JP2002040587A - Method for preparing flat platy silver halide photographic emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a flat platy grained silver halide photographic emulsion having a high aspect ratio and a narrow grain size distribution. SOLUTION: In the method for preparing a flat platy silver halide photographic emulsion by forming flat platy grained nuclei by the formation of nuclear fine grains and subsequent aging and then growing the flat platy grained nuclei, a globular protein is allowed to exist in the formation of the nuclear fine grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a tabular grain silver halide photographic emulsion having a high aspect ratio and a narrow grain size distribution.

[0002]

2. Description of the Related Art Tabular silver halide grains (hereinafter referred to as "tabular grains") have the following photographic characteristics: 1) Ratio of surface area to volume (hereinafter referred to as specific surface area).
And a large amount of sensitizing dye can be adsorbed on the surface, so that the color sensitization sensitivity is relatively higher than the intrinsic sensitivity. 2) When an emulsion containing tabular grains is coated and dried, the grains are arranged parallel to the surface of the support, so that the thickness of the coating layer can be reduced and the photographic light-sensitive material has good sharpness. 3) In a radiographic system, when a sensitizing dye is added to tabular grains, silver halide crossover light can be significantly reduced, and deterioration of image quality can be prevented. 4) An image with low light scattering and high resolution can be obtained. 5) The green photosensitive layer or
When used in the red photosensitive layer, the yellow filter can be removed from the emulsion. Because of these many advantages, tabular grains have been used in commercially available high-sensitivity photographic materials. Tokuhei 6
JP-A-44132 and JP-B-5-16015 disclose tabular grain emulsions having an aspect ratio of 8 or more. The aspect ratio here is indicated by a ratio of a diameter to a thickness of a tabular grain. Further, the diameter of a grain refers to the diameter of a circle having an area equal to the projected area of the grain when the emulsion is observed with a microscope or an electron microscope. The thickness is indicated by the distance between two parallel main surfaces constituting the tabular silver halide. Japanese Patent Publication No. 4-36374 discloses that at least one of a green-sensitive emulsion layer and a red-sensitive emulsion layer has a thickness of 0.3.
There is described a color photographic light-sensitive material in which sharpness, sensitivity and graininess are improved by using tabular grains having a diameter of less than μ and a diameter of 0.6 μ or more.

However, in recent years, the sensitivity and size of silver halide light-sensitive materials have been increased, and color light-sensitive materials having higher sensitivity and improved image quality have been strongly desired. For this reason, silver halide grain emulsions having higher sensitivity and better graininess are required, and conventional tabular silver halide emulsions are insufficient to meet these demands, and are further required. The performance improvement was desired.

Further, the tabular grains having a larger aspect ratio have a larger specific surface area, so that the above advantages of the tabular grains can be greatly utilized. That is, by adsorbing more sensitizing dyes to a larger surface area, it becomes possible to obtain high sensitivity by increasing the amount of light absorption per particle. Therefore, many methods for preparing thinner tabular grains have been studied. Japanese Patent Publication No. 5-12696 discloses a method for preparing thin tabular grains using gelatin in which methionine groups in gelatin have been oxidized and invalidated as a dispersion medium. Japanese Patent Application Laid-Open No. 8-82883 discloses a method for preparing thin tabular grains using gelatin in which amino groups and methionine groups have been invalidated as a dispersion medium. JP-A-10-148897 discloses a method for preparing thin tabular grains by chemically modifying an amino group in gelatin and using gelatin having at least two or more carboxyl groups introduced therein as a dispersion medium.

On the other hand, in order to achieve both high sensitivity and good graininess, it is necessary that the distribution of the equivalent circle diameter of the tabular grains and the distribution of the thickness of the tabular grains are monodisperse. Many techniques have been developed so far to obtain monodisperse tabular grains. Japanese Patent Publication No. 5-61205 discloses a monodisperse tabular grain emulsion in which tabular grains are hexagonal and the coefficient of variation of the equivalent circle diameter is 20% or less. U.S. Pat. No. 5210013 discloses a tabular grain emulsion in which the coefficient of variation in equivalent circle diameter of tabular grains prepared using an alkylene oxide block copolymer is 10% or less. These disclosed techniques are techniques for achieving monodispersion in a tabular grain growth step.

On the other hand, several attempts have been made to achieve monodispersion in the formation of plate nuclei. JP-A-5-197555 discloses a method of obtaining monodisperse tabular grains by forming nuclei into spherical monodisperse seed crystals after forming tabular nuclei and then growing them. US Patent No. 4014
No. 014 discloses that tabular grain nucleation is performed with relatively high pBr. EP 610796 discloses a technique for terminating tabular grain nucleation in a short time. Japanese Patent Publication No. 7-11670 discloses that core fine particles are formed at a low temperature of 5 to 38 ° C. European Patent No. 533152 discloses a technique in which nucleus fine particles are formed on silver bromide flat plates under conditions of excess chloride and grown under conditions of no excess chloride. No. 51
No. 04786 describes NaBr containing gelatin in a thin tube.
There is disclosed a technique in which fine particles are formed in a tube by passing a solution at a high speed and silver nitrate is injected into the tube, followed by physical ripening to prepare tabular grain nuclei. In the formation of the core fine particles described in the patent, the core fine particles formed first and the core fine particles formed later are not mixed, and the histories of all the core fine particles can be made the same. The technology described in the patent makes it impossible to do so far by adding a silver nitrate solution and a halide solution to a reaction vessel holding a protective colloid under stirring for a certain period of time. there were. In Japanese Patent Publication No. Hei 7-23218,
A mixer is provided outside the reaction vessel in which the grain growth is performed, and a silver nitrate aqueous solution and a halide aqueous solution containing gelatin are continuously supplied to the mixer to form core fine particles, and immediately, the core fine particle emulsion is continuously reacted. A technique for obtaining a plate nucleus by physical ripening after transferring to a container is disclosed. Also in this case, since the core fine particles generated by the mixer are continuously transferred from the mixer to the reaction vessel, it is possible to equalize the flat plate nuclei by making the history of each core fine particle the same.

[0007] Japanese Patent No. 2631158 discloses that a silver nitrate solution and a halide solution are respectively guided to multiple nozzles through different paths by using multiple coaxial nozzles in the formation of nuclear fine particles, and the two react at the outlet to form nuclear fine particles. A method for doing so is disclosed. Similarly, U.S. Pat. No. 5,484,697 discloses a method for forming fine core particles using a double tube or a T-tube. The method of forming fine core particles in the formation of these tabular grains is more advanced than the conventional method in which a silver nitrate solution and a halide solution are added to a reaction vessel having a protective colloid solution under vigorous stirring, and the uniform flat plate is advanced. It makes the preparation of the nucleus possible.

Although the techniques described so far have increased the possibility of obtaining tabular grain emulsions having a high aspect ratio and a narrow grain size distribution, there are effective means for freely controlling the grain size of tabular grains. Was needed. The number of nuclei in tabular grains is governed by the probability of twinning in the formation of nucleated particles, which is determined by the probability of aggregation between the particles generated during the formation of nucleated particles, J. Imag.
i. 39, 323 (1995) and 42
487 (1998). That is, in order to obtain desired tabular grains, a technique capable of freely controlling the twin formation probability in forming core fine particles has been desired.

[0009]

An object of the present invention is to provide a method for producing a silver halide emulsion comprising tabular grains having a high aspect ratio and a narrow grain size distribution.

[0010]

The object of the present invention has been attained by the following method. (1) By forming tabular grain nuclei by nucleus fine grain formation and subsequent ripening, and growing the tabular grain nuclei,
A process for producing a tabular silver halide photographic emulsion, characterized in that a spherical protein is present at the time of forming fine core particles in the process of producing the tabular silver halide emulsion.

(2) A mixer is provided outside the reaction vessel in which silver halide grains are grown, and an aqueous solution of silver nitrate and an aqueous solution of a water-soluble halide are continuously supplied to the mixer. By forming the core fine particles, supplying the core fine particles to the reaction vessel, and aging the core fine particles in the reaction vessel, a tabular grain nucleus is formed, and the tabular grain nucleus is grown. A method for producing a tabular silver halide photographic emulsion, wherein a spherical protein is present during the formation of the fine core particles. (3) The method for producing a tabular silver halide photographic emulsion according to (2), wherein the silver halide fine particles formed in the mixer are immediately supplied to the reaction vessel. (4) The step of supplying the core fine particles formed in the mixer to the reaction vessel over 5 minutes or more, and subsequently performing aging in the reaction vessel to form tabular grain nuclei. A method for producing the tabular silver halide photographic emulsion described above. (5) The size of the globular protein is 500 A or less on the long axis and 1 on the short axis.
The method for producing a tabular silver halide photographic emulsion according to any one of (1) to (3), wherein the average molecular weight is 100,000 or less. (6) In a method for producing a silver halide tabular grain emulsion comprising the steps of nucleus fine grain formation, tabular grain nucleation by ripening and growth, at least a compound represented by the following general formula (I), (II) or (III): 6. The method for producing a silver halide emulsion according to claim 1, wherein at least one kind is not present at the time of nucleation but is present at the time of ripening and / or growing.

Embedded image(Where R₁ Is an alkyl group, alkenyl group, aralkyl
R represents a group_Two , R_Three, R_Four , R_Five And R₆ Haso
Each represents a hydrogen atom or a substituent. R_Two And R _Three , R
_Three And R_Four , R_Four And R_Five , R_Five And R₆ Is fused
Good. Where R_Two , R_Three , R_Four , R_Five And R₆ 
At least one represents an aryl group. X^-Is Anio
Represents

Embedded image (Wherein A ₁ , A ₂ , A ₃ and A ₄ each represent a group of non-metallic atoms for completing a nitrogen-containing heterocyclic ring, each of which may be the same or different. B represents a divalent linking group And m represents 0 or 1. R ₁ and R ₂ each represent an alkyl group, X represents an anion, and n represents 0 or 1.
Or 2 and n is 0 or 1 in the case of an inner salt.

The tabular silver halide grains in the present invention have two opposing parallel main surfaces and have a circle equivalent diameter of the main surface (the diameter of a circle having the same projected area as the main surface). Particles that are at least four times larger than the distance between them (that is, the thickness of the particles). The average grain diameter / grain thickness ratio of the tabular grains prepared by the method of the present invention is preferably from 8 to 500, and more preferably from 10 to 500. Here, the average grain diameter / grain thickness can be obtained by averaging the grain diameter / thickness ratio of all tabular grains. As a simple method, the average diameter of all tabular grains and the average thickness of all tabular grains are used. It can also be obtained as the ratio of In the tabular grain emulsion of the present invention, the ratio of the projected area of tabular grains to the projected area of all silver halide grains is 50% or more;
It is preferably at least 70%, more preferably at least 90%, even more preferably at least 95%.

The diameter (corresponding to a circle) of the tabular grains of the present invention is 0.1.
It is 6 to 20 μm, preferably 0.8 to 20 μm. The particle thickness is less than 0.3 μm, preferably 0.2 to 0.01
μm, and more preferably 0.1 to 0.01 μm.
The measurement of the particle diameter and the particle thickness in the present invention can be obtained from an electron micrograph of the particles as in the method described in US Pat. No. 4,434,226. That is, the measurement of the thickness of the particles is as follows.
A metal can be vapor-deposited from the diagonal direction of the particles together with a reference latex, the length of the shadow is measured on an electron micrograph, and calculated by referring to the length of the latex shadow.

The main surface of the tabular grain of the present invention is (11).
They are broadly divided into 1) and (100). A tabular grain having a (111) plane as a main surface is a general term for silver halide grains having one twin plane or two or more parallel twin planes. The twin plane refers to the (111) plane when ions at all lattice points on both sides of the (111) plane are in a mirror image relationship.
These tabular grains have a triangular shape, a hexagonal shape or a rounded shape when viewed from above, and the triangular shape is triangular, and the hexagonal shape is hexagonal, rounded. Tabular grains have mutually parallel outer surfaces with rounded corners.

The method for producing a silver halide emulsion comprising tabular grains according to the present invention comprises the following steps. [1] Formation of core fine particles A silver ion solution and a halide ion solution are mixed in the presence of a protective colloid to form core fine particles. The nucleus fine particles include both normal crystals having no twin planes and twin grains having one or more twin planes. The ratio of normal crystals / twin crystals depends on the preparation conditions, method, apparatus and the like of the core fine particles.
The particle size of the core fine particles is 0.001 μm or more and 0.1 μm or more.
05 μm or less, preferably 0.01 μm or more and 0.03 μm
m or less. [2] Tabular grain nucleus formation by ripening By ripening the nucleus fine grains, the normal crystal nucleus fine grains having no twin plane dissolve and disappear, and the tabular nucleus fine grains having twin planes grow to ripen. Upon completion of the above, tabular grain nuclei of almost only tabular grains are formed. The physical ripening is performed at a temperature of 40 ° C. to 100 ° C., preferably 50 ° C. to 90 ° C. [3] Growth The tabular grain nuclei are grown by supplying silver ions and halide ions to the tabular grain nucleus emulsion so that nuclei do not newly form. As described above, as one preferred method, silver halide emulsion fine grains are added to grow tabular grain nuclei.

US Pat. Nos. 4,434,226 and 4,439,520 describe methods for producing (111) major surface type tabular grains.
Nos. 4,441,310, 4,433,048, 44
No. 14,306, No. 4,459,353 disclose the production method and use technology thereof. Also, Japanese Patent Application Laid-Open No. Hei 6-214331
As disclosed in U.S. Pat. No. 5,085,097, once nucleation is performed to obtain a seed crystal, it is adjusted to pH, p, and pH for convenient growth.
By setting conditions such as Ag, silver and a halogen solution are added for growth, and tabular grains can be formed. As a preferable method, tabular grains are formed by adding silver halide fine particles instead of adding a silver salt aqueous solution and a halide aqueous solution to a reaction vessel holding a protective colloid aqueous solution. This method is described in US Pat.
The technology is disclosed in Japanese Patent Application Laid-Open Nos. 1-183644, 2-43535, 2-43535 and 2-68538. As a method for supplying iodine ions in forming tabular grains, a fine grain silver iodide (having a grain size of 0.1 μm or less, preferably 0.06 μm or less) emulsion may be added. It is preferable to use the manufacturing method disclosed in US Pat. No. 4,879,208.

The tabular grain emulsion of the present invention is preferably a monodisperse tabular grain. In this regard, JP-A-63-1
1928 and JP-B-5-61205 disclose monodisperse hexagonal tabular grains, and JP-A-1-131541 discloses circular monodisperse tabular grains. In JP-A-2-838, more than 95% of the total projected area is occupied by tabular grains having two twin planes parallel to the main surface, and the size distribution of the tabular grains is monodisperse. Certain emulsions have been disclosed.
EP 514 742 A discloses tabular grain emulsions prepared using a polyalkylene oxide block copolymer and having a coefficient of variation in grain size of 10% or less.

The following patent discloses silver chloride or a (111) flat plate having a high silver chloride content used in the present invention. U.S. Patent No. 4,414,306, U.S. Patent No. 4,400,463, U.S. Patent No. 4,713,323
No. 4,783,398; U.S. Pat.
No. 491, U.S. Pat. No. 4,983,508, U.S. Pat.
No. 804621, US Pat. No. 5,389,509, US Pat. No. 5,217,858, US Pat. No. 5,460,934.

The high silver bromide (111) tabular grains used in the present invention are described in the following patents. U.S. Pat. No. 4,425,425, U.S. Pat. No. 4,425,426,
U.S. Pat. No. 4,443,426; U.S. Pat. No. 4,439,520
No. 4,414,310; U.S. Pat.
048, U.S. Pat. No. 4,647,528, U.S. Pat.
No. 665012, U.S. Pat. No. 4,672,027, U.S. Pat. No. 4,678,745, U.S. Pat. No. 4,684,607,
U.S. Pat. No. 4,593,964, U.S. Pat.
6, U.S. Pat. No. 4,722,886, and U.S. Pat.
5617, U.S. Patent No. 4,755,456, U.S. Patent No. 4,806,461, U.S. Patent No. 4,801,522, U.S. Patent No. 4,835,322, U.S. Patent No. 4,839,268,
U.S. Pat. No. 4,914,014, U.S. Pat.
5, U.S. Pat. No. 4,977,074, U.S. Pat.
No. 5,350, U.S. Pat. No. 5,061,609, U.S. Pat. No. 5,061,616, U.S. Pat. No. 5,068,173, U.S. Pat. No. 5,132,203, U.S. Pat.
No. 5,334,469, U.S. Pat.
No. 495, US Pat. No. 5,358,840, US Pat.
372927.

With respect to the (100) flat plate used in the present invention, US Pat.
No. 156, U.S. Pat. No. 5,275,930, U.S. Pat.
No. 2,926,632, US Pat. No. 5,314,798, US Pat. No. 5,320,938, US Pat. No. 5,319,635,
U.S. Pat. No. 5,356,764, European Patent No. 5,699,971
No., EP 737887, JP-A-6-30864
No. 8, JP-A-9-5911.

The halogen composition of the tabular grains includes silver iodobromide, silver chloroiodobromide, silver iodochloride, silver iodobromochloride, silver chlorobromide and silver chloride. Regarding the structure relating to the halogen composition of the tabular grains of the present invention, X-ray diffraction, EPMA (XMA
Method (which scans silver halide grains with an electron beam to detect silver halide composition), ESCA
(Method of irradiating X-rays to split photoelectrons emitted from the particle surface) and the like can be confirmed. In the present invention, the grain surface refers to a region up to a depth of about 50 ° from the surface, and its halogen composition is usually E
It can be measured by the SCA method. The inside of the particle refers to a region other than the above-described surface region.

The globular proteins used in the present invention include, for example, casein, lysozyme, hemoglobin, myoglobin,
Pepsin, ovalmin, globulin, myosin, albumin, etc., whose three-dimensional structure has a major axis of 50
0 ° or less, 20 ° or more, and short axis is 100 ° or less, 15 °
The ratio of the major axis to the minor axis is from 1 to 50,
It is characterized by an average molecular weight of 100,000 or less and 10,000 or more. Gelatin, which has been frequently used as a protective colloid for silver halide emulsion grains, is a degradation product of collagen, which is a linear protein. Collagen has a major axis of 2810 ° and a minor axis of 15 °, Its long axis / short axis ratio is 192 and its average molecular weight is 280,000, which characterizes it as a typical linear protein. J.Phys.Che
As described in m. 68, No. 10, pp. 3009, 1964, a gelatin polymer, which is a linear protein, is adsorbed like a worm by a so-called "Loop and Bridge" model, thereby forming a silver halide. An adsorption layer having a certain thickness is formed on the particle surface. The adsorption layer having this thickness prevents the silver halide grains from approaching each other, thereby preventing the attraction of the London Van der Waals between the grains and preventing the silver halide grains from aggregating. It is possible to maintain the dispersion state of silver halide particles.

The present inventors have conducted intensive studies on the characteristics of globular proteins in the preparation of silver halide grain emulsions, and as a result, discovered the unique properties of globular proteins that are completely different from the linear proteins represented by gelatin. It has been invented that this can be effectively used for forming silver halide grains. That is, the linear protein, gelatin, acts to prevent aggregation of the grains by adsorbing to form an adsorptive layer, but the spherical protein of the present invention surprisingly It promotes agglomeration by adsorbing on particles, rather by attracting particles.

The number of nuclei of tabular grains is governed by the probability of twinning in the formation of nucleus fine grains, which is determined by the probability of aggregation of the fine grains generated during the formation of nucleus fine grains.
Imag. Sci. 39, 323 (1995) and Imag.
42, p. 487 (1998). That is, the number of nuclei of the tabular grains or the type thereof (the number of twin planes, the side structure of the tabular grains) is determined by the twin formation probability. The globular protein of the present invention can increase the probability of aggregation in the formation of nuclear fine particles, and thus increase the probability of twin formation. The factors that increase the twin formation probability in nucleus fine particle formation are well known so far, and particularly the supersaturation degree during nucleation is a very large factor, and it is disclosed that nucleus fine particles are formed at a high supersaturation degree. I have. For example, European Patent No. 610796 discloses that by forming nucleus fine particles in tabular grain nucleation in a short time,
No. 11670 discloses that nucleus particle formation is performed at a high degree of supersaturation by performing nucleus particle formation at a low temperature of 5 to 38 ° C. A high degree of supersaturation is essential for nucleus particle formation. Things are well known in the art.

However, a high degree of supersaturation inevitably results in non-uniform silver ion and halide ion concentrations in a reaction vessel or a mixer due to insufficient stirring capacity, making it difficult to form uniform core fine particles. To If the globular protein of the present invention is present in the formation of nuclear fine particles, a high twin formation probability can be realized even at a low degree of supersaturation, and it is possible to form nuclear fine particles having many twin particles even at a low supersaturation degree. If the degree of supersaturation can be reduced, the concentration distribution in the reaction vessel becomes more uniform by stirring, and uniform nuclear fine particles can be formed. By subsequently aging and growing the core fine particles obtained by the present invention, monodisperse tabular grains having a smaller size distribution can be formed. In the present invention, the amount of the spherical protein to be added is 0.005 g / mol of silver of the tabular grain emulsion obtained by growth.
10 g, preferably 0.01 g to 1 g. The amount of the spherical protein to be added during the formation of the core fine particles is 1 to 100 g, preferably 3 g to 1 mol per mol of silver of the core fine particle emulsion.
50 g. In forming the core fine particles of the present invention, a protective colloid such as gelatin is used in combination. The use ratio of the globular protein / protective colloid of the present invention is 1/1 to 1/50 by weight.
0, preferably 1/5 to 1/100.

Japanese Patent Application Laid-Open No. 11-271898 discloses a static mixer having no stirrer provided outside a reaction vessel and forming core fine particles having a twin ratio as low as possible and forming the fine particles into a protective colloid. A method for producing a silver halide emulsion characterized by causing crystal growth by adding it to a reaction vessel having an aqueous solution is disclosed, and a hydrophilic colloid other than gelatin that can be used as a protective colloid in the text of the patent is disclosed. Are described as proteins such as albumin and casein, but in the examples, only gelatin is used. In the patent, the present invention aims to form fine particles having a twin ratio as small as possible and to grow the particles using the fine particles, and to increase the probability of twin formation to realize uniform tabular grain nucleation. Is completely different.

In preparing the core fine particles of the present invention, instead of adding a silver nitrate aqueous solution and a halide aqueous solution to a reaction vessel holding a protective colloid aqueous solution, a silver nitrate aqueous solution and a halide aqueous solution are placed in a mixer provided outside the reaction vessel. The aqueous solution, the protective colloid solution and the spherical protein solution of the present invention are continuously added, and core fine particles are formed in a mixer. The core fine particles are introduced into a reaction vessel. It is preferable to form a tabular nucleus by physical ripening in a medium and then grow to prepare a photographic emulsion composed of tabular grains.
The globular protein may be added alone, or may be contained in any of a silver nitrate aqueous solution, a halide aqueous solution, and a protective colloid solution. Regarding this nucleation method, Japanese Patent Publication No. 7-8220
No. 8. As the mixer used in the present invention, US Pat.
-239787, 11-76783, Tokuto 268
No. 7183, JP-T-6-5072555.

The formation of fine core particles in the mixer of the present invention is 40%.
It is preferable to carry out at a temperature of not more than ℃. If the core fine particles are formed at a temperature higher than this, ripening occurs immediately after the core fine particles are formed, and the uniformity of the core fine particles is lost. The temperature at which the core fine particles are formed in the mixer is more preferably 30 ° C.
Hereinafter, the temperature is more preferably 20 ° C or lower (preferably 5 ° C or higher).

In the present invention, the general formulas (I) and (II) preferably used for forming (111) main surface type tabular grains are used.
Alternatively, the compound represented by (III) will be described in detail. In the general formula (I), R ₁ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms (for example, methyl group, ethyl group, isopropyl group, t-butyl group, n-octyl group, n-decyl) Group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group),
An alkenyl group having 2 to 20 carbon atoms (for example, allyl group, 2
-Butenyl group, 3-pentenyl group) and an aralkyl group having 7 to 20 carbon atoms (e.g., benzyl group, phenethyl group) are preferable. Each group represented by R ₁ may be substituted. Examples of the substituent include substitutable groups represented by the following R _{2 to} R ₆ .

R ₂ , R ₃ , R ₄ , R ₅ and R ₆ may be the same or different and each represent a hydrogen atom or a substitutable group. Substitutable groups include the following. Halogen atom, alkyl group, alkenyl group, arakinyl group, aralkyl group, aryl group, heterocyclic group (for example, pyridyl group, furyl group, imidazolyl group, piperidyl group, morpholino group, etc.), alkoxy group,
Aryloxy, amino, acylamino, ureido, urethane, sulfonylamino, sulfamoyl, carbamoyl, sulfonyl, sulfinyl, alkyloxycarbonyl, acyl, acyloxy, phosphoramide, alkylthio , An arylthio group, a cyano group, a sulfo group, a carboxy group, a hydroxy group, a phosphono group, a nitro group, a sulfino group, an ammonio group (for example, a trimethylammonio group, etc.), a phosphonio group, a hydrazino group, and the like. These groups may be further substituted. R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , R
₄ and R ₆ may be fused to form a quinoline ring, isoquinoline ring, acridine ring or the like. X ^- represents a counter anion.
Examples of the counter anion include a halogen ion (a chloride ion and a bromine ion), a nitrate ion, a sulfate ion, a p-toluenesulfonic acid ion, and a trifluoromethanesulfonic acid ion. In the general formula (I), preferably, R ₁ represents an aralkyl group, and R ₂ , R ₃ , R ₄ , R
_At least one of ₅ and R ₆ represents an aryl group.
More preferably, in the general formula (I), R ₁ represents an aralkyl group, R ₄ represents an aryl group, and X ⁻ represents a halogen ion. Examples of these compounds are described in JP-A-8-22.
No. 7117 (Japanese Patent Application No. 7-146891) describes crystal habit control agents 1 to 29, but the present invention is not limited thereto.

Next, the general formulas (II) and (II) used in the present invention
The compound (I) will be described in detail. A ₁ , A ₂ ,
A ₃ and A ₄ represent a group of nonmetallic elements for completing a nitrogen-containing hetero ring, and may contain an oxygen atom, a nitrogen atom, and a sulfur atom, and a benzene ring may be condensed.
The hetero ring composed of A ₁ , A ₂ , A ₃ and A ₄ may have a substituent, and each may be the same or different. As the substituent, an alkyl group, an aryl group,
Aralkyl, alkenyl, halogen, acyl, alkoxycarbonyl, aryloxycarbonyl, sulfo, carboxy, hydroxy, alkoxy, aryloxy, amide, sulfamoyl, carbamoyl, ureido, amino Group, a sulfonyl group, a cyano group, a nitro group, a mercapto group, an alkylthio group, or an arylthio group. Preferred examples of the nitrogen-containing hetero ring include a 5- to 6-membered ring (for example, a pyridine ring, an imidazole ring, a thiazole ring, an oxazole ring, a pyrazine ring, a pyrimidine ring, and the like). A more preferred example is a pyridine ring. B represents a divalent linking group. Divalent linking groups include alkylene, arylene, alkenyl, -SO ₂
-, - SO -, - O -, - S -, - CO -, - N (R 2) - (R
₂ represents an alkyl group, an aryl group, or a hydrogen atom. ) Alone or in combination. Preferred examples of B include alkylene and alkenylene. R ₁ and R ₂ are preferably an alkyl group having 1 to 20 carbon atoms. R ₁ and R ₂ may be the same or different. The alkyl group represents a substituted or unsubstituted alkyl group, and examples of the substituent include A ₁ , A ₂ , A ₃
And the same substituents as the substituents for A ₄ . As a preferred example, R ₁ and R ₂ each represent an alkyl group having 4 to 10 carbon atoms. A more preferred example is a substituted or unsubstituted aryl-substituted alkyl group. X represents an anion. For example, they represent chlorine ion, bromine ion, iodine ion, nitrate ion, sulfate ion, p-toluenesulfonate, and oxalate. n represents 0, 1 or 2, and in the case of an internal salt, n is 0 or 1. Specific examples of the compound represented by the formula (II) or (III) are disclosed in JP-A-2-32 (Compound Examples 1 to 42), but the present invention is limited to these compounds. Not something.

The compound represented by formula (I), (II) or (III) preferably used in the present invention has a remarkable property of selectively adsorbing to the (111) plane of silver halide crystals.
This is called a (111) crystal habit modifier. When these compounds are present in the formation of (111) main surface type tabular grains, the compound selectively adsorbs to the main surface of the tabular grains to suppress the growth of the tabular grains in the thickness direction, and as a result, thin tabular grains are formed. You can get it. Japanese Patent Application Laid-Open No. 10-104769 discloses that during nucleation (twinning), thinner tabular grains are prepared using a (111) crystal phase controlling agent. (1
11) The crystal habit controlling agent is preferably not present at the time of forming the core fine particles, but is present only at the time of ripening and growth. More specifically, the (111) crystal habit-controlling agent is added after the completion of the formation of the core fine particles, or is added during the subsequent ripening. Further, the (111) crystal phase controlling agent is also present during the growth of tabular grains, and it is preferable to add the (111) crystal phase controlling agent before the start of growth or during the growth, if necessary. More preferably, the (111) crystal phase controlling agent is added continuously during tabular grain growth. More preferably, the control agent is preferably added continuously in an amount proportional to the increase in the surface area of the particles during the growth of the particles.

The general formula (I), (II) or (I)
The amount of the compound represented by II) is 5 × 10 ^-4 to 10 ^-1 mol per mol of silver halide, and especially 10 ^-3.
It is preferably about 5 × 10 ^-2 mol.

The protective colloid solution used in preparing the tabular grain emulsion of the present invention preferably uses gelatin. The gelatin used in the present invention may be either alkali-treated or acid-treated, but usually alkali-treated gelatin is often used. In particular, it is preferable to use alkali-treated gelatin that has been subjected to deionization treatment or ultrafiltration treatment in which impurity ions and impurities have been removed. In addition to alkali-treated gelatin, acid-treated gelatin, phthalated gelatin obtained by substituting amino groups of gelatin, ambered gelatin, trimellit gelatin, phenylcarbamyl gelatin, aliphatic hydrocarbons having 4 to 16 carbon atoms, and carboxyl groups of gelatin Derivative gelatins such as esterified gelatins substituted with, low molecular weight gelatins (specific molecular weights of 1,000 to 80,000, specific examples include gelatin decomposed by enzymes, gelatin hydrolyzed by acids and / or alkalis, and gelatin decomposed by heat. Can do things),
High molecular weight gelatin (molecular weight of 110,000 to 300,000), gelatin having a methionine content of 50 μmol / g or less, gelatin having a tyrosine content of 30 μmol / g or less, oxidized gelatin,
Gelatin in which methionine has been inactivated by alkylation can be used, or a mixture of two or more thereof can be used. The high-molecular-weight lime-processed ossein gelatin is disclosed in JP-A-11-237704. In the present invention, the amount of gelatin used in the grain forming step is 1 to 60 g / mole of silver, preferably 3 to 40 g. The concentration of gelatin in the chemical sensitization step of the present invention is preferably 1 to 100 g / silver mole, and more preferably 1 to 70 g / silver mole. Gelatin biochemically synthesized by yeast or the like disclosed in US Pat. No. 5,580,712 can also be used.

In producing a silver halide emulsion according to the present invention, there is no particular limitation on additives which can be added from the time of grain formation to the time of coating. Also, combinations with all known techniques can be used. Regarding these, the description in the following literature can be referred to.
A silver halide solvent can be used to promote growth during the crystal formation process and to effectively make chemical sensitization effective during grain formation and / or chemical sensitization. Examples of frequently used silver halide solvents include water-soluble thiocyanates, ammonia, thioethers and thioureas. For example, thiocyanates (U.S. Pat. Nos. 2,222,264, 2,448,534, and 33)
20069), ammonia, thioether compounds (for example, US Pat. Nos. 3,271,157 and 357)
No. 4628, No. 3704130, No. 4297439
No. 4,276,347), thione compounds (for example, JP-A-53-144319, JP-A-53-824).
08, 55-77737, etc.), amine compounds (for example, JP-A-54-100717).
Thiourea derivatives (for example, JP-A-55-2982), imidazoles (JP-A-54-100717), substituted mercaptotetrazole (JP-A-57-2082)
2531) and the like.

For the production of the silver halide emulsion used in the present invention, any of the methods known so far can be used. That is, a silver salt aqueous solution and a halogen salt aqueous solution are added to a reaction vessel having an aqueous gelatin solution with efficient stirring. As a specific method, P. Glafkides
By Chemie et Phisique Photographique (Paul Montel
Published by GFDuffin, Photographic Emulsion
Chemistry (The Focal Press, 1966), VLZeli
Making and Coating Photographic Emuls by kman et al
ion (The Focal Press, 1964) and the like. That is, the acid method,
Any of a neutral method, an ammonia method, and the like may be used, and a method of reacting a soluble silver salt with a soluble halogen salt may be any of a one-side mixing method, a double-mixing method, and a combination thereof. One type of the double jet method is to maintain a constant pAg in the liquid phase in which silver halide is formed,
That is, a so-called controlled double jet method can be used. Also, British Patent 153,016
No., JP-B-48-36890, JP-B-52-163
No. 64,464, etc., a method of changing the addition rate of silver nitrate or an aqueous solution of an alkali halide in accordance with the grain growth rate, US Pat. No. 4,242,445, JP-A-55-158124, etc. It is preferred that the growth be carried out quickly within a range not exceeding the critical supersaturation using the method of changing the concentration of the aqueous solution as described in (1). These methods are preferably used because they do not cause renucleation and the silver halide grains grow uniformly.

Instead of adding a silver salt solution and a halide solution to the reaction vessel, fine particles prepared in advance are added to the reaction vessel to cause nucleation and / or grain growth to obtain silver halide grains. Preferably, a method is used. This technique is disclosed in JP-A-1-183644 and JP-A-1-183645, and U.S. Pat.
8, JP-A-2-44335, JP-A-2-43
534 and JP-A-2-43535. According to this method, the distribution of halogen ions in the emulsion grain crystals can be made completely uniform, and favorable photographic characteristics can be obtained. Further, in the present invention,
Emulsion grains having various structures can be used. So-called core / shell double-structure particles comprising the inside (core) and the outside (shell) of the particles,
For example, a triple structure particle as disclosed in Japanese Patent Application No. 22844 or a multilayer structure particle having a larger structure may be used. When a structure is provided inside the emulsion grains, not only the above-described wrapping structure but also a grain having a so-called junction structure can be produced. These examples are disclosed in JP-A-59-133540.
JP-A-58-108526, European Patent 19
No. 9290A2, JP-B-58-24772, JP-A-59-16254, and the like.
The crystal to be bonded can be formed by bonding to the edge, corner, or face of the host crystal with a composition different from that of the host crystal. Such a junction crystal can be formed even if the host crystal is uniform in halogen composition or has a core-shell structure. In the case of a joint structure, a combination of silver halides is of course possible, but if a silver salt compound having a non-rock salt structure such as silver silver or silver carbonate can be combined with silver halide to form a joint structure, it is used. You may.

In the case of silver iodobromide particles having these structures, for example, in core-shell type particles, even if the silver iodide content in the core portion is high and the silver iodide content in the shell portion is low, Conversely, grains having a low silver iodide content in the core portion and a high silver iodide content in the shell portion may be used. Similarly, particles having a bonding structure may be particles having a high silver iodide content in the host crystal and a relatively low silver iodide content in the bonding crystal, or vice versa. Also,
The boundary portions having different halogen compositions in the grains having these structures may be clear boundaries, or may be unclear boundaries due to the formation of a mixed crystal due to a composition difference. It may have a structural change. The silver halide emulsion used in the present invention is described in EP-0097727B1, EP
-006412B1 A treatment for imparting roundness to particles as disclosed in each specification, or DE-23.
The surface may be modified as disclosed in the specification of JP 0664747 C2 and JP-A-60-221320.

As the chemical sensitization in the present invention, chalcogen sensitization such as sulfur sensitization, selenium sensitization, and tellurium sensitization, and noble metal sensitization and reduction sensitization can be used alone or in combination.

In the sulfur sensitization, an unstable sulfur compound is used, and P. Grafkides, Chimie et Physique Photograph
ique (Paul Momtel, 1987, 5th edition), Research
Unstable sulfur compounds described in Disclosure 307, 307105 and the like can be used. Specifically, thiosulfates (eg, hypo), thioureas (eg, diphenylthiourea, triethylthiourea, N-
Ethyl-N ′-(4-methyl-2-thiazolyl) thiourea, carboxymethyltrimethylthiourea), thioamides (eg, thioacetamide), rhodanines (eg, diethyl rhodanine, 5-benzylidene-N-ethyl-) Rhodanine), phosphine sulfides (eg, trimethylphosphine sulfide), thiohydantoins, 4-oxo-oxazolidine-2-thiones, dipolysulfides (eg, dimorpholine disulfide, cystine, hexathiocan-thione), mercapto Known sulfur compounds such as compounds (for example, cysteine), polythionates, elemental sulfur, and active gelatin can also be used.

In the selenium sensitization, an unstable selenium compound is used, and JP-B-43-13489 and JP-B-44-157.
No. 48, JP-A-4-25832, JP-A-4-109240
And labile selenium compounds described in Japanese Patent Application Nos. 3-53693 and 3-82929 can be used. Specifically, colloidal metal selenium, selenoureas (eg, N, N-dimethylselenourea, trifluoromethylcarbonyl-trimethylselenourea, acetyl-trimethylselenourea), selenoamides (eg, selenoacetamide, N, N-diethylphenylselenoamide), phosphine selenides (eg, triphenylphosphine selenide, pentafluorophenyl-triphenylphosphine selenide), selenophosphates (eg, tri-p-tolylselenophosphate) , Tri-n-butylselenophosphate), selenoketones (eg, selenobenzophenone), isoselenocyanates, selenocarboxylic acids,
Selenoesters and diacylselenides may be used. Furthermore, Japanese Patent Publication No. 46-4553 and 52-3
Non-labile selenium compounds described in 4492 publications and the like,
For example, selenous acid, potassium selenocyanide, selenazoles, selenides and the like can be used.

In tellurium sensitization, an unstable tellurium compound is used, and Canadian Patent 800958, British Patent 129
Nos. 5462 and 1396696, Japanese Patent Application No.
333819, 3-53693, 3-1315
Unstable tellurium compounds described in JP-A Nos. 98 and 4-129787 can be used. Specifically, telluroureas (e.g., tetramethyltellurourea, N, N'-dimethylethylenetellurourea, N, N '
-Diphenylethylene tellurourea), phosphine tellurides (eg, butyl-diisopropylphosphine telluride, tributylphosphine telluride, tributoxyphosphine telluride, ethoxy-diphenylphosphine telluride), diacyl (di) telluride (For example, bis (diphenylcarbamoyl) ditelluride, bis (N-phenyl-N-methylcarbamoyl) ditelluride, bis (N-phenyl-N-methylcarbamoyl) telluride, bis (ethoxycarbonyl) telluride), isotellurocyanates, Telluramides, tellurohydrazides, telluroesters (eg, butylhexyltelluroester), telluroketones (eg, telluroacetophenone), colloidal tellurium, (di) tellurides, and other tellurium compounds Potassium nitrosium telluride, tellurocarbonyl penta isethionate sodium salt) or the like may be used.

Noble metal sensitization is described in P. Grafkide, supra.
s, Chimie et Physique Photographique (Paul Momt
el company, 1987, 5th edition), Research Disclosure 3
Gold, platinum, and the like described in Vol.
Noble metal salts such as palladium and iridium can be used, and gold sensitization is particularly preferable. Specifically, in addition to chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, and gold selenide, U.S. Patent Nos. 2642361, 5049484, and 50494
The gold compounds described in the specification of No. 85 can also be used. For reduction sensitization, see P. Grafkides, Ch.
imie et Physique Photographique (Paul Momtel,
1987, 5th edition), Research Disclosure 307, 3
Known reducing compounds described in No. 07105 or the like can be used. Specifically, aminoiminomethanesulfinic acid (also called thiourea dioxide), borane compound (for example, dimethylamine borane), hydrazine compound (for example, hydrazine, p-tolylhydrazine), polyamine compound (for example, diethylenetriamine, triethylene Tetramine), stannous chloride, silane compounds,
Reductones (eg, ascorbic acid), sulfites,
An aldehyde compound, hydrogen gas, or the like may be used. The reduction sensitization may be performed in an atmosphere having a high pH or an excess of silver ions (so-called silver ripening).

These chemical sensitizations may be used alone or in combination of two or more. When combined, a combination of chalcogen sensitization and gold sensitization is particularly preferable. Further, reduction sensitization is preferably performed at the time of forming silver halide grains. The amount of the chalcogen sensitizer used in the present invention varies depending on the silver halide grains to be used, the chemical sensitization conditions, and the like, but is 10 ^-8 to 10 ^-2 mol, preferably 1 to 10 mol, per mol of silver halide.
About 0 ^{-7 to} 5 × 10 ^-3 mol is used. The amount of the noble metal sensitizer used in the present invention is 1 to 1 mol of silver halide.
About 0 ^-7 to 10 ^-2 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pAg is 6 to 1
1, preferably 7 to 10 and a pH of 4 to 10
Preferably, the temperature is 40 to 95 ° C, and more preferably 4 to 95 ° C.
5-85 ° C is preferred.

[0045]

EXAMPLES The present invention will be described below in more detail, but the present invention is not limited thereto. Example 1 Preparation of silver bromide tabular grains In this example, in the system disclosed in FIG. 2 of JP-A-10-239787, the mixing device disclosed in FIG. Using 5 cc), tabular grains were prepared as follows. In this embodiment, a method of performing both nucleation and particle growth using a mixer will be described. Emulsion 1-A (Comparative) Nothing was present in the reaction vessel 1 shown in FIG. 2 of the publication, and the outer wall of the vessel was kept at 35 ° C. 500 cc of a 0.021M silver nitrate aqueous solution and 500 cc of a 0.028M KBr aqueous solution containing 0.8% by weight of low molecular weight gelatin were added to the mixer shown in FIG. 1 for 20 minutes, and the resulting nuclear emulsion was continuously added. Was added to the reaction vessel. At this time, the stirring rotation speed of the mixer was 20
00 rpm. (Formation of core fine particles) 10% bone gelatin solution 3 in which amino groups are 95% phthalated
After adding 00 cc and KBr to adjust the pBr of the emulsion in the reaction vessel to 2.1, the temperature was raised to 75 ° C. and left for 5 minutes. (Formation of tabular grain nuclei by aging) Then, 600 cc of a 1.0 M silver nitrate aqueous solution was again added to the mixer.
Then, 600 cc of KBr of 1.02 M KBr and 800 cc of a 5% aqueous solution of low molecular weight gelatin were added at a constant flow rate over 60 minutes. The fine grain emulsion produced in the mixer was continuously added to the reaction vessel. At this time, the stirring rotation speed of the mixer was 200
It was 0 rpm. (Grain growth) At the time when silver nitrate was added at 70% during grain growth, IrCl ₆ was added at 8 × 10 ⁻⁸ mol / mol Ag and doped. Further, a yellow blood salt solution was added to the mixer before the end of the particle growth. The yellow blood salt was doped into 3% (in terms of the amount of added silver) of the shell portion of the particles so that the local concentration was 3 × 10 ⁻⁴ mol / mol Ag. After completion of the addition, the emulsion was cooled to 35 ° C., washed with ordinary flocculation, and 70 g of lime-processed bone gelatin was added and dissolved. The pAg was adjusted to 8.7, the pH was adjusted to 6.5, and the mixture was stored in a cool dark place. . Table 1 shows the characteristics of the tabular grains obtained.

Emulsion 1-B (Comparative) Emulsion 1-A was carried out in the same manner as in Emulsion 1-A, except that the formation of fine nuclei was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
500cc aqueous solution of 0.09M KBr containing 0.1% by weight
Was continuously added for 20 minutes, and the resulting emulsion was continuously placed in a reaction vessel over 20 minutes to obtain a 1000 cc nuclear fine particle emulsion.

Emulsion 1-C (Invention) Emulsion 1-A was carried out in the same manner as in Emulsion 1-A, except that the formation of fine nuclei was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
0.1% by weight and lysozyme (egg white) 0.0
500cc of a 0.009M KBr aqueous solution containing 12% by weight was continuously added for 20 minutes, and the obtained emulsion was continuously placed in a reaction vessel over 20 minutes to obtain a 1000cc nuclear fine particle emulsion. Emulsion 1-D (Invention) Emulsion 1-A was carried out in the same manner as Emulsion 1-A, except that the formation of fine core particles was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
500 cc of a 0.09 M aqueous KBr solution containing 0.1% by weight and 0.1% by weight of casein (milk) was continuously added for 20 minutes, and the obtained emulsion was continuously placed in a reaction vessel for 20 minutes. Then, a 1000 cc nuclear fine particle emulsion was obtained.

Emulsion 1-E (Invention) Emulsion 1-A was carried out in the same manner as in Emulsion 1-A, except that the formation of fine nuclei was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
0.1% by weight and albumin (egg white) at 0.0
500cc of a 0.009M KBr aqueous solution containing 5% by weight was continuously added for 20 minutes, and the resulting emulsion was continuously placed in a reaction vessel over 20 minutes to obtain a 1000cc nuclear fine particle emulsion. Emulsion 1-F (Invention) Emulsion 1-A was carried out in the same manner as in Emulsion 1-A, except that the formation of fine core particles was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
A 0.009 M aqueous KBr solution containing 0.1% by weight and 0.05% by weight of hemoglobin (bovine blood) 500
cc were continuously added for 20 minutes, and the obtained emulsion was continuously placed in a reaction vessel over 20 minutes to obtain a 1000 cc nuclear fine particle emulsion.

[0049]

[Table 1]

* In this experiment 1-B, tabular grains were formed because the concentration of silver nitrate and halide solution added in the formation of nucleus fine grains was reduced, and the degree of supersaturation and the amount of silver halide formed during the formation of nucleus fine grains were reduced. The number of nuclei decreased, so that the fine particles added from the mixer during the growth could not be completely dissolved in the reaction vessel,
Many fine particles have remained. Excluding the fine particles, the tabular grain ratio was 95%.

As shown in Table 1, when the concentration of silver nitrate and KBr to be added at the time of forming fine nuclei is reduced to reduce the degree of supersaturation at the time of forming fine nuclei in the present invention, the number of tabular grain nuclei is reduced. However, at that time, when a globular protein was present at the time of nucleation, the number of nuclei of tabular grains increased due to an increase in the twin formation probability even at a low degree of supersaturation, and tabular grains having a narrow size distribution were obtained. Example 2 Tabular grain silver iodobromide emulsion Emulsion 2-A (Comparison) In the same system as the system shown in FIG. 3 of JP-A-2-213837, the mixer shown in FIG. 0.5 cc) was used to prepare tabular grains as described below. In this embodiment, a method is shown in which both the formation of fine particles and the growth of particles are performed by a mixer. In mixer 7, add 0.0
0.028M K containing 500 cc of 21M silver nitrate aqueous solution and 0.1% by weight of low molecular weight gelatin (average molecular weight 40,000)
500 cc of an aqueous Br solution was added continuously for 25 minutes, and the resulting emulsion was continuously placed in a reaction vessel for 25 minutes.
A nuclear emulsion of 00 cc was obtained. At that time, the stirring rotation speed of the mixer was 2
000 rpm. (Formation of core fine particles) After the formation of core fine particles, while stirring the nuclear emulsion in the reaction vessel well, 22 cc of a 0.8 M KBr solution and 10% by weight of trimellit containing 0.2 mmol of crystal habit controlling agent 1 were added. 300 cc of gelatin was added, the temperature was raised to 75 ° C., and the mixture was left for 5 minutes. (Tubular grain nucleation by aging)

Thereafter, 1000 cc of a 0.6 M silver nitrate aqueous solution and low-molecular-weight gelatin (average molecular weight: 4
Was added at a constant flow rate over a period of 56 minutes. The fine grain emulsion produced in the mixer was continuously added to the reaction vessel. At that time, the stirring rotation speed of the mixer was 2000 rpm. At the same time, 150 cc of 1/50 M solution of crystal habit controlling agent 1
Was continuously added to the reaction vessel at a constant flow rate. The stirring blade of the reaction vessel was rotated at 800 rpm and was well stirred. (Growth) During grain growth, IrCl ₆ was added at 8 × 10 ⁻⁸ mol / mol Ag at the time when 70% of silver nitrate was added, and doped. Further, a yellow blood salt solution was added to the mixer before the end of the particle growth. The yellow blood salt was doped into 3% (in terms of the amount of added silver) of the shell portion of the particles so that the local concentration was 3 × 10 ⁻⁴ mol / mol Ag. After completion of the addition, the emulsion was cooled to 35 ° C., washed with ordinary flocculation, and 70 g of lime-processed bone gelatin was added and dissolved. The pAg was adjusted to 8.7, the pH was adjusted to 6.5, and the mixture was stored in a cool dark place. . Table 2 shows the properties of the obtained tabular grains. Crystal phase control agent 1

[0053]

Embedded image

Emulsion 2-B (Comparative) The same procedure as in Emulsion 2-A was conducted, except that the formation of fine nuclei was changed as follows. In the formation of the core fine particles, the mixer is charged with 0.1%.
500 cc of a 0029 M silver nitrate aqueous solution and 500 cc of a 0.09 M KBr aqueous solution containing 0.1% by weight of low molecular weight gelatin (average molecular weight: 40,000) are continuously added for 25 minutes, and the obtained emulsion is continuously placed in a reaction vessel. Take 25 minutes, 1
A 000 cc nuclear fine grain emulsion was obtained. Emulsion 2-C (Invention) Emulsion 2-A was carried out in the same manner as in Emulsion 2-A, except that the formation of fine core particles was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
0.1% by weight and lysozyme (egg white) 0.0
500 cc of a 0.09 M aqueous KBr solution containing 20% by weight was continuously added for 25 minutes, and the resulting emulsion was continuously placed in a reaction vessel over 20 minutes to obtain a 1,000 cc nuclear fine particle emulsion. Emulsion 2-D (invention) Emulsion 2-D was carried out in the same manner as Emulsion 2-A, except that the formation of fine core particles was changed as follows. 500cc of a 0.0029M silver nitrate aqueous solution and low molecular weight gelatin (average molecular weight 40,000)
500 cc of a 0.09 M aqueous KBr solution containing 0.1% by weight and 0.1% by weight of casein (milk) is continuously added for 25 minutes, and the obtained emulsion is continuously placed in a reaction vessel for 20 minutes. Then, a 1000 cc nuclear fine particle emulsion was obtained.

[0055]

[Table 2]

* In the experiment 1-B, the concentration of the silver nitrate and halide solutions added in forming the core fine grains was reduced, so that the supersaturation and the amount of silver halide formed during the formation of the core fine grains were reduced. The number of nuclei decreased, so that the fine particles added from the mixer during the growth could not be completely dissolved in the reaction vessel,
Many fine particles have remained. Excluding the fine particles, the tabular grain ratio was 96%.

As shown in Table 2, when the concentration of silver nitrate and KBr added at the time of forming the nucleus fine particles was reduced to reduce the supersaturation degree at the time of forming the nuclei fine particles according to the present invention, the number of tabular grain nuclei decreased. Thus, the size can be increased, but the size distribution can be reduced. However, the fine particles added during the growth cannot be completely dissolved and the fine particles remain. If the spherical protein is present at the time of forming the core fine particles, tabular grains having a narrow size distribution after growth can be obtained without reducing the number of tabular grains even under low supersaturation.

Example 3 The emulsion 2-C of Example 2 was optimally chemically and spectrally sensitized,
It was used as an emulsion for the third layer of sample 201 of Example 2 of JP-A-9-146237, and was subjected to the same treatment as that of the example of JP-A-9-146237 to obtain good results. Further, the emulsion 2-C was optimally subjected to chemical sensitization and spectral sensitization, and was used as an emulsion for the third layer of the sample 110 of Example 2 of JP-A-10-20462, and processed in the same manner as in the example of JP-A-10-20462. And obtained good results. Emulsion 2-C was optimally chemically sensitized and spectrally sensitized and used as an emulsion for the third layer of sample 201 of Example 2 of JP-A-9-146237, and processed in the same manner as in the example of JP-A-9-146237. And obtained good results.

[0059]

As shown in the Examples, a tabular grain silver halide photographic emulsion having a high aspect ratio and a narrow grain size distribution was obtained by the production method of the present invention.

Claims (6)

[Claims] 1. A process for producing tabular silver halide emulsions by forming tabular grain nuclei by forming nucleus fine grains and subsequent ripening, thereby producing spherical proteins during the production of tabular silver halide emulsions. And producing a tabular silver halide photographic emulsion. 2. A mixer is provided outside a reaction vessel in which silver halide grains grow, and an aqueous solution of silver nitrate and an aqueous solution of a water-soluble halide are continuously supplied to the mixer, and the two are mixed. By forming core fine particles, supplying the core fine particles to the reaction vessel, and aging the core fine particles in the reaction vessel, a tabular grain nucleus is formed, and the tabular grain nucleus is grown to form a flat plate. A method for producing a silver halide photographic emulsion, characterized in that a spherical protein is present at the time of forming the fine core particles, wherein a spherical protein is present. 3. The method for producing a tabular silver halide photographic emulsion according to claim 2, wherein the fine core particles formed by the mixer are immediately supplied to the reaction vessel. 4. The method according to claim 1, wherein the step of supplying the core fine particles formed by the mixer to the reaction vessel is performed for 5 minutes or more, and the nucleation of the tabular grains is performed by aging in the reaction vessel. 3. The method for producing a tabular silver halide photographic emulsion according to item 2. 5. The tabular silver halide photographic emulsion according to claim 1, wherein the globular protein has a major axis of 500 ° or less, a minor axis of 100 ° or less, and an average molecular weight of 100,000 or less. Manufacturing method. 6. A nucleus of tabular grains formed by nucleation and aging of fine grains.
Of silver halide tabular grain emulsions
In the manufacturing method, the following general formulas (I), (II) and (II)
At least one compound selected from the compounds represented by I)
Not present during nucleation, during ripening and / or during growth
6. The silver halide according to claim 1, which is present.
Emulsion manufacturing method. Embedded image(Where R₁ Is an alkyl group, alkenyl group, aralkyl
R represents a group_Two , R_Three, R_Four , R_Five And R₆ Haso
Each represents a hydrogen atom or a substituent. R_Two And R _Three , R
_Three And R_Four , R_Four And R_Five , R_Five And R₆ Is fused
Good. Where R_Two , R_Three , R_Four , R_Five And R₆ 
At least one represents an aryl group. X^-Is Anio
Represents Embedded image(Where A₁ , A_Two , A_Three And A_Four Is nitrogen-containing
Represents a group of non-metallic atoms to complete the heterocycle,
Each may be the same or different. B is a divalent linking group
Represents m represents 0 or 1. R₁ , R_Two Each
Represents an alkyl group. X represents an anion. n is 0, 1
Or 2 and n is 0 or 1 in the case of an internal salt
You.