JP3049647B2 - Production method of silver halide photographic emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silver halide emulsion for photographic use, and more particularly, to a method for producing a silver halide emulsion having high sensitivity, high transitivity, and excellent storage and processing properties. is there.

[0002]

2. Description of the Related Art In recent years, photographic light-sensitive materials have been required to have various performances. However, as performance required for photographic light-sensitive materials and print light-sensitive materials, improvements in sensitivity and storage stability are always required. There is an issue. On the other hand, there has been a high demand for low replenishment of a processing solution without knowing that the demand for simplification and speeding up of the development processing in recent years will remain. However, in many cases, the enhancement of the sensitivity of the photosensitive material, the improvement of the storage stability of the photosensitive material, the reduction of the processing solution, and the increase of the processing speed are contradictory. For example, increasing the iodine content of a silver halide emulsion is one of the most well-known techniques as a typical sensitization technique. This is as described in various documents and patents. As for the knowledge of sensitization by iodine, see, for example, JP-A-48-51627,
193137 and JP-A-3-121142. In addition, the use of silver iodide on the surface of silver halide grains not only enhances the absorption of spectral sensitizing dyes to enhance sensitization, but also suppresses the desorption of the dyes at high temperatures and high humidity, thereby improving the storage stability. Bring. These publications disclose that the conversion of the grain surface to iodine (halogen conversion) enhances the dye adsorption and controls the formation site of the chemical sensitizing nucleus by the site direct function of the dye. −3053
43, as is well known in the art, as represented by JP-A-3-121442. However, such use of silver iodide not only causes deterioration in pressure properties (pressure blackening), but also causes fogging due to accumulation of iodide ions in the processing solution, poor fixing, and residual color of the dye. It was not preferable in terms of processability and low replenishment resistance. The complications of increasing the silver iodide content in silver halide with respect to processing properties and the like are described in detail in, for example, the following documents. JP-A-2-225637, 3-12
No. 1789, No. 3-135227, No. 3-10363
No. 9.

[0003] The present inventors have studied how to improve sensitization and enhance dye adsorption with such a small amount of silver iodide. The host grains (base grains) are ripened at a pAg of 8.3 or less, and the grain surfaces are converted (halogen-converted) with silver iodide.
It has been found that sensitization and enhancement of dye adsorption can be achieved. This makes it possible to achieve both rapid and low replenishment suitability and excellent photographic performance. With respect to the technique of adding finely divided silver halide which is hardly soluble in host grains, see, for example, JP-A-3-238444 and JP-A-3-121442.
Etc. are described in detail. However, the technology disclosed in the present invention for forming an extremely thin high iodine layer on the surface of particles by dissolving high iodine fine particles in a low pAg atmosphere is completely novel. Further, the emulsion having the high iodine surface layer formed by such a method is subjected to chemical sensitization (sensitization with gold and chalcogenide) after the addition of the spectral sensitizing dye to obtain the best photographic performance. I understood. This is completely new.

[0004]

A light-sensitive material having high sensitivity, high transitivity, and excellent storage stability, but having little processing dependency and low liquid fatigue during running, and a silver halide emulsion constituting the same. The purpose is to provide.

[0005]

Means for Solving the Problems The present inventors have achieved the above object by the following method. (1) After completion of silver halide grain formation , addition of spectral sensitizing dye
Silver halide fine grains containing silver iodide are added in an atmosphere having a pAg of 8.3 or less before the addition. ( 2 ) The method for producing a silver halide emulsion according to (1), wherein in (1), the spectral sensitizing dye is added before the chemical sensitizer is added. ( 3 ) The method for producing a silver halide emulsion according to (1) or (2), wherein the silver halide fine grains containing silver iodide are silver iodide fine grains. ( 4 ) The silver halide fine particles of (1) are added to
70% of the total projected area of the host grains forming the iodine layer
As described above, it was found that particularly excellent photographic performance can be obtained when the tabular grains have an average aspect ratio of 3 or more. ( 5 ) In any one of (1) to (4), excellent when the amount of silver iodide added by silver halide fine grains is 1 mol% or less based on all silver halide including host grains. It was found that photographic performance was obtained. ( 7 ) A photographic light-sensitive material containing the silver halide emulsion prepared in any one of the above (1) to (5) was produced to achieve the above object.

Next, the spectral sensitizing dye preferably used in the present invention will be described in detail. It is essential that the step of chemical sensitization (chemical ripening) in the method for producing the emulsion of the present invention includes a step performed in the presence of a spectral sensitizing dye until the end of post-ripening. However, the case where the step of chemical sensitization is terminated by adding a spectral sensitizing dye is also included in the above-mentioned step. The dye addition in the present invention is used for the purpose of causing the sensitizing dye to act as a control agent for the formation of a photosensitive nucleus during chemical sensitization. In addition, such a dye addition method results in adsorption of the dye to the particles at a high temperature of 50 ° C. or higher, and is used for the purpose of promoting the enhancement of the adsorption. The term “end of post-ripening” as referred to in the present invention refers to the stage at which the progress of chemical sensitization has stopped. The chemical sensitization in the presence of the spectral sensitizing dye in the present invention can be carried out at any stage in the preparation of an emulsion which is known to be useful before chemical ripening is completed. U.S. Pat. Nos. 3,628,960 and 4,225,666
The spectral sensitization can be carried out simultaneously with the chemical sensitization, as taught in US Pat. You can also. US Patent No. 4,225,6
As taught in U.S. Pat. No. 66, it is also possible for some of the spectral sensitizing dyes to be present in a step prior to the completion of chemical sensitization and the remainder to be introduced after chemical sensitization. That is, the spectral sensitizing dye may be added at any time before the chemical sensitization, during the chemical sensitization, or immediately before the end of the chemical sensitization. The spectral sensitizing dye used in the present invention can be used in combination with a nitrogen-containing heterocyclic compound represented by the following general formula described in JP-A-62-89952. General formula

[0007]

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Wherein R ¹ is at least one —COO
M or -SO ₂ M substituted aliphatic group, an aromatic group or a heterocyclic group, M represents a hydrogen atom, an alkali metal atom, a quaternary ammonium or quaternary phosphonium. ) The amount used is 1 × per mole of silver halide.
10 ^-5 to 1 × 10 ^-2 mol, preferably 1 × 10 ^-4.
１1 × 10 ⁻³ mol.

The spectral sensitizing dye that can be used in the present invention can be selected from conventional methine dyes and is not particularly limited. The dyes used in the present invention include polymethine dyes including cyanines, merocyanines, complex cyanines and complex merocyanines (i.e., tree, tetra and poly-nuclear cyanines and merocyanines) oxonol, hemioxonol, styryl, merostyryl and streptocyanin. included. Cyanine spectral sensitizing dyes include quinolinium, pyridinium, isoquinolinium,
3H-indolium, benz [e] indolium, oxazolium, oxazolinium, thiazolium, thiazolinium, selenazolium, selenazolinium, imidazolium, imidazolinium, benzothiazolinium,
Derived from benzothiazolium, benzoselenazolium, benzimidazolium, naphthoxazolium, naphthothiazolium, naphthoselenazolium, thiazolinium, dihydronaphthothiazolium, sodium and imidazopyrazinium quaternary salts And two basic heterocyclic nuclei joined by a methine bond. Merocyanine spectral sensitizing dyes include barbituric acid, 2-thiobarbituric acid, rhodanine, hydantoin, 2-thiohydantoin, 4-thiohydantoin, and 2-pyrazolin-
5-one, 2-isoxazolin-5-one, indane-1,3-dione, cyclohexane-1,3-dione,
1,3-dioxane-4,6-dione, pyrazoline-
Acidic nuclei such as those derived from 3,5-dione, pentane-2,4-dione, alkylsulfonylacetonitrile, malononitrile, isoquinolin-4-one and chroman-2,4-dione and basic heterocycles of cyanine dye type Includes those bonded to the nucleus by methine bonds. Examples of blue-sensitive sensitizing dyes include, for example, US Pat. No. 2,493,748, JP-B-46-30023, US Pat.
3976492; JP-A-58-91444;
-289,341 and JP-A-59-55,426 can be used. As a green-sensitive sensitizing dye, for example,
US Pat. No. 3,506,443, JP-B-47-25379, JP-B-43-4936, JP-A-62-139,522, JP-A-61-156,046, JP-A-60-128,43.
3, those described in JP-B-49-4650 can be used.
Examples of red-sensitive sensitizing dyes include, for example, Japanese Patent Publication No. Sho 43-4
933, JP-B-46-10,473, JP-B-45-3
2,741, JP-A-59-135,461, JP-A-59-135
-214,030, JP-A-61-282,831, JP-A-59-166,955, JP-A-59-77,443,
U.S. Pat. No. 4,326,023 can be used.
For the color sensitization during or in combination with the chemical sensitization in the present invention, various supersensitization techniques can be used. Examples of useful dye combinations, including supersensitizing dye combinations, are described in U.S. Patents 3,506,443 and 3,672,898.
No. Examples of supersensitized combinations of spectral sensitizing dyes and non-light absorbing additives include US Pat.
U.S. Pat. No. 2,933,390 discloses the use of thiocyanates in the process of spectral sensitization as indicated in US Pat.
US Pat. No. 3,457,078 using bis-triazinylaminostilbene as shown in US Pat. Using a mercapto-substituted heterocyclic compound as indicated, British Patent 1,413,8
Iodide can be used as indicated in No. 26.

As a method for adding a sensitizing dye during the production process of the emulsion of the present invention, various methods conventionally proposed can be applied. For example, U.S. Pat.
The method may be carried out by dissolving the sensitizing dye in a volatile organic solvent, dispersing the solution in a hydrophilic colloid, and adding the dispersion to an emulsion as described in JP-A-9,987. Furthermore, the sensitizing dyes of the present invention can be dissolved individually in the same or different solvents, and these solutions can be mixed or added separately before adding to the emulsion. In the present invention, when the sensitizing dye is added to the silver halide emulsion, the amount of addition is from 1 × 10 ^-5 mol to 2.times.
5 × 10 ⁻³ mol is preferred, more preferably 1.0 × 1
0 ^-4 mol to 1.0 × 10 ^-3 mol. The sensitizing dye can be used in combination with another sensitizing dye or a supersensitizer. In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

In the present invention, it is extremely important to perform chemical sensitization represented by chalcogen sensitization and gold sensitization.
The location of chemical sensitization depends on the composition, structure, and shape of the emulsion grains, and on the intended use in which the emulsion is used. There is a case where a chemical sensitizing nucleus is embedded in the inside of a grain, a case where the chemical sensitizing nucleus is embedded in a position shallow from the grain surface, or a case where a chemical sensitizing nucleus is formed on the surface. The effect of the present invention is effective in any case, but is particularly preferable when a chemical sensitizing nucleus is formed near the surface. That is, the surface latent image type emulsion is more effective than the internal latent image type emulsion.

Chemical sensitization is described in TH James,
The Photographic Process, 4th Edition, Macmillan, 1977, (THJames, The Theory of the
Photographic Process, 4th ed, Macmillan, 197
7) It can be carried out using active gelatin as described on pages 67-76, and can also be performed by Research Disclosure 120, April 1974, 12008; Research Disclosure 34, June 1975, 1
3452, U.S. Pat. Nos. 2,642,361 and 3,2
97,446, 3,772,031, 3,85
7,711, 3,901,714, 4,26
No. 6,018 and 3,904,415, and pA as described in GB 1,315,775.
The reaction can be carried out using sulfur, selenium, tellurium, gold, platinum palladium, iridium or a combination of these sensitizers at g 5 to 10, pH 5 to 8 and a temperature of 30 to 80 ° C.

As the gold sensitizer used in the present invention, a gold complex salt (for example, see US Pat. No. 2,399,083) can be particularly preferably used. Of these,
Potassium chloroaurate, rate, potassium aurithiocyanate, aurilic trichloride, sodium aurithiosulfate, and 2-aurosulfobenzothiazole methchloride are particularly preferred. The content of the gold sensitizer in the silver halide grain phase is preferably 10 ^-4 to 10 ^-3 mol, particularly preferably 10 ^-2 to 10 ^-4 mol, per mol of silver halide.

In the present invention, not only gold sensitization but also sulfur
It is preferable to use chalcogen sensitization such as yellow sensitization together
No. As the sulfur sensitizer to be used, for example, thiosulfate, titanium
Ureas, thiazoles, rhodanines, and other compounds
(Specific examples; U.S. Pat. Nos. 1,574,944,
No. 2,410,689, No. 2,278,947,
No. 2,728,668, No. 3,656,955
No. 4,030,928, 4,067,74
0), and among these, thiosulfate and thiosulfate
Oureas and rhodanines are particularly preferred. Calco
The amount of the gen sensitizer depends on the particle size, the temperature of chemical sensitization, pA
The optimal amount can be selected according to conditions such as g, pH, etc.
You. 10 per mole of silver halide^-7-10 ^-3Mole, preferred
Or 5 × 10^-7-10^-FourMole, more preferably 5 ×
10^-7-10^-FiveUse moles.

The temperature of the chemical sensitization is in the range of 30 ° C. to 90 ° C., the pAg is 5 or more and 10 or less, and the pH is 4 or more and can be appropriately selected. In the present invention, a sensitization method using a metal such as iridium, platinum, rhodium, and palladium (for example, U.S. Pat. Nos. 2,448,060, 2,566,245, and 2,566,263), and a selenium compound The selenium sensitization method used can also be used in combination. Chemical sensitization can also be performed in the presence of a chemical sensitization aid. Chemical sensitizing aids used include azaindene, azapyridazine, azapyrimidine,
Compounds known to suppress fog and increase sensitivity during chemical sensitization are used. Examples of chemical sensitization aid modifiers are described in U.S. Pat.
Nos. 411,914 and 3,554,757;
No. 8-126526 and the above-mentioned "Photographic Emulsion Chemistry" by Duffin, pp. 138-143. However, chemical sensitization in the present invention is to be distinguished from reduction sensitization.

Regarding silver halide fine grains containing silver iodide The term "silver halide fine grains containing silver iodide" as used in the present invention means those having a silver iodide content of 10% or more, preferably 20% or more. And most preferably 100% silver iodide. In addition, the size refers to a particle having an average equivalent sphere diameter of 0.1 μm or less because it is necessary to grow the layer on the surface of the substrate particle by dissolution. Preferably, the thickness is 0.05 μm or less. The average equivalent sphere diameter mentioned here is the average diameter when the particles are viewed as a sphere.

In the method of the present invention, excellent photographic performance can be obtained with a small amount of silver iodide using fine grains containing silver iodide because a high iodine surface layer can be efficiently formed on the grain surface. It is. This can be clarified by a surface analysis technique called ISS (slow ion scattering spectroscopy) as shown in Example 2. The ISS method is described in detail in, for example, Masakazu Aono et al., Maruzen, p. 162, Handbook for Surface Properties, but when sputtered by argon plasma or the like in a vacuum, ionized atoms scattered from the sample surface and come out. (Or molecules) is analyzed by a mass spectrometer to perform elemental analysis of the sample pole surface (several to several tens of degrees).

The emulsion used in the present invention is not particularly limited, but the emulsion serving as a substrate may be AgBr, AgBrI, Ag
Cl and AgBrCl are preferred, and in particular AgBr and AgB
rCl and AgCl are preferred. The content of silver iodide used is preferably 1 mol% or less, particularly preferably 0.5 mol% or less in the whole grains.

Further, the fine grains containing silver iodide of the present invention are added at any time before the addition of the spectral sensitizing dye and after the formation of the grains, before the desalting and washing step and before the end of chemical sensitization. good. However, the pAg at the time of addition is preferably 8.3 or less, more preferably 8.1, and even more preferably 7.8 or less.

Next, tabular silver halide grains preferably used in the present invention will be described. The tabular silver halide grains of the present invention preferably have a diameter / thickness ratio of 3 or more, more preferably 5 or more and 100 or less, more preferably 5 or more and 50 or less (particularly preferably 7 or more and 20 or less). It is. Here, the diameter of a silver halide grain refers to the diameter of a circle having an area equal to the projected area of the grain. In the present invention, the diameter of the tabular silver halide grains is preferably from 0.5 to
It is 10 μ, more preferably 0.5 to 5.0 μ, and particularly preferably 1.0 to 4.0 μ. Generally, tabular silver halide grains are tabular having two parallel planes. Therefore, the "thickness" in the present invention is defined as the distance between the two parallel planes constituting the tabular silver halide grains. Is represented. The halogen composition of the tabular silver halide grains is preferably silver bromide and silver iodobromide, silver chloride, silver chlorobromide, silver chloroiodide, and silver chloroiodobromide. Is preferably 0 to 1.0 mol%. Next, a method for producing tabular silver halide grains will be described. The tabular silver halide grains can be produced by appropriately combining methods known in the art. For example, in an atmosphere having a relatively high pAg value of pBr of 1.3 or less, tabular grains form seed crystals in which 40% or more exist by weight, and seeds are added while simultaneously adding silver and a halogen solution while maintaining the same pBr value. Obtained by growing crystals. It is desirable to add a silver and halogen solution so that no new crystal nuclei are generated during the grain growth process. The size of the tabular silver halide grains can be adjusted by controlling the temperature, the type and amount and selection of the solvent, and the addition rate of the silver salt and halide used during grain growth. In the production of the tabular silver halide grains of the present invention, the shape of grain size grains (diameter / thickness ratio, etc.), grain size distribution, and grain growth rate can be controlled by using a silver halide solvent as necessary. . The amount of the solvent used is 10 ^{−3 to} 1.0 of the reaction solution.
% By weight, especially 10 ^-2 to 10 ^-1 % by weight.

For example, as the amount of the solvent used increases, the particle size distribution becomes monodispersed, and the growth rate can be increased. On the other hand, there is also a tendency that the thickness of the particles increases with the amount of the solvent used. Silver halide solvents often used include ammonia, thioethers and thioureas. Regarding thioethers, U.S. Pat. Nos. 3,271,157, 3,790,387 and 3,574,628 can be referred to.
In the production of the tabular silver halide grains of the present invention, the addition rate, amount and concentration of a silver salt solution (for example, an aqueous AgNO ₃ solution) and a halide solution (for example, an aqueous KBr solution) are added to accelerate the grain growth. The method of raising is preferably used. Regarding these methods, for example, British Patent No. 1,335,925, US Pat. No. 3,672,900
No. 3,650,757, No. 4,242,44
No. 5, JP-A Nos. 55-142329 and 55-1581
No. 24 etc. can be referred to.

In the layer containing the tabular silver halide grains of the present invention, the tabular grains having an aspect ratio of 3 or more have a projected area ratio of 70% or more to all the silver halide grains in the layer. In particular, it is preferably present at 80% or more. The layer containing the tabular silver halide grains has a thickness of 0.3 to 5.0.
μ, particularly preferably 0.5 to 3.0 μ. Other constitutions of the layer containing the tabular silver halide grains of the present invention, for example, a binder, a curing agent, an antifoggant, a silver halide stabilizer, a surfactant, a spectral sensitizing dye, a dye,
There is no particular limitation on the ultraviolet absorber, chemical sensitizer, etc., for example, Research Disclosure 176, 22-28.
Page (December 1978) can be referred to.

The emulsion layer of the silver halide photographic light-sensitive material of the present invention may contain ordinary silver halide grains in addition to tabular silver halide grains. These are P.Gl
afkides, Chimie et Physique Photographique (Paul
Montel 1967), Photograp by GFDuffin
hic Emulsion Chemistry (The Focal Press 1966
Year), Making and Coating Phot by VLZelikman et al
ographic Emulsion (The Focal Press, 1964)
It can be prepared using the method described in, for example.
That is, any of an acidic method, a neutral method, an ammonium method and the like may be used, and a method of reacting a soluble silver salt and a soluble halide may be any of a one-side mixing method, a double-mixing method, a combination thereof and the like. . A method of forming grains in the presence of excess silver ions (a so-called reverse mixing method) can also be used. As one type of the double jet method, a method in which pAg in a liquid phase in which silver halide is formed is kept constant, that is, a so-called controlled double jet method can be used.

The silver halide emulsion produced by the production method of the present invention can be used, for example, for color photographic materials for photography (color negative film, color reversal film). Further, it can be used for a printed photosensitive material. or,
It can be used as a photosensitive material for X-rays, a photosensitive material for black photography, a photosensitive material for plate making, photographic paper, and the like.

There are no particular restrictions on the various additives and the like used in the photographic light-sensitive material of the present invention, and for example, those described in the following applicable places can be used. Item 1) Silver halide emulsion and 6 from the lower right column on page 8 of JP-A-2-68539, from its production line, from line 12 on page 10, upper right column, line 12, 3-24537 The gazette, page 2, lower right column, line 10 to page 6, upper right column, line 1, page 10, upper left column, line 16 to page 11, lower left column, line 19, Japanese Patent Application No. 2-225637. 2) Chemical sensitization method JP-A-2-68539, page 10, right upper column, line 13 to upper left column, line 16, Japanese Patent Application No. 3-105035. 3) Antifoggants and stabilizers JP-A-2-68539, page 10, lower left column, line 17 to page 11, page 11 upper left column, line 7 and page 3, lower left column, line 2 to page 4, lower left column . 4) Color tone improver From page 7, lower left column, line 7 to page 10, lower left column, line 20 of JP-A-62-276538, and from page 15, lower left column, line 15 of page 6 of JP-A-3-94249. Page 11, right upper column, line 19. 5) Spectral sensitizing dyes JP-A-2-68539, page 4, lower right column, line 4 to page 8, lower right column. 6) Surfactant JP-A-2-68539, page 11, upper left column, line 14, antistatic agent, page 12 upper left column, line 9; 7) Matting agent, slip agent JP-A-2-68539, page 12, upper left column, line 10 Plasticizer, line 10 in the upper right column, and page 14, line 10 in the lower left column, line 1 in the lower right column, line 1. 8) Hydrophilic colloid From page 11, upper right column, line 11 to lower left column, line 16 of JP-A-2-68539. 9) Hardener From page 17, lower left column, line 17 to page 13, upper right column, line 6 of JP-A-2-68539. 10) Support: Lines 7 to 20 in the upper right column on page 13, JP-A-2-68539. 11) Crossover JP-A-2-264944, page 4, upper right column, line 20, upper right column, page 14 from the cutting method. 12) Dyes and mordants JP-A-2-68539, page 13, lower left column, line 1 to page 14, lower left column, line 9. No. 3-24537, page 14, lower left column to page 16, lower right column. 13) Polyhydroxyl JP-A-3-39948, page 11, upper left column to benzenes, page 12, lower left column, EP Patent No. 452772A. 14) Layer structure JP-A-3-198041. 15) Developing method JP-A-2-103737, page 16, upper right column, line 7 to page 19, lower left column, line 15 and JP-A-2-115837, page 3, lower right column, line 5 Page 6, upper right column, line 10.

[0026]

【Example】

Example 1 Preparation of Tabular Particles 6.0 g of potassium bromide in 1 liter of water, average molecular weight 1
An aqueous solution containing 37 cc of an aqueous silver nitrate solution (4.00 g of silver nitrate) and 5.9 g of potassium bromide was added to a container kept at 55 ° C. while adding 7.0 g of low-molecular-weight gelatin of 15,000 and stirring.
8 cc was added in 37 seconds by the double jet method. Next, after adding 18.6 g of gelatin, the temperature was raised to 70 ° C., and 89 cc of an aqueous silver nitrate solution (9.80 g of silver nitrate) was added over 22 minutes. Here, 7 cc of a 25% aqueous ammonia solution was added, and the mixture was physically ripened at the same temperature for 10 minutes.
6.5 cc of a 0% acetic acid solution was added. Followed by silver nitrate 1
An aqueous solution of 53 g and an aqueous solution of potassium bromide were pAg8.5.
, And added over 35 minutes by the control double jet method. Next, 2N potassium thiocyanate solution 1
5 cc was added. After physical ripening at the same temperature for 5 minutes, the temperature was lowered to 35 ° C. Average projected area diameter 1.10
μm, thickness 0.165 μm, average aspect ratio 6.7,
Monodispersed pure silver bromide tabular grains having a diameter variation coefficient of 18.5% were obtained. Thereafter, soluble salts were removed by a sedimentation method.
The temperature was raised again to 40 ° C., and 30 g of gelatin, 2.35 g of phenoxyethanol and 0.8 g of sodium polystyrenesulfonate as a thickener were added, and the mixture was adjusted to pH 5.90 and pAg 8.00 with sodium hydroxide and silver nitrate solution. This emulsion was chemically sensitized while being kept at 56 ° C. while stirring. First, thiosulfonic acid compound-1 was added to 1 × 10
^-5 mol / mol Ag was added, and thiosulfonic acid compound-1 was added.

[0027]

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Further, 0.043 mg of thiourea dioxide was added and kept as it was for 22 minutes to perform reduction sensitization. Next, AgI fine grains having an average equivalent sphere diameter of 0.03 μm were added in an amount of 0.2 mol% per mol of silver halide. Next 4
-Hydroxy-6-methyl-1,3,3a, 7-tetrazaindene 20 mg and sensitizing dye

[0029]

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Was added. Further calcium chloride 0.8
3 g were added. Then 1.3mg of sodium thiosulfate
And 2.7 mg of selenium compound-1 and 2.6 mg of chloroauric acid and 90 mg of potassium thiocyanate.
After 0 minutes, it was cooled to 35 ° C. Selenium compound-1

[0031]

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Thus, the preparation of tabular grains T-1 was completed. Next, the order of addition of sensitizing dye, AgI fine particles, sodium thiosulfate and a selenium compound, chloroauric acid and potassium thiocyanate was changed as shown in Table 1 in exactly the same manner as in T-1. Each emulsion of T-9 was prepared.

[0033]

[Table 1] In T-8 and T-9, no AgI fine particles were added.

The interval at the time of adding these chemicals is 5
I took every minute.

Preparation of Coating Sample A coating sample was prepared by adding the following chemicals per mole of silver halide to form a coating solution. -Gelatin (including Ge1 in the emulsion) 108 g-Trimethylolpropane 9 g-Dextran (average molecular weight 39,000) 18.5 g-Sodium polystyrene sulfonate (average molecular weight 600,000) 1.8 g-Hardener 1,2 -Bis (vinylsulfonylacetamide) ethane Addition amount is adjusted so that the swelling ratio becomes 230%.

[0036]

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[0037]

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The surface protective layer was prepared and prepared so that each component had the following coating amount. Content of surface protective layer Coating amount ・ Gelatin 0.900 g / m ²・ Polymethyl methacrylate particles (average particle size 3.5 μm) 195 mg / m ²・ Sodium polyacrylate (average molecular weight 400,000) 0.023 ・ 4-hydroxy -6-methyl-1,3,3a, 7-tetrazaindene 0.015

[0039]

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Proxel (adjusted to pH 7.4 with NaOH) 0.005

In this way, test application samples 1 to 9 were prepared. Here, the support was adjusted as follows.

Preparation of Support (1) Preparation of Dye D-1 for Undercoat Layer The following dyes were ball-milled by the method described in JP-A-63-197943.

[0043]

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434 ml of water and 791 ml of a 6.7% aqueous solution of Triton X-200 surfactant (TX-200) were placed in a 2 liter ball mill. 20 g of the dye were added to this solution. Zirconium oxide (ZrO) beads 4
00 ml (2 mm diameter) was added and the contents were ground for 4 days. Thereafter, 160 g of 12.5% gelatin was added. After defoaming, the ZrO beads were removed by filtration. Observation of the obtained dye dispersion showed that the particle size of the pulverized dye had a wide field ranging from 0.05 to 1.15 μm in diameter, and the average particle size was 0.37 μm. Furthermore, dye particles having a size of 0.9 μm or more were removed by centrifugation. Thus, a dye dispersion D-1 was obtained. (2) Preparation of Support A corona discharge treatment was performed on a biaxially stretched 183 μm-thick polyethylene terephthalate film, and a first undercoating liquid having the following composition was applied so that the coating amount was 5.1 cc / m ^2. It was applied with a wire bar coater and dried at 175 ° C. for 1 minute. Next, a first undercoat layer was similarly provided on the opposite surface. The polyethylene terephthalate used contained a dye having the following structure at 0.04 wt%.

[0045]

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Butadiene-styrene copolymer latex solution (solid content 40% butadiene / styrene weight ratio = 31/69) 79cc 2,4-dichloro-6-hydroxy-s-triazine sodium salt 4% solution 20.5cc distillation Water 900.5cc

[0047]

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A second undercoating layer having the following composition was coated on the first undercoating layer on both sides by a wire bar coater method on both sides such that the coating amount was as described below. Coated and dried at ℃.・ Gelatin 160 mg / m ²・ Dye dispersion D-1 (26 mg / m ² as a solid dye)

[0049]

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Matting agent Polymethyl methacrylate having an average particle size of 2.5 μm 2.5 g / m ²

Preparation of photographic material The above emulsion layer and surface protective layer were coated on both sides of the prepared support by a simultaneous extrusion method. The amount of silver applied per side was 1.75 g / m ² . The amount of gelatin applied and the swelling ratio determined by the freeze-drying method using liquid nitrogen were adjusted by the amount of gelatin added to the emulsion layer and the amount of hardener. (Processing) Automatic developing machine: The drive speed and gears of the FPM-9000 manufactured by Fuji Film Co., Ltd. were modified to increase the transport speed. <Development liquid concentrate> 56.6 g of potassium hydroxide 200 g of sodium sulfite 200 g 6.7 g of diethylenetriaminepentaacetic acid 16.7 g of potassium carbonate 10 g of hydroquinone 83.3 g 40 g of diethylene glycol 4-hydroxymethyl-4-methyl-1-phenyl-3- Pyrazolidone 22.0 g 5-methylbenzotriazole 2 g

[0052]

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Make up to 1 liter with water (adjust to pH 10.60). <Fixing solution concentrate> Ammonium thiosulfate 560 g Sodium sulfite 60 g Ethylenediaminetetraacetic acid disodium dihydrate 0.10 g Sodium hydroxide 24 g Water is adjusted to 1 liter (adjusted to pH 5.10 with acetic acid). When the developing process was started, each tank of the automatic developing machine was filled with the following processing solution. Developing tank: Starter 1 containing the above-mentioned developer concentrate 331, 667 ml of water, 2 g of potassium bromide and 1.8 g of acetic acid.
0 ml was added to bring the pH to 10.25. Fixing tank: 200 ml of fixer concentrate and 800 ml of water Processing speed: Dry to Dry 35 seconds Developing temperature: 35 ° C. Fixing temperature: 32 ° C. Drying temperature: 55 ° C. Replenishment amount: Developing solution 22 ml Coating samples 1 to 9 were exposed to green light for 1/20 second for 30 minutes / 10 × 12 inches Fixing solution and then processed by the above automatic developing machine. Sensitivity is Fo
The sensitivity is represented by the reciprocal of the amount of exposure that gives a density of g + 1.0.

[0054]

[Table 2]

It is clear that the emulsion prepared by the method of the present invention exhibits excellent photographic performance.

Example 2 Exactly the same as the tabular grain T-1 of Example 1, except that the amount of the AgI fine particles was changed, and that the KI solution was added instead of the AgI fine particles, and the pAg at the time of addition was added.
Emulsion particles T-10 to T-2
0 was created. Table 3 shows this state.

[0057]

[Table 3]

Using this emulsion, coating was carried out on the same support as in Example 1 in the same manner as in Example 1.
0 was created. Evaluation of photographic performance

After photographic materials 1 to 8 were exposed to green light for 1/20 second, development was carried out with developer (I) at 35 ° C. for 8 seconds and 24 seconds, followed by fixing, washing and drying, respectively. went. Developer (I) 1-phenyl-3-pyrazolidone 1.5 g hydroquinone 30 g 5-nitroindazole 0.25 g potassium bromide 3.0 g anhydrous sodium sulfite 50 g potassium hydroxide 30 g boric acid 5 g glutaraldehyde 10 g water was added, and the total amount was 1 Liters. (PH is 10.2
Adjusted to zero. )

The sensitivity is represented by the reciprocal of the exposure amount that gives a density of Fog + 1.0.
0 was set. The results are summarized in Table 4.

[0061]

[Table 4]

As described in the present invention, it was confirmed that excellent photographic performance was exhibited when conversion was performed by adding silver iodide fine particles in an atmosphere having a pAg of 8.3 or less.

Example 3 Preparation of Tabular Particles 6.0 g of potassium bromide in 1 liter of water, average molecular weight 1
An aqueous solution containing 37 cc of an aqueous silver nitrate solution (4.00 g of silver nitrate) and 5.9 g of potassium bromide was added to a container kept at 55 ° C. while adding 7.0 g of low-molecular-weight gelatin of 15,000 and stirring.
8 cc was added in 37 seconds by the double jet method. Next, 18.6 g of gelatin was added, and the temperature was raised to 65 ° C., and 89 cc of an aqueous silver nitrate solution (9.80 g of silver nitrate) was added over 22 minutes. Here, 20 cc of 25% ammonia aqueous solution
And then physically ripened at the same temperature for 10 minutes, followed by 1
18.6 cc of a 00% acetic acid solution was added. Subsequently, an aqueous solution of 153 g of silver nitrate and an aqueous solution of potassium bromide were added to pAg
While controlling at 8.0, it is 3 by the control double jet method.
Added over 5 minutes. Next, 15 cc of a 2N potassium thiocyanate solution was added. After physical ripening at the same temperature for 5 minutes, the temperature was lowered to 35 ° C. Monodispersed pure silver bromide tabular grains having an average projected area diameter of 0.70 μm, a thickness of 0.25 μm, an average aspect ratio of 2.8, and a diameter variation coefficient of 15.5% were obtained. Thereafter, soluble salts were removed by a sedimentation method. The temperature was raised again to 40 ° C., and 30 g of gelatin, 2.35 g of phenoxyethanol and 0.8 g of sodium polystyrenesulfonate as a thickener were added, and the mixture was adjusted to pH 5.90 and pAg 8.00 with sodium hydroxide and silver nitrate solution. The emulsion was subjected to the same chemical sensitization as in the emulsion T-1 of Examples 1 and 2 while being kept at 56 ° C. while stirring. In order to change the aspect ratio, the amount of 25% aqueous ammonia added before physical ripening, the 100% acetic acid solution after physical ripening, and the grain growth by the control double jet method with respect to the emulsion T-21 thus prepared. PAg at time
The pAg at the time of dispersion was changed by changing the temperature, the temperature and the amount of silver nitrate added during the dispersion.
2 to T-32 were produced.

[0064]

[Table 5]

This emulsion was coated in exactly the same manner as in Example 1, and the same sensitometric evaluation as in Example 2 was performed. Table 6 summarizes the results of the prepared coating samples as 21 to 32. As is evident from Table 6, in the emulsion of the present invention composed of tabular grains having an aspect ratio of more than 3, p
It was found that excellent photographic performance was exhibited when conversion was performed with fine grains containing silver iodide at Ag 8.3 or less. As shown in Table 6, coating sample 2 using emulsion T-21
The 24 second development sensitivity of No. 1 was set to 100.

[0066]

[Table 6]

Example 4 FIG. 1 shows the measurement results of the surface iodine amount of the emulsion grains T-17 and T-20 produced in Examples 1 and 2 by ISS (Ion Scattered Spectroscopy). It can be seen that the silver iodide content of the outermost surface layer can be increased in the case of adding silver iodide fine particles with a pAg of 8.3 or less, even though the added iodine amounts are equal. The emulsion particles used herein were obtained by removing substances adsorbed on the particle surface such as protective colloid (gelatin) and dyes in order to perform the measurement in a better condition.

[Brief description of the drawings]

FIG. 1 shows the measurement results of the grain surface iodine amount of the emulsion grains T-17 and T-20 prepared in Examples of the present invention by ion scattering spectroscopy. The horizontal axis represents the grain depth, and the vertical axis represents the ratio of iodine in all halogens.

[Explanation of symbols]

 1 Measurement result of sample T-17 2 Measurement result of sample T-20

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03C 1/015

Claims (5)

(57) [Claims] 1. After completion of silver halide grain formation , spectral sensitization
Before adding the dye, pulverize the silver halide fine grains containing silver iodide.
A method for producing a silver halide emulsion, wherein Ag is added in an atmosphere of 8.3 or less. 2. The method for producing a silver halide emulsion according to claim 1, wherein the addition of the spectral sensitizing dye is performed before the addition of the chemical sensitizer. 3. A process for producing a silver halide emulsion according to claim 1 or 2, wherein silver halide fine particles are silver iodide fine particles containing silver iodide. 4. The method according to claim 1, wherein 70% or more of the total projected area of the host grains to which the silver halide fine grains are added are tabular grains having an average aspect ratio of 3 or more. The addition amount of silver iodide by 5. particles, the silver halide emulsion according to claims 1 is 1 mol% or less relative to the total silver halide, including the host particles 4 any one Manufacturing method.