JPH07191426A - Silver halide photographic emulsion and silver halide photograophic sensitive material - Google Patents

Abstract

PURPOSE:To provide a silver halide photographic emulsion which gives a silver halide photographic photosensitive material having excellent sensitivity, graininess, and especially sensitivity and graininess after exposure and storage for a long period and to obtain a silver halide photographic photosensitive material using this emulsion. CONSTITUTION:This silver halide photographic emulsion contains silver halide particles and a dispersion medium. The silver halide particles included in the silver halide emulsion has the average silver iodide content between >=2mol% and <30mol%. The average silver iodide content I1 (mol%) in the outermost layer of the silver halide particle and the average silver iodide content I2 (mold) of the silver halide particle are in the relation of I1<I2. Further, inner part of the particle is sensitized by reduction. The silver halide photographic sensitive material contains this emulsion.

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 emulsion and a silver halide photographic light-sensitive material using the same, and more specifically, it has excellent sensitivity, graininess, and sensitivity after exposure and long-term storage. The present invention relates to a silver halide photographic emulsion used in a silver halide photographic light-sensitive material and a silver halide photographic light-sensitive material using the same.

[0002]

2. Description of the Related Art The spread of photography equipment such as cameras has been increasing in recent years, and the opportunity for photography using silver halide photographic light-sensitive materials has been increasing.

The demands for higher sensitivity and higher image quality are becoming stronger and stronger. One of the dominant factors for high sensitivity and high image quality of silver halide photographic materials is silver halide grains. Development of silver halide grains aiming at higher sensitivity and higher image quality Has traditionally been pursued in the industry.

However, as is generally done, when the grain size of silver halide grains is reduced in order to improve the image quality, the sensitivity tends to decrease, so that both high sensitivity and high image quality can be achieved at the same time. There was a limit.

A technique for improving the sensitivity / size ratio per silver halide grain is being researched in order to further improve the sensitivity and the image quality. One of them is a tabular silver halide grain. The technology of using is Japanese Patent Laid-Open No. 58-111935
Issue 58-111936, Issue 58-111938, Issue 58-113927,
No. 59-99433, etc.

When these tabular silver halide grains are compared with so-called regular crystal silver halide grains such as octahedron, decahedron or hexahedron, the surface area becomes large when the volume of silver halide grains is the same, and Since many sensitizing dyes can be adsorbed on the surface of the silver halide grain, there is an advantage that the sensitivity can be further enhanced.

Further, Japanese Patent Application Laid-Open No. 63-92942 discloses a technique of providing another boundary core having a silver iodide content inside a tabular silver halide grain, and Japanese Patent Application Laid-Open No. 63-163451 discloses the longest distance between twin planes. Techniques using tabular silver halide grains having a grain thickness ratio to the grain ratio of 5 or more have been adopted, and effects on sensitivity and graininess have been shown respectively.

Further, JP-A-63-106746 discloses a tabular silver halide grain having a substantially layered structure in a direction parallel to two principal planes facing each other. Have a layered structure separated by planes substantially parallel to two opposing main planes, and the average silver iodide content of the outermost layer is the average silver iodide content of the entire silver halide grain. The techniques using tabular silver halide grains each having at least 1 mol% higher than the above are described.

In addition to this, Japanese Patent Application Laid-Open No. 1-183644 discloses a technique using tabular silver halide grains characterized in that the silver iodide containing silver iodide has a completely uniform silver iodide distribution. There is.

In addition, a technique for controlling carriers by metal doping is also known. Metal doping is a technique for improving photographic characteristics by mainly containing a polyvalent metal compound in silver halide grains.

Techniques for doping Ir compounds in JP-A-62-7042 and JP-A-1-105940 are disclosed in JP-A-1-121844.
Techniques for doping Fe compounds are disclosed respectively.

In JP-A-3-196135 and JP-A-3-89641, a silver halide photographic emulsion produced in the presence of an oxidizing agent for silver and a silver halide photographic light-sensitive material using the same were used. The sensitivity and the effect on fog are disclosed.

Further, for example, in Japanese Patent Laid-Open No. 63-220238, a technique using a silver halide emulsion containing tabular silver halide grains in which the positions of dislocation lines are defined is disclosed in Japanese Patent Laid-Open No. 3-175440. The technology of using a silver halide emulsion containing tabular silver halide grains in which dislocations are concentrated in is disclosed, and in Japanese Examined Patent Publication No. 3-18695, a technology of using a silver halide grain having a clear core / shell structure. But,
In Japanese Examined Patent Publication No. 3-31245, a technique relating to a silver halide grain having a core / shell three-layer structure has been taken up, and each has been studied as a technique for increasing sensitivity.

However, these conventional techniques have a limit in achieving both high sensitivity and high image quality, and are not sufficient to meet the recent demands for the light-sensitive material. Therefore, it is desired to develop a better technique. It was rare.

On the other hand, regarding reduction sensitization, the journal
Of Photographic Science (Journal of Pho
tographic Science 25, 19-27 (1977) and Photographic Science and Engineering, 23, 113.
As described on page 117 (1979), reduction-sensitized nuclei that have been appropriately applied are not limited to the Photographie Correspondents (P
hotographishe Korrespondenz) Volume 1, 20- (1957) and Photographic Science and Engineering 19th
As described by Michel and Lowe in the report of Vol. 49-55 (1975), it has been thought that it contributes to sensitization through the reaction represented by the following formula during exposure.

AgX + hv → e- + h + (1) Ag2 + h + → Ag + + Ag (2) Ag → Ag + + e- (3) where h + and e- are free holes and free electrons generated by exposure. ,
hv is a photon and Ag2 is a reduction sensitized nucleus.

However, photographic science
And Engineering (Photographic Science and
Engineering) Volume 16, pp. 35-42 (1971) and Volume 23, 1
According to pages 13 to 117 (1979), reduction sensitized nuclei have the property of trapping not only holes but also electrons.
The present situation is that the above theory alone does not always provide a sufficient explanation.

Further, unlike the above-described light-sensitive area peculiar to silver halide grains, in the color sensitized region in the spectrally sensitized silver halide grains actually used in the silver halide photographic light-sensitive material. The function of reduction sensitization was extremely difficult to predict because of the complexity of the photosensitization process.

Generally, in a spectrally sensitized silver halide emulsion, a dye absorbs light unlike the intrinsic light-sensitive region, and the initial process of light exposure is represented by formula (4) instead of formula (1). It has been thought to have been done.

Dye + hv → Dye + + e- (4) Whether the dye holes (Dye +) and electrons (e-) shown on the right side are transferred to the silver halide grain depends largely on the nature of the dye. When focusing on holes, it has been generally considered that the sensitization efficiency is better when the dye holes are not transferred inside the grain.

This is true of, for example, Photographic Science and Engineering (Photographic
Science and Engineering) 24, 138-143 (1980)
In the context of the dye's oxidation potential (Eox).

However, the International Congress
Of Photographic Science (International
Congress of Photographic Science) Abstracts, 159-162
Page (1978) and Photographic Science and
Engineering (Photographic Science and Enginee
ring) Vol. 17, pp. 235-244 (1973), sensitizing dyes such that dye holes (Dye +) generated during exposure remain on the surface of silver halide grains bleach fog nuclei and reduction sensitizing nuclei on the surface. It is expected that the latent image on the surface will be bleached and rather desensitized in the most common surface latent image type emulsion.

As described above, whether the reduction sensitization should be performed on the surface or inside of the silver halide grain in the spectrally sensitized system, and what kind of dye is effective when combined It is not yet known if it will be done.

As a method of actually using such reduction sensitization in a silver halide emulsion, a method of applying it to the surface of silver halide grains, a method of applying it during the growth of silver halide grains, or a case where a seed crystal is used for grain growth is used. There are several known methods for subjecting the seed crystal to reduction sensitization in advance.

When the method of applying to the grain surface is used in combination with another sensitizing method (for example, a gold compound or a sulfur compound), undesired fogging increases remarkably, which is not suitable for practical use.
On the other hand, there is also a report that the method of performing reduction sensitization during silver halide growth does not have the above-mentioned drawbacks even when used in combination with other sensitization methods. For example, such a method is disclosed in JP-A-48-878.
No. 25, JP-A-57-179835. But,
These publications report an improvement in the intrinsic sensitivity of silver halide, but do not mention a system that is spectrally sensitized. JP-A-58-127920 describes that spectral sensitization improves the spectral sensitivity of a system that undergoes reduction sensitization inside the grain. It is said that the effect is limited to a dye having an oxidation potential Eox of more than 0.5 V, and there are practical restrictions.

Nowadays, in the market where the stability of quality is becoming more and more important, the stabilization of the latent image is getting more attention than ever before. A survey of consumers' usage of silver halide photographic light-sensitive materials showed that the photographs were not immediately put into development and were left in the camera for a while without being processed. It is becoming clear that the film cannot be ignored for use in extremely severe situations such as when it is left in a car or in a car. In such a situation, it is recognized that it is extremely important for practical use that the latent image after exposure is stably stored and the gradation balance is not disturbed, but unfortunately, there is an effective means sufficient to satisfy the conventional technology. I couldn't find it.

[0027]

The object of the present invention is to determine the sensitivity, graininess and sensitivity, especially after long-term storage after exposure,
It is an object of the present invention to provide a silver halide photographic emulsion capable of providing a silver halide photographic photosensitive material excellent in graininess and a silver halide photographic photosensitive material using the same.

[0028]

The above object of the present invention can be achieved by any one of the following constitutional requirements.

In a silver halide photographic emulsion containing silver halide grains and a dispersion medium, the average silver iodide content of the silver halide grains contained in the silver halide photographic emulsion is 2
The molar ratio is not less than 30 mol% and less than 30 mol%, and the average silver iodide content of the outermost layer of the silver halide grains is I ₁ (mol%),
The average silver iodide content of the silver halide grains is I ₂ (mol%)
And I ₁ <I ₂ and the inside of the silver halide grains are reduction-sensitized.

The pH of the protective colloid aqueous solution in which the silver halide grains are grown without using an ammonium compound, and the reduction sensitization is carried out during the growth process of the silver halide grains, is carried out. The silver halide photographic emulsion as described above, wherein the silver halide photographic emulsion is prepared by adjusting the ratio to 7.0 or more.

A silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support, characterized in that at least one of the silver halide emulsion layers contains the above-described silver halide photographic emulsion. A silver halide photographic light-sensitive material.

The present invention will be specifically described below.

The silver halide grains contained in the silver halide photographic emulsion of the present invention may have a regular crystal form such as a cube, octahedron or tetradecahedron, or may have a spherical or plate shape. It may have an irregular crystal form. In these grains, any ratio of {100} plane to {111} plane can be used. It may have a composite form of these crystal forms, and particles of various crystal forms may be mixed. Twinned silver halide grains having two opposing parallel twin planes may be used, in which case tabular silver halide grains are preferred.

A twin is a silver halide crystal having one or more twin planes in one grain. The morphology of twins is classified by Klein and Moiser in the article Photographic Correspondence [Photographishe]. Korrespondentz]
Volume 99, page 99, volume 100, page 57.

In the present invention, when tabular silver halide grains are used, the tabular silver halide grains account for all silver halide grains in the silver halide photographic emulsion containing the tabular silver halide grains. The proportion of the projected area is preferably 60% or more, more preferably 70% or more.

In the present invention, when tabular silver halide grains are used, the average value of the ratio of grain size to grain thickness (also referred to as aspect ratio) is preferably 1.3 or more and less than 5.0, and 1.5 or more and 4.5 or less. Less, more preferably 2.0 or more and less than 4.0. The average aspect ratio is obtained by averaging the ratio of grain size to thickness of all tabular grains.

The twin plane can be observed with a transmission electron microscope. The specific method is as follows. First,
A sample is prepared by coating the silver halide emulsion on the support so that the main planes of the tabular silver halide grains contained are oriented substantially parallel to the support. This is cut with a diamond cutter to obtain a thin section with a thickness of about 0.1 μm. The presence of twin planes can be confirmed by observing this section with a transmission electron microscope.

The average grain size of the silver halide grains of the present invention is 0.
It is preferably 1 μm or more and 5.0 μm or less, more preferably 0.2 μm or more and 3.0 μm or less, and most preferably 0.3 μm or more and 2.0 μm or less.

In the present invention, the average particle size is defined as the particle size ri when ni × ri ³ of the frequency ni and ri ^{3 of} particles having the particle size ri becomes maximum. (3 significant digits, round off the least significant digit) (The number of measured grains shall be indiscriminately 1,000 or more.) The grain size ri here is the main plane in the case of tabular silver halide grains. On the other hand, it is the diameter when the projected image when viewed from the vertical direction is converted into a circular image of the same area, and in silver halide grains having a shape other than tabular silver halide grains,
It is the diameter when a projected image of the silver halide grains is converted into a circular image having the same area.

The grain size ri can be obtained by enlarging a silver halide grain by an electron microscope at a magnification of 10,000 to 70,000 and measuring the grain diameter on the print or the area at the time of projection.

The silver halide photographic emulsion according to the present invention comprises
Any one of a polydisperse emulsion having a wide grain size distribution and a monodisperse emulsion having a narrow grain size distribution may be used, but a monodisperse emulsion is preferable.

A monodisperse emulsion is defined as the width of distribution (%) = [(standard deviation) / (average grain size)] × 100, and the width of distribution is 20%.
It is as follows.

The average particle diameter and standard deviation are obtained from the particle diameter ri defined above.

In the silver halide photographic emulsion of the present invention, any silver halide such as silver iodobromide, silver iodochloride, silver chloroiodobromide and the like used in ordinary silver halides can be used. Are particularly preferably silver iodobromide and silver chloroiodobromide.

The average silver iodide content of the silver halide grains contained in the silver halide photographic emulsion of the present invention is 2 mol% or more 30
It is less than 3 mol% but preferably not less than 3 mol% and less than 20 mol%, more preferably not less than 3 mol% and less than 12 mol%.

The average silver iodide content of the outermost layer of silver halide grains contained in the silver halide photographic emulsion of the present invention is defined as I ₁ (mol%), and the average silver iodide content of the silver halide grains is I. ₂
(Mole%), I ₁ <I ₂ , but preferably I ₁ <0.8 × I ₂ , and more preferably I ₁ <0.6 × I ₂ .

In the silver halide grains contained in the silver halide photographic emulsion of the present invention, it is preferable that a high silver iodide content phase is present inside the grains. The silver iodide content in the high silver iodide content phase is preferably 5 mol% or more and the solid solution limit or less, more preferably 10 mol% or more and the solid solution limit or less, and most preferably 10 mol% or more. It is below the melting limit.

In the present invention, the average silver iodide content of silver halide grains is determined by the EPMA method (Electron Probe Micro Analyze).
r method). Specifically, a sample in which silver halide grains are well dispersed so as not to come into contact with each other is prepared,
By irradiating with an electron beam while cooling to −100 ° C. or lower with liquid nitrogen, and determining the characteristic X-ray intensity of silver and iodine emitted from each silver halide grain, iodide of each silver halide grain is obtained. The silver content can be determined and is measured on at least 50 silver halide grains and their averaged.

Core / shell type grains can also be preferably used in the silver halide grains contained in the silver halide photographic emulsion of the present invention. The core / shell type particle is a particle composed of a core and a shell covering the core, and the shell is formed by one layer or more layers. It is preferable that the core and the shell have different silver iodide contents.

In the present invention, the solid solution limit is represented by the maximum mol% of iodide which can exist as a solid solution in silver halide. Specifically, “The Theory of Photo” edited by TH James
garphic Process "4th edition (published by Macmillan), it can be determined by the method described on page 4. In the case of silver iodobromide, I _MAX (mol%) = 34.5-0.165 (t-25) (t is It can be determined by the temperature (Celsius).

The average silver iodide content I ₁ (mol%) of the outermost surface layer of the silver halide grains contained in the silver halide photographic emulsion of the present invention is preferably more than 0 mol% and not more than 10.0 mol%, More preferably greater than 0 mol% and less than or equal to 8.0 mol%, and most preferably greater than 0 mol% and 6.0.
It is not more than mol%.

In the silver halide grains contained in the silver halide photographic emulsion of the present invention, the inside of the silver halide grains means
In the case of using seed grains for the production of the silver halide grains, it is a portion inside the grain size corresponding to 97% by volume of the silver halide grains and excluding the outermost layer of the silver halide grains. And a portion of the silver halide grains excluding the portion occupied by the seed grains, but preferably inside the grain size corresponding to 90% by volume of the silver halide grains and the silver halide grains. Is a portion excluding the outermost layer and excluding the portion occupied by the seed grains in the silver halide grains, and more preferably inside the grain size corresponding to 70% by volume of the silver halide grains. And a portion excluding the outermost layer of the silver halide grain and a portion excluding the portion occupied by the seed grain in the silver halide grain, and most preferably in the silver halide grain volume. 50% phase And shall apply inside than the particle diameter of a portion excluding the part occupied by the seed particles in a by and said silver halide grains in a portion excluding the outermost layer of the silver halide grains.

In the silver halide grains contained in the silver halide photographic emulsion of the present invention, the inside of the silver halide grains means
When the silver halide grains of the present invention are continuously grown from nucleation without using seed grains for the production of the silver halide grains, the nuclei formed by the nucleation in the silver halide grains Of the silver halide grains, which is inside the grain size corresponding to 97% by volume of the silver halide grains and excludes the outermost layer of the silver halide grains. The silver halide grain is a portion excluding the portion occupied by the nucleus formed by the nucleation in the silver halide grain, and is inside the grain size corresponding to 90% by volume of the silver halide grain, and the silver halide grain. Of the silver halide grain, more preferably 70% of the silver halide grain volume, and more preferably the portion excluding the portion occupied by the nuclei formed by the nucleation in the silver halide grain. Grain The innermost portion of the silver halide grain excluding the outermost layer, most preferably the portion excluding the portion occupied by the nuclei formed by the nucleation in the silver halide grain, and This is a portion inside the grain size corresponding to 50% by volume of the silver halide grains and excluding the outermost layer of the silver halide grains.

The outermost layer referred to in the present invention is the outermost layer of the grain including the outermost surface of the silver halide grain and refers to the depth from the outermost surface of the grain to 50 Å. The halogen composition of the outermost layer of the present invention is determined by the XPS method (X-ray Photoelectron Spectroscopy) as follows.

That is, the sample was cooled to -110 ° C. or lower in an ultrahigh vacuum of 1 × 10 e ^-8 torr or less, and MgKα was irradiated as a probe X-ray with an X-ray source voltage of 15 kV and an X-ray source current of 40 mA, Ag3
Measured for d5 / 2, Br3d, and I3d3 / 2 electrons. The integrated intensity of the measured peak is corrected by the sensitivity factor (Sensitivity Factor), and the halide composition of the surface is determined from the intensity ratio of these.

The XPS method has been disclosed as a method for obtaining the silver iodide content on the surface of silver halide grains in Japanese Patent Laid-Open No. 2-24188. However, when measuring at room temperature,
An accurate silver iodide content in the outermost layer could not be obtained because the sample was destroyed by X-ray irradiation. The present inventors succeeded in accurately obtaining the silver iodide content of the surface layer by cooling the sample to a temperature at which no destruction occurs. As a result, especially for particles such as core / shell particles having different surface and internal compositions, or particles having a high iodine layer or a low iodine layer localized on the outermost surface, the measured value at room temperature is X-ray. It was revealed that the composition differs greatly from the true composition due to decomposition of silver halide by irradiation and diffusion of halide (particularly iodine).

The XPS method used here is specifically as follows.

Emulsion proteolytic enzyme (pronase) 0.05
A weight% aqueous solution was added, and the mixture was stirred at 45 ° C for 30 minutes to decompose gelatin. This is centrifuged to settle the emulsion particles,
Remove the supernatant. Next, distilled water is added to disperse the emulsion particles in distilled water, and the mixture is centrifuged to remove the supernatant. Emulsion particles are redispersed in water and thinly coated on a mirror-polished silicon wafer to obtain a measurement sample. The surface iodide was measured by XPS using the sample thus prepared. The sample is XP to prevent the sample from being destroyed by X-ray irradiation.
It was cooled to −110 to −120 ° C. in the S measurement chamber. MgKα as the X-ray for the probe, X-ray source voltage 15kV, X-ray source current 40
It was irradiated with mA and measured for Ag3d5 / 2, Br3d, and I3d3 / 2 electrons. Sensitivity factor (Sensit
The surface halide composition was calculated from these intensity ratios.

The silver halide grains contained in the silver halide photographic emulsion of the present invention are characterized in that the inside of the grain is reduction-sensitized.

The term "inside grain formation" as used in the present invention means that the growth of a silver halide phase corresponding to the inside of the silver halide grain is started and terminated by the supply of silver ions, halide ions, and / or silver halide grains. The step of forming a silver halide phase up to the above.

The present invention is characterized in that reduction sensitization is intensively performed inside the silver halide grains, and the reduction-sensitized silver halide phase is present inside the silver halide grains as a layer. In addition, the strength of reduction sensitization in the reduction-sensitized silver halide phase is intended to be distributed or inclined in the grain size direction from the center to the surface of the silver halide grain. These reduction sensitized phases inside the silver halide grains indirectly contribute to latent image formation and maintenance of the latent image on the surface of the silver halide grains. It does not directly form a latent image.

Conventionally, a so-called in-shallow latent image type silver halide grain in which a sensitizing nucleus is present just below the surface of the silver halide grain has been reported. However, this is because the sensitizing nucleus itself just below the surface of the silver halide grain is latent. It forms an image and differs from the present invention in form and intention.

While the method generally called silver ripening is carried out on the surface of so-called silver halide grains such as the surface of silver halide grains, a certain point during grain growth or the seed surface, the present invention Has a major feature in that it is carried out for a silver halide layer.

In the present invention, reduction sensitization is preferably carried out at the time of forming the inside of the grain and at the time of forming the above-mentioned high silver iodide content phase.

In the present invention, reduction sensitization is carried out by adding a reducing agent to the protective colloid aqueous solution in which silver halide emulsion grain growth is carried out, or by reducing the protective colloid aqueous solution in which the silver halide grain growth is carried out to pAg 7.0 or less. Under low pAg conditions of
Alternatively, it is carried out by ripening or growing the silver halide grains under a high pH condition of pH 7.0 or more. You may perform these methods in combination.

When a reducing agent is used in the present invention, thiourea dioxide, ascorbic acid and its derivatives, stannous salt, borane compounds, hydrazine derivatives, formamidinesulfinic acid, silane compounds, amines and polyamines, and sulfites are used. Although it can be used, thiourea dioxide, ascorbic acid and derivatives thereof, and stannous salt are preferably used.

When a reducing agent is used in the present invention, the addition amount is preferably 10 ^-2 to 10 ^-8 mol, and more preferably 10 ^-3 to 10 ^-7 mol, per 1 mol of silver halide.

In the present invention, when reduction sensitization is carried out by using a protective colloid aqueous solution for growing silver halide grains under a low pAg condition of pAg 7.0 or less, a silver salt is added to the protective colloid aqueous solution. After addition to a proper pAg, the silver halide grains are preferably aged or grain-grown. The silver salt is preferably a water-soluble silver salt, particularly preferably an aqueous solution of silver nitrate. The pAg during aging is suitably 7.0 or less, preferably 2.0 to 5.0. (Where pAg value is Ag ⁺
It is the common logarithm of the reciprocal of the concentration. In the present invention, when reduction sensitization is carried out by subjecting the protective colloid aqueous solution for growing silver halide grains to a high pH condition of pH 7.0 or more, an alkaline compound is added to the protective colloid aqueous solution. After adjusting the pH to a suitable pH, the silver halide grains are aged or grain-grown. As the alkaline compound, for example, sodium hydroxide, potassium hydroxide, ammonia and the like can be used, but it is preferable to use a compound other than the ammonium compound.

The reduction sensitization in the silver halide photographic emulsion of the present invention was most effectively achieved by keeping the protective colloid aqueous solution in which the silver halide grains were grown under a high pH condition of pH 7.0 or more. .

The reducing agent, the silver salt for reduction ripening, and the alkaline compound may be added by rush addition or over a certain period of time. In this case, constant rate addition or functional addition may be performed. Also, the required amount may be added in several divided portions. Prior to the addition of the soluble silver salt and / or the soluble halide to the reaction vessel, the soluble silver salt and / or the soluble halide may be present in the reaction vessel, or may be mixed in the soluble halide solution and added together with the halide. Furthermore, the addition may be performed separately from the soluble silver salt and the soluble halide.

In the present invention, reduction sensitization is preferably carried out with a protective colloid aqueous solution for growing silver halide grains at a pH of 7.0 or more. The pH is more preferably 7.5 or more and 11.0 or less, and most preferably 8.0 or more and 10.0 or less.

The present invention is characterized in that the reduction sensitization is carried out during the formation of the inside of the grain, but after the formation of the inside of the grain is completed, it is better to remove the environment in which the reduction sensitization is carried out quickly. Good for reducing fog in silver halide grains.

In the present invention, reduction sensitization is carried out by adding a protective colloid aqueous solution in which silver halide grains are grown to a pH of 7.0 or more.
When it is carried out under the pH condition, the pH is gradually lowered in the process of shell growth after the formation of the inside of the grain and the pH is adjusted to 5.0 after the completion of silver halide grain growth and before desalting.
It is preferable to control the pH so as to be ˜6.5. More preferably, the pH is promptly lowered to 6.5 or less by an acid immediately after the formation of the inside of the particle, and further preferably 5.0 to
It is better to lower it to 6.0. Acetic acid and nitric acid are preferably used as the acid.

In the present invention, when reduction sensitization is carried out by subjecting a protective colloid aqueous solution for growing silver halide grains to a low pAg condition of pAg 7.0 or less, pAg7.
Immediately after ripening or growth inside the silver halide grains under a low pAg condition of 0 or less, the pAg was rapidly increased.
Is preferably returned to the proper growth region of the original silver halide grain to carry out growth after the formation of the inside of the grain.

In the present invention, when the reduction sensitization is carried out by adding a reducing agent, the reducing agent is added immediately before the growth of the inside of the silver halide grain to ripen the inside of the silver halide grain or the inside of the grain. It is advisable to deactivate the reducing agent immediately after the growth of. In order to deactivate the reducing agent, it is preferable to use the following oxidizing agent.

Hydrogen peroxide (water) and its adducts: H2O2,
NaBO2, H2O2-3H2O, 2NaCO3-3H2O2, Na4P2O7-2H2O2, 2Na2
SO4-H2O2-2H2O etc. Peroxy acid salt: K2S2O3, K2C2O
3, K4P2O3, K2 [Ti (O2) C2O4] -3H2O. Peracetic acid, ozone,
Examples include I2 and thiosulfonic acid.

In the emulsion of the present invention, the above oxidizing agent can be used for purposes other than deactivating the reducing agent. The amount of oxidant added depends on the type of reducing agent, reduction sensitization conditions, oxidant addition timing, oxidant addition conditions, etc., but 10 ^-3 to 10 ^-10 per mol of reducing agent used. ⁵ mol is preferred.

The oxidizing agent may be added at any time during the silver halide emulsion manufacturing process. It can also be added prior to the addition of the reducing agent.

As a method of adding an oxidizing agent, a method of adding an additive to a silver halide emulsion can be applied in the art. For example, it can be dissolved in advance in a suitable organic solvent represented by alcohols or added as an aqueous solution.

After adding the oxidizing agent, a reducing substance may be newly added to neutralize the excess oxidizing agent. These reducing substances are substances capable of reducing the above-mentioned oxidizing agent, sulfinic acids, di- and trihydroxybenzenes, chromanes, hydrazine and hydrazides, p-phenylenediamines, aldehydes, aminophenols, Examples include endiols, oximes, reducing sugars, phenidones, sulfites, and ascorbic acid derivatives. The amount of the reducing substance is preferably 10 ^-3 to 10 ³ mol amount 1 mole of oxidizing agent used is.

Various methods well known in the art can be used to produce the silver halide grains of the present invention. That is, the single jet method, the double jet method, the triple jet method and the like can be used in any combination. Further, a method of controlling pH and pAg in the liquid phase in which silver halide is produced according to the growth rate of silver halide can also be used.

When seed grains are used to form the silver halide grains contained in the silver halide photographic emulsion of the present invention, the seed grains are regular crystals such as cubic, octahedral and tetradecahedral. It may have a shape, or may have an irregular crystal shape such as a sphere or a plate. In these grains, any ratio of {100} plane to {111} plane can be used. It may have a composite form of these crystal forms, and particles of various crystal forms may be mixed. The seed grains are preferably twinned silver halide seed grains having two opposing parallel twin planes, and monodisperse spherical seed grains are also preferably used. It is most preferable to use twin seed particles described in Japanese Patent Application No. 3-341164.

The silver halide photographic emulsion of the present invention is prepared by the acidic method,
Although it may be produced by any of the neutral method and the ammonia method, an acidic method or a neutral method in which the growth of silver halide grains is performed without using an ammonium compound is preferable,
The silver halide emulsion of the present invention was most effectively achieved by the neutral method carried out without the ammonium compound.

In the present invention, the ammonium compound refers to a general compound that releases ammonium ions in an aqueous solution, and refers to ammonia water, an ammonium compound, an ammonium salt, an ammonia complex salt, an ammonium oxide, etc., and is the most widely used. Is ammonia water.

In the present invention, a known silver halide solvent such as thioether or thiourea can be used if necessary, as long as it is not an ammonium compound.

In the production of the silver halide photographic emulsion of the present invention, the halide ion and the silver ion may be mixed at the same time or one of them may be present while the other is mixed. Also, considering the critical growth rate of silver halide crystals,
In addition, the halide ion and silver ion are mixed in the pAg, pH
It is also possible to control and add them sequentially or simultaneously. The conversion method may be used in any step of silver halide formation to change the silver halide composition of the silver halide grains.

In the production of the silver halide photographic emulsion of the present invention, a cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt (including a complex salt is included in the process of forming and / or growing the silver halide grain. ), A rhodium salt (including a complex salt), an iron salt (including a complex salt), and a metal ion is added to contain these metal elements inside and / or on the surface of the silver halide grain. be able to.

In the production of the silver halide photographic emulsion of the present invention, the dispersion medium means gelatin or other substance capable of forming a protective colloid.

In the present invention, when gelatin is used as the dispersion medium, the gelatin may be lime-treated or acid-treated. Details of the gelatin manufacturing method are described in "The Macromolecular Chemistry of Gelatin" by Arthur Weiss (Academic Press, 1964). Examples of substances capable of forming protective colloids other than gelatin include gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein, cellulose such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfate. Derivatives, sodium alginate, sugar derivatives such as starch derivatives, polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-n-vinylpyrrolidone, polyacrylic acid, polyacrylamide, polymethacrylic acid, polyvinylimidazole, polyvinylpyrazole, etc. There may be mentioned various synthetic or semi-synthetic hydrophilic polymeric substances such as copolymers. In the present invention, it is preferable to use gelatin as the dispersion medium.

In the present invention, the protective colloid aqueous solution in which silver halide grains are grown is an aqueous solution in which silver halide grains are grown and is a protective colloid made of gelatin or another substance capable of forming a hydrophilic colloid. Is formed in the aqueous solution, and preferably an aqueous solution containing colloidal protective gelatin.

In the silver halide photographic emulsion of the present invention, unnecessary soluble salts may be removed at the end of the growth of silver halide grains, or may be contained therein. To remove the salts, use Research Disclosure (Re
search Disclosure Hereinafter abbreviated as RD. ) No. 17643, Item II.

In the silver halide photographic emulsion of the present invention, the average silver iodide content I ₁ (mol%) of the silver halide grains contained in the silver halide photographic emulsion is determined by the average silver iodide content of the silver halide grains. As a specific method for reducing the content to less than I ₂ (mol%), the silver halide fine grains can be used after desalting in the production process of the silver halide photographic emulsion and before chemical sensitization or spectral sensitization. Was most effectively produced by the method of forming at least a part of the outermost surface layer of the silver halide grains contained in the silver halide photographic emulsion or the outermost shell layer including the outermost surface layer.

In the present invention, the process for producing a silver halide photographic emulsion includes the steps of nucleation and growth of silver halide fine grains included in the process for producing a silver halide photographic emulsion, and the seed grains when seed grains are used. From the growth process to the desalting process, the silver halide grain dispersion process, the chemical sensitization process and the spectral sensitization process, including the coating solution preparation process and the silver halide photographic material manufacturing process after the coating process. I can't.

In the present invention, when silver halide fine grains are used, the silver halide fine grains may be prepared in advance prior to the preparation of the silver halide photographic emulsion, or in parallel with the preparation of the silver halide photographic emulsion. You may prepare it. When the latter is prepared in parallel, JP-A 1-183417 and JP-A
As described in No. 2-44335, a method of producing fine silver halide grains by using a mixer separately provided outside the reaction vessel in which the silver halide grains are formed can be used. As described in Japanese Patent Application No. 2-314891, a preparation container is provided after formation of fine particles, and the silver halide fine particle emulsion is supplied to the reaction container while being prepared according to the growth environment in the reaction container. Is desirable.

As a method for preparing the fine silver halide grains, a production method for forming grains in an acidic or neutral environment (pH ≦ 7) is preferable.

To produce the fine silver halide grains, a water-soluble silver salt containing silver ions and a water-soluble alkali halide containing halide ions may be mixed while appropriately controlling the supersaturation factor. Regarding the control of the supersaturation factor, JP-A-63-92942 or JP-A-63-311244
You can refer to the description such as the issue.

The pAg forming the fine silver halide grains used in the present invention is preferably 3.0 or more, more preferably 5.0 or more, and further preferably 5.0 or more in order to suppress generation of reduced silver nuclei in the silver halide fine grains themselves. It is 8.0 or higher.

The temperature at which the fine silver halide grains are formed is preferably 50 ° C. or lower, preferably 40 ° C. or lower, and more preferably 35 ° C. or lower. Ordinary polymer gelatin can be used as a protective colloid when the silver halide grains are formed using this method.

When the silver halide fine grains are formed at a low temperature, the Ostwald ripening after the formation of the silver halide fine grains can be further suppressed, but the gelatinization is likely to occur at a low temperature. It is preferable to use low molecular weight gelatin as described in JP-A-166442, a synthetic molecular compound having a protective colloid action on silver halide grains, or a natural polymer compound other than gelatin. The concentration of protective colloid is preferably 1
It is at least wt%, more preferably at least 2 wt%, and even more preferably at least 3 wt%.

The silver halide fine grains supplied to the aqueous solution containing the protective colloid for forming the silver halide grains grow the silver halide grains due to the Ostwald ripening effect. Since the fine silver halide grains have a fine grain size, they are easily dissolved and become silver ions and halide ions again to cause uniform growth.

When silver halide fine grains are used in the present invention, the size of the silver halide fine grains is preferably 0.1 μm or less, more preferably 0.05 μm or less.

When silver halide fine particles are used in the present invention, a method in which the silver halide fine particles are dispersed in an aqueous solution containing a protective colloid and then added is preferably used.

The fine silver halide grains may be added by funnel addition or function addition using a pump or the like.
It may be added in two or more portions, and after the addition of the silver halide fine grains, ripening may be carried out if necessary.

In the production of the silver halide photographic emulsion according to the present invention, the conditions other than the above are described in JP-A-61-664.
No. 3, No. 61-14630, No. 61-112142, No. 62-157024,
62-18556, 63-92942, 63-151618, 63-16
Appropriate conditions can be selected with reference to 3451, 63-220238, 63-311244 and the like.

When a color photographic light-sensitive material is constructed using the silver halide photographic emulsion of the present invention, the silver halide photographic emulsion used is one which has been physically ripened, chemically ripened and spectrally sensitized. The additives used in such a process are Research Disclosure No.17643, No.18716 and N.
o.308119 (Respectively RD17643, RD18716 and RD30811
(Abbreviated as 9)). The following shows the locations.

[Item] [Page of RD308119] [RD17643] [RD18716] Chemical sensitizer 996 III-A 23 648 Spectral sensitizer 996 IV-A-A, B, C, D, H, I, J Item 23-24 648-9 Supersensitizer 996 IV-A-E, J Item 23-24 648-9 Antifoggant 998 VI 24-25 649 Stabilizer 998 VI 24-25 649 Silver halide of the present invention Known photographic additives which can be used when a color photographic light-sensitive material is constituted by using a photographic emulsion are also described in the following Research Disclosure.
Below are the relevant locations.

[Items] [Page of RD308119] [RD17643] [RD18716] Color turbidity inhibitor 1002 VII-I 25 650 Dye image stabilizer 1001 VII-J 25 Whitening agent 998 V 24 UV absorber 1003 VIII- C, XIII C Item 25-26 Light absorber 1003 VIII 25-26 Light scattering agent 1003 VIII Filter dye 1003 VIII 25-26 Binder 1003 IX 26 651 Antistatic agent 1006 XIII 27 650 Hardener 1004 X 26 651 Plasticizer 1006 XII 27 650 Lubricants 1006 XII 27 650 Activators / coating aids 1005 XI 26 to 27 650 Matte agents 1007 XVI Developer (included in light-sensitive material) Item 1011 XXB Color photographic light-sensitive using the silver halide photographic emulsion of the present invention Various couplers may be used in constructing the material, specific examples of which are described in Research Disclosure below.

The following is the relevant description part.

[Item] [Page of RD308119] [RD17643] Yellow coupler 1001 VII-D item VIIC-G item Magenta coupler 1001 VII-D item VIIC-G item Cyan coupler 1001 VII-D item VIIC-G item Colored coupler 1002 Item VII-G Item VIIG Item DIR coupler 1001 Item VII-F Item VIIF Item BAR coupler 1002 Item VII-F Other useful residues Release coupler 1001 Item VII-F Alkali-soluble coupler 1001 Item VII-E Silver halide photograph of the present invention Additives used in constructing a color photographic light-sensitive material using an emulsion can be added by the dispersion method described in RD308119XIV.

When a silver halide photographic emulsion of the present invention is used to form a color photographic light-sensitive material, the above-mentioned RD17643 28 is used.
The supports described on page RD18716 pp. 647-8 and RD308119 XVII can be used.

The color photographic light-sensitive material using the silver halide photographic emulsion of the present invention may be provided with auxiliary layers such as a filter layer and an intermediate layer described in the above-mentioned item RD308119VII-K.

The color photographic light-sensitive material using the silver halide photographic emulsion of the present invention can have various layer constitutions such as the forward layer, the reverse layer and the unit constitution described in the above item RD308119VII-K.

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

The color photographic light-sensitive material using the silver halide photographic emulsion of the present invention is described in RD17643, pages 28 to 29, RD18716 61.
Development can be carried out by a usual method described on page 5 and XIX of RD308119.

[0115]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

Example 1 (Preparation of Twin Seed Emulsion (T-1)) Seed from Japanese Patent Application No. 3-341164, a seed having two parallel twin planes was prepared by the following method. An emulsion (T-1) was prepared.

Solution A Oscein gelatin 80.0 g Potassium bromide 47.4 g HO (CH ₂ CH ₂ O) _m [CH (CH ₃ ) CH ₂ O] _19.8 (CH ₂ CH ₂ O) _n H (m ± n = 9.77) 10% by weight methanol solution 0.48 g with water 8000 ml solution B silver nitrate 1200 g with water 1600 ml solution C ossein gelatin 32.2 g potassium bromide 790 g potassium iodide 70.34 g water 1600 ml solution D ammonia water 470 ml JP-A-62-160128 Using the stirrer described, solution B and solution C were added to solution A that was vigorously stirred at 40 ° C. for 7.7 minutes by the double jet method to generate nuclei. During this time, pBr was kept at 1.60.

Thereafter, the temperature was lowered to 20 ° C. over 35 minutes. Furthermore, the solution D was added in 1 minute, and the aging was continued for 5 minutes. The KBr concentration during aging was 0.03 mol / l, and the ammonia concentration was 0.66 mol / l.

After completion of the aging, the pH was adjusted to 6.0 and desalting was carried out according to a conventional method. When the seed emulsion grains were observed with an electron microscope, the average grain size of the seed emulsion grains was 0.225 μm, 2
The parallel twin plane ratio was 75% in the total number of grains.

(Preparation of Comparative Emulsion (Em-1)) A comparative emulsion (Em-1) was prepared using the following 5 kinds of solutions.

(Solution A-1) Ocein gelatin 66.5 g Distilled water 3227 ml HO (CH ₂ CH ₂ O) _m (CHCH ₃ CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10 Weight% methanol solution 2.50 ml Seed emulsion (T-1) 98.5 g Distilled water to 3500 cc.

(Solution B-1) 3.5N Silver Nitrate Aqueous Solution 4702.0 ml (Solution C-1) Potassium Bromide 2499.0 g Distilled water makes 6000 cc.

(Solution D-1) A fine grain emulsion comprising 3% by weight of gelatin and silver iodide grains (average grain size 0.05 μm) (preparation method is shown below) 1897.0 g * 0.06 mol of potassium iodide 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 2000 ml of 7.06 mol of potassium iodide were added to 5000 ml of 6.0 wt% gelatin solution. The temperature during fine particle formation was controlled at 40 ° C. The finished weight was 12.53 kg.

(Solution E-1) 1.75N Potassium Bromide Aqueous Solution Required amount Solution A-1 was added to a reaction vessel and stirred vigorously.
Solution B-1 to solution D-1 were added according to the combination shown in Table 1 by the simultaneous mixing method to grow a seed crystal to prepare a core / shell type silver halide emulsion.

Here, (1) solution B-1, solution C-1 and solution D-1 addition rates, (2) solution B-1 and solution C-1
The addition rate of was changed like a function with respect to time so as to correspond to the critical growth rate of silver halide grains,
In addition to the growing seed crystals, the addition rate was controlled so that small particles would not be generated and polydispersion due to Ostwald ripening would not occur.

The temperature of the solution in the reaction vessel was controlled at 75 ° C. and the pAg was controlled at 8.8 over the entire area of crystal growth. pA
Solution E-1 was added as needed for g control. The pH was not controlled but was maintained in the pH range of 5.0-6.0 throughout grain growth.

Table 1 also shows the amount of silver added at that time and the silver iodide content of the silver halide phase during formation with respect to the addition time of the addition solution.

After grain growth, desalting treatment was performed according to the method described in Japanese Patent Application No. 4-59351, and a 20% by weight gelatin aqueous solution was added.
Add 1.19 L and disperse at 50 ° C for 30 minutes, then add pH at 40 ° C.
5.80 and pBr were adjusted to 3.55.

The silver halide grains contained in the obtained silver halide emulsion were monodisperse tabular silver halide grains having an average grain size of 1.34 μm (diameter in terms of projected area circle), an average aspect ratio of 2.6 and a grain size distribution of 18%. Met.

[0130]

[Table 1]

(Preparation of Comparative Emulsion (Em-2)) Comparative Emulsion (Em-2)
In the preparation of m-1), after grain growth and before desalting, 10
A comparative emulsion (Em-2) was prepared in exactly the same manner except that the pH was adjusted to 8.5 at 75 ° C. with an aqueous solution of potassium hydroxide at 25 ° C., ripened for 20 minutes, and then adjusted to 5.8 with acetic acid.

(Preparation of Emulsion (Em-3) of the Present Invention) Solution B-1 to Solution D-1 in the preparation of comparative emulsion (Em-1)
52.47 minutes after the start of the addition, the pH was adjusted to 8.0 with a 10% aqueous potassium hydroxide solution, and after grain growth, desalting treatment was performed according to the method described in Japanese Patent Application No. 4-59351. Add 1.19 L of a gelatin solution of 1% by weight in weight and disperse at 50 ° C for 15 minutes, then pBr with 3.5N potassium bromide aqueous solution at 50 ° C.
Is adjusted to 1.5, and the following solution H-0 is added to the stirring silver halide emulsion for 30 seconds, followed by stirring for 20 minutes, and then pH is adjusted to 5.80 and pBr to 3.55 at 40 ° C. The emulsion (Em-3) of the present invention was prepared in the same manner except the above. The history of pH in the reaction vessel was as follows.

Time (minutes) from the start of addition of Solution B-1 to Solution D-1 52.47 76.48 150.13 176.09 239.00 pH 8.00 7.51 6.40 6.36 5.84 (Solution H-0) 3 wt% gelatin And a fine grain emulsion consisting of silver bromide grains (average particle size 0.04 μm) (preparation method is shown below) 0.212 mol * 6.06% by weight gelatin solution containing 0.06 mol potassium bromide 5000 ml, 7.06 mol silver nitrate An aqueous solution containing 7.06
2000 ml of an aqueous solution containing each mole of potassium bromide was added over 10 minutes. The temperature during fine particle formation was controlled at 30 ° C.
The pH during fine particle formation was controlled to 3.0 using nitric acid, and after forming fine particles, the pH was adjusted to 6.0 using aqueous sodium carbonate solution.

(Preparation of Emulsion (Em-4) of the Present Invention) Solution B-1 to Solution D-1 in the preparation of comparative emulsion (Em-1)
52.47 minutes after the start of the addition, pH was adjusted to 9.0 using a 10% aqueous potassium hydroxide solution, and after grain growth, desalting treatment was performed according to the method described in Japanese Patent Application No. 4-59351, Add 1.19 L of a gelatin solution of 1% by weight in weight and disperse at 50 ° C for 15 minutes, then pBr with 3.5N potassium bromide aqueous solution at 50 ° C.
Was adjusted to 1.5, and the solution H-0 used in the preparation of the emulsion (Em-3) of the present invention was added to the stirring silver halide emulsion at 30%.
Add for 2 seconds, then stir for 20 minutes and then add pH at 40 ℃.
The emulsion (Em-4) of the present invention was prepared in exactly the same manner except that the ratio was adjusted to 5.80 and the pBr was adjusted to 3.55. PH in the reaction vessel
The history of was:

Time (minutes) from the start of addition of Solution B-1 to Solution D-1 52.47 76.48 150.13 176.09 239.00 pH 9.00 8.43 7.16 6.89 6.32 (emulsion of the invention (Em-5) in the reaction vessel Preparation) In the preparation of the comparative emulsion (Em-1), 52.47 minutes after the addition of Solution B-1 to Solution D-1 was started, a 10% aqueous potassium hydroxide solution was used to p.
After adjusting H to 9.0 and 150.13 minutes after the addition of solution B-1 to solution D-1 was started, the pH was adjusted to 6.0 using acetic acid, and after particle growth, Japanese Patent Application No. 4-59351 was used. After desalting according to the method described in 1., 1.19 L of 20% by weight gelatin aqueous solution was added and dispersed at 50 ° C for 15 minutes, and then 3.5 at 50 ° C.
The pBr was adjusted to 1.5 with an aqueous potassium bromide solution, and the solution H-0 used in the preparation of the emulsion (Em-3) of the present invention was added to the stirring silver halide emulsion for 30 seconds. The emulsion (Em-5) of the present invention was prepared in exactly the same manner except that the pH was adjusted to 5.80 and the pBr was adjusted to 3.55 at 40 ° C. after stirring for 20 minutes. The history of pH in the reaction vessel was as follows.

Time (minutes) from the start of addition of Solution B-1 to Solution D-1 52.47 76.48 150.13 → 150.13 176.09 239.00 pH 9.00 8.46 7.22 6.00 5.94 5.82 in the reaction vessel (Emulsion of the present invention (Em- Preparation of 6)) In the preparation of the comparative emulsion (Em-1), the addition of Solution B-1 to Solution D-1 was started 52.47 minutes later, the addition was interrupted, and the pAg was adjusted to 6.0 using a 3.5N silver nitrate aqueous solution. After adjusting and aging for 10 minutes, pAg was returned to 8.8 with a 3.5N potassium bromide aqueous solution to prepare solution B-1 to solution D-1.
150.13 minutes after the addition of Solution B-1 to Solution D-1 was started, the pH was adjusted to 6.0 with acetic acid, and after particle growth, Japanese Patent Application No. 4-59351 was added. Desalted according to the method described, 20% by weight gelatin aqueous solution
Add 1.19L and disperse for 15 minutes at 50 ℃, then 3.5N at 50 ℃
The pBr was adjusted to 1.5 with an aqueous potassium bromide solution, and the solution H-0 used in the preparation of the emulsion (Em-3) of the present invention was added to the stirring silver halide emulsion for 30 seconds, followed by addition of 20 The emulsion (Em-6) of the present invention was prepared in exactly the same manner except that pH was adjusted to 5.80 and pBr was adjusted to 3.55 at 40 ° C. after stirring for 40 minutes.

(Preparation of Emulsion (Em-7) of the Present Invention) Solution B-1 to Solution D-1 in the preparation of comparative emulsion (Em-1)
The addition was discontinued 52.47 minutes after the start of the addition, the pAg was adjusted to 5.0 with a 3.5N silver nitrate aqueous solution and aged for 10 minutes, and then the pAg was returned to 8.8 with a 3.5N potassium bromide aqueous solution to prepare solution B.
-1 to Solution D-1 was restarted, and after grain growth, desalting treatment was carried out according to the method described in Japanese Patent Application No. 4-59351, and 1.19 L of 20% by weight gelatin aqueous solution was added to the solution. After dispersing for 30 minutes, pBr with a 3.5N potassium bromide aqueous solution at 50 ° C.
Was adjusted to 1.5, and the solution H-0 used in the preparation of the emulsion (Em-3) of the present invention was added to the stirring silver halide emulsion at 30%.
Add for 2 seconds, stir for 20 minutes, and p at 40 ℃.
An emulsion (Em-7) of the present invention was prepared in exactly the same manner except that H was adjusted to 5.80 and pBr was adjusted to 3.55.

(Preparation of Comparative Emulsion (Em-8)) A comparative octahedral twin monodisperse emulsion E was prepared by using the following seven kinds of solutions.
m-8 was prepared.

(Solution A-2) Ocein gelatin 268.2 g distilled water 4.0 l HO (CH ₂ CH ₂ O) _m [CH (CH ₃ ) CH ₂ O] _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10% by weight methanol solution 1.5 ml Seed emulsion (T-1) 0.341 mol 28% by weight ammonia solution 528.0 ml 56% by weight acetic acid solution 795.0 ml 0.001 mol methanol solution containing 50.0 ml distilled water to 5930.0 ml (Solution B-2) 3.5N ammoniacal silver nitrate aqueous solution.

(However, the pH was adjusted to 9.
(Solution C-2) 3.5N potassium bromide aqueous solution containing 4.0% by weight of gelatin (Solution D-2) Fine particles consisting of 3% by weight of gelatin and silver iodide grains (average particle size 0.05 μm) Emulsion (Preparation method is shown below) 0.844 mol * To 6.0 ml of a 6.0% by weight gelatin solution containing 0.06 mol potassium iodide, 2000 ml of an aqueous solution containing 7.06 mol silver nitrate and 7.06 mol potassium iodide, respectively Added over minutes. The pH during the formation of fine particles is 2.0 using nitric acid, and the temperature is 40
Controlled to ° C. After forming the particles, the pH was adjusted to 6.0 using an aqueous sodium carbonate solution. (Solution E-2) 0.73 mol of a fine grain emulsion composed of silver iodide grains (average grain size 0.04 μm) prepared in the same manner as the silver iodide fine grain emulsion described in Solution D. However, the temperature during fine grain formation was 30 Controlled to ° C.

(Solution F-2) 1.75N potassium bromide aqueous solution (Solution G-2) 56% by weight aqueous acetic acid solution Solution A-2 kept at 70 ° C. in the reaction vessel was mixed with solution B-2,
Solution C-2 and solution D-2 were added by the simultaneous mixing method over a period of 163 minutes, followed by addition of solution E-2 to 12
The seed crystal was grown to 1.349 μm by constant rate addition alone in a minute.

Here, the addition rates of the solution B-2 and the solution C-2 were changed in a function-like manner with respect to time so as to correspond to the critical growth rate, and the generation of small particles other than the growing seed crystal and It was added at an appropriate addition rate so as not to cause polydispersion due to Ostwald ripening. The solution D-2, that is, the silver iodide fine grain emulsion was supplied by changing the rate ratio (molar ratio) with the aqueous ammoniacal silver nitrate solution with respect to the particle size (addition time) as shown in Table 2 to form a multiple structure. A core / shell type silver halide emulsion having the above was prepared.

Further, by using the solutions F-2 and G-2, pAg and pH during crystal growth were controlled as shown in Table 2. The pAg and pH were measured using a silver sulfide electrode and a glass electrode according to a conventional method.

After grain formation, desalting treatment was carried out according to the method described in Japanese Patent Application No. 4-59351, gelatin was then added and redispersed, and pH was adjusted to 5.80 and pAg was adjusted to 8.06 at 40 ° C. From the scanning electron micrograph of the obtained emulsion grains, the average grain size was 1.28.
It was confirmed to be an octahedral twin monodisperse emulsion having a micrometer and a distribution of 10.3%.

[0145]

[Table 2]

(Preparation of Comparative Emulsion (Em-9)) Comparative Emulsion (Em-9)
m-8) in the preparation of Japanese Patent Application No. 4-59351 after particle growth.
After desalting according to the method described in No. 1, 1.19 L of 20% by weight gelatin aqueous solution was added and dispersed at 50 ° C for 15 minutes, and then 50
Adjust pBr to 1.5 with 3.5N potassium bromide aqueous solution at ℃,
Solution H-1 shown below was added to the stirred silver halide emulsion.
After 30 minutes, 10 minutes later, the following solution I-1 was added for 30 seconds, 10 minutes later, the following solution J-1 was added for 30 seconds, and after stirring for 20 minutes, the pH was 5.80 at 40 ° C. , PBr to 3.55, but in the same manner as Comparative Emulsion (Em-9)
Was prepared.

(Solution H-1) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.127 mol (Solution I-1) 3% by weight of gelatin and a fine grain emulsion comprising silver bromide grains (average grain size 0.04 μm) are prepared as follows. 0.127 mol (Solution J-1) A fine grain emulsion composed of 3% by weight of gelatin and silver bromide particles (average particle size 0.04 μm) (preparation method is shown below) 0.212 mol * 0.06 mol of potassium bromide 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 7.06 mol of potassium bromide were added to 5000 ml of a 6.0 wt% gelatin solution over 10 minutes. The temperature during fine particle formation was controlled at 30 ° C. The pH during fine particle formation was controlled to 3.0 using nitric acid, and after forming fine particles, the pH was adjusted to 6.0 using aqueous sodium carbonate solution.

(Preparation of Emulsion (Em-10) of the Present Invention) Solution B-1 to Solution D-1 in the preparation of comparative emulsion (Em-9)
52.47 minutes after the start of addition of the emulsion (Em-1 of the present invention) in exactly the same manner except that the following solution (K-1) was added.
0) was prepared.

(Solution K-1) Aqueous solution containing 1 × 10 ⁻⁶ mol of thiourea dioxide corresponding to 1 mol of emulsion (Em-9) 100.0 ml Emulsions (Em-1) to (Em- The characteristics of 10) are shown.

[0150]

[Table 3]

The emulsions (Em-1) to (Em-10) were optimally chemically sensitized. Each of these emulsions was designated as (Emulsion A) and used in the following sample formulation.

Multilayer color photographic light-sensitive material samples 11 to 20 were prepared by sequentially forming layers having the following compositions on the triacetyl cellulose film support from the support side.

Unless otherwise specified, the addition amount indicates the number of grams per 1 m ² . The silver halide and colloidal silver are shown in terms of silver, and the sensitizing dye is shown in the number of moles per mole of silver.

First layer: antihalation layer Black colloidal silver 0.16 Ultraviolet absorber (UV-1) 0.20 High boiling point organic solvent (Oil-1) 0.16 Gelatin 1.23 Second layer: Intermediate layer Compound (SC-1) 0.15 High boiling point Organic solvent (Oil-2) 0.17 Gelatin 1.27 Third layer; low-sensitivity red-sensitive layer Silver iodobromide emulsion (average grain size 0.38 μm, silver iodide content rate 8.0 mol%) 0.50 Silver iodobromide emulsion (average grain size) 0.27 μm, silver iodide content 2.0 mol%) 0.21 Sensitizing dye (SD-1) 2.8 × 10 ^-4 Sensitizing dye (SD-2) 1.9 × 10 ^-4 Sensitizing dye (SD-3) 1.9 × 10 ^-5 Sensitizing dye (SD- ⁴ ) 1.0 × 10 ^-4 Cyan coupler (C-1) 0.48 Cyan coupler (C-2) 0.14 Colored cyan coupler (CC-1) 0.021 DIR compound (D-1) 0.020 High boiling point Solvent (Oil-1) 0.53 Gelatin 1.30 4th layer; Medium-sensitive red-sensitive layer Silver iodobromide emulsion (average grain size 0.52 μm, silver iodide content 8.0 mol%) 0.62 Silver bromide emulsion (average grain size 0.38 .mu.m, a silver iodide content of 8.0 mol%) 0.27 Sensitizing dye (SD─1) 2.3 × 10 ^-4 Sensitizing dye (SD─2) 1.2 × 10 ^-4 Sensitizing dye (SD-3) 1.6 × 10 ^-5 Sensitizing dye (SD- ⁴ ) 1.2 × 10 ^-4 Cyan coupler (C-1) 0.15 Cyan coupler (C-2) 0.18 Colored cyan coupler (CC-1) 0.030 DIR compound (D-1) 0.013 High boiling point solvent (Oil-1) 0.30 Gelatin 0.93 Fifth layer; high-sensitivity red-sensitive layer Silver iodobromide emulsion (average grain size 1.0 μm, silver iodide content 8.0 mol%) 1.27 Sensitization Dye (SD-1) 1.3 × 10 ^-4 Sensitizing dye (SD-2) 1.3 × 10 ^-4 Sensitizing dye (SD-3) 1.6 × 10 ^-5 Cyan coupler (C-2) 0.12 Colored cyan coupler (CC ─ 1) 0.013 High boiling point solvent (Oil -1) 0.14 Gelatin 0.91 6th layer; Intermediate layer Compound (SC-1) 0.09 High boiling point solvent (Oil-2) 0.11 Gelatin 0.80 7th layer; Low sensitivity green sensitive layer Iodour Silver halide emulsion (average grain size 0.38 μm Silver iodide content 8.0 mol%) 0.61 Silver iodobromide emulsion (average particle diameter 0.27 [mu] m, silver iodide content 2.0 mol%) 0.20 Sensitizing dye (SD─4) 7.4 × 10 ^-5 Sensitizing dye (SD -5) 6.6 × 10 ^-4 Magenta coupler (M-1) 0.18 Magenta coupler (M-2) 0.44 Colored magenta coupler (CM-1) 0.12 High boiling point solvent (Oil-2) 0.75 Gelatin 1.95 8th layer; Medium sensitivity green-sensitive layer silver iodobromide emulsion (average grain size 0.59 .mu.m, a silver iodide content of 8.0 mol%) 0.87 sensitizing dye (SD─6) 2.4 × 10 ^-4 sensitizing dye (SD─7) 2.4 × 10 ^{- 4} Magenta coupler (M-1) 0.058 Magenta coupler (M-2) 0.13 Colored magenta coupler (CM-1) 0.070 DIR compound (D-2) 0.025 DIR compound (D-3) 0.002 High boiling point solvent (Oil-2) 0.50 gelatin 1.00 ninth layer: high sensitivity green-sensitive layer silver iodobromide emulsion (emulsion A) 1.27 sensitizing dye (SD─6) 1.4 × 10 ^-4 sensitizing dye (SD─7) 1.4 × 10 ^-4 magenta Puller (M-2) 0.084 Magenta coupler (M-3) 0.064 Colored magenta coupler (CM-1) 0.012 High boiling point solvent (Oil-1) 0.27 High boiling point solvent (Oil-2) 0.012 Gelatin 1.00 10th layer; Yellow filter Layer Yellow colloidal silver 0.08 Color stain inhibitor (SC-2) 0.15 Formalin scavenger (HS-1) 0.20 High boiling point solvent (Oil-2) 0.19 Gelatin 1.10 11th layer; Intermediate layer Formalin scavenger (HS-1) 0.20 Gelatin 0.60 12th layer; low-sensitivity blue-sensitive layer Silver iodobromide emulsion (average grain size 0.38 μm, silver iodide content 8.0 mol%) 0.22 Silver iodobromide emulsion (average grain size 0.27 μm, silver iodide content 2.0 mol) %) 0.03 Sensitizing dye (SD-8) 4.9 × 10 ^-4 Yellow coupler (Y-1) 0.75 DIR compound (D-1) 0.010 High boiling point solvent (Oil-2) 0.30 Gelatin 1.20 13th layer; Medium sensitivity blue Sensitive layer Silver iodobromide emulsion (average grain size 0.59 μm, silver iodide content 8.0 mol%) 0.30 Sensitizing dye (SD-8) 1.6 × 10 ^-4 Sensitizing dye (SD-9) 7.2 × 10 ^-5 Yellow coupler (Y-1) 0.10 DIR compound (D-1) 0.010 High boiling solvent (Oil-2) ) 0.046 Gelatin 0.47 14th layer; high-sensitivity blue-sensitive layer Silver iodobromide emulsion (average grain size 1.0 μm, silver iodide content 8 mol%) 0.85 Sensitizing dye (SD-8) 7.3 × 10 ^-5 Dye-sensitizing agent (SD-9) 2.8 × 10 ^-5 Yellow coupler (Y-1) 0.11 High boiling point solvent (Oil-2) 0.046 Gelatin 0.80 15th layer; 1st protective layer Silver iodobromide emulsion (average grain size 0.08 μm , Silver iodide content 1.0 mol%) 0.40 UV absorber (UV-1) 0.065 UV absorber (UV-2) 0.10 High boiling point solvent (Oil-1) 0.07 High boiling point solvent (Oil-3) 0.07 Formalin scavenger ( HS-1) 0.40 Gelatin 1.31 16th layer; 2nd protective layer Alkali-soluble matting agent (average particle size 2 μm) 0.15 Polymethylmethacrylate (average particle size 3 μm) 0.04 Sliding agent (WAX -1) 0.04 gelatin 0.55 In addition to the above composition, a coating aid Su-1, a dispersion aid Su-2, a viscosity modifier, a film hardener H-1, H-2, a stabilizer ST-1. , Antifoggant AF-1, weight average molecular weight: 1
Two types of AF-2 with 000 and weight average molecular weight of 1,100,000
And the preservative DI-1 was added. The amount of DI-1 added is 9.
It was 4 mg / m ² .

The structures of the compounds used in the above samples are shown below.

[0156]

[Chemical 1]

[0157]

[Chemical 2]

[0158]

[Chemical 3]

[0159]

[Chemical 4]

[0160]

[Chemical 5]

[0161]

[Chemical 6]

[0162]

[Chemical 7]

After exposing these samples to sensitometry with white light, they were respectively stored under the following two conditions A and B, and processed in the following processing steps to obtain sensitivity and RMS.
The granularity was evaluated. Immediately after the exposure for sensitometry with white light was applied, the same treatment was performed and evaluated.

(Conditions) A: 40 ° C., 20% RH for 3 days B: 23 ° C., 50% RH for 14 days [Processing step (38 ° C.)] Color development 3 minutes 15 seconds Bleach 6 minutes 30 seconds Washing with water 3 minutes 15 seconds Settling 6 minutes 30 seconds Water washing 3 minutes 15 seconds Stabilization 1 minute 30 seconds Drying The treatment liquid composition used in the treatment process is as follows.

[Color developer] 4-amino-3-methyl-N-ethyl-N- (β-hydroxyethyl) -aniline / sulfate 4.75 g anhydrous sodium sulfite 4.25 g hydroxylamine / 1/2 sulfate 2.0 g Anhydrous potassium carbonate 37.5 g Sodium bromide 1.3 g Nitrilotriacetic acid trisodium salt (monohydrate) 2.5 g Potassium hydroxide 1.0 g Water is added to make 1 liter, and the pH is adjusted to 10.0.

[Bleach] Ethylenediaminetetraacetic acid ammonium ammonium salt 100.0 g Ethylenediaminetetraacetic acid diammonium salt 10.0 g Ammonium bromide 150.0 g Glacial acetic acid 10.0 g Water was added to make 1 liter, and the pH was adjusted to 6.0 with ammonia water. To do.

[Fixer] Ammonium thiosulfate 175.0 g Anhydrous sodium sulfite 8.5 g Sodium metasulfite 2.3 g Water is added to make 1 liter, and pH is adjusted to 6.0 with acetic acid.

[Stabilizer] Formalin (37% aqueous solution) 1.5 ml Conidax (manufactured by Konica Corporation) 7.5 ml Water is added to make 1 liter.

The sensitivity (S) is the relative value of the reciprocal of the received light amount giving a density of fog +0.1, and is the relative value when the green sensitivity of the sample (No. 11) immediately after exposure is 100. Indicated.

The RMS granularity is 1000 times the fluctuation of the density value that occurs when the density of the minimum density +1.0 is scanned by a microdensitometer with an aperture scanning area of 250 μm ² , and the sample immediately after exposure (No. 11) The RMS value is shown as a relative value when the RMS value is 100.

In Table 4, Emulsion A, namely (Em-1) to (Em-10)
The evaluation results of the sensitivity and RMS granularity of the coated samples (No. 11) to (No. 20) using the are shown.

[0172]

[Table 4]

From Table 4, the silver halide photographic emulsion of the present invention
Samples (No. 1) using (Em-3) to (Em-7) and (Em-10)
3) to (No. 17) and (Em-20), when stored under the condition A, photographic performance equivalent to or better than that of the sample using the comparative emulsion was obtained in both sensitivity and RMS granularity. ing.
Further, even when stored under the condition B, the sample using the silver halide photographic emulsion of the present invention shows excellent photographic performance in both sensitivity and RMS granularity as compared with the sample using the comparative emulsion. .

Example 2 (Preparation of Comparative Silver Halide Emulsion (Em-11)) A comparative silver halide emulsion (Em-11) was prepared using the following 5 kinds of solutions.
Was prepared.

(Solution A-3) Ocein gelatin 69.0 g Distilled water 3321 ml HO (CH ₂ CH ₂ O) _m (CHCH ₃ CH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) 10 Weight% methanol solution 2.50 ml Seed emulsion (T-1) used in Example 1 71.8 g Finish to 3500 cc with distilled water (solution B-3) 3.5N silver nitrate aqueous solution 4650.0 ml (solution C-3) potassium bromide 2499.0 g Finish with distilled water to 6000 cc (Solution D-3) A fine grain emulsion comprising 3% by weight of gelatin and silver iodide grains (average grain size: 0.05 μm) is shown below. 2333.0 g To 5000 ml of a 6.0 wt% gelatin solution containing 0.06 mol of potassium iodide, 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 2000 ml of 7.06 mol of potassium iodide were added over 10 minutes.
The temperature during fine particle formation was controlled at 40 ° C. The finished weight is
It was 12.53 kg.

(Solution E-3) 1.75N Potassium Bromide Aqueous Solution Necessary amount Solution A-3 was added to a reaction vessel and stirred vigorously.
Solution B-3 to solution D-3 were added according to the combination shown in Table 5 by the simultaneous mixing method to grow a seed crystal to prepare a core / shell type silver halide emulsion.

Here, (1) solution B-3, solution C-3 and solution D-3 addition rates, (2) solution B-3 and solution C-3
The addition rate of each was changed in a function-like manner with respect to time as commensurate with the critical growth rate of silver halide grains, and in addition to the growing seed crystals, small grains were generated and polydispersion due to Ostwald ripening occurred. The addition rate was controlled so that it would not occur.

The temperature of the solution in the reaction vessel was controlled at 75 ° C. and the pAg was controlled at 8.8 over the entire area of crystal growth. pA
Solution E-3 was added as needed for g control.

Table 5 also shows the amount of silver added at that time and the silver iodide content of the silver halide phase during formation with respect to the addition time of the addition solution.

After grain growth, desalting treatment was performed according to the method described in Japanese Patent Application No. 4-59351, and a 20% by weight aqueous gelatin solution was added.
Add 1.19 L and disperse at 50 ° C for 30 minutes, then add pH at 40 ° C.
5.80 and pBr were adjusted to 3.55.

The silver halide grains contained in the obtained silver halide emulsion are monodisperse tabular silver halide grains having an average grain size of 1.65 μm (diameter in terms of projected area circle), an average aspect ratio of 3.5 and a grain size distribution of 16%. Met.

[0182]

[Table 5]

(Preparation of Comparative Emulsion (Em-12)) Comparative Emulsion (Em-12)
In the preparation of m-11), comparison was made in exactly the same manner except that pH was adjusted to 8.0 with 10% aqueous potassium hydroxide solution 97.72 minutes after the addition of Solution B-3 to Solution D-3 was started. An emulsion (Em-12) was prepared. The history of pH in the reaction vessel was as follows.

Time (minutes) from the start of addition of Solution B-3 to Solution D-3 97.72 175.94 198.41 211.09 220.45 pH 8.00 7.02 6.68 6.59 6.38 (Preparation of comparative emulsion (Em-13)) In the preparation of the comparative emulsion (Em-11), after grain growth and before desalting, the pH was adjusted to 8.5 at 75 ° C. with a 10% aqueous potassium hydroxide solution, ripened for 20 minutes, and then adjusted to pH with acetic acid. I set it to 5.8.

After grain growth, desalting treatment was performed according to the method described in Japanese Patent Application No. 4-59351, and a 20% by weight aqueous gelatin solution was added.
Add 1.19L and disperse for 15 minutes at 50 ℃, then 3.5N at 50 ℃
After adjusting the pBr to 1.5 with an aqueous potassium bromide solution, the following solution H-2 was added to the stirring silver halide emulsion in 30 seconds, and 10 minutes thereafter, the following solution I-2 was added in 30 seconds. ,That
After 10 minutes, a comparative emulsion (Em-13) was prepared in exactly the same manner except that the following solution J-2 was added for 30 seconds, the mixture was stirred for 20 minutes, and then pH was adjusted to 5.80 and pBr to 3.55 at 40 ° C. did.

(Solution H-2) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.212 mol (Solution I-2) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.212 mol (solution J-2) A fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is prepared as follows. 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 2000 ml of 7.06 mol of potassium bromide were added to 5000 ml of a 6.0% by weight gelatin solution containing 0.212 mol and 0.06 mol of potassium bromide over 10 minutes.
The temperature during fine particle formation was controlled at 30 ° C. During particle formation
The pH was controlled to 3.0 using nitric acid, and after forming fine particles, the pH was adjusted to 6.0 using an aqueous sodium carbonate solution.

(Preparation of Emulsion (Em-14) of the Present Invention) In the preparation of the comparative emulsion (Em-12), after the grain growth, Japanese Patent Application No. 4-5
After desalting according to the method described in No. 9351, 1.19 L of 20% by weight gelatin aqueous solution was added and dispersed at 50 ° C. for 15 minutes,
The pBr was adjusted to 1.5 with a 3.5N potassium bromide aqueous solution at 50 ° C., and the following solution H-3 was added to the stirred silver halide emulsion.
Was added in 30 seconds, 10 minutes later, the following solution I-3 was added in 30 seconds, 10 minutes later, the following solution J-3 was added in 30 seconds, and the mixture was stirred for 20 minutes and then at 40 ° C. 5.80, pBr
The emulsion of the present invention was prepared in the same manner except that it was adjusted to 3.55.
(Em-14) was prepared.

(Solution H-3) A fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is prepared as follows. 0.212 mol (solution I-3) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.212 mol (solution J-3) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 2000 ml of 7.06 mol of potassium bromide were added to 5000 ml of a 6.0% by weight gelatin solution containing 0.212 mol and 0.06 mol of potassium bromide over 10 minutes.
The temperature during fine particle formation was controlled at 30 ° C. During particle formation
The pH was controlled to 3.0 using nitric acid, and after forming fine particles, the pH was adjusted to 6.0 using an aqueous sodium carbonate solution.

(Preparation of Emulsion (Em-15) of the Present Invention) Solution B-3 to Solution D-3 in the preparation of comparative emulsion (Em-11)
97.72 minutes after the addition of the above was started, the pH was adjusted to 6.8 using a 10% aqueous potassium hydroxide solution. PH in the reaction vessel
The history of was:

Time (min) from the start of addition of Solution B-3 to Solution D-3 97.72 175.94 198.41 211.09 220.45 pH 6.80 6.52 6.42 6.35 6.19 in the reaction vessel Further, after particle growth, Japanese Patent Application No. Desalted according to the method described in 59351, 20% by weight gelatin aqueous solution 1.19
After adding L and dispersing at 50 ° C for 15 minutes, pBr was adjusted to 1.5 with 3.5N potassium bromide aqueous solution at 50 ° C, and the following solution H-4 was added to the stirring silver halide emulsion for 30 seconds. Add
10 minutes later, the following solution I-4 was added in 30 seconds, 10 minutes later, the following solution J-4 was added in 30 seconds, and after stirring for 20 minutes, pH was adjusted to 5.80 and pBr to 3.55 at 40 ° C. The emulsion of the present invention (Em-15) was prepared in exactly the same manner except that the above was carried out.

(Solution H-4) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.212 mol (solution I-4) A method for preparing a fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is shown below. 0.212 mol (solution J-4) A fine grain emulsion comprising 3% by weight of gelatin and silver bromide grains (average grain size 0.04 μm) is prepared as follows. 2000 ml of an aqueous solution containing 7.06 mol of silver nitrate and 2000 ml of 7.06 mol of potassium bromide were added to 5000 ml of a 6.0% by weight gelatin solution containing 0.212 mol and 0.06 mol of potassium bromide over 10 minutes.
The temperature during fine particle formation was controlled at 30 ° C. During particle formation
The pH was controlled to 3.0 using nitric acid, and after forming fine particles, the pH was adjusted to 6.0 using an aqueous sodium carbonate solution.

Table 6 shows the characteristics of the emulsions (Em-11) to (Em-15).

[0193]

[Table 6]

Emulsions (Em-11) to (Em-15) were optimally chemically sensitized. Each of these emulsions was used in Example 1
(Emulsion A) was used in the same manner to prepare multilayer color photographic light-sensitive material samples Nos. 21 to 25.

The multilayer color photographic light-sensitive material samples Nos. 21 to 25 thus prepared were evaluated in the same manner as in Example 1.

The evaluation results are shown in Table 7.

[0197]

[Table 7]

From Table 7, the silver halide photographic emulsion of the present invention
Samples (No. 24) and (No. 2) using (Em-14) and (Em-15)
In the case of 5), when stored under the condition A, photographic performance equivalent to or higher than that of the sample using the comparative emulsion was obtained in both sensitivity and RMS granularity. Furthermore, the more severe condition B
When stored at 1, the sample using the silver halide photographic emulsion of the present invention has a higher sensitivity and RMS than the sample using the comparative emulsion.
Excellent photographic performance is shown at any of the granularities.

[0199]

INDUSTRIAL APPLICABILITY According to the present invention, a silver halide photographic emulsion which gives a silver halide photographic light-sensitive material excellent in sensitivity, graininess, and particularly sensitivity and graininess after long-term storage after exposure and a halogen using the same. A silver halide photographic light-sensitive material can be provided.

Claims (3)

[Claims] 1. A silver halide photographic emulsion containing silver halide grains and a dispersion medium, wherein the silver halide grains contained in the silver halide photographic emulsion have an average silver iodide content of from 2 mol% to 30 mol%. And the average silver iodide content of the outermost layer of the silver halide grains is I ₁ (mol%), and the average silver iodide content of the silver halide grains is I ₂ (mol%). A silver halide photographic emulsion characterized by satisfying I ₁ <I ₂ and reduction-sensitized inside of the silver halide grains. 2. A protective colloid aqueous solution in which the silver halide grains are grown without using an ammonium compound, and the reduction sensitization is carried out during the growth of the silver halide grains. The silver halide photographic emulsion according to claim 1, wherein the pH is adjusted to 7.0 or more. 3. A silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support,
A silver halide photographic light-sensitive material, characterized in that at least one of the silver halide emulsion layers contains the silver halide photographic emulsion according to claim 1 or 2.