JPH05241263A - Silver halide photographic sensitive material and its processing method - Google Patents

Abstract

PURPOSE:To obtain the photosensitive material capable of using a a spectral sensitizing dyestuff having superior spectrally sensitizing characteristics without being limited to the conventional specified spectral sensitizing dyestuffs and comparatively sensitized in grain form and photographic characteristics and resistant to development inhibition, and high in contrast and sensitivity and small in intrinsic desensitization. CONSTITUTION:The photographic sensitive material having on a support a silver halide emulsion layer containing novel silver halide grains in an amount of 50mol% of the total silver halide grains, and these grains are host grains mainly having [111] surfaces and bilayer-or multi-layer silver halide structure and containing surface silver iodide in an amount of <=8mol%, and epitaxial silver salt are selectively joined to the vertices and/or edges of these host grains.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic material, and more specifically, it has a junction type grain shape composed of silver iodobromide, is highly sensitive in its inherent absorption and contains a sensitizing dye. Also relates to a photographic material using a high-sensitivity silver halide emulsion having less intrinsic desensitization and improved spectral sensitivity, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, the demand for silver halide emulsions for photography has become more and more strict, and for color photographic materials and black-and-white photographic materials, low fog and high sensitivity are required not only in the intrinsic absorption region but also in the spectral absorption region. To be done.

Generally, high sensitivity emulsions contain 0 to 1 iodine.
Emulsions consisting of silver halide grains containing 0 mol% are known, which emulsions generally consist of twin or normal grains mainly composed of {111} faces. Here, a normal crystal refers to a grain that does not substantially include twin planes.

However, grains mainly composed of {111} planes have a drawback that the intrinsic desensitization is generally large in spectral sensitization. Techniques for improving these drawbacks are as follows.

As an emulsion having increased latent image forming efficiency and improved intrinsic desensitization by a sensitizing dye, double-structured grains having a silver iodobromide core and a silver bromide shell are available in Bando, Shibahara, Ishimaru's Journal of Imaging Science, 1985, 29
Volume, page 193. However, such a grain is difficult to prevent a part of silver iodide contained in the core from being redissolved and mixed into the shell portion when growing a silver bromide shell on the silver iodobromide of the core. Therefore, there is a problem that development suppression is likely to occur due to iodide ions mixed in the shell.

In JP-A-59-162540, intrinsic desensitization is prevented by selectively depositing a non-isomorphic silver salt such as silver rhodan on a face-centered cubic silver halide host crystal. The possibility is suggested. However, such particles are actually thermodynamically highly unstable systems,
The form of course has a drawback that it is difficult to keep the photographic performance stable. Also, JP-A-59-1335
No. 40 discloses that a site-selective agent is adsorbed on a host grain having an aspect ratio of less than 8: 1 and mainly composed of {111} faces and having a silver iodide content of 15 mol% or less, and a specific surface region of the host crystal is adsorbed. It is disclosed that the composite particles having guest crystals deposited thereon improve the latent image forming efficiency and alleviate the intrinsic desensitization. However, in such particles, the site indicator used for selectively depositing guest crystals is a cyanine dye of a trimethine chain that mainly forms a J-aggregate, and the usable ones are limited, and it is not always spectroscopic. It is not a preferable combination in view of the sensitizing property. Further, other site indicators include adenine and iodide ion. However, it is well known to those skilled in the art that adenine causes inhibition of adsorption of a spectral sensitizing dye, suppression of chemical sensitization, and iodide causes inhibition of development.

Further, JP-A-58-108526 discloses a method of sensitizing a guest crystal by depositing a guest crystal in a specific portion on a tabular grain having an aspect ratio of 8: 1 or more. This publication describes a technique of introducing a guest crystal into a specific site on the principal plane without a site indicator. That is, in order to selectively introduce the guest silver chloride crystal in the plane, a difference in iodide content in the main plane is required. For example, in order to introduce a guest crystal in the center of the main plane, a host containing less than 5 mol% iodide in the central portion of the tabular grains and at least 8 mol% iodide in the peripheral region is used. It is disclosed that the use of crystals can be achieved by selectively introducing an AgCl crystal in a plane without a site indicator. Further, it is also disclosed that a guest crystal is selectively deposited on a side surface other than the main plane of the tabular grain by using a site indicator. However,
In the light-sensitive material using the junction type grains containing guest crystals selectively epitaxially grown on the central plane and side faces of the tabular silver iodobromide grains described in this publication, a sufficiently high contrast cannot be obtained, and the emulsion grains However, the morphology and the photographic performance were unstable.

According to the descriptions of JP-A-59-133540 and JP-A-58-108526, silver chloride is incorporated into the site of silver iodobromide composed of {111} faces having a silver iodide content of 15 mol% or less. If introduced without an indicator, guest silver chloride crystals will deposit at random rather than at selective positions regardless of whether the host crystals are normal crystals or twin crystals.

Berry, Skillman's Journal of Applied Physics (Journa
l of Applied Physics) 35, 2165, 19
According to 1964, guest crystals are randomly deposited on the {111} plane in a pure silver bromide host crystal having a silver iodide content of 0 mol%.

Further, European Patent No. 215612 discloses that the surface area of a particle is increased by roughening the surface of the particle to increase the gain of spectral sensitivity. However, in order to form this grain, the presence of a sensitizing dye is indispensable, and since the sensitizing dye is limited, it is not always a technique that can be generally used, and the prevention of intrinsic desensitization is not always necessary. I can't expect.

[0011]

As described above, the spectral sensitizing dyes having excellent spectral sensitizing properties can be used without being limited to the conventional specific spectral sensitizing dyes, and the particle morphology and the photograph can be obtained. It is difficult to obtain a silver halide photographic emulsion having various characteristics such that the characteristics are relatively stable, development hardly suppressed when used in a photographic material, high contrast, high sensitivity and little intrinsic desensitization. There was a situation.

The present invention aims to solve these problems at the same time.

[0013]

The objects of the present invention are: (1) a photographic material having a silver halide emulsion layer on a support, which mainly has a {111} surface and has a surface composition as a halogen composition structure. The emulsion layer contains silver halide grains in which silver salt epitaxy is selectively bonded to the tops and / or edges of host grains having a double or multiple structure having a silver halide content of 8 mol% or less. A silver halide photographic material characterized by occupying 50% or more of silver halide grains; (2) It has a {111} surface mainly and has a silver iodide content of 8 mol% or less as a halogen composition structure. For double- or multi-structured particles, silver salt epitaxy consisting mainly of silver chloride with a silver potential of a saturated calomel electrode of less than 200 mV is selectively applied to the top and / or edges of the host particles. A method for producing a silver halide photographic material, which comprises bonding and coating the silver halide emulsion thus obtained on a support; and (3) a substantially iodine odor having a high iodine content inside. It is composed of a core part which is silver iodide and a shell part which includes a continuous layer which is substantially silver iodobromide which continuously changes from the inside of the grain toward the surface to a low iodide content. } For a grain having a surface and a surface silver iodide content of 8 mol% or less, the silver potential of a saturated calomel electrode is 200 mV
Below, silver salt epitaxy consisting mainly of silver chloride,
Selectively bonding to the tops and / or edges of the host particles,
It was achieved by a method for producing a silver halide photographic material characterized by coating the silver halide emulsion thus obtained on a support. In the production methods (2) and (3), the silver salt epitaxy consisting mainly of silver chloride can be selectively bonded to the tops and / or edges of the host grains without using a site indicator.

In the present specification, "selectively bonded with silver salt epitaxy" means that silver halide epitaxy is present in silver halide grains of which number is 50% or more, preferably 70% or more in observation of electron micrograph. Of 50% or more, preferably 70% or more, are bonded to the tops and / or edges of the host particles. Hereinafter, the present invention will be described in detail.

The silver iodide content of the host grains is 15 mol% or less of silver iodobromide consisting of {111} faces according to the above-mentioned JP-A-59-133540 and JP-A-58-108526. Is introduced without a site indicator,
The guest silver chloride crystals are said to be joined randomly rather than at selective positions. It is further stated that a site indicator is required in all cases to achieve silver salt epitaxy on selected surface sites of the host grains using host grains with an iodide concentration of 8 mol% or less. ing.

However, the present inventor does not use silver iodobromide having the uniform halogen composition structure disclosed in each of the above publications as a host grain, but rather a grain having a multiple halogen composition structure or a double structure grain. By using host particles,
It has been discovered that guest silver chloride crystals are bonded at selective positions without a site indicator even when the surface silver iodide content is 8 mol% or less.

In the present invention, a silver halide host grain mainly having a {111} surface means that an area larger than 50% of the total surface area of the silver halide host grain is {111}.
It is given by the crystal plane. In many cases, it is preferred that all major crystal faces be {111} crystal faces.

The face ratio of {111} faces can be determined by the Kubelka-Munk dye adsorption method. This is because dyes that are preferentially adsorbed on either the {111} face or the {100} face and in which the association state of the dyes on the {111} face and the association state of the dyes on the {100} face are spectrally different. select. The surface ratio of {111} planes can be determined by adding such a dye to the emulsion and examining the spectral spectrum with respect to the amount of the dye added in detail.

Host particles mainly having {111} crystal faces can be reliably obtained by adjusting pAg during the precipitation formation process. (PAg used here
Is the negative logarithm of silver ion concentration). It is well known that the formation of {100} crystal faces is suitable at high silver ion concentrations (low pAg), and the formation of {111} crystal faces is suitable at low silver ion concentrations (high pAg). {1
The exact pAg at which the formation of 11} crystal planes is obtained varies in principle as a function of the temperature of the halide and precipitation process used. Generally, for silver bromide emulsions with pAg's of about 9.0 or greater and silver bromoiodide emulsions with a limited iodide content, predominantly {111} crystal faces can be obtained.

The halogen structure of the host grain is a double or multiple grain having a surface silver iodide content of 8 mol% or less. The double- or multi-structured grain is a grain having a layer or core portion having a high silver iodide content rate inside the grain and covered with a layer having a low iodine content rate as the outermost shell. Regarding the multi-structure particles, JP-A-62-18
It can be prepared with reference to Japanese Patent No. 7838. The double-structured particles can be prepared with reference to JP-A-60-143331.

In a particularly preferred embodiment of the host grain used in the present invention, the host grain has a core portion which is substantially silver iodobromide having a high iodide content inside, and a portion from the inside to the surface of the grain. Consists of a shell portion including a continuous layer of substantially silver iodobromide that continuously changes to a low iodide content, has a {111} surface mainly, and has a surface silver iodide content of 8 mol% or less. Is a particle.

The core portion is a high iodine silver halide,
The average iodine content is 10 mol% to the solid solubility limit of 40 mol%
It should be between It is preferably 15 to 40%, more preferably 20 to 40% by mole. Usually 20 to
The optimum value of the core average iodine content exists between 35 mol%, but the optimum value may exist in the vicinity of 35 to 40 mol% depending on the preparation method of the emulsion grains. In the core portion, silver halides other than silver iodide consist essentially of silver bromide, and the ratio thereof is preferably very high. The iodine distribution in the core part is preferably uniform.

The continuous layer consists essentially of silver iodobromide whose content changes continuously from the portion in contact with the core portion toward the surface of the continuous layer. The portion in contact with the core portion preferably has the same iodine content as the surface iodine composition of the core portion. A structure in which the iodine content continuously changes from the part in contact with the core to the surface means that the particle radius increases from the part in which the iodine content in contact with the core is highest toward the surface of the continuous layer. This is a structure in which the iodine content decreases linearly with respect to the direction or follows a curve. In the present invention, a linear decrease is preferable, but the inclination is preferably such that a sharp misfit does not occur in the lattice constant, and when it decreases along a curve, a sharp misfit does not occur in the lattice constant as well. It is preferable that the rate of change is a degree. The iodine content on the surface of the continuous layer, which continuously changes from the portion in contact with the core portion toward the surface of the continuous layer, is preferably 8 mol% or less. The silver halide other than silver iodide in the shell portion may be any of silver chloride, silver chlorobromide or silver bromide, but it is preferable that the proportion of silver bromide is high.

Regarding the total halogen composition, the effect of the present invention is remarkable when the silver iodide content is 5 mol% or more. More preferable total silver iodide content is 7 mol%
That is all.

Such an internal halogen composition structure of the silver halide grain of the present invention is an electron microscopic image of a cross section passing through the center of the grain in an ultrathin section cut using a microtome, using an analytical electron microscope. Can be obtained by measuring the halogen composition structure corresponding to. The silver iodide content of the surface layer of the silver halide emulsion can be measured by X-ray photoelectron spectroscopy (XPS). The silver iodide content and the average silver iodide content of each individual silver halide grain are measured by EPMA (Electron-Probe Micro Analyzer).
Method).

The size of the silver halide grains in the present invention is not particularly limited, but is preferably 0.2 μm to 4 μm, more preferably 0.4 μm to 3 μm.

The emulsion of the present invention may have a wide grain size distribution, but an emulsion having a narrow grain size distribution is preferable. Particularly in the case of normal crystal grains, the grain size which accounts for 90% of the total of each emulsion in terms of the weight or the number of grains is within ± 40% of the average grain size, and within ± 30% of the average grain size. Dispersed emulsions are preferred.

The halogen composition of the silver halide guest crystal selectively bonded to the top and / or edge of the host crystal is substantially silver chloride. The term "substantially silver chloride" as used herein means that the chloride content is at least 50 mol% or more, and preferably 75 mol% or more.
% Or more of silver halide. The silver iodide content is preferably 2 mol% or less.

Next, the method for producing the silver halide grains of the present invention will be described.

The formation of bonding particles begins with the preparation of host crystals. The host silver halide emulsion of the present invention can be prepared by selecting from various methods known in the field of silver halide photographic light-sensitive materials and combining them.

The host silver halide emulsion having a multiple structure can be prepared with reference to JP-A-62-187838. Further, regarding a host silver halide emulsion having a double structure, JP-A-60-14333 is used.
It can also be prepared with reference to JP-A-1.

Further, a particularly preferred embodiment of the silver halide host grain of the present invention, a core portion which is substantially silver iodobromide having a high iodine content inside, and a core portion which is continuous from the inside of the grain toward the surface Composed of a shell portion containing a continuous layer of substantially silver iodobromide, which has been changed to a low iodine content, has a {111} surface and has a surface silver iodide content of 8
Preparation of a core particle that is a substantially iodine iodobromide having a high iodine content is less than mol%; and a low iodine content continuously from the inside of the particle to the surface of the core particle. Preparation of a continuous layer of substantially silver iodobromide changing to

Core grains having a high iodine content and substantially silver iodobromide are prepared by a method such as an acid method, a neutral method or an ammonia method, or a one-sided mixing method as a method of reacting a soluble silver salt with a soluble halogen salt. , A simultaneous mixing method, a combination thereof, and the like.

As one form of the simultaneous mixing method, a method of keeping pAg constant in the liquid phase in which silver halide is produced, that is, a control double jet method can be used. As another form of the simultaneous mixing method, a triple jet method (for example, soluble silver salt, soluble bromine salt and soluble iodine salt) in which soluble halogen salts having different compositions are independently added can also be used. When preparing the core, a silver halide solvent such as ammonia, a rhodanate, thioureas, thioethers or amines may be selected and used. An emulsion in which the grain size distribution of core grains is narrow is desirable. Emulsions in which the halogen composition of the individual grains at the core stage, especially the iodine content, are more uniform are desirable.

Whether or not the halogen composition of each grain is uniform can be determined by the above-mentioned X-ray diffraction method and EPMA method. When the halogen composition of the core particles is more uniform, the diffraction width of X-ray diffraction is narrow and gives a sharp peak.

Japanese Examined Patent Publication No. 49-21657 discloses a method for preparing core particles having a uniform halogen composition among particles. One is a double jet method in which 5 g of inert gelatin and 0.2 g of potassium bromide are dissolved in 700 ml of distilled water to prepare a solution, which is stirred at 50 ° C.
52.7 g of potassium bromide and 24.5 g of potassium iodide in an aqueous solution of 1 liter and 100 g of silver nitrate in an aqueous solution of 1 liter were simultaneously added to the previously stirred solution at a constant rate in about 80 minutes. Then, distilled water is added to make the total amount 3 l, and silver iodobromide having a silver iodide content of 25 mol% is obtained.
It has been found by X-ray diffraction that the grains are silver iodobromide grains having a relatively sharp iodine distribution. Another method is the rush addition method, in which 33 g of inert bone gelatin, 5.4 g of potassium bromide and 4.9 g of potassium iodide are added to 50 g of distilled water.
An aqueous solution of 0 ml was stirred at 70 ° C., and 125 ml of an aqueous solution of 12.5 g of silver nitrate was instantaneously added to the solution to obtain a silver iodide content of 40 mol% and a relatively uniform silver iodobromide content. The particles are obtained.

JP-A-56-16124 discloses that a silver iodobromide emulsion containing silver iodide having a halogen composition of 15 to 40 mol% and a pAg of a liquid containing a protective colloid is maintained in the range of 1 to 8. Discloses that a uniform silver iodobromide can be obtained.

After preparing seed crystals of silver iodobromide containing a high concentration of silver iodide, Japanese Patent Publication No. 48-3689 by Irie and Suzuki.
No. 0,424,424, or a method disclosed in US Pat.
Uniform silver iodobromide can also be obtained by the method of growing silver iodobromide grains by the method of increasing the addition concentration with time as disclosed in the specification of No. 45. These methods give particularly favorable results. The method of Irie et al. Is a method for producing hardly soluble inorganic crystals for photography by a metathesis reaction in which two or more kinds of inorganic salt aqueous solutions are simultaneously added in the presence of protective colloids in substantially equal amounts, and the inorganic salt aqueous solution to be reacted is kept constant. Adding at an addition rate Q higher than the addition rate and lower than the addition rate proportional to the total surface area of the growing hardly soluble inorganic salt crystals, that is, Q = γ or more and Q = αt ² + βt +
It is added at γ or less. On the other hand, Saito's method is a method for producing a silver halide crystal in which two or more kinds of inorganic salt aqueous solutions are simultaneously added in the presence of protective colloid, and the concentration of the inorganic salt aqueous solution to be reacted causes almost no new crystal nuclei to be generated. It is increased to the extent that it is not done.

In the formation of core grains, it is preferable to add silver halide fine grains to form silver halide grains instead of adding the silver salt aqueous solution and the halide aqueous solution to the reaction vessel holding the protective colloid aqueous solution. Regarding this method, the technique is disclosed in JP-A-1-183645 and US Pat. No. 4,879,208.

In the preparation of the silver halide grains of the present invention, the continuous layer may be formed as it is after the core grain is formed, but it is preferable to wash the core emulsion for desalting and then form the continuous layer. The continuous layer formation can also be prepared by various methods known in the field of silver halide photographic light-sensitive materials, but the simultaneous mixing method is preferable. A layer consisting essentially of silver iodobromide is formed such that the halogen composition of the continuous layer continuously changes from the core portion to the surface toward a low iodine content.

The addition rate of the soluble silver salt aqueous solution to the extent that new crystal nuclei are not generated in the crystal is a function of time Q
_{Assuming Ag} (t) (mol / min), it is most preferable that the function Q _I (T) (mol / min) of the addition rate of the soluble iodide aqueous solution with respect to time is decelerated by the following equation. The flow rate may be decelerated by using a quadratic function, a linear function, a quadratic function, or a combination of these functions, as long as the function is not largely deviated.

[0042]

[Equation 1]

Here, C is determined to be an iodine amount corresponding to the surface iodine content of the core, and A is most preferably a value such that the gradient of the flow rate deceleration does not cause a sudden misfit in the lattice constant.

Further, a soluble bromide aqueous solution is added as a third solution. As a method of addition, a triple jet method in which the soluble iodide aqueous solution is added from an addition port different from that of the soluble iodide aqueous solution may be used, but the soluble iodide aqueous solution and the soluble bromide aqueous solution are mixed well in advance with a mixer before the addition. It is preferable to use the double jet method. The soluble bromide aqueous solution is most preferably kept constant in pAg in the liquid phase in which silver halide is produced, but other functions may be used.

In forming the continuous layer, instead of adding the silver salt aqueous solution and the halide aqueous solution to the reaction vessel holding the protective colloid aqueous solution, silver halide fine particles may be added to form the continuous layer. This technique is disclosed in US Pat. No. 4,879,208. In this method, fine particles are formed in a mixing vessel provided near a reaction vessel for producing particles, and in order to change the halogen composition of the fine particles with respect to time in the same manner as the above-mentioned normal continuous layer formation, It is preferable that the flow rates of the halide aqueous solution, that is, the aqueous bromide solution and the iodide aqueous solution supplied to the mixing container are changed in the same manner as described above with respect to time, and the two liquids are mixed in advance and then supplied to the mixing container.

The slope of the decrease in the iodine content of the continuous layer from the inside to the surface is preferably such that a sudden misfit does not occur in the lattice constant. Therefore, the required thickness depends on the particle size and the iodine content of the core portion, but is 0.1 μm or more for large size particles of 1.0 μm or more and 0.05 μm or more for small size particles of less than 1.0 μm. It is desirable to be covered with. The silver amount ratio between the core portion and the continuous layer is preferably in the range of 0.1 to 7, and more preferably 0.1 to 5. The particle size after forming the continuous layer is preferably 0.1 to 3 μm. The size distribution after formation of the continuous layer may be narrow or wide, but one preferable grain is a monodisperse emulsion having a narrow size distribution (variation coefficient of 20% or less).

Next, guest silver salt epitaxy is bonded to the host crystal.

The formation of the junction crystal is carried out by adding the soluble silver salt aqueous solution having the same halogen composition as the guest crystal and the soluble silver salt aqueous solution after the formation of the host silver halide crystal. At this time as well, it is more preferable to keep the silver ion concentration constant, but in the case of silver chlorobromide, it may be possible to form homogeneous bonding particles without keeping it constant, and especially when the silver chloride content is If it is higher, add an aqueous solution of halogen salt to the suspension of host silver halide crystals,
Bonding particles can also be formed by adding an aqueous silver salt solution thereafter. Further, it is also possible to form a bonding grain by preparing a fine grain crystal having the same composition as the guest crystal separately from the host silver halide crystal, and mixing and physically ripening these two types of silver halide emulsions.

When the second halogen salt aqueous solution and the silver salt aqueous solution for forming a bonded crystal are added to the host crystal at the maximum addition rate within the range where nucleation is not newly formed, the formed bonded crystal has the added halogen. It has a composition close to that of the salt solution, and the composition of the host silver halide crystal is almost maintained at the initial composition. However, if deviated from the above conditions or if physical ripening is caused after maintaining the above growth conditions, the aqueous solution of halogen salt or the formed guest crystals and host silver halide crystals are regenerated to deposit the added guest crystals. The halogen composition of the crystal that causes crystallization and is formed in a junction is different from the initially expected halogen composition of the guest crystal. Therefore, the composition of the host silver halide crystal itself may be different from that of the original host crystal. In this case, it goes without saying that the constituent molar ratios of the host silver halide crystal and the bonded silver halide crystal may also change.

The change in the halogen composition of the host crystal and the junction crystal due to such recrystallization, or the change of the constituent molar ratio of the host crystal and the junction crystal occurs as much as the guest crystal is made to have a high silver chloride halogen composition. Cheap. Even with particles that have undergone these changes, the effects of the present invention can be realized as long as they initially have the shape of the bonded particles.

The ratio of this guest crystal to the host crystal is preferably 30 mol% or less, more preferably 15 mol% or less. Further, it is preferable to keep the silver potential (relative to SCE) at the time of depositing the guest crystal at 200 mV or less. More preferably, it is in the range of 60 mV to 150 mV. However, within this range, it is not always necessary to maintain the silver ion concentration constant.

Conventionally, in order to selectively bond silver chloride to the apexes and / or edges of a silver iodobromide host crystal having a {111} plane, as disclosed in European Patent Application No. 0019917. In addition, the host crystal required at least 15 mol% iodide. Also, as mentioned above,
A site indicator was required to bond silver salt epitaxy to selected sites of the host grain with respect to a silver iodobromide host crystal having a mol% or less of {111} plane.

However, the present inventor has found that the silver iodide crystal having a surface iodide content of 8 mol% or less and having a {111} face is used as a silver halide crystal having a multiple structure or a double structure without using a specific site indicator. By using particles,
It has been found that when a guest crystal substantially composed of silver chloride having a silver chloride content of 50 mol% or more is grown at a silver potential of 200 mV (vs. SCE) or less, the guest crystal is selectively bonded to the top and / or edge of the host crystal. ..

Generally, it is mainly {11
If a guest crystal consisting essentially of silver chloride is introduced into a silver iodobromide host crystal having a uniform structure of 1} planes, the guest crystals will be deposited non-selectively at random, but the above combination must be satisfied. It is totally unexpected that the guest crystal can be selectively introduced into the top and / or the edge at the point.

In the emulsion containing the junction type grain of the present invention, the ratio of the grain to the total grain is 50% or more in the projected area, and more preferably 80% or more.

The photographic material coated with the emulsion of the present invention has the advantages of being less susceptible to development inhibition, having high contrast, high sensitivity, and remarkably less intrinsic desensitization, and has the advantage that the combination of sensitizing dyes can be freely selected.

In order to control the grain growth during the formation of the host silver halide grains according to the present invention, as the silver halide solvent, for example, ammonia, rhodancali, rhodanammon, thioether compound (eg US Pat.
71157, 3574628, and 3704130.
Nos. 4,297,439 and 4,276,374), thione compounds (eg, JP-A-53-14431).
No. 9, No. 53-82408, No. 55-77737, and amine compounds (eg, JP-A No. 54-1007).
17).

In the present invention, during the process of silver halide grain formation or physical ripening and / or halogen conversion, cadmium salt, zinc salt, lead salt, thallium salt, iridium salt or its complex salt, rhodium salt or its complex salt, iron salt or You may make iron complex salt etc. coexist.

The emulsion of the present invention is usually spectrally sensitized. As the spectral sensitizing dye used in the present invention, a methine dye is usually used, which includes a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a hemicyanine dye, a styryl dye and a hemioxonol. A dye is included. Any of the nuclei normally used for cyanine dyes as a basic heterocyclic nucleus can be applied to these dyes. That is, a pyrroline nucleus, an oxazoline nucleus, a thiazoline nucleus, a pyrrole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus,
Imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc .; nucleus in which alicyclic hydrocarbon ring is fused to these nuclei; and nucleus in which aromatic hydrocarbon ring is fused to these nuclei, that is, indolenine nucleus, benzindolenine nucleus , Indole nucleus, benzoxazole nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, benzoselenazole nucleus,
Benzimidazole nucleus, quinoline nucleus, etc. can be applied.
These nuclei may be substituted on carbon atoms. The merocyanine dye or the complex merocyanine dye has a pyrazolin-5-one nucleus as a nucleus having a ketomethylene structure,
Thiohydantoin nucleus, 2-thiooxazolidine-2,4
-5- to 6-membered heterocyclic nuclei such as a dione nucleus, a thiazolidine-2,4-dione nucleus, a rhodanine nucleus and a thiobarbituric acid nucleus can be applied. The sensitizing dye is added after chemical ripening or before chemical ripening. The sensitizing dye is most preferably added to the silver halide grains of the present invention during the chemical ripening or before the chemical ripening (after that, during grain formation or physical ripening).

The silver halide emulsion is usually chemically sensitized. That is, a sulfur sensitization method using a compound containing sulfur capable of reacting with active gelatin or silver (for example, thiosulfate, thioureas, mercapto compounds, rhodanins); a reducing substance (for example, first tin salt, Amines, hydrazine derivatives, formamidinesulfinic acid, silane compounds)
The reduction sensitization method using a noble metal sensitization method using a noble metal compound (for example, a metal complex salt of Group VIII of the periodic table such as Pt, Ir, and Pd in addition to a gold complex salt) can be used alone or in combination. The photographic emulsion used in the present invention may contain various compounds for the purpose of preventing fog during the production process of the light-sensitive material, during storage or during photographic processing, or stabilizing photographic performance. That is, azoles such as benzothiazolium salts, nitroindazoles, triazoles, benzotriazoles, benzimidazoles (particularly nitro- or halogen-substituted compounds), heterocyclic mercapto compounds such as mercaptothiazoles, mercaptobenzothiazoles,
Mercaptobenzimidazoles, mercaptothiadiazoles, mercaptotetrazoles (particularly 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines; the above-mentioned heterocyclic mercapto compounds having a water-soluble group such as a carboxyl group or a sulfone group; thioketo Antifoggants such as compounds, eg oxazoline thiones; azaindenes, eg tetraazaindenes (especially 4-hydroxy substituted (1,3,3a, 7) tetraazaindenes); benzenethiosulfonic acids; benzenesulfinic acid; Many compounds known as agents or stabilizers can be added. The timing of addition of these antifoggants or stabilizers is usually carried out after chemical sensitization, but more preferably it can be selected during chemical ripening or before the start of chemical ripening.

The emulsion of the present invention can be used in a photographic material having an arbitrary layer structure regardless of whether the emulsion layer is one layer or two or more layers. A silver halide multilayer color photographic material using the emulsion of the present invention has a multilayer structure in which emulsion layers containing a binder and silver halide grains for separately recording blue, green and red light are superposed. Each emulsion layer consists of at least two layers, a high speed layer and a low speed layer. The silver halide emulsion of the present invention can be applied to color photographic materials, but photographic materials other than those having one or more emulsion layers, such as X-ray photographic materials, black and white photographic materials, and plate-making. It can be similarly applied to photographic materials, photographic papers and the like. Various additives of the silver halide emulsion of the present invention, such as binder, chemical sensitizer, spectral sensitizer, stabilizer, gelatin hardener, surfactant, antistatic agent, polymer latex, matting agent, color coupler, There is no particular limitation on the support, coating method, exposure method, development processing method, etc. of photographic materials using ultraviolet absorbers, anti-fading agents, dyes and emulsions thereof, for example, Research Disclosure Volume 176, Item 17643 (RD -17643),
Volume 187, Item 18716 (RD-18716)
225 and Item 22534 (RD-2253).
The description in 4) can be referred to.

The description of these Research Disclosures is shown below. ──────────────────────────────────── Additive type RD17643 RD18716 RD22534 ───────── ──────────────────────────── 1 Chemical sensitizer page 23 648 right column page 24 2 Sensitivity enhancer page 648 right column 3 Spectral sensitizer, pages 23 to 24, page 648, right column to pages 24 to 28, supersensitizer, page 649, right column 4, whitening agent, page 24, 5 antifoggant, pages 24 to 25, page 649, right column to pages 24, 31 Page and stabilizer 6 light absorber, page 25-26 page 649 right column-filter dye page 650 left column ultraviolet absorber 7 stain inhibitor 25 page right column 650 page left-right column 8 dye image stabilizer page 25 page 32 9 Hardening agent Page 26 Page 651 Left column Page 28 10 Binder 26 Page 651 Left column 11 Plastic , Lubricants page 27, page 650, right column, 12 coating aids, pages 26 to 27, page 650, right column, surfactants, 13 static inhibitors, page 27, page 650, right column, 14 color couplers, page 25, page 649, page 31 ─────── ──────────────────────────────

The color coupler used in the present invention preferably has a ballast group or is polymerized to be diffusion resistant. A two-equivalent coupler having a coupling-active group substituted with a coupling-off group is preferable to a four-equivalent coupler having a hydrogen atom at the coupling active point, because the amount of coated silver can be reduced. Further, a coupler in which the color-forming dye has an appropriate diffusibility, a non-color-forming coupler, or a DIR coupler which releases a development inhibitor with a coupling reaction or a coupler which releases a development accelerator can also be used.

A typical example of the yellow coupler which can be used in the present invention is an oil protect type acylacetamide type coupler. A typical example thereof is an oxygen atom releasing yellow coupler or a nitrogen atom releasing yellow coupler. The α-pivaloylacetanilide type coupler is excellent in the fastness of the color forming dye, especially the light fastness, while the α-benzoylacetanilide type coupler can obtain a high color density. The magenta coupler that can be used in the present invention is an oil-protection type,
Examples thereof include indazolone-based or cyanoacetyl-based, preferably 5-pyrazolone-based and pyrazoloazole-based couplers such as pyrazolotriazoles. The 5-pyrazolone-based coupler is preferably a coupler in which the 3-position is substituted with an arylamino group or an amylamino group, from the viewpoint of the hue and color density of the color forming dye. U.S. Pat. No. 4,500,6 in terms of low yellow sub-absorption of color forming dye and light fastness.
The imidazo [1,2-b] pyrazoles described in US Pat. No. 30, are preferred, and the pyrazolo [1,5-b] [1,2,4] triazoles described in US Pat. No. 4,540,650 are particularly preferred. Cyan couplers that can be used in the present invention include oil-protection type naphthol type and phenol type couplers. US Patent 24742
Naphthol-based couplers described in Japanese Patent No. 93, preferably US Pat. Nos. 4,052,212 and 4,146,396.
No. 4,228,233 and No. 4,296,200, the oxygen atom-elimination type two-equivalent naphthol couplers are described as typical examples. JP-A-60-
237448, 61-153640 and 61
-145557 of naphthol described in each publication
A cyan coupler having a sulfonamide group or an amide group substituted at the position is also excellent in the fastness of a color image and can be preferably used in the present invention. The graininess can be improved by using a coupler in which the color forming dye has an appropriate diffusibility.
Examples of such couplers include magenta couplers in U.S. Pat. No. 4,366,237 and British Patent 2,125,570, and yellow in European Patent No. 96570 and West German Patent Application No. 3234533. Specific examples of magenta and cyan couplers are described.

The present invention may contain a coupler which releases a development inhibitor upon development, a so-called DIR coupler. Among the DIR couplers, more preferable in combination with the present invention is a developer inactivating type represented by the coupler described in JP-A-57-151944; U.S. Pat.
248962 and JP-A-57-154234.
There is a timing type represented by the coupler described in JP-A-60-184248; and a reaction type represented by the coupler described in JP-A-60-184248. Particularly preferred is JP-A-5
7-151944, 58-217932, 60
No. 218644, No. 60-225156, and No. 60-233650, and a developer deactivating DIR coupler and a reactive DIR coupler described in JP-A-60-184248. it can. In the photographic material of the present invention, a compound which releases a nucleating agent or a development accelerator or a precursor thereof (hereinafter referred to as "development accelerator") in an image during development can be used. A typical example of such a compound is British Patent No. 2
No. 097140 and No. 2131188, each of which is a coupler which releases a development accelerator or the like by a coupling reaction with an oxidized product of an aromatic primary amine developing agent, that is, a DAR coupler.

Specific examples of the high boiling point organic solvent used for dispersing the color coupler include phthalic acid esters (dibutyl phthalate, dicyclohexyl phthalate, di-
2-ethylhexyl phthalate, decyl phthalate, etc.), phosphoric acid or phosphonic acid esters (triphenyl phosphate, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate, tricyclohexyl phosphate, tri-2-ethylhexyl phosphate, tridodecyl phosphate, tol) Butoxyethyl phosphate, trichloropropyl phosphate, di-
2-ethylhexylphenylphosphonate, etc., benzoic acid esters (2-ethylhexylbenzoate, dodecylbenzoate, 2-ethylhexyl-p-hydroxybenzoate etc.), amides (diethyldodecane amide, N-tetradecylpyrrolidone etc.), alcohols or Phenols (isostearyl alcohol,
2,4-di-tert-amylphenol, etc., aliphatic carboxylic acid esters (dioctyl azelate, glycerol tributyrate, isostearyl lactate,
Trioctyl citrate, etc., aniline derivatives (N,
N-dibutyl-2-butoxy-5-tert-octylaniline and the like), hydrocarbons (paraffin, dodecylbenzene, diisopropylnaphthalene and the like) and the like. As the auxiliary solvent, an organic solvent having a boiling point of about 30 ° C. or higher, preferably 50 ° C. or higher and about 160 ° C. or lower can be used. Typical examples are ethyl acetate, butyl acetate, ethyl propionate, methyl ethyl ketone, cyclohexanone, 2- Examples include ethoxyethyl acetate and dimethylformamide.

Examples of the gelatin hardening agent include active halogen compounds (2,4-dichloro-6-hydroxy-1,
3,5-triazine and its sodium salt) and active vinyl compounds (1,3-bisvinylsulfonyl-2)
-Propanol, 1,2-bis (vinylsulfonylacetamide) ethane or a vinyl polymer having a vinylsulfonyl group in its side chain) is preferable because it rapidly cures hydrophilic colloid such as gelatin and gives stable photographic characteristics. N-carbamoylpyridinium salts (1-morpholinocarbonyl-3-pyridinio) methanesulfonate, etc. and haloamidinium salts (1- (1-chloro-
(Pyridinomethylene) pyrrolidinium-2-naphthalene sulfonate) also has a fast curing rate and is excellent.

The color photographic material using the silver halide photographic emulsion of the present invention is usually subjected to washing treatment or stabilizing treatment after development, bleach-fixing or fixing treatment. In the water washing step, it is general to carry out countercurrent water washing of two or more tanks to save water. As a stabilization treatment, instead of the water washing step, JP-A-57 / 1982
A typical example is a multi-stage countercurrent stabilization treatment as described in Japanese Patent No. 8543.

The color developing solution used for the development processing of the photographic material of the present invention is preferably an alkaline aqueous solution containing an aromatic primary amine type color developing agent as a main component. Although aminophenol compounds are also useful as the color developing agent, p-phenylenediamine compounds are preferably used, and a typical example thereof is 3-methyl-4-amino-.
N, N-diethylaniline, 3-methyl-4-amino-
N-ethyl-N-β-hydroxyethylaniline, 3-
Methyl-4-amino-N-ethyl-N-β-methanesulfonamidoethylaniline, 3-methyl-4-amino-
Mention may be made of N-ethyl-N-β-methoxyethylaniline and their sulphates, hydrochlorides or p-toluenesulphonates. Two or more of these compounds can be used in combination depending on the purpose.

When reversal processing is carried out, black and white development is usually carried out before color development. In this black and white developer,
Known black-and-white developing agents such as dihydroxybenzenes such as hydroquinone, 3-pyrazolidones such as 1-phenyl-3-pyrazolidone or aminophenols such as N-methyl-p-aminophenol can be used alone or in combination. The color developing solution and the black and white developing solution generally have a pH of 9 to 12. The replenishing amount of these developers depends on the color photographic material to be processed, but is generally 3 liters or less per 1 square meter of the photographic material, and should be 500 ml or less by reducing the bromide ion concentration in the replenishing solution. You can also The photographic emulsion layer after color development is usually bleached. The bleaching process may be performed at the same time as the fixing process (bleach-fixing process) or separately. Further, in order to speed up the processing, a processing method of bleach-fixing processing after bleaching processing may be used. Further, the aminopolycarboxylic acid iron (III) complex salt is particularly useful in both the bleaching solution and the bleach-fixing solution.
The pH of a bleaching solution or a bleach-fixing solution using these aminopolycarboxylic acid iron (III) complex salts is usually 5.5 to 8,
It is also possible to process at a lower pH for speeding up the process. The bleaching solution, bleach-fixing solution and their pre-bath are
A bleaching accelerator can be used if necessary. As a useful bleaching accelerator, a compound having a mercapto group or a disulfide group is preferable from the viewpoint of a large accelerating effect, and particularly, US Pat. No. 3,893,858, West German Patent 1,290,812 and JP-A-53-95630
The compounds described in the publication are preferred. Further US Patent No. 4
The compounds described in the specification of 552834 are also preferable. These bleaching accelerators may be added to the light-sensitive material.

The silver halide color photographic material of the present invention comprises
After the desilvering process, it is common to carry out washing and / or stabilizing steps. The amount of rinsing water in the rinsing process depends on the characteristics of the photographic material (for example, depending on the materials used such as couplers), the application, and the temperature of the rinsing water, the number of rinsing tanks (number of stages), replenishment method such as countercurrent, forward flow, etc. It can be set in a wide range. Of these, the relationship between the number of washing tanks and the amount of water in the multi-stage countercurrent system is described in the Journal of the Society of Motion Picture and T
elevision Engineers Volume 64, pp. 248-253 (1
May 955 issue).

[0072]

EXAMPLES The present invention will be further described below with reference to examples. [Example 1] Emulsion Em-1 <Silver iodobromide fine grain emulsion> 42 liters of a 1.9% by weight gelatin solution having pBr = 3.4 was mixed with 42 liters by a double jet method while stirring it.
Two liters each of a 3 M / liter aqueous silver nitrate solution and a halogen salt aqueous solution containing 0.89 M / liter potassium bromide and 0.27 M / liter potassium iodide were added over 20 minutes. During this time, the gelatin solution was kept at 35 ° C. After that, the emulsion was washed by a conventional flocculation method, dissolved, and then adjusted to pH 6.4 and pAg 8.4.
The obtained silver iodobromide fine particles (silver iodide content: 24 mol%) had an average grain size of 0.06 μm.

Emulsion Em-2 <Silver iodobromide core grain emulsion> 1.2 liters of 1% potassium bromide was added to 24 liters of water, and 5% 3.6 dithia-1,8- was added thereto while stirring.
2.4 liters of a methanol solution of octanediol was added, and a fine grain emulsion Em-1 (silver iodide content: 24 mol%) was added to a reaction vessel kept at 76 ° C. in an amount of 0.35 mol per silver.
Added over 0 minutes. Thus, nucleation was performed by obtaining silver iodobromide grains having a projected area circle equivalent diameter of 0.23 μm and a silver iodide content of 24 mol%. Then similarly at 76 ℃
In (1), the fine grain emulsion Em-1 was added in an amount of 11.4 mol silver over 87 minutes. After that, the emulsion was cooled, washed with water, and then adjusted to pH 6.5 and pAg 7.6. The obtained silver iodobromide grains were monodisperse octahedral grains having an average equivalent circle diameter of 0.72 μm (variation coefficient: 8%). The iodine content was 24 mol%.

Emulsion Em-3 <Preparation of Base Grain by Forming Continuous Layer> For the silver iodobromide core grain emulsion having an iodine content of 24 mol% obtained in Emulsion Em-2, a prescribed value was applied from the core to the shell surface. Then, shell formation was performed by continuously changing from 24 mol% to 0 mol%. The silver iodobromide core grain emulsion obtained in Emulsion Em-2 was dissolved in 700 cc of a solution containing 3% by weight of gelatin in an amount of 0.18 mol silver, and the temperature was adjusted to 76
It was kept at ℃. Thereafter, an aqueous solution containing silver nitrate in an amount of 0.69 mol in 187 minutes, an aqueous potassium iodide solution in an amount of 0.055 mol, and an aqueous potassium bromide solution in 0.84 mol / liter were added. At this time, the silver nitrate aqueous solution was 3.
A constant amount of 7 × 10 ⁻³ mol / min was added, and the potassium iodide aqueous solution had an initial speed of 8.8 × 10 ⁻⁴ mol / min to a final speed of 0 mol / min.
It was added by deceleration with a quadratic function with respect to time so that it became minutes. The aqueous potassium bromide solution was added while controlling so that the silver potential was kept at OmV (vs. saturated calomel electrode). Further, the potassium iodide aqueous solution and the potassium bromide aqueous solution were well mixed just before being added to the reaction vessel and then added. After this, the emulsion was cooled and washed with water, and then the pH was adjusted to 6.
5, adjusted to pAg 8.1. The obtained silver iodobromide grains were monodisperse octahedral grains (variation coefficient: 10%) having an average equivalent circle diameter of 1.22 μm. The average iodine content was 11.3 mol%. The surface content by XPS is 3 mol%
Met. An electron microscope replica photograph of comparative emulsion Em-3 is shown in FIG.

Emulsion Em-4 <Invention> Silver chloride epitaxy was selectively formed on the apexes and / or edges of the base grains of the base grain emulsion obtained in Emulsion Em-3. The base grain emulsion obtained in Emulsion Em-3 was dissolved in 1.2 liter of water in an amount of 0.38 mol silver, and the temperature was kept at 50 ° C. After this, 0.05 in 11 minutes
An aqueous solution containing a molar amount of silver nitrate was added, and at the same time, a 0.40 mol / liter sodium chloride aqueous solution was added by a control and double jet method so that the silver potential was kept at +100 mV (vs. saturated calomel electrode). Was done.

Thereafter, the emulsion was cooled to 35 ° C., washed by a conventional flocculation method, 30 g of bone gelatin was added, adjusted to pH 6.5 and pAg 8.5 at 40 ° C., and stored in a cool dark place. did.

An electron microscope replica photograph of Emulsion Em-4 according to the present invention is shown in FIG.

As is clear from FIG. 1, a large number of silver chloride epitaxies are selectively formed at the apexes and / or edges of the octahedral base.

Emulsion Em-5 <Comparative Example> Emulsion Em-4 was prepared in the same manner as emulsion Em-4 except that the silver potential for depositing silver chloride was +250 mV (vs. saturated calomel electrode). When the obtained grains were observed by an electron microscope replica photograph, a large number of silver chloride epitaxies were randomly generated on the octahedral base {111} face as shown in FIG.

Example 2 Emulsion Em-6 <Preparation of Double-Structure Host Grains> The iodine content was further added to the silver iodobromide core grain emulsion having an iodine content of 24 mol% obtained in Emulsion Em-2. After 24% by mole of silver iodobromide was coughed to grow core particles, a silver bromide shell was formed. The silver iodobromide core grain emulsion obtained in Emulsion Em-2 was dissolved in 700 cc of a solution containing 3% by weight of gelatin in an amount of 0.18 mol silver, and the temperature was 76 ° C.
Kept at.

Thereafter, in 63 minutes, an aqueous solution containing 0.23 mol of silver nitrate, an aqueous solution of 0.055 mol of potassium iodide, and an aqueous solution of 0.84 mol / liter of potassium bromide were prepared. The addition was controlled so that the silver potential was kept at 0 mV (vs. saturated calomel electrode).

After that, an aqueous solution containing 0.46 mol of silver nitrate in 190 minutes and a 0.84 mol / liter aqueous solution of potassium bromide were added so that the silver potential was kept at 0 mV (vs. saturated calomel electrode). It was added by the control double jet method.

Thereafter, the emulsion was cooled to 35 ° C., desalted by a conventional flocculation method, 50 g of bone gelatin was added, adjusted to pH 6.5 and pAg 8.5 at 40 ° C., and stored in a cool dark place. did.

The obtained particles have an average equivalent circle diameter of 1.22 μm.
Were monodisperse particles (variation coefficient: 12%).

The outer shape of the grains was an octahedron or a tetrahedron with very few {100} faces.

The average iodine content is 11.3 mol%.
Met.

Surface iodine content by XPS is 3 mol%
Met.

Emulsion Em-7 <Invention> For the double structure base grain emulsion obtained in Emulsion Em-6,
Silver chloride epitaxy was selectively formed on the tops and / or edges of the base grains. The base grain emulsion obtained in Emulsion Em-6 was dissolved in 1.2 liters of water in an amount of 0.38 mol silver, and the temperature was kept at 50 ° C. Then, add an aqueous solution containing silver nitrate in an amount of 0.05 mol in 11 minutes,
At the same time, an aqueous 0.40 mol / liter sodium chloride solution was added by the control and double jet method so that the silver potential was kept at +100 mV (vs. saturated calomel electrode).

Thereafter, the emulsion was cooled to 35 ° C., washed by a conventional flocculation method, 30 g of bone gelatin was added, adjusted to pH 6.5 and pAg 8.5 at 40 ° C., and stored in a cool dark place. did.

In the electron microscope replica image of the emulsion Em-7 according to the present invention, silver chloride epitaxy was selectively formed in large numbers on the tops and / or edges of the host grains as in FIG.

Emulsion Em-8 <Comparative Example> Emulsion Em-7 was prepared in the same manner as emulsion Em-7 except that the silver potential for depositing silver chloride was set to 250 mV (vs. saturated calomel electrode). When the obtained grains are observed by an electron microscope replica photograph, the silver chloride epitaxy has an octahedral base {1 as in Fig. 2.
11} planes were randomly generated in large numbers.

Emulsion Em-9 <Uniform silver iodobromide host grains> Silver iodobromide host grains having a uniform iodide content of 3 mol% were formed. KB in 1 liter of 3% aqueous gelatin solution
1 liter of AgNO ₃ 1.25 mol / liter 240 cc and simultaneously KBr 1.20 mol and KI 0.038 mol while keeping a well-stirred tank containing r5 g and ammonia / ammonium nitrate as a solvent at a temperature of 75 ° C. Aqueous solution was added.

At this time, a mixed solution of KBr / KI was added so that the silver potential (vs. SCE) was always kept at 30 mV.

Subsequently, AgNO ₃ 0.75 mol / l 580 cc and KBr 1.20 mol and KI 0.
A 1 liter aqueous solution containing 038 mol was added while maintaining the silver potential at 0 mV.

After desalting and washing with water, inert gelatin was added and redispersed.

This emulsion had a pH of 6.8 and a pAg of 7.6 of 1
1 mol of silver halide and 70 g of gelatin per Kg
Met.

This emulsion was an octahedron containing 3 mol% of silver iodide and having an edge length of 1.22 μm.

The surface silver iodide content by XPS was 3 mol%.

Emulsion Em-10 <Comparative Example> The base grain emulsion obtained in Emulsion Em-9 was 0.38 in terms of silver amount.
Dissolve the molar amount in 1.2 liters of water and
It was kept at ℃.

Thereafter, an aqueous solution containing silver nitrate in an amount of 0.05 mol in 11 minutes was added, and at the same time, the silver potential was +10.
0 .. so that it is kept at 0 mV (vs. saturated calomel electrode).
A 40 mol / liter chloride aqueous solution was added by the control double jet method.

After that, the emulsion was cooled to 35 ° C., washed by a conventional flocculation method, 30 g of bone gelatin was added, adjusted to pH 6.5 and pAg 8.5 at 40 ° C., and stored in a cool dark place. did.

When the obtained grains were observed by an electron microscope replica photograph, a large number of silver chloride epitaxies were randomly generated on the octahedron-based {111} plane as in FIG.

Example 3 Em-3 was dissolved at 45 ° C., appropriate hypo was added, and the mixture was aged for 1 hour to obtain optimum sensitivity.

The above emulsion was placed on cellulose triacetate in an amount of 3 silver.
It was applied at g / m ² . The sample name is (Em-3 + Sulfur Sensitization).

To the above emulsion, 0.22 mmol of Dye A was added per 1 mol of Ag, and the emulsion was coated. The sample name is (Em-3 + sulfur sensitization + dye A).

After 0.22 mmol of the dye A was added to 1 mol of silver of Em-3 dissolved at 45 ° C., an appropriate amount of hypo was added to give maximum sensitivity (Em- 3 + Sulfur sensitization). The sample name is (Em-3 + Dye A + Sulfur Sensitization).

[0107]

[Chemical 1]

Em-4 was dissolved at 45 ° C., an appropriate amount of hypo was added, and the mixture was aged for 1 hour to obtain the optimum sensitivity. The sample name is (Em-4 + Sulfur Sensitization).

Dye A was added to this emulsion in an amount of 0.22 mmol per mol of emulsion particles to obtain the above coated sample (Em
-4 + sulfur sensitization + dye A).

Similarly to (Em-3 + Dye A + Sulfur Sensitization), Em-4 was sulfur-sensitized with an appropriate amount of hypo after the addition of Dye A, and then coated. The sample name is (Em-4 + Dye A + Sulfur sensitization).

These samples were subjected to a blue filter (BPN42 manufactured by Fuji Photo Film) and a blue cut filter (SC52 manufactured by Fuji Photo Film) using a tungsten lamp.
Was used for 1/10 second imagewise exposure.

After that, a developing solution (MAA-1 below) was used for development at 20 ° C. for 5 minutes.

Table 1 shows the reciprocal of the exposure amount that gives fog + density of 0.1.

[0114]

[Table 1] Table 1 ──────────────────────────────────── Blue filter Blue cut filter ── ────────────────────────────────── Ratio (Em-3 + Sulfur Sensitization) 100 ── (Em-3 + Sulfur sensitization + dye A) 17 85 comparison (Em-3 + dye A + sulfur sensitization) 18 90 ───────────────────────────── ───────── (Em-4 + Sulfur sensitized) 503 ── Emitted (Em-4 + Sulfur sensitized + Dye A) 361 1810 Ming (Em-4 + Dye A + Sulfur sensitized) 477 2394 ── ──────────────────────────────────

As can be seen from Table 1, the light-sensitive material using the emulsion of the present invention achieves higher sensitivity than the light-sensitive material using host grains, and the intrinsic desensitization by the sensitizing dye is remarkably improved. .

MAA-1 developer ──────────────────────────────────── N′-methyl-p - aminophenol sulfate 2.5 g L-ascorbic acid 10g Na box (NaBO ₂₎ was added to 35g of potassium bromide 1g water total amount 1 liter ─────────────────── ─────────────────

Example 4 Prepared in Example 3 (Em-
(3 + sulfur sensitized) emulsion was prepared under exactly the same conditions, and gold sensitization was performed by using chloroauric acid together.

This emulsion was used as a color photographic material (JP-A-62-62
It was used for the first red-sensitive emulsion layer (the same as Sample-1 of Example 1 of JP-A-203161) (the same as the third layer of Sample-1 of the same publication except that the above emulsion was used). When this color photographic material was processed by a usual method (the same as the processing methods (A) and (B) described in the same publication), all showed good photographic properties.

[Brief description of drawings]

FIG. 1 is a representative replica electron micrograph showing a shape of a crystal in which silver chloride epitaxy is formed on edges and / or apexes of a base grain forming a continuous layer.

FIG. 2 is a representative replica electron micrograph showing the shape of a crystal in which silver chloride epitaxy is formed on the surface of a base grain forming a continuous layer.

FIG. 3 is an electron microscope replica photograph of comparative emulsion Em-3.

Claims (3)

[Claims] 1. A photographic material having a silver halide emulsion layer on a support, which has a {111} surface mainly and has a surface silver iodide content of 8 mol% or less as a halogen composition structure. Alternatively, the silver halide grains in which silver salt epitaxy is selectively bonded to the tops and / or edges of the host grains having a multiple structure are 50% of the silver halide grains contained in the emulsion layer.
% Of silver halide photographic material. 2. A silver potential of a saturated calomel electrode with respect to a double or multi-structured grain having a {111} surface and having a surface silver iodide content of 8 mol% or less as a halogen composition structure has a silver potential of 200 mV. Silver salt epitaxy consisting mainly of silver chloride at less than the top of the host grain and / or
Alternatively, a method for producing a silver halide photographic material, which comprises selectively bonding to a ridge and coating the silver halide emulsion thus obtained on a support. 3. A core portion which has a high iodine content inside and is substantially silver iodobromide, and a low iodine content which changes continuously from the inside of the grain toward the surface. It is composed of a shell portion containing a continuous layer of silver iodobromide, mainly {1
11} surface and the silver iodide content of the surface is 8 mol% or less, the silver potential of the saturated calomel electrode is 2
A silver salt epitaxy mainly consisting of silver chloride of less than 00 mV is selectively bonded to the tops and / or edges of host grains, and the silver halide emulsion thus obtained is coated on a support. Manufacturing method of silver halide photographic material.