JPH0588296A - Black-and-white silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To provide the black-and-white silver halide photographic sensitive material high in sensitivity and not causing uneven blackened density at the time of tank development processing. CONSTITUTION:This black-and-white photographic silver halide sensitive material comprises >=2 silver halide emulsion layers and the outermost emulsion layer contains silver halide grains having an average grain diameter of <=0.3mum and a silver iodide content of >=0.3mol% on the surface of the grains, and at least one of the other emulsion layers contains silver halide grains having an average grain diameter of >=4mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black and white silver halide photographic material.

[0002]

2. Description of the Related Art Most black-and-white silver halide sensitizers are composed of a halogen composition mainly composed of silver bromide, but very often grains containing a small amount of silver iodide are used for various purposes. For example, the incorporation of silver iodide for the purpose of increasing the sensitivity has been a commonly used technique from old days. At this time, it is usual that a large amount of silver iodide is present on the grain surface.

However, it is often experienced that when a large amount of silver iodide is introduced into the grain, the silver iodide oozes to the surface to some extent. In some cases, it is possible to obtain better performance by intentionally allowing a large amount of silver iodide to be present on the surface. For example, there is an example in which photographic performance is improved by the means disclosed in JP-A-1-152446. Further, in the industrial X-ray field, there is unevenness in sensitization called "sensitizing screen stain" that occurs when it comes into contact with a lead foil intensifying screen. There is a knowledge that is good. In such a case, better performance may be obtained when a large amount of silver iodide is present on the grain surface.
In some cases, the size of the adverse effect is compared with these advantages, and the silver iodide may be prepared so as to exist on the grain surface to some extent.

However, in general, the amount of silver iodide on the grain surface is often set to a low level, and this is because of many adverse effects. One of them is as follows. .. It has been found that the density unevenness is likely to occur when the photosensitive material is subjected to the development processing, and is particularly remarkable when the development is carried out by the manual stirring such as the tank processing and the plate development. It was found that this unevenness in density becomes more remarkable when a large amount of silver iodide is present on the surface of the grain, and is not a problem when silver iodide is present only inside the grain.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light-sensitive material which uses grains having silver iodide present on the grain surface and maintains the merit thereof without causing uneven density during tank processing. is there.

[0006]

The above object can be achieved by the following silver halide photographic light-sensitive material. In a black-and-white silver halide light-sensitive material in which silver halide grains are dispersed in a binder, there are two or more light-sensitive emulsion layers of the silver halide light-sensitive material. Of these emulsion layers, the layer closest to the surface layer (most An emulsion in which the average grain size of the silver halide grains in the surface emulsion layer) is 0.3 μm or less, the silver iodide content on the grain surface is 0.3 mol% or more, and the outermost emulsion layer is not present. At least one of the layers is a silver halide light-sensitive material characterized in that the average grain size of silver halide grains in the emulsion layer is 0.4 μm or more.

As the silver halide of the photosensitive silver halide emulsion used in the present invention, silver chlorobromide, silver bromide, silver iodobromide and silver chloroiodobromide can be used. Here, the content of silver iodide is preferably 30 mol% or less, particularly preferably 10 mol% or less. The distribution of iodine in the silver iodobromide grains may be uniform or may be different between the inside and the surface. However, the silver halide grains in the outermost emulsion have 0.3 mol% or more of silver iodide on the grain surface. As a method for allowing silver iodide to be present on the surface, a method of adding iodide ion as a halogen during grain formation may be used, or an iodide ion may be added after the grain formation, in a washing step, a post-ripening step, or before coating. The objective can be achieved by any of the methods.
The content of silver iodide present on the grain surface can be measured by the ESCA method or the like which is well known in the art.

The silver halide grains in the emulsion may have a regular crystal form such as a cube, an octahedron, a tetrahedron and a rhombohedron, and may also have a spherical shape, a plate shape, a potato shape or the like. It may consist of a mixture of grains of different crystal forms, which may have an irregular crystal form or a composite form of these crystal forms. Further, tabular grains having a grain size of 5 times or more the grain thickness are preferably used in the present invention (for details, RESEA).
RCH DISCROSURE 225 Volume Item 225
34P. 20-P. 58, January issue, 1983, and JP-A-58-127921 and 58-113926).

The average grain size of the silver halide grains is defined as the grain size, with the diameter of a sphere having the same volume as that of the grain, and the average value is defined as the average grain size. The average grain size of the outermost emulsion layer is 0.3 μm or less, preferably 0.3 μm to 0.05 μm, and the grains of the other emulsion layers are 0.1 μm to 2.0 μm. Preferably, at least one of the emulsion layers has an average grain size of 0.4 μm or more.

In the present invention, the number of photosensitive emulsion layers must be two or more. Of these, the thickness of the outermost emulsion layer is preferably 0.1 g / m ² or more in terms of the amount of coated silver, and if it is less than this, the object of the present invention cannot be achieved. The thickness of the outermost emulsion layer is more preferably 0.3 to 10 g / m ^{2 in} terms of coating silver amount,
It is more preferably 0.5 to 5 g / m ² .

In the present invention, the photosensitive silver halide emulsion may be a mixture of two or more kinds of silver halide emulsions. The emulsions to be mixed may differ in grain size, halogen composition, sensitivity, etc. The light-sensitive emulsion may be mixed with a substantially non-light-sensitive emulsion (which may or may not be fogged on the surface or inside), or it may be divided into separate layers (details). Is US Patent 2,996,38
2, No. 3,397,987, etc.). For example, the same layer as a light-sensitive silver halide emulsion comprising a spherical or potato-shaped light-sensitive emulsion and tabular grains having a grain size of 5 times or more the grain thickness, or JP-A-58-12.
It may be used in different layers as described in Japanese Patent No. 7921. When used in different layers, the light-sensitive silver halide emulsion consisting of tabular grains may be on the side closer to the support or conversely on the far side.

The photographic emulsion used in the present invention is P. Glafki.
des by Chimie et Physique Photographique (Paul Mo
ntel, 1967), GF Duffin, Photograp
hicEmulsion Chemistry (The Focal Press, 196
6 years), VL Zelikman et al. Makig and Coting Ph
otographic Emulsion (The Focal Press, 1964
Year), JP-A-58-127921 and 58-1139.
It can be adjusted using the method described in Japanese Patent Publication No. 26, etc. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and as a method of reacting a soluble silver salt and a soluble halogen salt, any of a one-sided mixing method, a simultaneous mixing method and a combination thereof may be used. ..

It is also possible to use a method of forming silver halide grains in the presence of excess silver ions (so-called reverse mixing method). As one type of the simultaneous mixing method, a method of keeping pAg constant in the liquid phase in which silver halide is formed, that is, a so-called controlled double jet method can be used. According to this method, a silver halide emulsion composed of silver halide grains having a regular crystal form and a substantially uniform grain size can be obtained.

Even if the crystal structure of the silver halide grains is uniform even in the inside, it has a layered structure in which the inside and the outside are different, British Patent 635,841 and US Pat. No. 3,622,318. It may be a so-called conversion type as described in No. Further, silver halides having different compositions may be joined by epitaxial joining, or may be joined with a compound other than silver rhodanide and silver oxide, for example. Either the surface latent image type or the internal latent image type may be used. In the process of silver halide grain formation or physical ripening during the production of silver halide, cadmium salt, zinc salt, lead salt, thallium salt, iridium salt or its complex salt, rhodium salt or its complex salt,
Iron salts or iron complex salts may coexist.

During grain formation, a so-called silver halide solvent such as ammonia, thioether compound, thiazolidine-2-thione, tetra-substituted thiourea, rhodan potassium, rhodan ammon and amine compound may be present to control grain growth. The silver halide emulsion used in the present invention may or may not be chemically sensitized. Chemical sensitization methods include sulfur sensitization, reduction sensitization,
Known methods such as gold sensitization can be used,
Used alone or in combination.

Among the noble metal sensitizing methods, the gold sensitizing method is a typical one, and a gold compound, mainly a gold complex salt is used. Noble metals other than gold, for example, platinum, palladium, iridium and other complex salts may be contained. A specific example is US Patent 2,
No. 448,06, British Patent No. 618,061 and the like. As the sulfur sensitizer, various sulfur compounds such as thiosulfates, thioureas, thiazoles, and rhodanines can be used in addition to the sulfur compounds contained in gelatin. As the reduction sensitizer, a primary tin salt, an amine, formamidinesulfinic acid, a silane compound or the like can be used. Further selenium compounds,
Sensitization with tellurium compounds is also preferably used.

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 {eg benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, nitroindazoles, benzotriazoles, aminotriazoles, etc.); mercapto compounds {eg mercapto Thiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles,
Mercaptotetrazoles (especially 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines, mercaptotriazines, etc .; thioketo compounds such as oxadrinethione; azaindenes {eg triazaindenes, tetraazaindenes (especially 4-hydroxy-substituted (1,3,3a, 7) tetraazaindenes), pentaazaindenes, etc .; benzenethiosulfonic acid, benzenesulfinic acid, benzenesulfonic acid amide and the like antifoggants or stabilizers Many compounds can be added, known as.

Specifically, RESERCH DISCLO
SER Item 17643 VI (December 1978 issue, P. 24 to P. 25) or cited therein. In particular, JP-A-60-76743 and 6
Nitron and its derivatives described in JP-A-0-87322, mercapto compounds described in JP-A-60-80839, heterocyclic compounds described in JP-A-57-164735, and complex salts of heterocyclic compounds with silver. (Eg 1
-Phenyl-5-mercaptotetrazole silver) and the like can be preferably used.

The photosensitive silver halide emulsion of the present invention may be spectrally sensitized by a sensitizing dye to blue light, green light, red light or infrared light having a relatively long wavelength. As a sensitizing dye,
Cyanine dye, merocyanine dye, complex cyanine dye, complex merocyanine dye, holoholer cyanine dye, styryl dye, hemicyanine dye,
Oxonol dyes, hemioxonol dyes and the like can be used. Useful sensitizing dyes used in the present invention are, for example, the RESERCH DISCROSURE Item.
17643 IV-A (P.23, December 1978),
Item 18431 X (P.4, August 1979)
37) or the literature cited.

The sensitizing dye can be used by being present in any step of the process for producing a photographic emulsion, or can be present in any stage after production until immediately before coating. Examples of the former include a silver halide grain forming step, a physical ripening step and a chemical ripening step.

In the photographic emulsion layer or other hydrophilic colloid layer of the light-sensitive material produced by using the present invention, coating aids, antistatic agents, slipperiness improvement, emulsion dispersion, adhesion prevention and photographic property improvement (for example, development acceleration) , Hardening, and sensitization), various surfactants may be included. For example, saponin (steroidal), alkylene oxide derivative (eg polyethylene glycol, polyethylene glycol /
Nonionic surfactants such as polypropylene glycol condensates, polyethylene glycol alkyl ethers or polyethylene glycol alkyl aryl ethers, silicone polyethylene oxide adducts), sugar alkyl esters; alkyl sulfonates, alkyl benzene sulfonates , Alkylnaphthalene sulfonate, alkyl sulfates, N-acyl-N
Anionic surfactants such as alkyl taurines, sulfosuccinates, sulfoalkyl polyoxyethylene alkyl phenyl ethers; amphoteric surfactants such as alkyl betaines, alkyl sulfobetaines;
Cationic surfactants such as aliphatic or aromatic quaternary ammonium salts, pyridinium salts and imidazolium salts can be used.

Of these, saponin, Na salt of dodecylbenzene sulfonic acid, Na salt of di-2-ethylhexyl α-sulfosuccinic acid, Na salt of p-octylphenoxyethoxyethane sulfonic acid, Na salt of dodecyl sulfate, Na salt of triisopropylnaphthalene sulfonic acid. , Anion such as N-methyl-oleoyl taurine Na salt, dodecyltrimethylammonium chloride, N-oleoyl-N ′,
Cations such as N ′, N′-trimethylammoniodiaminopropane bromide and dodecylpyridinium chloride, betaines such as N-dodecyl-N, N-dimethylcarboxybetaine and N-oleyl-N, N-dimethylsulfobutylbetaine, and polyynes. (Average degree of polymerization n = 10) oxyethylene cetyl ether, poly (n = 25) oxyethylene p-nonylphenol ether, bis (1-poly (n = 15) oxyethylene-oxy-2,4-di-t
Nonionics such as -pentylphenyl) ethane can be particularly preferably used.

As the antistatic agent, perfluorooctanesulfonic acid K salt, N-propyl-N-perfluorooctanesulfonylglycine Na salt, N-propyl-N-perfluorooctanesulfonylaminoethyloxypoly (n = 3) oxy Ethylene butanesulfonic acid Na salt, N
-Perfluorooctanesulfonyl-N ', N', N '
-Trimethylammoniodiaminopropane chloride,
N-perfluorodecanoylaminopropyl N ', N'
Fluorine-containing surfactants such as dimethyl-N'-carboxybetaine, JP-A-60-80848 and 61-112.
144, Japanese Patent Application Nos. 61-13398 and 61-160.
The nonionic surfactants described in 50, alkali metal nitrates, conductive tin oxide, zinc oxide, vanadium pentoxide, or composite oxides obtained by doping these with antimony or the like can be preferably used.

In the present invention, as a matting agent, a homopolymer of polymethylmethacrylate or a polymer of methylmethacrylate and methacrylic acid, organic compounds such as starch, and fine particles of inorganic compounds such as silica and titanium dioxide can be used. .. The particle size is 1.0-1
It is preferably 0 μm, particularly preferably 2 to 5 μm. Silicone compounds described in U.S. Pat. Nos. 3,489,576 and 4,047,958 are used as slipping agents in the surface layer of the photographic light-sensitive material of the present invention, and colloidal silica described in JP-B-56-23139. Besides, paraffin wax, higher fatty acid ester, den powder derivative and the like can be used.

Polyols such as trimethylolpropane, pentanediol, butanediol, ethylene glycol and glycerin can be used as plasticizers in the hydrophilic colloid layer of the photographic light-sensitive material of the present invention. Further, the hydrophilic colloid layer of the photographic light-sensitive material of the present invention preferably contains a polymer latex for the purpose of improving pressure resistance. As the polymer, a homopolymer of an alkyl ester of acrylic acid, a copolymer with acrylic acid, a styrene-butadiene copolymer, or a polymer or copolymer comprising a monomer having an active methylene group can be preferably used.

The photographic emulsion and the non-photosensitive hydrophilic colloid of the present invention may contain an inorganic or organic hardener. For example, chromium salts, aldehydes (formaldehyde, glitalaldehyde, etc.), N-methylol compounds (dimethylolurea, etc.), dioxane derivatives (2,3-dihydroxydioxane, etc.), active vinyl compounds (1,
3,5-triacryloyl-hexahydro-s-triazine, bis (vinylsulfonyl) methyl ether, N,
N'-methylenebis- [β- (vinylsulfonyl) propionamide] etc.), active halogen compounds (2,4-
Dichloro-6-hydroxy-s-triazine etc.), mucohalogen acids (mucochloric acid etc.), N-carbamoylpyridinium salts (1-morpholinocarbonyl-3-
(Pyridinio) methanesulfonate, etc.), haloamidinium salts (1- (1-chloro-1-pyridinomethylene))
Pyrrolidinium, 2-naphthalene sulfonate, etc.) can be used alone or in combination. Among them, JP-A Nos. 53-41220, 53-57257, and 59-
The active vinyl compounds described in 162546 and 60-80846 and the active halides described in US Pat. No. 3,325,287 are preferred.

When the light-sensitive material of the present invention is used as an X-ray sensitive material, the hydrophilic colloid layer is preferably hardened by these hardeners so that the swelling rate in water is 280% or less. .. As the binder or protective colloid that can be used in the emulsion layer or intermediate layer of the light-sensitive material of the present invention, it is advantageous to use gelatin, but other hydrophilic colloids can also be used.

For example, dextran, polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-
A wide variety of synthetic hydrophilic polymeric substances such as vinylpyrrolidone, polyacrylic acid, polyacrylamide, polyvinyl imidazole, single or copolymers can be used. As gelatin, lime-processed gelatin, acid-processed gelatin or enzyme-processed gelatin may be used, and a hydrolyzate of gelatin may also be used. Among these, it is preferable to use dextran and polyacrylamide together with gelatin.

The silver halide photographic light-sensitive material of the present invention may have a non-light-sensitive layer such as a surface protective layer, an intermediate layer and an antihalation layer in addition to the light-sensitive silver halide emulsion layer. The number of silver halide emulsion layers may be any as long as it is two or more.
The sensitivity, gradation and the like of the silver halide emulsion layers of two or more layers may be different. Further, it may have a silver halide emulsion layer or a non-photosensitive layer on both sides of the support.

A cellulose triacetate film is preferable as a support for a general light-sensitive material, and either of them may be colored for antihalation and may be uncolored. X
A polyethylene terephthalate film or a cellulose triacetate film is preferable as the support for the radiographic light-sensitive material, and particularly preferably colored blue.

The support is preferably subjected to a corona discharge treatment, a claw discharge treatment or an ultraviolet irradiation treatment for improving the adhesion to the hydrophilic colloid layer, or a styrene butadiene latex or a vinylidene chloride latex. May be provided with a subbing layer, and a gelatin layer may be further provided thereon.
An undercoat layer using an organic solvent containing a polyester swelling agent and gelatin may be provided. By applying a surface treatment to these undercoat layers, the adhesion with the hydrophilic colloid layer can be further improved.

The present invention can be used for any photographic light-sensitive material which is subjected to ordinary development processing.
For example, it is used for X-ray photographic light-sensitive materials, lith-type photographic light-sensitive materials, black-and-white negative photographic light-sensitive materials, black-and-white paper light-sensitive materials. Here, when used as a photographic light-sensitive material for X-rays, RESEARCH DISCROSURE It
em18431 (P.433-P.44, August 1979)
1) Technology relating to stabilizers, antifoggants and anti-knick agents (P.433 to P.436), technology relating to protective layer (P.436, section IV), crossover control technology (P.436) It is preferable to use (V).

In order to obtain an X-ray photographic image, the exposure may be carried out by using a usual method. That is, it is a method in which a light-sensitive material having a light-sensitive layer on both sides is sandwiched between two fluorescent intensifying screens or lead foil intensifying screens and exposed by X-rays. Alternatively, in the case of a photosensitive material having a photosensitive layer on one side, a method of irradiating a fluorescent intensifying screen with X-rays and recording the emitted light on the photosensitive material is used. Of course, X-ray irradiation may be performed by bringing the light-sensitive material into contact with the fluorescent intensifying screen. Here, as the phosphor, a blue-emitting calcium tungstate, a barium sulfate or other phosphor, and a green-emitting rare earth phosphor are used. In addition, after accumulating X-ray exposed materials in a phosphor, various light sources including infrared light such as cathode ray tube flying spot, light emitting diode, laser light (for example, gas laser, YAG laser, dye laser, semiconductor laser, etc.) It can also be exposed. When used for purposes other than X-ray photography, ordinary exposure methods can be used. The sensitive material of the present invention is
You may expose using a light wavelength conversion element.

For the photographic processing of the light-sensitive material of the present invention, for example, Research Disclosure (RESEARCH D
ISCLOSURE) 176 pages 28-30 (RD-
Any of known methods and known processing solutions as described in 17643) can be applied. The treatment temperature is usually selected between 18 ° C and 50 ° C, but 18 ° C
Lower temperatures or temperatures above 50 ° C. may be used.

The developer used for photographic processing may contain known developing agents. Examples of developing agents include dihydroxybenzenes (for example, hydroquinone) and 3-pyrazolidones (for example, 1-phenyl-3).
-Pyrazolidone), aminophenols (eg N-
(Methyl-p-aminophenol) and the like can be used alone or in combination. For the photographic processing of the light-sensitive material of the present invention, it is also possible to perform processing with a developing solution containing imidazoles as a silver halide solvent described in JP-A-57-78535. Further, it can be processed with a developing solution containing a silver halide solvent described in JP-A-58-37643 and an additive such as indazole or triazole. The developer generally contains other known preservatives, alkali agents, pH buffers, antifoggants and the like, and further contains a solubilizer, a color tone agent, a development accelerator, a surfactant, if necessary.
A defoaming agent, a water softening agent, a film hardening agent (eg, glutaraldehyde), a viscosity imparting agent and the like may be included.

As the fixing liquid, those having a generally used composition can be used. Thiosulfate as a fixing agent,
In addition to thiocyanate, an organic sulfur compound known to have an effect as a fixing agent can be used. The fixing solution may contain a water-soluble aluminum salt as a hardening agent.

[0037]

The present invention will be further described with reference to the following examples. Example 1 (Emulsion-a) Ammonia was used as a silver halide solvent, and a side length of 0.3 was measured by a control double jet method.
A 2μ cubic silver bromide grain was prepared. Further, grain formation was continued in the same manner as this time to form shell grains containing 1.0 mol% of silver iodide, and finally 0.40 µ cubic silver iodobromide grains were prepared. This emulsion was desalted in the usual manner and then β-oxyethyl phenyl ether, 1-
Phenyl-5-mercaptotetrazole was added, and chemical sensitization using gold and sulfur sensitization was further performed to give 4-hydroxy-6-methyl-1,3,3 as a stabilizer.
a, 7-Tetrazaindene was added.

(Emulsion-b, c, d) The silver iodide contents in forming the second-stage grains are 0.6, 0.3 and 0, respectively.
Emulsion-except that the halogen composition was changed to be mol%
Emulsions were prepared in the same manner as in a and designated as emulsions-b, c and d, respectively. (Emulsion-e, f) Emulsion-e and f were adjusted in the same manner as emulsion-a except that the addition amount of ammonia was changed so that the final grain sizes were 0.2 μ and 0.5 μ, respectively. ..

(Samples 1 to 8) Emulsions a to f prepared as described above were further added with sodium 3- (5-mercaptotetrazole) -benzenesulfonate, polyacrylamide, colloidal silica and 2,4-dichloro-6. -Hydroxy-s-triazine was added and coating was performed as shown in Table 1. At this time, gelatin, matting agent, anionic surfactant, polyethylene oxide-based nonionic surfactant, fluorine-containing compound, organopolysiloxane, composite latex (VONCOAT manufactured by Dainippon Ink and Chemicals, Inc.)
DV-759) added surface protection layer at the same time,
This was coated on both sides of a polyethylene terephthalate support. At this time, the total amount of silver coated was 7 g / m ^2, and when two layers were formed, 3.5 g / m ^{2 was} coated on each of the upper and lower layers.

[0040]

[Table 1]

For these samples, the following method was used.
Each item was evaluated. <X-ray sensitivity> Place the sample in a cassette sandwiched with lead foil intensifying screens, and irradiate for 1 second, 1.6 seconds, 2.5 seconds ...
The X-ray irradiation was performed so as to be (10 ^0.2 times longer). This sample was developed according to the procedure shown in the following table, the optical density of the obtained sample was measured, and these density points were connected smoothly to obtain the relationship of log (X-ray irradiation time) -optical density. From now on, the optical density will be Fog +2.0
The X-ray irradiation time at the point was calculated, and the reciprocal was calculated from this value using the reciprocal thereof as an index of sensitivity.

[0042]

[Table 2]

<Staining on intensifying screen> After the X-ray irradiation so that the optical density was about 1.5, the sample was sandwiched with a lead foil intensifying screen when the following treatment was performed, and Clip the four corners from the top. Repeat the bending and unfolding 10 times with these 3 sheets stacked. After that, the clip is removed, the sample is taken out, and the development process is performed in the following procedure.

[0044]

[Table 3]

In the sample treated by such a procedure, a blackened portion appears in the portion sandwiched by the clips, and the degree of this blackening was evaluated by a sensory evaluation in five levels. It shows the case where 5 points have almost no blackening and 1 point has a very strong blackening.

<Tank processing unevenness> Sample is 36 cm x 43 cm
Then, after the X-ray irradiation so that the optical density becomes 1.5 in the development processing described below, it is fixed on a hanger for tank processing usually used in the art. The following developing process was performed using a tank processor in which 38 liters of developing solution was put in the developing solution tank. Among them, during the developing step, the sample was put in the liquid, and the sample was moved up and down by about 5 cm for 5 seconds and stirred, and this was repeated every 1 minute for 5 seconds.

[0047]

[Table 4]

The thus obtained sample has an optical density of about 1.5, but the optical density differs depending on the part depending on the sample, and the center has a high density and the peripheral part has a low density. Uniform unevenness occurs. The unevenness was sensory-evaluated, and a score of 5 points (no unevenness) to 1 point (particularly strong unevenness) was given. Sample No. 1
Table 2 shows the scores of these items for ~ 8.

[0049]

[Table 5]

As can be seen from this table, when the silver iodide content on the grain surface is reduced, the tank processing unevenness is improved, but the stain on the intensifying screen is deteriorated. Further, if the particle size is reduced, stains on the intensifying screen and unevenness in tank processing are improved, but the photographic sensitivity is lowered, which is not preferable. On the contrary, when the particle size is large, the sensitivity is preferable, but the tank processing unevenness is further deteriorated. As disclosed in the present invention, Sample 8 in which a fine grain emulsion was coated on the surface protective layer side with a large surface silver iodide content and a large-sized grain emulsion was coated on the support side was preferable in all of these items. It turns out that the result is obtained. Further, if the order of coating is reversed and large-sized particles are used on the surface side, processing unevenness and stains on the intensifying screen are deteriorated, which is not preferable. Therefore, it is understood that only the combination disclosed in the present invention can obtain favorable results for all of these evaluation items.

Example 2 Samples 9 to 13 having the combinations shown in Table 3 were prepared according to the same emulsion weighing as in Example 1.

[0052]

[Table 6]

For these samples 9 to 13, the same evaluation as above was 1, and the obtained results are shown in Table 4.

[0054]

[Table 7]

From this, the surface emulsion layer was 0.2 g / m ²
If it is applied, the effect of improving unevenness in tank processing will appear,
It can be seen that as the thickness increases, the quality improves, and when the thickness is 1.0 g / m ² or more, the quality improves sufficiently. Further, when the surface emulsion layer as disclosed in the present invention is coated, there is a surprising effect that even if the silver iodide content of the grains of the emulsion layer on the support side is set to zero, the stain on the intensifying screen does not deteriorate. I also understand.

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[Procedure amendment]

[Submission date] August 12, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Most black-and-white silver halide sensitizers are composed of a halogen composition mainly composed of silver bromide, but very often grains containing a small amount of silver iodide are used for various purposes. For example, the incorporation of silver iodide for the purpose of increasing the sensitivity has been a commonly used technique from old days. At this time, it is usually the case that a large amount of silver iodide is present inside the grain.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Item name to be corrected] 0040

[Correction method] Change

[Correction content]

[0040]

[Table 1]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

[0052]

[Table 6]

Claims (1)

[Claims] 1. A black and white silver halide light-sensitive material comprising silver halide grains dispersed in a binder, wherein the silver halide light-sensitive material has two or more photosensitive emulsion layers. The average grain size of the silver halide grains in the layer closest to the layer (outermost emulsion layer) is 0.3 μm or less, and the silver iodide content on the surface of the silver halide grains is 0.3 mol%.
And at least one of the emulsion layers other than the outermost emulsion layer has an average grain size of silver halide grains in the emulsion layer of 0.4 μm or more. Photosensitive material.