JPH02213836A - Silver halide photographic sensitive material and its production - Google Patents

Abstract

PURPOSE:To obtain an emulsion having high sensitivity and satisfactory graininess and hardly causing fog by adding previously prepd. fine silver halide particles to a reactor for nucleus formation and/or crystal growth for forming photosensitive silver halide particles contained in a silver halide emulsion layer. CONSTITUTION:Previously prepd. fine silver halide particles are added to a reactor for nucleus formation and/or crystal growth for forming photosensitive silver halide particles contained in a silver halide emulsion layer on a substrate, nucleus formation and/or crystal growth is carried out in the reactor to form photosensitive silver halide particles and these particles are sensitized by reduction. A photographic sensitive material using the resulting emulsion has high sensitivity and satisfactory graininess and hardly causes fog.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a silver halide photographic material useful in the field of photography and a method for producing the same. More specifically, the present invention relates to a silver halide photographic material with high sensitivity and fine graininess, and a method for producing the same.

[Prior Art] The basic properties required of silver halide emulsions for photography are high sensitivity, low fog, and fine grain.

In order to increase the sensitivity of an emulsion, (1) increase the number of photons absorbed by a single grain; (2) increase the efficiency with which photoelectrons generated by light absorption are converted into silver clusters (latent images); and (3) it is necessary to increase the development activity in order to effectively utilize the formed latent image.

1. A method for producing a silver halide photographic light-sensitive material, which is obtained by adding nucleation and/or crystal growth in the reaction vessel under conditions capable of sensitization.

9) Fine-sized silver halide grains are mixed with an aqueous solution of a water-soluble silver salt and a water-soluble halide in a mixer provided outside the reaction vessel in which nucleation and/or crystal growth of photosensitive silver halide grains occurs. Claim 7 or 7, wherein the photosensitive silver halide grains are formed by mixing an aqueous solution thereof, and are supplied into the reaction vessel immediately after formation to provide for nucleation and/or crystal growth of the photosensitive silver halide grains. 8. The method for producing a silver halide photographic material according to 8.

10) The method for producing a silver halide photographic material according to claim 8 or 9, characterized in that an oxidizing agent and/or an inhibitor are further present under conditions that allow reduction sensitization.

11) Claim 89 or 10, characterized in that the silver iodobromide has a silver iodide content of 3 mol% or more and 40 mol% or less.
Increasing the size of the silver halide photographic material described above increases the number of photons absorbed by one grain, but reduces the image quality.

Increasing the development activity is also an effective means for increasing the sensitivity, but in the case of parallel development such as color development, graininess generally deteriorates. In order to increase sensitivity without causing deterioration of graininess, it is most preferable to increase the efficiency of converting photoelectrons into latent images, that is, to increase quantum sensitivity. In order to increase quantum sensitivity, it is necessary to eliminate inefficient processes such as recombination and latent image dispersion as much as possible. It is known that reduction sensitization, which creates small silver nuclei with no development activity inside or on the surface of silver halide, is effective in preventing recombination.

In addition, James et al. have shown that when a type of reduction sensitization is performed in which a coated film of a gold/sulfur sensitized emulsion is vacuum degassed and then heat treated in a hydrogen gas atmosphere, it is We found that the sensitivity can be increased at a lower fog level compared to the conventional method. This sensitization method is well known as hydrogen sensitization, and is effective as a means for increasing sensitivity on a laboratory scale. Furthermore, hydrogen sensitization is actually used in the field of astrophotography.

Attempts at reduction sensitization have been considered for a long time.

Carroll U.S. Patent No. 2,48
7,850, a polyamine compound in Lowe et al. No. 2.512925, and a thiourea dioxide-based compound in British Patent No. 789.823 by Fallens et al. It was disclosed that it is useful as a sensitizing agent. Further C
o11ier (Korea) is a Photographer
ic 5science and engineering
g23, page 113 (1979) compares the properties of silver nuclei produced by various reduction sensitization methods.

She employed dimethylamine borane, stannous chloride, hydrazine, high pH aging, and low pAg aging. The method of reduction sensitization is further described in U.S. Patent No. 2.518.698,
It is also disclosed in No. 3,201,254, No. 3,411,917, No. 3.779777, and No. 3,930,867. Japanese Patent Publication Nos. 57-33572 and 58-14 regarding not only the selection of reduction sensitizers but also the method of using reducing agents.
No. 10, Japanese Unexamined Patent Publication No. 57179835, etc. Furthermore, regarding techniques for improving the storage stability of reduction-sensitized emulsions, the conventional method for preparing silver halide grains for photography is as follows: - For boat fishing, a silver salt aqueous solution and a halide salt are mixed in a colloid aqueous solution in a reaction vessel. Manufactured by reacting with an aqueous solution. Put a protective colloid such as gelatin and an aqueous halogen salt solution into a reaction container, and while stirring,
A single jet method in which an aqueous silver salt solution is added for a certain period of time, and a double jet method in which an aqueous gelatin solution is placed in a reaction vessel and an aqueous halogen salt solution and an aqueous silver salt solution are added for a certain period of time are known. Comparing the two methods, the double jet method yields silver halide grains with a narrower grain size distribution, and further allows the halide composition to be freely changed as the grains grow.

It is also known that the growth rate of silver halide grains varies greatly depending on the concentration of silver ions (halogen ions) in the reaction solution, the concentration of the silver halide solvent, the distance between grains, the grain size, etc. Especially the silver salt aqueous solution and the halogen salt solution added to the reaction vessel? Non-uniformity in the concentration of single ions or halogen ions created by the solution is explained in Japanese Patent Publications No. 57-82831 and No. 60-1784, depending on each concentration.
It is disclosed in No. 45. Despite many studies as described above, the increase in sensitivity has not been sufficient compared to hydrogen sensitization in which photosensitive materials are treated with hydrogen gas under vacuum.

This is reported in the Journal of Imagtng 5
science Vol. 29, p. 233 (1985)
It has been reported by Isar (Moyser) et al.

The conventional technology of reduction sensitization has not been sufficient to meet the recent demands for photographic materials with high sensitivity and high image quality. Hydrogen sensitization also has the disadvantage that if the photosensitive material is left in the air after hydrogen sensitization, the sensitizing effect is lost. Therefore, it is difficult to utilize this sensitization method in the case of photographic materials for which special equipment cannot be used.

The photosensitive silver halide grains used in high-sensitivity silver halide photographic materials are generally gold-sulfur sensitized on the surface of the grains, and the combination of reduction sensitization and gold sensitization is particularly Many studies have focused on reduction sensitization of the inside of the particles because of the formation of cavities.

The growth rates are different, resulting in non-uniformity in the resulting silver halide emulsion. For this purpose, it is necessary to quickly and uniformly mix the silver salt aqueous solution and the halogen salt aqueous solution supplied in the colloidal aqueous solution and cause them to react in order to make the concentration of silver ions or halogen ions uniform in the reaction vessel. However, in the conventional method of adding a halogen salt aqueous solution and a silver salt aqueous solution to the surface of a colloidal aqueous solution in a reaction vessel, areas with high concentrations of halogen ions and silver ions occur near the addition position of each reaction solution, resulting in a uniform It has been difficult to produce silver halide grains of high quality. Techniques disclosed in US Pat. No. 3,415,650, British Patent No. 1,323,464, and US Pat. No. 3,692,283 are known as methods for improving this local concentration deviation. These methods include a reaction vessel filled with an aqueous colloid solution, a hollow rotating mixer having a slit in the wall of a medium-thick cylinder (the inside is filled with an aqueous colloid solution, and more preferably the mixer is moved up and down by a disk). ) is installed so that its axis of rotation is vertical, and the halogen salt aqueous solution and silver salt aqueous solution are supplied from its upper and lower open ends into a mixer rotating at high speed through a supply pipe. (If there are upper and lower separation discs, the halogen salt aqueous solution and silver salt aqueous solution supplied to the upper and lower chambers are diluted by the colloid aqueous solution filled in each chamber, and the mixture is rapidly mixed and reacted. In this method, silver halide particles are grown by rapidly mixing them near the slit to cause a reaction), and then discharging silver halide particles produced by centrifugal force generated by the rotation of a mixer into an aqueous colloid solution in a reaction vessel.

On the other hand, Japanese Patent Publication No. 55-10545 discloses a technique for preventing uneven growth by improving local concentration deviation. In this method, an aqueous halogen salt solution and an aqueous silver salt solution are separately fed into a reactor filled with an aqueous colloid solution through supply pipes from the open lower end of a mixer into which the aqueous colloid solution is dripped. The reaction solution is rapidly stirred and mixed by a lower stirring blade (turbine blade) installed in the mixer to grow silver halide, and immediately a turbine blade installed above the stirring blade is stirred and mixed. ing.

However, with the manufacturing method and apparatus described so far, although it is possible to completely eliminate the local concentration non-uniformity of anti-ion and halogen in the reaction vessel, this concentration still remains within the mixer. Non-uniformity exists, particularly in the vicinity of the nozzles that supply the silver salt aqueous solution and the halogen salt aqueous solution, and in the lower part of the stirring blade and the stirring portion. Furthermore, the silver halide grains supplied to the mixer together with the protective colloid pass through a place with such a non-uniform concentration distribution, and what is especially important is that
Silver halide grains grow rapidly in these areas. In other words, in these manufacturing methods and devices, the concentration distribution exists within the mixer, and grain growth occurs rapidly within the mixer, allowing silver halide to grow uniformly without concentration distribution. That objective has not been achieved.

Furthermore, in order to eliminate the non-uniform distribution of the concentration of these negative ions and halide ions through more complete mixing, the reaction vessel and the mixer were made independent, and the silver halide grains grown by the upper stirring blade in the mixer were This is a technique in which the aqueous colloid solution in the reaction vessel is discharged from the opening of the upper mixer.

JP-A No. 57-92523 discloses a manufacturing method that similarly attempts to improve this non-uniformity of concentration.

In this method, a halogen salt aqueous solution and a silver salt aqueous solution are separately supplied from the open lower end of a reaction vessel filled with a colloidal aqueous solution to a mixer filled with the colloidal aqueous solution. Both reaction solutions were diluted with the aqueous colloid solution, and the reaction solution was rapidly stirred and mixed with the re-reaction solution using a lower stirring blade provided in the mixer, and silver halide particles immediately grew from the open part above the mixer. In the production method or apparatus in which the re-reacted liquid diluted with the colloidal aqueous solution is discharged into the colloid aqueous solution in the reaction vessel, the re-reacted liquid diluted with the colloid aqueous solution is discharged between the inner wall of the mixer and the agitating blade without passing through the gaps between the blades of the agitating blade. A silver salt aqueous solution and an aqueous silver salt solution are used in a production method and apparatus in which the re-reaction liquid is passed through a gap formed outwardly on the tip side of the blade, and the re-reaction liquid is rapidly and vigorously shear mixed in the gap to react and produce silver halide particles. Attempts have been made to grow silver halide grains by supplying and rapidly mixing an aqueous halide solution. For example, in JP-A-53-37414 and JP-B-48-21045, a protective colloid aqueous solution (containing silver halide particles) is circulated in the reaction vessel by a pump from the bottom of the reaction vessel, and in the middle of this circulation system, A manufacturing method and apparatus are disclosed in which a mixer is provided, a silver salt aqueous solution and a halogen aqueous solution are supplied to the mixer, and the rainwater solution is rapidly mixed in the mixer to grow silver halide grains.

Further, in US Pat. No. 3,897,935, a protective colloid aqueous solution (containing silver halide particles) is circulated in the reaction vessel by a pump from the bottom of the reaction vessel, and a halogen salt aqueous solution and a silver salt aqueous solution are pumped in the middle of this circulation system. A method of injecting is disclosed. JP-A-53-47397 discloses that a protective colloid aqueous solution (containing a silver halide emulsion) is circulated from the reaction vessel by a pump, and an alkali metal halide salt aqueous solution is first injected into the circulation system. A manufacturing method and apparatus are disclosed which are characterized in that the silver halide particles are dispersed until uniform, and then an aqueous silver salt solution is injected into the system and mixed to form silver halide grains.

[Problem to be solved by the invention]

It is true that with these methods, the flow rate of the aqueous solution in the reaction vessel flowing into the circulation system and the stirring efficiency of the mixer can be changed independently, and particle growth can be performed under conditions with a more uniform concentration distribution. However, in the end, the silver halide crystals sent from the reaction vessel together with the protective colloid aqueous solution rapidly grow at the injection port for the silver salt aqueous solution and the halogen salt aqueous solution. Therefore, as described above, it is impossible in principle to eliminate the concentration distribution near the mixing section or the injection port, and in other words, it is impossible to achieve the purpose of uniformly growing silver halide in a state where there is no concentration distribution.

As described above, in conventional methods for preparing photographic silver halide grains, non-uniformity in silver ion concentration in regions where grain growth occurs is unavoidable. Such non-uniformity in silver ion concentration not only causes non-uniformity in the reducing atmosphere in the reaction vessel, but also makes it difficult to add silver halide particles of that size when a reducing agent is used in combination. 1. A silver halide photographic material, characterized in that it is a photosensitive silver halide grain obtained by nucleation and/or crystal growth in said reaction vessel, and said grain is reduction sensitized.

(2) In a silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support, the light-sensitive silver halide grains contained in the silver halide emulsion layer are
Nucleation is carried out in the reaction vessel by adding previously prepared fine-sized silver halide grains under conditions capable of reduction sensitization into a reaction vessel in which nucleation and/or crystal growth of the grains is caused. and/or a silver halide photographic material characterized by being photosensitive silver halide grains obtained by crystal growth.

(3) Fine-sized silver halide grains are mixed with an aqueous solution of a water-soluble silver salt in a mixer provided outside a reaction vessel in which nucleation and/or crystal growth of photosensitive silver halide grains occurs. Formed by mixing an aqueous solution of halides,
Immediately after formation, the warpage causes non-uniformity in the silver nucleation reaction.

This is because the silver nucleation reaction is generally nAg"+ne→A
gn, but it is important to note that there is non-uniformity in silver ion concentration within the region where grain growth occurs, and the left side of the equation expressing the silver nucleation reaction above is the region where grain growth occurs. This is because it means different things depending on the location.

An object of the present invention is to provide an emulsion with high sensitivity and good graininess, and a method for producing an emulsion with high sensitivity and little fog.

The second object is to provide a photographic material with high sensitivity and good graininess, and a photographic material with high sensitivity and less fog.

[Means to solve the problem]

As a result of intensive studies, it has been found that the object of the present invention can be achieved by the following method.

(1) In a silver halide photographic material having at least one silver halide emulsion layer on a support, the light-sensitive silver halide grains contained in the silver halide emulsion layer are
Provided for nucleation and/or crystal growth of the photosensitive silver halide grains by supplying the photosensitive silver halide grains into a fine reaction vessel prepared in advance into a reaction vessel that causes nucleation and/or crystal growth of the grains. (1) or (2) above, characterized by
The silver halide photographic material described in .

(4) The silver halide photographic material as described in (2) or (3) above, characterized in that an oxidizing agent and/or an inhibitor is also present in the conditions that allow reduction sensitization.

(5) The silver halide photographic material as described in (2), (3) or (4) above, which is silver iodobromide having a silver iodide content of 3 mol % or more and 40 mol % or less.

(6) The silver halide photographic material as described in (2), (3) or (4) above, wherein the halogen composition is silver chlorobromide, silver chloroiodide or silver chloroiodobromide.

(7) In a method for producing a silver halide photographic material having at least one silver halide emulsion layer on a support, the photosensitive silver halide grains contained in the silver halide emulsion layer are Obtained by adding fine-sized silver halide grains prepared in advance to a reaction vessel in which nucleation and/or crystal growth is caused, and causing nucleation and/or crystal growth in the reaction vessel, and A method for producing a silver halide photographic material, characterized in that the grains are reduction sensitized.

(8) In a method for producing a silver halide photographic material having at least one silver halide emulsion layer on a support, the photosensitive silver halide grains contained in the silver halide emulsion layer are Nucleation and/or crystal growth is carried out in a reaction vessel by adding previously prepared fine-sized silver halide grains under conditions that allow reduction sensitization. A method for producing a silver halide photographic material, characterized in that it is obtained by crystal growth.

(9) Fine-sized silver halide grains are mixed with an aqueous solution of a water-soluble silver salt in a mixer provided outside a reaction vessel in which nucleation and/or crystal growth of photosensitive silver halide grains occurs. Formed by mixing an aqueous solution of halides,
Immediately after formation, it is supplied into the reaction vessel to serve for nucleation and/or crystal growth of the photosensitive silver halide grains. In the present invention, part or all of the above-mentioned particles are formed "under conditions that allow reduction sensitization" or "under conditions where reduction sensitization is possible"
The sensitization is carried out under conditions in which an oxidizing agent and/or an inhibitor are further present in addition to the conditions capable of reduction sensitization (hereinafter abbreviated as ``reduction sensitization''). Particle formation is "nucleation" and "growth"
"Growth" is further divided into "growth" in a narrow sense, in which silver halide grains for crystal growth are supplied from the outside to a reaction vessel where crystal growth occurs, and "growth" in a narrow sense, in which silver halide grains are supplied from the outside to a reaction vessel where crystal growth occurs. It can be divided into ``ripening,'' which progresses without supply. The reduction sensitization of the present invention may be carried out at any stage of the above particle formation or after the particle formation. Preferably, grains are grown by adding a fine-sized silver halide emulsion under conditions that allow reduction sensitization. When chemical sensitization is carried out in combination with gold sensitization, it is preferable to carry out reduction sensitization prior to chemical sensitization to avoid undesirable fogging, and more preferably reduction sensitization is carried out inside the particles. Production of the silver halide photographic material as described in (7) or (8) above, characterized in that reduced silver nuclei that cause fogging are reduced on the surface subjected to gold sensitization in combination with gold sensitization. Method.

00) The method for producing a silver halide photographic material as described in (8) or (9) above, characterized in that an oxidizing agent and/or an inhibitor is further present in the conditions capable of aggravating reduction.

CI+) (8) above, characterized in that it is silver iodobromide with a silver iodide content of 3 mol% or more and 40 mol% or less;
9) or the method for producing a silver halide photographic material according to 00).

02) The method for producing a silver halide photographic material as described in (8), (9) or 0ω above, wherein the halogen composition is silver chlorobromide, silver chloroiodide, or silver chloroiodobromide.

The present invention will be explained in detail below.

The manufacturing process of silver halide emulsions is broadly divided into steps such as grain formation, desalting, chemical sensitization, and coating. Particle formation is nucleation
It is divided into maturity, growth, etc. It is preferable that these steps are not uniformly performed, but that the order of the steps is reversed or that the steps are repeated.

The reduction sensitization of the present invention refers to a method in which a known reducing agent is added to a silver halide emulsion, and a method with a low pAg of 1 to 7 called silver ripening.
Either a method of growing or aging in an Ag atmosphere or a method of growing or aging in a high PL+ atmosphere of p) 18 to 11, which is called high pH aging, can be selected. Moreover, two or more methods can also be used together.

The method of adding a reduction sensitizer is a preferable method since the level of reduction aggravation can be finely adjusted.

As reduction sensitizers, stannous salts, amines and polyamines, hydrazine derivatives, formamidine sulfinic acid, ascorbic acid derivatives, hydroquinone derivatives, silane compounds, borane compounds, and the like are known. In the present invention, a compound selected from these known compounds can be used, or two or more kinds of compounds can be used in combination. Preferred compounds as reduction sensitizers are stannous chloride, thiourea dioxide, and dimethylamine borane. The amount of the reduction sensitizer to be added depends on the emulsion manufacturing conditions, so it is necessary to select the amount to be added, but a range of 10-' to 10-' mol per 1 mol of the halogenated compound is appropriate. Ascorbic acid derivatives are also used. It is a preferable compound as a reduction sensitizer, and the amount added in this case is suitably in the range of 5.times.10@-5 to 1.times.10@-' mol per mol of silver halide.

Reduction exacerbants include water, alcohols, glycols,
It is dissolved in a solvent such as ketones, esters, and amides and added during particle formation. It may be added in advance to the reaction vessel where particle formation occurs, or it may be added at an appropriate time during particle formation.

Furthermore, the solution of the reduction aggravator may be added in several portions or may be added continuously over a long period of time as particles are formed. The addition of a soluble silver salt solution or a soluble halide solution to adjust pHg for silver ripening, or an acid or alkali solution to adjust pi (to perform high pH ripening) can also be used with the above-mentioned reduction sensitizer solution. Similarly added.

In the reduction sensitization of the present invention, an oxidizing agent and/or inhibitor may be present together with the reducing agent for the purpose of adjusting the level of reduction sensitization. Examples include the (m-nitrohensyl)quinolinium chloride of the present invention. Further, compounds represented by the following general formulas (1) to (III) are also preferable as the oxidizing agent of the present invention.

[I) R-5O□S-gate (II) R-3O, S-R [l11) R302S Lm 5OzS
R2 [wherein R and R'SR" may be the same or different and each represents an aliphatic group, an aromatic group or a heterocyclic group, M represents a cation, L represents a divalent linking group, , m is 0 or 1.] Specific examples of compounds represented by the general formula T), (II) or (I[) are listed below, but the invention is not limited thereto.

(1-1) CH,SO,5Na (1-2) CzllsSO,5Na(1-3)
C11l, 5OzSK (14) C4t
lqSO2SLi (15) C6HI: +5Oz
The coexistence of an oxidizing agent and/or inhibitor during reduction sensitization with SNa(16) cd,,so□SNa is carried out mainly for two purposes. The first purpose is to replace the reducing agent added to carry out reduction sensitization at the necessary point in the particle formation process with the addition of the oxidizing agent and/or inhibitor at the point when reduction sensitization is no longer necessary. This means that it is inactivated by addition and does not generate unnecessary reduction-sensitizing nuclei.

The use of oxidizing agents and/or inhibitors according to the first purpose makes it possible to control the distribution of reduction sensitizing nuclei within the photosensitive silver halide grains. The second purpose of using an oxidizing agent and/or inhibitor is that the degree of reduction sensitization (depending on the size and number of reduced silver nuclei) is The goal is to help achieve optimal performance by adjusting the

The oxidizing agent used for the above purpose may be either an inorganic compound or an organic compound. Suitable examples are iodine, hexacyanoferrate(III) salts, promosuccinimide, quinone derivatives, periodates, persulfates, pentacyanonitrosyl ferrates, N(1-7) CH3(C1
h) 3CHCH2SO□S -NlI4tHs (18) CloHz+5OzSNa (19)
Cl21 (to ZSSO□SN (110) Cl
bHs, 5O2sNa(112)tCaH
g5(lzsNa(113) CHzOCLCHzS
OzS-Na(115) CI(z=cHcHzsO
zsNaCJaSOzS CHs CaH+7SOzSC)IzCH3 CJsS(hscHzcl(zCN C4H9SOZSC1(CH2CN CzHsSOzSCHzCthCtlzCthOl(C
2H, So□5CtltCtlzSOzCtlzCHz
SO□5C2H5C2HsS(lzscl[J (CH
2C1(2) NCH25O□5C21-1,.

CLCH20HCH2C1 (zOH Furthermore, the inhibitors used for the aforementioned purposes can be both inorganic and organic compounds, e.g.
Soluble halide salts used to adjust Hg, acids and alkalis used to adjust pH, and organic compounds used as so-called stabilizers in the art that can be adsorbed onto the silver halide grain surface (e.g. mercapto compounds, heterocyclic compounds) are preferably used.

However, when using compounds that can be adsorbed onto the surface of silver halide grains, it is preferable that these compounds have a small inhibitory power on the growth of silver halide grains.

It is also preferable to combine two or more of the methods using the oxidizing agent and/or inhibitor described above.

The amount of oxidizing agent or inhibitor, llAg, and pH selection vary depending on the type and amount of the coexisting reducing agent. It is selected depending on the oxidation-reduction potential of the reducing agent or oxidizing agent and the purpose of using the oxidizing agent, but for example, when adjusting the degree of reduction sensitization, the general formula (1), (11) or [■] It is preferable to add the oxidizing agent and/or inhibitor to the compound to be formed per mole of silver halide before setting the atmosphere (pAg, pH), but they may be added at the same time or in the reverse order.
What is important is that the reduction sensitization proceeds substantially in the presence of an oxidizing agent and/or an inhibitor. It may be added to the reaction vessel in advance or at an appropriate time during particle formation. As particles are formed, the oxidizing agent and/or inhibitor solution may be added in several portions or continuously over a long period of time.

As the oxidizing agent used for adjusting the degree of reduction sensitization, compounds of the above general formulas (1) to [111] are preferable,
More preferred is a compound of general formula (1). Adjustment of pAg by adding a soluble halogen salt and adjustment of pH by addition of an acid are also preferably used for the second purpose.

Furthermore, if it is possible to prevent the particle growth from being adversely affected, measures such as lowering the temperature of the reaction vessel in which the particle growth occurs may be used.

Next, a method for producing silver halide grains of the present invention will be described.

10-7 causing nucleation and/or crystal growth of the particles
It is preferable to add 10 −1 mol from 10 −1 mol. Another 10-
The amount added is preferably from 6 to 10-2, especially from 10-5 to 10-3 mol per mol Ag.

In order to add the above-mentioned oxidizing agent, inhibitor, I'Ag or a compound for adjusting pH during the manufacturing process of a photographic emulsion, a method commonly used for adding additives to a photographic emulsion can be applied. For example, water-soluble compounds should be prepared in an aqueous solution with an appropriate concentration, and compounds insoluble or sparingly soluble in water should be prepared in suitable organic solvents that are miscible with water, such as alcohols,
Among glycols, ketones, esters, amides, etc., they are dissolved in solvents that do not adversely affect photographic properties.
It can be added as a solution. When to add
It may be added at any stage during grain formation of the silver halide emulsion. In order to prevent unnecessary reduction sensitization, which is the first purpose of using an oxidizing agent and/or an inhibitor, they may be added at the point when reduction sensitization becomes unnecessary during particle formation. The second purpose of using an oxidizing agent and/or inhibitor is to adjust the degree of reduction sensitization by adding a reducing agent or by adding previously prepared fine-sized silver halide particles into the reductive reaction vessel. As a result, nucleation and/or crystal growth of silver halide grains is carried out in the reaction vessel.

That is, what is important in the present invention is that no silver salt aqueous solution or halogen salt aqueous solution is added to the reaction vessel for nucleation and/or grain growth, except for pAg tlj1 of the emulsion in the reaction vessel. Furthermore, the protective colloid aqueous solution (containing silver halide particles) in the reaction vessel should not be circulated to the mixer at all.

In the present invention, grain nuclei can be formed in the reaction vessel and crystals can be further grown by adding fine-sized silver halide grains prepared in advance into the reaction vessel. It is also possible to grow crystals by forming grain nuclei in the reaction vessel by a conventionally known method and adding the fine silver halide particles described above.

More specific methods for adding fine-sized silver halide grains include the following.

(1) Method of supplying silver halide fine particles from a mixer outside the reaction vessel In a mixer installed outside the reaction vessel where nucleation and/or crystal growth occurs, an aqueous solution of a water-soluble silver salt and a water-soluble halide Fine particles formed by mixing an aqueous solution of are immediately supplied into the reaction vessel to perform nucleation and/or crystal growth of silver halide core particles (hereinafter referred to as method A).

A system for such a particle formation method is shown below using FIG. 1 as an example.

In FIG. 1, a reaction vessel 1 first contains an aqueous protective colloid solution 2. In FIG. The protective colloid aqueous solution is stirred and mixed by a propeller 3 attached to a rotating shaft. Silver salt aqueous solution, halogen salt aqueous solution,
and a protective colloid aqueous solution are introduced in addition systems 4.5 and 6, respectively.

(At this time, the protective colloid aqueous solution may be added after being mixed with the halogen salt aqueous solution and/or the silver salt aqueous solution.) In a mixer, these solutions are quickly and rapidly dispersed into the intensive reaction container, and each individual Halogen ions and silver ions of the desired halide composition are released from the fine particles. The particles generated in the mixer are extremely fine, and the number of particles is very large, and from such a large number of particles, each individual ion and halogen ion (in the case of mixed crystal growth, the target halogen ion) ) is released and occurs throughout the protective colloid in the reaction vessel, allowing quite uniform nucleation and/or particle growth to occur. It is important that silver ions and halogen ions are never added to the reaction vessel as an aqueous solution except for pAg m1, and that the protective colloid solution in the reaction vessel is not circulated to the mixer. This method is completely different from conventional methods, and can produce surprising effects in the uniform growth of silver halide grains.

The solubility of the fine particles formed in the mixer is very high due to their fine particle size, and when added to the reaction vessel, they dissolve and become silver ions and halogen ions again, forming nuclei or leaving the reaction vessel. and immediately introduced into the reaction vessel 1 via system 8. FIG. 2 shows details of the mixer 7.

This mixer 7 is provided with a reaction chamber IO therein, and a stirring blade 9 attached to a rotating shaft 11 is provided in the reaction chamber 10. A silver salt aqueous solution, a halogen salt aqueous solution, and a protective colloid aqueous solution are added to the reaction chamber 10 through three inlets (4, 5, the other inlet is omitted from the drawing). Rotate the rotating shaft at high speed (1000
r, p, m or more, preferably 2000 r, p, m or more,
more preferably 3000 r, p, m or more),
The solution containing extremely fine particles produced by rapid and strong mixing is immediately discharged from the outlet 8 to the outside. In this way, the extremely fine particles generated by the reaction in the mixer are introduced into the reaction vessel, and because the particle size is fine,
It dissolves easily and becomes silver ions and halogen ions again, causing uniform grain growth. The halide composition of these extremely fine particles is made the same as the halide composition of the intended halogenated root particles. The ultrafine particles introduced into the reaction vessel are deposited on the particles already in the vessel due to stirring in the reaction vessel, causing particle growth.At this time, due to the high solubility of the fine particles, they form a so-called Ostwald formation in the mixer. Ripening occurs and the particle size increases. As the particle size increases, its solubility decreases, its dissolution in the reaction vessel slows down, the rate of particle growth decreases significantly, and in some cases it no longer dissolves and even grows It becomes the nucleus and causes growth.

In the present invention, this problem was solved by the following three techniques.

■ Immediately after forming the microparticles in the mixer, add them to the reaction vessel.

In the present invention, this Ostwald ripening can be prevented by providing a mixer very close to the reaction vessel and shortening the residence time of the additive liquid in the mixer, thereby immediately adding the generated fine particles to the reaction vessel. I tried not to. Specifically, the residence time t of the liquid added to the mixer is expressed as follows.

- a+b+c ■: Volume of reaction chamber of mixer (m2) a- Addition N of silver nitrate solution (m!2/1 layer 1n) b:
Amount of halogen salt solution added (mN/m1n) C: Amount of protective colloid solution added (mN/m1n) In the production method of the present invention, the time is 10 minutes or less, preferably 5 minutes or less, more preferably 1 minute or less, More preferably, it is 20 seconds or less.

The fine particles thus obtained in the mixer are immediately added to the reaction vessel without their particle size increasing.

■ Perform powerful and efficient stirring using a mixer.

James (T. H. James) The Theory of the Photographic Process p, p. 93,
“Along with Ostwald ripening, another form is agglomeration (c
oalescence). During coalescence ripening, crystals that were previously far apart come into direct contact and coalesce to form larger crystals, resulting in a sudden change in particle size. For both Ostwald ripening and coalescence ripening, addition to the vessel is done in the following manner, as well as after the completion of sedimentation.

(a) Inject the protective colloid aqueous solution alone into a mixer.

The concentration of the protective colloid is 0.2% by weight or more, preferably 0.
．． 5% by weight is good, and the flow rate is at least 20%, preferably at least 50%, more preferably 100% or more of the sum of the flow rates of the silver nitrate solution and the aqueous halide solution.

(b) Adding a protective colloid to the halogen salt aqueous solution.

The concentration of the protective colloid is at least 0.2% by weight, preferably at least 0.5% by weight.

(C) Adding a protective colloid to the silver nitrate aqueous solution.

The concentration of the protective colloid is 0.2% by weight or more, preferably 0.
．． It is 5% by weight or more. When gelatin is used, it is better to mix the silver nitrate solution and the protective colloid solution immediately before use, since gelatin silver is made from silver ions and gelatin, and silver colloid is produced by photolysis and thermal decomposition.

It also occurs during deposition. The coalescence ripening described herein is particularly likely to occur when the particle size is very small, and is particularly likely to occur if stirring is insufficient. In extreme cases, it may even create coarse, clumpy particles. In the present invention, as shown in Figure 2, a closed type mixer is used, so the stirring blade in the reaction chamber can be rotated at a high rotational speed, which was not possible with a conventional open type reaction vessel. (With the open type, if the stirring blades are rotated at high speeds, the liquid will be blown away by centrifugal force, which will also cause the problem of foaming, making it impractical.) Powerful and efficient stirring and mixing can be performed, and the above-mentioned coalescence Ripening can be prevented, and as a result, fine particles with extremely small particle sizes can be obtained. In the present invention, the rotation speed of the stirring blade is 1000 r, p, m or more, preferably 200 or, p, m or more, and more preferably 3000 r, p, m or more.
, p, m or more.

■ Injecting the protective colloid aqueous solution into the mixer The coalescence ripening described above can be significantly prevented by the protective colloid of the halogenated Sm(jlt) particles.In the present invention, the mixing of the protective colloid aqueous solution
These methods may be used alone or in combination, or three methods may be used at the same time.

2) Method of adding a pre-prepared fine-grain silver halide emulsion In the present invention, a pre-prepared fine-grain silver halide emulsion having fine-sized grains is added to a reaction vessel to perform nucleation and/or grain growth. A method can also be used (hereinafter referred to as "Method B"). As mentioned above, the smaller the grain size of the emulsion prepared in advance, the better. In this method as well, the pA of the emulsion in the reaction vessel in which nucleation and/or grain growth occurs is
Except for g adjustment, no aqueous solution of water-soluble silver salt or aqueous solution of water-soluble halide is added to the reaction vessel. This pre-prepared emulsion may be washed with water and/or solidified before being added to the reaction vessel.

Gelatin is preferably used as the protective colloid in the present invention.

The following polymer compounds other than gelatin having a protective colloid effect on silver halide grains used in the present invention are used.

(a) Polyacrylamide polymer A homopolymer of acrylamide, a copolymer of polyacrylamide and imidized polyacrylamide, a copolymer of acrylamide and methacrylamide.

(b) Aminopolymer (C) Polymer with thioether group US Patent 3
No. 615624, No. 3860428, No. 370656
A polymer having a thioether group shown in No. 4.

(d) Polyvinyl alcohol (e) Acrylic acid polymer Acrylic acid homopolymer, acrylic ester polymer having an amine group, halogenated acrylic ester polymer.

(f) Polymer having hydroxyquinoline ((to) cellulose, starch (h) acetal (1) polyvinylpyrrolidone) Preferably 2% by weight or more.

The temperature of the mixer in method A is 40°C or less, preferably 3
The temperature of the reaction vessel is 50°C or higher, preferably 60°C or higher, and more preferably 70°C or higher.

In method B, the grain formation temperature of the fine grain emulsion prepared in advance is 40°C or lower, preferably 35°C or lower, and the temperature of the reaction vessel to which the fine grain emulsion is added is 50°C or higher, preferably 60°C or higher. The temperature is preferably 70°C or higher.

The grain size of the fine silver halide used in the present invention can be confirmed by directly placing the grains on a mesh and using a transmission electron microscope, preferably at a magnification of 20,000 times to 40,000 times. The size of the fine particles of the present invention is 0.2/A or less, preferably 0.1-A or less, more preferably 0.05m or less.

As mentioned above, Method A uses techniques such as ■ Immediately adding fine particles to the reaction vessel after forming them. Performing strong stirring. ■ Injecting a protective colloid aqueous solution into the mixer, etc., to form fine particles with a smaller size compared to Method B. Can be supplied.

(j) Polystyrene Low molecular weight gelatin is also used in the present invention.

The average molecular weight of gelatin is preferably 30,000 or less, more preferably 10,000 or less.

By using the synthetic protective colloids, natural protective colloids, and low-molecular-weight gelatin that have been shown so far, it is possible to form fine silver halide grains at lower temperatures than when using ordinary gelatin, resulting in smaller grain sizes. Silver halide can be supplied. Regarding the concentration of the protective colloid used, in method A, the concentration of the protective colloid added to the mixer is 0.2% by weight or more, preferably 1% by weight or more, more preferably 2% by weight or more.

When a protective colloid is contained in the silver nitrate aqueous solution and/or the halogen salt aqueous solution, its concentration is 0.2% by weight or more,
Preferably it is 1% by weight or more, more preferably 2% by weight or more.

In Method B, the concentration of the protective colloid aqueous solution in the reaction vessel when preparing the fine grain emulsion in advance is 0.2% by weight.
Above, preferably 1% by weight or more, in this method,
If a silver halide solvent is added to the reaction vessel, a higher dissolution rate of the fine particles and a higher growth rate of the grains within the reaction vessel can be obtained.

Examples of the silver halide solvent include water-soluble bromides, water-soluble chlorides, thiocyanates, ammonia, thioethers, and thioureas.

For example, thiocyanate (U.S. Pat. No. 2,222,264)
No. 2,448,534, No. 3,320,069, etc.), ammonia, thioether compounds (for example, U.S. Pat.
3,704,130, 4,297,439, 4,276.347, etc.), thione compounds (for example, JP-A-53-144319, JP-A-53-82408, JP-A-55-77737, etc.) ), amine compounds (e.g., JP-A-54-100717, etc.), thiourea derivatives (e.g., JP-A-55-2982, etc.), imidazoles (e.g., JP-A-54-100717, etc.), substituted mercaptotetrazoles (e.g., JP-A No. 57-202531, etc.).

The halide composition of the emulsion obtained by the present invention may be any of silver iodobromide, silver chlorobromide, silver chloroiodobromide, and silver chloroiodide, and according to the present invention, the microscopic distribution of halide is uniform. In other words, completely uniform silver halide mixed crystal grains are obtained.

``As an example of completely uniform silver halide emulsion grains,
Here, tabular silver iodobromide grains having a silver iodobromide phase will be explained.

The "completely uniform silver iodide distribution J" mentioned here is completely different from the silver iodide distribution that has been handled up to now, and refers to a more microscopic distribution. Analytical electron microscopy (An
analytical Electron Micro.

5 cops is often used. For example, King (M, A.

King), Loretto (M,) 1. Lorretto
), Maternaghan (T, J, Maternaghan)
``Analytical electron microscopy (analytical electron microscopy)'' by F. and J.
``The Investigation of Iodide Distribution Bianalytical Electron Microscopy'' Progress Inense and
Engineering 118. 1967p, p57 and Takeshi Shiozawa, Photographic Society of Japan Vol. 35, No. 4 1972 p, p2
It can be observed by a direct method using a transmission electron microscope at low temperature as described in 13.

In other words, the silver halide grains were taken out under safe light to prevent the emulsion grains from printing out, and placed on a mesh for electron microscopy, and the sample was heated with liquid nitrogen or liquid helium to prevent damage (printout, etc.) caused by the electron beam. Observation is performed using the transmission method in a cooled state.

The higher the accelerating voltage of the electron microscope, the clearer the transmitted image can be obtained, but up to a particle thickness of 0.251#, it is 200Kv.
olt, 1000K for larger grain thicknesses
Volt is good. The higher the accelerating voltage, the greater the damage to particles caused by the irradiated electron beam, so it is preferable to cool the sample with liquid helium rather than liquid nitrogen.

The imaging magnification can be changed as appropriate depending on the particle size of the sample, but is from 20,000 times to 40,000 times.

When transmission electron micrographs of silver iodobromide tabular grains are taken in this way, partial iodine odor is observed in the silver iodobromide phase. Topographical results of silver iodide content in silver tabular grains are described. The size of the electron beam irradiation probe used in this research was 50 people, but in reality the electron beam spreads due to the elastic scattering of electrons, and the diameter of the electron beam spot irradiated on the sample surface was approximately 300 mm. I end up in a human position. Therefore, this method cannot measure a finer silver iodide distribution. The silver iodide distribution was also measured using the same method in JP-A-58-113927, but the size of the electron beam spot used was 0.2 μ.

Therefore, depending on these measurement methods, more microscopic (10
It is impossible to clarify the silver iodide distribution (local variations on the order of 0 or less).

This microscopic distribution of silver iodide can be seen, for example, in the Hamilton (J, F.) Photographic
Very detailed tree-ring-like striped patterns can be observed on the rhinoceros.

An example of this is shown in FIG. The tabular grains shown here are
Silver bromide tabular grains are used as the core, and silver iodide 10 mol%
A shell of silver iodobromide is formed on the outside of the core, and its structure can be clearly seen in this transmission electron micrograph. In other words, the core part is silver bromide and is naturally uniform, so only a uniform flat image can be obtained, but on the other hand, the silver iodobromide phase has a clear and very fine ring-like striped pattern. can be confirmed. It can be seen that the spacing of this striped pattern is very fine, on the order of <100 people or less, indicating very microscopic non-uniformity.

This very fine striped pattern indicates non-uniformity of silver iodide distribution, which can be revealed by various methods, but more directly, it can be explained by the movement of iodide ions through these tabular grains within the silver halide crystal. Annealing under conditions
A clear conclusion can be drawn from the fact that this stripe pattern completely disappears when exposed to L/C (for example, 250'C for 13 hours).

The tree-ring-like striped pattern indicating the non-uniformity of silver iodide distribution in the tabular silver iodobromide emulsion grains described here is the same as that cited earlier.
It is clearly observed in the transmission electron micrograph attached to JP-A-58-113927, and is also clearly shown in the transmission electron micrograph in the study by King et al. cited earlier. .

Due to these facts, silver iodobromide grains that have been prepared with a constant silver iodide content to obtain a uniform iodide distribution have a very microscopic particle size, which is completely contrary to the intention of their manufacture. It has a non-uniform distribution of silver iodide, and so far no technology has been disclosed to make it uniform, nor has a method for producing it been disclosed.

The present invention discloses an emulsion in which the microscopic silver iodide distribution is completely uniform and a method for producing the emulsion.

As mentioned above, the silver halide grains of the present invention having a "completely uniform silver iodide distribution" can be obtained by observing the transmission image of the grains using a cooled transmission electron microscope. It can be clearly distinguished from silver halide grains. That is, in the silver halide grains containing silver iodide of the present invention, microscopic grains caused by microscopic non-uniformity of silver iodide can be clearly confirmed when measured with a beam microscope. . Such a line due to a change in silver iodide content is completely different from a line resulting from microscopic non-uniformity of silver iodide as referred to in the present invention, and indicates a "macroscopic silver iodide distribution."

In addition, if the silver iodide content is changed substantially continuously during grain growth, there will be no rapid change in the silver iodide content, so the line showing the macroscopic change in the silver iodide content above is not observed, and therefore, if there are at least three or more cotton fibers at 0.1p intervals, this means that there is microscopic non-uniformity in the silver iodide content.

Thus, in the present invention, the "silver halide grains with a completely uniform silver iodide distribution" have 0 in the direction perpendicular to the line in a transmission image of the grains obtained using a cooling transmission electron microscope.
．． Silver halide grains are grains having many (two) lines showing a microscopic silver iodide distribution at 2I# intervals, preferably one, and more preferably no such lines.Furthermore, Such particles account for at least 60% of the total particles
, Sarara 3 , there are at most two trees, preferably one, at 0.2-interval in the direction perpendicular to Sarara 3 , and more preferably none.

The lines that make up the tree-ring-like striped pattern, which shows the microscopic heterogeneity of silver iodide, occur perpendicular to the direction of grain growth.
Consequently, these lines are distributed concentrically from the center of the particle. For example, in the case of the tabular grain shown in Figure 3, the lines constituting the annual ring-like striped pattern, which indicates the non-uniformity of silver iodide, are perpendicular to the growth direction of the tabular grain, and as a result, they are parallel to the edge of the grain. and the direction perpendicular to them points toward the center of the particle, and is distributed concentrically around the center of the particle.

Of course, if the silver iodide content changes rapidly during grain growth, the boundary line will be observed as a line similar to that described above using the observation method described above. consists of only a single line, and can be clearly distinguished from the line composed of multiple lines resulting from microscopic non-uniformity of silver iodide. Furthermore, it is preferred that the line resulting from such a change in silver iodide content accounts for at least 80%, in particular at least 90%, of the silver iodide content on either side of this line for the above-mentioned analytical type.

Conventional silver halide grains, which have been called halide root grains containing uniform silver iodide, are simply
Silver nitrate and a halide mixture of a constant composition (constant iodide content) were simply added to the reaction vessel by the double-jet method, and although the macroscopic silver iodide distribution is certainly constant in such particles, , the microscopic silver iodide distribution is not uniform.

In the present invention, such particles are referred to as particles having a "fixed halogen composition" and are clearly distinguished from the "completely uniform" particles shown in the present invention.

Furthermore, the method of the present invention is also very effective in producing pure silver bromide and pure silver chloride. According to traditional manufacturing methods,
The existence of a local distribution of silver ions and halogen ions in the reaction vessel is inevitable, and silver halide particles in the reaction vessel will pass through such local non-uniform areas and will be separated from other homogeneous areas. will be placed in a different environment,
This not only causes non-uniform growth, but also produces reduced silver or foggy silver in areas with high silver ion concentration. Therefore, in silver bromide and silver chloride, although it is true that there is no non-uniform distribution of halides, the other non-uniformity mentioned above occurs. This problem can be completely solved by the method of the present invention.

Therefore, any silver halide such as silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide, and silver chloride may be used in the photographic emulsion layer of the photographic light-sensitive material used in the present invention. . Preferred silver halides are silver iodobromide, silver chlorobromide, silver chloroiodide, and silver chloroiodobromide containing 3 mol % or more and 40 mol % or less of silver iodide. For silver iodobromide having a silver iodide content of 3 mol % or less, the characteristics of the "completely homogeneous" mixed crystal produced by the method of the present invention are small. In addition, mixed crystals containing silver chloride, such as silver chlorobromide, silver chloroiodide, and silver chloroiodobromide, have a high solubility of silver chloride and tend to become non-uniform, so the method of the present invention is not suitable for completely homogeneous mixing. Characteristics of crystals can be easily seen.

Even if the silver halide grains used in the present invention are normal crystals that do not contain twin planes, the grain size of the silver halide obtained by the Photographic Industry, edited by the Photographic Society of Japan, is 0.1 microns or less, but the projected area diameter is 10 μm. They may be large-sized particles up to microns, or may be monodisperse emulsions with a narrow distribution, or polydisperse emulsions with a wide distribution.

A so-called monodisperse silver halide emulsion having a narrow grain size distribution in which 80% or more of all grains fall within ±30% of the average grain size in terms of grain number or weight can be used in the present invention. In addition, in order to satisfy the target gradation of a light-sensitive material, two or more types of monodisperse silver halide emulsions with different grain sizes are mixed in the same layer or in separate layers in emulsion layers having substantially the same color sensitivity. Can be applied in multiple layers.

Furthermore, two or more types of polydisperse silver halide emulsions or a combination of a monodisperse emulsion and a polydisperse emulsion may be mixed or layered for use.

The photographic emulsion of the present invention was prepared by the method described above, but may be partially prepared by conventionally known methods.

That is, the basis of the photosensitive silver halide grains of the present invention
For example, single twins containing one twin plane, parallel multiple twins containing two or more parallel twin planes, and non-parallel Depending on the purpose, it can be selected and used from non-parallel multiple twin crystals containing two or more twin planes. In the case of normal crystals, there are cubes consisting of (100) planes, octahedrons consisting of (111) planes, and octahedrons consisting of (110) planes disclosed in Japanese Patent Publication No. 55-42737 and Japanese Patent Publication No. 60-222842. Particles can be used. In addition, Journalof Imagi
ng 5science Volume 30 Page 247 198
(211) as reported in 2006 is representative (
hll) surface particle, (hhl) surface particle represented by (331), (hko) surface particle representing (210) surface, and (3
(hkl) plane particles, which are represented by 21) planes, can also be selected and used depending on the purpose, although the preparation method requires some ingenuity.

Tedecahedral particles in which (100) and (111) planes coexist in one particle, particles in which (100) and (110) planes coexist, or particles in which (111) and (110) planes coexist, etc. Particles having two surfaces or a large number of surfaces coexisting can also be selected and used depending on the purpose.

In the preparation, the entire particle may be prepared by the method of the present invention, or the method of the present invention may be applied as part of the preparation of the particles, and the rest may be carried out by conventional known methods. For example, only the core or shell of a core-shell type particle in which the interior and surface of the particle have different halogen compositions may be prepared by the method of the present invention, and the rest may be prepared by a known method, or the interior and surface layers with the same halogen composition may be prepared by the method of the present invention. The method of the present invention as described above and known methods may be used in combination for the preparation. Similarly, in the preparation of particles having a bonded structure (evixaxial particles), the method of the present invention and the known method may be applied separately for the preparation of the host and the guest.

Further, the photographic emulsion layer of the photographic light-sensitive material of the present invention may contain a photographic emulsion that is not produced by the manufacturing method of the present invention. Regarding these, see "Physics and Chemistry of Photography" by Glafkides, published by Beaumontel (P, Glafkides,
Chimie et Physique Photog
raphique Paul Montel, 1967
), "Photographic Emulsion Chemistry" by Duffin, published by Focal Press (G, F. Duffin, Photography
cEmulsion Chemist-ry (Foc
al Press+ 1966), Zelikman et al.
"Production and Coating of Photographic Emulsions", published by Focal Press (■几, Zelikman et al, Makingan
dCoating Photographic Emu
lsion, Focal Press 1964). That is, any of the acidic method, neutral method, ammonia method, etc. may be used, and the method for reacting the soluble silver salt with the soluble halogen salt may be any one-sided mixing method, simultaneous mixing method, or a combination thereof. . It is also possible to use a method in which particles are formed in an excess of silver ions (so-called back-mixing method). As one form of the simultaneous mixing method, a method in which the pAg in the liquid phase in which silver halide is produced can be kept constant, that is, a so-called Chondrald double jet method can also be used. According to this method, a silver halide emulsion having a regular crystal shape and a nearly uniform grain size can be obtained.

The above-mentioned silver halide emulsion consisting of regular grains can be obtained by controlling pAg and pi during grain formation.
, 434.226. Tabular grains are preferred as emulsions of the present invention.

In particular, particles with an aspect ratio of 3 to 8 account for 50% of the total projected area.
Tabular grains occupying the above amount are preferable.

The crystal structure may be --like, the inside and outside may have different halogen compositions, or it may have a layered structure. These emulsion grains are described in British Patent No. 1,027,1
No. 46, U.S. Patent No. 3,505,068, U.S. Patent No. 4,44
No. 4,877 and Japanese Patent Application No. 58-248469. Furthermore, silver halides having different compositions may be bonded by epitaxial bonding, or compounds other than silver halide such as silver rhodan or lead oxide may be bonded.

The silver halide emulsion of the present invention preferably has a distribution or structure in terms of halogen composition in its grains.

Typical examples are JP-B No. 43-13162, JP-A No. 61-215540, JP-A No. 60-222845,
These are core-shell type or double-structured particles in which the interior and surface layers of the particles have different halogen compositions, as disclosed in JP-A No. 61-75337.

・Science and Engineering (Photo
graphic 5science and lEngi
6, pp. 159-165 (1962
); Journal of Photographic 1 Science
5science) + 12, 242-251 (1964), US Pat. No. 3,655,394 and British Patent No. 1,413.748.

Further, tabular grains having an aspect ratio of 3 or more can also be used in the present invention. Tabular grains are described in ``Theory and Practice of Photography J'' by Creep.
hy Theory and Practice (1
930)) +131 pages; Gatoff, Photographic
Science and Engineering (Cutoff)
, Photographic 5science and
Engineering) + Volume 14, 248-2
57 pages (1970); U.S. Patent No. 4,434,226
No. 4,414,310, No. 4,433,048, No. 4,439,520 and British Patent No. 2.112
．． It can be easily prepared by the method described in No. 157 and the like. When tabular grains are used, there are advantages such as increased covering power and increased color sensitization efficiency with sensitizing dyes. The overall shape may be the same or different. Specifically, the core part has a cubic shape, and the shape of the shelled particle may be cubic or octahedral. Conversely, the core may be octahedral and the shelled particle may be cubic or octahedral. Furthermore, although the core portion is a clearly regular particle, the shelled particle may have a distorted shape or an irregular shape. In addition, instead of a simple double structure, it is possible to have a triple structure as disclosed in JP-A-60-222844, or a multilayer structure with more than that, or to have a core-shell double structure with different compositions on the surface. It is possible to apply a thin layer of silver halide.

In order to give a structure to the inside of a particle, it is possible to create a particle having not only the above-mentioned enveloping structure but also a so-called bonding structure. These examples are disclosed in Japanese Patent Application Laid-Open No. 59-13354.
No. 0, Japanese Patent Publication No. 58-108526, EP199290
A2, JP 58-24772, JP 59-162
It is disclosed in No. 54, etc. The crystal to be bonded has a composition different from that of the host crystal, and can be formed by bonding to an edge, a part of a corner, or a surface of the host crystal. Such a bonded crystal can be formed even if the host crystal is uniform in terms of halogen composition or has a core-shell structure. In the case of a bonded structure, a combination of silver halides is naturally possible, but a bonded structure can be obtained by combining a silver halide with a silver salt compound that does not have a rock salt structure, such as rhodan, silver, or silver carbonate.

Further, non-silver salt compounds such as pbo may also be used if a bonded structure is possible.

In the case of silver iodobromide grains having these structures, for example, in a core-shell type grain, even if the core part has a high silver iodide content and the shell part has a low silver iodide content, or conversely, the core part has a low silver iodide content. The particles may have a low silveride content and a high shell portion. Similarly, grains having a bonded structure may be grains in which the host crystal has a high silver iodide content and the bonded crystal has a relatively low silver iodide content, or vice versa.

It varies depending on the intended use. There are cases in which chemical sensitizing nuclei are embedded inside particles, in cases where they are embedded at a shallow position from the particle surface, or in cases where chemical sensitizing nuclei are created on the surface. Although the effects of the present invention are effective in any case, it is particularly preferable to create chemically sensitized nuclei near the surface. In other words, surface latent image type emulsions are more effective than internal latent image type emulsions.

Chemical Enhancement, James (T, 11.James), The Photographic Process, 4th Edition, Macmillan Publishing Co., Ltd., 1977, (T, H, James+T
he theory of the photograp
hic Process, 4th ed, Macm
Illan 1977) 67-76 and can be carried out using activated gelatin as described in Research Disclosure, Vol. 120, April 1974;
12008; Research Disclosure Volume 34,
June 1975, 13452, U.S. Patent No. 2,642
, No. 361, No. 3,297,446, No. 3.772.
No. 031, No. 3,857.711, No. 3,901゜7
No. 14, No. 4,266.018 and No. 3,904,
415 and as described in British Patent Section 1315.755 pHgs ~ 10, pH 5-8 and temperature 30
~80'C, sulfur, and the boundaries between particles with these structures with different halogen compositions may be clear boundaries or may be unclear boundaries due to the formation of mixed crystals due to compositional differences. , or those with continuous structural changes may also be used.

The silver halide emulsion used in the present invention is BP-009672
781, EP-0064412B1, or DB-2.
306447G2, surface modification as disclosed in JP-A No. 60-221320 may be carried out.

The silver halide emulsion used in the present invention is preferably a surface latent image type emulsion, but an internal latent image type emulsion may also be used by selecting the developer or development conditions, as disclosed in JP-A-59-133542. Can be done.

In addition, a shallow internal latent image type emulsion overlaid with a thin shell can also be used depending on the purpose.

In the present invention, it is extremely important to perform chemical sensitization, typified by sulfur sensitization and gold sensitization, in addition to reduction sensitization. The location where chemical sensitization is applied depends on the composition, structure, and shape of the emulsion grains, and whether the emulsion is used for selenium, tellurium, gold, platinum,
This can be done using palladium, iridium or a combination of these sensitizers. Chemical sensitization is optimally
In the presence of a gold compound and a thiocyanate compound, sulfur-containing compounds or hypo, thiourea-based compounds, rhodanine as described in U.S. Pat. It is carried out in the presence of a sulfur-containing compound such as a sulfur-containing compound. Chemical sensitization can also be carried out in the presence of chemical sensitization aids. The chemical sensitization aid used is a compound known to suppress fog and increase sensitivity during the chemical sensitization process, such as azaindene, azapyridazine, and azapyrimidine. Examples of chemical sensitization aid modifiers include U.S. Patent No. 2,131
, No. 038, No. 3,411,914, No. 3,554,
No. 757, JP-A-58-126526, and the aforementioned "Photographic Emulsion Chemistry" by Duffin, pp. 138-143.

When chemical sensitization using gold salt is performed, the formation of fog due to the reaction between reduced silver nuclei and gold salt is prevented by adding the oxidizing agent and/or inhibitor prior to grain formation in the region. It is preferable. For example, when a gold salt is used in chemical sensitization of the particle surface, it is preferable that particle formation in an area of at least 77 m from the particle surface is carried out in the presence of an inhibitor.

The photographic emulsion used in the present invention can contain various compounds for the purpose of preventing fog during the manufacturing process, storage, or photographic processing of the light-sensitive material, or for stabilizing photographic performance. Namely, azoles such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, promohenzimidazoles, mercaptothiazoles, mercaptohendithiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles. penditriazoles, nitrobenzotriazoles, mercaptotetrazoles (especially 1-phenyl-5-mercaptotetrazole), etc.; mercaptopyrimidines frequently; mercaptotriazines; for example, oxadolinthiosazoline nucleus, thiozoline nucleus, pyrrole nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc.; a nucleus in which an alicyclic hydrocarbon ring is fused to these nuclei; and a nucleus in which an aromatic hydrocarbon ring is fused to these nuclei, i.e., Indolenine nucleus, benzindolenine nucleus, indole nucleus, benzoxadole nucleus, naphthoxadole nucleus, penzothiazole nucleus, naphthothiazole nucleus, benzoselenazole nucleus, benzimidazole nucleus, quinoline nucleus, etc. can be applied. 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, thiobarbic acid nucleus, etc. can be applied.

These sensitizing dyes may be used alone or in combination; thioketo compounds such as combinations of sensitizing dyes; azaindenes, such as triazaindenes, tetraazaindenes (especially Many compounds known as antifoggants or stabilizers can be added, such as 4-hydroxy-substituted (1,3,3a,7)tetraazaindenes), penquazaindenes, and the like.

For example, U.S. Patent No. 3,954,474, 3.9
Those described in No. 82.947 and Japanese Patent Publication No. 52-28.660 can be used.

The photographic emulsions used in the present invention may be spectrally sensitized with methine dyes and others. The 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 basic heterocyclic nuclei commonly used in cyanine dyes can be applied to these dyes. That is, the pyridine nucleus, in particular, is often used for the purpose of supersensitization.

Representative examples are U.S. Pat. No. 2,688,545 and U.S. Pat.
No. 977229, No. 3,397,060, No. 3.52
No. 2.052, No. 3.527641, No. 3,617.
No. 293, No. 3,628.964, No. 3,616゜4
No. 80, No. 3,672,898, No. 3,679,4
No. 28, No. 3703.377, No. 3,769,301
No. 3,814.609, No. 3, 837, 86
No. 2, No. 4,026,707, British Patent No. 1.344
No. 281, No. 1,507.803, Special Publication No. 43-49
No. 36, No. 53-12,375, JP-A No. 52-110
, No. 618 and No. 52-109,925.

Along with the sensitizing dye, it is a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light,
A substance exhibiting supersensitization may also be included in the emulsion.

The dye may be added to the emulsion at any stage of emulsion preparation known to be useful.

Most commonly, this is done after chemical sensitization is completed and before application, but as described in U.S. Pat. No. 3,628,969 and U.S. Pat. Spectral sensitization can be carried out at the same time as chemical sensitization by adding it at the same time, or it can be carried out before chemical sensitization as described in JP-A-58-113928. It is also possible to start the spectral sensitization by adding it before the completion of the spectral sensitization. Furthermore, U.S. Patent No. 4.225
．． It is also possible to add these said compounds separately as taught in No. 666, i.e. some of these compounds can be added before chemical sensitization and the rest after chemical sensitization. and at any time during silver halide grain formation, including the method taught in U.S. Pat. No. 4,183,756.

The amount added is 4 x lO-' to 8 per mole of silver halide.
Although it can be used in amounts of X10-3 moles, about 5×10-5 to 2×10-' moles are more effective when the silver halide grain size is more preferably 0.2 to 1.27n+.

In addition to the above-mentioned additives used in the photosensitive material related to the present technology, various other additives can be used depending on the purpose.

These additives are described in more detail in Research Disclosure Item 17643 (December 1978).
and [Examples] The present invention will be further explained with reference to Examples below.

Example 1 Silver iodobromide tabular grain silver iodobromide fine grain emulsion 1-A 1 was added to 2.6 f of a 20 wt % gelatin solution containing 0.026 M potassium bromide by a double jet method while stirring. .2M nitric acid 1i1? 1200 ml each of liquid g and an aqueous halogen salt solution containing 1.11 M potassium bromide and 0.09 M potassium iodide were added over 15 minutes. During this time, the gelatin solution was maintained at 35°C.

After this, the emulsion was washed by a conventional flocculation method, and 30 g of gelatin was added and dissolved.
' Adjusted to 1g 8.6. The obtained silver iodobromide fine particles (silver iodide content 7.5%) had an average particle size of 0.07.
It was p.

Tabular silver bromide core emulsion L-B 0.8% by weight gelatin containing 0.09M potassium bromide? Stir the mixture overnight at 2°C and add a 2.0M silver nitrate solution and a 2.0M potassium bromide solution at 30C using the double jet method.
em18716 (November 1979), and the relevant parts are summarized in the table below.

Additive type Chemical sensitizer Sensitivity enhancer RD/7643 Page 23 RD/8716 Page 648 Right column Same as above 4 Brightener Page 24 Anti-stain agent Dye Image stabilizer Hardener Binder Plasticizer, lubricant Page 25 Right column 25 Page 26 Page 26 Page 27 Page 650 Left to right columns Page 651 Left column Same as above 650 Right column 13 Sulfic inhibitor Page 27 Same as above The gelatin solution in the reaction vessel was maintained at 30°C. After the addition, the temperature was raised to 75°C, and 40g of gelatin was added. A 1.0 M silver nitrate solution was then added to bring the pBr to 2.55, after which 150 g of silver nitrate was added over 60 minutes at an accelerated flow rate (end flow rate was 10 times the starting flow rate), and at the same time double jet Potassium bromide was added to give a pBr of 2.55.

After this, the emulsion was cooled to 35°C and washed with water using a conventional flocculation method, and 60g of gelatin was added and dissolved at 40°C. pl+ 6.5, pAg 8.6
Adjusted to. The tabular silver bromide grains have an average equivalent circular diameter of 1.4. The grains were monodisperse tabular grains with a grain thickness of 0.2If @ and a coefficient of variation of circular phase diameter of 15%.

Tabular silver iodobromide emulsion I-C <comparative emulsion> 5 with silver nitrate
Emulsion 1B containing silver bromide equivalent to 0 g was dissolved in 1.1 i of water at a temperature of 75° C. and 1 pBr of 1.5. Thereafter, immediately after adding 1 g of 3.6-cythiaoctane-1,8-diol, a potassium bromide solution containing 100 g of silver nitrate and 7.5 M% of potassium iodide was added at a constant flow rate in equimolar amounts to silver nitrate over a period of 50 minutes. After that, it was washed with water using the usual flocculation method, and the pH was adjusted to 6.5, pAg.
Adjusted to 8.6. The obtained silver iodobromide tabular grains were
The center part is silver bromide and the outer ring part is silver iodide 7.5M%
Silver iodobromide with an average circular equivalent particle diameter of 2.3p
The particle thickness was 0.30 mm.

Tabular Silver Iodobromide Emulsion 1-D <Comparative Emulsion> Prepared in the same manner as Emulsion 1-C except for the following. Instead of adding silver nitrate aqueous solution and halogen salt aqueous solution to the reaction vessel, fine grain emulsion 1-A was added to IIl! It was added to the reaction vessel at a constant flow rate over 50 minutes so that the amount was 100 g in terms of silver i-acid. The obtained tabular grains had an average circular equivalent diameter of 2.4p and a grain thickness of 0.3
It was 1ρ.

Tabular silver iodobromide emulsion T -E, F, G, +1 <Comparative emulsion> In the preparation of tabular silver iodobromide emulsion 1-C,
Emulsions 1-E and F were prepared in the same manner as Emulsion 1-C, except that the reduction sensitizer shown in Table 1 was added 2 minutes after the start of addition of the mixed solution of silver nitrate solution, potassium iodide, and potassium bromide.
, G, l( were prepared. The particle size was equivalent to ■-C.

Sensitized color i5-ri4row5"-phenyl-3,3"-(3
sulfopropyl)-9-ethyloxacarbocyanine (
240 mg/AgX 1 mol) was added, followed by sodium thiosulfate (8 x 10-' mol/AgX 1 mol) for optimal chemical sensitization at 60'C. After chemical sensitization, 100 g of each emulsion (containing 08 moles of Ag O) was heated at 40°
The mixture was dissolved in C and the following steps 1 to 2 were sequentially added while stirring to prepare a solution.

■ 4-hydroxy-6= methyl-1,3,3a,7-chitrazaindene 3% 2 cc■ C+J,
+5-O-(CHzCHO)zs-112% 2.2
cc ■ Sodium 2,4-dichloro-6-hydroxy-S triazine 2% 3 cc Coating liquid for surface protective layer A liquid was prepared by adding (1) to (2) sequentially with stirring at 40°C according to the following procedure.

■ 14% gelatin aqueous solution 56.8 g Tabular silver iodobromide emulsion 1-LJ, K <Invention> In the preparation of tabular silver iodobromide emulsion D, the table was added 2 minutes after the start of addition of fine grain emulsion A. Emulsion 1-1. J and K were prepared. The particle size was similar to ID.

Tabular silver iodobromide emulsion 1-L, M, N, O <comparative emulsion>
In the preparation of tabular silver iodobromide emulsions 1-E, F, G, and If, the emulsions were prepared except that the oxidizing agent shown in Table 1 was added immediately before starting the addition of the silver nitrate solution, potassium iodide, and potassium bromide mixed solution. Emulsion 1-L in the same manner as I-E, F, G, H,
M, N, and O were prepared. Regarding particle size, it was equivalent to 1-C.

Tabular silver iodobromide emulsions 1-P, Q, R <Present invention> In the preparation of tabular silver iodobromide emulsions 1-T, J, the following steps as shown in Table 1 were added immediately before starting addition of fine grain emulsion 1-A. Emulsion 1-I was prepared in the same manner as Emulsion 1-I, J, except that the oxidizing agent shown was added.
P, Q, and R were prepared. The particle size was similar to ID.

The emulsion I-C-I-R prepared in the above manner was subjected to spectroscopy.
Polymethyl methacrylate fine particles (average particle size 3.Op) Emulsion gelatin 10% 4.24 g3.9
g C112C00C)12c)l(C2H5)C4H9N
a03S CHCOOCHzCH(CJs)C4H+
10.6 mg ■ 8.0 68.8 cc 4.3% cc Coated on a polyethylene terephthalate film support by co-extrusion together with the emulsion coating solution and surface protective layer coating solution obtained as above. The coating was applied so that the volume ratio of the two was 103.45. Coated silver amount is 3.1
g/rrr. These samples were exposed to light ('/loo seconds) using a sensitometer through a yellow filter and an optical pattern, and then treated with RD-1 developer for automatic processors (
After developing for 30 seconds at 35°C using Fuji Photo Film (manufactured by Fuji Photo Film), the film was fixed, washed with water, and dried in a conventional manner, and the photographic sensitivity was measured. Photographic sensitivity is expressed as a relative value of the reciprocal of the exposure amount necessary to obtain an optical density of fog value +0.5, and sample 101 was taken as 100.

As shown in Table 1, the sensitivity increases with the addition of a reduction sensitizer, but emulsion samples 103-106 in which grain growth in the presence of a reduction sensitizer was carried out by adding a silver nitrate aqueous solution and a halogen salt aqueous solution In contrast, in sample 107-109, an emulsion in which grains were grown by the method of the present invention, the increase in fog was small, and the fog increased significantly during the increase in sensitivity due to reduction sensitization. It has been shown that the objective of providing an emulsion with high sensitivity and low fog has been achieved.

By coexisting the compound of general formula (1) as an oxidizing agent during reduction sensitization, it has been possible to reduce fog without adversely affecting sensitivity. Samples 110 to 113, which were emulsions made by adding an aqueous salt solution, had significantly lower sensitivity than samples 107 to 109 of the present invention, which had approximately the same strength. On the other hand, samples 114-116, which were subjected to reduction sensitization in the presence of an oxidizing agent according to the method of the present invention, had substantially the same degree of density as sample 102 without reduction sensitization, and were significantly higher in sensitivity.

Example 2 Emulsion 1-C, D, ILK, O, R was prepared in the same manner as in Example 1.
Sodium benzenethiosulfmenate (2 x 10-' mol 1 mol Ag), sodium thiosulfate (1 x 10-s mol 1 mol Ag), and chloroauric acid (2 x 1 mol Ag) were prepared.
0-S mol 1 mol Ag) and potassium thiocyanate (3,
Optimal chemical sensitization was carried out at 60"C by adding 2X 10-' mol 1 mol Ag). After completion of chemical sensitization, coated samples 201-206 were prepared in the same manner as in Example 1, and a yellow filter was used during exposure. The results shown in Table 2 were obtained in the same manner as in Example except for the above.Sensitivity is expressed as a relative value with sample 201 set as 100.Sodium benzenethiosulfmenate used here has the general formula (1). Although it is a compound contained in
The fog and sensitivity of Emulsions 1-C and 1-D were hardly affected, but the fog values of Emulsions 1-H and OR were decreased without changing the sensitivity. However, even if it was increased from the scene used here, the cover value did not change much.

As shown in Table 2, even when gold sensitization was used, samples 204 and 206 of the present invention exhibited significantly high frequencies and low fog. Sample 203.205 of an emulsion in which grain growth during reduction sensitization was carried out by adding a silver nitrate aqueous solution and a halogen salt aqueous solution.
It becomes more noticeable when the temperature is increasing, and it is small even when the sensitivity is increasing due to reduction sensitization.

Table 2 201 Comparative Example 204 Invention 205 Comparative Example 206 Invention C D HL-7 Scorbic Acid 2X10-' to 0 0x-3
5X10-5-R0x-3 0,15 0,14 0,33 0,18 0,20 0,15 Example 3 Silver iodobromide octahedral grain emulsion 3-A <Comparative emulsion> 0.06M potassium bromide 3.0ml 1% gelatin solution containing ? li 1.2 p., stirring it for 3
6-cythiaoctane-1,8-diol 5% water? Yong? 20m1 at night! 0.3M in a reaction vessel kept at 75°C.
Halogen salt aqueous solution 5 containing 50 cc of silver nitrate solution, 0.063 M potassium iodide, and 0.19 M potassium bromide
0 cc was added over 3 minutes using the double jet method.

Thereby, nucleation was performed by obtaining silver iodobromide grains having a projected area equivalent diameter of 0.2 capes and a silver iodide content of 25 mol %. Subsequently, 60 mfl of 3.6-cythiaoctane-1.8-diol was added at 75°C,
800 mf of 1.5 M nitric acid II and 800 d of a halogen salt solution containing 0.375 M potassium iodide and 1.13 M potassium bromide were simultaneously added over 100 minutes by a double jet method to form a first coating layer. The pH in the reaction vessel up to this point was maintained at 6.5. The obtained emulsion grains were octahedral silver iodobromide emulsions with an average projection plane equivalent diameter of an ellipse of 0.95p (iodide content: 25 mol %).

Subsequently, after adding 0.06 mol of hydrogen peroxide, this emulsion was used as a core emulsion, and 1.5 M silver nitrate aqueous solution and 1.5 M potassium bromide aqueous solution were simultaneously added in equimolar amounts to form a silver bromide shell (second A coating N) was formed.

The silver bromide second coating layer had a molar ratio of first coating layer/second coating layer of 1:1. p)+ during shell formation was kept at 5.8. The resulting emulsion grains were core/shell monodisperse octahedral grains with an average equivalent circular diameter of 127x and containing 25 mol % of silver iodide inside.

Emulsion 3-B Comparative Emulsion> After each formation was carried out in the same manner as Emulsion 3-A, 3,6-cythiaoctane-1,8-diol was added and a mixer with strong and efficient stirring was installed near the reaction vessel. 800ml of 1.5M silver nitrate, 0.375M potassium iodide and 1.13ml of
Halogen salt solution containing M potassium bromide 800 mN and 2
A 500% by weight aqueous gelatin solution was added over 100 minutes using a triple jet method. At that time, the temperature of the mixer is 3
It was kept at 0'C. The ultrafine particles produced in the mixer were immediately introduced into a reaction vessel continuously maintained at 75°C to form a first coating layer. Up to this point, pl+ in the reaction vessel was maintained at 6.5. After that, hydrogen peroxide was added, and then 1.5M silver nitrate solution and 1.5M potassium bromide solution were added.
% by weight gelatin solution into a mixer to form a silver bromide shell (second coating layer).
Particles with a coating layer ratio of 1:1 were obtained. pl when forming the second coating layer
+ was kept at 5°8. The obtained particles had a circular phase groove diameter of 1.2p.
No. 8 (1) Emulsion layer/emulsion Emulsion/coupler shown in Table 3 - Tricresyl phosphate/enhancing dye ) Oxalylic lupocyanine sodium/stabilizer 4-hydroxy-6-methyl-13,3a,
7-Chitrazaindene antifoggant 1-(m-sulfophenyl)5-mercaptotetrazole coating aid Sodium dodecylhenzenesulfonate Hedron monodisperse core/shell emulsion grains.

Emulsion 3-C, D <Comparative emulsion> Emulsion 3-C was prepared in the same manner as Emulsion 3-A except that the pH during core formation and shell formation of Emulsion 1-A was changed as shown in Table 3.
, D were prepared. Particle size was approximately the same.

Emulsion 3-E, F <Present invention> Pi at the time of core formation and shell formation of Emulsion 3-B
Emulsion 3-B was prepared in the same manner as Emulsion 3-B except for the following changes.
E and F were prepared. Particle size was approximately the same.

The emulsion obtained above was heated at 56°C with sodium benzenethiosulfonate (2×10-' mol 1 mol Ag).
), sodium thiosulfate (1,2X10-' mol 1 mol Ag), chloroauric acid (1,6X10-S mol 1 mol A
g) and potassium thiocyanate (2,5X10-' mol 1
Mole Ag) was added for optimal chemical sensitization. Thereafter, the compounds shown below were added and coated together with a protective layer on a triacetyl cellulose film support having an undercoat layer by a coextrusion method.

(2) Protective layer - 2,4-dichloro-6-hydroxy-5-) riazine sodium salt - gelatin These samples were filtered through a yellow filter. . A second sensitometric exposure was applied, followed by color development.

The concentration of the treated sample was measured using a green filter.

The results of the photographic performance obtained are shown in Table 3. The sensitivity was determined as the reciprocal of the exposure amount that gives a density of fog +0.5.

Relative sensitivity was set at 100 for sample 301. The development process used here was carried out at 38°C under the following conditions.

1. Color development ---1 -------2 minutes 45 seconds 2
, bleaching-------6 minutes 30 seconds 3, water
Washing -------3 minutes 15 seconds 4, fixing-
1111...6 minutes 30 seconds 5, water washing---1---3 minutes 15 seconds 6, stable 3 minutes 15 seconds The treatment liquid composition used in each step is as follows. It is.

Color developer Sodium nitrilotriacetate 1.0g Sodium sulfite 4.0g Sodium carbonate 30.0g Potassium bromide
1.4g hydroxylamine sulfate 2.4g 4-(N-ethyl-
Add 4.5g of N-βhydroxyethylamino)-2-methylaniline sulfate and water.
1℃ Bleach solution Ammonium bromide 160.0g Aqueous ammonia (28%) 25.0mN
Ethylenediamine-tetraacetic acid sodium salt 130g Glacial acetic acid 14ml Add water lJ2 fixer Sodium tetrapolyphosphate 2.0g Sodium sulfite 4.0g Ammonium thiosulfate (70%) 175.0mR Sodium bisulfite water Add stabilizer Formalin water 4.6g 8゜0mlt As shown in Table 3, Sample 305.306 of the present invention has low fog and high sensitivity. Furthermore, sample 30 of comparative example
It also showed favorable results in that the gradation was harder than that of 1,303,304.

Example 4 The emulsion used in Example 2 of this specification and the emulsion used in Example 3 were replaced with the emulsion of the 5th layer and the 16th layer of Example 5 of Japanese Patent Application No. 1983-7853. It was confirmed that a photographic material with high sensitivity and low fogging was obtained in samples using the emulsion of the present invention.

Example 5 Silver chlorobromide fine grain emulsion 5-A A 2 to 3 weight % gelatin solution containing 0.01M potassium bromide and 0.05M sodium chloride was added to 1.31% of gelatin solution with stirring using a double jet method. A halogen salt aqueous solution containing 1.2M silver nitrate aqueous solution, 0.72M potassium bromide, and 1.0M sodium chloride was added at 600% each over 25 minutes. During this time, the gelatin solution in the reaction vessel was maintained at 35°C. Thereafter, the emulsion was washed by a conventional flocculation method, and 30 g of gelatin was added and dissolved, and the pH was adjusted to 6.5.

The obtained silver chlorobromide fine particles (silver chloride content 40%) had an average particle size of 0.09-.

Silver chlorobromide octahedral grain emulsion 5-B <Comparative emulsion> 0.0
To a 3.0 wt% gelatin solution containing 65 M potassium bromide and 0.3 M sodium chloride, add 0.1 x 3.4-dimethyl 4-thiazoline-2-thione in methanol while stirring it. Melt? Add BOml to the night 75
Add 50cc of 0.3M silver nitrate solution to a reaction vessel kept at °C.
Then, 50 cc of a halogen salt aqueous solution containing 0.18 M potassium bromide and 0.8 M sodium chloride was added over 3 minutes using a double jet method.

Nucleation was performed by obtaining 0.3 us silver chlorobromide grains having a silver chloride content of 40 mol %. Subsequently, 800 cc of an aqueous solution containing 150 g of silver nitrate, 800 cc of an aqueous solution containing 63 g of potassium bromide, and 43 g of sodium chloride were simultaneously added by double jet over a period of 100 minutes at 75°C. After this, the emulsion was cooled to 35°C and washed with water using a conventional flocculation method.
0g was added to adjust the pH to 6.2 and pAg to 7.8.

Note that the pH in the reaction vessel during particle formation was adjusted to 4.5. The grains were silver chlorobromide octahedral grains of 1.5p and a silver chloride content of 40 mol%.

Silver chlorobromide octahedral grain emulsion 5-C <Comparative emulsion> Emulsion 5-
After carrying out nucleation in the same manner as in B to obtain silver chlorobromide core grains of 0.3/A, fine grain emulsion 5 was dissolved at 75°C.
-A (silver chloride content 40 mol%) was added to the reaction vessel using a pump. The fine grain emulsion was added over 100 minutes at an addition rate of 150 g in terms of silver nitrate. At this time, 1.20 g of sodium chloride was dissolved in advance in the fine grain emulsion. After this, the emulsion was washed with water in the same manner as Emulsion 5-B, and
It was adjusted to pl+6.5 and llAg7.8 in C. The pH inside the reaction vessel during particle formation was adjusted to 4.5.

The resulting grains were silver chlorobromide octahedral grains with a silver chloride content of 40 mol % and 1.5p.

Silver chlorobromide octahedral grain emulsion 5-D, Ii <Comparative emulsion> In the preparation of silver chlorobromide octahedral grain emulsion 5-B, the pH in the reaction vessel during grain formation was changed as shown in Table 5. Emulsion 5-DE was prepared in the same manner as Emulsion 5-B. However, the addition rates of the silver nitrate aqueous solution and the halogen salt aqueous solution during nucleation were adjusted so that they were the same as the particle size.

Silver chlorobromide octahedral grain emulsion 5-F, G <Invention> L of silver chlorobromide octahedral grain emulsion 5-C (manufactured by 8, the pH in the reaction vessel during grain formation was shown in Table 5) Emulsion 5-C (c) Color image stabilizer Further stabilizer; 4-hydroxy-6-methyl-1,3,3a,
7-Chitrazaindene antifoggant; 1-(3-(3-methylureido)
Phenyl]-]5-mercaptotetrazole membrane agent; 2,4-dichloro-6-hydroxy-5-) riazine sodium coating aid; sodium dodecylhenzenesulfonate was sequentially added to the paper support laminated on both sides with polyethylene. On top was coated with a gelatin protective layer.

The samples were exposed under a light wedge and developed according to the following steps to obtain the results shown in Table 5.

However, the relative sensitivity was the relative value of the reciprocal of the exposure amount necessary to give a density with a value of fog value + 0.5. Emulsions 5-F and G were prepared in the same manner as in the above. The grain → noise was made to be the same by adjusting the addition rate of the fine grain emulsion.

Emulsion 5-B-G was optimally post-ripened at 52°C by adding 150 mg 1 mol Ag of the blue-sensitive sensitizing dye (a) shown below and then adding sodium thiosulfate (1,2 x 10-5 mol 1 mol Ag). Also, the following yellow coupler, color image stabilizer, (a) blue-sensitive sensitizing dye (b) yellow coupler C di5OJ-N (CzHs): 1, and that of sample 501 with a development time of 3 minutes 30 seconds as 100. did.

(Color developer) 33'C development 2'30" and 3'
30" water 80
0 cc diethylenetriaminepentaacetic acid 1,
0g sodium sulfite 0.2gN,
N-diethylhydroxylamine 4.2g Potassium bromide 0.01g Sodium chloride 1.5g Triethanolamine 8.0g Potassium carbonate
30 g N-ethyl-N-(β-methanesulfonmidoethyl)-3-methyl-4-aminoaniline sulfate 4.5 g 4.44'-diaminostilbene type 2.0 g Fluorescent brightener (Sumitomo Chemical Whitex4) Power up the water
At 1000 ccKOH
pl+ 10.25 (bleach-fix solution formulation)
35°C 45 seconds Ammonium thiosulfate (5htχ) NazSOi Nl+4(Fe (I[l) (EDTA) :]E
DTA ・2Na Add glacial acetic acid water and make the total amount 150m 5 g 5 g g 8.61 g 1000 ml (pif 5.4) 90 seconds (Rinse liquid prescription) 35°C EDTA ・2Na ・211zO Add water and make the total amount 0.4 g 1000 (pH 7,0) Table 5 is a detailed diagram.

Figure 3 is a transmission electron micrograph showing the crystal structure of conventional tabular silver halide grains in which the iodine distribution in the silver iodobromide phase is not completely uniform, and the magnification is 37,000 times. .

1-Reaction vessel 2: Protective colloid aqueous solution 3: Propeller 4; Halogen salt aqueous solution addition system 5: Silver salt aqueous solution addition system 6: Protective colloid addition system 7: Mixer 8: Introduction system to reaction vessel 9: Stirring blade 10: Reaction chamber 11: rotating shaft As is clear from Table 5, samples 505 and 506 of the present invention
The sample has higher sensitivity than the comparative sample, and the variation in photographic performance due to development time is small, making it suitable for rapid processing. Comparative samples 501, 503, and 504, in which grain growth was carried out by adding an aqueous silver nitrate solution and an aqueous halogen salt solution, had large fluctuations in photographic performance depending on development time, and samples 503 and 504 had significant fogging.

The features of the present invention, such as high sensitivity, low fog, and small fluctuations in photographic performance due to development time, are due to the high silver chloride cubic grains (silver chloride 99 mol%, silver bromide 1 mol% (unevenly distributed in the corners)). ) was almost maintained.

[Effects of the Invention] The photographic material obtained by the method of the present invention has high sensitivity and little fog, and also has high sensitivity and good granularity.

[Brief explanation of the drawing]

FIG. 1 schematically represents an emulsion reactor that can be used in the method of the present invention. Figure 2 shows a diagram of a mixer that can be used in the present invention.

Claims (1)

[Scope of Claims] 1) In a silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support, the light-sensitive silver halide grains contained in the silver halide emulsion layer are It is obtained by adding fine-sized silver halide grains prepared in advance to a reaction vessel in which grain nucleation and/or crystal growth is caused. 1. A silver halide photographic material comprising photosensitive silver halide grains which have been reduction sensitized. 2) In a silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support, the light-sensitive silver halide grains contained in the silver halide emulsion layer are capable of nucleation of the grains and/or Alternatively, fine-sized silver halide particles prepared in advance are placed in a reaction vessel in which crystal growth is caused.
1. A silver halide photographic material, characterized in that it is a photosensitive silver halide grain obtained by adding the grains under conditions capable of reduction sensitization and causing nucleation and/or crystal growth in the reaction vessel. 3) Fine-sized silver halide grains are mixed with an aqueous solution of a water-soluble silver salt and a water-soluble halide in a mixer provided outside a reaction vessel in which nucleation and/or crystal growth of photosensitive silver halide grains occurs. 2. The photosensitive silver halide grains are formed by mixing an aqueous solution thereof, and are supplied into the reaction vessel immediately after formation to provide for nucleation and/or crystal growth of the photosensitive silver halide grains. Silver halide photographic material according to 2. 4) The silver halide photographic material according to claim 2 or 3, characterized in that an oxidizing agent and/or an inhibitor are further present under conditions that allow reduction sensitization. 5) The silver halide photographic material according to claim 2, 3 or 4, wherein the silver iodobromide has a silver iodide content of 3 mol% or more and 40 mol% or less. 6) The silver halide photographic material according to claim 2, wherein the halogen composition is silver chlorobromide, silver chloroiodide, or silver chloroiodobromide. 7) A method for producing a silver halide photographic material having at least one silver halide emulsion layer on a support,
Fine-sized silver halide grains prepared in advance are added to a reaction vessel in which nucleation and/or crystal growth of the photosensitive silver halide grains contained in the silver halide emulsion layer is caused. A method for producing a silver halide photographic material, characterized in that the grains are obtained by nucleation and/or crystal growth in the reaction vessel, and the grains are reduction sensitized. 8) A method for producing a silver halide photographic material having at least one silver halide emulsion layer on a support,
The photosensitive silver halide grains contained in the silver halide emulsion layer are placed in a reaction vessel in which nucleation and/or crystal growth of the grains is caused, and fine-sized silver halide grains prepared in advance are reduced. 1. A method for producing a silver halide photographic light-sensitive material, which is obtained by adding nucleation and/or crystal growth in the reaction vessel under conditions capable of sensitization. 9) Fine-sized silver halide grains are mixed with an aqueous solution of a water-soluble silver salt and a water-soluble halide in a mixer provided outside the reaction vessel in which nucleation and/or crystal growth of photosensitive silver halide grains occurs. Claim 7 or 7, wherein the photosensitive silver halide grains are formed by mixing an aqueous solution thereof, and are supplied into the reaction vessel immediately after formation to provide for nucleation and/or crystal growth of the photosensitive silver halide grains. 8. The method for producing a silver halide photographic material according to 8. 10) The method for producing a silver halide photographic material according to claim 8 or 9, characterized in that an oxidizing agent and/or an inhibitor are further present under conditions that allow reduction sensitization. 11) Claim 8, 9 or 1, characterized in that the silver iodobromide has a silver iodide content of 3 mol% or more and 40 mol% or less.
The method for producing a silver halide photographic material according to 0. 12) The method for producing a silver halide photographic material according to claim 8, 9 or 10, wherein the halogen composition is silver chlorobromide, silver chloroiodide, or silver chloroiodobromide.