JPH07119935B2 - Method for producing silver halide photographic emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a silver halide photographic emulsion spectrally sensitized with a spectral sensitizing dye, particularly, the grain surface is mainly (100).
The present invention relates to a method for producing a photographic emulsion comprising spectrally sensitized silver halide grains having a surface.

(Prior Art) Generally, a silver halide photographic emulsion is prepared through a process of forming silver halide grains by metathesis of a soluble silver salt and a soluble halide in an aqueous gelatin solution, physical ripening, desalting, and chemical ripening steps. .

The shape of silver halide grains is octahedron, cubic, 14-sided, plate-like, porcelain-like and amorphous, but the surface, that is, the crystal phase is mainly composed of (100) plane and (111) plane,
These surface ratios change depending on various conditions during grain formation. E. Moisar, E. Klein (E.
Klein), "Berichte der Bunsen Gezershyaft Huon Fuizikariszien Chemie" (Ber.Bunsen
ges.Physik.Chem.), 67,949 (1963), the ratio of the (100) face to the (111) face changes depending on the silver ion concentration of the solution at the time of grain formation, that is, pAg, and is low. The (100) plane appears in pAg, and the (111) plane appears in high pAg. For crystals of silver iodobromide
ocki), A.Zaleski, Photograph Science and Engineering (Ph)
otogr.Sci.Eng.), 17,289 (1973), the higher the concentration of ammonia as a solvent at the time of grain formation and the lower the iodine ion content, the higher the pAg at which the (100) plane appears. The same effect as ammonia can be observed with ethylenediamine (CRBerr).
y), STMarino, ST F Oster Giunia (CFOster, Jr.), Photograph Science and Engineering (Photogr.Sci.Eng.), 5: 332 (1961). Has been done. Furthermore, pH, supersaturation, Cd (II) and Pb during particle formation
Polyvalent metals such as (II) and urea can also change the crystal phase. FHClaes, Double Peels (W.Peelaers), Internal
It is described in the Conference of Photograph Symposium (ICPS), Tokyo (1967). In the case of silver chloride crystals, addition of a substance that promotes the formation of methylene blue monomer in an aqueous solution results in (110) plane and (11) plane.
1) The appearance of the face
laes), J.Libber, W.Vanassche, Journal of Photographic Science (J.Photogr.Sci.), 21, 39 (197)
It is described in 3). U.S. Patents 4,183,756 and 4,
No. 225,666 discloses that the crystal phase is changed by adding a spectral sensitizing dye to the emulsion after the formation of stable nuclei for silver halide grain formation.

(Problems to be Solved by the Invention) As described above, the crystal phase of silver halide grains is governed by various factors at the time of grain formation, but AP Marchetti and S.S. (SSColli
er), N.P.Cruws, and Photographic Science and Engineering (Photogr.Sci.Eng.), 28,146 (1984), particles having a (100) face are (111). The sensitivity is photographically lower than that of grains having a face, and it has been desired in practice to raise the sensitivity of grains having a (100) face.

An object of the present invention is to provide a process for producing a photographic emulsion comprising silver halide grains having a large proportion of (100) faces under the condition that silver halide grains mainly comprising (111) faces are formed. .

Another object of the present invention is to provide a method for producing a silver halide photographic emulsion having a large number of (100) grain surfaces and high intrinsic sensitivity or spectral sensitivity.

(Means for Solving Problems) The above-mentioned object can be achieved by the following method. That is, the present invention provides a method for producing a silver halide photographic emulsion under the condition of forming a silver halide grain having a ratio of (111) faces of the grain surface of 50% or more. By adding a sensitizing dye, the ratio of (100) faces on the grain surface can be improved. By adding a spectral sensitizing dye, the ratio of (100) faces on the grain surface can be improved by 20% or more. And a method for producing a silver halide photographic emulsion.

The spectral sensitizing dye can be added to the silver halide emulsion at various times before the formation of silver halide grains is completed, and the spectral sensitizing dye or emulsion (halogen composition, kind of additive, etc.) The time of addition can be selected according to the type. The total amount of the spectral sensitizing dye to be added can be added to the reaction solution at the same time as or before the start of grain formation, or the dye to be added can be divided and added in several times. It is also possible to add the dye continuously before the grain formation process is completed.

The spectral sensitizing dye can be dissolved in water or an organic solvent and added to the emulsion. The substantially water-insoluble spectral sensitizing dye can also be used as a dispersion dispersed in an aqueous solvent, as disclosed in Japanese Patent Application No. 59-53867.

As the spectral sensitizing dye used in the present invention, a methine dye is usually used, which includes a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a hemicyanine dye, a styryl dye and hemioxonol. A dye is included. Any of the nuclei normally used for cyanine dyes as a basic heterocyclic nucleus can be applied to these dyes. That is,
Pyrroline nucleus, oxazoline nucleus, thiazoline nucleus, pyrrole nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus,
Imidazole nuclei, tetrazole nuclei, pyridine nuclei, etc .; nuclei in which alicyclic hydrocarbon rings are fused to these nuclei; and nuclei in which aromatic hydrocarbon rings are fused to these nuclei, that is, indolenine nuclei, benzindolenine nuclei , Indole nucleus, benzoxadol nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, benzoselenazole nucleus,
Benzimidazole nucleus, quinoline nucleus, etc. can be applied.
These nuclei may be substituted on carbon atoms.

In the merocyanine dye or the complex merocyanine dye, as a nucleus having a ketomethylene structure, a pyrazolin-5-one nucleus, a thiohydantoin nucleus, 2-thiooxazolidine-2,
5- to 6-membered heterocyclic nuclei such as 4-dione nucleus, thiazolidine-2,4-dione nucleus, rhodanine nucleus and thiobarbituric acid nucleus can be applied.

Among the above dyes, the sensitizing dye particularly useful in the present invention is a cyanine dye. Specific examples of cyanine dyes useful in the present invention include dyes represented by the following general formula (I).

General formula (I) In the formula, Z ₁ and Z ₂ are heterocyclic nuclei usually used for cyanine dyes, particularly thiazole nucleus, thiazoline nucleus, benzothiazole nucleus, naphthothiazole nucleus, oxazole nucleus, oxazoline nucleus, benzoxazole nucleus, naphthoxazole nucleus, tetrazole nucleus, Pyridine nucleus, quinoline nucleus, imidazoline nucleus, imidazole nucleus, benzimidazole nucleus, naphthimidazole nucleus, selenazoline nucleus, selenazole nucleus,
It represents an atomic group necessary for completing a benzoselenazole nucleus, a naphthoselenazole nucleus, an indolenine nucleus, or the like. These nuclei include lower alkyl groups such as methyl groups, halogen atoms, phenyl groups, hydroxy groups, alkoxy groups having 1 to 4 carbon atoms, carboxyl groups, alkoxycarbonyl groups, alkylsulfamoyl groups, alkylcarbamoyl groups, acetyl groups. , An acetoxy group, a cyano group, a trichloromethyl group, a trifluoromethyl group, a nitro group and the like.

L ₁ , L ₂ or L ₃ represents a methine group or a substituted methine group. The substituted methine group, a lower alkyl group such as a methyl group, an ethyl group, a phenyl group, a substituted phenyl group, a methoxy group,
Examples include a methine group substituted with an aralkyl group such as an ethoxy group and a phenethyl group. L ₃ and when R ₂ and m ₁ = 3 L ₂
And L ₂ may be alkylene bridged to form a 5- or 6-membered ring. For example, when alkylene bridged with L ₃ and R ₂ to form a 6-membered ring, it is as follows.

When m ₁ = 3, the following is the case where an alkylene bridge is formed with L ₂ and L ₂ to form a 6-membered ring.

R₁And R₂Is a lower alkyl group, (more preferably having 1 carbon atom)
~ 6 alkyl group); carboxy group, sulfo group, hydro
Xy group, halogen atom, alkoxy having 1 to 4 carbon atoms
Group, phenyl group, substituted alkyl having substituted phenyl group, etc.
A group (preferably alkylene moiety is C₁~ C_FiveGood). example
For example, B-sulfoethyl, γ-sulfopropyl, γ-sulfo
Butyl, S-sulfobutyl, 2- [2- (3-sulfop
Ropoxy) ethoxy] ethyl, 2-hydroxysulfop
Ropil, 2-chlorosulfopropyl, 2-methoxyethyl
2-hydroxyethyl, carboxymethyl, 2-carb
Ruboxyethyl, 2,2,3,3-tetrafluoropropyl,
3,3,3-trifluoroethyl; allyl group and its
Other commonly used N-substituents for cyanine dyes
Represents a substituted alkyl group. m₁Represents 1, 2 or 3.
X₁ Is iodine ion, bromine ion, p-toluene sulfone
For ordinary cyanine dyes such as acid ion and perchlorate ion
Represents an acid anion group. n₁Represents 1 or 2
However, when taking a betaine structure, n₁Is 1.

Specific examples of the cyanine dye useful in the present invention include the following dyes.

As the spectral sensitizing dye, those described in the following other than the above are used. German Patent 929,080, U.S. Patents 2,493,748, 2,503,776, 2,519,001,
2,912,329, 3,656,959, 3,672,897, 3,6
94,217, 4,025,349, 4,046,572, 2,688,54
No. 5, No. 2,977,229, No. 3,397,060, No. 3,522,052, No.
3,527,641, 3,617,293, 3,628,964, 3,66
6,480, 3,672,898, 3,679,428, 3,703,377
No. 3, No. 3,814,609, No. 3,837,862, No. 4,026,707,
British Patents 1,242,588, 1,344,281, 1,507,803
Issue, Japanese Examined Patent Publication No.44-14,030, No.52-24,844, No.43-4936
No. 53-12,375, JP-A Nos. 52-110,618, 52-109,92
5 and 50-80,827.

The amount of sensitizing dye added during the preparation of silver halide emulsion is
Although it cannot be unequivocally described depending on the kind of the additive and the amount of silver halide, it can be used in an amount substantially equivalent to the amount added in the conventional method.

That is, the preferable addition amount of the sensitizing dye is silver halide 1
It is 0.01 to 10 mmol per mole, and more preferably 0.
It is 1 to 1 mmol.

Since the crystal phase of emulsion grains is governed by various conditions during grain formation, the grain formation conditions cannot be unambiguously described by pAg, etc., but the grain surface consists mainly of (111) faces. Grain formation is performed under the conditions for forming silver halide grains. The silver halide grain having a grain surface mainly composed of (111) faces is a grain having a proportion of the (111) face of the grain surface of 50% or more, preferably 75% or more. Under such conditions for grain formation, the (100) plane of the grain surface can be increased by adding a spectral sensitizing dye before grain formation is completed. Although it is difficult to uniquely determine such conditions by pAg, it is usually about pAg8 to 13. By this method, the ratio of (100) faces on the grain surface is 20
%, More preferably 50% or more, and even more preferably 80% or more particles can be obtained.

Further, according to the method of the present invention, the plane ratio of the (100) plane is 20
% Or more, more preferably 50% or more.

The silver halide grains may be monodisperse or polydisperse, and their crystal phase and surface ratio can be directly observed from an electron micrograph of a silver halide emulsion grain by a carbon replica method, and more accurately, the Chemical Society of Japan 1984. , No. 6, page 942 can be used. That is, by measuring the reflection spectrum of a thick liquid emulsion layer to which various amounts of Dye 1 were added, and paying attention to the fact that the dye gives a spectrum that is significantly different on the (100) plane and the (111) plane, Kubelka-Mu
The ratio of the (100) plane and the (111) plane can be calculated by using the equation of nk.

In the silver halide emulsion to which the present invention is applied, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide, silver chloride, etc. may be used. The silver halide grains may have different phases in the inside and the surface layer, may have a multi-phase structure having a junction structure, or may have a uniform phase as a whole. Moreover, they may be mixed.

The grain size of the silver halide is not particularly limited,
The average grain size of silver halide grains (represented by the grain diameter in the case of spherical grains or grains close to spheres, and the edge length in the case of cubic grains as the grain size) is 3μ or less. 0.1 μm or more is preferable. The particle size distribution may be narrow or wide. Also,
Coefficient of variation of particle size distribution is within 20%, preferably 15%
So-called monodisperse silver halide emulsions within can be used in the present invention.

The photographic emulsion used in the present invention is P. grafchides (P.
Glafkides), Chimie er Physique Photogroheque (Paul Montel, 1967), G. Duffin (G.
F.Duffin), Phtograpic Emulsion Chemistry (published by Foucal Press, 1966), VLZelikman, et al., Making and Coating Huotographik (Making and
Coating Photographic Emulsion) (published by Focal Press, 1964) and the like.

That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and as a method of reacting a soluble silver salt and a soluble halogen salt, any of a one-sided mixing method, a simultaneous mixing method and a combination thereof may be used. .

A method of forming grains in the presence of excess silver ions (so-called reverse mixing method) can also be used. PAg in the liquid phase in which silver halide is formed as a form of simultaneous mixing method.
To keep constant, that is, so-called controlled
The double jet method can also be used.

Further, in order to control the growth of grains during the formation of the silver halide grains, as a silver halide solvent, for example, ammonia, rodancali, rodanammon, and a thioether compound (for example, U.S. Pat.Nos. 3,271,157 and 3,574,628).
No. 3, No. 3,704, 130, No. 4,297, 439, No. 4,276, 37
No. 4, etc.), thione compounds (for example, JP-A-53-144,319).
No. 53-82,408, No. 55-77,737, etc.), amine compounds (for example, JP-A No. 54-100,717, etc.) and the like can be used.

In the process of silver halide grain formation or physical ripening,
Cadmium salt, zinc salt, thallium salt, iridium salt or complex salt thereof, rhodium salt or complex salt thereof, iron salt or iron complex salt may be allowed to coexist.

Emulsions are usually freed of soluble salts after grain formation is complete (after precipitation or physical ripening). The means for this is to use gelatin gelation, which has been known for a long time, and to use the Nordel washing method. Inorganic salts consisting of polyvalent anions, such as sodium sulfate, anionic surfactants, anionic polymers (eg polystyrene sulfonic acid), or gelatin derivatives (eg fatty acid acylated gelatin, aromatic acylated gelatin, fragrance). A precipitation method (flourescence) using a group carbamoylated gelatin or the like may be used.

Silver halide emulsions are usually chemically sensitized. For chemical sensitization, for example, H. Frieser edition,
Die Grundlagen del Fotographisien Protese Mitt Gilberhalogeniden (Die
Grundlagen der Photographischen Prozesse mit Silbe
rhalogeniden) (Akademitsushie Fuerragus Gezersiakact 1968) pages 675-734 can be used.

That is, a sulfur sensitization method using a compound containing sulfur capable of reacting with active gelatin or silver (for example, thiosulfate, thioureas, mercapto compounds, rhodanines); a reducing substance (for example, first tin salt, Reduction sensitization using amines, hydrazine derivatives, formamidine sulfinic acid, silane compounds); noble metal compounds (eg, gold complex salts, complex salts of Group VIII metals such as Pt, Ir, Pd) The noble metal sensitizing method to be used can be used alone or in combination.

The morphology of silver halide grains can be known by taking an electron micrograph of the grains by the carbon replica method. The grain size and grain size distribution of the silver halide grains described above can be measured by an optical microscope, an electron microscope, a Coulter counter and a Quantimet image analyzer. For an electron micrograph of silver halide grains and a method for measuring grain size, see “The Theory of the Photog process” edited by TH James, edited by TH James.
raphic Process (Fourth Edition) ") Macmillan Publishing Co., Ltd, 1
977) Chapter 3 Precipitation and Growth of Silver Halide Emul
sion Grains (by CRBerry)
Is shown in.

The photographic emulsion used in the present invention may contain various compounds for the purpose of preventing fog during the production process of the light-sensitive material, during storage or during photographic processing, or stabilizing photographic performance. That is, azoles such as benzothiazolium salts, nitroindazoles, triazoles, benzotriazoles, benzimidazoles (particularly nitro- or halogen-substituted compounds), heterocyclic mercapto compounds such as mercaptothiazoles, mercaptobenzothiazoles, mercapto Benzimidazoles, mercaptothiadiazoles, mercaptotetrazoles (particularly 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines; the above heterocyclic mercapto compounds having a water-soluble group such as a carboxyl group or a sulfone group; a thioketo compound such as Oxazoline thiones; azaindenes such as tetraazaindenes (especially 4-hydroxy-substituted (1,3,3a, 7) tetraazaindenes); benzenethiosulfonic acids; Zensurufuin acid; can be added to many compounds known as antifoggants or stabilizers, such as.

The silver halide photographic emulsion of the present invention is a color coupler such as a cyan coupler, a magenta coupler and a yellow coupler.
A coupler and a compound that disperses the coupler may be included.

That is, a compound capable of forming a color by oxidative coupling with an aromatic primary amine developing agent (for example, a phenylenediamine derivative or an aminophenol derivative) in the color development processing may be contained. For example, magenta couplers include 5-pyrazolone couplers, pyrazolobenzimidazole couplers, cyanoacetylcoumarone couplers, open-chain acylacetonitrile couplers, and the like, and yellow couplers include acylacetamide couplers (for example, benzoylacetanilides, pivaloylacetanilides). , Etc., and cyan couplers include naphthol couplers and phenol couplers. These couplers are preferably non-diffusible ones having a hydrophobic group called a ballast group in the molecule. The coupler may be either 4-equivalent or 2-equivalent with respect to silver ion. Further, a colored coupler having a color correction effect, or a coupler releasing a development inhibitor upon development (so-called DI
R coupler).

In addition to the DIR coupler, a non-colored DIR coupling compound which is colorless in the coupling reaction product and releases a development inhibitor may be contained.

The photographic emulsion used in the present invention is spectrally sensitized with a methine dye or the like in another chemical ripening step before being coated on a suitable support, in addition to being used before completion of grain formation as described above. Good. 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 nuclei normally used for cyanine dyes as a basic heterocyclic nucleus can be applied to these dyes.

A dye that does not have a spectral sensitizing effect by itself, or a substance that does not substantially absorb visible light, together with a sensitizing dye,
A substance exhibiting supersensitization may be included in the emulsion. For example,
Aminostil compounds substituted by nitrogen-containing heterocyclic groups (for example, those described in US Pat. Nos. 2,933,390 and 3,635,721), aromatic organic acid formaldehyde condensates (for example, those described in US Pat. No. 3,743,510), cadmium salts ,
An azaindene compound or the like may be included. US Patent 3,61
5,613, 3,615,641, 3,617,295, 3,635,721
The combinations described in item No. are particularly useful.

Various other additives can be used in the silver halide emulsion used in the present invention. That is, a surfactant, a hardener, a thickener, a dye, an ultraviolet absorber, an antistatic agent, a whitening agent, a desensitizer, a developer, an anti-fading agent, a mordant and the like can be used. Further, a coupler such as a color coupler may be dispersed in oil and used.

For these additives, see RESECH DISCLOSURE, RD-17643, vol.176, pa.
ge 22-31 (December, 1978), “The Theory of
The Photograph Process 4th Edition "(THE THEO
RY OF THE PHOTOGRAPHIC PROCESS, 4th Ed.) TJ James Edition (1977, Macmillan
It is specifically described in Publishing Company (Macmillan Publishing Co. Inc.) and the like.

The binder used in the silver halide emulsion to which the present invention is applied is preferably gelatin (lime-processed gelatin, acid-processed gelatin, etc., but in addition to gelatin, derivative gelatin such as phthalated gelatin, albumin, agar, gum arabic, Cellulose derivatives, polyvinyl acetate, polyacrylamide, polyvinyl alcohol and the like are used.

The silver halide photographic light-sensitive material which can be used in the present invention includes a color positive film, a color paper, a color negative film, a color reversal film (which may or may not contain a coupler), and a plate-making photographic light-sensitive material (for example, lithographic material). Film, litho-dope film, etc., examples of photosensitive materials for cathode ray tube displays (eg, emulsion X-ray recording photosensitive materials, direct and indirect imaging materials using screens), silver salt diffusion transfer process
process) light-sensitive material, color diffusion transfer process light-sensitive material, die transfer process light-sensitive material, silver dye bleaching emulsion, light-sensitive material for recording printout image, photo-developing printout (Direct Print image) ) Photosensitive materials, photothermographic materials, physical development photosensitive materials and the like.

(Examples) Examples will be described below, but the invention is not limited to these examples.

Example 1 First, Sample 1 was prepared as follows.

1000 ml of water, 30 g of inert gelatin and 2 in a reaction vessel
7.5 ml of 5 wt% NH ₃ aqueous solution was added and kept at 50 ° C., and 750 ml of 1NAgNO ₃ aqueous solution and 1NKBr aqueous solution were simultaneously added over 40 minutes at a flow rate of 18.75 ml / min of AgNo ₃ aqueous solution with good stirring. At this time, the silver potential of the reaction solution is always +50 mV vs. 50 ° C.
Keep on SCE (saturated calomel electrode). This silver potential is the pAg value
Equivalent to 7.81. This emulsion was desalted, inert gelatin and water were added, and the pH was adjusted to 6.8 and pAg8.6 at 50 ° C to make 2000 ml. This emulsion has an average equivalent circle diameter of 0.75 μm and (100)
It consisted of monodisperse cubic particles with 100% face ratio.
The coefficient of variation (CV) was 8.7 (emulsion).

Add an aqueous solution of sodium thiosulfate to this emulsion and add 60
It was aged for a minute and sulfur-sensitized. The amount of sodium thiosulfate was adjusted so as to give the highest photographic speed after exposure for 1 second, and was 2.5 mg per 100 g of the above emulsion.

To 100 g of the above emulsion, 6 ml of the methanol solution of the spectral sensitizing dye 1 (2.8 g / 1000 ml) was added, and the mixture was aged for 5 minutes at 40 ° C. with good stirring. Then, a coating aid and a hardener were added and triacetic acid was added. It was coated on a cellulose film base so that AgBr would be 7 g / m ² . The coating emulsion is a tungsten bulb (color temperature 2854
KPN) through BPN42 filter (Fuji Photo Film Co., Ltd. gelatin filter) and color sensitization sensitivity through SC52 filter (Fuji Photo Film Co., Ltd. gelatin filter) and continuous wedge It was exposed for 1 second. The exposed coating emulsion was developed at 20 ° C. for 10 minutes using the following surface developer (MAA-1).

Metol 2.5 g d-Ascorbic acid 10.0 g Potassium bromide 1.0 g Navox 35.0 g Water 1000 ml The sensitivity of the emulsion obtained was indicated by the relative value of the reciprocal of the exposure amount required for the optical density to become fogging plus 0.1.

The results obtained for Sample 1 in this way are shown in Table 1.

Next, sample 2 was similarly processed except that the silver potential of the reaction solution was changed to OmV vs. SCE 2 minutes after the addition of the AgNO ₃ aqueous solution was started in sample 1. This silver potential corresponds to a pAg value of 8.59. This emulsion was a tetradecahedron having a (100) face ratio of 16%. Here, the surface ratio was calculated based on the above-mentioned Kubelka-Munk equation. This emulsion has an average equivalent circle diameter of 0.78
The coefficient of variation (CV) was 9.0 (microemulsion) (emulsion).

Next, sample 3 is AgNO _{3 in the} method for producing the emulsion of sample 1.
Two minutes after the start of the addition of the aqueous solution, 120 ml of a methanol solution of dye 1 (2.8 g / 1000 ml) was added over 36 minutes, and otherwise the same operation as in sample 1 was performed. This emulsion consisted of monodisperse cubic grains having an average equivalent circle diameter of 0.75 μm and a ratio of (100) faces of 100%. The coefficient of variation (CV) was 9.4 (emulsion). An aqueous solution of sodium thiosulfate was added to this emulsion and ripened at 50 ° C. for 60 minutes for sulfur sensitization. The amount of sodium thiosulfate was adjusted to give the highest photographic speed after exposure for 1 second and was 0.9 mg based on 100 g of the above emulsion. A coating aid and a hardening agent were added and coated on a cellulose triacetate film base so that the AgBr was 7 g / m ^2, and the same exposure and treatment as in Sample 1 were performed to obtain a sensitivity value.

The results obtained for Sample 3 are shown in Table 1. Then, in Sample 4, the silver potential of the reaction solution was changed to OmV vs. SCE (pAg8.59) 2 minutes after the addition of the AgNO ₃ aqueous solution was started in the emulsion of Sample 2, and at the same time the methanol solution of Dye 1 ( 2.8 g / 1000 ml) 120 ml was added over 36 minutes, and the same operation as in sample 1 was otherwise performed. This emulsion consisted of monodisperse cubic grains having an average equivalent circle diameter of 0.74 μm and a ratio of (100) faces of 100%. The coefficient of variation (CV) was 9.4 (emulsion). An aqueous solution of sodium thiosulfate was added to this emulsion and ripened at 50 ° C. for 60 minutes for sulfur sensitization. The amount of sodium thiosulfate was adjusted to give the highest photographic speed after exposure for 1 second and was 0.9 mg based on 100 g of the above emulsion. A coating aid and a hardening agent were added and coated on a cellulose triacetate film base so that the AgBr was 7 g / m ^2, and the same exposure and treatment as in Sample 1 were performed to obtain a sensitivity value.

The results obtained for Sample 4 are shown in Table 1.

As shown in Table 1, the addition of the spectral sensitizing dye (Sample 4) under the condition that a tetradecahedron is generated (Sample 2) significantly increases the ratio of the (100) plane to 100%. , The intrinsic sensitivity and the spectral sensitivity were extremely high.

Further, the sensitivity obtained by the present invention is much higher than that obtained by adding the spectral sensitizing dye (Sample 3) under the condition that the (100) plane is obtained (Sample 1). Improved.

(Example 2) Sample 5 was prepared by adding Na to 100 g of the emulsion obtained in Sample 1 of Example 1.
2.6 × 10 ⁻⁷ mol of an aqueous solution of ₃ Au (S ₂ O ₃ ) ₂ was added, and the mixture was aged at 5 ° C. for 60 minutes for gold-sulfur sensitization.

A solution of spectral sensitizing dye 1 in methanol was added to 100 g of the above emulsion (2.
8 g / 1000 ml) and aged for 5 minutes at 40 ° C. with good stirring, then add a coating aid and a hardener, apply as in Example 1, and perform exposure and treatment to obtain a sensitivity value. It was

Sample 6 was prepared by adding 100 g of the emulsion obtained in Sample 3 of Example 1 to Na ₃ Au (S ₂
2.6 × 10 ⁻⁷ mol of an aqueous solution of O ₃ ) ₂ was added, and the mixture was aged at 5 ° C. for 60 minutes for gold-sulfur sensitization. Coating was performed in the same manner as in Sample 3 of Example 1, exposure and treatment were performed, and sensitivity values were obtained.

Sample 7 was prepared by adding 100 g of the emulsion obtained in Sample 4 of Example 1 to Na ₃ Au (S ₂
2.6 × 10 ⁻⁷ mol of an aqueous solution of O ₃ ) ₂ was added and the mixture was aged at 50 ° C. for 60 minutes for gold-sulfur sensitization. Coating was performed in the same manner as in Sample 3 of Example 1, exposure and treatment were performed, and sensitivity values were obtained.

The sensitivity values obtained for Samples 5, 6 and 7 above are shown in Table 2.

As shown in Table 2, the sample 7 according to the present invention obtained an extremely high sensitivity value as compared with the samples 5 and 6 of the conventional method.

(Example 3) First, the sample 8 was created as follows.

In a reaction vessel 800 ml H ₂ O, 60 g inert gelatin, KBr13
g and 1% by weight of 5.8 ml of a compound having the following structural formula were added and kept at 75 ° C., Well with stirring 1.2NAgNO ₃ solution 1000 ml, was added connexion cotton simultaneously 60 minutes 1.4NKBr aqueous solution containing 0.48 wt% of KI in aqueous AgNO ₃ solution and KBr solution flow rate 16.7 ml / min. At this time, the silver potential of the reaction solution was -90 mV with respect to the saturated calomel electrode. This silver potential corresponds to a pAg value of 9.17. This emulsion is desalted, inert gelatin and H ₂ O are added, and the temperature is 50 ° C.
The pH was adjusted to 6.8 and pAg8.6 to 2000 ml. This emulsion has an average equivalent circle diameter of 0.97 μm and a monodisperse 8 ratio of (111) plane of 100%.
It consisted of faced grains. The coefficient of variation was 5.7%.
Keep this emulsion at 50 ° C and add it to an aqueous solution of Na ₃ Au (S ₂ O ₃ ) ₂
Sulfur sensitized.

Methylcellosolve solution of Dye 8 (0.57 g) in 80 g of the above emulsion
/ 1000 ml) was added, and the mixture was aged at 40 ° C. for 5 minutes with good stirring, and then a coating aid and a hardening agent were added and the mixture was coated on a cellulose triacetate film base. This emulsion was prepared as in Example 1 above.
Exposure and development were carried out in the same manner as above to obtain a sensitivity value (Sample 8).

Then, in the same manner as in Sample 8, in the formation of particles, 400 ml of the methylcellosolve solution of dye 8 (0.57 g / 1000 ml) was added from 35 minutes after starting the addition of the AgNO ₃ aqueous solution for 35 minutes. The resulting emulsion consisted of monodisperse tetradecahedral grains having an average equivalent circle diameter of 0.96 μm. The coefficient of variation was 7.9%. (100)
The face ratio was 23%. This emulsion was treated with gold in the same manner as sample 8.
After sulfur sensitization, a coating aid and a hardener were added and coated. The sensitivity values obtained are shown in Table 3 together with Sample 8 (Sample 9).

From Table 3, it was found that according to the present invention, particles having a large number of (100) planes were obtained, and intrinsic sensitivity and spectral sensitivity were extremely high.

Example 4 1000 ml H ₂ O, 30 g inert gelatin and 25 in a reaction vessel.
7.5% by weight of NH ₃ aqueous solution was added and kept at 50 ° C., and 750 ml of 1NAgNO ₃ aqueous solution and 1NKBr aqueous solution were simultaneously added over 40 minutes at a flow rate of 18.75 ml / min of AgNO ₃ aqueous solution with good stirring. At this time, the silver potential of the reaction solution was always kept at +50 mV, OmV, -40 mV and -80 mV as shown in Table 4 with respect to the saturated calomel electrode. Each of these silver potentials has a pAg value of 7.8.
Corresponds to 1, 8.59, 9.21, and 9.84 (Samples 10, 11, 1
2, 13).

In Samples 10 to 13, 2 minutes after the start of addition of the AgNO ₃ aqueous solution and 36 minutes later, a methanol solution of dye 5 (2.8 g / 100
0 ml) was added to 120 ml.

The silver potential of the reaction solution was maintained in the same manner as in Samples 10 to 13 (Samples 14 to 17).

With respect to the obtained samples 10 to 17, the plane ratio of the (100) plane was calculated based on the above-mentioned Kubelka-Munk equation, and the results are shown in Table 4.

From Table 4, according to the present invention, in the high pAg region (100)
It has been found that emulsion grains with a higher surface ratio are obtained.

Claims (1)

[Claims] 1. A method for producing a silver halide photographic emulsion under conditions for forming a silver halide grain having a ratio of (111) faces of the grain surface of 50% or more, before the grain formation is completed. By adding a spectral sensitizing dye, the ratio of (100) faces on the grain surface can be improved. By adding a spectral sensitizing dye, the ratio of (100) faces on the grain surface can be improved by 20% or more. And a method for producing a silver halide photographic emulsion.