JPH0922080A - Photosensitive silver halide emulsion and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the emulsion high in sensitivity and contrast and superior in graininess. SOLUTION: The silver halide emulsion is a silver iodobromide emulsion comprising >=95% cubic or tetradecahedral crystal grains comprising mainly (200) faces and the silver iodobromide grains have an average silver iodide content of 5-10mol% and the relative standard deviation of the silver iodide content of each grain of <=20%. This emulsion is prepared by adding an aqueous solution of silver salt and an aqueous solution of halide into an aqueous solution of gelatin in the presence of a silver halide solvent at the same time, while keeping pAg constant in the range of 7.0-8.3.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a silver halide emulsion, and more particularly to a photosensitive silver halide emulsion having improved sensitivity, contrast and graininess.

[0002]

2. Description of the Related Art In recent years, the demand for silver halide emulsions for photography has become more and more stringent, and higher and higher standards have been demanded for photographic performance such as high sensitivity, high contrast and excellent graininess. . In order to achieve photographic properties such as high sensitivity, high contrast and excellent graininess, a so-called monodisperse silver halide emulsion having a narrow grain size distribution, as described in JP-A-52-153428, is used. Although known to be advantageous, they are not always sufficiently effective to meet the current high standards of demand. On the other hand, it is considered that narrowing the distribution of halogen composition between grains is preferable for obtaining a high-contrast emulsion.

As a method for evaluating the halogen composition distribution of emulsion grains, a powder X-ray diffraction method as described in, for example, Japanese Patent Application Laid-Open No. 56-110926 has been conventionally used. Is not sufficient, it is difficult to evaluate the inter-grain halogen composition distribution, which is a subtle but practically problematic as described below, and the inter-grain halogen composition distribution and the intra-grain halogen composition distribution are separated. Therefore, it was practically impossible to evaluate the inter-grain halogen composition distribution of the grains having the intra-grain halogen composition distribution like the core / shell type emulsion of the present invention. Therefore, although studies on emulsions in which the grain size distribution of emulsion grains is monodisperse have been extensively conducted so far, design guidelines for emulsions that meet practical requirements from the viewpoint of narrowing the halogen composition distribution between grains. It was impossible to get. Therefore, when we newly applied an X-ray micro-analyzer for this purpose and measured the halogen composition of individual grains of the silver iodobromide emulsion, it was confirmed that there were large variations in the halogen composition of the emulsion grains. However, it has become clear that this is a cause of impairing photographic performance. By setting the relative standard deviation of the silver iodide content of individual silver iodobromide grains to 20% or less, it is possible to obtain an emulsion having extremely high sensitivity, high contrast and excellent graininess. Found.

[0004]

An object of the present invention is to provide a silver halide emulsion having high sensitivity, high contrast and excellent graininess. Another object of the present invention is to provide a method for producing a silver halide emulsion having high sensitivity, high contrast and excellent graininess.

[0005]

These objects of the present invention are silver iodobromide emulsions consisting essentially of (1) cubic or tetradecahedral crystal grains consisting mainly of (200) faces, The average silver iodide content of the silver iodobromide grains is 5 mol% or more, and the relative standard deviation of the silver iodide content of each grain is 2
0% or less of the light-sensitive silver halide emulsion, and (2) the emulsion containing an aqueous solution of a water-soluble silver salt and a water-soluble alkali metal halide in a gelatin aqueous solution in the presence of a silver halide solvent. It was achieved by a manufacturing method characterized in that an aqueous solution is added at the same time while maintaining a constant pAg value within a range of pAg 7.0 to 8.3.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Here, “a tetradecahedron mainly composed of (200) planes” means that 50% or more of the surface area of particles is (20
0) means a tetradecahedron as occupied by faces. In the silver halide emulsion of the present invention, the phrase "substantially consists of cubic crystals or tetradecahedral crystal grains mainly composed of (200) planes" means that at least 95% of the emulsion grains are cubic crystals or It may be a tetradecahedral crystal mainly composed of (200) faces, and the remaining particles of less than 5% are twin crystals, octahedron, or mainly
It may be a tetradecahedral crystal having a (III) plane. The relative standard deviation of the silver iodide content of each grain in the present invention is 20.
% Or less, but particularly preferably 10% or less. The silver iodide content of each emulsion grain can be measured by analyzing the composition of each grain using, for example, an X-ray micro analyzer. The term "relative standard deviation of the iodide content of individual grains" as used herein means, for example, the silver iodide content when the silver iodide content of at least 100 emulsion grains is measured by an X-ray microanalyzer. It is a value obtained by multiplying the value obtained by dividing the standard deviation of by the average silver iodide content by 100.

The specific method for measuring the silver iodide content of individual grains is as follows. First, a sample emulsion is diluted 5 times with distilled water, a proteolytic enzyme such as pronase is added, and the mixture is kept at 40 ° C. for 3 hours to decompose gelatin. Next, the sample is centrifuged to sediment the emulsion particles, and after removing the supernatant, distilled water is added again to redisperse the emulsion particles in distilled water. After repeating this washing operation twice, the sample is dispersed on the sample stage. After drying, carbon vapor deposition is performed and the measurement is performed with an X-ray micro analyzer. The X-ray micro analyzer may be a commercially available general device, and no special specifications are required. In the present invention, the Shimadzu X-ray micro analyzer EMX-
SM was used. The measurement is performed by irradiating each particle with an electron beam and measuring the characteristic X-ray intensity of the element in the particle excited by the electron beam with a wavelength-dispersive X-ray detector. Spectroscopic crystal used for analysis of each element and characteristics X of each element
The wavelength of the line is as shown in Table 1. In order to determine the silver iodide content of the grain from the characteristic X-ray intensity of each element, the same measurement was carried out in advance for grains of known silver iodide content, and a calibration curve as shown in FIG. 1 was obtained. It may be prepared in advance and calculated from the calibration curve.

[0008]

[Table 1]

The silver iodobromide emulsion of the present invention is water-soluble in an aqueous gelatin solution in the presence of a solvent for silver halide, preferably 0.1 mol or more of silver halide solvent per mol of silver salt. It can be prepared by simultaneously adding an aqueous solution of a silver salt and an aqueous solution of a water-soluble alkali metal halide while keeping pAg constant within the range of 7.0 to 8.3. More preferable for narrowing the silver iodide content distribution between grains is the above-mentioned production method in which 0.5 mol or more of a silver halide solvent is present per 1 mol of silver salt during silver halide formation. . In order to narrow the distribution of silver iodide content between grains, it is more preferable that the pAg during addition is from 8.0 to 8.3.
The above-mentioned production method is characterized in that it is kept constant within the range.

As the silver halide solvent that can be used in the present invention, any of the silver halide solvents well known in the art such as thioether compounds, thiourea compounds, thiocyanates and ammonia can be used. In particular, ammonia is preferably used. In the present invention, an aqueous solution of silver nitrate and an aqueous solution of an alkali metal halide (eg potassium iodide, potassium bromide) are added at the same time while maintaining a constant pAg. It is preferable that the supersaturation degree of the solution during addition is high. , US Pat. No. 4,242,44
The method described in No. 5 is preferable, in which the crystal growth rate is 30 to 100% of the critical crystal growth rate, and the addition solution is added while increasing the concentration thereof. Similar to increasing the concentration of the solution, it may be added while increasing the addition rate. In the present invention, in the process of silver halide grain formation or physical ripening, cadmium salt, zinc salt, lead salt, thallium salt, iridium salt or its complex salt, rhodium salt or its complex salt, iron salt or iron complex salt, etc. May coexist.

The cubic or tetradecahedral grains of the present invention may have a so-called core / shell structure. When a core / shell structure is adopted, a core is formed by a control double jet method with pAg 7.0 to 8.3 in the presence of a silver halide solvent as described above, and then a water-soluble silver salt aqueous solution is further formed thereon. Also, the shell can be formed by a control double jet method using a water-soluble alkali metal halide aqueous solution. The halogen composition of the shell is preferably silver iodobromide or silver bromide having a silver iodide content of less than 5 mol%. The silver iodide content in the emulsion of the present invention is preferably 5 to 10 mol%. When the core / shell structure is adopted, the silver iodide content of the core is preferably 5 to 20 mol%.

The silver halide emulsion of the present invention is chemically sensitized. For chemical sensitization, for example, D. Gru edited by H. Frieser
ndlagen der Photographischen Prozesse mit Silberha
log-eniden (Akrdemische Verlagsgesellschaft, 1968)
The method described on pages 675 to 734 can be used. That is, a sulfur sensitization method using a compound containing sulfur capable of reacting with active gelatin or silver (for example, thiosulfate, thioureas, mercapto compounds, rhodanines); a reducing substance (for example, first tin salt, Amines, hydrazine derivatives,
Reduction sensitization method using formamidinesulfinic acid, silane compound; noble metal compound (eg, gold complex salt, P
A noble metal sensitization method using a complex salt of a metal of VIII such as t, Ir and Pd of the periodic table) can be used alone or in combination.

These specific examples are described in US Pat. Nos. 1,574,944 and 2,410,6 regarding the sulfur sensitization method.
No. 89, No. 2,278,947, No. 2,728,
Nos. 2,983,609 and 2,4 regarding reduction sensitization methods, such as No. 668 and No. 3,656,955.
No. 19,974, No. 4,054,458, etc., and noble metal sensitization methods are described in US Pat. Nos. 2,399,083, 2,448,060, and British Patent 618,061. It is described in the specification. Gelatin is advantageously used as a protective colloid used in the preparation of the silver halide photographic emulsion of the present invention and as a binder for other hydrophilic colloid layers, but other hydrophilic colloids can also be used. .

For example, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfates, sugar derivatives such as sodium alginate and starch derivatives. A variety of synthetic hydrophilic polymer substances such as polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole, and other single or copolymers; Can be used. In addition to lime-processed gelatin, acid-processed gelatin and Bull.Soc.Sci.Phot.Japan,
The enzyme-treated gelatin as described in No. 16, P. 30 (1966) may be used, and a hydrolyzate or an enzymatic hydrolyzate of gelatin may also be 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, such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles. , Benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (particularly 1-phenyl-5-mercaptotetrazole), etc .; mercaptopyrimidines; mercaptotriazines; thioketo compounds such as oxadrinethione; azaindenes, such as tria Theindenes, tetraazaindenes (particularly 4-hydroxy-substituted (1,3,
3a, 7) Tetraazaindenes), pentaazaindenes and the like; addition of many compounds known as antifoggants or stabilizers such as benzenethiosulfonic acid, benzenesulfinic acid, benzenesulfonamide and the like. Can be. For example, U.S. Pat. No. 3,954,47
No. 4, No. 3,982, 947, Japanese Patent Publication No. 52-28, 6
Those described in No. 60 can be used.

In the photographic emulsion layer of the photographic light-sensitive material of the present invention, for the purpose of increasing sensitivity, increasing contrast, or promoting development,
For example, polyalkylene oxide or its derivative such as ether, ester, amine, thioether compound, thiomorpholinic acid, quaternary ammonium salt compound, urethane derivative, urea derivative, imidazole derivative, and 3-pyrazolidones may be included. For example, US Pat.
00,532, 2,423,549, 2,71
No. 6,062, No. 3,617,280, No. 3,77
Those described in 2,021, 3,808,003, British Patent 1,488,991 and the like can be used.

The photographic emulsion used in the present invention may be spectrally sensitized with methine dyes and the like. Dyes used include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes, and complex merocyanine dyes. Any of the nuclei usually used for cyanine dyes as basic heterocyclic nuclei can be applied to these dyes. That is, a pyrroline nucleus, an oxazoline nucleus, a thiazoline nucleus, a pyrrole nucleus, an oxazole nucleus,
Thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc .; nucleus in which alicyclic hydrocarbon ring is fused to these nuclei; and nucleus in which aromatic hydrocarbon ring is fused to these nuclei, that is, indolenine A nucleus, a benzindolenine nucleus, an indole nucleus, a benzoxadol nucleus, a naphthoxazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzoselenazole nucleus, a benzimidazole nucleus, a quinoline nucleus and the like can be applied. These nuclei may be substituted on carbon atoms.

In the merocyanine dye or the complex merocyanine dye, as a nucleus having a ketomethylene structure, a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thiooxazolidine-2,4-dione nucleus, a thiazolidine-2,4-
A 5- to 6-membered heterocyclic nucleus such as a dione nucleus, a rhodanine nucleus, and a thiobarbituric acid nucleus can be applied. These sensitizing dyes may be used alone or in combination, and a combination of sensitizing dyes is often used particularly for supersensitization. A representative example is U.S. Pat.
8,545, 2,977,229, 3,39
7,060, 3,522,052, 3,52
No. 7,641, No. 3,617,293, No. 3,62
8,964, 3,666,480, 3,67
2,898, 3,679,428, 3,70
No. 3,377, No. 3,769,301, No. 3,81
4,609, 3,837,862, 4,02
6,707, British Patents 1,344,281, 1,507,803, and Japanese Patent Publication No. 43-4936, 5
3-12,375, JP-A-52-110,618,
No. 52-109,925.

Along with the sensitizing dye, a dye having no spectral sensitizing effect itself or a substance which does not substantially absorb visible light and exhibits supersensitization may be contained in the emulsion. The light-sensitive material prepared by using the present invention may contain a water-soluble dye as a filter dye in the hydrophilic colloid layer or for various purposes such as prevention of irradiation. Such dyes include oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes,
Cyanine dyes and azo dyes are included. Among them, oxonol dyes; hemioxonol dyes and merocyanine dyes are useful. In the photosensitive material prepared by using the present invention, the photographic emulsion layer and other hydrophilic colloid layers may contain a stilbene-based, triazine-based, oxazole-based or coumarin-based brightener. These may be water-soluble, or a water-insoluble brightener may be used in the form of a dispersion.

In carrying out the present invention, the following known anti-fading agents may be used in combination, and the color image stabilizers used in the present invention may be used alone or in combination of two or more kinds. Known anti-fading agents include, for example, U.S. Pat. Nos. 2,360,290, 2,418,613, 2,675,314, 2,701,197 and 2,704,713. No. 2,728,659, No. 2,732,300, No. 2,735,765, No. 2,710,801, No. 2,816,028, and British Patent No. 1,363,921. Hydroquinone derivatives described in US Pat. Nos. 3,457,079 and 3,
Gallic acid derivatives described in, for example, 069,262, U.S. Pat. Nos. 2,735,765 and 3,698,909.
P-alkoxyphenols described in JP-B Nos. 49-20977 and 52-6623, U.S. Pat. Nos. 3,432,300, 3,573,050, and 3,574,627; No. 3,764,337, JP-A Nos. 52-35633, 52-147434 and 5
There are p-oxyphenol derivatives described in 2-152225, bisphenols described in US Pat. No. 3,700,455, and the like.

The light-sensitive material produced by using the present invention may contain a hydroquinone derivative, an aminophenol derivative, a gallic acid derivative, an ascorbic acid derivative or the like as a color fog inhibitor. The silver halide photographic light-sensitive material produced by using the present invention may be either a black-and-white light-sensitive material or a multi-layered multi-colored light-sensitive material. Highly preferred due to sensitivity, high contrast and excellent graininess.

Multilayer natural color photographic materials usually have at least one red-sensitive emulsion layer, one green-sensitive emulsion layer and one blue-sensitive emulsion layer on a support. The order of these layers can be arbitrarily selected as needed. Usually, a cyan-forming coupler is contained in the red-sensitive emulsion layer, a magenta-forming coupler is contained in the green-sensitive emulsion layer, and a yellow-forming coupler is contained in the blue-sensitive emulsion layer.

As the yellow color coupler, a known open chain ketomethylene type coupler can be used. Among these, benzoylacetanilide compounds and piparoylacetanilide compounds are advantageous. Specific examples of the yellow color-forming coupler that can be used include U.S. Pat. Nos. 2,875,057, 3,265,506, 3,408,194, 3,551,155, and 3,582,322. , 3,725,072, 3,891,445, West German Patent 1,547,868, West German Application Publication 2,219,
917, 2,261,361, 2,414,0
06, British Patent No. 1,425,020, Japanese Patent Publication No. 51
-10783, JP-A-47-26133, 48-
73147, 51-102636, 50-63.
No. 41, No. 50-123342, No. 50-13044.
No. 2, No. 51-21827, No. 50-87650,
Nos. 52-82424 and 52-115219.

As the magenta color forming coupler, a pyrazolone compound, an indazolone compound, a cyanoacetyl compound and the like can be used, and the pyrazolone compound is particularly advantageous. Specific examples of magenta color forming couplers that can be used include U.S. Pat. Nos. 2,600,788 and 2,983.
No. 608, No. 3,062,653, No. 3,127,2
No. 69, No. 3,311,476, No. 3,419,39
No. 1, No. 3,519, 429, No. 3, 558, 319
No. 3,582,322, 3,615,506
Issue No. 3,834,908 Issue No. 3,891,445
Issue, West German patent 1,810,464, West German patent application (O
LS) No. 2,408,665, No. 2,417,945
No. 2, ibid. 2,418,959, ibid. 2,424,467
No. 4, JP-B-406031, JP-A-51-20826
No. 52-58922, No. 49-129538,
49-74027, 50-159336, 5
2-42121, 49-74028, 50-6
No. 0233, No. 51-26541, No. 53-5512.
No. 2 and the like.

As the cyan color coupler, a phenol compound, a naphthol compound or the like can be used. Specific examples thereof include U.S. Pat. Nos. 2,369,929, 2,434,272, 2,474,293, 2,521,908, 2,895,826 and 3,034. No. 892, No. 3,311,476, No. 3,458,315, No. 3,476,563, No. 3,583,971, No. 3,591,383, No. 3,767,411. No. 4,004,929, West German patent application (OLS) 2,414,830, 2,45
4,329, JP-A-48-59838, 51-2.
No. 6034, No. 48-5055, No. 51-14682
No. 8, No. 52-69624, No. 52-90932. As a cyan coupler, JP-A-57
-204545, 56-65134, 58-3
Couplers having an ureido group described in Nos. 3252 and 58-33249 can be preferably used.

Colored couplers include, for example, US Pat. Nos. 3,476,560 and 2,521,908.
No. 3,034,892, JP-B-44-2016
No. 38-22335, No. 42-11304, No. 44-32461, JP-A No. 51-26034, No. 52-42121, West German patent application (OL
S) 2,418,959 can be used.

Examples of the DIR coupler include US Pat. Nos. 3,227,554, 3,617,291, 3,701,783, 3,790,384 and 3,632,345. , West German Patent Application (OLS) 2, 4
14,006, 2,454,301, 2,45
4,329, British Patent No. 953,454, JP-A-5
2-69624, 49-122335, Japanese Patent Publication 5
Those described in No. 1-16141 can be used. DI
In addition to the R coupler, a compound which releases a development inhibitor upon development may be contained in the light-sensitive material. For example, US Pat. Nos. 3,297,445 and 3,379,529.
No. 2, West German Patent Application (OLS) 2,417,914, JP-A Nos. 52-15271 and 53-9116 can be used. Also, JP-A-57-150
A coupler which releases a development accelerator or a fog-generating agent as it is developed as described in JP-A No. 845 can be particularly preferably used. These couplers are generally added in an amount of 2 × 10 ^{−3 to} 5 × 10 ⁻¹ mol, preferably 1 × 10 ^{−2 to} 5 × 10 ⁻¹ mol per mol of silver in the emulsion layer.

The light-sensitive material produced by using the present invention may contain an ultraviolet absorber in the hydrophilic colloid layer. For example, benzotriazole compounds substituted with an aryl group (for example, those described in US Pat. No. 3,533,794), 4-thiazolidone compounds (for example, US Pat.
Nos. 314,794 and 3,352,681), benzophenone compounds (for example, JP-A-46-27).
No. 84), cinnamic acid ester compounds (for example, US Pat. Nos. 3,705,805 and 3,707,3).
75), butadiene compounds (for example, those described in US Pat. No. 4,045,229), or benzoxoxide compounds (for example, US Pat.
No. 700,455) can be used. Further, U.S. Pat. No. 3,499,762, Japanese Patent Laid-Open No.
Those described in 4-48535 can also be used.
An ultraviolet-absorbing coupler (for example, an α-naphthol-based cyan dye-forming coupler) or an ultraviolet-absorbing polymer may be used. These ultraviolet absorbers may be mordanted to a specific layer.

For the photographic processing of the light-sensitive material of the present invention, any known method can be used, and known processing solutions can be used. The processing temperature is usually
The temperature is selected between 18 ° C and 50 ° C, but may be lower than 18 ° C or higher than 50 ° C. Depending on the purpose, either a development process for forming a silver image (black and white photographic process) or a coupler photographic process including a development process for forming a dye image can be applied. In particular, when parallel development processing is typified by color development, extremely favorable results are obtained in terms of sensitivity and graininess.

The color developing solution generally comprises an alkaline aqueous solution containing a color developing agent. Color developing agents include known primary aromatic amine developers such as phenylenediamines (eg, 4-amino-N, N-diethylaniline,
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-methanesulfoamidoethylaniline, 4-amino-3-methyl-N-ethyl-N-β-methoxyethylaniline and the like) can be used.

The photographic emulsion layer after color development is usually bleached. The bleaching process may be performed simultaneously with the fixing process, or may be performed individually. Examples of bleaching agents include iron
Compounds of polyvalent metals such as (III), cobalt (III), chromium (VI) and copper (II), peracids, quinones, nitroso compounds and the like are used. For example, ferricyanide, dichromate, iron (III) or cobalt (III) organic complex salts such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, 1,
Aminopolycarboxylic acids such as 3-diamino-2-propanoltetraacetic acid, or complex salts of organic acids such as citric acid, tartaric acid and malic acid; persulfates, permanganates and nitrosophenol can be used. Of these, potassium ferricyanide and ethylenediaminetetraacetic acid iron (II
I) Sodium and ammonium iron (III) tetraethylenediaminetetraacetate are especially useful. The ethylenediaminetetraacetic acid iron (III) complex salt is useful both in a stand-alone bleaching solution and in a one-bath bleach-fixing solution. Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0032]

【Example】

 Example 1 A silver iodobromide emulsion was prepared using the solutions shown in Table 2.

[0033]

[Table 2]

Solution B and solution C were added over 5 minutes while adjusting the flow rate of solution C so that pAg was 8.25. Further, the solution D and the solution E were added over 90 minutes while adjusting the flow rate of the solution E so that the pAg was 8.28. The emulsion obtained is called EM-1. While adjusting the flow rate of solution C so that pAg of solution A becomes 8.28, solution B
And Solution C was added over 5 minutes. Furthermore, pAg is 7.03
The solution D and the solution E were added in 90 minutes, adjusting the flow rate of the solution E so that it might become. The emulsion obtained is called EM-2. The solution B and the solution C were added to the solution A over 5 minutes, adjusting the flow rate of the solution C so that pAg might be 8.28.
Furthermore, the solution D and the solution E were added in 90 minutes, adjusting the flow rate of the solution E so that pAg might be set to 6.5. The emulsion obtained is called EM-3.

Table 3 shows the grain sizes and grain size distributions of the emulsions EM-1, 2 and 3 measured with a Coulter counter and the intergranular silver iodide content distribution measured with an X-ray microanalyzer. The grain size and the grain size distribution are almost the same in the emulsions EM-1, 2 and 3, but the inter-grain silver iodide distribution becomes wider in the order of EM-1, 2 and 3. The emulsions of EM-1, 2 and 3 were desalted and washed by a conventional method, and the pH was adjusted to 6.5 and pAg of 9.0 at 63 ° C, and then each emulsion was adjusted to 0.
7.0 ml of 1% chloroauric acid aqueous solution and 10 ml of 0.1% sodium thiosulfate were added, and chemical aging was carried out at 63 ° C. for 60 minutes. The thus-obtained three kinds of emulsions were coated on a triacetyl cellulose film support having an undercoat layer, in the coating amounts shown in Table 3 to provide the emulsion and the protective layer.

[0036]

[Table 3]

(1) Emulsion layer-Emulsion-Emulsions-1 to 8 (silver 2.1 × 10 ^-2 mol / m ² ) shown in Table 1-Coupler (1.5 × 10 ^-3 mol / m ^2). )

[0038]

Embedded image

Tricresyl phosphate (1.10 g / m ² ), gelatin (2.30 g / m ² ) (2) protective layer, 2,4-dichlorotriazine-6-hydroxy-s-triazine sodium salt ( 0.08 g / m ² ) ・ Gelatin (1.80 g / m ² ).

These samples were left under conditions of 40 ° C. and 70% relative humidity for 14 hours, then exposed for sensitometry and subjected to the following color development processing. The density of the treated sample was measured with a green filter. Table 3 shows the obtained photographic performance results. The developing treatment used here was performed at 38 ° C. under the following conditions. 1. Color development: 2 minutes 45 seconds 2. Bleaching ... 6 minutes 30 seconds 3. Washing with water ... 3 minutes 15 seconds 4. Fixed arrival ... 6 minutes and 30 seconds 5. Washing with water ... 3 minutes 15 seconds 6. Stable ... 3 minutes 15 seconds

The treatment liquid composition used in each step is as follows. Color developer Sodium nitrilotriacetate 1.0 g Sodium sulfite 4.0 g Sodium carbonate 30.0 g Potassium bromide 1.4 g Hydroxylamine sulfate 2.4 g 4- (N-ethyl-N-β-hydroxyethylamino) -2 -Methyl-aniline sulfate 4.5 g Water was added to 1 liter Bleach Ammonium bromide 160.0 g Ammonia water (28%) 25.0 ml Ethylenediamine-sodium tetraacetate iron salt 130 g Glacial acetic acid 14 ml Water was added 1 liter

Fixer Sodium tetrapolyphosphate 2.0 g Sodium sulfite 4.0 g Ammonium thiosulfate (70%) 175.0 ml Sodium bisulfite 4.6 g Water was added to 1 liter Stabilizer Formalin 8.0 ml Water was added to 1 liter Table 4 shows the results of measurement of sensitometry and granularity.
As is clear from Table 4, the emulsion of the present invention has excellent gradation and excellent graininess.

[0043]

[Table 4]

[Brief description of drawings]

FIG. 1 shows a calibration curve for measuring the silver iodide content of silver iodobromide grains by an X-ray microanalyzer, where the horizontal axis represents the silver iodide content and the vertical axis represents the characteristic X-rays of iodine and silver. It represents the intensity ratio.

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[Procedure amendment]

[Submission date] January 25, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

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[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 2

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[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

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[Correction contents]

[0004]

These objects of the present invention are as follows: (1) A tetradecahedron in which 95% or more of grains are cubic crystal grains or a grain surface area of which exceeds 50% is (200) faces. A silver halide emulsion which is a silver iodobromide grain composed of crystal grains, wherein the average silver iodide content of the silver iodobromide grain is 5 mol% to 10 mol% and the iodide of each grain is iodide. A photosensitive silver halide emulsion having a relative standard deviation of silver content of 20% or less, and (2) 95%
A silver halide emulsion in which the grains of the above number are cubic crystal grains or silver iodobromide grains composed of tetradecahedral crystal grains having a grain surface area exceeding 50% of (200) planes. Process for producing a photosensitive silver halide emulsion in which the average silver iodide content of silver iodide grains is 5 mol% to 10 mol% and the relative standard deviation of the silver iodide content of individual grains is 20% or less In the presence of a silver halide solvent in a gelatin aqueous solution, a water-soluble silver salt aqueous solution and a water-soluble alkali metal halide aqueous solution are added to obtain a pAg of 7.0 to 8.3.
And a method for producing a light-sensitive silver halide emulsion, characterized in that they are added at the same time while being kept constant within the range.

Claims (2)

[Claims] 1. A silver iodobromide emulsion consisting essentially of cubic or tetradecahedral crystal grains mainly composed of (200) faces, wherein the silver iodobromide grains have an average silver iodide content of 5 or less. A light-sensitive silver halide emulsion characterized in that it is at least mol% and the relative standard deviation of the silver iodide content of individual grains is at most 20%. 2. A silver iodobromide emulsion essentially consisting of cubic or tetradecahedral crystal grains mainly composed of (200) planes, wherein the silver iodobromide grains have an average silver iodide content of 5 mol. % And the relative standard deviation of the silver iodide content of each grain is 20
In the method for producing a light-sensitive silver halide emulsion having a concentration of not more than 0.1%, an aqueous solution of a water-soluble silver salt and an aqueous solution of a water-soluble alkali metal halide are added to a gelatin aqueous solution in the presence of a silver halide solvent to obtain pAg 7.0 A method for producing a photosensitive silver halide emulsion, characterized in that the addition is carried out at the same time while keeping the content constant within the range of 8.3 to 8.3.