JP3191193B2 - Method for producing silver halide photographic emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silver halide photographic emulsion, and more particularly to a method for producing a silver halide photographic emulsion having improved photographic characteristics such as sensitivity and illuminance failure by metal doping. Things.

[0002]

2. Description of the Related Art In recent years, demands for higher sensitivity and higher image quality of silver halide photographic materials have been increasing. In response to such demands, in order to improve the photosensitive characteristics of silver halide emulsions, there is a need for a technique for controlling charge carriers (carriers) in silver halide grains involved in the photosensitive process. One of the effective means for carrier control is metal doping.

For example, it has been reported by Leubner that an Ir complex doped with silver halide exhibits an electron trapping property (The Journal of Photographic Science Vo.
l. 31, 93 (1983)). Further, for example, a technique using divalent iron ions as a hole-trapping dopant is disclosed in Japanese Patent Laid-Open No. 1-121844.
Issue.

[0004] As described above, it is known that metal doping traps carriers such as electrons and holes that are deeply involved in the photosensitive process, thereby improving the photographic characteristics of silver halide emulsions.

[0005] Further, studies have been made to control the distribution of the dopant in the silver halide grains to sufficiently bring out the effect of metal doping.

For example, JP-A-3-15040 discloses an example in which the region where iridium ions are present is limited below the grain surface. JP-A-1-121844 discloses a method in which divalent iron ions are added to silver halide. In this example, doping is performed on the portion having the smallest band gap energy.

However, the conventional technique has not been able to obtain a sufficient effect of controlling the distribution of the metal dopant.

[0008] For example, the technique disclosed in Japanese Patent Application Laid-Open No. H3-15040 is to stop the addition of dopant during grain formation early so as to prevent the dopant from being exposed on the surface, or to perform ripening after grain formation. However, simply stopping the addition of the metal dopant during grain formation forms a layer that does not sufficiently contain the metal dopant because a part of the dopant added up to that time remains without being doped in the reaction solution. I can't let that happen.

Although the amount of dopant contained in the vicinity of the grain surface may be reduced to some extent by these methods, the effect is small, and it can be applied only to a limited distribution form. This technology cannot be applied to control. It is also difficult to apply a dopant concentration difference within the grains.

The technique disclosed in Japanese Patent Application Laid-Open No. 1-121844 is that a grain washing step is provided after doping, and then the grain growth is continued without adding a dopant. In this method, the doping amount can be changed stepwise. However, in the step of washing the emulsion with water, the effect is small because the metal dopant is adsorbed on the surface of the silver halide grains or on the protective colloid. Further, in order to change the doping amount in the particles in several stages, it is necessary to perform water washing by the number of times. Further, it cannot be applied to continuously changing the doping amount.

As described above, in the conventional method, the dopant content distribution in the grains cannot be effectively controlled.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a silver halide photographic emulsion in which the effect of improving photographic properties by metal doping is further improved by controlling the distribution of the metal dopant in the grains. It is.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a silver halide photographic emulsion containing polyvalent metal cations in silver halide grains. The present invention has been attained by a method for producing a silver halide photographic emulsion, characterized in that the distribution of the metal ions in the grains is controlled by changing the ligand concentration.

In the present invention, controlling the distribution of metal ions in the grains means changing the doping amount of the dopant from the grain surface toward the inside, that is, the amount of the dopant contained per mole of silver halide. . The doping amount may change continuously or may change stepwise, but preferably changes stepwise.
Also, the portion with the smallest doping amount is 1 / of the highest portion.
The doping amount is preferably 5 or less.

The most preferred embodiment of the dopant distribution of the present invention is that a layer having a doping amount of 1 × 10 ⁻⁵ mol / Agmol or more inside a grain and a doping amount of 2 × 10 ⁻⁶ mo on the outermost surface of the grain.
This is the case with a layer of l / Agmol or less. The outermost layer,
It is preferably at least 10%, more preferably at least 20% of the total particle volume.

The method for producing a silver halide emulsion of the present invention can be applied to a silver halide emulsion having an arbitrary halide composition. Further, the production method of the present invention can be applied to silver halide grains having an arbitrary grain size, and the preferred range is 0.1 μm to 3.0 μm. However, in the present invention, the particle size is a value converted into the side length of a cube having the same volume.

The terms "doping" or "doping" refer to the inclusion of substances other than silver or halide ions in silver halide grains.

The term "dopant" refers to compounds that dope silver halide grains.

The term "metal dopant" refers to a polyvalent metal compound that is doped into silver halide grains.

The term "doping rate" refers to the ratio of dopant incorporated in the silver halide to the dopant added.

In the present invention, the dopant is Mg, A
1, Ca, Sc, Ti, V, Cr, Mn, Fe, Co,
Ni, Cu, Zn, Ga, Ge, Sr, Y, Zr, N
b, Mo, Tc, Ru, Rh, Pd, Cd, In, S
n, Ba, Ce, Eu, W, Re, Os, Ir, Pt,
Compounds containing metal ions such as Hg, Tl, Pd, Bi, etc. can be preferably used. Particularly preferred are compounds of Pb, In, and Ga.

The additive amount of the dopant is 1 in the total silver halide amount.
The range is preferably 1 × 10 ⁻⁷ mol to 5 × 10 ⁻⁴ mol, and more preferably 5 × 10 ⁻⁶ mol to 2 × 10 ⁻⁴ mol, per mol.

The ligand whose concentration is changed in the present invention is preferably bulky. This is presumably because the bulkier the complex formed with the polyvalent metal ion, the smaller the doping ratio to silver halide, that is, the larger the doping ratio change due to the change in ligand concentration.

Specifically, a ligand having 4 or less constituent atoms, such as ammonia, has almost no effect, and a ligand having 7 or more constituent atoms is preferable, and a ligand having 12 or more constituent atoms is preferable. Is more preferred. Chelating ligands having two or more coordination sites are particularly preferred from the viewpoint of stability. As the most preferred ligand, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediamine-N- (β-hydroxyethyl) -N′-triacetic acid, 1,3-propylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, cyclohexanediaminetetraacetic acid Acetic acid, 1,2-diaminopropanetetraacetic acid, 1,2-diaminopropan-2-ol-tetraacetic acid, ethyletherdiaminetetraacetic acid, glycoletherdiaminetetraacetic acid, ethylenediaminetetrapropionic acid, phenylenediaminetetraacetic acid, ethylenediaminetetramethylene Phosphonic acid, diethylenetriamine pentamethylenephosphonic acid, nitrilotriacetic acid, methyliminodiacetic acid, nitrilotripropionic acid, nitrilotrimethylenephosphonic acid, iminodimethylenephosphonic acid, hydroxy Ethyliminodimethylenephosphonic acid, thyrone, triethylenetetramine, and alkali metal salts and ammonium salts of these compounds. Among them, nitrilotriacetic acid, eletindiaminetetraacetic acid, cyclohexanediaminetetraacetic acid, thyrone, triethylenetetramine and salts thereof are particularly preferred.

As a mode of changing the ligand concentration, a method of gradually increasing the concentration during the formation of the particles and a method of adding the ligand during the formation of the particles are preferably used. The former method can be preferably used to continuously change the doping amount, and the latter method can be preferably used to change stepwise.

The distribution of the metal dopant in the silver halide grains can be determined by dissolving the grains little by little from the surface to the inside and measuring the dopant content of each part. Specifically, after dissolving the emulsion with an appropriate silver halide solvent, quantitative analysis of the metal dopant in the dissolved portion is performed. At the same time, particle measurements of the particles before and after dissolution are performed. This is divided into 1 to 7% of particle volume, 50% of particle volume
This is performed over the above.

As the silver halide solvent, an alkali halide solution, a thiosulfate solution, an alkali thiocyanate solution, an alkali cyanide solution, an ammonia solution, or the like can be used.

As a method for analyzing metal ions, an atomic absorption method, an ICP emission spectrometry, an ICP-mass spectrometry, a glow discharge mass spectrometry, or the like can be used.

The method for producing a silver halide photographic emulsion of the present invention is preferably applied to the production of a monodispersed silver halide emulsion. A monodisperse silver halide emulsion is one in which the weight of silver halide contained in a grain size range of ± 20% around the average grain size d is 70% or more of the total weight of silver halide. It is 80% or more, more preferably 90% or more.

The monodispersed emulsion has a distribution width defined by multiplying the value obtained by dividing the standard deviation of the particle size by the average particle size by 100, and has a distribution width of 20% or less, more preferably 15% or less. belongs to. The particle size in the present invention means the side length of a cube having the same volume as the particles.

A silver halide photographic emulsion obtained by the method for producing a silver halide emulsion of the present invention (hereinafter also referred to as a silver halide photographic emulsion obtained by the method of the present invention)
May be normal crystals such as cubic, tetrahedral, and octahedral,
It may be twinned. Further, a mixture thereof may be used.

In the case of twins, the ratio of the diameter of the grain equivalent to the projected area equivalent to the projected area of the grain to the grain thickness of 1 to 20 is 60% of the projected area.
% Is preferable. Further, the ratio between the diameter of the grain equivalent to the projected area equivalent to the circle and the thickness of the grain is preferably 1.2 or more and less than 8.0, and particularly preferably 1.5 or more and less than 5.0.

Monodisperse normal crystal emulsions are disclosed, for example, in
-177535, 60-138538, 59-52238, 60-14333
No. 1, No. 60-35726, No. 60-258536, and No. 61-14636.

Monodisperse twin emulsions are described, for example, in JP-A-61-1.
It can be obtained by referring to the method of growing a spherical seed emulsion disclosed in Japanese Patent No. 4636.

In the method for producing a silver halide photographic emulsion of the present invention, an apparatus described in JP-A-62-160128 is preferably used.

For growth, it is preferable to add an aqueous silver nitrate solution and an aqueous halide solution by a double jet method. The iodine can also be supplied into the system as silver iodide. The addition rate is preferably such that no new nuclei are generated, and at such a rate that the size distribution does not spread due to Ostwald ripening, that is, 30 to 100% of the rate at which new nuclei are generated.

As another condition for enlarging the particles, as shown in the 88th Annual Meeting of the Photographic Society of Japan 1983,
A method of adding silver halide fine particles, dissolving and recrystallizing the particles to enlarge them can be used.

The growth conditions for the silver halide emulsion include pA
g5-11, temperature 40-85 ° C, pH 1.5-12 are preferred.

The silver halide photographic emulsion obtained by the production method of the present invention is preferably desalted by a known method after the formation of the silver halide grains. As a desalting method, for example, an agglomerated gelatin agent or the like may be used, or a noodle washing method performed by gelling gelatin may be used, and inorganic salts composed of polyvalent anions, such as sodium sulfate and anion Coagulation method using anionic surfactants and anionic polymers (for example, polystyrene sulfonic acid), and sedimentation method (Flocculation method) using gelatin derivatives (for example, acylated gelatin, carbamoylated gelatin, etc.) Is also good.

The desalted silver halide grains are redispersed in a gelatin solution to prepare a silver halide emulsion.

The silver halide photographic emulsion obtained by the production method of the present invention can be preferably used for a silver halide color photographic light-sensitive material.

When a color photographic light-sensitive material is constituted by using the silver halide photographic emulsion obtained by the production method of the present invention, the silver halide emulsion which has been subjected to physical ripening, chemical ripening and spectral sensitization is used. use. The additive used in such a process is Research Disclosure No. 176
43, No. 18716 and No. 308119 (hereinafter referred to as RD1764, respectively)
3, RD18716 and RD308119). The places to be described are shown below.

[Items] [RD308119] [RD17643] [RD18716] Chemical sensitizer 996 III-A 23 648 Spectral sensitizer 996 IV-A-A, B, C, D, H, I, J Item 23-24 648-9 Supersensitizer 996 IV-AE, J Item 23-24 648-9 Antifoggant 998 VI 24-25 649 Stabilizer 998 VI 24-25 649 According to the production method of the present invention, Known photographic additives that can be used in forming a color photographic light-sensitive material using the obtained silver halide photographic emulsion are also described in the above-mentioned Research Disclosure. The relevant sections are described below.

[Item] [Page of RD308119] [RD17643] [RD18716] Anti-turbidity agent 1002 VII-I 25 650 Dye image stabilizer 1001 VII-J 25 Whitening agent 998 V 24 UV absorber 1003 VIII- C, XIIIC 25-26 Light absorber 1003 VIII 25-26 Light scattering agent 1003 VIII Filter dye 1003 VIII 25-26 Binder 1003 IX 26 651 Static inhibitor 1006 XIII 27 650 Hardener 1004 X 26 651 Plasticizer 1006 XII 27 650 Lubricant 1006 XII 27 650 Activator / Coating aid 1005 XI 26-27 650 Matting agent 1007 XVI Developer (contained in photosensitive material) 1011 XXB Item Silver halide photographic emulsion obtained by the production method of the present invention When a color photographic light-sensitive material is used, various couplers can be used, and specific examples thereof are described in Research Disclosure below. The relevant sections are described below.

[Items] [RD308119] [RD17643] Yellow coupler 1001 VII-D VIIC-G Magenta coupler 1001 VII-D VIIC-G Cyan coupler 1001 VII-D VIIC-G Colored coupler 1002 VII- Section G, Section VIIG, DIR coupler 1001 Section VII-F, Section VIIF BAR coupler 1002, Section VII-F Other useful residues Release coupler 1001, Section VII-F, Alkali-soluble coupler 1001, Section VII-E Halogenation obtained by the production method of the present invention Additives used in forming a color photographic light-sensitive material using a silver photographic emulsion can be added by a dispersion method described in RD308119, page 1007, section XIV.

When a color photographic light-sensitive material is constituted by using a silver halide photographic emulsion obtained by the production method of the present invention, the aforementioned RD17643, page 28, RD18716, pages 647-8 and RD3081 are used.
The support described in section XVII on page 191009 can be used.

The color photographic light-sensitive material using the silver halide photographic emulsion obtained by the production method of the present invention includes:
An auxiliary layer such as a filter layer or an intermediate layer described in RD308119VII-K can be provided.

The color photographic light-sensitive material using the silver halide photographic emulsion obtained by the production method of the present invention is the same as that of the aforementioned RD.
Various layer configurations such as a normal layer, a reverse layer, and a unit configuration described in the section 308119VII-K can be adopted.

The silver halide photographic emulsion obtained by the production method of the present invention is represented by a general or movie color negative film, a slide or television color reversal film, a color paper, a color positive film and a color reversal paper. It can be preferably applied to various color photographic light-sensitive materials.

The color photographic light-sensitive material using the silver halide photographic emulsion obtained by the production method of the present invention is the same as that of the aforementioned RD17.
643 pages 28 to 29, RD18716 page 615 and RD308119 can be developed by the usual method described in XIX.

[0051]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Preparation of Comparative Emulsion A While maintaining Solution A at 70 ° C., Solution B and Solution C-1 were added at a rate as shown in Table 1 using a controlled double jet method. At that time, pAg was controlled as shown in Table 1 using the solution D. When all the solution B was added, the addition was terminated, and desalting and redispersion were carried out by a conventional method. This emulsion is referred to as Emulsion A.

Preparation of Comparative Emulsion B Emulsion B was prepared in the same manner as Emulsion A except that Solution C-2 was used instead of Solution C-1.

Preparation of Comparative Emulsion C Emulsion C was prepared in the same manner as Emulsion B, except that the liquid C-2 was changed to the liquid C-1 at point No. 13 in Table 1.

Preparation of Comparative Emulsion D Emulsion D was prepared in the same manner as Emulsion B, except that the desalting and washing operation was performed during grain growth as follows.

The addition was interrupted once at the point of No. 13 in Table 1, the temperature was lowered to 40 ° C., and 2800 ml of a 5% aqueous solution of Kao Atlas Demol N and 2000 ml of a 20% aqueous magnesium sulfate solution were added as precipitants. After standing for a while, the supernatant was decanted. Thereafter, 15.4 liters of pure water was added and the mixture was stirred, and 800 ml of a 20% aqueous solution of magnesium sulfate was further added to precipitate the emulsion again, and the supernatant was decanted. To the precipitate, 9.0 liter of an aqueous solution containing 144.0 g of ossein gelatin was added, and the temperature was raised again to 70 ° C. to disperse. Then, pAg was adjusted to 9.16 with solution D, and solution C-1 was used instead of solution C-2. The addition was restarted from the point of No. 13 using.

Preparation of Emulsion E of the Invention Emulsion B except that E-1 solution was added at the point of No. 13 in Table 1.
Emulsion E was prepared in the same manner as described above.

Preparation of Emulsion F of the Invention Emulsion B except that E-2 solution was added at the point of No. 13 in Table 1.
Emulsion F was prepared in the same manner as described above.

Preparation of Comparative Emulsion G Emulsion G was prepared in the same manner as Emulsion B except that Solution C-3 was used instead of Solution C-2.

Preparation of Comparative Emulsion H Emulsion H was prepared in the same manner as Emulsion C except that Solution C-3 was used instead of Solution C-2.

Preparation of Comparative Emulsion I Emulsion I was prepared in the same manner as Emulsion D except that Solution C-3 was used instead of Solution C-2.

Preparation of Comparative Emulsion J Emulsion J was prepared in the same manner as Emulsion E except that Solution C-3 was used instead of Solution C-2.

Preparation of Comparative Emulsion K Emulsion K was prepared in the same manner as Emulsion F except that Solution C-3 was used instead of Solution C-2.

The emulsions A to K were found to be octahedral grains having an average grain size of 1.0 μm by observation with an electron microscope.

Determination of Metal Dopants Gelatin Decomposition of Emulsions A to K with Gelatin-Decomposing Enzyme
After washing with nitric acid, dissolution of particles and metal dopant analysis were performed using a 1.0N Na ₂ S ₂ O ₃ solution. The dissolution method is as follows: about 2 g of silver halide sample, 1.0 N Na
_{A 2} S ₂ O ₃ solution is added at a rate of about _{2 to} 20 ml, and the mixture is stirred at room temperature for 30 minutes, and the solid phase and the liquid phase are separated by centrifugation and filtration.
This was repeated as appropriate, and the particle size before and after dissolution was measured by an electron microscope.

The solution obtained by dissolution was used as a sample for metal dopant determination, and Ag and Pb were determined by ICP emission spectrometry.
Was quantitatively analyzed. 1.00 μm to 0.93 μm as surface layer
The average doping amount of the dissolving portion (corresponding to 20.5% dissolution from the particle surface), the average doping amount of the dissolving portion of 0.78 μm to 0.40 μm as the inner layer and the outermost surface layer where the doping amount is less than 2 × 10 ⁻⁶ mol , The volume ratio to the total particle volume.

Evaluation of sensitivity After emulsions A to F were optimally chemically sensitized with hypo,
An appropriate amount of hydroxy-6-methyl-1,3,3a, 7-tetrazaindene, polyvinylpyrrolidone, dioctyl sodium sulfosuccinate as a coating aid, and 1,2-bis (vinylsulfonyl) ethane as a hardening agent are added, respectively. It was applied on a cellulose triacetate base to obtain a sample for sensitometry.
These samples were exposed through an optical wedge and a filter under two conditions of an exposure amount of 32 CMS and an exposure time of 1/100 second and 8 seconds, and the following processing was performed.

[0068] Developer Metol 2.5g L-Ascorbic acid 10.0g Sodium metaborate tetrahydrate 35.0g Potassium bromide 1.0g 1000.0ml in pure water Stop solution Acetic acid (3%) Fixer Konica Fix (Konica Corporation) Each developed The density of the sample was measured using an optical densitometer to determine the sensitivity. Sensitivity is minimum optical density + 0.1
The density was determined as the reciprocal of the exposure amount (exact numerical value) giving the density of Emulsion A, and the sensitivity of Emulsion A was set to 100 and converted to a relative value. Table 2 shows the evaluation results of each emulsion.

Solution A Ossein gelatin 137.0 g Polyisopropylene-polyoxyethylene-succinate sodium salt 10% methanol solution 20.0 ml Silver bromide normal seed emulsion (average particle size 0.275 μm) 0.1469 mol equivalent (Ossein Pure water 6614.0ml B solution Silver nitrate 1175.0g Pure water 2305.7ml C-1 solution Ossein gelatin 60.0g Potassium bromide 1049.7g Potassium iodide 29.9g Pure water 3000.0ml C-2 solution Ossein Gelatin 60.0 g Potassium bromide 1049.7 g Potassium iodide 29.9 g Lead nitrate 298.1 mg 3000.0 ml with pure water C-3 solution Ossein gelatin 60.0 g Potassium bromide 1049.7 g Potassium iodide 29.9 g Lead nitrate 11.92 mg Pure water 3000.0 ml Solution D 1.75N Potassium bromide 500.0ml E-1 Solution Sodium acetate dihydrate 9.6g Pure water 300.0ml E-2 Solution Nitrilotriacetic acid 13.5g Pure water 100.0ml 2.0N Potassium hydroxide 201.6ml

[0070]

[Table 1]

[0071]

[Table 2]

As shown in Table 2, in the emulsions E, F, J, and K to which the ligands were added, the doping amount of the grain surface layer was reduced. , 8 "sensitivity improves low light failure characteristics.

In comparison between Emulsions E and F, Emulsion F in which the doping amount of the outermost surface layer is small and the volume of the outermost surface layer having a low doping amount is larger is higher.

In the comparison between Emulsion E and Emulsion J and Emulsion F and Emulsion K, in the case of Emulsion J and K with a small addition amount, since the addition amount is small, the doped layer of the surface layer is smaller than that of Emulsion E and F. Since the doping amount of the inner layer is small, the improvement effect is small.

[0075]

According to the present invention, it is possible to provide a method for producing a silver halide photographic emulsion in which the effect of improving the photographic properties by metal doping is further improved by controlling the distribution of the metal dopant in the grains.

Claims (1)

(57) [Claims] 1. A method for producing a silver halide photographic emulsion containing a polyvalent metal cation in silver halide grains,
A method for producing a silver halide photographic emulsion, wherein the distribution of the metal ions in the grains is controlled by changing the ligand concentration in the reaction solution during the grain formation process.