JP2779719B2 - Silver halide emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to silver halide (hereinafter "AgX") emulsions useful in the field of photography, and more particularly to AgX emulsions containing novel shaped AgX grains.

[0002]

2. Description of the Related Art In order to increase the photographic sensitivity of an AgX emulsion, it is preferable that the number (number / cm ² ) and locations of chemically sensitized nuclei generated per AgX grain be limited. It is because the photoelectrons generated in the AgX particles have one A
This is because if a latent image is formed by many chemical sensitization nuclei in the gX grains, the latent image is dispersed and the sensitivity is not high. For this purpose, for example, using a tetradecahedral AgX normal crystal particle,
A method for preferentially forming a chemical sensitizing nucleus on a 1} surface or a {100} surface is disclosed. For example, a method of forming a chemical sensitization nucleus preferentially on one crystal plane by utilizing a difference in reactivity of a sulfur sensitizer to those crystal planes, and a method of forming a chemical sensitization nucleus on one of the crystal planes An adsorbent that is preferentially adsorbed (a surface-selective adsorbent) is added, and a crystal surface where the adsorbent is adsorbed at a high density (hereinafter referred to as a B surface) and a crystal surface where the adsorbent is adsorbed loosely (hereinafter referred to as A) After the formation of the surface, a chemical sensitizer is added thereto to chemically sensitize, and a chemical sensitization nucleus is preferentially formed on the crystal surface on which the adsorbent is loosely adsorbed. In this regard, European Patent 302,528
A2, Journal of Photographic Science, Vol. 23, 249-256 (1975), JP-A-64-74540, JP-A-58-113928, JP-A-64
No. 62631, No. 64-40938, Journal of the Photographic Society of Japan, 47, 255 (1984), FIG.
6033, 2-34 and 1-158425. However, in the case of the tetradecahedral particle, eight equivalent {111} planes and 6
Because of having the {100} faces, the location of the formation of the chemical sensitizing nucleus is insufficiently limited. Accordingly, the appearance of AgX emulsion grains in which the number of chemical sensitizing nucleus formation sites is reduced and the dispersion of the latent image is prevented is awaited.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an AgX emulsion containing AgX grains which can further prevent latent image dispersion and provide high sensitivity and high image quality.

[0004]

According to the present invention, there is provided a silver halide emulsion having at least a dispersion medium and silver halide grains, wherein at least 20% of the total projected area of all silver halide grains is cubic. Out of the eight vertices, an octahedron in which two opposite vertices are missing to form a missing face of a triangle, and the outer surface of the missing part is a {111} face,
In addition, the outermost surface has a shape in which the maximum flat part is a {100} plane, and silver halide grains having 60% or more of the total projected area of the silver halide grains having the shape are twins parallel to the triangular plane. A silver halide emulsion having two surfaces.

[0005] Preferred embodiments of the present invention are as follows. (1) The silver halide emulsion as described above, wherein the surface layer in contact with the {100} plane of the silver halide grains and the surface layer in contact with the {111} plane have substantially the same halogen composition. (2) The silver halide emulsion as described above, wherein the surface layer in contact with the {100} plane of the silver halide grains and the surface layer in contact with the {111} plane have substantially different halogen compositions.

(3) The above {111} of the silver halide grains
The above silver halide emulsion wherein a chemical sensitization nucleus is preferentially formed on the surface. (4) The above silver halide emulsion wherein the silver halide grains have a monodispersed grain size distribution.

First, the structure of the AgX particles of the present invention will be described in detail, and then the method for producing the particles will be described in detail. (A) AgX Particle Structure When the AgX particle shape of the present invention is illustrated in a perspective view, FIG.
This is shown in FIG. In other words, the cubic particle is a decahedron in which only two vertices at a relative angle are missing from the eight vertices. The shape of the crystal plane of the missing part is an equilateral triangle, and the two triangles are parallel to each other. The triangular surface is a {111} plane. This is because the equilateral triangular pyramid is missing from the corner of the cube, so that it is necessarily a {111} plane in the NaCl type crystal structure. A top view when the {100} plane of the particles is oriented on the substrate is shown in FIG.

The extent of the missing portion will be described with reference to FIG. 1B. X / y = 0.05 to 0.72, preferably 0.06 to 0.6, more preferably 0.08. ~ 0.
5, more preferably 0.1 to 0.4. in this case,
[Area of one {100} plane of the particles (y ² −x ² /
2)> relationship of the one area of the triangle ⁽³ 0.5 ^x 2/2)] is established. Therefore, the largest crystal plane (principal plane) of the grain is a {100} plane. Other corners of the cubic particles are substantially not missing. Here, “substantially” means 1.5z <x, preferably 3z <x, and more preferably 5z <x in FIG. 1B. x is the length of the missing portion of the cube, and z means the length of the deformation or defect that can exist at a vertex that is not the missing portion. The AgX emulsion grains of the present invention account for at least 20%, preferably 50%, of the projected area of all AgX grains.
% Or more, more preferably 80% or more, and still more preferably 9% or more.
0% or more are particles having the above structure.

The AgX emulsion grains of the present invention have parallel twin planes inside the grains in view of the production process. The number of the parallel twin planes is two or more, and the number of the two grains is preferably 60% or more, more preferably 80% or more, and still more preferably 90% or more of the projected area of the AgX particles having the shape. More preferably, it occupies. The particle size of the AgX particles of the present invention is a circle-equivalent projected particle diameter of 0.2 to 5 μmφ, preferably 0.3 to 3 μm. Here, the circle-equivalent projected particle diameter refers to the diameter of a circle having an area equal to the projected area of the particle when the particle is observed with an electron microscope. The Ag
The particle size distribution of the X particles is preferably monodisperse, and the coefficient of variation is preferably 30% or less, more preferably 20% or less, even more preferably 10% or less.

The first aspect of the grains of the present invention has the above-mentioned features, and refers to the case where the {100} surface layer and the {111} surface layer have substantially the same halogen composition. Here, “substantially” refers to the difference in iodine content of the surface layer (iodine content difference <2 mol%). The Cl ^- content difference or Br ^- content difference (X) indicates (X <7 mol%). The second embodiment of the AgX particles of the present invention refers to the case where the {100} surface layer and the {111} surface layer have substantially different halogen compositions. Here, “substantially” means that the difference in iodine content of the surface layer is 2 mol% or more, preferably 3 to 40 mol%, more preferably 5 to 30 mol%.
Point to. Further, the Cl ^- content difference or the Br ^- content difference (X) indicates 7 mol% or more, preferably 10 mol% or more.

The particles of the second embodiment are classified into the following two types. 1) I ^{− of} {111} surface layer compared to {100} surface layer
Content: lower aspects, and / or Cl ^- content: high aspect. In this case, the I ⁻ content of the {111} surface layer is preferably 7 mol% or less, more preferably 5 mol% or less. 2) {100} as compared to the surface layer {111} surface layer I ^-
Content: high aspect and / or Cl ^- content: less manner. The surface layer referred to in the present invention refers to a crystal layer of 2 lattices, preferably 5 lattices from the surface. Of course, it may be different for layers having a greater thickness. That is, the thickness of the heterogeneous AgX composition layer laminated on the {111} plane in FIG.
Preferably at least 5 lattices, more preferably 10 to 400
It is a lattice.

This second embodiment can be obtained by laminating an AgX layer having a halogen composition different from that of the host grains on the {111} plane of the host grains having the shape shown in FIG.
The change in the halogen composition between the host portion and the laminated portion is gradually increasing,
Any of a gradual decrease type and a steep type may be used, and can be used properly according to the purpose of use. As the halogen composition change increases, defects such as dislocations are introduced into the interface, and the formation of a latent image near the defects is promoted, which is preferable. Examples of the host particle include a core / shell type double structure particle having a different halogen composition between a core portion and a shell portion, and a multi-structure particle having a core portion and one or more shell portions, in addition to a uniform composition type.
The halogen composition change between these layers may be any of a gradually increasing type, a gradually decreasing type, and a steep type, and can be used properly according to the purpose of use.

When the AgX grains are used for a negative type or a color reversal type (external or internal type), it is preferable that a chemical sensitizing nucleus is preferentially formed on the {111} plane. Here, the priority is defined as [density of chemical sensitization nuclei on {111} plane (number /
cm ² )] / [density of chemical sensitizing nuclei on {100} plane (number / c
m ² )] = Y is preferably 2 or more, more preferably 3 or more.
Above, more preferably 5 or more. It is difficult to observe this ratio directly. However, exposure [1 second exposure. Exposure was 2 hours with MAA-1 developer.
An exposure amount that gives a density of (maximum density−minimum density) × １ ／ when development is performed at 0 ° C. for 10 minutes to an exposure amount of 10 times the exposure amount. Then, a latent image is formed on the chemically sensitized nucleus (photosensitive nucleus), suppressed development is performed, the suppressed development nucleus is made visible by electron microscope observation, and the number of the suppressed development nucleus is counted. The above ratio of the chemical sensitizing nucleus can be determined. See DC Birch et al., Journal of
Photographic Science, vol. 23, pp. 249-256 (1
975) and JP-A-64-62631. Here, the chemical sensitization nucleus is a chemical sensitization nucleus composed of sulfur, selenium, tellurium, gold and a Group 8 noble metal compound alone or in combination, and most preferably (gold-sulfur and / or selenium, tellurium sensitization nucleus) ). For details, reference can be made to the description in the literature described below. In this case, it is preferable that the inside and / or the surface of the host particle is reduction-sensitized.

When the AgX particles are used for pre-reversal type direct reversal photography, fog nuclei are preferably formed preferentially on the {111} plane. Here, the priority is [｛1
Density of fog nuclei on 11｝ plane (number / cm ² ) / {100}
The density of fog nuclei on the surface (number / cm ² )] is preferably 2
The above refers to 3 or more, more preferably 5 or more. Observing this ratio directly is difficult. However, it can be determined by suppressing the development of the AgX emulsion-coated material and observing the suppressed development nuclei by the aforementioned method. In the case of the particles, it is preferable that the inside and / or the surface of the host particles are not reduction-sensitized.

In these grains, the sensitizing dye is # 1 of the grains.
It is more preferable to preferentially adsorb on the 00 ° plane. Here, preferentially means that [the density of the adsorbed dye on the {100} plane (number of molecules / cm ² ) / the density of the adsorbed dye on the {111} plane (number of molecules / cm ² )] is preferably 2 or more, Preferably 3 or more, more preferably 5 or more. In the second mode, the mode 1) is more preferable. This is because the developing speed is higher because the latent image is formed on the laminated portion.

(B) Method for producing AgX emulsion The method for producing the AgX emulsion of the present invention basically comprises a tabular seed crystal forming step, a crystal growing step and a chemical sensitizing step. Next, each process will be described in detail. 1) Step of Forming Tabular Seed Crystals To prepare the grains of the present invention, first, tabular grains having parallel twin planes are prepared and used as seed crystals. A conventional AgBrI (I ^- content is 0 mol% to solid solution limit) tabular grain forming method is disclosed in JP-A-58-113926-1.
No. 13928 can be referred to. on the other hand,
Regarding the method of forming parallel double twin tabular grains having good monodispersibility, JP-A-63-11928 and JP-A-63-151618 disclose
JP-A-1-131541, JP-A-2-838, JP-A-2-28
No. 638 and Japanese Patent Application No. 1-302790 can be referred to.

Briefly, the nucleation process →
It is formed through an aging process. The nucleation is carried out in an aqueous solution containing a dispersion medium while maintaining the pBr at 2.5 or less, preferably 1 to 2.5, with an aqueous silver salt solution and a halide salt (hereinafter referred to as X ^- salt).
Nucleation is performed by adding an aqueous solution. Gelatin concentration at the time of frequency different supersaturation factors [nucleation twin planes during nucleation is formed, the molecular weight of the gelatin, the addition rates of silver salt and halide salt solution, Br in the reaction solution ^-, I
^-, Cl ^- concentration, stirring rotational speed, I in aqueous halide salt solution to be added ^- content, AgX solvent concentration, temperature, regardless salt concentration, nucleation period, depending on the pH or the like], some of its dependencies Is shown in the drawing of JP-A-63-92942. When the twin plane formation probability is too high, the abundance ratio of triple or more multiple twin particles or non-parallel double twin particles in the ripened seed crystal increases. Therefore, while observing the dependence of these figures, the supersaturation factor may be adjusted so as not to be too high and not too low so as to increase the ratio of the parallel double twin particles in the seed crystal.

The nucleation period is preferably 6 minutes or less, more preferably 3 minutes or less, and even more preferably 1 minute or less. After such nucleation, the pBr is then reduced to 2.0 or less, preferably 1
The first aging is performed at a temperature of 50 ° C. or higher, preferably 60 ° C. or higher. Thereby, non-tabular grain nuclei generated during nucleation are eliminated. After the first ripening, the next crystal growth process can be started, but it is more preferable to further perform the second ripening to completely eliminate the non-tabular grains. In the second aging, after the first aging, an AgNO ₃ solution is added to raise the pBr to 0.1 or more, preferably 0.3 or more, and to make the pBr preferably 1.7 or more, more preferably 1.8 to 3. And mature. An AgX solvent can coexist at the time of the aging, particularly at the time of the second aging. The following description can be referred to as the AgX solvent. AgX solvent addition amount is 0
０．３0.3 mol / l, preferably 10 ^-4 ０．３0.3 mol / l.

[0019] Cl ^- Patent regard method of forming tabular grains having a high content of parallel twin planes 2-32, JP 63
-281149, 63-218938, 64-72
142, 58-111936, Journal of Imaging Science, 34, 44-50 (199
0), ibid., 33, 13-17 (1989), Journal of Photographic Science, 36, 1
82-186 (1988). The higher the pBr during the second ripening and the higher the concentration of the AgX solvent coexisting at that time, the thicker the tabular grains produced and the aspect ratio (projected grain size / thickness).
Will be lower. In this way, a seed crystal including a parallel twin plane is formed. At the time of the second aging or after the second aging, a third
A ripening step is provided, and the pBr value is at least 2.1, preferably 2.
The particles of the present invention can also be formed by selecting three or more optimum values. The optimum value depends on the halogen composition of the particles, the type and concentration of the AgX solvent, the particle size, and the like. pB
The higher the r-value and the higher the concentration of the AgX solvent, the closer to a perfect cubic particle. However, many then enter the crystal growth process.

2) Crystal Growth After forming a seed crystal including parallel twin planes in this manner, (i) crystal growth is subsequently performed in a cubic or tetradecahedral particle generation region. More specifically, in the case of AgBr, the optimum value can be selected by a tri-and-error method while observing the particle shape with a pBr of preferably 2.1 or more, more preferably 2.3 or more. The optimal value is the halogen composition of the particles, A
It depends on the type and concentration of the gX solvent, the degree of supersaturation during growth, the particle size, and the like. The higher the pBr value and the higher the concentration of the AgX solvent, the closer to a perfect cubic particle.

(Ii) After the seed crystal is further grown with pBr <2.1, an optimum value of pBr2.1 or more, preferably 2.3 or more is selected and grown. How to select the optimal value is described in (i) above.
Is the same as In these cases, uniform composition type host particles can be obtained by making the halogen composition of the seed crystal part and the growth part the same. On the other hand, core / shell type double structure grains and multiple structure grains can be obtained by making the halogen composition of the seed crystal part and at least a part of the growth part different. Reduces, ^- excess Br by To (washing of the emulsion, or the addition of AgNO ₃ ^- The Cl during the growth ^- the excess halide ions in the reaction solution when to stack AgX layer containing Cl
Cl ^- salt may be added), and a silver salt solution and an X ^- salt solution may be added.

(Iii) After the seed crystal is further grown with pBr <2.1, it is aged by selecting an optimum value of pBr2.1 or more, preferably 2.3 or more, to obtain the particles of the present invention. The method of selecting the optimum value is the same as the above-mentioned aging. In order to form the particles of the second embodiment of the present invention, AgX layers having different halogen compositions are selectively laminated on the {111} surface of the particles having the shape of FIG. 1 thus formed. I just need.

This plane-selective crystal growth is performed by adjusting the supersaturation S and pAg of the reaction solution during the crystal growth. Now, the chemical potentials of Ag ⁺ on the {100} surface and the {111} surface are μ ₁₀₀ and μ ₁₀₀ , respectively.
The chemical potential of Ag ^{+ in} the solution when ₁₁₁ and the silver salt and the X ⁻ salt are added to this system is μ _Ag ⁺ . In this case, the addition is performed by adding a silver salt and X ⁻ with S and pAg satisfying μ ₁₀₀ > μ _Ag ⁺ > μ ₁₁₁ , more preferably μ ₁₀₀ >> μ _Ag ⁺ > μ ₁₁₁ . μ _Ag ⁺ and S are related by μ _Ag ⁺ = kTlnS (where k = Boltzmann constant, T = absolute temperature). The condition of μ ₁₀₀ > μ ₁₁₁ can be obtained by adjusting the conditions of the emulsion to the above-mentioned cubic grain formation conditions. For example, when the tetradecahedral particles are placed in a solution of pAg in the cubic particle generation region, μ ₁₀₀ > μ ₁₁₁ is satisfied.

When forming surface layers having different halogen compositions, it is not preferable that Ostwald ripening occurs between layers and between grains. Therefore, the temperature at that time is preferably low, preferably 70 ° C. or less,
-30 ° C is more preferred. In addition, it is preferable that the adsorbent described below is adsorbed immediately after crystal growth to prevent Ostwald ripening between the layers.

In addition to the particles of the present invention, the layered portion of the second aspect is further grown, and the x / y is set to 0.01 <x
/Y<0.05, preferably 0.02 to 0.05. That is, the missing portion is almost completely filled with an AgX layer having a halogen composition different from that of the host grains. However, after the missing part is filled,
Since the added solute is laminated on the {100} plane, it is preferable to stop the addition of the solute before filling.

3) Chemical sensitization In the present invention, it is preferable to form a chemical sensitization nucleus preferentially on the {111} surface or on the surface of the laminated portion. This method is disclosed in European Patent 302528A2,
Nos. 4-74540 and 64-62631;
No. 34, No. 1-158425, No. 1-220161
No. 2-146033, 2-838, 2-28
638, 2-298935, Japanese Patent Application No. 3-11587
2, 3-73266, Journal of Photographic Science, 23, 249-256 (19
75) can be referred to. Briefly, it is as follows. A more selectively reacting chalcogen sensitizer is reacted on the {111} surface than on the {100} surface like hypo. Thereby, {111}
Emulsion grains of the present invention having chalcogen sensitizing nuclei formed preferentially on the surface can be formed.

Next, when a gold sensitizer is added to the emulsion and ripened to form a gold-chalcogenide sensitizing nucleus, it is preferable to reduce the amount of unreacted residual chalcogen sensitizer. This is because the priority often decreases. Specifically, (i) the added chalcogen sensitizer, preferably 7
It is added after 0% or more, more preferably 85% or more has reacted. (ii) added after removing unreacted chalcogen sensitizer. Specifically, an additive that removes the emulsion by washing with water or reacts with an unreacted chalcogen sensitizer and invalidates it (for example, a method of lowering the pH of the emulsion with HNO ₃ or the like, a method of adding an oxidizing agent, ), And removal using an adsorbent (activated carbon, ion exchange resin, chelating agent, etc.). Thereby, (amount of unreacted chalcogen sensitizer / amount of added chalcogen sensitizer)
Is preferably reduced to 0.3 or less, more preferably 0.15 or less. When the pH is lowered and invalidated, the pH may be returned to the original value. When an oxidizing agent is added, it may be added in a necessary amount. Examples of the oxidizing agent include H ₂ O ₂ , oxyacids, peroxides, and metal and nonmetal oxides. Regarding the adsorbent, the description of Japanese Patent Application No. 3-73266 can be referred to.

After the adsorbent preferentially adsorbing on the {100} face is adsorbed, a chemical sensitizer is added to form a chemical sensitizing nucleus preferentially on the {111} face. In this case, when the above methods are used together, the priority is further increased,
preferable. In the case of the grains of the second embodiment, the location where the chemical sensitization nucleus is formed is limited by utilizing the difference in halogen composition between the host portion and the surface of the laminated portion in addition to the crystal habit difference. That is, after the adsorbent is preferentially adsorbed on the surface of the host portion, chemical sensitization is performed, and a chemical sensitization nucleus is preferentially formed on the surface of the laminated portion. Here, the preferential adsorption means (number of molecules of adsorbent adsorbed on the {100} face of the host particles / cm ² ) / (number of molecules of adsorbent adsorbed on the layered portion of the particles / cm ² ). Preferably 2 or more, more preferably 3
Above, more preferably 5 to 15. The $ 11
The adsorbent is also adsorbed on the {1} face, and the number of chemical sensitizing nuclei / cm ² on the {111} face can be limited.

In these cases, the adsorbent is a sensitizing dye,
Antifoggants, dimer or higher polymers thereof, and pendant dyes (refer to European Patent 372,573A2) can be used. Two or more adsorbents can be added.
Such selective adsorbents can be selected by examining the adsorption isotherm curves of various adsorbents for various AgX emulsion grains having the same grain surface area but different halogen composition or crystal habit. Adsorption force is usually the adsorption free energy (△
G) and can be conveniently determined from a Langmuir adsorption isotherm.

The following method is effective as a simple method. For comparison, two or more AgX emulsions (A, B...) Are dissolved and mixed. Under the conditions to be compared (pH, temperature, pA
g), two or more emulsion-coated films (films independently coated with AgX emulsions of A, B,...) are immersed. A sensitizing dye is added thereto, and after reaching the adsorption equilibrium, the coated film is taken out. The attached emulsion can be washed away with water, and the amount of dye adsorbed on the emulsion can be determined by the Kubelka-Munk method, or the sample can be placed in an integrating sphere to determine its selective adsorption. If n types of emulsion-coated films are included, the amount of adsorption equilibrium between the n types of emulsions can be determined. In addition, the description of JP-A-64-40938 can be referred to.

Examples of dyes which are more likely to be selectively adsorbed on the {100} face than on the {111} face include: E-1) 3,3′-bis (4-sulfobutyl) -9-meth
yl-thiacarbocyanine pyridinium salt E-2) 5,5′-diphenyl-9-ethyl-3,
3'-di (2-sulfoethyl) -oxacarbocyanine Na salt E-3) 5-chloro-5'-phenyl-9-ethyl-
3- (3-sulfopropyl) -3 ′-(2-sulfoethyl) oxacarbocyanine Na salt E-4) 5,5′-dichloro-9-ethyl-3,3 ′
-Di (3-sulfopropyl) oxacarbocyanine Na
Salt E-5) 5,5′-dichloro-6,6′-dichloro-
1,1′-diethyl-3,3′-di (3-sulfopropyl) imidacarbocyanine Na salt E-6) 5,5′-diphenyl-9-ethyl-3,
3'-di (3-sulfopropyl) thiacarbocyanine N
a salt.

The dependence of the selective adsorption on the halogen composition is as follows. Generally, the adsorption strength of cyanine dye is A
gCl <AgBr <AgBrI. On the other hand, the adsorptivity of the anti-fogging agent and the merocyanine dye having an affinity for Ag ⁺ is opposite, that is, AgCl> AgBr <AgBr. Specific examples of this cyanine dye include 1,1′-diethyl-
2,2-cyanine chloride, 1,1 ', 3,3'-tetramethyl-2,2'-cyanine, anionic 9-methylthia-carbocyanine, 5,5'-phenyl-9-
Ethyl-3,3 ′-(2-sulfoethyl) oxacarbocyanine pyridinium salt, Dye1 (5,5-dichloro-9-ethyl-3,3 ′-(3-sulfopropyl) oxacarbocyanine sodium salt, and Next Dye2
And Dye3 and said E-3 can be mentioned.
Among them, Dye1 is preferable because the iodine content dependency of adsorption is particularly large. The following documents can be referred to for specific examples of other cyanine dyes.

[0033]

Embedded image

The antifoggant is generally expressed in the acid form (HL), and its solubility product pKsp (AgL) =-log [Ag ⁺ ].
[L ^-] and when compared AgX of pKsp the (AgX), [pKs
The larger the value of p (AgL) -pKsp (AgX)] = pK, the more strongly the surface of the AgX particles is adsorbed. The pKsp value of the antifoggant is preferably 9.5 or more at 25 ° C., more preferably 10.5 or more.

As a specific example, 1-phenyl-5-mercap
totetrazole (pKsp16.2), 5-methylbenzo-triazo
le (13.6), benzotriazole (13.5), 5,
6-dimethylbenzo-triazole (12.7), 5-brom
obenzo-triazole (12.7), 4-nitro-6-chlo
robenzotriazole (same as 11.2), 2-mercapto-4-me
thyl-6,6'-dimethylpyrimidine (same as 14), 5
-Nitrobenzotriazole (11.8), benzimidazole
(11.5), 2-methylbenzimidazole (12.
2), 4-hydroxy-6-methyl-1,3,3a, 7-
tetraazaindene (10-11).

For other specific examples, the description in the following literature can be referred to. Examples of the merocyanine dye include the following formulas (M1) to (M4).

[0037]

Embedded image

Here, R ¹ , R ² , R ³ : H, preferably a substituted or unsubstituted alkyl group having 18 or less carbon atoms,
An aryl group, and as the substituent, a carboxy group, a sulfo group, a cyano group, a halogen atom, a hydroxy group, an alkoxycarbonyl group, an alkoxy group, a monocyclic aryloxy group, an acyloxy group, an acyl group, a carbamoyl group,
And a sulfamoyl group and an aryl group. X: O, N, S, Se, Y: O, S, Se, n = 0,
1, 2, 3, and 4.

The adsorption power of these sensitizing dyes and antifoggants to AgX grains depends on the various habits of the emulsion (emulsion pH, pAg,
And the like in the presence of an adsorption promoter.
Therefore, it is possible to adjust the adsorption strength of the sensitizing dye or the antifoggant by utilizing the knowledge. For example, the antifoggant is preferably adsorbed under conditions of a pH of (the pKa-1) or more. Here, Ka is an acid dissociation constant of the antifoggant. In general, the sensitizing dye is more likely to form J aggregates as the adsorptive power becomes stronger. J-aggregates are preferred because they more fully prevent the formation of chemical sensitizing nuclei. The amount of the adsorbent used is 15 to 180 of the saturated adsorption amount.
%, Preferably 20 to 100%. In addition, the adsorbent can be used as a function-separated type described in JP-A-1-201651 and Japanese Patent Application No. 3-73266.

The amount of the sulfur sensitizer incorporated into the AgX particle phase is 10 ^-9 to 10 ^-3 mol / mol AgX, preferably 10 ^-8 to 10 ^-4 mol / mol AgX. As a gold sensitizer, a gold complex salt (for example, US Pat. No. 2,399,083)
Can be preferably used. More specifically, chloroauric acid, alkali metal chloroaurate, sodium or potassium aurithiocyanate, auric trichloride, sodium aurithiosulfate, and auric-5-sulfobenzothiazole-2-sulfide chloride can be exemplified. . The incorporation amount of the gold sensitizer into the AgX particle phase is 10 ^-9 to 10 ^-3 mol / mol Ag.
X, preferably 10 ^-8 to 10 ^-4 mol / mol AgX.

Other conditions for producing the AgX emulsion of the present invention include the following. In order to prevent the adsorption state of the adsorbent from changing during the chemical ripening, the adsorption of the adsorbent is preferably performed at a temperature of 5 ° C. or higher than the temperature during the next chemical ripening.
More preferably at a high temperature of 10 ° C. or higher, and preferably 5 ° C.
It is preferable to spend more than a minute. Chemical ripening is performed at a low temperature (preferably 55 ° C. or lower, more preferably 30 to 50
C). Normally, the face-selective reactivity of a chalcogenide sensitizer is larger under the low temperature and high pAg conditions (pAg> 8). Also, the selective adsorbability of the adsorbent becomes larger under the low temperature condition. The decrease in the chemical ripening reaction rate due to the low temperature can be recovered by reducing the pAg of the emulsion to preferably 8 or less, more preferably 7.5 to 5.

(C) Others AgX fine particles (AgCl, Ag) of 0.1 μmφ or less which can be deposited on the particles during or after chemical ripening.
Br, AgI and a mixed crystal of two or more of them). The chemical sensitizing nucleus is preferable because it is made latently shallow. Chemical ripening can also be carried out in the co-presence of an SCN ^- salt, an S-containing compound, and a ripening accelerator (AgX solvent). Regarding these prior arts, the description in the following literature can be referred to.

The silver ions and X to be added to the crystal growth period ^- as a method of adding ions silver salt solution and the X ^- method of adding a salt solution, pre 0.1μmφ following size ultrafine emulsion (AgCl, AgBr, AgI And / or a mixed crystal thereof) or a combination thereof. Also, a method of increasing the rate of adding these solutes during crystal growth can be used.
These can also be added through a porous material.
These are disclosed in JP-A-2-14633 and JP-A-3-21.
339, Japanese Patent Application Nos. 2-326222, and 2-14263
5, 2-43791 can be referred to.

An AgX solvent can be used to promote ripening during the physical ripening process, to promote growth during the crystal growth process, to promote chemical ripening, and during nucleation. Thiocyanate as the AgX solvent used,
Antifoggants such as ammonia, ammonium salts, thioethers, thioureas, and tetrazaindene compounds, and organic amine-based compounds. In this regard, it is possible to refer to the description in the literature described below. In the present invention, the grains may be used as a core to form a shallow inner latent emulsion. The latent image is preferable because it is protected from the outside world and stabilized by the AgX layer. In this regard, reference can be made to the descriptions in JP-A-59-133542 and JP-A-63-151618, and U.S. Patent Nos. 3,206,313 and 3,317,322.

The silver halide grains of the present invention can be used as emulsions by themselves, but the grains may be used as a core to form a core / shell type direct reversal emulsion, which may be used. This is described in
No. 151618 and Example 13 thereof, US Pat.
No. 61,276, No. 4,269,927, No. 3,
No. 367,778 can be referred to. Further, the core / shell type direct reversal emulsion is disclosed in JP-A-60-95533.
It can be preferably used as a constituent emulsion in the examples of the present invention. Also, raffled particles can be formed using the particles as substrate particles. For this, reference can be made to U.S. Pat. No. 4,643,966. In addition, particles having dislocation lines therein can be formed using the particles as a core or during the formation of the particles. This is described in JP-A-63-220238 and JP-A-3-163433.
Can be referred to. In addition, epitaxial particles can be formed using the particles as host particles. In this regard, reference can be made to the descriptions in Journal of Imaging Science, Vol. 32, 160-177 (1988) and the literature described below.

The sensitizing dye used as the adsorbent and the spectral sensitizing dye of the present invention includes a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye,
Polymethine dyes including holopolar cyanine dyes, hemicyanine dyes, styryl dyes, hemioxonol dyes, oxonol melostyril and streptocyanin,
Pendant dyes can be mentioned. However, A before application
In the gX emulsion, it is more preferable that the sensitizing dye is preferentially adsorbed on the {100} face rather than on the {111} face. As a spectral sensitizing dye, a sensitizing dye that preferentially adsorbs on the {100} plane may be added. Specific examples of the dye include the above-mentioned E-1) to E-6).
Here, the preferential adsorption means (number of molecules of adsorbent adsorbed on the {100} face of the host particles / cm ² ) / (number of molecules of adsorbent adsorbed on the layered portion of the particles / cm ² ). The number is preferably 2 or more, more preferably 3 or more, and still more preferably 5 to 15. The particles can also be spectrally sensitized with an antenna dye. In this regard, the descriptions in JP-A-63-138341 and JP-A-63-138342 can be referred to.

Examples of the antifoggant used as the adsorbent and the antifoggant include tetrazaindenes and azoles such as benzothiazolium salts, nitroindazoles, nitrobenzimidazoles, chlorobenzimidazoles, Bromobenzimidazoles, mercaptothiazoles, mercaptobenzimidazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazole (especially 1-phenyl-5-mercaptotetrazole), etc., mercaptopyrimidines, mercaptotriazine Thioketo compounds such as oxazolythion, benzenethiosulfinic acid, benzenesulfinic acid, benzenesulfonamide, hydroquinone derivatives, amino Phenol derivatives, gallic acid derivatives, and ascorbic acid derivatives.

The dispersion medium used in the present invention is AgX
Any known dispersion medium for an emulsion can be used. Usually, gelatin is preferred, and alkali-treated gelatin from which impurity ions and impurities have been removed is more preferred. As the gelatin, in addition to alkali-treated gelatin, acid-treated gelatin, derivative gelatin such as phthalated gelatin, low molecular weight gelatin (molecular weight of 1,000 to 100,000, specifically gelatin decomposed by enzymes, hydrolyzed by acid and / or alkali Gelatin, heat-decomposed gelatin), high molecular weight gelatin (molecular weight of 100,000 to
300,000), gelatin having a methionine content of 50 μmol / g or less, oxidized gelatin, and gelatin in which methionine is inactivated by alkylation or the like can be used.
A mixture of two or more of them can also be used.

In addition, it can be used in combination with any conventionally known technique. In this regard, the description in the following literature can be referred to. There are no particular restrictions on the additives that can be added during the production of the silver halide emulsion of the present invention from the time of grain formation to the time of coating. Additives that can be added are silver halide solvents (also called ripening accelerators),
Doping agent for silver halide grains [Group 8 noble metal compound,
Other metal compounds (gold, iron, lead, cadmium, etc.), chalcogen compounds, SCN compounds, etc.), dispersion media, antifoggants, stabilizers, sensitizing dyes (blue, green, red, infrared, panchromatic,
For orthophoto), supersensitizer,

Chemical sensitizers (sulfur, selenium, tellurium, gold and Group VIII noble metal compounds, phosphorus compounds alone or in combination, most preferably gold,
Chemical sensitizers consisting of a combination of sulfur, selenium and tellurium compounds, reduction sensitizers such as stannous chloride, thiourea dioxide, polyamines and amine borane compounds, fogging agents (organic fogging agents such as hydrazine compounds ( Inorganic fogging agent), surfactant (antifoaming agent, etc.), emulsion sedimentation agent,
Soluble silver salt (AgSCN, silver phosphate, silver acetate, etc.), latent image stabilizer, pressure desensitization inhibitor, thickener, hardener, developer (hydroquinone compound, etc.), development modifier, color image formation Agent,
These are color photographic additives and the like, and specific compounds and methods of use can be referred to the descriptions in the following documents.

In addition, regarding the steps of grain formation, washing of emulsion, chemical sensitization, spectral sensitization, coating, exposure, and development, and the layer constitution of AgX emulsion coating, preservation method of coating, etc., the following documents: And any combination of known techniques and known compounds.

The silver halide emulsion produced by using the apparatus of the present invention is a black-and-white silver halide photographic material [for example, X
Lay material, printing material, photographic paper, negative film, microfilm, direct positive material, ultra fine particle dry plate material (LSI
Photomasks, shadows, and liquid crystal masks)], and color photographic materials (eg, negative films, photographic papers, reversal films, direct positive color photographic materials, silver dye bleaching photographs, etc.). Further, a photosensitive material for diffusion transfer (for example, a color diffusion transfer element, a silver salt diffusion transfer element),
Photothermographic materials (black and white, color), high-density digital recording materials, holographic materials, and the like can also be used. Regarding these details, the description in the following literature can be referred to.

Research Disclosure (Research Di
sclosure), 176 volumes (item 17643) (12
Mon, 1978), Volume 307 (Item 30710)
May, November, 1989), by Duffin, Photographic Emulsion Chemistry, Focal P
ress, New York (1966), Bill (EJ Bir
r), photographic silver halide emulsion stabilization (Stabilization o)
f Photographic Silver Halide Emulsions), Focal Press, London (1974),
James (TH James), Theory of the Photographic Process (The The
ory of PhotographicProcess) 4th edition, Macmillan (Macm
illan), New York (1977)

P. Glafkides, Chemie et Physique Photographiques, Chapter 5
Edition, edition da lysine novel (Edition del ',
Usine Nouvelle, Paris (1987), 2nd edition, Paul Monterlu, Paris (1957), Zerikman et al.
(VL Zelikman et al.), Preparation and coating of photographic emulsion (Makin
gand Coating Photographic Emulsion), Focal Press
(1964), KR Hollister, Journal of Imaging Science
aging science), volume 31, p. 148-156 (198
7 years), Maskesky (JE Maskasky), same volume 30,
P. 247-254 (1986), 32, 160
177 (1988), 33 volumes, 10-13 (198
9 years),

Freezer et al., Eds., Fundamentals of the silver halide photographic process (Die Grundlagen Der Photographischen Prozesse)
Mit Silverhalogeniden), Akademische Verlaggesellschaft,
Frankfurt (1968). JCIA Monthly Report 1984
Year, December issue, P. 18-27, Journal of the Photographic Society of Japan, 49
Vol. 7-12 (1986), Vol. 52, 144-16
6 (1989), 52, 41-48 (1989)
Year), JP-A-58-113926 to 113926, and 5
Nos. 9-90841, 58-111936, 62-9
9751, 60-143331, 60-14333
2, 61-14630, 62-6251, 63-
220238, 63-151618, 63-281
149, 59-133542, 59-45438,
62-269958, 63-305343, 59
-142539, 62-253159, 62-26
6538, 63-107813, 64-2683
9, 62-157024, 62-192036,

JP-A-1-297649 and JP-A-2-2766
35, 1-158429, 2-42, 2-246
43, 1-146033, 2-838, 2-28
638, 3-109539, U.S. Pat.
461, 4,942,120, 4,269,92
7, 4,900,652, 4,975,354, European Patent No. 0355568A2, Japanese Patent Application No. 2-36222.
2, 2-415037, 2-266615, 2-
43791, 3160395, 2-14263
5, ibid. 3-146503,

[0057]

Next, the present invention will be described in more detail by way of examples, but embodiments of the present invention are not limited thereto. Example 1 In a reaction vessel, 1200 cc of a dispersion medium solution [8.4 g of gelatin having an average molecular weight of 20,000 (20,000 Gel), 5.4 g of KBr,
pH 5.7], keeping the temperature at 30 ° C., and stirring Ag.
-1 aqueous solution (containing 20 g of AgNO ₃ in 100 cc)
And Br-1 aqueous solution (14.9 g of KBr in 100 cc, 2
(Including 0.7 g of 10,000 Gel) at a flow rate of 48 cc / min. After stirring for 1 minute, aqueous gelatin solution 168
cc (Deionized alkali-treated gelatin for photography (AGe
l) 38 g, pH 5.5) were added. After stirring for 1 minute, the temperature was raised to 75 ° C. and aged for 12 minutes. Then A
g-1 aqueous solution at 7 cc / min.
9.5 cc of ₄ NO ₃ aqueous solution (50% by weight solution), NH ₃ (2
9.5 cc (5% by weight liquid) was added, and the mixture was aged for 18 minutes. Next, an HNO ₃ (3N) solution was added to adjust the pH to 5.5.

Next, Br-2 aqueous solution (KB in 100 cc)
r14.4 g) to give pBr 1.77,
Ag-1 solution and Br-2 solution at 10 cc / min for 8 minutes, pB
r1.77 (silver potential -20 mV _vs. saturated calomel electrode). D. J was added. Next, Ag-2 solution (Ag-1
Solution having the same composition as that of the liquid), and the silver potential was adjusted to 100 mV.
g-1 solution and Br-2 solution at the potential. D. J was added.
The addition was performed for 39 minutes by a linear flow rate acceleration addition method at an initial flow rate of 13.3 cc / min. After stirring for 2 minutes after the addition, a sedimentation agent was added, the temperature was lowered, and the precipitate was washed with water by a sedimentation washing method. The emulsion was then redispersed and adjusted to pH 6.4 and pBr 2.6. FIG. 3 shows a transmission electron micrograph (TEM image) of a replica of the emulsion grains sampled at this time. The average value of x / y in the missing part of the cube was about 0.37, and y = 0.8 μm.

E-1) The aqueous dye solution was treated with a saturated adsorption amount of 7
Only 0% was added, the temperature was raised to 70 ° C., and aging was performed for 10 minutes. Next, the temperature was lowered to 58 ° C., and the Na ₂ S ₂ O ₃ solution was
After adding only 10 ^-6 mol / mol AgX and aging for 20 minutes, gold sensitizer [mixture of chloroauric acid and NaSCN solution]
Was added in an amount of 5 × 10 ⁻⁶ mol / mol AgX, followed by aging for 10 minutes. Next, the temperature is lowered to 40 ° C., and the antifoggant TAI
(4-hydroxy-6-methyl-1,3,3a, 7-tetr
aazaindene) was added in an amount of 2 × 10 ⁻³ mol / mol AgX, and then a coating aid was added to coat (the amount of silver applied was 1.5 g / mol).
m ² , the base was a polyethylene terephthalate film). The sample was designated as J1.

Example 2 After grain formation was completed in Example 1, Ag-2 solution was further added to adjust the silver potential of the emulsion to 120 mV.
Two liquids (13.4 g of KBr and 0.9 of KI in 100 cc)
150 cc was added at 18 cc / min. When the TEM image of the emulsion grains sampled at this time was observed, there was no change in the grain shape. Therefore, the AgBrI layer thus laminated was uniformly laminated on the seed crystal. Next, an HNO ₃ (3N) solution was added to adjust the pH to 4.5, and an Ag-2 solution was added.
The silver potential was set to +160 mV, and 22 cc of the Ag-2 solution and the Br-2 solution were added at 10 cc / min. Immediately after the addition, sensitizing dye E-3) was added by 70% of the saturated adsorption amount. From the observation of the TEM image of the emulsion grains sampled at this time, the added AgBr layer was selectively laminated on the {111} plane of the grains.

The temperature of the emulsion was immediately lowered to 58 ° C.
Br 2.6, Na ₂ S ₂ O ₃ solution was added in an amount of 7 × 10 ⁻⁶ mol / mol AgX, and the mixture was aged for 20 minutes. A precipitant was added to the emulsion, the temperature was lowered to 30 ° C., and the emulsion was washed with water at pH 4.0. The emulsion was redispersed, pH 6.4, pBr
2.6 and the temperature was raised to 58 ° C. 5 gold sensitizers
It was added in an amount of × 10 ⁻⁶ mol / mol AgX and aged for 10 minutes. The temperature was lowered to 40 ° C., TAI was added in an amount of 2 × 10 ⁻³ mol / mol AgX, and then a coating aid was added to coat the base with a coating amount of silver of 1.5 g / m ² . The sample was placed in J2
And

Comparative Example 1 Twinless cubes and tetradecahedral AgBr particles were formed by the method described in JP-A-2-14633. The average particle volume of both is the same as the average volume of the particles of Example 1. This makes the nucleation the same (Example 1 of JP-A-2-14633), and the C.I. D. J. Silver potential of 150mV and 90m
V and grown without generating new nuclei. The emulsion was chemically sensitized and coated under the same conditions as in Example 1. The coated sample of the cubic particles was designated as H1, and the coated sample of the tetradecahedral particles was designated as H2.

The coated samples of J1, H1, and H2 were exposed to a wedge through a blue filter for 10 ^-2 seconds, and then exposed to MAA-1 developer (described in the above-mentioned Birch document) at 20 ° C. at 10 ° C.
Minutes. The relative sensitivities determined from the obtained characteristic curves are J1 (120), H2 (110), and H1 (100).
And the high sensitivity of the particles of the present invention was confirmed. J1,
When the coated sample of J2 was exposed to blue light for 1 second and the number of suppressed development nuclei was counted by the above-mentioned method, the Y values were J1 (4) and J2 (6). The suppression effect was confirmed.

[0064]

According to the present invention, the thus obtained AgX
Emulsion grains are more limited in the locations where the chemical sensitization nuclei are formed. Therefore, the latent image dispersion is further prevented, with high sensitivity,
An AgX emulsion having excellent reciprocity characteristics, development progress, and image quality is provided. In a preferred embodiment of the present invention, the sensitizing dye is preferentially adsorbed on the {100} face, and the chemical sensitizing nucleus is preferentially formed on the {111} face. This embodiment is particularly preferable in the following points. Most of sensitizing dye compound examples (about 90% or more)
Indicates selective adsorption on the {100} plane. Therefore, there is a wide selection range of sensitizing dyes that can be used.

The adsorption part of the sensitizing dye and the latent image forming part are separated on one AgX particle surface.
The surface-separated-type chemical sensitization effect described in the above item can be obtained. In particular, when the {100} plane is a high iodine content layer, the valence band increases, and dye holes are easily injected into the valence band in terms of energy level. Then, it reacts with the reduced silver nuclei in the AgX layer, emits electrons, and contributes to sensitization. {111}
The surface has a low valence band because it is a low iodine content layer or a Cl ^-- containing layer. Therefore, the latent image existing there is hard to be attacked by dye holes and is stable. When the chemical sensitization nucleus on the {111} surface is made latently shallow, the latent image is more stabilized because it is protected from the outside world, which is preferable.

[Brief description of the drawings]

FIG. 1 shows the shape of AgX particles according to the first embodiment of the present invention.
(A) is a perspective view of the particles, and (b) is a top view.

FIG. 2 shows the structure of AgX particles according to the second embodiment of the present invention.

FIG. 3 is a 5000 × photomicrograph showing the grain structure of emulsion grains of the first embodiment produced in Example 1.

[Explanation of symbols]

 x: missing portion length on one side of the cube y: length of one side of the cube z: missing portion length on one side of the cube 1: host particle portion 2: laminated portion selectively laminated on {111} plane

Claims (5)

(57) [Claims] 1. A silver halide emulsion having at least a dispersion medium and silver halide grains, at least 20% of the silver halide grains of the total projected area of all silver halide grains, the standing side <br/> body 8 of pieces of vertices, two vertices relative corners missing
Octahedral missing plane triangle is formed, 該欠outer surface of the drop point is I {111} Mendea and maximally flat portion of the outer surface has a {100} Mendea Ru shape, and the shape Ha with
Halogenation of more than 60% of the total projected area of silver halide grains
A silver halide emulsion comprising silver grains having two twin planes parallel to the triangular plane . 2. The method according to claim 1, wherein said {100} face of said silver halide grains is
The contact surface layer and the surface layer contacting the {111} plane are substantially
2. The silver halide emulsion according to claim 1, which has the same halogen composition . 3. The method according to claim 1, wherein said {100} face of said silver halide grains is
The contact surface layer and the surface layer contacting the {111} plane are substantially
2. The silver halide emulsion according to claim 1, which has a different halogen composition . 4. The method according to claim 1 , wherein said {111} face of said silver halide grains is
The chemical sensitization nucleus is preferentially formed thereon, wherein:
3. The silver halide emulsion according to any one of the above items 3 . 5. A grain size in which said silver halide grains are monodispersed.
The silver halide emulsion according to any one of claims 1 to 4, which has a noise distribution.