide grains to a depth of 5 nm is as follows. From the continuous section samples, a section sample having the largest grain cross-sectional area is selected from the continuous sections of tabular silver halide grains having a section perpendicular to the main plane. The silver iodide content in a region from the two main planes of the tabular silver halide grains to a depth of 5 nm in the section sample was measured at 10 points or more at equal intervals in the width direction of the main plane. The average value is defined as the average silver iodide content in a region from the main plane of the tabular silver halide grains to 5 nm. Similarly, the silver iodide content in the region from the two side surfaces of the tabular silver halide grain to a depth of 5 nm is measured at five or more points at equal intervals in the width (grain thickness) direction of the side surface. The average value of the values is defined as the average silver iodide content in a region from the side surface of the tabular silver halide grains to a depth of 5 nm.

When a silver halide region is formed on the main plane of the base emulsion grains by using the intergrain distance control method, at least 50%, preferably 70%, of the silver content in the region.
As described above, it is necessary to grow particles while maintaining the distance between particles at 2.6 μm or less, more preferably over 90%. Preferably, the distance between particles is 2.3 μm or less, more preferably 2.0 μm or less, and still more preferably 1.5 μm.
m, particularly preferably 1.0 μm or less. Specifically, in the particle growth step, a method of concentrating the volume in the reaction vessel using a concentrating mechanism and then forming a layer is preferably used. It is also preferable to further apply the interparticle distance control method during the formation of the region.

When particles are grown in the lateral direction by using the inter-particle distance control method, at least 50% or more, preferably 70% or more, more preferably 9% or more of the silver content of the layer forming portion.
It is necessary to grow while maintaining the distance between particles at 3.0 μm or more over 0% or more. Preferably the distance between the particles is at least 3.5 μm, more preferably at least 4.0 μm,
More preferably 4.5 μm or more, particularly preferably 5.
0 μm or more. Specifically, in the particle growth process,
After increasing the volume of the reaction solution by adding an aqueous solution containing water or a soluble substance to near the upper limit of the reaction vessel, the lateral growth is started, and the lateral direction is increased while applying the interparticle distance control method using a concentration mechanism. A method of growing is preferably used.

In the silver halide emulsion of the present invention, when growing in the lateral direction, generally known grain growth modifiers can be used. Is preferably used in combination with the interparticle distance control method, and more preferably, an annular layer structure is formed by an interparticle distance control method without using a particle growth modifier. Examples of the grain growth modifier include U.S. Patent Nos. 4,400,463, 4,804,621, 4,713,323, 5,035,992, 5,183,732, Nos. 5,178,998, JP-A-8-254778, JP-A-8-254779, and JP-A-8-254780 can be used.

The distribution of the silver iodide content in the main plane of the tabular silver halide grains specified in the present invention will be described below. The area along the edge in the main plane as referred to in the present invention is, as shown in FIG. 3, 10% of the ridge side having a diameter connecting the center of the main plane with the ridge forming the boundary between the main plane and the side face.
(A ₁ ), and the central area in the main plane refers to the area (A ₂ ) inside the area.

The phrase that the surface silver iodide content in the region along the edge in the main plane of the tabular silver halide grains is lower than the surface silver iodide content in the central region of the main plane means that the surface in the region (A ₁ ) When the silver iodide content is I ₁ mol% and the surface silver iodide content in the region (A ₂ ) is I ₂ mol%, I ₁ <
Means in the I ₂ the relationship. Preferably an I ₂ -I ₁ ≧ 1.5 mol% in the present invention, I ₂ -
More preferably, I ₁ ≧ 3 mol%, and I ₂ −I ₁ ≧
The case of 5 mol% is particularly preferred. In the present invention, I ₁
And I ₂ are determined by measuring the average silver iodide content of A ₁ and A ₂ by EDX analysis with an analytical microscope using the above-mentioned serial section sample.

The average silver iodide content of the silver halide emulsion of the present invention is preferably 15 mol% or less, more preferably 1 mol% or more and 10 mol% or less. The halide composition of the silver halide grains contained in the silver halide emulsion of the present invention is particularly limited except for the silver iodide content of the layer structure or the distribution of the silver iodide content on the surface defined by the present invention. Although not particularly preferred, silver iodobromide or silver chloroiodobromide mainly composed of silver bromide is preferred.

The silver iodide content of each silver halide grain was determined by the EPMA method (Electron Probe Mic).
It can be determined by using the Ro Analyzer method. In 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 a portion to be analyzed can be performed by X-ray analysis by 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 (average value as one grain) of each grain can be determined. When the silver iodide content of at least 50 grains is determined by the EPMA method, the average of these is used to determine the average silver iodide content of the silver halide emulsion. The average silver iodide content was measured by X-ray fluorescence analysis, ICP (induction plasma) emission analysis,
It can also be determined by measuring the silver iodide content of the whole emulsion by another well-known method such as P mass spectrometry. In the tabular grains of the present invention, the average silver iodide content of each tabular grain is preferably more uniform among grains. When the distribution of silver iodide content among grains was measured by the EPMA method, the relative standard deviation (= standard deviation of silver iodide content / average of silver iodide content) was 30%.
Hereinafter, it is more preferable that it is 20% or less.

The average silver halide composition on the entire surface of the silver halide grains was determined by an XPS method (X-ray Photoel).
electron spectroscopy (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 MgKα was irradiated as a probe X-ray at an X-ray source voltage of 15 kV and an X-ray source current of 40 mA. 3
The measurement is performed on electrons of d5 ^{/ 2} , Br: 3d, and I: 3d3 ^{/ 2} . The integrated intensity of the measured peak is used as the sensitivity factor (Sens
The intensity is corrected by an intensity factor, and the silver halide composition on the surface of the silver halide grain is determined from these intensity ratios. The average silver iodide content on the surface of silver halide grains in the silver halide emulsion of the present invention is preferably 15 mol% or less, more preferably 3 mol% to 15 mol%, and further preferably 5 mol%. Not less than 12 mol%.

The silver halide emulsion of the present invention preferably contains tabular grains having dislocation lines. Dislocation lines of silver halide grains are described, for example, in J. Am. F. Hamilto
n, Photo. Sci. Eng. 11 (1967) 5
7, T. Shiozawa, J .; Soc. Photo.
Sci. Japan 35 (1972) 213,
It 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 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. When it is not possible to count the number of dislocation lines per particle, such as when the dislocation lines exist densely or when the dislocation lines intersect with each other, it is counted that there are many dislocation lines. Many of the dislocation lines existing in the central region of the main plane of the 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 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 tabular silver halide grains of the present invention, the radially extending dislocation lines present in the outer peripheral region are averaged by 1 per grain.
It is preferable to have 0 or more dislocation lines in the outer peripheral region per particle on average, and more preferably to have at least one dislocation line in the central region of the main plane. Also,
In the tabular grains contained in the emulsion of the present invention, tabular grains having such dislocation lines are preferably present in an amount of 50% or more (number ratio), more preferably 80% or more.

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.

The iodide ion releasing agent is a compound represented by the general formula [RI], which releases iodide ions by reaction with a base or a nucleophile. R represents a monovalent organic group. R represents an alkyl group, an alkenyl group,
Alkynyl group, aryl group, aralkyl group, heterocyclic group,
It is preferably an acyl group, a carbamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group. R is preferably an organic group having 30 or less carbon atoms, more preferably 20 or less, and 10 or less.
It is more preferred that: R preferably has a substituent, and the substituent may be further substituted with another substituent. Preferred substituents include halide, alkyl, alkenyl, alkynyl, aryl, aralkyl, heterocyclic, acyl, acyloxy, carbamoyl, alkyloxycarbonyl, aryloxycarbonyl, alkylsulfonyl, Arylsulfonyl group, sulfamoyl group, alkoxy group, aryloxy group, amino group, acylamino group, ureido group, urethane group, sulfonylamino group, sulfinyl group, phosphoric amide group, alkylthio group, arylthio group, cyano group, sulfo group, Examples include a carboxyl group, a hydroxy group, and a nitro group. As the iodide ion releasing agent RI, iodoalkanes, iodoalcohols, iodocarboxylic acids, iodoamides and derivatives thereof are preferable, and iodoamides, iodoalcohols and derivatives thereof are more preferable, and iodoamides substituted with a heterocyclic group. Is more preferable, and the most preferable example is (iodoacetamido) benzenesulfonate.

Specific examples of the iodine ion releasing agent that can be preferably used are shown below.

[0063]

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When an iodide ion releasing agent is reacted with a nucleophile to release iodide ions, hydroxide ions, sulfite ions, thiosulfate ions, sulfinates, carboxylates, ammonia, Amines, alcohols, ureas, thioureas, phenols, hydrazines, sulfides, hydroxamic acids, and the like can be used, and hydroxide ions, sulfite ions, thiosulfate ions, sulfinates, carboxylate salts can be used. ,ammonia,
Amines are preferred, and hydroxide ions and sulfite ions are more preferred.

The preferred reaction conditions for introducing dislocation lines into the silver halide emulsion of the present invention with an iodine ion releasing agent are as follows: a reaction temperature is preferably 70 ° C. to 30 ° C., and more preferably 65 ° C. to 35 ° C. Is more preferable. pB
r is preferably 1.50 or less, more preferably 1.30 or less, and even more preferably 1.10 or less. The amount of the iodine ion releasing agent to be added is 0.5 to 0.5 with respect to the total amount of silver halide after completion of grain growth.
It is preferably 3.0 mol%. In the case where hydroxide ions are used as nucleophiles at the time of iodine ion releasing reaction, that is, when the iodide ion releasing agent is reacted by adjusting the pH, the reaction is carried out at a pH of 9.0 or more and 12.0 or less. The pH is preferably 9.5 or more and 11.0 or less. When a thing other than hydroxide ion is used as the nucleophile, the amount of the nucleophile is preferably 0.25 times or more and 2.0 times or less, more preferably 0.50 times or more the amount of the iodide ion releasing agent. It is more preferably 1.5 times or less, and more preferably 0.80 times or more and 1.2 times or less. When the nucleophile is other than hydroxide ion, the pH at the time of the iodine ion release reaction is 6.0 or more and 11.1.
It is preferably 0 or less, more preferably 7.0 or more and 10.0 or less.

Preferred reaction conditions when dislocation lines are introduced into the silver halide emulsion of the present invention by a fine grain emulsion containing silver iodide are shown below. The temperature at which the fine grain emulsion containing silver iodide is added is preferably 70 ° C to 30 ° C.
More preferably, the temperature is from 5C to 35C. pBr is 1.
It is preferably at most 50, more preferably at most 1.30, even more preferably at most 1.10. The amount of the fine grain emulsion containing silver iodide to be added is preferably 0.5 to 3.5 mol% in terms of silver iodide, based on the total silver halide after grain growth.

In the present invention, the aspect ratio of tabular grains refers to the ratio of the grain size to the grain thickness (aspect ratio = grain size / thickness). Here, the particle diameter means the diameter of a circle having an area equal to the area when the grain is projected perpendicular to the main plane of the tabular grain. The grain size, grain thickness, and aspect ratio of the silver halide grains can be determined by the following methods. A sample was prepared by coating a latex ball with a known particle size as an internal standard on a support, and silver halide particles so that the main plane was oriented parallel to the substrate. After that, a replica sample is prepared by a normal replica method. An electron micrograph of the sample is taken, and the projected area and thickness of each particle are determined using an image processing device or the like. In this case, the projected area of the particle can be calculated from the projected area of the internal standard, and the thickness of the particle can be calculated from the internal standard and the length of the shadow of the particle. The particle size can be calculated from the obtained projected area of each particle, and the aspect ratio of each particle can be calculated from the particle size and the thickness according to the above formula.

In the silver halide emulsion of the present invention, the tabular silver halide grains contained in the emulsion have an average aspect ratio of 3
It is preferably at least 100 and at most 100, and more preferably at least 5 and at most 50 in average aspect ratio. Here, the average aspect ratio means an arithmetic average value obtained by measuring the aspect ratio of 500 or more tabular silver halide grains contained in the silver halide emulsion by the above-mentioned replica method.

In the present invention, the coefficient of variation of the grain size is a value defined by the following. When 500 or more tabular silver halide grains contained in a silver halide emulsion are measured by the replica method described above, It calculates using the value obtained by the above.

Coefficient of variation of grain size [%] = (standard deviation of grain size / average of grain size) × 100 The variation coefficient of the grain size of tabular silver halide grains contained in the silver halide emulsion of the present invention is as follows: 2
It is preferably at most 5%, more preferably at most 20%, even more preferably at most 16%. The average particle size is preferably from 0.1 to 5.0 μm, and more preferably from 0.5 to 3.0 μm. US Patent No. 4,74
No. 8,106, the particle size is 0.6 μm.
m or less, which can contribute to higher image quality.

The average thickness of the tabular silver halide grains contained in the silver halide emulsion of the present invention is from 0.05 μm to 1.0 μm.
5 μm is preferred, and more preferably 0.07 μm to 0.1 μm.
50 μm. By limiting the thickness of the tabular grains to 0.5 μm or less, more preferably 0.3 μm or less, the sharpness can be improved.

The silver halide emulsion of the present invention may contain silver halide grains having an epitaxial growth phase (hereinafter referred to as epitaxial grains). Epitaxial growth means that different crystals are bonded and grown on the crystal plane of a certain crystal, as generally accepted in the field of silver halide emulsions and the field of semiconductor crystal growth. In the present invention, in particular, it means that a silver salt crystal having a composition different from that of the host is grown as a guest on the surface of a silver halide grain serving as a host. The epitaxial growth phase refers to a silver salt crystal layer grown by the above-described epitaxial growth.

The epitaxial growth phase is preferably silver halide having a halide composition different from that of the junction of silver halide grains serving as a host. When the junction with the epitaxial growth phase of the host grains is mainly composed of silver bromide, the epitaxial growth phase is preferably mainly composed of silver chloride. It is preferable that the epitaxial growth phase is mainly composed of silver bromide. Here, “mainly composed of silver chloride” means that the silver chloride content is 60 mol% or more, preferably 70 mol% or more, and more preferably 80 mol%. Similarly, being mainly composed of silver bromide means that the silver bromide content is 60 mol% or more, preferably 70 mol% or more, and more preferably 80 mol%.

The epitaxial growth phase preferably accounts for 0.5 to 30 mol%, more preferably 1 to 20 mol%, and more preferably 3 to 20 mol%, of silver, based on the whole grains.
More preferably, it occupies 15%. The epitaxial growth phase has an area ratio of 1 to 4 with respect to the projected area of the grains.
It preferably occupies 0%, more preferably occupies 3 to 30%, and even more preferably occupies 5 to 20%. The epitaxial growth phase may be present on one crystal plane of the host particle, or may extend over a plurality of crystal planes.However, the epitaxial growth phase exists near the apex, near the ridgeline, or at the center of the crystal plane of the host particle. Is preferable, and it is particularly preferable that the compound exists near a vertex or a ridge line.

The silver halide emulsion of the present invention may contain a polyvalent metal compound as a dopant.
In particular, it is preferable to contain tabular grains having a layer structure in which the content ratio of the polyvalent metal compound is different. Further, a dopant may be contained separately from the layer structure defined in the present invention. Here, “doping” or “doping” indicates that a substance other than silver ions or halide ions is contained in silver halide grains, and the term “dopant” is used.
Represents a compound doped into silver halide grains. The term "metal dopant" refers to a polyvalent metal compound that dopes the silver halide grains.

In the present invention, the particles are 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. Also,
The metal compound to be doped is selected from a single salt or a metal complex.
Preferably. When selecting from metal complexes, 6
Pentahedral, five-coordinate, four-coordinate, and two-coordinate complexes are preferred.
Coordinated, planar four-coordinated complexes are more preferred. The complex is mononuclear
It may be a complex or a polynuclear complex. In addition, complex
The ligand to be formed is CN^-, CO, NO_Two ^-, 1,1
0-phenanthroline, 2,2'-bipyridine, S
O_Three ^-, Ethylenediamine, NH_Three, Pyridine, H_TwoO, N
CS^-, CO, NO_Three ^-, SO_Four ^2-, OH^-, N_Three ^-, S_Two ^-,
F^-, Cl^-, Br^-, I^-Etc. can be used. Special
K is a preferred metal dopant for_FourFe (C
N)₆, K_ThreeFe (CN)₆, K_FourFe (CN)₆, Pb
(NO_Three)_Two, K _TwoIrCl₆, K_ThreeIrCl₆, K_TwoIrB
r₆, InCl_ThreeIs raised. Other than metal dopant
As dopants, sulfide ions and selenium described below are used.
Using chalcogen anions such as ion and tellurium ion
Can be.

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 pre-treated as follows. First, add 0.2 ml to about 30 ml of emulsion.
% Actinase aqueous solution (50 ml) is added, and the mixture is stirred at 40 ° C. for 30 minutes to perform gelatin decomposition. This operation is repeated five times. After centrifugation, washing is repeated 5 times with 50 ml of methanol, 2 times with 50 ml of 1N nitric acid, and 5 times with ultrapure water. 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) High frequency induction plasma emission spectrometer (I
CP-AES) or atomic absorption. From the difference between the amount of metal contained in silver halide after surface melting and the total amount of silver halide metal not dissolved,
The amount of metal per mole of silver halide present on about 3% of the grain surface can be determined. As a method for determining the metal, an aqueous solution of ammonium thiosulfate, an aqueous solution of sodium thiosulfate, or an aqueous solution of potassium cyanide is used.
Matrix-matched ICP-MS method, ICP-
An AES method or an atomic absorption method can be used. Among them, potassium cyanide as a solvent and ICP- as an analyzer
MS (FISON Elemental Analysis)
is manufactured), about 40 mg of silver halide is dissolved in 5 ml of 0.2N potassium cyanide, and then 10 pp.
The internal standard element Cs solution was added so as to obtain b, and the volume was adjusted to 100 ml with ultrapure water to obtain a measurement sample. Then, the metal in the measurement sample is quantified by ICP-MS using a calibration curve obtained by combining a matrix with silver halide containing no metal dopant. 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 amount of the dopant can be quantified. By combining the above-mentioned metal dopant quantification method with well-known particle observation using an electron microscope, it is possible to determine the metal dopant doped in a specific region of the tabular grains. The preferred content of the metal dopant in the tabular grains of the present invention is 1 silver halide.
It is 1 × 10 ^-9 mol to 1 × 10 ^-4 mol, more preferably 1 × 10 ^-8 mol to 1 × 10 ^-5 mol per mol.

In the present invention, it is preferable to add a metal dopant to the base grains in a state where the metal dopant has been 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 × 10 ^−1.
Mol to 1 × 10 ⁻⁷ mol, preferably 1 × 10 ⁻³ mol to 1 mol
× 10 ^-5 mol is more preferred. As a method of doping a metal halide into silver halide fine particles 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 that the composition has the same main halide as the main halide constituting the base particles (the halide contained at the highest molar ratio). Physical ripening conditions for depositing silver halide fine grains can be arbitrarily selected from 30 ° C. to 70 ° C./10 minutes to 60 minutes.

The silver halide emulsion of the present invention can be preferably used by performing reduction sensitization treatment (hereinafter simply referred to as reduction sensitization) during grain formation. Reduction sensitization is performed by adding a reducing agent to a silver halide emulsion or a mixed solution for grain growth. Alternatively, it is carried out by ripening or growing a silver halide emulsion or a mixed solution for grain growth under a low pAg of 7 or less, or 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 per mole of silver halide.
^-2 to 10 ^-8 mol is preferable, and 10 ^-4 to 10 ^-6 mol is more preferable.

To carry out 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.
~ 3.

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.

The reduction sensitizer, the silver salt and the alkaline compound for the reduction sensitization may be added instantaneously or 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. Prior to adding the soluble silver salt and / or soluble halide into 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.

The silver halide emulsion of the present invention has, as a preferred embodiment, a layer containing a nucleus containing a chalcogenide silver in the grains. In that case, it is more preferable that the silver halide emulsion has been subjected to a reduction sensitization treatment. The silver chalcogenide nucleus-containing layer is preferably outside 50%, more preferably outside 60% by volume of the whole grains. The silver chalcogenide nucleus containing layer may or may not be in contact with the grain surface. Silver chalcogenide nuclei are formed by addition of 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 (e.g., allyl isoselenocyanate, etc.), selenoureas (e.g., 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.), and selenophosphates (eg, tri-p-triselenophosphate, etc.) And selenides (for example, 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 (eg, tributylphosphine telluride, tricyclohexylphosphine telluride, triisopropylphosphine telluride, etc.), telluroamides (eg, 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 SM [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 different even if they are the same. 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.

[0089] Formula (1) compounds represented by - [3] may be a polymer containing as a repeating unit a divalent group derived from these structures, 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.

The substituents for R, R ₁ and R ₂ include an alkyl group (for example, methyl, ethyl, hexyl), an alkoxy group (for example, 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.

The divalent linking group represented by L includes 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,

[0096]

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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.

[0100]

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Specific examples of the compounds represented by the formulas [1] to [3] are described, for example, in 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 1 mol of silver halide.
^-3 to 10 ^-6 is more preferable. As a method for adding a compound capable of releasing a chalcogen ion for forming a silver chalcogenide nucleus, a method of adding the compound instantaneously or a method of adding 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. 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 silver chalcogenide nuclei formed on the same surface as the chemical sensitization do not substantially contribute to the effects of the present invention.

The silver halide emulsion of the present invention is produced in the presence of a dispersion medium, that is, in a solution containing the dispersion medium. here,
The aqueous solution containing a dispersion medium refers to an aqueous solution in which a protective colloid is formed in an aqueous solution by gelatin or another substance capable of constituting a hydrophilic colloid (a substance capable of serving as a binder), and preferably contains a colloidal protective gelatin. Solution. When gelatin is used as the protective colloid in the grain forming step of the silver halide emulsion of the present invention, 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). In the case of gelatin, it is preferable to use those having a jelly strength of 200 or more in the puggy method.

In the grain formation process of the silver halide emulsion of the present invention, JP-A-5-72658 and JP-A-9-19-1
Chemically modified gelatin in which amino groups of gelatin are substituted as described in JP-A-97595 and JP-A-9-251193 can be preferably used. When a chemically modified gelatin is used in the particle forming step, 10% by mass or more of the total dispersion used for forming the particles is preferably the chemically modified gelatin, more preferably 30% by mass or more, and more preferably 50% by mass or more. Is more preferable. Amino group substitution ratio is 30
% Or more, more preferably 50% or more, and 80% or more.
The above is more preferred.

Examples of hydrophilic colloids other than gelatin that can be used as the protective colloid include 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 many kinds of synthetic hydrophilic high-molecular substances such as homo- or copolymers such as vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole and polyvinylpyrazole.

As a means for forming the silver halide emulsion of the present invention, various methods well known in the art can be used. That is, a single jet method, a controlled double jet method, a controlled triple jet method, or the like can be used in any combination. However, in order to obtain monodisperse grains, silver halide grains are generated. It is important to control pAg in the liquid phase in accordance with the growth rate of silver halide grains.
As the pAg value, a region of 7.0 to 12 is used, and preferably, a region of 7.5 to 11.0 can be used.
In determining the addition rate, refer to JP-A-54-48521.
And JP-A-58-49938. When the silver halide emulsion of the present invention is produced, a known silver halide solvent such as ammonia, thioether, thiourea or the like may be present, or the silver halide solvent may not be used. In the silver halide emulsion of the present invention, the pH / temperature in the ripening step is 7.0 to 11.0 / 40 ° C.
To 80 ° C, preferably 8.5 to 10.0 / 50 ° C to 70
C is more preferred.

The silver halide emulsion of the present invention is washed with water after the completion of the growth of silver halide grains in order to remove unnecessary soluble salts and, if necessary, dispersed in an aqueous solution containing a newly prepared dispersion medium. Preferably, there is. When removing the salts, use Research Disclosure (R
(Earth Disclosure, 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, A precipitation method (flocculation) using an anionic polymer (eg, polystyrene sulfonic acid) or a gelatin derivative (eg, acylated gelatin, carbamoylated gelatin, etc.) may be used. A method using a chemically modified gelatin obtained by substituting an amino group of gelatin described in JP-A-5-72658 can be preferably used.
Particularly, chemically modified gelatin in which amino groups of gelatin are phenylcarbamoylated is preferable. When chemically modified gelatin is used for removing salts, the substitution ratio of amino groups is preferably 30% or more, more preferably 50% or more, and even more preferably 80% or more.

In the silver halide emulsion according to the present invention, at least one of chalcogen sensitization such as sulfur sensitization and selenium sensitization and noble metal sensitization such as gold sensitization and palladium sensitization is used to prepare a silver halide emulsion. It can be applied in any of the steps.
It is preferable to combine two or more sensitization methods.
Various types of emulsions can be prepared depending on the step of chemical sensitization. There is a mode in which a chemical sensitizing nucleus is embedded inside the grain, a mode in which the chemical sensitizing nucleus is embedded at a position shallow from the grain surface, or a mode in which a chemical sensitizing nucleus is formed on the surface. In the silver halide emulsion according to the present invention, the location of the chemical sensitization nucleus can be selected according to the purpose. Generally preferred is the case where at least one kind of chemical sensitizing nucleus is formed near the surface.

One of the chemical sensitization methods that can be preferably performed on the silver halide emulsion of the present invention is a sensitization using a chalcogen compound and a sensitization using a noble metal alone or in combination. H. James), The Photographic Process, 4th Edition, Macmillan,
1977 (TH James, The Theor)
y of the Photographic Pro
ces, 4th ed, Macmi11an, 197
7) It can be carried out using active gelatin as described on pages 67-76, and can also be performed by Research Disclosure 120, April 1974, 12008; Research Disclosure 34, June 1975, 13
452, U.S. Patent Nos. 2,642,361 and 3,2
No. 97,446, No. 3,773,031, No. 3,
Nos. 857,711, 3,901,714, 4,226,018, and 3,904,415.
And pAg 5-10, pH 5-8 and temperature 30-70 as described in GB 1,315,755.
At 80 ° C., it can be sulfur, selenium, tellurium, gold, platinum, palladium or a combination of these sensitizers.

In the noble metal sensitization, for example, noble metal salts of gold, platinum and palladium can be used, and among them, gold sensitization, palladium sensitization and a combination of both are preferable. In the case of gold sensitization, for example, known compounds such as chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, and gold selenide can be used. The palladium compound means a divalent palladium salt or a tetravalent salt. Preferred palladium compounds are R ₂ Pd
It is represented by X ₆ or R ₂ PdX ₄ . Here, R represents a hydrogen atom, an alkali metal atom or an ammonium group.
X represents a halogen atom, and represents a chlorine, bromine or iodine atom. Specifically, for example, K ₂ PdCl ₄ , (N
H ₄ ) ₂ PdCl ₆ , Na ₂ PdCl ₄ , (NH ₄ ) ₂ PdC
l ₄ , Li ₂ PdCl ₄ , Na ₂ PdCl ₆ or K ₂ PdB
r ₄ is preferred. The gold compound and the palladium compound are preferably used in combination with a thiocyanate or a selenocyanate. When the emulsion of the present invention is subjected to gold sensitization, the preferred amount of the gold sensitizer is 1 × 10 ^-4 per mol of silver halide.
To 1 × 10 ⁻⁷ mol, more preferably 1 × 10 ⁻⁷ mol.
^{-5 to} 5 × 10 ^-7 mol. Similarly, when the emulsion of the present invention is subjected to palladium sensitization, the preferred range of the palladium sensitizer is 1 × 10 ^{−3 to} 5 × 10 ⁻⁷ mol. The preferred range of the thiocyan compound or selenocyan compound is 5
X 10 ^-2 to 1 x 10 ^-6 mol.

Examples of the sulfur sensitizer include hypo, thiourea compounds, rhodanine compounds and US Pat.
No. 7,711, 4,226,018 and 4,054,457 can be used. Chemical sensitization can also be performed in the presence of a so-called chemical sensitization aid. Useful chemical sensitization aids include compounds known to suppress fog in the course of chemical sensitization and increase sensitivity, such as azaindene, azapyridazine and azapyrimidine. Examples of chemical sensitization aid modifiers are described in US Pat. No. 2,131,038.
No. 3,411,914, No. 3,554,75
No. 7, JP-A-58-126526 and the aforementioned "Emulsion Chemistry" by Duffin, pp. 138-143.

When the emulsion of the present invention is subjected to sulfur sensitization, the preferred amount of the sulfur sensitizer is 1 × per mole of silver halide.
10 ^-4 to 1 × 10 ^-7 mol, more preferably 1
X ^{10-5 to} 5 x ^10-7 mol.

Selenium sensitization is a chalcogen sensitization method that can be preferably performed on the silver halide emulsion of the present invention. In the selenium sensitization, a known unstable selenium compound is used, and specifically, for example, colloidal metal selenium, selenoureas (eg, N, N-dimethylselenourea, N, N-diethylselenourea, etc.), Selenium compounds such as selenoketones and selenamides can be used. In some cases, selenium sensitization is preferably used in combination with sulfur sensitization or noble metal sensitization or both.

The silver halide emulsion of the present invention can contain various compounds for the purpose of preventing fog during the production process, storage or photographic processing of the photographic material, or stabilizing photographic performance. . That is, thiazoles, for example, benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptopenzimidazoles, mercaptothiadiazoles, Aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (especially 1-phenyl-5-mercaptotetrazole);
Mercaptopyrimidines; mercaptotriazines; thioketo compounds such as oxadrinethione; azaindenes such as triazaindenes and tetraazaindenes (especially 4-hydroxy-substituted (1,3,3
a, 7) Many compounds known as antifoggants or stabilizers, such as titraazaindenes), pentaazaindenes, can be added. For example, those described in U.S. Pat. Nos. 3,954,474 and 3,982,947 and JP-B-52-28660 can be used. One of the preferred compounds is disclosed in JP-A-63-212.
No. 932. Antifoggants and stabilizers are used at various times before, during and after particle formation, during the water washing step, during dispersion after water washing, before chemical sensitization, during chemical sensitization, after chemical sensitization, and before coating. It can be added according to the purpose. In addition to exhibiting the original antifogging and stabilizing effects by adding during emulsion preparation, it controls the crystal wall of the grains, reduces the grain size, reduces the solubility of the grains, controls the chemical sensitization, It can be used for various purposes such as controlling the arrangement of dyes.

The silver halide emulsion of the present invention may contain a spectral sensitizing dye. Further, it is a preferable embodiment that a spectral sensitizing dye is adsorbed on silver halide grains related to the present invention.

The spectral sensitizing dyes include methine dyes, and include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes, and complex merocyanine dyes. Any of nuclei usually used as basic heterocyclic nuclei in cyanine dyes can be applied to these dyes. That is, for example, a pyrroline nucleus, an oxazoline nucleus, a thiozoline nucleus, a pyrrole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, an imidazole nucleus,
A tetrazole nucleus, a pyridine nucleus; a nucleus in which an alicyclic hydrocarbon ring is fused to these nuclei; and a nucleus in which an aromatic hydrocarbon ring is fused to these nuclei, that is, for example, an indolenine nucleus and a benzindolenine nucleus , An indole nucleus, a benzoxadol nucleus, a naphthoxazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzimidazole nucleus, and a quinoline nucleus. These nuclei may be substituted on carbon atoms.

In the merocyanine dye or the complex merocyanine dye, as a nucleus having a ketomethylene structure, for example, a pyrazolin-5-one nucleus, a thiohydantoin nucleus,
5- to 6-membered heterocyclic nuclei such as thioxazolidine-2,4-dione nucleus, thiazolidine-2,4-dione nucleus, rhodanine nucleus and thiobarbituric acid nucleus can be applied.

These sensitizing dyes may be used alone or in combination, and the combination of sensitizing dyes is often used particularly for supersensitization. Representative examples are U.S. Pat. Nos. 2,688,545 and 2,972.
No. 7,229, No. 3,397,060, No. 3,5
No. 22,052, No. 3,527,641, No. 3,
Nos. 617,293, 3,628,964, 3,666,480, 3,672,898, 3,679,428, 3,703,377,
Nos. 3,769,301 and 3,814,609
No. 3,837,862, No. 4,026,70
7, UK Patent Nos. 1,344,281 and 1,50
7,803, JP-B-43-4936, 53-12
No. 375, JP-A-52-110618, JP-A-52-10
No. 9925.

Along with the sensitizing dye, a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization may be contained in the emulsion.

In the silver halide emulsion of the present invention, usually, the preferred timing of adding the spectral sensitizing dye is after the formation of silver halide grains. Most commonly, it is performed after completion of chemical sensitization but before coating, but US Pat. No. 3,628,9.
As described in JP-A-58-113928, spectral sensitization can be carried out simultaneously with chemical sensitization by adding a chemical sensitizer at the same time as described in JP-A-58-13928.
This can be carried out prior to chemical sensitization as described in the above paragraph, or it can be added before the completion of silver halide grain precipitation to start spectral sensitization. Furthermore, these compounds may be added separately, as taught in U.S. Pat. No. 4,255,666, i.e., some of these compounds may be added prior to chemical sensitization and the remainder may be chemically modified. It can be added after sensitization, and may be at any time during the formation of silver halide grains, including the method disclosed in U.S. Pat. No. 4,183,756.

The amount of addition was 4 × / mol of silver halide.
It can be used in the range of 10 ^-6 to 8 × 10 ^-3 mol, but when the silver halide grain size is 0.2 to 1.2 μm, about 5 × 10 ^-5 to 2 × 10 ^-3 mol is used. More effective.

In the silver halide photographic light-sensitive material to which the present invention relates, other than the silver halide emulsion of the present invention, even a normal crystal having no twin plane can be used.
Silver salt photography (Corona), p. 163, for example, a single twin including one twin plane, a parallel multiple twin including two or more parallel twin planes, and a non-parallel twin plane including two twin planes.
One or more non-parallel multiple twins can be selected and used according to the purpose. An example of mixing particles having different shapes is disclosed in U.S. Pat. No. 4,865,964, but this method can be selected as necessary.

In the case of a normal crystal, a cube having a (100) plane, an octahedron having a (111) plane, and JP-B-55-42.
No. 737 and Japanese Unexamined Patent Publication (Kokai) No. 60-222842 may use dodecahedral particles having a (110) plane. In addition, Journal of Imaging
Science, vol. 30, p. 247, 1986, the (211) plane as a representative (h
(11) plane particles, (hhl) plane particles typified by the (331) plane, (hk0) plane particles typified by the (210) plane, and (hkl) plane particles typified by the (321) plane. It requires some contrivance, but it can be selected and used depending on the purpose. Particles in which two or many planes coexist, such as a tetrahedral particle in which the (100) plane and the (111) plane coexist in one particle, and a particle in which the (100) plane and the (110) plane coexist according to the purpose. You can use it by choosing.

The silver halide grains related to the present invention include:
European Patent Nos. 96,727B1 and 64,412B1
No. 2,306,447C2, and surface modification as disclosed in Japanese Patent Application Laid-Open No. 60-221320. It is.

The surface of silver halide grains is generally flat, but irregularities can be intentionally formed. JP-A-58-106532 and JP-A-60-221320 disclose a method of forming a hole in a part of a crystal, for example, a vertex or a center of a plane, or U.S. Pat.
Raffle particles described in US Pat. No. 3,966 are examples.

In addition to the silver halide emulsion of the present invention, the silver halide photographic light-sensitive material of the present invention may be a so-called polydisperse emulsion having a wide grain size distribution or a so-called monodisperse emulsion having a narrow size distribution. Can be selected for use. In some cases, a variation coefficient of a diameter equivalent to a projected area of a particle or a diameter equivalent to a sphere of a volume is used as a scale representing a size distribution. When a monodisperse emulsion is used, it is preferable to use an emulsion having a size distribution with a coefficient of variation of 20% or less, more preferably 15% or less. In order to satisfy the target gradation of the light-sensitive material, two or more kinds of monodispersed silver halide emulsions having different grain sizes in the emulsion layer having substantially the same color sensitivity are mixed in the same layer or separated. Layers can be overlaid. Further, two or more kinds of polydisperse silver halide emulsions or a combination of a monodisperse emulsion and a polydisperse emulsion can be used as a mixture or as a mixture.

When the silver halide emulsion of the present invention is used as a light-sensitive material, the above-mentioned various additives are used. In addition, various additives can be used according to the purpose. These additives are described in more detail in Research Disclosure Item 17643 (December, 1978) and Item 18716 (November 1979).
Monday) and Item 308119 (December 1989)
Month).

The silver halide emulsion of the present invention can be used for various photographic light-sensitive materials. As one important aspect, the silver halide emulsion of the present invention is suitable for use in a multilayer photographic material having at least two silver halide emulsion layers. For example, in the case of a multilayer photographic light-sensitive material such as a color negative film or a color reversal film, the silver halide emulsion related to the present invention may be used on either the high-speed layer side or the low-speed layer side, and may be used for both. Is also good.

In constructing a color photographic material using the silver halide photographic emulsion of the present invention, the silver halide emulsion is
Use those that have been subjected to physical ripening, chemical ripening and spectral sensitization.

The additive used in such a step is R
D17643, page 23, section III to page 24, section VI-M, RD1
8716, pages 648 to 649 and RD308119, 9
It is described in page 96, section III-A to page 1000, section VI-M.

Known photographic additives which can be used in the present invention are also described in RD17643, page 25, VIII-A to page 27.
Section XIII, RD18716, pages 650 to 651, RD30
8119, page 1003, paragraphs VIII-A to 1012, XXI-E
Those described in the section can be used.

Various couplers can be used in the color light-sensitive material. Specific examples thereof are RD17643, 25
Page VII-C to G, RD308119, page 1001 VII-
It is described in sections C to G.

The additive used in the present invention is RD3081
19, page 1007, section XIV.

In the present invention, the aforementioned RD17643,
Page 28, section XVII, RD 18716, pages 647-8, and RD
The support described in section 308119, page 1009, XVII can be used.

The light-sensitive material includes RD308119, 1
An auxiliary layer such as a filter layer or an intermediate layer described in section VII-K on page 002 can be provided.

The photosensitive material is RD308119, VII
Various layer configurations such as a normal layer, a reverse layer, and a unit configuration described in the section -K can be adopted.

The silver halide photographic emulsion of the present invention can be used for various color light-sensitive materials represented by color negative films for general use or movies, color reversal films for slides or televisions, color papers, color positive films and color reversal papers. Can be preferably applied.

The light-sensitive material according to the present invention uses the above-mentioned RD17
643, pages 28 to 29, section XIX, RD18716, 651
And RD 308119, pages 1010 to 1011, section XIX.

[0139]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to these Examples.

Example 1 [Preparation of silver halide emulsion] (Preparation method of base emulsion Em-T1) A base emulsion Em-T1 was prepared according to the following procedure. [Nucleation step] The following gelatin solution B-11 in a reaction vessel
The pH was adjusted to 1.96 using 1N sulfuric acid while stirring at a stirring speed of 400 rpm using a mixing stirrer described in JP-A-62-160128. Then, S-11 liquid and X were applied using the double jet method.
Solution -11 was added at a constant flow rate for one minute to form nuclei. (B-11) Low molecular weight gelatin 3 having an average molecular weight of 20,000
13.0 L of aqueous solution containing 2.4 g and 9.92 g of potassium bromide (S-11) 237.5 m of 1.25 M silver nitrate aqueous solution
l (X-11) 1.25 M aqueous potassium bromide solution 23
7.5 ml After the addition was completed, the G-11 solution was added, and the temperature was raised to 60 ° C. over 30 minutes to adjust the pAg to 9.2. In this state, the mixture was maintained for 5 minutes, then, the pH was adjusted to 9.3 by adding an aqueous ammonia solution, and further maintained for 7 minutes. Then, the pH was adjusted to 6.1 using 1N nitric acid. (G-11) 3.37 L of an aqueous solution containing 139.1 g of alkali-treated inert gelatin having an average molecular weight of 100,000 and 4.64 ml of a 10% by mass methanol solution of the following [Compound A] [Compound A] HO (CH ₂ CH) ₂ O) _m [CH (CH ₃ ) CH ₂ O] ₂ O
(CH ₂ CH ₂ O) _n H (m + n = 10) [Grain growth step-1] After the nucleation step is completed, the S-12 solution and the X-12 solution are prepared by a double jet method while maintaining pAg at 9.2. Was added for 38 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the addition was about 12 times). After completion of the addition, the solution G-12 was added to adjust the stirring rotation speed to 550 rpm, and then the S-13 solution and the X-13 solution were accelerated while increasing the flow rates (the ratio of the flow rates at the end and the start). Is about 2
X) for 40 minutes. (S-12) 1.25 M aqueous silver nitrate solution 3.01 L (X-12) 1.25 M potassium bromide 3.01 L (G-12) 203.4 g of alkali-treated inert gelatin having an average molecular weight of 100,000, 2.02 L of an aqueous solution containing 6.2 ml of a 10% by mass methanol solution of [Compound A] (S-13) 1.66 L of a 3.5 M aqueous silver nitrate solution (X-13) 3.43 M of potassium bromide and 0.07 M
1.66 L of an aqueous solution containing potassium iodide (potassium iodide content: 2.0 mol%) is referred to as Em-T1.
Em-T1 has an average particle size of 1.375 μm and an average thickness of 0.3 μm.
This was a tabular emulsion having a particle size of 162 μm, a coefficient of variation in particle size of 16.6% and an average aspect ratio of 8.3. (Method for Preparing Comparative Emulsion Em-11) The above base emulsion Em-
Subsequently, particle growth was performed on T1 by the following method to prepare Em-11. [Particle Growth Step-2] After completion of Em-T1 particle growth step-1, pAg was adjusted to 7.9 while maintaining at 60 ° C.
While maintaining Ag, the S-104 solution and the X-104 solution were added while accelerating the flow rate. However, the addition at this time was carried out in advance by searching for the fastest addition conditions within a range in which no new nucleation would occur, separately from the base emulsion, and according to that. (S-104) 1.21 L of 3.5 M silver nitrate aqueous solution (X-104) 3.22 M of potassium bromide and 0.28 L
1.21 L of an aqueous solution containing potassium iodide of M (potassium iodide content: 8.0 mol%) After the completion of the growth, desalting and washing are carried out according to a conventional method, gelatin is added, and the mixture is dispersed well. PH 5.8,
The pAg was adjusted to 8.1. Thus, the emulsion Em-11
was gotten. (Preparation of Emulsion Em-12 of the Present Invention) The base emulsion Em-T1 was subjected to grain growth by the following method using a silver halide emulsion production facility having the same structure as in FIG. Was prepared. [Particle Growth Step-2] After completion of the Em-T1 particle growth step-1, while maintaining the temperature at 60 ° C., the volume of the reaction solution was concentrated to 7.05 L using an ultrafiltration apparatus (the volume before the concentration was reduced). (1/4, average distance between particles 1.81 μm). Subsequently, while maintaining the temperature at 60 ° C. and the pAg at 9.2, S-104
The solution and the X-104 solution were added for 35 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the addition at the start was 1.2 times). After completion of the growth, desalting and washing are performed according to a conventional method, and gelatin is added and dispersed well.
Ag was adjusted to 8.1. Thus, Emulsion Em-12 was obtained.

Table 1 shows the characteristics of Em-11 and Em-12.

[0142]

[Table 1]

In the low pAg growth emulsion (Em-11), a drastic reduction in growth rate and an increase in the coefficient of variation in particle size (deterioration of particle size distribution) are observed. Further, it can be seen that the average grain size has increased with respect to the base emulsion, and that the grains have grown somewhat in the lateral direction of the tabular grains. On the other hand, the emulsion (Em-12) prepared by using the intergranular distance control method has a grain size distribution equal to or greater than that of the base emulsion. In addition, since the average grain size is almost the same as that of the base emulsion, growth in the main plane direction alone has been achieved, and a layer having an average silver iodide content equal to the recipe design value is formed parallel to the main plane. You can see that

The average silver iodide content of the tabular silver halide grains in each silver halide emulsion in the region from the main plane to the depth of 5 nm was determined by EDX analysis using the above-mentioned analytical microscope. A specific measuring method will be described below.

After the gelatin in the silver halide emulsion was decomposed and removed, an embedded sample of silver halide particles was prepared, pretreated into an ultrathin section having a thickness of about 60 nm with an ultramicrotome, and subjected to EDX analysis with an analytical electron microscope. Was done. The analytical electron microscope used was HF-2000 manufactured by Hitachi, Ltd., and was used at an acceleration voltage of 200 kV. The analysis was performed after confirming the analysis site with a transmission electron microscope image, and then the electron beam probe diameter was 2 nm.
Measurement was performed for 50 seconds with a probe current of 1 nA, and
VOYAGER EDX manufactured by Instruments
The silver iodide content was calculated from the peak intensities of BrKα and ILα by the system. 100 for each emulsion
The average silver iodide content of each tabular silver halide grain was measured, and the average was determined for each emulsion. (Preparation of Emulsions Em-13 to 16) Em-13 to 16 were prepared in the same manner as in Em-12. However, the solutions shown in Table 2 were used instead of the X-104 solution. The addition rate was determined in advance for each emulsion in advance of the fastest addition condition within a range in which new nucleation did not occur separately from the base emulsion, and was performed in accordance therewith.

[0146]

[Table 2]

[Preparation of Color Photosensitive Material Sample and Performance Evaluation]
The silver halide emulsions Em-11 to Em are prepared as follows.
The photographic performance of -16 was evaluated.

Each of the emulsions Em-11 to Em-16 was treated with 52
C. while maintaining the sensitizing dyes SD-6, SD-7, SD
-8 was added. After aging for 20 minutes, chloroauric acid, potassium thiocyanate, sodium thiosulfate and triphenylphosphine selenide were added. The amount of sensitizing dye or sensitizer added and the ripening time were adjusted so that optimum sensitivity-fogging was obtained for each emulsion, and 1-phenyl-5-mercaptotetrazole and 4-hydroxy-6-methyl-1 , 3,
Stabilized by adding 3a, 7-tetraazaindene.

A coupler M-2 was dissolved in ethyl acetate and tricresyl phosphate and emulsified and dispersed in an aqueous solution containing gelatin, a spreading agent, a hardener, and the like. A general photographic additive was added to prepare a coating solution, which was coated on an undercoated cellulose triacetate film support by a conventional method and dried to obtain green-sensitive photosensitive material samples F-11 to F-16. Produced.

[0150]

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For each sample immediately after the preparation, 1/20 through a Toshiba glass filter (Y-48) using white light.
After performing a step wedge exposure by 3.2 CMS for 0 second, the following development processing was performed. Further, in order to evaluate the storage stability, each sample was subjected to the same treatment after a forced deterioration test (preserved at 40 ° C. and a relative humidity of 80% for 7 days). << Reference color development processing >> Processing step Processing time Processing temperature Replenishment amount * Color development 3 minutes 15 seconds 38 ± 0.3 ° C. 780 ml Bleaching 45 seconds 38 ± 2.0 ° C. 150 ml Fixing 1 minute 30 seconds 38 ± 2.0 ° C. 830 ml Stabilizing 60 seconds 38 ± 5.0 ° C. 830 ml drying 1 min 55 ± 5.0 ℃ - * the replenishing amount is a value per photosensitive material 1 m ^2.

The following color developing solutions, bleaching solutions, fixing solutions, stabilizing solutions and replenishers were used. Color developer Water 800 ml 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 Water was added to make 1 L, and the pH was adjusted to 10 using potassium hydroxide or 20% sulfuric acid. Adjust to 06. Color developing replenisher Water 800 ml 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 ml 1,3-Diaminopropanetetraacetic acid ammonium (III) ammonium 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 to make pH 4.4. Adjust to Bleach replenisher water 700 ml 1,3-diaminopropanetetraacetate ammonium iron (III) 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 ammonia water or glacial acetic acid, add water. To 1L. Fixing solution Water 800 ml 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 ml 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 ml Paraoctylphenyl polyoxyethylene ether (n = 10) 2.0 g Dimethylolurea 0.5 g Hexamethylenetetramine 0.2 g 1,2-Benzoisothiazolin-3-one 0.1 g Siloxane (UCC 0.1 g ammonia water 0.5 ml After adding water to make 1 L, the pH is adjusted to 8.5 using ammonia water or 50% sulfuric acid.

The sensitivity and fog of the obtained sample were measured using green light. The measuring method and conditions are shown below. Relative sensitivity was measured at the minimum concentration (Dmi
n) The reciprocal of the exposure amount giving a density of +0.2 was determined, and was shown as a relative value with the sensitivity of Sample F-11 being 100. The higher the relative sensitivity value, the higher the sensitivity, which is preferable. Relative fog was measured by measuring the density (= Dmin) of an unexposed portion of each sample, and expressed as a relative value with the Dmin value of Sample F-21 set to 100. The smaller the value of the relative fog, the lower the fog.

Similarly, the relative sensitivity fluctuation width and the relative fog fluctuation width were determined to evaluate the storage stability. The relative sensitivity variation width is obtained by calculating the absolute value (Δ sensitivity) of the difference between the reciprocal of the exposure amount that gives the density of the unexposed portion (Dmin) +0.2 immediately after the preparation of the sample and after the forced deterioration test. , Sample F-
The relative values are shown with the Δ sensitivity at 11 as 100. The smaller the value of the relative sensitivity variation width, the better the storage stability. Similarly, the relative fog fluctuation width is obtained by calculating the absolute value (Δfog) of the difference between the values of Dmin immediately after sample preparation and after the forced deterioration test in each sample (Δfog), and indicating the relative value of ΔFog in sample F-11 as 100. Was. The smaller the value of the relative fog fluctuation width, the better the storage stability.

Table 3 shows the results obtained for each sample.

[0156]

[Table 3]

A silver halide region is formed on the main plane of the grain of the base emulsion grain prepared by the intergrain distance control method,
And an average silver iodide content of 3 mol% or more in a region from the main plane of the tabular grains to a depth of 5 nm in the region.
It can be seen that the emulsion of the present invention in which the content is 5 mol% or less has excellent sensitivity and fog ratio, and also has good storage stability.

Example 2 [Preparation of silver halide emulsion] (Preparation method of base emulsion Em-T2) A base emulsion Em-T2 was prepared in the same manner as in Em-T1. [Particle Growth Step-1] S- used in the particle growth step-1
The following S-23 solution and X- solution instead of solution 13 and X-13 solution
23 liquids were used. (S-23) 1.66 L of 3.5 M aqueous silver nitrate solution (X-23) 3.325 M of potassium bromide and 0.17
1.66 L of an aqueous solution containing 5 M potassium iodide (potassium iodide content: 5.0 mol%) The base emulsion thus prepared is referred to as Em-T2.
Em-T2 has an average particle size of 1.324 μm and an average thickness of 0.3 μm.
This was a tabular emulsion having a particle size of 174 μm, a coefficient of variation of particle diameter of 19.2% and an average aspect ratio of 7.4. (Method for Preparing Comparative Emulsion Em-21) Base Emulsion Em-
On T2, particles were grown in the following manner to prepare Em-21. [Particle Growth Step-2] After the completion of Em-T2 particle growth step-1, pA was added at 60 ° C. with a 3.5 M aqueous potassium bromide solution.
g was adjusted to 10.5. Subsequently, at a temperature of 60 ° C. and pAg
While maintaining the temperature at 10.5, the S-204 solution and the X-204 solution were added while increasing the flow rate. However, the addition at this time was carried out in advance by searching for the fastest addition conditions within a range in which no new nucleation would occur, separately from the base emulsion, and according to that. (S-204) 0.75 L of 3.5 M silver nitrate aqueous solution (X-204) 3.458 M of potassium bromide and 0.0
0.75 L of an aqueous solution containing 42 M potassium iodide (potassium iodide content: 1.2 mol%) After the completion of the growth, desalting and washing are performed according to a conventional method, gelatin is added, and the mixture is dispersed well. PH 5.8,
The pAg was adjusted to 8.1. Thus, emulsion Em-21
was gotten. (Method for Preparing Comparative Emulsion Em-22) The above base emulsion Em-
On T2, particles were grown in the following manner to prepare Em-22. [Particle Growth Step-2] After the completion of Em-T2 particle growth step-1, 160 mmol of 4,5,6-triaminopyrimidine was added, and the mixture was aged at 60 ° C for 10 minutes. Subsequently, while maintaining the temperature at 60 ° C. and the pAg at 9.2, the S-204 solution and the X-204 solution were added while accelerating the flow rates. However,
The addition at this time was carried out in advance by searching for the fastest addition conditions within a range in which no new nuclei were formed separately from the base emulsion, and was performed in accordance therewith. After completion of the growth, desalting and washing are performed according to a conventional method, and gelatin is added and dispersed well.
At ℃, pH was adjusted to 5.8 and pAg to 8.1. Thus, an emulsion Em-22 was obtained. (Preparation of Emulsion Em-23 of the Present Invention) Using a silver halide emulsion production facility having the same structure as that shown in FIG. 1, the base emulsion Em-T2 was subjected to grain growth by the following method, followed by Em-23. Was prepared. [Grain Growth Step-2] After the completion of the Em-T2 particle growth step-1, 18 L of an aqueous solution containing 2% of alkali-treated inert gelatin having an average molecular weight of 100,000 and kept at 60 ° C was added,
An additional 60 ° C. water was added to bring the total volume of the reaction solution to 100
L (3.55 times the volume before dilution, average distance between particles: 4.37 μm). Subsequently, at a temperature of 60 ° C. and pAg9.
The solution S-204 and the solution X-204 were added while keeping the flow rate at 2, while increasing the flow rate. However, the addition at this time was carried out in advance by searching for the fastest addition conditions within a range in which no new nucleation would occur, separately from the base emulsion, and according to that. During the addition, the volume of the reaction solution was kept at 100 L by continuously performing a concentration operation using an ultrafiltration device connected to the reaction vessel. After completion of the growth, desalting and washing are performed according to a conventional method, and gelatin is added and dispersed well.
At 40 ° C., the pH and the pAg were adjusted to 5.8 and 8.1, respectively.
Thus, an emulsion Em-23 was obtained.

Table 4 shows the features of Em-21 to Em-23. The average silver iodide content in the region from the side surface to a depth of 5 nm was measured by EDX analysis using the above-mentioned analytical electron microscope. In the case of Em-T2, which is a base particle, a portion of the tabular particle as close to the edge as possible was measured. For each emulsion, three or more and 50 or more grains were measured per grain, and the arithmetic average of the results was determined as the average silver iodide content.

[0160]

[Table 4]

In the high pAg growth emulsion (Em-21), remarkable deterioration of the particle size distribution is observed. Further, it can be seen that the average thickness is increased with respect to the base emulsion, and the tabular grains are also slightly grown in the main plane direction. On the other hand, the emulsion (Em-23) prepared by using the intergranular distance control method has a grain size distribution equal to or greater than that of the base emulsion, and the average thickness is much larger than that of the base emulsion. From this, it can be determined that the growth was achieved almost only in the lateral direction and that an annular layer having an average silver iodide content almost equal to the recipe design value was formed. Further, the emulsion (Em-22) using the growth modifier also excels in both the particle size distribution and the lateral growth. (Preparation of Emulsions Em-24 to 26) Em-24 to 26 were prepared in the same manner as Em-23. However, the solutions shown in Table 5 were used instead of the X-204 solution. The addition rate was determined in advance for each emulsion in advance of the fastest addition condition within a range in which new nucleation did not occur separately from the base emulsion, and was performed in accordance therewith.

[0162]

[Table 5]

[Preparation of Color Photosensitive Material Sample and Performance Evaluation]
As in Example 1, each of the emulsions Em-21 to Em-26 was used.
Was used to produce green-sensitive photosensitive material samples F-21 to F-26, and each sample immediately after the production was exposed and developed. The sensitivity, fog and RMS value of the obtained sample were measured using green light. The measuring method and conditions are shown below.

Incidentally, the relative sensitivity was determined by comparing the sensitivity of Sample F-21 to 10
The relative fog is Dmi of the sample F-21.
The values are shown as relative values with the n value being 100. The measurement position of RMS is the density point of minimum density (Dmin) +0.2. R
The MS value was determined by scanning the measurement position of each sample with a microdensitometer (slit width 10 μm, slit length 180 μm) equipped with a Wratten filter (W-99) manufactured by Eastman Kodak Co., Ltd.
It was determined as the standard deviation of the density values of 0 or more. The relative RMS value was obtained by calculating the RMS value of each sample, and calculating the RMS value of the sample F-21.
The values are shown as relative values with the MS value being 100. It means that the smaller the value of the relative RMS, the better the granularity and the better.

Table 6 shows the results obtained for each sample.

[0166]

[Table 6]

A tabular silver halide grain grown in the lateral direction of a base grain prepared by the intergranular distance control method, having a depth of 5 nm from the side of the tabular silver halide grain.
It can be seen that the emulsion of the present invention in which the average silver iodide content in the region up to 5% is less than 5 mol% is excellent in sensitivity / fog ratio and sensitivity / granularity.

Example 3 [Preparation of Silver Halide Emulsion] (Preparation Method of Comparative Emulsion Em-31) The base emulsion Em-T1 prepared in Example 1 was subjected to grain growth by the following method. -31 was prepared. [Grain growth step-2] After completion of the particle growth step-1 of Em-T1, A having an average particle diameter of 0.05 μm was maintained at 60 ° C.
After adding 0.283 mole equivalent of gI fine grain emulsion, pAg
Was adjusted to 7.7, and the S-304 solution and the X-304 solution were added while accelerating the flow rates while maintaining the pAg. A small amount of the reaction solution was sampled to examine the grain shape at this stage (this emulsion was designated as Em-31C). (S-304) 0.90 L of 3.5 M aqueous silver nitrate solution (X-304) 3.22 M of potassium bromide and 0.28
0.90 L of an aqueous solution containing M potassium iodide [Grain growth step-3] Subsequently, the pAg was adjusted to 10.5 using a 3.5 M aqueous potassium bromide solution, and pAg was adjusted at 60 ° C.
While maintaining the g at 10.5, the S-305 solution and the X-305 solution were added while accelerating the flow rate. The addition of the solution was carried out in advance by searching for the fastest addition conditions within a range in which no new nuclei were formed, separately from the base emulsion, and was carried out accordingly. (S-305) 3.5 M aqueous silver nitrate solution 0.23 L (X-305) 3.5 M aqueous potassium bromide solution 0.2
3L After completion of the growth, desalting and washing are carried out according to a conventional method, gelatin is added and the mixture is well dispersed, and the pH is adjusted to 5.8 at 40 ° C.
The pAg was adjusted to 8.1. Thus, emulsion Em-31
was gotten. (Preparation Method of Comparative Emulsion Em-32) The base emulsion Em-T1 prepared in Example 1 was subsequently subjected to grain growth by the following method to prepare Em-32. [Grain growth step-2] The same process as in Em-31 was performed. [Grain growth step-3] pAg after completion of the particle growth step-2
The mixture was adjusted to 9.2, 178 mmol of 4,5,6-triaminopyrimidine was added, and the mixture was aged at 60 ° C. for 10 minutes. Subsequently, while maintaining the temperature at 60 ° C. and pAg 9.2, S-
Liquid 305 and liquid X-305 were added while accelerating the flow rate. The addition of the solution was carried out in advance by searching for the fastest addition conditions within a range in which no new nuclei were formed, separately from the base emulsion, and was carried out accordingly. After the above-mentioned growth is completed, desalting and washing are performed according to a conventional method.
The pH was adjusted to 5.8 and the pAg to 8.1 at 0 ° C. Thus, Emulsion Em-32 was obtained. (Preparation of Emulsion Em-33 of the Present Invention) Grain growth was carried out on the base emulsion Em-T1 prepared in Example 1 by the following method using a silver halide emulsion production facility having the same structure as that of FIG. This was performed to prepare Em-33. [Particle Growth Step-2] After the completion of the Em-T1 particle growth step-1, while maintaining the temperature at 60 ° C., the volume of the reaction solution was adjusted to 7.05 L by using an ultrafiltration apparatus (the distance between dense average particles: 1.8).
1 μm). Continue with an average particle size of 0.05 μm
Was added in an amount equivalent to 0.283 mol of the AgI fine grain emulsion of
While maintaining the temperature at 60 ° C. and pAg 9.2, the S-304 solution and the X-304 solution were added for 33 minutes while accelerating the flow rates (the ratio of the addition flow rate at the end to the start was 1.2 times). A small amount of the reaction solution was collected to determine the particle shape at this stage (this emulsion was designated as Em-33C). [Grain Growth Step-3] Subsequently, 18 L of an aqueous solution containing 2% of alkali-treated inert gelatin having an average molecular weight of 100,000 and maintained at 60 ° C. is added, and water at 60 ° C. is further added to reduce the total volume of the reaction solution. It was diluted to 100 L (average distance between particles: 4.37 μm). Subsequently, while maintaining the temperature at 60 ° C. and the pAg at 9.2, the S-305 solution and the X-305 solution were added in about 2 minutes while accelerating the flow rates. During the addition, the volume of the reaction solution was kept at 100 L by continuously performing a concentration operation using an ultrafiltration device connected to the reaction vessel. After completion of the growth, desalting and washing were carried out according to a conventional method, gelatin was added and the mixture was well dispersed, and the pH was adjusted to 5.8 and the pAg was adjusted to 8.1 at 40 ° C. Thus, emulsion E
m-33 was obtained.

Em-31 to Em-33 and Em-31
Table 7 summarizes the shape characteristics of C and Em-33C.

[0170]

[Table 7]

The grain size of Em-31C by the low pAg growth method is larger than that of the base emulsion Em-T1. Em-33C, on which the layer structure was grown, was used as the base emulsion E
It can be seen that the grains have a grain size substantially equal to m-T1 and are selectively grown only in the main plane direction. Furthermore, Em-
It can be seen that in Em-33 after the growth in the side direction from 33C (annular layer structure growth), the growth is only in the side direction without increasing the thickness substantially from Em-33C. As described above, the control of the growth characteristics by the interparticle distance control method can be effectively used in combination. (Preparation of Emulsion Em-34 of the Present Invention) Em-34 was prepared by the following procedure using a silver halide emulsion production facility having the same structure as in FIG. [Nucleation Step] The nucleation step was performed in the same manner as in the base emulsion Em-T1. [Particle Growth Step-1] After the nucleation step, G-32 solution was added, and water at 60 ° C. was further added to dilute the total volume of the reaction solution to 100 L (average distance between particles: 4.37 μm).
m). Subsequently, while maintaining the pAg at 9.2, the flow rates of the S-12 solution and the X-12 solution are accelerated by the double jet method (the ratio of the addition flow rate at the end to the addition at the start is about 12 times) 38
Minutes. After completion of the addition, the stirring rotation speed is adjusted to 550 rpm, and subsequently, the flow rates of the S-13 solution and the X-13 solution are accelerated (the ratio of the addition flow at the end to the start is about twice) for 40 minutes. Was added. (G-32) 2.02 L aqueous solution containing 203.4 g of alkali-treated inert gelatin having an average molecular weight of 100,000 [Grain growing step-2]
While maintaining the temperature at 0 ° C., the volume of the reaction solution was concentrated to 7.05 L (average distance between particles 1.81 μm) using an ultrafiltration apparatus. Subsequently, 0.283 mol equivalent of an AgI fine grain emulsion having an average particle size of 0.05 μm was added.
C and pAg 9.2 while maintaining the S-304 solution and X-30.
The four solutions were added for 33 minutes while accelerating the flow rate (the ratio of the addition flow rate at the end to the addition at the start was 1.2 times). [Grain Growth Step-3] Subsequently, 18 L of an aqueous solution containing 2% of alkali-treated inert gelatin having an average molecular weight of 100,000 and maintained at 60 ° C. is added, and water at 60 ° C. is further added to reduce the total volume of the reaction solution. It was diluted to 127 L (average interparticle distance 4.74 μm). Subsequently, while maintaining the temperature at 60 ° C. and the pAg at 9.2, the S-305 solution and the X-305 solution were added in about 2 minutes while accelerating the flow rates. During the addition, the volume of the reactant solution was maintained at 127 L by performing a continuous concentration operation using an ultrafiltration device connected to the reaction vessel. After completion of the growth, desalting and washing were carried out according to a conventional method, gelatin was added and the mixture was well dispersed, and the pH was adjusted to 5.8 and the pAg was adjusted to 8.1 at 40 ° C. Thus, emulsion E
m-34 was obtained. Em-34 has an average particle size of 1.86.
3 μm, average thickness 0.125 μm, variation coefficient of particle size 1
This was a tabular emulsion having 6.2% and an average aspect ratio of 14.5.

From observation by a transmission electron microscope, it was found that the emulsions Em-33 and Em-34 of the present invention contained tabular grains having 10 or more dislocation lines in the peripheral region and at least one dislocation line in the central region of the main plane. It was confirmed that it was present at a ratio of 90% or more to the tabular grains contained in the emulsion.
From the measurement of the surface iodine content distribution of the main plane of the tabular grains contained in each of the above emulsions using TOF-SIMS, the emulsions Em-33 and Em-34 of the present invention showed that It was confirmed that 50% or more of tabular grains having a surface silver iodide content in the region along the edge lower than the surface silver iodide content in the central region of the main plane by 3 mol% or more were included.
On the other hand, the tabular grains contained in the comparative emulsions Em-31 and Em-32 had a substantially constant surface iodine content distribution in the main plane. [Production of Color Photosensitive Material Samples and Performance Evaluation] As in Example 1, green-sensitive photosensitive material samples F-31 to F-34 were prepared using the emulsions Em-31 to Em-34, and immediately after the preparation. Each sample was exposed and developed. Further, in order to evaluate the pressure resistance, each sample was subjected to 23 ° C. and a relative humidity of 5 ° C.
After holding for 24 hours in an atmosphere of 5%, a 5 g load was applied to a needle having a tip having a radius of curvature of 0.025 mm at a constant speed using a scratch strength tester (manufactured by Shinto Kagaku) under the same conditions. The surface of the sample was scanned with and the same processing was performed.

The sensitivity, fog and RMS value of the obtained sample were measured using green light. The measuring method and conditions are the same as in Examples 1 and 2. Each relative value was shown as a value with the value of sample F-31 being 100.

The pressure resistance was evaluated as follows. The density increase due to the pressure is measured by measuring the density increase amount of the unexposed portion where the load is applied, and reducing the density increase amount of the sample F-31 by one.
The relative value (ΔDp1) was set to 00 (the smaller the value, the smaller the increase in fog density due to the pressure applied, and the better the pressure resistance). The decrease in sensitivity due to the pressure being applied is (D
The density decrease of the portion where the load was applied in the density part of (max-Dmin) / 2 was measured, and the relative decrease (ΔDp2) with the concentration decrease of the sample F-31 being 100 (the smaller the value, the smaller the value). This means that the decrease in sensitivity due to pressure is small and the pressure resistance is excellent).

Table 8 shows the results obtained for each sample.

[0176]

[Table 8]

In the results shown in Table 8, F-31 to F-3
By comparing No. 3 with the tabular grains formed using the intergranular distance control method, the grains were grown in the direction perpendicular to the main grain plane of the base emulsion grains, and further grown in the side direction of the base emulsion grains. 5 depths from the main plane of silver halide grains
the average silver iodide content in the region up to
Mol% or less, and the emulsion of the present invention having an average silver iodide content of less than 5 mol% in a region from the side surface to a depth of 5 nm,
It can be seen that the sensitivity / fog ratio, the sensitivity / granularity ratio were excellent, and the pressure resistance was also improved. F-33 and F-34
In comparison, in the silver halide emulsion having the features of the present invention, by increasing the aspect ratio of tabular grains,
It can be seen that better performance can be obtained.

[0178]

According to the present invention, it is possible to obtain a photographic silver halide emulsion which is excellent in sensitivity / fog ratio, sensitivity / granularity, storage stability and pressure resistance.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a silver halide emulsion manufacturing apparatus applicable to the manufacturing equipment of the present invention.

FIG. 2 is a diagram illustrating the structure of a tabular silver halide grain of the present invention.

FIG. 3 is a diagram illustrating a region along an edge in a main plane of a tabular silver halide grain.

[Description of Signs] 1 Reaction vessel 2 Stirring mechanism 3 Dispersion medium 4 Silver addition line 5 Halide addition line 6 Dispersion medium addition line 7 Addition line 8 Liquid take-out line 9 Liquid return line 10 Permeate discharge line 11 Permeate return line 12 Limit Outer filtration unit 13 Circulation pump 14 Flow meter 15, 16, 17 Pressure gauge 18 Pressure regulating valve 19 Flow regulating valve 20 Silver addition valve 21 Halide addition valve 22 Liquid extraction valve 23, 24, 25 Valve 26 Ultrafiltration permeate 27 Permeate receiving container 28 Scale

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadahiro Nagasawa 1 Konica Corporation, Sakura-cho, Hino-shi, Tokyo In-house F-term (reference) 2H023 BA00 BA01 BA03 BA04 BA05

Claims (11)

[Claims] Claims: 1. A silver halide emulsion containing tabular silver halide grains grown in a direction perpendicular to the main grain plane of a base emulsion grain using a grain-to-grain distance control method. The average silver iodide content of the tabular silver halide grains in the region from the grain major plane to a depth of 5 nm in the silver halide area formed on the grain major plane of the base emulsion grains is 3 mol% to 15 mol%. A silver halide emulsion containing the following tabular silver halide grains. 2. A silver halide emulsion containing tabular silver halide grains grown in the lateral direction of a base emulsion grain using a grain-to-grain distance control method, wherein the side faces of the tabular silver halide are controlled. A silver halide emulsion comprising silver halide grains having an average silver iodide content of less than 5 mol% in the region from to a depth of 5 nm. 3. Tabular silver halide grains obtained by growing grains in a direction perpendicular to the main plane of the grains of the base emulsion grains and further growing grains in the side direction of the grains of the base emulsion grains by using an inter-grain distance control method. Wherein the average iodine concentration in a region extending from the main plane of the tabular silver halide grains to a depth of 5 nm in the silver halide area formed on the main plane of the grains of the base emulsion grains. Silver halide content of 5 mol%
Not less than 15 mol% and tabular silver halide grains having an average silver iodide content of less than 5 mol% in a region from the side surface to a depth of 5 nm of the tabular silver halide. Silver halide emulsion. 4. An average silver iodide content of the tabular silver halide grains in a region from the main plane of the grains to a depth of 5 nm is 5 mol% or more and 12 mol% or less. 3. The silver halide emulsion according to item 3. 5. The halogen according to claim 2, wherein the average silver iodide content in a region from the side surface of the tabular silver halide to a depth of 5 nm is less than 3 mol%. Silver halide emulsion. 6. A halide comprising tabular silver halide grains having a surface silver iodide content in a region along an edge of a main plane lower than a surface silver iodide content in a central region of the main plane. Silver emulsion. 7. The silver halide emulsion according to claim 6, wherein said silver halide grains are formed by a grain distance control method. 8. The silver halide emulsion according to claim 1, wherein the tabular silver halide grains have an average of 10 or more dislocation lines per grain. 9. The silver halide emulsion according to claim 1, wherein the average aspect ratio of the tabular silver halide grains is from 3 to 100. 10. The method according to claim 1, wherein the coefficient of variation of the particle size of said tabular silver halide grains is 25% or less.
10. The silver halide emulsion according to any one of items 1 to 9. 11. A silver halide photographic material comprising the silver halide emulsion according to claim 1. Description: