JPS6243640A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To increase the sensitivity in spite of a low silver content as well as to improve the gradient and graininess by using two or more kinds of surface latent image type silver halide (AgX) emulsions having different average particle sizes in combination with an AgX emulsion having internal fogging nuclei. CONSTITUTION:A surface latent image type AgX emulsion and an AgX emulsion having internal fogging nuclei are combinedly used, and the surface latent image type AgX emulsion is composed of two or more kinds of surface latent image type AgX emulsions having different average particle sizes. The silver iodide content in the surface latent image type AgX emulsion having the largest average particle size is preferably made lower than that in other surface latent image type AgX emulsion. At least one of the two or more kinds of surface latent image type AgX emulsions is preferably a monodisperse emulsion. An AgX photographic material having high sensitivity in spite of a low silver content as well as superior gradient and fine graininess can be obtd. by combinedly using the surface latent image type AgX emulsions having said structure and the AgX emulsion having internal fogging nuclei.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a highly sensitive silver halide photographic glare glass, particularly a highly sensitive silver halide photographic glass with sharp gradations, excellent graininess, and a low silver content. This invention relates to silver halide photographic materials.

[Conventional technology]

Increasing the sensitivity of the film is important in order to reduce the amount of silver used. In addition, in X-ray films, it is also important for reducing exposure dose.

Silver halide photographic materials have thicker silver halide emulsion grains (thus increasing sensitivity.
It is undesirable because the graininess and covering power are reduced, the black density after development is reduced, and T (gamma, the slope of the straight part of the characteristic curve) is reduced (JP-A-59-148051).
Publication No.). In order to improve these problems, a large amount of silver is required per unit area of the film, which is undesirable because it increases the product cost.

When silver halide grains having a small grain size and having fog nuclei inside that have virtually no surface sensitivity are used in combination with silver halide grains containing silver iodide and having a large grain size and a surface latent image type,
Silver halide grains with fog nuclei inside which have a large covering power are infected and developed as the surface latent image type emulsion is developed, so that a photosensitive material with high sensitivity and a large covering power can be obtained. No. 2068, U.S. Patent No. 3,178,282), but this technology has poor graininess and cannot control the infection development effect in a developer containing a large amount of sulfite, which is a developer preservative. Therefore, it is difficult to adjust the gradation of the sensimetry curve.

[Purpose of the invention]

An object of the present invention is to solve the problems of the prior art as described above, and to provide a silver halide photographic material with uniform gradation, excellent graininess, and high sensitivity despite its low silver content. .

[Structure and operation of the invention] The above object is to use a surface latent image type silver halide emulsion and a silver halide emulsion having internal fog nuclei together, and to use surface latent image type silver halide emulsions having different average grain sizes. This is achieved by containing at least two types.

In this case, in a surface latent image type silver halide emulsion containing at least two types of emulsions with different average grain sizes, the silver iodide content of the emulsion with the largest average grain size is higher than that of the other surface latent image type silver halide emulsions. It is preferable that the silver iodide content is lower than the silver iodide content of the silver emulsion. Further, the surface latent image type silver halide emulsion containing at least two types of emulsions having different average grain sizes is preferably one in which at least one type is a monodisperse emulsion.

In the surface latent image type silver halide emulsion, the difference in silver iodide content is preferably in the range of 0.3 to 8 mol %. In addition,
If the amount is less than 0.2 mol, the effect of the present invention is small.

The materials used in the present invention will be explained below. A silver halide emulsion having internal fog nuclei has a double structure of a core part and a shell part. The above-mentioned silver halide emulsion can be obtained by coating the core with fog nuclei, growing grains, and covering the fog nuclei with the shell. At this time, if the core portion contains silver chloride (AgC1), the silvery steel becomes better.

Further, the silver halide present in the core portion is silver chlorobromide (AgBrCj) or silver chloride (AgCj).

Silver bromide (AgBr), iI iodobromide (AgBrl).

Any silver chloroiodobromide (AgBrC421) may be used.

Fog nuclei are formed on the surface of the core portion by irradiation with light, X-rays, etc., a method using a reducing agent or a gold compound, and a method of aging at low pA and g and high pH.

The thickness of the shell portion is at least 0.01 μm, and the silver halide present in the shell portion is AgBr1°AgBr,
AgBrC42, etc.

The silver halide emulsion having internal fog nuclei preferably has a silver halide grain size of 0.1 to 0.7 .mu.-.

Further, the silver halide emulsion having internal fog nuclei is preferably a monodisperse emulsion. Here, the term "monodisperse emulsion" refers to one in which σ □≦0.20, where r is the average grain size of silver halide grains and σ is its standard deviation.

The surface latent image type silver halide emulsion has a silver iodide content of 0.5 to 1O
Contains mol%. The surface latent image type silver halide emulsion uses at least two types of surface latent image type silver halide emulsions having different average grain sizes.

The difference in average particle size is at least 0.1 μm.

The average grain size of surface latent image type silver halide emulsions can be determined by direct measurement from electron micrographs, by a Cole-Coup counter, or by using a centrifugal particle size distribution measuring device based on the liquid phase sedimentation method. . The shapes of the silver halide emulsion grains used in the present invention are cubic, hehedral, and tetradecahedral.
It may be spherical, potato-shaped, plate-shaped, etc.

The average grain size of the surface latent image type silver halide emulsion is 0.5 to 3.
Preferably it is μl. The silver halides present in this emulsion are AgBrI, AgBrC11, etc.
The l content is preferably 0 to 20 mol%. Further, the difference in silver iodide content between the one with the lowest silver iodide content and the next lowest silver iodide content is preferably 0.2 mol % or more.

For example, when AgBr1 is used as silver halide grains in a surface latent image type silver halide emulsion, the distribution of Ag1 inside the grain may be uniform, or it may be 4 degrees, which is higher in the inner part (or may be localized in the inner part). .

Note that when Ag+ is localized inside the grain, the inside refers to the distance from the center of the grain to 2/3 of the total amount of silver contained in the grain.

In addition, the surface latent image type silver halide emulsion is prepared by the so-called control double jet method, in which the pH and EAg in the reaction vessel are controlled by gradually increasing the amount of antiion/8 solution or halide solution added. can do. Iridium (Ir).

Thallium (IM), cadmium (Cd), palladium (
Pd) ions, etc. can be added at the time of particle formation.

Further, the surface latent image type silver halide emulsion is preferably a monodisperse emulsion. Here, a monodisperse emulsion is defined as the above-mentioned silver halide emulsion having internal fog nuclei, where the average grain size of silver halide grains is `` and its standard deviation is σ, σ □ ≦ 0.20. means something that is.

In the surface latent image type silver halide emulsion, those having the largest grain size have the highest sensitivity, and it is preferable that the amount of silver iodide contained in these grains is smaller than that of other grain sizes. In addition,
If the surface latent image type silver halide emulsion having the largest grain size has a higher silver iodide content than the other emulsions, the graininess may be poor and a smooth sensitometric curve may not be obtained.

Further, it is preferable that the surface latent image type emulsion is a monodisperse emulsion except for the emulsion having the maximum average grain size. Monodispersed emulsions have better graininess and can provide a smooth sensimetry curve with a high γ type.

A silver halide emulsion with internal fog and a surface latent image type silver halide emulsion may be mixed and then coated in the same layer, and a silver halide emulsion with internal fog may be mixed with a surface latent image type silver halide emulsion. The emulsions may be placed closer to the support and these emulsions may be in separate layers.

As a silver halide photographic light-sensitive material, the silver iodide content in the total silver halide is preferably 1 to 10 mol%.

Surface latent image type silver halide emulsions having different grain sizes can be appropriately chemically sensitized.

Chemical sensitization can be carried out using, for example, thiosulfate, allylthiocarbamide, thiourea, allyl isothiocyanate, cystine, p
- Sulfur sensitization using toluene thiosulfonate, rhodan, mercapto compounds, etc., and chlorauric acid, potassium chloroaurate, auric trichloride, potassium auric thiocyanate, potassium iodoaurate, tetracyanoauric acid, etc. There is gold sensitization,
These may be used in combination.

The amount of the sulfur sensitizer added varies within a considerable range depending on various conditions, but is usually about 10-7 to 10-2 mol per mol of silver. The amount of gold sensitizer added varies over a considerable range depending on various conditions, but it is usually 1 O- to 1 mole of silver.
It is on the order of 9 to 10-'' moles.

In addition, in sulfur/gold sensitization, the blending ratio of both varies depending on the aging conditions, etc., but usually the sulfur sensitizer is about 1-1000 mol per 1 mol of the gold sensitizer.

Further, the gold sensitizer may be added at the same time as the sulfur sensitizer, during the sulfur sensitization, or after the sulfur sensitization is completed.

Are these chemical sensitizers water-soluble compounds? The organic solvent-soluble compound is added as a solution in an organic solvent that is easily miscible with water, such as methanol or ethanol.

There are no particular restrictions on the conditions such as pH, pAg, temperature, etc. during chemical sensitization, but the pH value is preferably 4-9, especially 5-8, and the pAg value is kept at 5-11, especially 8-10. The temperature is preferably 40 to 90°C, particularly 45 to 75°C.

The photographic emulsion used in the light-sensitive material of the present invention is prepared by an acid method, a neutral method, or an ammonia method. Further, the reaction between the soluble silver salt and the soluble halogen salt may be carried out by any one of a one-sided mixing method, a simultaneous mixing method, and a combination thereof. A so-called back mixing method may be used, or a Chondral double jet method, which is a simultaneous mixing method, may be used.

At the stage of silver halide grain formation or physical ripening,
A cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt, or a complex salt thereof, a rhodium salt or a complex salt thereof, an iron salt or a complex salt thereof, etc. may be coexisting.

Further, the grain-wise silver iodide distribution of silver halide grains is determined by a method combining ion etching and X-ray charging spectroscopy.

Further, grains in which the distribution of silver iodide in the grains is uniform or more in the interior than on the surface can be prepared by various methods.

In addition to the above-mentioned sulfur sensitization and gold/sulfur sensitization, the photographic emulsion used in the present invention includes reducing substances X such as stannous salts, amines, hydrazine derivatives, formamidine sulfinic acid,
Reduction sensitization method using a silane compound): A noble metal sensitization method using a noble metal compound (e.g., complex salts of metals of group II of the periodic table such as PL, lr, and Pd in addition to zinc salts) can also be used in combination. .

In order to prevent capri and stabilize photographic performance during the manufacturing process, storage or photographic processing of photographic light-sensitive materials, various compounds can be included. i.e. azoles such as benzothiazolium salts, nitroindazoles, triazoles, benzotriazoles, benzimidazoles (especially nitro- or halogen-substituted)
: Heterocyclic mercapto compounds such as mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidoles, mercaptothiadiazoles, mercaptotetrazoles (especially 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines with dicarboxyl group, The above-mentioned heterocyclic mercapto compounds having a water-soluble group such as a sulfone group: thioketo compounds such as oxazolinthione: azaindenes such as tetraazaindenes (especially 4-hydroxy substituted (1,3,3a)).

7) Tetraazaindenes): Benzenethiosulfonic acids: Benzenesulfinic acids, etc. can be contained.

In the photographic light-sensitive material, a dispersion of a water-insoluble or poorly soluble synthetic polymer can be contained in the photographic emulsion layer and other hydrophilic colloid layers in order to improve dimensional stability and the like. For example, alkyl (meth)acrylate, alkoxyalkyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylamide, vinyl ester (e.g. vinyl acetate), acrylonitrile, olefin, styrene, etc. alone or in combination, or these and acrylic acid, A polymer containing a combination of methacrylic acid, α,β-unsaturated dicarboxylic acid, hydroxyalkyl (meth)acrylate, sulfoalkyl (meth)acrylate, styrene sulfonic acid, etc. as a monomer component can be used.

Photographic emulsions may be spectrally sensitized with methine dyes and others. Dyes include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, steryl dyes,
and hemiogisonol dyes. Particularly useful dyes are those belonging to the merocyanine dyes and complex merocyanine dyes. Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus for these dyes. That is, viroline nucleus, oxaprine nucleus, thiazoline nucleus, virol nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus,
Pyridine nuclei, etc.: Nuclei in which an alicyclic hydrocarbon ring is fused to these nuclei; and nuclei in which aromatic hydrocarbon rings are fused to these nuclei, i.e., indolenine nucleus, benzindolenine nucleus, indole nucleus, benzoxazole nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole nucleus,
A benzoselenazole nucleus, a benzimidazole nucleus, a quinoline nucleus, etc. are applicable. These nuclei may be substituted on carbon atoms.

Merocyanine dyes or composite merocyanine dyes include a pyrazolin-5-one nucleus, a thiohydantoin nucleus, and a 2-thioxazolidine-2 nucleus having a ketomethylene structure.
, 4-dione nucleus, thiazolidine-2,4-dione nucleus, rhodanine nucleus, thiobarbinuric acid nucleus, etc. can be applied.

The photographic emulsion layer of the photographic light-sensitive material of the present invention contains, for example, polyalkylene oxide or its derivatives such as ethers, esters, and amines, 1,000-onythyl compounds, thiomorpholines, etc., for the purpose of increasing sensitivity, increasing contrast, or accelerating development. Quaternary ammonium salt compounds, urethane derivatives,
It may contain urea derivatives, imidazole derivatives, 3-pyrazolidones, and the like.

As the binder or protective colloid for the photographic emulsion, for example, gelatin such as lime-treated gelatin, acid-treated gelatin, derivative gelatin, or gelatin graft polymer is preferably used, and hydrophilic colloids such as hydroxyethyl cellulose, polyvinyl alcohol, and polyvinylimidazole are used. can be used.

The photographic emulsion layer or other hydrophilic colloid layer of a photographic light-sensitive material contains a coating aid, an antistatic agent, a shearing property improver, an emulsifying dispersion agent,
Prevention of adhesion and improvement of photographic properties (e.g. development acceleration, contrast enhancement,
The following surfactants may be included for the purpose of exacerbation of symptoms).

That is, saponins (steroids), alkylene oxide derivatives (e.g. polyethylene glycol, polyethylene glycol/polypropylene glycol condensates, polyethylene glycol alkyl or alkylaryl ethers, ethers, polyethylene glycol, polyethylene glycol esters, polyethylene glycol sorghum esters, polyalkylene gelicol alkylamines or amides, polyethylene oxide adducts of silicones), glycidol derivatives (e.g. alkenylsuccinic acid polyglycerides, alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols, alkyl esters of sugars, etc. Ionic surfactants: alkyl carboxylates, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphate esters, N-acyl-N-alkyl taurines, sulfosuccinic acid Anions containing acidic groups such as carboxy groups, sulfo groups, phospho groups, phosphoric acid ester groups, sulfuric ester groups, etc., such as esters, sulfoalkyl polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl phosphate esters, etc. Ampholytic surfactants such as diamino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates or sulfuric esters, alkyl betaines, and amine oxides: alkylamine salts, aliphatic or aromatic quaternary ammonium salts,
Cationic surfactants such as heterocyclic quaternary ammonium salts such as pyridinium, imidazolium, and phosphonium or sulfonium salts containing aliphatic or heterocycles can be used.

Photographic emulsions may also contain color image-forming couplers. The color image-forming coupler is preferably a non-diffusive type having a hydrophobic ballast group in the molecule.

The color image-forming coupler may be 2-equivalent or 4-equivalent to silver ions. Color image-forming couplers may be those in which the product of the coupling reaction is colorless, and may also include colored couplers that have a color-correcting effect and so-called DIR couplers that release a development inhibitor or its precursor upon development. You may do so. In addition to the DIR coupler, the light-sensitive material may contain a compound that releases a development inhibitor during development.

As the yellow coloring coupler, an open chain ketomethylene coupler can be used. Among these, benzoylacetanilide and pivaloylacetanilide compounds are preferred.

As the magenta coupler, pyrazolone compounds, indacylon compounds, cyanoacetyl compounds, etc. can be used, and pyrazolone compounds are particularly preferred.

As the cyan coupler, phenolic compounds, naphthol compounds, etc. can be used.

Two or more types of the above couplers may be contained in the same layer, or the same compound may be contained in at least two different layers. The coupler can be incorporated into the silver halide emulsion layer by a method such as that disclosed in US Pat. No. 2,322,027.

The protective layer of the silver halide photographic light-sensitive material is made of a hydrophilic colloid, and specifically, the above-mentioned compounds are used. The protective layer may be a single layer or a multilayer.
An antistatic agent may also be included.

The emulsion layer or protective layer may contain at least one type selected from matting agents and smoothing agents;
The matting agent preferably contained in the protective layer has a particle size of 0.
．． A water-dispersible vinyl polymer having a thickness of 3 to 5 μm or more than twice the thickness of the protective layer (for example, polymethyl methacrylate), silver halide, barium strontium sulfate, or the like is used.

Smoothing agents are useful in preventing adhesion failures and are particularly effective in improving the frictional properties of motion picture films related to camera compatibility during side shadowing or projection. Smoothing agents include liquid paraffin, waxes such as esters of higher fatty acids, polyfluorinated hydrocarbons or their derivatives, polyalkylpolysiloxanes, polyarylpolysiloxanes, polyalkylarylpolysiloxanes, or alkylene oxide additions thereof. Silicones such as derivatives are used.

The silver halide photographic material of the present invention may optionally contain:
Antihalation layers, intermediate layers, filter layers, etc. can be provided.

The silver halide photographic light-sensitive material of the present invention can be applied to X-ray light-sensitive materials, lithographic light-sensitive materials, black-and-white photographic light-sensitive materials, color negative light-sensitive materials, and the like.

The silver halide photographic material of the present invention may contain a dye, a hardening agent, a fluorescent whitening agent, a color capri-preventing agent, an ultraviolet absorber, and the like, if necessary.

The photographic emulsion is then coated onto a flexible support such as plastic film, paper, or cloth, or a rigid support such as glass, ceramic, or metal by dip coating, roller coating, curtain coating, extrusion coating, etc. be done.

The flexible support may be a film consisting of a semi-synthetic or synthetic polymer such as cellulose nitrate, cellulose acetate, vinegar [a[cellulose, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate], a baryta layer or an α-olefin polymer (e.g. Paper coated or laminated with polyethylene, polypropylene, ethylene/butene copolymer, etc.

The emulsion layer using the silver halide photographic material of the present invention is
Formed on at least one surface of the support.

For photographic processing of the silver halide photographic material of the present invention, various methods can be applied using various processing solutions. The treatment temperature is from 18°C to 50°C, but may be higher than 18°C or lower than 50°C.

As for photographic processing, either black and white photographic processing or color photographic processing can be applied depending on the purpose.

When performing black and white photographic processing, use dihydroxybenzenes (
For example, hydroquinone), 3-pyrazolidones (N, t
(1-phenyl-3-pyrazolidone), aminophenols (e.g. N-methyl-p-aminophenol), 1
-Phenyl-3-pyrazolines, ascorbic acid, and the like can be included in the developer alone or in combination. The developing solution also contains preservatives, alkaline agents, pH buffering agents, and antifoggants (for example, methylbenzotriazole).
nitroindazole, etc.), and further contains solubilizers, color toning agents, development accelerators, surfactants, antifoaming agents, water softeners, hardeners, viscosity imparting agents, etc. There is. The pH of the developer should be 9 to 11, especially pH 9.
, 5 to 10.5 are preferred.

The silver halide photographic light-sensitive material of the present invention has a processing solution (for example,
It is one of the preferred embodiments that the processing is carried out in a developing bath, a pre-bath, etc., in an amount of about 1 to 20 g per addition 111. The photographic emulsion according to the present invention has low processing dependence in the above-mentioned processing G. It can also be processed with an automatic roller developing machine.

As the fixer, one having a commonly used composition can be used.

As the fixing agent, in addition to thiosulfates and thiocyanates, organic sulfur compounds known to be effective as fixing agents can be used.

The fixing solution may contain a water-soluble aluminum salt as a hardening agent.

Color developers generally consist of an alkaline aqueous solution containing a color developing agent. The color developing agent is a primary aromatic amine developer, such as phenylene diamines (e.g. 4-amino-N, N-diethylaniline, 3-methyl-4-amino-N, N-diethylaniline, 4-amino-N-ethyl -N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-
β-methanesulfamide ethylaniline, 4-amino-
3-methyl-N-ethyl-N-β-methoxyethylaniline, etc.) can be used.

Color developer is made of other alkali metals! pH 1, U buffering agents such as thatates, carbonates, borates and phosphates, development inhibitors or antifoggants such as bromides, iodides and organic antifoggants can be included. If necessary, water softeners, preservatives such as hydroxylamine, organic solvents such as benzyl alcohol and diethylene glycol, development accelerators such as polyethylene glycol, quaternary ammonium salts, and amines, dye-forming couplers, competitive couplers, A fogging agent such as sodium borohydride, an auxiliary developer such as 1-phenyl-3-pyrazolidone, a viscosity imparting agent, etc. may also be included.

After color development, the photographic emulsion layer is usually bleached. The bleaching process may be performed simultaneously with the fixing process, or may be performed separately. Bleach agents include Fe'', Co°', and C.
Compounds of polyvalent metals such as r'', Cu''2, peracids, quinones, nitrone compounds, etc. are used. For example, ferricyanide, ■ chromate, organic complex salts of Fe゛3 or CO゛3, aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, 1゜3-diamino-2-propatoltetraacetic acid, or citric acid. , tartaric acid,
Complex salts of organic acids such as malic acid: persulfates, permanganates: nitrosophenols, etc. can be used. Of these, potassium ferricyanide, sodium iron(I[I) ethylenediaminetetraacetate, and ammonium iron(III) ethylenediaminetetraacetate are particularly useful. Ethylenediaminetetraacetic acid iron(III) complex salts are useful in both stand-alone bleach solutions and -bath bleach-fix solutions.

Various additives can also be added to the bleach or bleach-fix solution.

The silver halide photographic material of the present invention is not normally used as a reversal film.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to Examples.

However, it goes without saying that the present invention is not limited to the examples.

Example 1 Preparation of an emulsion with internal fog cores (Emulsion I with internal capri cores) A 2% gelatin solution was kept at 60°C, and an aqueous silver nitrate solution and an aqueous halide solution containing potassium bromide and sodium chloride were simultaneously added thereto. did. After the addition, the temperature of this solution was lowered to 40°C and desalted, and the average particle size was 0.26.
μm silver chlorobromide emulsion (ratio of Br and CI is 25:7
5) was obtained. The resulting emulsion was maintained at 60° C., an aqueous silver nitrate solution was added thereto, potassium auric thiocyanate was further added, and the emulsion was aged for about 50 minutes to form internal capri nuclei. Add potassium bromide aqueous solution to this solution to reduce pAg to 7.
．． 3, and an aqueous silver nitrate solution and an aqueous solution containing potassium bromide and potassium iodide were added at the same time. After desalting, 5-mercapto-1-phenyltetrazole was added in an amount of 150 μm per mole of silver to obtain emulsion I having fog nuclei inside. This emulsion has an average grain size (r) of 0
．． 35 μs, a/r was 0.11.

(Emulsion ■ having internal capri cores) A 2% gelatin solution was kept at 60° C., and an aqueous silver nitrate solution and an aqueous potassium bromide solution were simultaneously added thereto.

Thereafter, the temperature of this solution was lowered to 40 DEG C. and a desalting treatment was performed to obtain a silver bromide emulsion having an average grain size of 0.26 .mu.m.

Then, the same procedure as for emulsion 1 having internal fog nuclei was carried out to obtain emulsion 2 having internal fog nuclei. This emulsion had an average grain size (r) of 0.35 μm and σ/r of 0°12.

Surface Latent Image Tone I (Emulsion A) A 1.6% aqueous gelatin solution containing 1.3 g of potassium iodide and 80 g of potassium bromide was kept at 56°C, and an ammoniacal silver ion solution containing 11,100 g of nitric acid was added to the solution. These were divided into equal parts and added by a single jet method and a regular mixing method, respectively.The average particle size was controlled by changing the interval time between addition of the ammoniacal silver ions divided into three equal parts.

Note that when adding the ammoniacal silver ion solution, the second and third additions were partially neutralized with acetic acid.

Then, after the third addition was completed, Ostwald ripening was performed, the pH was adjusted to 6, and desalination was performed by the precipitation method, resulting in an irregularly shaped potato-shaped iodine with a silver iodide content of 1.3 mol%. An emulsion of silver bromide grains was obtained. This emulsion has an average grain size (r
) was 1.2 μm, and σ/r was 0.26.

Hypo, chloroauric acid and ammonium thiocyanate were added to this emulsion for gold/sulfur sensitization, and 4-hydroxy-6-methyl-1,3,3a,7-chitrazaindene was added to obtain emulsion A.

(Emulsion B) An emulsion was prepared in the same manner as Emulsion A except that potassium iodide was changed to 4.5 g, and an emulsion having a silver iodide content of 4.5 mol % and having a somewhat approximate disk shape was obtained. The average grain size D) of this emulsion is 1
．． 02 μm, and σ/r was 0.29.

The above emulsion was chemically ripened in the same manner as emulsion A to form emulsion B.
I got it.

(Emulsion C) An emulsion was prepared in the same manner as in the emulsion layer except that 4.0 g of potassium iodide was used to obtain an emulsion having a shape similar to emulsion B containing 4.0 mol % of silver iodide. Average grain size (r) of this emulsion
was 0.8 μ..., and σ/r was 0.28.

The above emulsion was chemically ripened in the same manner as Emulsion A to form Emulsion C.
I got it.

(Emulsion D) An emulsion was prepared in the same manner as Emulsion A except that potassium iodide was changed to 2.0 g, and an emulsion having a silver iodide content of 2.0 mol % and having a shape somewhat close to a disk was obtained. The average grain size (r) of this emulsion was 1.10 μm, 11.7 F/r, 0.26.

The above emulsion was chemically ripened in the same manner as Emulsion A to obtain an emulsion.

1. Results: A silver halide photographic emulsion containing the same amount of polyethylene oxide and 1-phenyl-5-mercaptotetrazole was added to the silver amount per resist as shown in Table 1.
Both sides of the polyethylene terephthalate support were coated in coating amounts as shown in Ilh 1 to Ilh 5.

Then, gelatin, polymethyl methacrylate, and a glycidol addition polymer of phenol-formalin condensate were added as antistatic agents, and formalin and glyoxal hardeners were mixed and coated on these emulsion layers to form a protective layer.

Then 0.2? ! Using a continuous roller conveyance type automatic developing machine that applies standard exposure through a light wedge in one-time increments and performs development, fixing, and water washing processes in an integrated manner,
High-temperature rapid processing was performed at 40° C. for 30 seconds using the following developer formulation.

(Developer formulation) Anhydrous sodium sulfite 70g Hydroquinone 10g Boric anhydride
1g sodium sulfate water salt
20 g 1-phenyl-1,3-pyrazolidone 0.35 g Sodium hydroxide
5g5-methyl-benzotriazole o,
o s g potassium bromide
5g glutaraldehyde bisulfite 15g glacial acetic acid 8g Add water II! Finished.

The degree of silver of these developed, fixed and washed samples and comparative samples was measured using a densitometer, and the true performance (maximum 7; degree (1) max) obtained from this measured value.

Sensitivity (S), γ value) are shown in Table 1. In the table, the sensitivity value and the maximum sensitivity value of 7 are expressed as relative values when the value of sample Nl11 is taken as 100. In addition, graininess was visually determined.

As a result, sample No. 5 in Table 1 had good graininess despite having a small silver content of 4.5 g/d, and had the highest/seismic intensity.
It was found that the sensitivity and T value were good. In addition, sample floors 1 to 4 in Table 1 are the highest concentrations and sensitivities.

It was found that both T value and graininess characteristics were inferior to Sample IIk15.

The following margins: :・, ″′ Example 2 Preparation of RA3-Dispersion Planar Image Le 1 Silver Halide Emulsion (Emulsion E) A monodispersed silver iodobromide emulsion containing 2 mol% of silver iodide was processed by control double jet. The average grain size (r) of this emulsion was 0.25μ-1σ/r20.10.

Using this emulsion as a seed crystal, a monodisperse emulsion in which 30 mol % of silver iodide was localized inside the grains was prepared. For flower tailing, first add 0.6N ammonium ion to a mixing pot at 40°C, and during growth, pA g = 7.35 and pH = 9.
．． 8. The temperature inside the pot was maintained at 40°C.

Furthermore, the monodispersed emulsion in which silver iodide was localized inside the grains was covered with a shell of pure silver bromide by the control jet method. The shape of the particles was cubic. Furthermore, potassium bromide was added to bring the pA and g to 11, and acetic acid was added to adjust the pH.
8 and aged at 40°C for 15 minutes. The emulsion thus obtained had an average grain size (') of 0.9.crm,
I/r=0.12, total silver iodide content was 3 mol%, and pure silver bromide shell thickness was 0.26 μm. This emulsion was desalted and optimally chemically sensitized by adding hypo, chloroauric acid and ammonium thiocyanate, and then 4-hydroxy-6-methyl-1,3,3a,? -Tetrazaindene was added to prepare emulsion E.

(Emulsion F) In the same manner as Emulsion E, the average grain size (r) was 0.6 μ..., σ
An emulsion F was obtained in which /r was 0.13, total silver bromide was 4 mol %, and pure silver bromide had a shell thickness of 0.08 μm.

Preparation of J material and test results In the same manner as in Example 1, a surface latent image type silver halide emulsion and
A silver halide emulsion having internal fog was coated on both sides of a polyethylene terephthalate support at a silver coating weight of samples 6 to 8 in Table 2. Then, in the same manner as in Example 1, the maximum 7 degree of density, sensitivity, y(i!, and graininess) were measured. The measurement results are shown in Table 2. From Table 2, sample 1?
,? It can be seen that by using monodispersed emulsions E and F, b8 has a maximum concentration of [1 of 4.5 g/m, high sensitivity without a decrease in T value, and improved graininess. . Note that FIG. 1 shows the particle size distribution curve of the sample magnet 6 as A and the particle size distribution curve of sample magnet 7 as the beginning.

Sample No. 7 prepared by mixing the emulsion has three peaks in the particle size distribution.

Next, silver halide emulsion I having internal fog.

In order to make a comparison (2), a surface latent image type emulsion and a silver halide emulsion with internal fog were coated on a polyethylene terephthalate support in the same manner as in Example I so that the silver coating amount became Sample Arashi 9 to N113 in Table 3. was applied on both sides. Then, using Ace Doll manufactured by Konishiroku Photo Industry Co., Ltd. as a developer,
Maximum density, sensitivity, T value, and graininess were measured in the same manner as in Example 1, except that the film was treated at 0° C. for 4 minutes and fixed using Ace Fix manufactured by Konishiroku Photo Industry Co., Ltd. The measurement results are shown in Table 3. From Table 3, it was found that Emulsion I, which had internal fog, had higher sensitivity and better silver tone.

Here, the pure black the silver tone is, the higher the evaluation is, and the more yellowish it is, the worse it is.

〔Effect of the invention〕

As described above, according to the present invention, a silver halide photographic material having uniform gradation, excellent graininess, and high sensitivity despite having a low silver content can be obtained.

[Brief explanation of drawings]

FIG. 1 is a graph showing the particle size distribution of the material used in one example of the present invention. 41 pieces: particle size distribution curve.

Claims (1)

[Scope of Claims] 1. In a silver halide photographic light-sensitive material that uses a surface latent image type silver halide emulsion and a silver halide emulsion having internal fog nuclei in combination, the surface latent image type silver halide emulsion has an average grain A silver halide photographic material comprising at least two types of silver halide materials having different diameters. 2. Among surface latent image type silver halide emulsions containing at least two types of emulsions with different average grain sizes, the silver iodide content of the emulsion with the largest average grain size is higher than that of other surface latent image type silver halide emulsions. The silver halide photographic light-sensitive material according to claim 1, characterized in that the silver iodide content is less than that of . 3. Claims 1 or 2, characterized in that at least one type of surface latent image type silver halide emulsion containing at least two types of emulsions with different average grain sizes is a monodisperse emulsion. The silver halide photographic material described in Section 1.